interleukin 6 (interferon, beta 2)

C Subfamily
CC Subfamily
CXC Subfamily
CX3C Subfamily

Chemokines

gp130 (IL6ST) shared
IL13RA1 shared
IL3RB (CSF2RB) shared
ILRG shared

interleukin 18
interleukin 18 proprotein
interleukin 1 alpha
interleukin 1, alpha proprotein
interleukin 1 beta
interleukin 1, beta proprotein

interleukin 17
interleukin 17b
interleukin 17E
interleukin 17E isoform 1

IL-1 Family /IL-17 Family

interleukin 10
interleukin 19
interleukin 19 isoform 2
interleukin 20
interleukin 22
interleukin 24
interleukin 24 isoform 1
interleukin 28A
interleukin 28B
interleukin 29

IL-10 Family

interferon alpha family, gene 1
interferon, alpha 1
interferon beta
interferon, beta 1
interferon epsilon 1
interferon, epsilon 1
interferon gamma
interferon, gamma
interferon kappa
interferon, kappa
interferon, omega 1

Interferon Family

CSF1 Egf Flt3l
FLT3LG HGF Kitl
KITLG Pdgfa PDGFB
PDGFC Pdgfd PLEKHQ1
VEGF Vegfa VEGFB
VEGFC

PDGF Family

AMH Bmp2 Bmp7
GDF5 Inhba INHBB
INHBC INHBE Tgfb1
TGFB2 TGFB3

TGF-β Family

CD40LG Eda Fasl
FASLG Lta LTB
TNF Tnfsf10 Tnfsf11
TNFSF12 Tnfsf13 TNFSF13B
Tnfsf14 TNFSF18 TNFSF4
TNFSF7 TNFSF8 TNFSF9

TNF Family

INTERLEUKIN 6 (INTERFERON, BETA 2)

LATEST LITERATURE

1: British journal of cancer, 2010 Sep 7, 103(6)
Loss of tumoral expression of soluble IL-6 receptor is associated with disease progression in colorectal cancer.

[Abstract]Background:Interleukin-6 (IL-6) binds both the membrane and soluble forms of the IL-6 receptor (sIL-6R), which induces a complex with gp130, and proliferation of tumour cells. The aim of this study is to clarify the relationship between tumoral sIL-6R expression and disease progression in colorectal cancer patients.Methods:We measured tissue concentrations of sIL-6R in tumour and normal mucosa from 161 colorectal cancer patients undergoing surgery, and in supernatants from colon cancer cell lines. The expression of IL-6, IL-6R and gp130 was evaluated by immunohistochemical analysis.Results:Loss of tumour expression of sIL-6R as defined by sIL-6R Ca/N ratio <1.0 was significantly associated with factors reflecting disease progression, and was an independent prognostic factor not only in all the patients in this study, but also in the patients with curative intent. Colon cancer cell lines produced sIL-6R in vitro, and the production of sIL-6R in cancer cell lines was stimulated by cytokine stimulation. Immunohistochemistry revealed that loss of tumour expression of sIL-6R was significantly inversely correlated with intense IL-6 expression in the cytoplasm of cancer cells. In addition, tumoral IL-1beta expression was significantly correlated with sIL-6R expression.Conclusion:Loss of tumour expression of sIL-6R is associated with colorectal cancer disease progression.

2: American journal of physiology. Endocrinology and metabolism, 2010 Sep 7, 9(17)
IL-6 selectively stimulates fat metabolism in human skeletal muscle.

[Abstract]Interleukin (IL)-6 is chronically elevated in type 2 diabetes but also during exercise. However, the exact metabolic role, and hence the physiological significance, has not been elucidated. The objective of this study was to investigate the in vivo effect of rhIL-6 on human fat and glucose metabolism and signalling of both adipose tissue and skeletal muscle. Eight healthy post-absorptive males were infused with either rhIL-6 or saline for 4 hours eliciting IL-6 levels of ~40 and ~1 pg mL(-1), respectively. Systemic, skeletal muscle, and adipose tissue fat and glucose metabolism was assessed before, during, and 2 hours after cessation of the infusion. Glucose metabolism was unaffected by rhIL-6. In contrast, rhIL-6 increased systemic fatty acid oxidation ~2-fold after 60 min and it remained elevated even 2 hours after the infusion. The increase in oxidation was followed by an increase in systemic lipolysis. Adipose tissue lipolysis and fatty acid kinetics were unchanged with rhIL-6 compared to saline infusion. Conversely, rhIL-6 infusion caused an increase in skeletal muscle unidirectional fatty acid and glycerol release, indicative of an increase in lipolysis. The increased lipolysis in muscle could account for the systemic changes. Skeletal muscle signalling increased after 1 hour of rhIL-6 infusion, indicated by a 4-fold increase in p-STAT3/STAT3 ratio, whereas no changes in phosphorylated AMPK or ACC levels could be observed. Our findings suggest that an acute increase in IL-6 at a normo-physiological level selectively stimulates lipolysis in skeletal muscle whereas adipose tissue is unaffected.

3: PLoS biology, 2010, 8(8)
IL-6 and IL-10 Anti-Inflammatory Activity Links Exercise to Hypothalamic Insulin and Leptin Sensitivity through IKKbeta and ER Stress Inhibition.

[Abstract]Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKbeta activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKbeta/NF-kappaB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance. This molecular mechanism, mediated by physical activity, involves the anti-inflammatory protein IL-10, a core inhibitor of IKKbeta/NF-kappaB signaling and ER stress. We report that exercise and recombinant IL-6 requires IL-10 expression to suppress hyperphagia-related obesity. Moreover, in contrast to control mice, exercise failed to reverse the pharmacological activation of IKKbeta and ER stress in C3H/HeJ mice deficient in hypothalamic IL-6 and IL-10 signaling. Hence, inflammatory signaling in the hypothalamus links beneficial physiological effects of exercise to the central action of insulin and leptin.

4: Virology, 2010 Aug 24, 285(35)
IL-6-mediated intersubgenotypic variation of interferon sensitivity in hepatitis C virus genotype 2a/2b chimeric clones.

[Abstract]Mechanisms of difference in interferon sensitivity between hepatitis C virus (HCV) strains have yet to be clarified. Here, we constructed an infectious genotype2b clone and analyzed differences in interferon-alpha sensitivity between HCV-2b and 2a-JFH1 clones using intergenotypic homologous recombination. The HCV-2b/JFH1 chimeric virus able to infect Huh7.5.1 cells and was significantly more sensitive to IFN than JFH1. IFN-induced expression of MxA and 25-OAS was significantly lower in JFH1 than in 2b/JFH1-infected cells. In JFH1-infected cells, expression of SOCS3 and its inducer, IL-6, was significantly higher than in 2b/JFH1-infected cells. The IFN-resistance of JFH1 cells was negated by siRNA-knock down of SOCS3 expression and by pretreatment with anti-IL6 antibody. In conclusion, intergenotypic differences of IFN sensitivity of HCV may be attributable to the sequences of HCV structural proteins and can be determined by SOCS3 and IL-6 expression levels.

5: TheScientificWorldJournal, 2010, 10(35)
Selective Inhibitors of Kv11.1 Regulate IL-6 Expression by Macrophages in Response to TLR/IL-1R Ligands.

[Abstract]The mechanism by which the platelet-endothelial cell adhesion molecule PECAM-1 regulates leukodiapedesis, vascular endothelial integrity, and proinflammatory cytokine expression in vivo is not known. We recently identified PECAM-1 as a negative regulator of Kv11.1, a specific voltage-gated potassium channel that functioned in human macrophages to reset a resting membrane potential following depolarization. We demonstrate here that dofetilide (DOF), a selective inhibitor of the Kv11.1 current, had a profound inhibitory effect on neutrophil recruitment in mice following TLR/IL-1R-elicited peritonitis or intrascrotal injection of IL-1 Beta, but had no effect on responses seen with TNF alpha. Furthermore, inhibitors of Kv11.1 (DOF, E4031, and astemizole), but not Kv1.3 (margatoxin), suppressed the expression of IL-6 and MCP-1 cytokines by murine resident peritoneal macrophages, while again having no effect on TNF alpha. In contrast, IL-6 expression by peritoneal mesothelial cells was unaffected. Using murine P388 cells, which lack endogenous C/EBP Beta expression and are unresponsive to LPS for the expression of both IL-6 and MCP-1, we observed that DOF inhibited LPS-induced expression of IL-6 mRNA following ectopic expression of wild-type C/EBP Beta, but not a serine-64 point mutant. Finally, DOF inhibited the constitutive activation of cdk2 in murine peritoneal macrophages; cdk2 is known to phosphorylate C/EBP Beta at serine-64. Taken together, our results implicate a potential role for Kv11.1 in regulating cdk2 and C/EBP Beta activity, where robust transactivation of both IL-6 and MCP-1 transcription is known to be dependent on serine-64 of C/EBP Beta. Our data might also explain the altered phenotypes displayed by PECAM-1 knockout mice in several disease models.

6: Molecular bioSystems, 2010 Aug 23, 285(35)
Long-term subcutaneous microdialysis sampling and qRT-PCR of MCP-1, IL-6 and IL-10 in freely-moving rats.

[Abstract]Cytokines are important mediators of the wound healing response. However, sampling of cytokines from the interstitial fluid at a healing wound site in experimental animals is a challenge. Microdialysis sampling is an in vivo collection option for this purpose as it permits continuous sampling, while remaining contiguous with the wound microenvironment. The polymeric membrane of the microdialysis probe is a foreign material thus allowing a unique approach to sample cytokines generated during a foreign body response (FBR). The focus of these studies was to use microdialysis sampling to collect cytokines from a microdialysis probe implant site in a rat model of a FBR up to 6 days post implantation. Fluorescent bead-based immunoassays (Luminex) were used to quantify monocyte chemoattractant protein-1 (MCP-1/CCL2), interleukin-6 (IL-6) and interleukin-10 (IL-10) in the dialysates. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to cross validate the protein measurements obtained via micorodialysis sampling. A histological examination of tissue was also performed to assess the progression in leukocyte extravasation and collagen deposition surrounding implanted probes. Our findings demonstrate that in vivo microdialysis sampling can be used to collect temporal concentrations of cytokines which are consistent with wound healing and the development of a FBR.

7: Biochemical and biophysical research communications, 2010 Aug 19, 285(35)
Identification of BCAP-(L) as a negative regulator of the TLR signaling-induced production of IL-6 and IL-10 in macrophages by tyrosine phosphoproteomics.

[Abstract]Toll-like receptor (TLR) signaling in macrophages is essential for anti-pathogen responses such as cytokine production and antigen presentation. Although numerous reports suggest that protein tyrosine kinases (PTKs) are involved in cytokine induction in response to lipopolysaccharides (LPS; TLR4 ligand) in macrophages, the PTK-mediated signal transduction pathway has yet to be analyzed in detail. Here, we carried out a comprehensive and quantitative dynamic tyrosine phosphoproteomic analysis on the TLR4-mediated host defense system in RAW264.7 macrophages using stable isotope labeling by amino acids in cell culture (SILAC). We determined the temporal profiles of 25 proteins based on SILAC-encoded peptide(s). Of these, we focused on the tyrosine phosphorylation of B-cell adaptor for phosphatidylinositol 3-kinase (BCAP) because the function of BCAP remains unknown in TLR signaling in macrophages. Furthermore, Bcap has two distinct transcripts, a full-length (Bcap-(L)) and an alternatively initiated or spliced (Bcap-(S)) mRNA, and little is known about the differential functions of the BCAP-(L) and BCAP-(S) proteins. Our study showed, for the first time, that RNAi-mediated selective depletion of BCAP-(L) enhanced IL-6 and IL-10 production but not TNF-alpha production in TLR ligand-stimulated macrophages. We propose that BCAP-(L) (but not BCAP-(S)) is a negative regulator of the TLR-mediated host defense system in macrophages.

8: American journal of physiology. Lung cellular and molecular physiology, 2010 Aug 6, 247(2)
Glucocorticoids potentiate IL-6 induced SP-B expression in H441 cells by enhancing the Jak/Stat signaling pathway.

[Abstract]The respiratory distress syndrome (RDS) contributes to perinatal morbidity and mortality associated with preterm birth. Surfactant protein B (SP-B) is decreased in RDS. Both maternal antenatal steroid administration and chorioamnionitis reduce the incidence and severity of RDS. An important mediator in chorioamnionitis is interleukin-6 (IL-6) using the Jak-Stat signaling pathway for signaltransduction. We hypothesized that betamethasone (BTM) and dexamethasone (DEX) and IL-6 had synergistic effects on SP-B gene expression and Stat3 phosphorylation in H441 cells. DXM and BTM increased SP-B mRNA levels by 16.5 (13.3)-fold and IL-6 alone by 2.3-fold. After 48-hour exposure of cells to DXM or BTM, IL-6 caused a significantly greater increase in SP-B mRNA levels (28.1-fold) than IL-6 or glucocorticoids alone. While IL-6 stimulated tyrosine phosphorylation of Stat3 in a time- and dose dependent way, DXM and BTM had no effect on Stat3 phosphorylation. Both DXM and BTM could potentiate IL-6 induced phosphorylation of Stat3. The synergism of glucocorticoids and IL-6 on SP-B gene expression and the effect of glucocorticoids on IL-6 induced Stat3 phosphorylation could be blocked by a Jak-inhibitor. Expression level analysis showed that glucocorticoids increased the expression of the IL-6 binding alpha-subunit receptor (IL-6R) on mRNA and protein level. Our findings could represent an example of a pulmonary regulation-system in which one role of glucocorticoids is to increase the effect of a cytokine by up-regulation of its receptor. The described in vitro interaction of IL-6 and glucocorticoids could help explain the clinical observation that prenatal inflammation in preterm babies with antenatal steroid administration can attenuate severity of RDS.

9: Journal of perinatology : official journal of the California Perinatal Association, 2010 Jul 29, 76(2)
Comparable effect of conventional ventilation versus early high-frequency oscillation on serum CC16 and IL-6 levels in preterm neonates.

[Abstract]Objective:Clara cell 16 kD protein (CC16) and interleukin (IL)-6 have been used as peripheral blood biomarkers of alveolar leakage and inflammation, respectively. Thus, their measurement in the bloodstream could be used to assess ventilator-induced lung injury. The objective of this study was to evaluate the effect of optimized synchronized intermittent mandatory ventilation (SIMV) and high-frequency oscillatory ventilation (HFOV) on circulating CC16 and IL-6 levels when used as the initial ventilation modes in preterm neonates.Study Design:Single center, prospective, randomized clinical study in preterm neonates (gestational age 10: Trials, 2010 Jul 28, 11(1)
The effects of a muscle resistance program on the functional capacity, knee extensor muscle strength and plasma levels of IL-6 and TNF-alpha in pre-frail elderly women: a randomized crossover clinical trial - a study protocol.

[Abstract]ABSTRACT: BACKGROUND: With the increase in the elderly population, a growing number of chronic degenerative diseases and a greater dependency on caregivers have been observed. Elderly persons in states of frailty remain more susceptible to significant health complications. There is evidence of an inverse relationship between plasma levels of inflammatory mediators and levels of functionality and muscle strength, suggesting that muscle-strengthening measures can aid in inflammatory conditions. The purpose of this study will be verified the effect of a muscle-strengthening program with load during a ten-week period in pre-frail elderly women with attention to the following outcomes: (1) plasma levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha), (2) functional capacity and (3) knee extensor muscle strength. METHODS: The study design is a randomized crossover clinical trial evaluating 26 elderly women (regardless of their race and/or social condition) who are community residents, older than 65, and classified as pre-frail according to the criteria previously described by Fried et al. (2004). All subjects will be assessed using the Timed up and go and 10-Meter Walk Test functional tests. The plasma levels of IL-6 and TNF-alpha will be assessed by ELISA (enzyme-linked immunosorbent assay) with high sensitivity kits (QuantikineHS, R&D Systems Minneapolis, MN, U.S.). Knee extensor muscle strength will be assessed using the Byodex System 3 Pro isokinetic dynamometer at angular speeds of 60 and 1800/s. The intervention will consist of strengthening exercises of the lower extremities at 50 to 70% of 1RM (maximal resistance) three times per week for ten weeks. The volunteers will be randomized into two groups: group E, the intervention group, and group C, the control group that did not initiate any new activities during the initial study period (ten weeks). After the initial period, group C will begin the intervention and group E will maintain everyday activities without exercising. At the end of the total study period, all volunteers will be reassessed. DISCUSSION: To demonstrate and discuss possible influences of load-bearing exercises on the modification of plasma levels of IL-6 and TNF-alpha and in the functional performance of pre-frail elderly women. Trial Registration ISRCTN62824599.

11: Lasers in surgery and medicine, 2010 Aug, 42(6)
Single session to infrared low level diode laser on TNF-alpha and IL-6 cytokines release by mononuclear spleen cells in mice: A pilot study.

[Abstract]BACKGROUND AND OBJECTIVE: The results of low-level infrared laser (LLL) systemic action on inflammatory modulation process, specifically diminishing pro-inflammatory and producing anti-inflammatory cytokines are extremely controversial in the literature. More studies are necessary to clarify the biomodulation process. The main objective was to investigate the effect of a single session of an AsGaAl laser on spleen cells interleukin-6 (IL-6) and tumor necrosis factor - alpha (TNF-alpha) release, in vivo, in mice. STUDY DESIGN/MATERIALS AND METHODS: In a pilot study, 18 isogenic mice were distributed in three groups: control (no surgical procedure, n = 6), sham (surgical procedure with three standard cutaneous incisions, followed by abdominal muscle incision followed by suture, n = 6) and LLL (same procedure followed by a single LLL exposure 12 hours after the procedure, n = 6). The animals in the LLL group received a single infrared continuous laser session (780 nm wavelength, power of 20 mW, energy density of 10 J/cm(2)) on three points (20 seconds per point), and final energy of 0.4 J. All animals of the sham and LLL groups were sacrificed 36 hours after surgical procedure; the spleen mononuclear cells were isolated and cultivated for 48 hours. The IL-6 and TNF-alpha were measured by the ELISA method. RESULTS: IL-6 and TNF-alpha concentrations released by the mononuclear cells showed significant differences between the control and sham group (P < 0.07). However, there were no differences between the control and LLL group and between the sham and LLL groups (P > 0.07). CONCLUSION: The single session of infrared LLL showed a tendency of decreasing the IL-6 and TNF-alpha release by mononuclear spleen cells in mice after application, although there was not a significant difference between the sham and LLL group. Conclusions regarding effectiveness of a single session procedure cannot be made due to the low statistical power of this pilot study. Lasers Surg. Med. 42:584-588, 2010. (c) 2010 Wiley-Liss, Inc.

12: Rheumatology international, 2010 Jul 27, 11(1)
Plasma soluble IL-6 receptor concentration in rheumatoid arthritis: associations with the rs8192284 IL6R polymorphism and with disease activity.

[Abstract]Soluble interleukin-6 receptor alpha subunit (sIL-6R) is primarily generated by shedding of the membrane-bound form. This process is influenced by the single nucleotide polymorphism rs8192284 (A > C) resulting in an aspartic acid to alanine substitution (D358A) at the proteolytic cleavage site. The aim of this study was to determine whether plasma levels of sIL6R are influenced by the rs8192284 polymorphism in patients with rheumatoid arthritis and to assess the association between plasma sIL-6R levels and disease activity as reflected by anti-CCP status. Thirty-nine patients were randomly selected from a cohort of patients with RA of Spanish descent. Plasma sIL-6R concentrations were measured using sandwich ELISA. Genotyping of the rs8192284 (A > C) polymorphism was done using a Fast Real-Time PCR System. DAS 28 scores were used to assess disease activity. Plasma sIL-6R levels were positively associated with the number of C alleles (AA: 35.27 (3.50) ng/ml, AC: 45.50 (4.58) ng/ml, CC: 52.55 (3.18) ng/ml, P = 0.0001). DAS28 and plasma sIL-6R levels were positively associated in the anti-CCP-positive subgroup (r (2) = 0.45, P = 0.0336) and negatively associated in the anti-CCP-negative subgroup (r (2) = -0.45, P = 0.0825). No association between anti-CCP status and sIL-6R level was found. Our findings show that the rs8192284 polymorphism is operative in patients with RA. The presence of anti-CCP antibodies determines the relationship between sIL-6R concentration and disease activity.

13: Immunology and cell biology, 2010 Jul 27, 11(1)
The involvement of sphingosine kinase 1 in LPS-induced Toll-like receptor 4-mediated accumulation of HIF-1alpha protein, activation of ASK1 and production of the pro-inflammatory cytokine IL-6.

[Abstract]Toll-like receptors (TLRs) lie in the core of resistance to infectious diseases allowing host immune cells to specifically detect pathogens by recognising their specific molecular patterns. Cell membrane-associated TLR4 (recognises lipopolysaccharide (LPS) of Gram-negative bacteria) and endosomal TLR7/8 (recognise viral single-stranded RNA) are known to activate hypoxia inducible factor-1alpha (HIF-1alpha) protein (necessary for cellular adaptation to the inflammatory stress) via redox-dependent mechanism. TLR4 triggers the cross talk between HIF-1alpha and apoptosis signal-regulating kinase 1 (ASK1), whereas TLR7/8 activates HIF-1alpha in the ASK1-independent manner. Here, we report that in THP-1 and RAW264.7 macrophages, ligand-induced activation of the TLR4 but not TLR7/8 induces activation and transcriptional upregulation of sphingosine kinase 1 (SphK1) in extracellular signal-regulating kinase and phospholipase C-1gamma/PI3 kinase-dependent manner. TLR4-mediated SphK1 activation was found to be critical for the redox-dependent activation of HIF-1alpha and ASK1, as well as for the prevention of LPS-induced activation of caspase 3 and the expression of pro-inflammatory cytokine interleukin-6.Immunology and Cell Biology advance online publication, 27 July 2010; doi:10.1038/icb.2010.91.

14: Rheumatology international, 2010 Jul 24, 49(8)
IL-6 blockade preferentially inhibits Th17 differentiation in collagen-induced arthritis.

[Abstract]We examined the time course of cytokine production by CD4 T cells from mice with collagen-induced arthritis (CIA), and we determined the influence of interleukin-6 (IL-6) blockade on cytokine production. CD4 T cells purified from spleen were cultured with both collagen and anti-CD28 antibody for 48 h and the production of interferon-gamma (IFN-gamma), IL-4, and IL-17 by the cells, secreted into the supernatants, was measured at various time intervals. The production of all these cytokines started 7 days after the first immunization. A marked increase in IFN-gamma production was observed after the second immunization, but IL-4 and IL-17 production was not affected by a second immunization. A single injection of anti-mouse IL-6 receptor antibody (MR16-1) on the day of the first immunization suppressed the onset of arthritis. IL-17 production by CD4 T cells from MR16-1-treated mice was significantly lower than that from the control mice. On the other hand, treatment with MR16-1 showed only a tendency to suppress the production of IL-4 and IFN-gamma. Injection of MR16-1 on day 21 did not suppress the onset of arthritis. We examined the direct influence of MR16-1 on cytokine production by differentiated CD4 T cells from arthritic mice. Production of IL-4, IFN-gamma, and IL-17 was not affected by MR16-1. In conclusion, IL-6 inhibition preferentially suppresses the induction of Th17 cells and does not seem to impact on cytokine production of already differentiated Th17 cells.

15: American journal of physiology. Lung cellular and molecular physiology, 2010 Jul 23, 49(8)
Extracellular Acidification Stimulates IL-6 Production and Ca2+ Mobilization Through Proton-Sensing OGR1 Receptors In Human Airway Smooth Muscle Cells.

[Abstract]The asthmatic airway has been shown to be an acidic environment which may be involved in the pathophysiological features of asthma. However, the mechanism by which an acidic pH modulates the cellular activities involved in the asthmatic airway remains elusive. Here, we characterized acidic pH-induced actions in human airway smooth muscle cells (ASMCs). Extracellular acidification stimulates the mRNA expression and protein production of interleukin (IL)-6, a pro-inflammatory cytokine, in association with the phosphorylation of extracellular signal-regulated kinase (ERK) and p38MAPK, reflecting the activation of the enzymes. Acidification-induced cytokine production was inhibited by inhibitors of ERK and p38MAPK. Acidification also increased intracellular Ca(2+) concentration, which was accompanied by cell rounding, most likely reflecting contraction. In ASMCs, OGR1 is expressed at by far the highest levels among proton-sensing G-protein-coupled receptors. The knockdown of OGR1 and G(q/11)-protein with their specific small interfering RNAs and an inhibition of G(q/11)-protein with YM-254890 attenuated the acidification-induced actions. We conclude that extracellular acidification stimulates IL-6 production and Ca(2+) mobilization through proton-sensing OGR1 receptors/G(q/11)-proteins in human ASMCs.

16: Diabetologia, 2010 Jul 24, 49(8)
AMP-activated protein kinase inhibits IL-6-stimulated inflammatory response in human liver cells by suppressing phosphorylation of signal transducer and activator of transcription 3 (STAT3).

[Abstract]AIM/HYPOTHESIS: The aim of the study was to examine the possible role of AMP-activated protein kinase (AMPK) in the regulation of the inflammatory response induced by cytokine action in human liver cells. METHODS: IL-6-stimulated expression of the genes for acute-phase response markers serum amyloid A (SAA1, SAA2) and haptoglobin (HP) in the human hepatocarcinoma cell line HepG2 were quantified after modulation of AMPK activity by pharmacological agonists (5-amino-4-imidazole-carboxamideriboside [AICAR], metformin) or by using small interfering (si) RNA transfection. The intracellular signalling pathway mediating the effect of AMPK on IL-6-stimulated acute-phase marker expression was characterised by assessing the phosphorylation levels of the candidate protein signal transducer and activator of transcription 3 (STAT3) in response to AMPK agonists. RESULTS: AICAR and metformin markedly blunt the IL-6-stimulated expression of SAA cluster genes as well as of haptoglobin in a dose-dependent manner. Moreover, the repression of AMPK activity by siRNA significantly reversed the inhibition of SAA expression by both AICAR and metformin, indicating that the effect of the agonists is dependent on AMPK. For the first time we show that AMPK appears to regulate IL-6 signalling by directly inhibiting the activation of the main downstream target of IL-6, STAT3. CONCLUSIONS/INTERPRETATION: We provide evidence for a key function of AMPK in suppression of the acute-phase response caused by the action of IL-6 in liver, suggesting that AMPK may act as an intracellular link between chronic low-grade inflammation and metabolic regulation in peripheral metabolic tissues.

17: Cytokine, 2010 Jul 17, 49(8)
IL-6 increases airway resistance in the rat.

[Abstract]The end-inspiratory occlusion method was applied in anesthetized, paralyzed, positive pressure-ventilated rats to assess the possible effects of interleukin IL-6 on respiratory mechanics in normal rats. Measurements were made in control rats and in experimental animals before and after IL-6 intraperitoneal administration (15ng/100g), including static respiratory system elastance, the resistance to airflow and to the movement of respiratory system tissues, and the resistance due to lung stress-relaxation and mechanical inhomogeneity. Respiratory system hysteresis was also measured, and total mechanical breathing work rate and its elastic and resistive components calculated. Control rats did not exhibit alteration in respiratory mechanics during the observation period (30min), while the experimental animals showed an increase in resistive pressure dissipations starting 15min after IL-6 administration. Dose-dependent effects were also investigated. In a rather delayed effect, IL-6 increased the resistance to airflow and to the movement of respiratory system tissues, the resistance due to lung stress-relaxation and mechanical inhomogeneity, and the related resistive mechanical breathing work rate, and left the elastic pressure dissipation unaltered. The mechanisms by which IL-6 may contribute to the airways resistance increase which is seen in different respiratory diseases are likewise discussed.

18: Pain, 2010 Jul 16, 49(8)
A new utensil in our toolbox: Exploring the role of IL-6 in pain using a naturally occurring antagonist.

[Abstract]The end-inspiratory occlusion method was applied in anesthetized, paralyzed, positive pressure-ventilated rats to assess the possible effects of interleukin IL-6 on respiratory mechanics in normal rats. Measurements were made in control rats and in experimental animals before and after IL-6 intraperitoneal administration (15ng/100g), including static respiratory system elastance, the resistance to airflow and to the movement of respiratory system tissues, and the resistance due to lung stress-relaxation and mechanical inhomogeneity. Respiratory system hysteresis was also measured, and total mechanical breathing work rate and its elastic and resistive components calculated. Control rats did not exhibit alteration in respiratory mechanics during the observation period (30min), while the experimental animals showed an increase in resistive pressure dissipations starting 15min after IL-6 administration. Dose-dependent effects were also investigated. In a rather delayed effect, IL-6 increased the resistance to airflow and to the movement of respiratory system tissues, the resistance due to lung stress-relaxation and mechanical inhomogeneity, and the related resistive mechanical breathing work rate, and left the elastic pressure dissipation unaltered. The mechanisms by which IL-6 may contribute to the airways resistance increase which is seen in different respiratory diseases are likewise discussed.

19: Journal of endocrinological investigation, 2010 Jul 13, 49(8)
Effect of recombinant growth hormone on leptin, adiponectin, resistin, IL-6, TNF-alpha and ghrelin levels in growth hormone deficient children.

[Abstract]Background: Treatment with growth hormone (GH) promotes linear growth and decreases body fat in patients with isolated GH deficiency (GHD). However, few studies have analyzed how GH replacement modifies ghrelin levels and the adipokine profile and the relationship of these modifications with the metabolic changes. Aims: To analyze the eventual differences between serum levels of leptin, leptin soluble receptor (sOBR), resistin, adiponectin, IL-6, TNF-alpha total (TG) and acylated ghrelin (AG) and lipid and glycemic profiles in children with GHD, as well as to determine the effect of GH replacement on these parameters during the first year of therapy. Subjects and methods: Thirty prepubertal (Tanner stage I) GHD children and 30 matched controls were enrolled. Children with GHD were studied before and after 6 and 12 months of GH treatment. Weight, height, BMI, fasting glucose, insulin, lipid profile and serum levels of adipokines and ghrelin were studied at every visit. Adipokines, insulin and ghrelin levels were determined by using commercial radio- and enzymoimmunoassays. Results: At baseline children with GHD had significantly higher sOBR (p<0.01) and adiponectin (p<0.01) levels than controls. Treatment with GH resulted in a decline in leptin (p<0.05) and TG (p<0.001) levels, an increase of HOMA index and restored IGF-I levels (p<0.001). Conclusions: These data indicate that GH replacement has a negative effect on leptin levels and may also produce a slight unfavorable effect on carbohydrate metabolism. In addition, the changes observed in the adipokine profile appear to be independent of BMI.

20: Pediatric nephrology (Berlin, Germany), 2010 Jul 15, 49(8)
The IL-6 -174G/C polymorphism and renal scarring in children with first acute pyelonephritis.

[Abstract]Urinary tract infections (UTI) are common in infants and children and may result in serious complications, such as renal scarring, hypertension, and renal failure. Identification of the new markers in relation to acute pyelonephritis (APN) and its treatment is essential for designing interventions that would minimize tissue damage. This prospective study investigated the first UTI infection in 71 children (age range: 1-24 months) in respect to interleukin-6 (IL-6) -174G/C polymorphism and renal scarring. The patients were divided into an APN group and a lower UTI group according to dimercaptosuccinic acid (DMSA). The IL-6 -174G/C genotypes were determined by tetra-primer ARMSPCR. Serum IL-6 was significantly higher in the APN group than in the group with lower UTI (p < 0.05). In both groups, the -174G/C genotype and allele frequencies did not differ significantly from the control group. The highest white blood cell (WBC) count was observed in the CC genotype (p < 0.05). A non-significant trend toward higher serum IL-6 was observed in children with CC genotype. On follow-up DMSA imaging performed 6 months later, renal scarring was detected in 36.9% of APN children. We did not find the significant association of IL-6 -174G/C polymorphism with APN and/or postinfectious renal scarring. These results indicate that serum IL-6 concentrations were significantly higher in children with APN than in patients with lower UTI.

21: The Journal of investigative dermatology, 2010 Jul 15, 49(8)
Overexpression of LEDGF/DFS70 Induces IL-6 via p38 Activation in HaCaT Cells, Similar to that Seen in the Psoriatic Condition.

[Abstract]Lens epithelium-derived growth factor (LEDGF)/dense fine speckles 70 kDa protein (DFS70) is a transcription cofactor that enhances growth and is overexpressed in various cancers. In the epidermis, LEDGF/DFS70 localizes to the nucleus of keratinocytes (KCs) in the basal layers and to the cytoplasm of cells in the upper layers. However, the biological and pathological relevance of LEDGF/DFS70 in the epidermis is virtually unknown. Compared with normal epidermis, we detected strong nuclear staining of LEDGF/DFS70 in both the spinous and basal layers of the epidermis of psoriatic skin. To investigate the roles of LEDGF/DFS70 in the epidermis of psoriatic skin, we generated HaCaT cells that constitutively express enhanced green fluorescence protein (EGFP)-LEDGF (EGFP-LEDGF-HaCaT) or EGFP alone (EGFP-HaCaT) as a control. EGFP-LEDGF-HaCaT cells had increased expression of IL-6, which was attenuated by LEDGF-specific RNA interference and the p38-specific inhibitors SB-239063 and SB-203580. Furthermore, EGFP-LEDGF-HaCaT cells had increased expression of S100A7 and S100A9 and decreased expression of filaggrin. These findings are compatible with the expression pattern in psoriatic tissues. Taken together, these results strongly suggest that ectopic expression of LEDGF/DFS70 in KCs could be involved in the pathology of psoriasis vulgaris.Journal of Investigative Dermatology advance online publication, 15 July 2010; doi:10.1038/jid.2010.203.

22: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2010 Jul 14, 49(8)
Serum IL-6, albumin and co-morbidities are closely correlated with symptoms of depression in patients on maintenance haemodialysis.

[Abstract]BACKGROUND: Depression may be associated with activation of pro-inflammatory cytokines and increased long-term mortality in patients on maintenance haemodialysis (MHD). There are numerous reports regarding the association of depression with inflammatory status, co-morbidities and nutritional condition, but few of these studies have explored the possible correlations between depression, age and economic status. The study explores the possible correlations between depression and demographic, socio-economic, clinical and laboratory variables. METHODS: One hundred and forty-six MHD patients (65 males and 81 females, mean age: 63.8 +/- 15.2 years) were enrolled in this cross-sectional study. Demographic and socio-economic status as well as clinical and laboratory variables including co-morbidities were obtained. The self-administered Beck Depression Inventory (BDI) was used to determine the presence or absence of depression symptoms. Biochemical parameters (serum albumin, triglyceride, cholesterol, etc.) and dialysis dosage delivery (Kt/V and urea reduction rate or URR) were examined. All the patients were on high-flux biocompatible dialysers for MHD. The presence of an inflammatory state was assessed by determinations of plasma interleukin-6 (IL-6) levels. RESULTS: The prevalence of depression (BDI >/=14) was 45.9%. In patients found to have symptoms of depression, no statistically significant difference was shown with respect to age, gender, smoking habits or clinical characteristics. However, these patients were more likely to have a number of co-morbidities. They also had higher levels of serum IL-6 and total cholesterol as well as lower serum albumin and Kt/V values. The BDI correlated significantly with Kt/V values (r = -0.19; P < 0.05), levels of serum albumin (r = -0.28; P < 0.005) and serum IL-6 (r = 0.47; P < 0.001). Multivariate stepwise forward logistic regression analysis showed a direct correlation between BDI and IL-6 levels (P = 0.001; OR = 1.537) and between BDI and co-morbidities (P = 0.037; OR = 3.584). There was an inverse correlation between BDI and serum albumin levels (P = 0.006; OR = 0.145) and between BDI and age (P = 0.007; OR = 0.96). The rate of depression was significantly lower for the elderly patients (age >/=75 years) compared with those below 64 years of age. The percentage of personal monthly disposable income at or above Taiwan dollar (TWD) >10 000 was similar in patients aged >/=75 and those below 64 years old. CONCLUSIONS: Maintenance haemodialysis patients with symptoms of depression may have higher serum IL-6 and lower serum albumin levels. The prevalence of depression was lower in elderly patients at or above 75 years old, and no correlation was found with socio-economic status. Factors including co-morbid conditions, serum IL-6, albumin and age may help predict which patients may be predisposed to develop symptoms of depression.

23: Biochemical and biophysical research communications, 2010 Jul 2, 397(3)
TNF-alpha similarly induces IL-6 and MCP-1 in fibroblasts from colorectal liver metastases and normal liver fibroblasts.

[Abstract]Cancer-associated fibroblasts (CAFs) represent the predominant cell type of the neoplastic stroma of solid tumors, yet their biology and functional specificity for cancer pathogenesis remain unclear. We show here that primary CAFs from colorectal liver metastases express several inflammatory, tumor-enhancing factors, including interleukin (IL)-6 and monocyte-chemoattractant protein (MCP)-1. Both molecules were intensely induced by TNF-alpha on the transcript and protein level, whereas PDGF-BB, TGF-beta1 and EGF showed no significant effects. To verify their potential specialization for metastasis progression, CAFs were compared to fibroblasts from non-tumor liver tissue. Interestingly, these liver fibroblasts (LFs) displayed similar functions. Further analyses revealed a comparable up-regulation of intercellular adhesion molecule-1 (ICAM-1) by TNF-alpha, and of alpha-smooth muscle actin, by TGF-beta1. Moreover, the proliferation of both cell types was induced by PDGF-BB, and CAFs and LFs displayed an equivalent migration towards HT29 colon cancer cells in Boyden chamber assays. In conclusion, colorectal liver metastasis may be supported by CAFs and resident fibroblastic cells competent to generate a prometastatic microenvironment through inflammatory activation of IL-6 and MCP-1.

24: Journal of leukocyte biology, 2010 Jul 7, 53(8)
More than a sidekick: the IL-6 family cytokine IL-11 links inflammation to cancer.

[Abstract]IL-11, a member of the IL-6 family of cytokines, exerts pleiotropic activities by stimulating hemopoiesis and thrombopoiesis, regulating macrophage differentiation, and conferring mucosal protection in the intestine. These effects are mediated by a multimeric complex comprising the ligand-binding IL-11Ralpha and the ubiquitously expressed gp130R beta-subunit, which together, trigger intracellular signaling and engagement of Stat3. In turn, activated Stat3 promotes cell survival and proliferation as well as immune responses associated with inflammatory diseases and tumor progression. IL-6 and IL-11 compete for interaction with gp130, resulting in tissue-specific functions depending on the expression patterns of their respective alpha-subunit receptors. Although traditionally, IL-6 has been associated with aberrant Stat3 activation and associated pathologies, here, we discuss newly emerging roles for IL-11 in linking inflammation to cancer progression. We propose that in light of the recurrence of persistent STAT3 activation and elevated IL-11 expression in inflammation-associated gastrointestinal cancers in humans, inhibition of Stat3 or pharmacologically, more amenable upstream molecules such as IL-11 may represent novel, therapeutic targets.

25: Journal of immunology (Baltimore, Md. : 1950), 2010 Jul 7, 53(8)
TNF, but Not IL-6 and IL-17, Is Crucial for the Development of T Cell-Independent Psoriasis-Like Dermatitis in Il1rn-/- Mice.

[Abstract]IL-1 is a proinflammatory cytokine consisting of two molecular species, IL-1alpha and IL-1beta, and IL-1R antagonist (gene: Il1rn) is the endogenous suppressor. Il1rn(-/-) mice spontaneously develop autoimmune diseases, such as arthritis and aortitis, and a dermatitis that histologically resembles human psoriasis. The pathogenic mechanisms underlying this dermatitis, however, remain to be elucidated. In this study, we demonstrated that the production of inflammatory cytokines and chemokines was enhanced at the site of inflammation. The development of dermatitis was completely suppressed in Tnfsf1a(-/-) but not in Il6(-/-) mice, similar to that observed in arthritis and aortitis. However, IL-17 deficiency did not affect the development of dermatitis at all, in clear contrast to that of arthritis and aortitis. Different from arthritis and aortitis, adoptive transfer of Il1rn(-/-) T cells did not induce dermatitis in the recipient SCID mice and skin lesions developed in Il1rn(-/-) SCID mice, indicating that T cells are not involved in the development of skin lesions. In support for this, bone marrow cell transplantation experiments showed that TNF produced by skin residential cells, but not bone marrow cell-derived cells, was important for the development of dermatitis. Furthermore, we showed that IL-1 directly enhanced TNF and chemokine expression in keratinocytes. These observations suggest that excess IL-1 signaling directly activates keratinocytes to produce TNF and chemokines, resulting in the development of psoriasis-like skin lesions without the involvement of autoimmunity in Il1rn(-/-) mice.

26: Journal of cellular physiology, 2010 Jul 6, 53(8)
TGFbeta1 induces IL-6 and inhibits IL-8 release in human bronchial epithelial cells-the role of SMAD2/3.

[Abstract]Human bronchial epithelial (HBE) cells contribute to asthmatic airway inflammation by secreting cytokines, chemokines and growth factors, including interleukin (IL)-6, IL-8 and transforming growth factor (TGF) beta1, all of which are elevated in asthmatic airways. This study examines the signaling pathways leading to TGFbeta1 induced IL-6 and IL-8 in primary HBE cells from asthmatic and non-asthmatic volunteers. HBE cells were stimulated with TGFbeta1 in the presence or absence of signaling inhibitors. IL-6 and IL-8 protein and mRNA were measured by ELISA and real-time PCR respectively, and cell signaling kinases by western blot. TGFbeta1 increased IL-6, but inhibited IL-8 production in both asthmatic and non-asthmatic cells; however TGF induced significantly more IL-6 in asthmatic cells. Inhibition of JNK MAP kinase partially reduced TGFbeta1 induced IL-6 in both cell groups. TGFbeta1 induced Smad2 phosphorylation, and blockade of Smad2/3 prevented both the TGFbeta1 modulated IL-6 increase and the decrease in IL-8 production in asthmatic and non-asthmatic cells. Inhibition of Smad2/3 also increased basal IL-8 release in asthmatic cells but not in non-asthmatic cells. Using CHIP assays we demonstrated that activated Smad2 bound to the IL-6, but not the IL-8 promoter region. We conclude that the Smad2/3 pathway is the predominant TGFbeta1 signaling pathway in HBE cells, and this is altered in asthmatic bronchial epithelial cells. Understanding the mechanism of aberrant pro-inflammatory cytokine production in asthmatic airways will allow the development of alternative ways to control airway inflammation. (c) 2010 Wiley-Liss, Inc.

27: Cellular and molecular neurobiology, 2010 Jul 6, 53(8)
Repeated Stress Down-Regulates beta(2)- and alpha (2C)-Adrenergic Receptors and Up-Regulates Gene Expression of IL-6 in the Rat Spleen.

[Abstract]Catecholamines are among first compounds released during stress, and they regulate many functions of the organism, including immune system, via adrenergic receptors (ARs). Spleen, as an immune organ with high number of macrophages, possesses various ARs, from which beta(2)-ARs are considered to be the most important for the modulation of immune functions. Nevertheless, little is known about the regulation and involvement of ARs in the splenic function by stress. Therefore, the aim of this work was to measure the gene expression of ARs and several cytokines in the spleen of rats exposed to a single and repeated (14x) immobilization stress (IMO). We have found a significant increase in beta(2)-AR mRNA after a single IMO, but a significant decrease in beta(2)-AR mRNA and protein level after repeated (14x) IMO. The most prominent decrease was detected in the gene expression of the alpha(2A)- and alpha(2C)-AR after repeated IMO. However, changes in mRNA were translated into protein levels only for the alpha(2C)-subtype. Other types of ARs remained unchanged during the stress situation. Since we proposed that these ARs might affect production of cytokines, we measured gene expression of pro-inflammatory (TNF-alpha, IL-1beta, IL-6 and IL-18) and anti-inflammatory (IL-10 and TGF-beta1) cytokines. We detected changes only in IL-6 and IL-10 mRNA levels. While IL-6 mRNA was increased, IL-10 mRNA dropped after repeated IMO. According to these results we suggest that changes of beta(2)- and alpha(2C)-ARs participate in IL-6-mediated processes in the spleen, especially during chronic stress situations.

28: Emergency medicine journal : EMJ, 2010 Jul 1, 55(7)
Serum IL-6, TNF{alpha} levels in snakebite cases occurring in Southern Turkey.

[Abstract]Objective The snake species Vipera ammodytes meridionalis and Vipera lebetina obtuse are often seen in Southern Turkey and have venom that causes serious systemic and tissue damage. The aim of our study is to assess the relationship between tumour necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6) serum levels, and clinical and laboratory findings in the snakebite patients. Methods 26 patients who had received snakebites were included in a prospective study. Patients were grouped according to their clinical presentations in order to plan treatment. Results TNFalpha serum levels of most patients who went to the emergency room to receive treatment for snakebite were high. This increase was most likely to be related to the clinical severity of the snakebite and the length of time between the snakebite and their arrival at the hospital. In contrast to TNFalpha, there was no relationship between serum IL-6 levels and clinical and laboratory parameters. Conclusions Snakebites from Vipera ammodytes meridionalis and Vipera lebetina obtuse lead to increased levels of serum TNFalpha. However, serum TNFalpha and IL-6 levels depend on various factors such as the kind of snake, the area the venom was injected into, the amount of venom and the body size of the patients.

29: Immunopharmacology and immunotoxicology, 2010 Jun 30, 70(4)
Inhibitory effects of the transgenic Panax ginsengs on phorbol ester plus A23187-induced IL-6 production and cyclooxygenase-2 via suppression of NF-kappaB and MAPKs in HMC-1.

[Abstract]Our previous studies have that demonstrated the overexpression of the squalene synthase gene enhances the biosynthesis of triterpene and phytosterol in Panax ginseng. The total ginsenoside contents in adventitious roots of transgenic P. ginseng were about 1.6-3-fold higher than those in the wild-type. In the present work, we have evaluated the anti-inflammatory effects of two types of transgenic P. ginseng (BS and SS) and the wild-type P. ginseng (GS) in a stimulated human mast cell line 1 (HMC-1). GS, BS, and SS inhibited not only the production of interleukin 6 (IL-6), but also the expression of cyclooxygenase-2 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (PMACI)-stimulated HMC-1. Additionally, GS, BS, and SS suppressed the expression of the nuclear transcription factor kappaB and mitogen-activated protein kinases induced by PMACI. The anti-inflammatory effects of BS and SS were higher than that of GS. These results provide new insights into the pharmacological actions of transgenic P. ginseng as a potential molecule for use in therapy in mast cell-mediated inflammatory diseases.

30: European journal of immunology, 2010 Jun 25, 40(7)
IL-6: Regulator of Treg/Th17 balance.

[Abstract]IL-6 is a pleiotropic cytokine involved in the physiology of virtually every organ system. Recent studies have demonstrated that IL-6 has a very important role in regulating the balance between IL-17-producing Th17 cells and regulatory T cells (Treg). The two T-cell subsets play prominent roles in immune functions: Th17 cell is a key player in the pathogenesis of autoimmune diseases and protection against bacterial infections, while Treg functions to restrain excessive effector T-cell responses. IL-6 induces the development of Th17 cells from na?ve T cells together with TGF-beta; in contrast, IL-6 inhibits TGF-beta-induced Treg differentiation. Dysregulation or overproduction of IL-6 leads to autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA), in which Th17 cells are considered to be the primary cause of pathology. Given the critical role of IL-6 in altering the balance between Treg and Th17 cells, controlling IL-6 activities is potentially an effective approach in the treatment of various autoimmune and inflammatory diseases. Here, we review the role of IL-6 in regulating Th17/Treg balance and describe the critical functions of IL-6 and Th17 in immunity and immune-pathology.

31: European journal of applied physiology, 2010 Jun 24, 40(7)
The reliability of the IL-6, sIL-6R and sgp130 response to a preloaded time trial.

[Abstract]Interleukin-6 (IL-6) is a cytokine that can mediate numerous biological actions including fatigue. Circulating IL-6 increases during prolonged exercise, and furthermore, the signalling receptors sIL-6R and sgp130 are also increased. The variability of the response of these markers to exercise is unknown; therefore, we examined the changes in these markers to a preloaded time trial bout of running. Nine males performed three identical trials where participants ran at 60% [Formula: see text] for 2 h interspersed with 30 s at 90% [Formula: see text] every 10 min, followed by a 5-km time trial. Blood samples were drawn at baseline, following the 2-h bout, post time trial, 1 h post time trial and the following morning. Results showed that between-subject variability (CVg) was greater than within-subject variation (CVi) for the three markers. IL-6, sIL-6R and sgp130 demonstrated a CVi of 15.3-25.5%, 15.0-17.6% and 6.2-9.4% variation, respectively, across the time points. When the data from the second and third trials were analysed independently, CVi was reduced which is supported by the time trial results for which CVi improve (4.7-2.4%). In conclusion, the results indicate that a large variation in response to exercise can be reduced following a habituation trial.

32: Clinical oral investigations, 2010 Jun 19, 70(4)
Salivary IL-6 levels in oral leukoplakia with dysplasia and its clinical relevance to tobacco habits and periodontitis.

[Abstract]The development of oral cancer proceeds through discrete molecular changes that are acquired from loss of genomic integrity after continued exposure to environmental risk factors. It is preceded in the majority of cases by clinically evident oral potentially malignant disorders, the most common of which is leukoplakia. Early detection of these oral lesions by screening methods using suitable markers is critical as it mirrors molecular alterations, long before cancer phenotypes are manifested. Assessment of salivary interleukin-6 (IL-6) as a marker of malignant progression was undertaken in patients with leukoplakia having coexisting periodontitis (n = 20), periodontitis patients without leukoplakia (n = 20), and healthy controls (n = 20) by competitive enzyme-linked immunosorbent assay. Results showed elevation of IL-6 levels in leukoplakia with coexisting periodontitis and in periodontitis patients when compared to healthy control (P < 0.001). Within the leukoplakia group, IL-6 level was found to be increased with increase in the severity of dysplasia. The use of tobacco was seen to play a significant role in the elevation of salivary IL-6.The importance of IL-6 as a specific marker for leukoplakia with dysplasia and the role of tobacco as an independent risk factor has been highlighted.

33: The Journal of biological chemistry, 2010 Jun 18, 70(4)
Inhibition of STAT3 signaling blocks the anti-apoptotic activity of IL-6 in human liver cancer cells.

[Abstract]Interleukin-6 (IL-6) is a multifunctional cyto- kine, which may block apoptosis during inflammation to protect cells under very toxic conditions. However, IL-6 also activates STAT3 in many types of human cancer. Recent studies demonstrate that high levels of IL-6 are associated with hepatocellular carcinoma, the most common type of liver cancer. Here we reported that IL-6 promoted survival of human liver cancer cells through activating STAT3 in response to doxorubicin treatment. Endogenous IL-6 levels in SNU-449 cells were higher than in Hep3B cells. Meanwhile, SNU-449 cells were more resistant to doxorubicin than Hep3B cells. Addition of IL-6 induced STAT3 activation in Hep3B cells and led to protection against doxorubicin. In contrast, neutralizing IL-6 with anti-IL-6 antibody decreased survival of SNU-449 cells in response to doxorubicin. To elucidate the mechanism of the anti-apoptotic function of IL-6, we investigated if STAT3 mediated this drug resistance. Targeting STAT3 with STAT3 siRNA reduced the protection of IL-6 against doxorubicin-induced apoptosis, indicating that STAT3 signaling contributed to the anti-apoptotic effect of IL-6. Moreover, we further explored if a STAT3 small-molecule inhibitor could abolish this anti-apoptotic effect. LLL12, a STAT3 small-molecule inhibitor, blocked IL-6-induced STAT3 phosphorylation, resulting in attenuation of the anti-apoptotic activity of IL-6. Finally, neutralization of endogenous IL-6 with anti-IL-6 antibody or blockade of STAT3 with LLL12 lowered the recovery in SNU-449 cells after doxorubicin treatment. Therefore, our results demonstrated that targeting STAT3 signaling could interrupt the anti-apoptotic function of IL-6 in human liver cancer cells.

34: The Journal of biological chemistry, 2010 May 28, 71(6)
Mechanistic insights into the events that lead to synergistic induction of IL6 transcription upon activation of the Ah receptor and inflammatory signaling.

[Abstract]The aryl hydrocarbon receptor (AHR) is the ligand-activated transcription factor responsible for mediating the toxicological effects of dioxin and xenobiotic metabolism. However, recent evidence has implicated the AHR in additional, non-metabolic physiological processes, including immune regulation. Certain tumor cells are largely non-responsive to cytokine-mediated induction of the pro-survival cytokine IL6. We have demonstrated that multiple non-responsive tumor lines are able to undergo synergistic induction of IL6 following combinatorial treatment with IL1beta and the AHR agonist TCDD. Such data implicates the AHR in tumor expansion, although the mechanistic basis for the AHR-dependent synergistic induction of IL6 has not been determined. Here, we demonstrate that ligand-activated AHR is involved in priming the IL6 promoter through binding to non-consensus dioxin response elements (DREs) located upstream of the IL6 start site. Such binding appears to render the promoter more permissive to IL1beta-induced binding of NF-kappaB components. The nature of the AHR-dependent increases in IL6 promoter transcriptional potential has been shown to involve a reorganization of repressive complexes as exemplified by the presence of HDAC1 and HDAC3. Dismissal of these HDACs correlates with post-translational modifications of promoter-bound NF-kappaB components in a time dependent manner. Thus, the AHR plays a role in de-repressing the IL6 promoter, leading to synergistic IL6 expression in the presence of inflammatory signals. These observations may explain the association between enhanced expression of AHR and tumor aggressiveness. It is likely that AHR-mediated priming is not restricted to the IL6 promoter and may contribute to the expression of a variety of genes, which do not have consensus DREs.

35: Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K, 2010 May 27, 71(6)
CD44-ligation induces, through ERK1/2 pathway, synthesis of cytokines TNF-alpha and IL-6 required for differentiation of THP-1 monoblastic leukemia cells.

[Abstract]PURPOSE: The production of epithelial neutrophil activating peptide-78 (NA-78) and the interleukins IL-8 and IL-6 by endometrial stromal cells is stimulated by pro-inflammatory interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha). IL-8 is suggested to play a role in the pathogenesis of endometriosis, and in these women the peritoneal fluid concentrations of ENA-78 and IL-8 are increased. TNF-alpha has been tested together with interferon-gamma because of their cooperative stimulation of IL-6. The release of IL-8, however, is inhibited with increasing interferon levels. The aim of the study was the analysis of the production of ENA-78, IL-6 and IL-8 by cultured human endometrial stromal cells in the presence of varying concentrations of IL-1beta, TNF-alpha, and interferon-gamma. METHODS: Eutopic endometrial tissue was obtained from seven cycling, endometriosis-free women undergoing laparoscopy for reasons of infertility or pain. The release of ENA-78, IL-8 and IL-6 by the isolated and monolayer cultured stromal cell fraction in the presence of IL-1beta (0.08 to 50 ng/mL), TNF-alpha, and interferon-gamma (both 20 to 500 ng/mL) was determined. RESULTS: IL-1beta stimulated the production of IL-8, IL-6, and ENA-78 dose dependently from 0.08 to 2.0 ng/mL (ENA-78) or to 10 ng/mL (IL-8, IL-6); at 50 ng/mL a decrease in release was observed for IL-8 and IL-6. TNF-alpha stimulation yielded a plateau between 20 and 100 ng/mL. Interferon-gamma stimulated IL-6 and inhibited IL-8 production above 20 ng/mL. ENA-78 release was largely unaffected by interferon-gamma. CONCLUSIONS: IL-1beta and TNF-alpha stimulate stromal cytokine production cumulatively with different dose-response curves. The presence of interferon-gamma has opposite effects on IL-8 and IL-6. TNF-alpha and interferon-gamma should be investigated separately in future in vitro studies with endometrial cells and explants.

36: Journal of dental research, 2010 May 26, 71(6)
Stimulation of IL-6 Cytokines in Fibroblasts by Toll-like Receptors 2.

[Abstract]The osteotropic interleukin-6 (IL-6) types of cytokines IL-6, IL-11, and leukemia inhibitory factor (LIF), but not oncostatin M, are expressed by human gingival fibroblasts, and their expressions are regulated by IL-1 and tumor necrosis factor-alpha (TNF-alpha). In the present study, we investigated whether signaling through Toll-like receptor 2 (TLR2) can affect the expression of these cytokines in human gingival fibroblasts. Lipopolysaccharide (LPS) from P. gingivalis was found to stimulate IL-6 and LIF mRNA and protein, but not IL-11 or OSM mRNA. Using two synthetic ligands acting specifically at TLR2 and siRNA knockdown of TLR2, we demonstrated the important role of TLR2 in the stimulation of IL-6 and LIF in gingival fibroblasts. Analysis of these data suggests that signaling through the innate immune system controls the expression of osteotropic cytokines in human gingival fibroblasts.

37: Acta diabetologica, 2010 May 21, 634(1-3)
The predictive value of TNF-alpha and IL-6 and the incidence of macrovascular complications in patients with type 2 diabetes.

[Abstract]Some inflammation factors have been shown to accelerate type 2 diabetes macrovascular complication (T2DMC). The study investigates the variation of TNF-alpha and IL-6 levels during the progression of T2DMC to explore their predictive value in the incidence of T2DMC. All participants were divided into two groups, type 2 diabetes mellitus (T2DM) and non-diabetes (ND) group. TNF-alpha and IL-6 were analyzed with enzyme immunoassay. All participants were followed up by carotid Doppler, Doppler of lower extremities, head CT and 64-row multislice spiral CTA. The incidence of macrovascular atherosclerosis in T2DM was significantly higher than that in ND group (P < 0.05). The levels of TNF-alpha and IL-6 in both groups with atherosclerosis increased annually. In patients who had atherosclerosis with diabetes, measured levels of TNF-alpha and IL-6 were significantly higher than those in patients with atherosclerosis without diabetes (P < 0.05). The levels of TNF-alpha and IL-6 in T2DMC and ND group with atherosclerosis was significantly higher than that in two groups without atherosclerosis (P < 0.05). Patients with T2DM were divided into four groups according to their HbA1C level. There was a strong positive correlation between the levels of TNF-alpha and IL-6 and HbA1C (P > 0.05). The TNF-alpha and IL-6 levels can be used as predictors for atherosclerosis development. Compared with non-diabetic atherosclerosis, TNF-alpha and IL-6 have stronger predictive value in diabetic atherosclerosis development. One reason for hyperglycemia increasing atherosclerosis is to activate inflammatory cells and relives of inflammatory factors. Hyperglycemia can trigger inflammation, which is a quality-effect relationship reaction.

38: Clinical biochemistry, 2010 May 19, 634(1-3)
TNF-alpha -308G>A and IL-6 -174 G>C polymorphisms in the Tunisian patients with coronary artery disease.

[Abstract]OBJECTIVE: Our aim was to evaluate the contribution of tumor necrosis factor (TNF)alpha -308G>A and interleukin (IL)6 -174G>C gene promoter variants to the presence of coronary artery disease (CAD) in Tunisians. DESIGN AND METHODS: Study subjects comprised 418 angiographically- proven CAD patients, and 406 age-, gender-, and ethnic origin-matched controls. Genotyping was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. RESULTS: There were no significant differences in the allelic distribution of TNF-alpha -308A (19.6% vs. 19.0%, P=0.73), and IL-6 -174C (15.6% vs. 14.3%, P=0.47) promoter polymorphisms between CAD patients and control subjects, respectively. In addition, single locus analysis revealed no differences in genotype frequencies between the two study groups, and the combined distribution of both genotypes did not differ significantly between controls and CAD patients (P>0.05). CONCLUSION: There is no allelic or genotypic association of TNFalpha -308G>A and IL6 -174G>C promoter polymorphisms with CAD in Tunisians, thereby confirming an ethnic-selective contribution of both gene variants to CAD presence.

39: Journal of leukocyte biology, 2010 May 18, 7(1)
Increased inflammation and impaired resistance to Chlamydophila pneumoniae infection in Dusp1-/- mice: critical role of IL-6.

[Abstract]The MAPK phosphatase DUSP1 is an essential negative regulator of TLR-triggered innate immune activation. Here, we have investigated the impact of DUSP1 on inflammatory and antimicrobial host responses to the intracellular pathogen Chlamydophila pneumoniae. Following nasal infection, DUSP1-deficient mice mounted an enhanced pulmonary cytokine (IL-1beta, IL-6) and chemokine response (CCL3, CCL4, CXCL1, CXCL2), leading to increased leukocyte infiltration. Of interest, the increased inflammatory response, in the absence of DUSP1, was associated with higher bacterial numbers in the lungs, although the expression of IFN-gamma and critical antichlamydial effector molecules, such as iNOS, was intact. Blockade of IL-6 trans-signaling by injection of a soluble gp130-Fc fusion protein corrected the overshooting chemokine production as well as the increased chlamydial load in Dusp1(-/-) mice. Furthermore, IL-6 enhanced the replication of C. pneumoniae in embryonic fibroblasts in vitro. These data show that DUSP1 is required to achieve a balanced response to chlamydial infection and identify IL-6 as critical for amplifying inflammation and benefiting chlamydial growth through direct effects on infected cells.

40: Journal of immunology (Baltimore, Md. : 1950), 2010 May 10, 160(2)
Differences in Wound Healing in Mice with Deficiency of IL-6 versus IL-6 Receptor.

[Abstract]IL-6 modulates immune responses and is essential for timely wound healing. As the functions mediated by IL-6 require binding to its specific receptor, IL-6Ralpha, it was expected that mice lacking IL-6Ralpha would have the same phenotype as IL-6-deficient mice. However, although IL-6Ralpha-deficient mice share many of the inflammatory deficits seen in IL-6-deficient mice, they do not display the delay in wound healing. Surprisingly, mice with a combined deficit of IL-6 and IL-6Ralpha, or IL-6-deficient mice treated with an IL-6Ralpha-blocking Ab, showed improved wound healing relative to mice with IL-6 deficiency, indicating that the absence of the receptor contributed to the restoration of timely wound healing, rather than promiscuity of IL-6 with an alternate receptor. Wounds in mice lacking IL-6 showed delays in macrophage infiltration, fibrin clearance, and wound contraction that were not seen in mice lacking IL-6Ralpha alone and were greatly reduced in mice with a combined deficit of IL-6 and IL-6Ralpha. MAPK activation-loop phosphorylation was elevated in wounds of IL-6Ralpha-deficient mice, and treatment of wounds in these mice with the MEK inhibitor U0126 resulted in a delay in wound healing suggesting that aberrant ERK activation may contribute to improved healing. These findings underscore a deeper complexity for IL-6Ralpha function in inflammation than has been recognized previously.

41: Journal of experimental & clinical cancer research : CR, 2010 May 19, 29(1)
Effects of IL-6 and AG490 on regulation of Stat3 signaling pathway and invasion of human pancreatic cancer cells in vitro.

[Abstract]ABSTRACT: BACKGROUND: Signal transducer and activator of transcription 3 (Stat3) is a member of the Janus-activated kinase(Jak)/Stat signaling pathway. Abnormal activation of Stat3 plays a critical role in metastasis and invasion in varieties of human tumors including pancreatic cancer. This study aimed to investigate the mechanisms of activation and blocking of the Stat3 signaling pathway and its effects on invasion and metastasis of human pancreatic cancer cells. METHODS: The Jak inhibitor AG490 and interleukin-6 (IL-6) were added to the culture media of human pancreatic cancer cells SW1990 and Capan-2, respectively. Cell growth was measured by MTT assays. Western blotting and immunocytochemistry were performed to detect phosphorylated Stat3 (p-Stat3) protein, while VEGF and MMP-2 mRNA and protein expression were examined with fluorescence quantitative polymerase chain reaction and Western blotting, respectively. The invasion ability of SW1990 and Capan-2 cells was determined by cell invasion assay. RESULTS: Stat3 was activated by IL-6 in Capan-2 cells; protein expression of p-Stat3 was increased significantly in Capan-2 cells. IL-6 remarkably promoted the growth of Capan-2 cells (P < 0.05), and VEGF and MMP-2 mRNA and protein expression were increased significantly. Also, IL-6 increased the invasion ability of Capan-2 cells. AG490 inhibited Stat3 activation in SW1990 cells. Western blotting and immunocytochemistry analysis showed that p-Stat3 protein expression was decreased significantly with AG490 treatment in SW1990 cells. AG490 remarkably inhibited the growth of Capan-2 cells (P < 0.05), and VEGF and MMP-2 mRNA and protein expression was decreased significantly. And AG490 decreased the invasion ability of SW1990 cells. CONCLUSIONS: Abnormal activation of Stat3 plays an important role in the invasion and metastasis of pancreatic cancer. Activation and blocking of the Stat3 signaling pathway can affect invasion ability and expression of the VEGF and MMP-2 genes in pancreatic cancer cells. The Stat3 signaling pathway may provide a novel therapeutic target for treatment of pancreatic cancer.

42: Experimental neurology, 2010 May 14, 160(2)
Anti-IL-6-receptor antibody promotes repair of spinal cord injury by inducing microglia-dominant inflammation.

[Abstract]We previously reported the beneficial effect of administering an anti-mouse IL-6 receptor antibody (MR16-1) immediately after spinal cord injury (SCI). The purpose of our present study was to clarify the mechanism underlying how MR16-1 improves motor function after SCI. Quantitative analyses of inflammatory cells using flow cytometry, and immunohistochemistry with bone marrow-chimeric mice generated by transplanting genetically marked purified hematopoietic stem cells, revealed that MR16-1 dramatically switched the central player in the post-traumatic inflammation, from hematogenous macrophages to resident microglia. This change was accompanied by alterations in the expression of relevant cytokines within the injured spinal cord; the expression of recruiting chemokines including CCL2, CCL5, and CXCL10 was decreased, while that of Granulocyte/Macrophage-Colony Stimulating Factor (GM-CSF), a known mitogen for microglia, was increased. We also showed that the resident microglia expressed higher levels of phagocytic markers than the hematogenous macrophages. Consistent with these findings, we observed significantly decreased tissue damage and reduced levels of myelin debris and Nogo-A, the axonal growth inhibitor, by MR16-1 treatment. Moreover, we observed increased axonal regeneration and/or sprouting in the MR16-1-treated mice. Our findings indicate that the functional improvement elicited by MR16-1 involves microglial functions, and provide new insights into the role of IL-6 signaling in the pathology of SCI.

43: Rheumatology international, 2010 May 15, 160(2)
Induction of high-dose tolerance to the rat anti-mouse IL-6 receptor antibody in NZB/NZW F1 mice.

[Abstract]MR16-1 is a monoclonal antibody to mouse IL-6 receptor (IL-6R) and a good tool to investigate the involvement of IL-6 in mouse disease models. However, long-term administration of MR16-1 induced anti-MR16-1 antibody that inhibited IL-6 blocking activity of MR16-1. In this study, we treated NZB/NZW F1 (BWF1) mice with MR16-1 (0.5 mg, weekly) and tested for proteinuria (an indicator of autoimmune disease) after inducing tolerance by intraperitoneal injection of anti-CD4 mAb, or in an exploratory experiment, by prior intravenous injection of 2 mg MR16-1. Anti-CD4 mAb treatment inhibited anti-MR16-1 antibody production. And the appearance of proteinuria was significantly delayed. However, anti-CD4 mAb injection alone also significantly delayed the onset of nephritis compared with saline treatment. Intravenous MR16-1 (2 mg) followed by weekly MR16-1 injections inhibited the production of anti-MR16-1 antibody and consequently decreased the prevalence of proteinuria and the level of anti-DNA antibodies. These results established the viability of intravenous MR16-1 injection as a means of inducing tolerance. It is superior to the anti-CD4 mAb method because it enabled the effects of MR16-1 monotherapy to be evaluated without the confounding effects of anti-CD4 mAb.

44: The Journal of biological chemistry, 2010 May 11, 160(2)
Loss of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) function enhances p38 and ERK MAPKs activation increasing IL-6 synthesis in airway epithelial cells exposed to Pseudomonas aeruginosa.

[Abstract]In Cystic Fibrosis (CF), the absence of functional Cystic Fibrosis Transmembrane conductance Regulator (CFTR) translates into chronic bacterial infection, excessive inflammation, tissue damage, impaired lung function and eventual death. Understanding the mechanisms underlying this vicious circle of inflammation is important to design better therapies for CF. We found in CF lung biopsies increased immuno-reactivity for p38 MAPK activity markers. Moreover, when compared to their non-CF counterpart, airway epithelial cells expressing the most common mutation in CF (CFTRF508) were more potent at inducing neutrophil chemotaxis through increased IL-6 synthesis when challenged with Pseudomonas aeruginosa (PA) diffusible material. We then discovered that in CFTRF508 cells, the p38 and ERK MAPKs are hyper-activated in response to PA diffusible material, leading to increased IL-6 mRNA expression and stability. Moreover, although TLR5 contributes to p38 MAPK activation upon PA challenge, it only played a weak role in IL-6 synthesis. Instead, we found that the production of reactive-oxygen species (ROS) is essential for IL-6 synthesis in response to PA diffusible material. Finally, we uncovered that in CFTRF508 cells, the extracellular glutathione levels are decreased, leading to a greater sensitivity to ROS, providing an explanation for the hyper-activation of the p38 and ERK MAPKs and increased IL-6 synthesis. Taken together, our study has characterized a mechanism whereby the CFTRF508 mutation in airway epithelial cells contributes to increase inflammation of the airways.

45: Laboratory investigation; a journal of technical methods and pathology, 2010 May 10, 160(2)
Cellular and molecular mechanisms regulating the hepatic erythropoietin expression during acute-phase response: a role for IL-6.

[Abstract]The source of circulating erythropoietin (EPO), the mediators and the mechanisms involved in the upregulation of EPO gene expression during acute-phase reaction are still poorly understood. Acute-phase reaction was induced by either intramuscular turpentine oil (TO) or intraperitoneal lipopolysaccharide (LPS) administration into wild-type and interleukin (IL)-6 knockout (KO) mice. Animals were killed at different time points and blood, liver and muscle tissue were collected. Serum levels of EPO were measured by enzyme-linked immunoadsorbent assay; liver and injured muscle samples were processed for RNA isolation and for protein analysis. EPO, hypoxia-inducible factors 1alpha and 2alpha (HIF-1alpha and HIF-2alpha) mRNA were analyzed by RT-PCR and the protein levels were analyzed by western blot and electrophoretic mobility shift assay. HIF-1alpha and HIF-2alpha localization was performed through immunofluorescence staining. EPO, HIF-1 and HIF-2 gene and protein expression levels were also analyzed in isolated mouse hepatocytes after stimulation with IL-6. In the wild-type animals, EPO serum levels increased dramatically at 12 h after the insults together with the hepatic gene expression. In TO-treated animals, the EPO gene expression reached an 8.2-fold increase at 12 h, and in LPS-treated mice a similar induction was recorded at 6 h (about 4.5-fold increase). In the IL-6KO strain, the upregulation after the inflammatory stimuli was much lower (only 2.0-fold increase). A progressive upregulation of HIF-1alpha and HIF-2alpha was detectable until 6 h after the insults, but only HIF-1alpha upregulation was reduced in IL-6KO mice. In isolated hepatocytes, stimulation with a single dose of IL-6 induced a nuclear accumulation of HIF-1alpha, in parallel with an increase of EPO mRNA. No effect on HIF-2alpha expression was found. IL-6 appears to be the main regulator of EPO gene expression and a major contributor for HIF-1alpha induction in hepatocytes and Kupffer cells during acute-phase response. The increase of HIF-2alpha, predominantly expressed in endothelial cells and fibroblast-like cells, seems not to be affected by the lack of IL-6.Laboratory Investigation advance online publication, 10 May 2010; doi:10.1038/labinvest.2010.85.

46: Aging clinical and experimental research, 2010 May 6, 160(2)
Serum Il-6 and IGF-1 improve the clinical prediction of functional decline after hospitalization in older patients.

[Abstract]Background and aims. Although inflammatory and hormonal makers have been associated with further functional adverse outcomes in community-dwelling seniors, these markers have not been studied in acutely ill older patients in that perspective. This prospective study was designed to determine if biological markers might improve the predictive value of a clinical screening tool assessing the risk of functional decline in hospitalized older patients. Methods. Patients aged 75 years and over admitted for hip fracture, acute heart failure or infection (N=118) were recruited. The clinical screening tool SHERPA was filled on admission, with concomitant measurement of interleukin-6 (IL-6), insulin-like growth factor 1 (IGF-1), C-reactive protein (CRP), white blood cells, urea, albumin, prealbumin and total cholesterol. Functional decline was defined as decrease of one point in activities of daily living scale between preadmission and 3-months post-discharge status. We compared the discrimination calibration of SHERPA versus SHERPA +, a logistic regression model including SHERPA and selected biomarkers. Results. Three months after discharge, functional decline occurred in 46 patients. Interleukin-6 (IL-6) and insulin-like growth factor 1 (IGF-1) were selected since their levels were significantly different between decliners and non decliners, and were included in the new logistic regression model SHERPA+. Areas under the ROC curve [95%CI] for functional decline prediction were 0.73 [0.63-0.81] for SHERPA versus 0.79 [0.69-0.86] for SHERPA+ (p=0.14). SHERPA+ however was better calibrated, as the average predicted risk of functional decline within subgroups matched well the proportion that actually experienced functional decline (Brier score=0.185). Since functional decline was higher in patients with hip fracture, the SHERPA+ model was challenged by including the diagnosis. Only SHERPA, IGF-1 and diagnosis were significantly associated with functional decline. Conclusions. Selected biological markers may improve marginally the clinical prediction of post-discharge functional decline in hospitalized patients. The predictive value of these biomarkers is not fully independent of disease status. Further studies are needed to confirm these results in a cohort representative of older patients admitted through the emergency department.

47: Scandinavian journal of clinical and laboratory investigation, 2010 May 7, 160(2)
Anti-inflammatory effect of biological treatment in patients with inflammatory bowel diseases: Calprotectin and IL-6 changes do not correspond to sRAGE changes.

[Abstract]Abstract Aim. The main objective was to examine the relationship between the soluble receptor for advanced glycation end products (sRAGE) and calprotectin concentrations in faeces and serum of patients with inflammatory bowel diseases (IBD) during biological treatment with infliximab. Materials and methods. A total of 29 IBD patients treated with infliximab were evaluated. Calprotectin and sRAGE in serum and faeces and serum IL-6 and CRP were measured during the induction regimen of infliximab treatment at weeks (W) 0, 2 and 10. Results. At W0, a significant increase in faecal calprotectin was found in IBD compared to healthy persons (690 +/- 696 mug/g and 23 +/- 7 mug/g, respectively, p < 0.001). No clear difference was found in serum sRAGE levels in IBD cohort compared to healthy controls (772 +/- 274 pg/mL and 720 +/- 107 pg/mL, respectively, p = 0.159); however, a significant negative correlation was found between faecal calprotectin levels and serum concentrations of sRAGE in the active IBD cohort (r = -0.518, p = 0.004). In the stool eluates, sRAGE levels were non-measurable. In the group of responders-to-treatment, the initial surge in both faecal and serum calprotectin levels as well as CRP and IL-6 was followed by a significant decrease on W10. Surprisingly, no significant changeovers were seen in serum sRAGE concentrations in responders neither in W2 nor in W10. Conclusions. Unlike other examined local and systemic inflammatory markers, serum sRAGE did not change during the infliximab treatment, despite the initial correlation with the degree of mucosal inflammation.

48: Journal of agricultural and food chemistry, 2010 May 5, 160(2)
Chrysin Suppresses IL-6-Induced Angiogenesis via Down-regulation of JAK1/STAT3 and VEGF: An in Vitro and in Ovo Approach.

[Abstract]Chrysin, 5,7-dihydroxyflavone, possesses many biologic properties. This study aimed to investigate the effects and molecular mechanisms of chrysin on IL-6-induced angiogenesis in vitro and in ovo. Chicken chorioallantoic membrane assay, an in ovo angiogenesis assay, showed chrysin significantly suppressed IL-6-induced neovascularization. Furthermore, chrysin significantly suppressed human umbilical vein endothelial cell (HUVECs) migration and tube formation. The signaling pathway involved in chrysin-related antiangiogenesis was also investigated. The data indicated that chrysin is able to down-regulate the expression of glycoprotein 130 (gp130), soluble IL-6 receptor (IL-6R), phosphorylated JAK1 and STAT3, and VEGF in HUVECs. The IL-6-induced binding of STAT3 was significantly suppressed by chrysin. Moreover, chrysin did not further suppress VEGF expression with STAT3 knocked down. Taken together, the results show that chrysin suppresses IL-6-induced angiogenesis through modulation of the sIL-6R/gp130/JAK1/STAT3/VEGF signaling pathway. Chrysin may provide new therapeutic potential for IL-6-induced pathological angiogenesis.

49: Biochimica et biophysica acta, 2010 May 6, 160(2)
Inactivation of IL-6 and soluble IL-6 receptor by neutrophil derived serine proteases in cystic fibrosis.

[Abstract]The ability of IL-6 to signal via both membrane bound and soluble receptors is thought to explain the capacity of this cytokine to act in both the initiation and resolution of acute inflammatory responses. In cystic fibrosis (CF), poorly resolved neutrophillic inflammation of the lungs is a primary cause of morbidity and mortality. Expression of IL-6 has been reported to be low in CF lung secretions, despite ongoing inflammation, but the status of soluble IL-6 receptor (sIL-6R) in these patients is unknown. We hypothesised that sIL-6R may be an important potentiator of IL-6 activity in CF associated lung disease. IL-6, sIL-6R and sgp130 (a natural antagonist of responses mediated by the sIL-6R) were analysed by ELISA and Western blot in bronchoalveolar lavage fluid (BALF) from 28 paediatric CF patients and nine non-CF controls. Total cell counts in CF were four fold higher compared to controls (median: 1.4x10(6) cells/ml v. 0.35x10(6) cells/ml in controls) (p<0.001) and the infiltrate was dominated by neutrophils which were elevated by 89 fold (0.62x10(6) cells/ml v. 0.007x10(6) cells/ml in controls) (p<0.001). Other markers of inflammation such as IL-8 and MCP-1 were elevated 17.5 and 3.8 fold respectively (IL-8; median: 1122pg/ml v. 64pg/ml in controls, p<0.01 and MCP-1; median: 692pg/ml v. 182pg/ml in controls, p<0.05). IL-6, although present in 23/32 CF BALF specimens compared to 1/9 controls (p<0.01), was weakly expressed (median: 50pg/ml). Expression of sIL-6R and sgp130 in CF was no different to control patients. We tested whether weak expression of all three molecules was due to degradation by CF BALF. Degradative activity was observed in association with BALF elastase activity and could be specifically blocked by serine protease inhibitors. Degradation of sIL-6R by purified serine proteases (elastase, cathepsin G and proteinase 3) was also observed leading to a loss of trans-signalling activity. Interestingly, sIL-6R was protected from proteolysis by interaction with IL-6. Our data identify and define a novel protease mediated deficiency of IL-6 signalling in the CF lung.

50: Spine, 2010 Aug 15, 35(18)
Lack of Association Between the Promoter Polymorphisms of MMP-3 and IL-6 Genes and Adolescent Idiopathic Scoliosis: A Case-Control Study in a Chinese Han Population.

[Abstract]STUDY DESIGN.: Case-control study. OBJECTIVE.: This study is to replicate the association between the promoter polymorphisms of matrix metalloproteinase (MMP)-3 (-1171 5A/6A rs3025058) and interleukin (IL)-6 genes (-174G/C rs1800795) and adolescent idiopathic scoliosis (AIS) in a Chinese Han population. SUMMARY OF BACKGROUND DATA.: Recently, promoter polymorphisms in MMP-3 and IL-6 have been reported to be associated with AIS. Such genetic association, if confirmed by replication in other samples, would point to a primary degenerative defect in the disc or nucleus pulposus and inflammation as the key pathogenic mechanisms of AIS. METHODS.: A total of 487 Chinese girls with AIS and 494 healthy age-matched adolescent girls were recruited consecutively during a 3-year period. The same genotyping technique as the original report was used to detect promoter polymorphisms of the MMP-3 and IL-6 genes. Statistical analysis of genotype frequencies between AIS patients and normal controls were performed by chi test. RESULTS.: In this association study of the MMP-3 polymorphism and the risk of scoliosis, no significant difference was found between cases and controls, both in term of allelic association (6A: 81.2% in cases vs. 81.8% in controls, 5A: 18.8% in cases vs. 18.2% in controls, P = 0.745) or genotype association (6A/6A: 65.9% in cases vs. 66.2% in controls, 5A/6A: 30.6% in cases vs. 31.2% in controls, and 5A/5A: 3.5% in cases vs. 2.6% in controls; P = 0.733). Among AIS patients, the maximal Cobb angles were also not different among MMP-3 genotypes (6A/6A: 31.1 degrees +/- 9.7 degrees , 5A/6A: 29.1 degrees +/- 10.5 degrees , and 5A/5A: 29.4 degrees +/- 11.2 degrees ; P = 0.392). As for IL-6 polymorphism, -174G/C polymorphism was not found in the Chinese AIS patients, and all 100 AIS patients and 100 normal controls were found to carry the G/G wild type. CONCLUSION.: This study did not find any significant association of promoter polymorphisms of the MMP-3 (-1171 5A/6A rs3025058) and IL-6 gene (-174G/C rs1800795) with AIS. The results indicate that the MMP-3 promoter polymorphism is not associated with AIS in the Chinese population. Further studies, however, are needed to rule out the potential association with other promoter polymorphisms in IL-6.

51: Rheumatology (Oxford, England), 2010 Aug, 49(8)
Vitamin D3 down-regulates intracellular Toll-like receptor 9 expression and Toll-like receptor 9-induced IL-6 production in human monocytes.

[Abstract]Objective. To determine whether vitamin D(3) modulates monocytic expression of intracellular Toll-like receptors (TLRs) 3, 7 and 9. Methods. Human monocytes were isolated from peripheral blood and cultured with 100 nM vitamin D(3) for 24, 48 and 72 h. Expression of CD14 and TLR2, TLR3, TLR4, TLR7 and TLR9 were examined by flow cytometry. Monocytes exposed to vitamin D(3) for 48 h were then stimulated with a TLR9 agonist for a further 24 h. The level of IL-6 secretion was measured by ELISA. Results. CD14 was up-regulated, whereas TLR2, TLR4 and TLR9 expression was down-regulated by vitamin D(3) exposure in a time-dependent manner. TLR3 expression was unaffected by vitamin D(3) and there was no measurable expression of TLR7 on the monocytes. TLR9-induced IL-6 production was impaired in monocytes treated with vitamin D(3) compared with untreated cells. Conclusion. The intracellular TLRs are differentially regulated by vitamin D(3), with TLR9 being down-regulated by vitamin D(3) exposure whereas TLR3 was unaffected. This decreased TLR9 expression in monocytes had a downstream functional effect as these cells subsequently secreted less IL-6 in response to TLR9 challenge. This may have significant biological relevance and may be a factor in the association of vitamin D deficiency with susceptibility to autoimmune disease.

52: Archives of oral biology, 2010 Jul, 55(7)
Gingival overgrowth in cyclosporine, tacrolimus, or sirolimus-based immunosuppressive regimens and the single nucleotide IL-6 (-174 G/C) gene polymorphism.

[Abstract]OBJECTIVE: Interleukin-6 (IL-6) may be involved in drug-induced gingival overgrowth (GO). The present study was conducted to assess the association between IL-6 (-174 G/C) gene polymorphism and GO in renal transplant recipients under cyclosporine (CsA), tacrolimus (Tcr), or sirolimus (Sir)-based regimens. METHODS: Within an eligible population, 45 unrelated subjects were selected for each CsA, Tcr, and Sir group, totaling a sample of 135 subjects. GO was visually assessed and subjects were assigned as controls (non-responders) or cases (responders) in a post hoc definition. IL-6 gene polymorphism was assessed using the polymerase chain reaction amplification and digestion. The distribution of genotypes and allele frequencies in responders and non-responders were compared using the Chi-squared test. RESULTS: The number of responders was 27 (60.0%), 13 (28.9%), and 7 (15.6%) in the CsA, Tcr, and Sir groups, respectively. No differences could be observed at frequencies of -174GG, -174CG, and -174CC genotypes when comparing responders to non-responders in the CsA, Tcr, and Sir groups. Similar to genotypes, allele frequencies showed no differences between responders and non-responders in all groups. CONCLUSIONS: No association between IL-6 (-174 G/C) gene polymorphism and gingival overgrowth was observed in renal transplant recipients under CsA, Tcr, or Sir-based immunosuppressive maintenance regimens.

53: Oncology reports, 2010 Jun, 23(6)
IL-6 augments the invasiveness of U87MG human glioblastoma multiforme cells via up-regulation of MMP-2 and fascin-1.

[Abstract]Invasion into adjacent brain parenchyma is the key cause of recurrent human glioblastoma multiforme (GBM). The role of interleukin 6 (IL-6) in the malignant progression of glioma remains undefined. Here, we found that IL-6 promotes the invasion of U87 MG human glioma cells but not in U343 cells. An advanced level of STAT3 activity, and increased expression and secretion of MMP-2, induced by IL-6 in U87 MG cells were observed. Blocking the STAT3 pathway with specific inhibitors of STAT3, JSI-124 or small interfering RNA (siRNA), inhibited the invasion of U87MG promoted by IL-6 with concomitant down-regulation of MMP-2. Furthermore, rapid up-regulation of fascin-1 (a cell motility-related protein) induced by IL-6 was apparent in U87MG cells. However, this up-regulation of fascin-1 was not inhibited by JSI-124 or siRNA. These results suggest that the STAT3 pathway and fascin-1 may play crucial roles in the invasiveness of U87MG cells promoted by IL-6.

54: American journal of physiology. Regulatory, integrative and comparative physiology, 2010 Jul, 299(1)
Stress activation of IL-6 neurons in the hypothalamus.

[Abstract]An emerging literature attests to the ability of psychological stress to alter the inflammatory cytokine environment of the body. While the ability of stress to cause cytokine release is well established, the neural pathways involved in this control have yet to be identified. This study tests the hypothesis that IL-6 neurons of the hypothalamo-neurohypophyseal system (HNS), a neural pathway proposed to secrete IL-6 into the circulation, are activated in response to psychological stress. Colocalization studies confirm robust expression of IL-6 in cell bodies and fibers of vasopressin (but not oxytocin) neurons of the paraventricular (PVN) and supraoptic nucleus (SON) of the rat hypothalamus. In response to restraint, there was a greater increase in c-Fos expression in SON IL-6-positive (IL-6+) neurons. In addition, both psychogenic (restraint) or systemic stress (hypoxia) lead to phosphorylated ERK induction only in IL-6+ magnocellular neurons, indicating selective activation of the MAPK signaling pathway in the IL-6 subset of magnocellular neurons. Finally, restraint upregulated IL-6 mRNA expression in both the PVN and SON, which was accompanied by a four-fold increase in circulating IL-6. The data indicate that noninflammatory stressors selectively activate IL-6 magnocellular neurons, upregulate IL-6 gene expression in the PVN and SON, and increase plasma IL-6. In summary, results show that IL-6 neurons of the HNS are a recruited component of the response to psychological stress.

55: Current pharmaceutical biotechnology, 2010 Apr 26, 33(5)
Myocardial Expression of TNF-alpha, IL-1beta, IL-6, IL-8, IL-10 and MCP-1 After a Single MDMA Dose Administered in a Rat Model.

[Abstract]Indirect effects of 3,4-Methylenedioxy-N-methylamphetamine (MDMA) and metabolites on the cardiac cells are well-known, the mechanism(s) underlying direct MDMA-induced cardiotoxicity remaining to be clarified. To better understand the immuno-inflammatory phenomena accompanying the cardiac alterations during MDMA administration, we conducted a study in an in vivo animal model to evaluate the cellular morphological alterations related to the biological response between MDMA administration and inflammatory cytokines (tumor necrosis factor-alpha, IL-1beta, IL-6, 8, 10, and monocyte chemotactic protein-1). A total of 25 male rats were used. The effects were evaluated at 6, 16 and 24hours after a single dose MDMA administered (20 mg/kg i.p.). We found high levels of the cardioinhibitory cytokines in rat heart after 3 and 6hs from MDMA administration. Strongest reaction was observed at 24hs for TNF-alpha, IL-1beta, IL-6, 8, 10 and for MCP-1. Furthermore, we still determined the presence of MDMA and MDA in the plasma of rats treated with MDMA intra-peritoneal single injection; it was present as early at 6hs and still present 24hs after treatment. Western blot analysis in cardiac samples demonstrated the IL-1beta and IL-6 reactions in rats died spontaneously at fourth hour. The rise of the selective cardioinhibitory cytokines may be interpreted as the adaptive response of jeopardized myocardium to the cardiac dysfunction resulting from MDMA injection.

56: Diabetologia, 2010 Apr 22, 33(5)
IL-6 deficiency in mice neither impairs induction of metabolic genes in the liver nor affects blood glucose levels during fasting and moderately intense exercise.

[Abstract]AIMS/HYPOTHESIS: Fasting and exercise are strong physiological stimuli for hepatic glucose production. IL-6 has been implicated in the regulation of gluconeogenic genes, but the results are contradictory and the relevance of IL-6 for fasting- and exercise-induced hepatic glucose production is not clear. METHODS: Investigations were performed in rat hepatoma cells, and on C57Bl6 and Il6 ( -/- ) mice under the following conditions: IL-6 stimulation/injection, non-exhaustive exercise (60 min run on a treadmill) and fasting for 16 h. Metabolite analysis, quantitative real-time PCR and immunoblotting were performed. RESULTS: IL-6 stimulation of rat hepatoma cells led to higher glucose production. Injection of IL-6 in mice slightly increased hepatic Pepck (also known as Pck1) expression. Fasting of Il6 ( -/- ) mice for 16 h did not alter glucose production compared with wild-type mice, since plasma glucose concentrations were similar and upregulation of phosphoenolpyruvate carboxykinase (PEPCK) and Pgc-1alpha (also known as Ppargc1a) expression was comparable. In the non-fasting state, Il6 ( -/- ) mice showed a mild metabolic alteration including higher plasma glucose and insulin levels, lower NEFA concentrations and slightly increased hepatic PEPCK content. Moderately intense exercise resulted in elevated IL-6 plasma levels in wild-type mice. Despite that, plasma glucose, insulin, NEFA levels and hepatic glycogen content were not different in Il6 ( -/- ) mice immediately after running, while expression of hepatic G6pc, Pgc-1alpha, Irs2 and Igfbp1 mRNA was similarly increased. CONCLUSIONS/INTERPRETATION: These data suggest that in mice IL-6 is not essential for physiologically increased glucose production during fasting or non-exhaustive exercise.

57: The Journal of biological chemistry, 2010 Apr 20, 33(5)
Apobec-1 complementation factor (ACF) modulates liver regeneration by post-transcriptional regulation of IL-6 mRNA stability.

[Abstract]Apobec-1 complementation factor (ACF) is the RNA binding subunit of a core complex that mediates C-to-U RNA editing of apolipoprotein B (apoB) mRNA. Targeted deletion of the murine Acf gene is early embryonic lethal and Acf null (ko) blastocysts fail to implant and proliferate, suggesting that ACF plays a key role in cell growth and differentiation. Here we demonstrate that heterozygous Acf ko mice exhibit decreased proliferation and impaired liver mass restitution following partial hepatectomy (PH). In order to pursue the mechanism of impaired liver regeneration we examined activation of interleukin 6 (IL-6) a key cytokine required for induction of hepatocyte proliferation following PH. Peak induction of hepatic IL-6 mRNA abundance post PH was attenuated more than 80% in heterozygous Acf ko mice, along with decreased serum IL-6 levels. IL-6 secretion from isolated Kupffer cells (KC) was two-fold greater in wild-type compared to heterozygous Acf ko mice. Recombinant ACF bound an AU-rich region in IL-6 3 prime UTR with high affinity and IL-6 mRNA half-life was significantly shorter in KC isolated from heterozygous Acf ko mice compared to wild type controls. These findings suggest that ACF regulates liver regeneration following PH at least in part by controlling the stability of IL-6 mRNA. The results further suggest a new RNA target and an unanticipated physiological function for ACF beyond apoB RNA editing.

58: Cytokine, 2010 Aug, 51(2)
IL-6 and IL-1 synergistically enhanced the production of MMPs from synovial cells by up-regulating IL-6 production and IL-1 receptor I expression.

[Abstract]In the present study, we investigated potential synergism between IL-6 and IL-1 for the production of matrix metalloproteinases (MMPs) by the synovial cell line SW982. Cells were cultured with different combinations of IL-6, soluble IL-6 receptor (sIL-6R) and IL-1beta for 24h and production of MMPs was then measured. IL-6+sIL-6R, but not IL-6 alone, induced MMP-13 and MMP-3 production. IL-1beta also induced production of MMPs. Of interest, addition of IL-6+sIL-6R together with IL-1beta synergistically increased MMP production. Next, we analyzed the mechanism responsible for the synergistic effects of IL-6+sIL-6R and IL-1beta in combination. IL-1beta-induced MMP production was significantly augmented in the presence of sIL-6R. IL-1beta as well as IL-6+sIL-6R induced IL-6 production. Moreover, IL-6+sIL-6R significantly augmented expression of IL-1RI, but not IL-1RII, in SW982 cells. Responsiveness to IL-1beta was much higher in IL-6+sIL-6R-pretreated cells than non-treated cells in terms of MMP production. Finally, IL-6+sIL-6R-induced IL-1RI expression was inhibited by a STAT pathway inhibitor, but not a MAPK pathway inhibitor. These results suggest that increased expression of IL-1RI stimulated by IL-6+sIL-6R and the increased production of IL-6 on exposure to IL-1beta and IL-6+sIL-6R are involved in the observed synergistic effect on the production of MMPs by SW982 cells.

59: Cell research, 2010 Apr 13, 221(1-2)
Fra-1 protooncogene regulates IL-6 expression in macrophages and promotes the generation of M2d macrophages.

[Abstract]The tumor microenvironment (TME) plays a prominent role in the growth of tumor cells. As the major inflammatory component of the TME, M2d macrophages are educated by the TME such that they adopt an immunosuppressive role that promotes tumor metastasis and progression. Fra-1 forms activator protein-1 heterodimers with Jun partners and drives gene transcription. Fra-1 is thought to drastically induce tumorigenesis and progression. However, the functional role of Fra-1 in the generation of M2d macrophages is poorly understood to date. Here, we demonstrate that 4T1 mammary carcinoma cells, when co-cultured with RAW264.7 macrophage cells, skew the RAW264.7 macrophage cell differentiation into M2d macrophages. The 4T1 cells stimulate de novo overexpression of Fra-1 in RAW264.7 cells, and then Fra-1 binds to the interleukin 6 (IL-6) promoter to increase the production of the cytokine IL-6 in RAW264.7 cells. IL-6 acts in an autocrine fashion to skew RAW264.7 macrophage cell differentiation into M2d macrophages. These findings open new insights into how to reverse M2d macrophage-induced immune tolerance to improve the efficacy of immunotherapeutic approaches.Cell Research advance online publication 13 April 2010; doi: 10.1038/cr.2010.52.

60: Planta medica, 2010 Apr 8, 221(1-2)
Kansuinine A and Kansuinine B from Euphorbia kansui L. Inhibit IL-6-induced Stat3 Activation.

[Abstract]The current study was performed to examine the mechanisms underlying the potential effects of E. KANSUI on IL-6-induced cellular signaling in human hepatoma cells. We found that two diterpenoids, kansuinine A and B, from E. KANSUI have an inhibitory effect on IL-6-induced Stat3 activation by activating ERK1/2. Inhibition of MEK significantly blocked the effects of kansuinine A and B on IL-6-induced Stat3 activation and tyrosine phosphorylation. These results suggest that blocking of IL-6-induced signal transduction is partially due to the sustained activation of ERK1/2 by kansuinine A and B, which in turn results in an increase of Stat3 serine phosphorylation and SOCS-3 expression. Treatment with kansuinine A and B represents a novel method to block these IL-6-induced effects.

61: American journal of respiratory cell and molecular biology, 2010 Apr 8, 221(1-2)
Particulate Matter Induces IL-6 Translocation from the Lung to the Systemic Circulation.

[Abstract]The biological mechanisms responsible for an association between elevated ambient particulate matter (PM) levels and increased cardiovascular morbidity and mortality are still unclear. Our laboratory has shown that PM exposure induces systemic inflammation that contributes to vascular dysfunction. This study was designed to determine whether the lung is a major source of systemic inflammatory mediators using interleukin-6 (IL-6) as a surrogate marker and the impact on vascular dysfunction following PM less than 10 microm in diameter (PM10) exposure. C57BL/6 mice were exposed to single instillation of PM10 (10 or 200 microg) or saline intratracheally. Following 4 or 24 hours after exposure, venous and arterial blood samples were collected from the right atrium and descending aorta simultaneously. IL-6 levels were measured in bronchoalveolar lavage fluid (BALF) and serum samples. Vascular functional responses to acetylcholine (ACh) and phenylephrine were measured using the abdominal aorta. IL-6 levels in BALF samples were increased at 4 and 24 hours after PM10 exposure. At the baseline, IL-6 levels in venous blood were higher than those in arterial blood. PM10 exposure reversed this arteriovenous gradient 4 hours after exposure. The relaxation responses of the abdominal aorta to ACh decreased 4 hours after 200 microg PM10 exposure. In IL-6 knockout mice, instillation of recombinant IL-6 increased IL-6 levels in the blood and PM10 exposure did not cause vascular dysfunction. These results support our hypothesis that PM10 exposure increases pulmonary inflammatory mediators which translocate to the circulation contributing to the systemic inflammation with downstream effects such as vascular dysfunction.

62: European journal of immunology, 2010 Apr 6, 223(2)
Epidermal growth factor receptor activation during allergic sensitization affects IL-6-induced T cell influx to airways in a rat model of asthma.

[Abstract]EGFR is involved in cell differentiation and proliferation in airways and may trigger cytokine production by T cells. We hypothesized that EGFR inhibition at the time of allergic sensitization may affect subsequent immune reactions. Brown Norway rats were sensitized with OVA, received the EGFR tyrosine kinase inhibitor, AG1478 from days 0 to 7 and OVA challenge on day 14. OVA-specific IgE in serum and cytokines and chemokines in BAL were measured 24 h after challenge. To evaluate effects on airway hyperresponsiveness, rats were sensitized, treated with AG1478, intranasally challenged, and then AHR was assessed. Furthermore chemotactic activity of BALF for CD4+T cells was examined. The eosinophils, neutrophils and lymphocytes in BAL were increased by OVA and only the lymphocytes were reduced by AG1478. OVA significantly enhanced IL-6 level in BAL, which was inhibited by AG1478. However AHR, OVA-specific IgE and IL-4 mRNA expression in CD4+T cells were not affected by AG1478. BALF from OVA-sensitized/challenged rats induced CD4+T cell migration, which was inhibited by both AG1478 treatment in vivo and neutralization of IL-6 in vitro. EGFR activation during sensitization may affect the subsequent influx of CD4+T cells to airways, mainly mediated through IL-6.

63: Journal of neuro-oncology, 2010 Apr 2, 223(2)
IL-6 promotion of glioblastoma cell invasion and angiogenesis in U251 and T98G cell lines.

[Abstract]Interleukin-6 (IL-6) is a growth and survival factor in human glioblastoma cells and plays an important role in malignant progression. However, its role in glioblastoma invasion is still unknown. This study shows how IL-6 promotes cell invasion and migration in U251 and T98G glioblastoma cell lines. The underlying mechanism includes both protease-dependent and -independent manners. Stimulation with IL-6 increased MMP9 expression in the two cell lines but had no influence on MMP2 expression. Fascin-1 is a cell skeleton binding protein and plays a key role in cell migration and invasion. Its binding style directly influences cell morphology and tendency to become deformed. After IL-6 exposure, fascin-1 expression increased in an IL-6 dose-dependent manner. Immunofluorescence also revealed that the binding style of fascin-1 had changed after IL-6 exposure, resulting in a more invasive phenotype of the cells. Three most commonly emphasized invasion-associated signaling pathways, including JAK-STAT3, p42/44 MAPK, and PI3K/AKT, were verified to further illustrate its underlying mechanism. Only phosphorylation of STAT3 at ser 727 site paralleled the IL-6 stimulation, and JSI-124, a specific JAK-STAT3 pathway blocker, deterred the invasion and migration promotive effect of IL-6, indicating that the JAK/STAT3 pathway mediates signal transduction. Furthermore, IL-6 also acts in a paracrine fashion to promote vascular endothelial cell migration, thus facilitating tumor angiogenesis and invasion. These results suggest that IL-6 promotes glioblastoma cell invasion and angiogenesis and may be a potential anti-invasion target.

64: Molecular nutrition & food research, 2010 Mar 29, 337(1-2)
A Mediterranean diet rich in virgin olive oil may reverse the effects of the -174G/C IL6 gene variant on 3-year body weight change.

[Abstract]Only a few studies have analyzed the effects of the potential interaction between the -174G/C polymorphism of IL6 gene and the adherence to the Mediterranean diet (MD) on adiposity indexes. Our aim was to investigate the interplay between the -174G/C polymorphism of the IL6 gene and a Mediterranean-style diet on body weight changes after 3 years of nutritional intervention in a high cardiovascular risk population. A total of 737 participants, aged 55-80 years were assigned to a low-fat diet or to a Mediterranean-style diet group with high intake of virgin olive oil (VOO) or nuts. Anthropometric measurements were taken at baseline and after 3-year follow-up. The -174G/C polymorphism of the IL6 gene was genotyped. Minor allele frequency (C) was 0.39. At baseline, the CC genotype was associated with higher measures of adiposity. After 3 years, a significant interaction (p=0.028) was found between the polymorphism (GG+GC versus CC) and the nutritional intervention: CC subjects following the MD+VOO had the lowest body weight gain. In conclusion, at baseline, CC subjects for the -174G/C polymorphism of IL6 had the highest body weight and BMI. However, after 3 years of nutritional intervention with MD+VOO, these subjects were predicted to have the greatest reduction in body weight.

65: Blood, 2010 Mar 29, 337(1-2)
IL-6 increases B cell IgG production in a feed-forward pro-inflammatory mechanism to skew hematopoiesis and elevate myeloid production.

[Abstract]SHIP(-/-) animals display an age-related increase in IL-6, a decrease in B lymphopoiesis and an elevation in myelopoiesis. We investigated the origin of the IL-6 production and show that it is largely produced by peritoneal and splenic macrophages. IL-6 production by these macrophages is not a direct result of the loss of SHIP: IL-6 production is not spontaneous, is absent from bone marrow-derived macrophages, declines with prolonged culture of macrophages, and requires a stimulus present in vivo. The IL-6-rich peritoneal cavity of SHIP(-/-) mice shows >700-fold more IgG than wild-type, ~20% of which is aggregated or in an immune complex, and contains B220+ cells that secrete IgG. The SHIP-deficient peritoneal macrophages show evidence of IgG receptor stimulation. Animals lacking both the signal transducing gamma chain of IgG receptors and SHIP or Ig and SHIP produce less IL-6. The data indicate feed-forward process in which peripheral macrophages, responding through IgG receptors to secreted IgG, produce IL-6, to support further B cell production of IgG. Because of the pro-inflammatory phenotype of SHIP(-/-) animals, these findings emphasize the importance of IL-6 neutralizing strategies in autoimmune and pro-inflammatory diseases.

66: Journal of immunology (Baltimore, Md. : 1950), 2010 Mar 29, 337(1-2)
IL-17 Enhancement of the IL-6 Signaling Cascade in Astrocytes.

[Abstract]Astrocytes have important physiological roles in CNS homeostasis and serve as a bridge between the CNS and immune system. IL-17 and IL-6 are important in many CNS disorders characterized by neuroinflammation. We examined the role of IL-17 on the IL-6 signaling cascade in primary astrocytes. IL-17 functioned in a synergistic manner with IL-6 to induce IL-6 expression in astrocytes. The synergistic effect involved numerous signaling pathways including NF-kappaB, JNK MAPK, and p38 MAPK. The NF-kappaB pathway inhibitor BAY-11, JNK inhibitor JNKi II, and p38 inhibitor SB203580 suppressed the synergistic effect of IL-6 and IL-17 on IL-6 expression. IL-17 synergized with IL-6 to enhance the recruitment of activated NF-kappaB p65, c-Fos, c-Jun, and the histone acetyltransferases CREB-binding protein and p300 to the IL-6 promoter in vivo to induce IL-6 transcription. This was accompanied by enhanced acetylation of histones H3 and H4 on the IL-6 promoter. Moreover, we elucidated an important role for suppressor of cytokine signaling (SOCS) 3 in IL-17 enhancement of IL-6 signaling in astrocytes. SOCS3 small interfering RNA knockdown and SOCS3 deletion in astrocytes augmented the synergistic effect of IL-6 and IL-17 due to an enhancement of activation of the NF-kappaB and MAPK pathways. These results indicate that astrocytes can serve as a target of Th17 cells and IL-17 in the CNS, and SOCS3 participates in IL-17 functions in the CNS as a negative feedback regulator.

67: Cytokine, 2010 Mar 27, 337(1-2)
Disaccharide derived from chondroitin sulfate A suppressed CpG-induced IL-6 secretion in macrophage-like J774.1 cells.

[Abstract]Interleukin (IL)-6 secretion from macrophage cells is known to be induced by toll-like receptor (TLR) 9 ligands, CpG (microbial DNA sequences containing unmethylated CpG dinucleotides). We have found, using macrophage-like J774.1 cells, that this induction was dramatically suppressed by a disaccharide derived from chondroitin sulfate A (Di-4S), but not by chondroitin sulfate A (CS-A) itself. The suppression of IL-6 secretion by Di-4S occurred at protein and mRNA expression levels. Di-4S inhibited the degradation of interleukin-1 receptor-associated kinase 1 (IRAK1) in the signaling pathway mediated by myeloid differentiation primary response gene (88) (MyD88) when stimulated by TLR9 activation. In addition to suppressing IRAK1 activation, interference with CpG-TLR9 interaction by Di-4S is also suggested to be one of the mechanisms. Oligosaccharides derived from chondroitin sulfates would be effective suppressing agents for the TLR9-mediated inflammation reaction.

68: Cancer causes & control : CCC, 2010 Mar 24, 12(2)
Serum CRP and IL-6, genetic variants and risk of colorectal adenoma in a multiethnic population.

[Abstract]Chronic inflammation, which is suspected to play a role in the development of colorectal cancer (CRC), has rarely been studied in colorectal adenoma. We investigated the inter-relationships of serum levels of the inflammatory proteins CRP and in IL-6, single nucleotide polymorphisms (SNPs) in the CRP (rs1205, rs1130864, rs1800947) and IL6 (rs1800795) genes, and lifestyle factors with colorectal adenoma in a sigmoidoscopy-based case-control study of 271 adenoma cases and 539 age-, sex-, and race/ethnicity-matched controls in Hawaii. We found no association of serum CRP or IL-6 levels with the risk of adenoma. A multiple regression with stepwise selection identified elevated BMI, Caucasian and Native Hawaiian versus Japanese race/ethnicity, and current smoking as being associated with significantly higher serum CRP and IL-6 levels. Female versus male gender was also associated with higher CRP levels and older age with higher IL-6 levels. The C allele of rs1205 and the A allele of rs1130864 were significantly associated with higher serum CRP levels (p (trend): 0.0002 and 0.01, respectively), as well as with a decreased adenoma risk [rs1205: OR for CT and CC vs. TT = 0.69 (95% CI: 0.48-0.98) and 0.53 (0.34-0.83), respectively, p (trend) = 0.008; rs1130864: OR for GA and AA versus GG = 0.65 (0.45-0.93) and 0.74 (0.31-1.76), respectively, p (trend) = 0.04]. The findings of lower serum CRP and IL-6 levels in Japanese (a group with a high CRC risk) and of a decreased adenoma risk observed for alleles associated with higher circulating CRP levels suggest a protective effect for CRP in early colorectal neoplasia that warrants further study.

69: Tissue antigens, 2010 Mar 22, 107(12)
Lack of association between IL-6-174G/C gene polymorphism and Chagas disease.

[Abstract]The aim of this study was to investigate the role of the IL-6-174G/C gene polymorphism in susceptibility/resistance to Trypanosoma cruzi infection in two independent cohorts from Colombia and Peru. We determined the IL-6-174G/C genotypes in a sample of 399 seronegative individuals and 317 serologically positive patients from Colombia and Peru. All individuals are from regions where T. cruzi infection is endemic. No statistically significant differences in the frequency of IL-6-174G/C gene polymorphism between chagasic patients and controls or between asymptomatic and individuals with cardiomyopathy were observed. Our results do not support an evidence for a major role contribution of this IL-6 gene polymorphism in the susceptibility to or clinical manifestations of Chagas disease in these studied cohorts.

70: Journal of neuroimmunology, 2010 Mar 2, 115(9)
TNF-alpha, IL-1beta, IL-6, and cinc-1 levels in rat brain after meningitis induced by Streptococcus pneumoniae.

[Abstract]Bacterial meningitis caused by Streptococcus pneumoniae is associated with a significant mortality rate and persisting neurologic sequelae, including sensory-motor deficits, seizures, and impairment of learning and memory. The presence of proliferating bacteria within the subarachnoid and ventricular space compartments triggers an intense inflammatory host response at killing the invading microorganism. Proinflammatory mediators released in the process, including tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6, were shown to contribute to the development of brain injury in bacterial meningitis. Thus, the aim of this study was to verify the levels of the TNF-alpha, IL-1beta, IL-6, and CINC-1 in the rat brain after pneumococcal meningitis. The animals underwent a magna cistern tap receiving either 10microL of sterile saline as a placebo or an equivalent volume of a S. pneumoniae suspension at the concentration of 5x10(9)cfu/mL. The placebo group was killed immediately after the induction and the meningitis group at 0, 6, 12, 24, 48, and 96h after induction. The brains were removed followed by the isolation of the hippocampus and prefrontal cortex for determining TNF-alpha, IL-1beta, IL-6, and CINC-1 levels. In the hippocampus we found increased levels of the TNF-alpha only at 6h (p<0.01; F=3.777); CINC-1 levels increased at 6 and 24h (p<0.001; p<0.05; F=15.05); and IL-6 and IL-1beta levels were not altered. In the prefrontal cortex, the TNF-alpha levels were found to be increased only at 6h (p<0.05; F=4.921); IL-6 (p<0.05; F=11.69) and IL-1beta (p<0.001; F=132.0) levels were found to be increased only at 24h after meningitis induction; and CINC-1 levels were found to be increased at 6, 12, and 24h (p<0.01; p<0.01; p<0.01; F=16.86) after meningitis induction. Our data suggest that cytokine/chemokine levels can be putative biomarkers of brain damage in the first hours of the pneumococcal meningitis.

71: Journal of cell science, 2010 Mar 15, 123(Pt 6)
Cross-regulation of cytokine signalling: pro-inflammatory cytokines restrict IL-6 signalling through receptor internalisation and degradation.

[Abstract]The inflammatory response involves a complex interplay of different cytokines which act in an auto- or paracrine manner to induce the so-called acute phase response. Cytokines are known to crosstalk on multiple levels, for instance by regulating the mRNA stability of targeted cytokines through activation of the p38-MAPK pathway. In our study we discovered a new mechanism that answers the long-standing question how pro-inflammatory cytokines and environmental stress restrict immediate signalling of interleukin (IL)-6-type cytokines. We show that p38, activated by IL-1beta, TNFalpha or environmental stress, impairs IL-6-induced JAK/STAT signalling through phosphorylation of the common cytokine receptor subunit gp130 and its subsequent internalisation and degradation. We identify MK2 as the kinase that phosphorylates serine 782 in the cytoplasmic part of gp130. Consequently, inhibition of p38 or MK2, deletion of MK2 or mutation of crucial amino acids within the MK2 target site or the di-leucine internalisation motif blocks receptor depletion and restores IL-6-dependent STAT activation as well as gene induction. Hence, a novel negative crosstalk mechanism for cytokine signalling is described, where cytokine receptor turnover is regulated in trans by pro-inflammatory cytokines and stress stimuli to coordinate the inflammatory response.

72: Japanese journal of clinical oncology, 2010 Mar 1, 222(3)
Analysis of the Effect of Serum Interleukin-6 (IL-6) and Soluble IL-6 Receptor Levels on Survival of Patients with Colorectal Cancer.

[Abstract]OBJECTIVE: The correlations of serum interleukin-6 and soluble interleukin-6 receptor concentrations with clinicopathological features and survival of patients with colorectal cancer were studied. METHODS: We measured the serum levels of interleukin-6 and soluble interleukin-6 receptor in 99 colorectal cancer patients at the Chang Gung Memorial Hospital, Taiwan. The interleukin-6 and soluble interleukin-6 receptor levels were tested for their association with each other, and with the clinical parameters and outcomes. RESULTS: Both interleukin-6 and soluble interleukin-6 receptor concentrations were significantly higher in colorectal cancer patients than in normal individuals. Unlike patients with serum interleukin-6 levels >10 pg/ml, who have increased carcinoembryonic antigen levels and shorter survival, serum soluble interleukin-6 receptor levels >800 pg/ml were found in patients with stages I-II and no regional lymph nodal invasion and appeared to be a positive prognostic factor for improved survival. Especially, patients with serum interleukin-6 <10 pg/ml and soluble interleukin-6 receptor >800 pg/ml lived significantly longer. Nonetheless, the multivariate analysis showed that only tumor-node metastasis stage, metastatic status and serum interleukin-6 level were independent prognostic factors, whereas the serum soluble interleukin-6 receptor level became marginally important for survival. CONCLUSIONS: We suggest the clinical relevance of interleukin-6 and soluble interleukin-6 receptor for the survival of colorectal cancer patients. From a practical point of view, detection of the serum interleukin-6 level alone, rather than combined measurement of interleukin-6 and soluble interleukin-6 receptor, may be sufficient to independently predict survival in colorectal cancer patients.

73: Cytokine, 2010 Feb 26, 17(3-4)
Induction of IL-13 production and upregulation of gene expression of protease activated receptors in P815 cells by IL-6.

[Abstract]Interleukin (IL)-6 is a multifunctional cytokine which has been showed to induce up-regulated expression of Fc epsilon RI receptor and histamine production in mast cells. However, little is known of its effects on Th2 cytokine secretion and protease activated receptor (PAR) expression in mast cells. In the present study, we examined potential influence of IL-6 on IL-13, IL-4 and IL-10 release from P815 cells and PAR expression on P815 cells by using flow cytometry analysis, quantitative real-time PCR, ELISA and cellular activation of signaling ELISA (CASE) techniques. The results showed that IL-6 induced up to 1.8-fold increase in IL-13, but not IL-4 or IL-10 release from P815 cells, and FSLLRY-NH(2) did not affect IL-6 induced IL-13 release. Tryptase elicited 2.0-fold increase in IL-13 release from P815 cells, which can be inhibited by IL-6. IL-6 elicited the up-regulated expression of PAR-1, PAR-2, PAR-3 and PAR-4 mRNAs, but had little effects on expression of PAR proteins. U0126, PD98059 and LY204002 abolished IL-6 induced IL-13 release when they were preincubated with P815 cells, indicating ERK and Akt cell signaling pathways may be involved in the event. In conclusion, IL-6 can stimulate IL-13 release from mast cells through an ERK and Akt cell signaling pathway dependent, but PAR independent mechanism.

74: The Journal of biological chemistry, 2010 Feb 25, 17(3-4)
Foxp1/2/4-NuRD interactions regulate gene expression and epithelial injury response in the lung via regulation of IL-6.

[Abstract]To determine the underlying mechanism of Foxp1/2/4 mediated transcriptional repression, a yeast two-hybrid screen was performed which identified p66beta, a transcriptional repressor and component of the NuRD chromatin remodeling complex. We show that direct interactions between Foxp1/4 and p66beta are mediated by the CR2 domain within p66beta and the zinc finger/leucine zipper repression domain found in Foxp1/2/4. These direct interactions are functionally relevant as over-expression of p66beta in combination with Foxp factors cooperatively represses Foxp target gene expression, while loss of p66 and Foxp factors results in de-repression of endogenous Foxp target genes in lung epithelial cells. Moreover, the NuRD components HDAC1/2 associate in a macromolecular complex with Foxp proteins and loss of expression or inhibition of HDAC1/2 activity leads to de-repression of Foxp target gene expression. Importantly, we show in vivo that Foxp1 and HDAC2 act cooperatively to regulate expression of the cytoprotective cytokine IL-6, which results in increased resistance to hyperoxic lung injury in Foxp1/HDAC2 compound mutant animals. These data reveal an important interaction between the Foxp transcription factors and the NuRD chromatin remodeling complex that modulates transcriptional repression critical for the lung epithelial injury response.

75: Journal of strength and conditioning research / National Strength & Conditioning Association, 2010 Feb 18, 17(3-4)
Influence of commonly employed resistance exercise protocols on circulating IL-6 and indices of insulin sensitivity.

[Abstract]Phillips, MD, Mitchell, JB, Currie-Elolf, LM, Yellott, RC, and Hubing, KA. Influence of commonly employed resistance exercise protocols on circulating IL-6 and indices of insulin sensitivity. J Strength Cond Res 24(x): 000-000, 2010-The purpose of this project was to examine the influence of resistance exercise (RE) intensities, resulting in different total volume loads on circulating interleukin-6 (IL-6), insulin and glucose response (IGR) to a carbohydrate feeding (CHO), and whether RE-induced IL-6 was associated with postexercise IGR. Fourteen men (21.7 +/- 1.7 years, 83 +/- 14.2 kg), performed 2 RE sessions (low-intensity resulting in high volume [65% 1-repetition maximum (1RM)], LO; high intensity resulting in low volume [85% 1RM], HI); and a nonexercise control trial (CON). Resistance exercise included 3 sets (LO = 12 reps, 12 reps, and failure; HI = 8 reps, 8 reps, and failure) of 8 exercises. Blood was obtained pre- (PR) and post (PO) exercise, and 6 hours postexercise (6H). Twenty-three hours after RE or CON, participants consumed 100 g dextrose (CHO) beverage. Blood was collected before (0 minutes) and 60 minutes after CHO (n = 6, phase 1) or every 30 minutes for a 2-hour oral glucose tolerance test (n = 8; phase 2). Circulating IL-6, insulin, and glucose were analyzed via enzyme-linked immunosorbent assay, radioimmunoassay, and enzymatic methods, respectively. Total volume load was higher in LO (17,729 +/- 1,466 kg) compared with HI (13,160 +/- 1,097 kg; p < 0.001). Postexercise IL-6 was elevated (p = 0.003) in LO and HI compared with CON (7.4 +/- 1.3, 5.2 +/- 0.7, and 2.5 +/- 0.7 pg.mL, respectively), with LO IL-6 greater than HI. Areas under the curve for glucose (p = 0.081; CON: 741 +/- 46, LO: 690 +/- 28, and HI: 660 +/- 21 mM.min) and insulin (p = 0.075; CON: 6,818 +/- 1,018, LO: 5,056 +/- 869, and HI: 5,405 +/- 1,076 muIU.mL) were not different among trials (n = 8). When 0- and 60-minute values were compared (n = 14), insulin was lower at 60 minutes in LO and HI compared with CON (55 + 9.1, 83 +/- 13, 105 +/- 13 muIU.mL, respectively) with LO insulin being lower than HI (p < 0.001). No relationship was observed between PO IL-6 and IGR, but PR IL-6 was negatively related to both PR (r = -0.043, p < 0.05) and 60 minutes (r = -0.59, p < 0.01) glucose (n = 14). These results indicate that TVL contributes to RE-induced IL-6 release and that TVL may be more important than RE intensity when improvements in glucose tolerance or IS are the goal.

76: Clinical cancer research : an official journal of the American Association for Cancer Research, 2010 Feb 16, 17(3-4)
ZIP4 Regulates Pancreatic Cancer Cell Growth by Activating IL-6/STAT3 Pathway through Zinc Finger Transcription Factor CREB.

[Abstract]PURPOSE: Recent studies indicate a strong correlation of zinc transporter ZIP4 and pancreatic cancer progression; however, the underlying mechanisms are unclear. We have recently found that ZIP4 is overexpressed in pancreatic cancer. In this study, we investigated the signaling pathway through which ZIP4 regulates pancreatic cancer growth. EXPERIMENTAL DESIGN: The expression of cyclin D1, interleukin 6 (IL-6), and signal transducer and activator of transcription 3 (STAT3) in pancreatic cancer xenografts and cells were examined by real-time PCR, Bio-Plex cytokine assay, and Western blot, respectively. The activity of cAMP response element-binding protein (CREB) is examined by a promoter activity assay. RESULTS: Cyclin D1 was significantly increased in the ZIP4 overexpressing MIA PaCa-2 cells (MIA-ZIP4)-injected orthotopic xenografts and was downregulated in the ZIP4-silenced ASPC-1 (ASPC-shZIP4) group. The phosphorylation of STAT3, an upstream activator of cyclin D1, was increased in MIA-ZIP4 cells and decreased in ASPC-shZIP4 cells. IL-6, a known upstream activator for STAT3, was also found to be significantly increased in the MIA-ZIP4 cells and xenografts and decreased in the ASPC-shZIP4 group. Overexpression of ZIP4 led to a 75% increase of IL-6 promoter activity and caused increased phosphorylation of CREB. CONCLUSIONS: Our study suggest that ZIP4 overexpression causes increased IL-6 transcription through CREB, which in turn activates STAT3 and leads to increased cyclin D1 expression, resulting in increased cell proliferation and tumor progression in pancreatic cancer. These results elucidated a novel pathway in ZIP4-mediated pancreatic cancer growth and suggest new therapeutic targets, including ZIP4, IL-6, and STAT3, in pancreatic cancer treatment. Clin Cancer Res; 16(5); OF1-8.

77: Clinical biochemistry, 2010 Feb 1, 184(4)
Study of TNFalpha -308 G/A and IL6 -174 G/C polymorphisms in type 2 diabetes and obesity risk in the Tunisian population.

[Abstract]OBJECTIVES: We investigated two genetic markers in pro inflammatory molecules : TNFalpha -308 G/A and IL6 -174 G/C in order to assess their effect on type 2 diabetes (T2D) and obesity in the Tunisian population. DESIGN AND METHODS: The study sample includes 228 patients with T2D and 300 healthy controls. Genotyping of IL6 -174 G/C (rs1800795) was performed using Automated Dye Terminator Sequencing and of TNFalpha -308 G/A (rs1800629) using the LightTyper technology. RESULTS: SNPs IL6 -174 G/C and TNFalpha -308 G/A are associated neither with T2D (p=0.89, p=0.34 respectively) nor with risk for overweight (p=0.86, p=0.12 respectively) in Tunisian population. Bonferroni correction showed that the founded association of IL6 -174G/C SNP with T2D susceptibility restricted to over weighted patients (p (nominal) =0.03, p (corrected) = 0;0033) is likely to be a random result. CONCLUSION: SNPs IL6 -174 G/C and TNFalpha -308 G/A are not major contributors to T2D or obesity risk in our Tunisian population.

78: American journal of reproductive immunology (New York, N.Y. : 1989), 2010 Feb 3, 184(4)
Antiphospholipid Antibodies Limit Trophoblast Migration by Reducing IL-6 Production and STAT3 Activity.

[Abstract]Citation Mulla MJ, Myrtolli K, Brosens JJ, Chamley LW, Kwak-Kim JY, Paidas MJ, Abrahams VM. Antiphospholipid antibodies limit trophoblast migration by reducing IL-6 production and STAT3 activity. Am J Reprod Immunol 2010 Problem Women with antiphospholipid antibodies (aPL) are at risk of recurrent miscarriage and pre-eclampsia. aPL target the placenta by binding to beta(2)-glycoprotein I (beta(2) GPI) expressed by the trophoblast. The objective of this study was to evaluate if and how aPL affect first trimester trophoblast migration. Method of study First trimester trophoblast cells were treated with anti-beta(2) GPI monoclonal antibodies. Migration was determined using a two-chamber assay. Interleukin (IL)-6 production was evaluated by RT-PCR and enzyme-linked immunosorbent assay, and signal transducer and activator of transcription 3 (STAT3) activation was assessed by western blot. Results Trophoblast cells constitutively secreted IL-6 in a time-dependent manner and this directly correlated with STAT3 phosphorylation. In the presence of anti-beta(2) GPI Abs, trophoblast IL-6 mRNA levels and secretion was downregulated in a Toll-like receptor 4/MyD88-independent manner and this correlated with a reduction in phosphorylated STAT3 levels. In addition, the anti-beta(2) GPI Abs reduced the migratory potential of trophoblast. Heparin was able to reverse aPL-dependent inhibition of trophoblast IL-6 secretion and migration. Conclusion This study demonstrates that aPL limit trophoblast cell migration by downregulating trophoblast IL-6 secretion and STAT3 activity. As heparin was unable to prevent these effects, our findings may explain why women with antiphospholipid syndrome, treated with heparin, remain at risk of developing obstetrical syndromes, associated with impaired deep placentation, such as pre-eclampsia.

79: DNA and cell biology, 2010 Feb 4, 184(4)
Interleukin-6-174 G/C Polymorphism is Not Associated with IL-6 Expression and Susceptibility to Sporadic Colon Cancer.

[Abstract]Interleukin-6 (IL-6) has been implicated in tumorigenesis; however, its role is still far from being clearly defined. Regulation of IL-6 expression is highly complex, and additional complexity is introduced by single-nucleotide polymorphisms in the IL-6 gene. These single-nucleotide polymorphisms might influence mRNA transcription, which might in turn result in increased susceptibility to certain tumors. The aim of this study was to analyze IL-6 mRNA and protein expressions in sporadic colon cancer. Influence of IL-6-174 G/C polymorphism on IL-6 mRNA expression and sporadic colon cancer susceptibility was evaluated as well. The frequency of IL-6-174 G/C was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. IL-6 mRNA and protein expressions were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. No statistically significant difference in IL-6 mRNA expression in tumor tissue compared with the corresponding normal tissue was observed (p = 0.116). No correlation was found between IL-6 mRNA and protein expressions and clinicopathological features of sporadic colon tumors. There was no association of IL-6-174 G/C genotypes with IL-6 mRNA expression in colon tumors and corresponding normal mucous tissue (p = 0.355; p = 0.152). Finally, there was no association of IL-6-174 G/C with susceptibility to sporadic colon cancer.

80: Biochemical pharmacology, 2010 Jan 25, 24(1)
Lipoteichoic acid enhances IL-6 production in human synovial fibroblasts via TLR2 receptor, PKCdelta and c-Src dependent pathways.

[Abstract]Patients with rheumatoid arthritis (RA) are at increased risk of developing infections and appear to be particularly susceptible to septic arthritis. Lipoteichoic acid (LTA), a cell wall component of Gram-positive bacteia is an amphiphilic, negatively charged glycolipid. However, the effects of LTA on human synovial fibroblasts are largely unknown. We investigated the signaling pathway involved in IL-6 production stimulated by LTA in rheumatoid arthritis synovial fibroblasts (RASF). LTA caused concentration- and time-dependent increases in IL-6 production. LTA-mediated IL-6 production was attenuated by Toll-like receptor 2 (TLR2) monoclonal antibody or siRNA. Pretreatment with PKCdelta inhibitor (rottlerin), c-Src inhibitor (PP2), AP-1 inhibitor (tanshinone IIA) and NF-kappaB inhibitor (PDTC and TPCK) also inhibited the potentiating action of LTA. However, focal adhesion kinase (FAK) mutant and siRNA did not affect LTA-mediated IL-6 production. Stimulation of cells with LTA increased the PKCdelta and c-Src phosphorylation and kinase activity. LTA increased the accumulation of p-c-Jun and p-p65 in the nucleus, as well as AP-1 and NF-kappaB luciferase activity. LTA-mediated increase of AP-1 and NF-kappaB luciferase activity was inhibited by rottlerin and PP2 or TLR2 and PKCdelta siRNA or c-Src mutant. Our results suggest that LTA increased IL-6 production in human synovial fibroblasts via the TLR2 receptor, PKCdelta, c-Src, AP-1 and NF-kappaB signaling pathways.

81: Cellular signalling, 2010 Jan 25, 24(1)
Cooperation of NFkappaB and CREB to induce synergistic IL-6 expression in astrocytes.

[Abstract]Astrocytes are critical players in the innate immune response of the central nervous system. Upon encountering proinflammatory stimuli, astrocytes produce a plethora of inflammatory mediators. Here, we have investigated how beta(2)-adrenergic receptor activation modulates proinflammatory gene expression in astrocytes. We have observed that treatment of human 1321N1 astrocytes with the beta-adrenergic agonist isoproterenol synergistically enhanced TNF-alpha-induced expression of the cytokine IL-6. The effect of isoproterenol was cAMP-dependent and mediated by the beta(2)-adrenergic subtype. Using pharmacological inhibitors and siRNA we showed that protein kinase A (PKA) is an indispensable mediator of the synergy. Simultaneous induction with isoproterenol and TNF-alpha was moreover associated with combined recruitment of CREB and p65 to the native IL-6 promoter. The role of CREB and NFkappaB in promoting the synergy was corroborated using IL-6 promoter point mutants, as well as via siRNA-mediated silencing of CREB and NFkappaB. Interestingly, whereas CREB and NFkappaB usually compete for the limiting cofactor CREB binding protein (CBP), we detected enhanced recruitment of CBP at the IL-6 promoter in our system. The transcriptional synergy seems to be a gene specific process, occurring at the IL-6 and COX-2 gene, but not at other typical NFkappaB-dependent genes such as IL-8, ICAM-1 or VCAM-1. As astrocytic IL-6 overexpression has been associated with neuroinflammatory and neurodegenerative processes, our findings might have important physiological consequences.

82: Phytomedicine : international journal of phytotherapy and phytopharmacology, 2010 Jan 21, 184(3)
The fixed herbal drug composition "Saikokaryukotsuboreito" prevents bone loss with an association of serum IL-6 reductions in ovariectomized mice model.

[Abstract]Purpose: Saikokaryukotsuboreito (SRB) is a traditional Japanese herbal medicine that has been used to treat hyperlipidemia. As some studies have shown that lipid-lowering drugs reduce osteoporosis, we investigated the effect of SRB on bone metabolism in the postmenopausal period using an ovariectomized (OVX) murine model. Material and Methods: Fifteen aged 9 weeks female mice were divided into three groups (n=5 each). The OVX group and SRB group underwent bilateral ovariectomy, after which the OVX group was fed a normal diet and the SRB group fed a normal diet containing 2% SRB. The sham group underwent sham surgery and was then fed a normal diet. Eight weeks after surgery, all mice were sacrificed, and bone volume, bone histomorphometric parameters, and bone-associated phenotype were compared among the groups. Results: Compared with the OVX group, the SRB group showed suppression of bone volume loss at the tibia (SRB group: 12.7+/-0.7%, OVX group: 9.8+/-0.4%; p=0.005, ANOVA) and lumbar spine (SRB group: 15.1+/-0.9%, OVX group: 11.3+/-0.1%; p=0.031, ANOVA). A significant decrease in eroded surface was also observed in SRB-treated ovariectomized mice compared with the OVX group (p=0.022, ANOVA). We also found that serum levels of interleukin (IL)-6, a primary mediator of bone resorption, in the SRB group were significantly lower than in the OVX group (SRB: 52.5+/-6.8pg/ml; OVX: 138.0+/-23.1pg/ml; p=0.011, ANOVA). However, unexpectedly, SRB did not affect estradiol and total cholesterol in ovariectomized mice. Conclusion: SRB can prevent loss of bone volume and suppress serum IL-6 levels in this postmenopausal model and is a promising candidate for treatment of postmenopausal osteoporosis.

83: Immunopharmacology and immunotoxicology, 2010 Jan 22, 184(3)
Long-term effect of high doses glucocorticosteroids on mRNA expression for IL-6 and IL-8 in relapsed multiple sclerosis patients.

[Abstract]Glucocorticosteroids (GS) are standard treatment of multiple sclerosis (MS) relapse, but no superiority of any commonly used doses is known. The aim of present study was to evaluate mRNA expression for two cytokines: IL-6 and IL-8. Ethylenediaminetetraacetic acid blood samples from 35 MS relapse patients were obtained before therapy, after 7, 14 days, and 3 months from treatment start (500 versus 1000 mg for 5 days). Significant neurological improvement measured with EDSS was independent to GS dose. Changes of mRNA cytokines expression were more evident in higher dose group but for IL-6 mainly in females.

84: Journal of immunology (Baltimore, Md. : 1950), 2010 Jan 18, 59(2)
Loss of CD4+ T Cell IL-6R Expression during Inflammation Underlines a Role for IL-6 Trans Signaling in the Local Maintenance of Th17 Cells.

[Abstract]IL-6 responses are classically orchestrated via a membrane-bound IL-6R (CD126) alpha subunit (classical IL-6R signaling) or through a soluble form of this cognate receptor (IL-6 trans signaling). Appraisal of IL-6R expression on human and mouse T cells emphasized that IL-6R expression is closely linked with that of CCR7 and CD62L. In this regard, infiltrating effector T cells from clinical and experimental peritonitis episodes lose IL-6R expression, and anti-CD3/CD28 Ab costimulation of peripheral T cells in vitro leads to a downregulation in IL-6R expression. Consequently, IL-6 signaling through membrane-bound IL-6R seems to be limited to naive or central memory T cell populations. Loss of IL-6R expression by activated T cells further suggests that these effector cells might still retain IL-6 responsiveness via IL-6 trans signaling. Using IL-6R-deficient mice and recombinant tools that modulate the capacity of IL-6 to signal via its soluble receptor, we report that local control of IL-6 trans signaling regulates the effector characteristics of the T cell infiltrate and promotes the maintenance of IL-17A-secreting CD4(+) T cells. Therefore, we concluded that classical IL-6R signaling in naive or central memory CD4(+) T cells is required to steer their effector characteristics, whereas local regulation of soluble IL-6R activity might serve to maintain the cytokine profile of the Th cell infiltrate. Therefore, the activation status of a T cell population is linked with an alteration in IL-6 responsiveness.

85: Journal of immunology (Baltimore, Md. : 1950), 2010 Jan 18, 59(2)
Mast Cells, Histamine, and IL-6 Regulate the Selective Influx of Dendritic Cell Subsets into an Inflamed Lymph Node.

[Abstract]In response to bacterial stimuli, multiple dendritic cell (DC) populations accumulate within the draining lymph node, thus enhancing opportunities for effective T cell-DC interaction. DC subpopulations, such as plasmacytoid, CD8(+), and CD11b(+) subsets, have distinct roles in determining the nature of the immune response. The mechanisms whereby individual DC subpopulations are mobilized and the extent to which these processes are linked to increases in overall lymph node cellularity have not been determined. In the current study, the mechanisms of DC subset mobilization to the draining auricular lymph node were examined after intradermal injection of Staphylococcus aureus-derived peptidoglycan. Using mast cell-deficient mice and local mast cell reconstitution, plasmacytoid and CD8(+) DC responses were shown to be mast cell dependent, whereas the CD11b(+) DC response was not. A histamine H2 receptor-dependent, CXCL9-independent pathway controlled the selective influx of both plasmacytoid and CD11b(+) DC into the lymph node, but not lymph node cellularity. In contrast, IL-6 was important for the mobilization of CD8(+) and CD11b(+) DC. TNF and IL-1 receptor were dispensable for plasmacytoid, CD11b(+), and CD8(+) DC responses. These findings provide novel opportunities for the selective mobilization of specific DC subsets to lymph nodes and demonstrate critical roles for both histamine and IL-6 in this process.

86: Cell biology international, 2010 Jan 12, 184(2)
H2S transiently blocks IL-6 expression in rheumatoid arthritic fibroblast-like synoviocytes and deactivates p44/42 mitogen-activated protein kinase.

[Abstract]Objective: H2S represents the oldest form of treatment for patients with different types of rheumatic disorders. However, scientific reports about the beneficial effects of this form of therapy are controversial, rare and of poor scientific quality. Also little is known about the role and underlying molecular mechanisms of H2S. Therefore, this topic encouraged us to investigate the influence of H2S on fibroblasts isolated from the synovial membrane of RA patients. Methods: Fibroblast-like synoviocytes (FLSs) were incubated with different concentrations of an exogenous H2S donor (NaHS). At defined time points, secretion of IL-6 was quantified by Enzyme-linked immunosorbent assay (ELISA). Activation/deactivation of mitogen-activated protein kinases (MAPKs), p38 and p44/42 MAPK (ERK1/2), were confirmed by Western blot experiments. Results: FLSs constitutively express and secrete large quantities of IL-6 and IL-8. Data provided proves that in FLSs constitutive expression of IL-6 is transiently and partially downregulated by the short treatment of cells with low concentrations of NaHS. Another key finding is that H2S deactivates p44/42 MAPK (ERK1/2). Long-term exposure of FLSs to H2S provides stimulatory effects, leading to reinforced activation of p38 MAPK and ERK1/2 accompanied by upregulation of IL-6 expression. Conclusion: Presented data seem of importance for studying (patho-) physiological functions of H2S and also for re-evaluating sulphur spa therapy as one of the oldest forms of therapy for rheumatic disorders.

87: Annals of human genetics, 2010 Jan, 74(1)
Interaction between fibrinogen and IL-6 genetic variants and associations with cardiovascular disease risk in the cardiovascular health study.

[Abstract]The inflammatory cytokine interleukin-6 (IL-6) is a main regulator of fibrinogen synthesis, though its interaction with fibrinogen genes (FGA, FGB, FGG) and subsequent impact on cardiovascular disease (CVD) risk is not well-studied. We investigated joint associations of fibrinogen and IL6 tagSNPs with fibrinogen concentrations, carotid intima-media thickness, and myocardial infarction or ischemic stroke in 3900 European-American Cardiovascular Health Study participants. To identify combinations of genetic main effects and interactions associated with outcomes, we used logic regression. We also evaluated whether the relationship between fibrinogen SNPs and fibrinogen level varied by IL-6 level using linear regression models with multiplicative interaction terms. Combinations of fibrinogen and IL6 SNPs were significantly associated with fibrinogen level (p < 0.005), but not with other outcomes. Fibrinogen levels were higher in individuals having FGB1437 (rs1800790) and lacking FGA6534 (rs6050) minor alleles; these SNPs interacted with IL6 rs1800796 to influence fibrinogen level. Marginally significant (p= 0.03) interactions between IL-6 level and FGA and FGG promoter SNPs associated with fibrinogen levels were detected. We identified potential gene-gene interactions influencing fibrinogen levels. Although IL-6 responsive binding sites are present in fibrinogen gene promoter regions, we did not find strong evidence of interaction between fibrinogen SNPs and IL6 SNPs or levels influencing CVD.

88: Psychoneuroendocrinology, 2009 Dec 29, 9(1)
Disgust affects TNF-alpha, IL-6 and noradrenalin levels in patients with obsessive-compulsive disorder.

[Abstract]Neurobiological research of obsessive-compulsive disorder (OCD) has rarely taken in account the context dependent evocation of obsessive-compulsive symptoms. To bypass this obstacle, this study investigated neurobiological parameters during a standardized disgust provocation paradigm in patients with OCD and healthy controls. Ten OCD patients and 10 healthy controls were exposed to 9 disgust related items using a standardized provocation paradigm. Catecholamines and cortisol in plasma and lipopolysaccharide (LPS) stimulated levels of TNF-alpha and IL-6 by peripheral leucocytes were assessed along with severity of obsessive-compulsive symptoms, disgust, and anxiety levels using Visual Analogue Scales prior, during and after a provocation paradigm. Noradrenalin levels increased, while LPS stimulated TNF-alpha and IL-6 by peripheral leucocytes decreased during exposure to disgust related objects in OCD patients but not in healthy controls. Cortisol levels were not affected by exposure neither in patients nor in controls, but overall cortisol levels of OCD patients were increased compared to controls. In conclusion, our data suggests that symptom provocation in OCD patients with contamination fear is accompanied by alterations in the immune and neuroendocrine systems but does not affect cortisol levels.

89: Journal of immunology (Baltimore, Md. : 1950), 2009 Dec 30, 9(1)
Essential Roles of IL-6 Trans-Signaling in Colonic Epithelial Cells, Induced by the IL-6/Soluble-IL-6 Receptor Derived from Lamina Propria Macrophages, on the Development of Colitis-Associated Premalignant Cancer in a Murine Model.

[Abstract]Activation of the IL-6/Stat3 via IL-6 trans-signaling plays an important role in the pathogenesis of inflammatory bowel disease. Colitis-associated cancer (CAC) is a large bowel cancer and occurs with long-standing inflammatory bowel disease. The role of the IL-6/Stat3 in the development of CAC has not been fully understood. We investigate whether IL-6 trans-signaling contributes to the development of CAC using a mouse colitis-associated premalignant cancer (CApC) model. Chronic colitis (CC) was induced in BALB/c mice using dextran sodium sulfate. CApC was induced by dextran sodium sulfate treatment to CC-affected mice. IL-6 expression was determined by quantitative RT-PCR and immunofluorescence staining in colon. Phospho-Stat3 expression was examined by Western blotting and immunofluorescence analysis. The expression of IL-6 receptors (i.e., the IL-6R alpha-chain and gp130) and tumor necrosis factor-alpha converting enzyme in the colon was examined by laser-capture microdissection and immunofluorescence staining. Soluble IL-6Ralpha (sIL-6Ralpha) was examined by Western blotting of epithelial cell-depleted colonic tissues. We also investigated whether a soluble gp130-Fc fusion protein could prevent CApC. IL-6 expression was increased in the colon of CC- and CApC-affected mice and was restricted to lamina propria-macrophages. The expression of IL-6Ralpha and tumor necrosis factor-alpha converting enzyme was increased in the lamina propria CD11b-macrophages of CC-affected mice. sIL-6Ralpha expression was also increased in these tissues. Reduced levels of IL-6Ralpha generation were observed in the colonic epithelial cells of CC- and CApC-affected mice and were associated with the increased expression of gp130 and phospho-Stat3. Treatment with soluble gp130Fc significantly reduced the CApC. IL-6 trans-signaling in epithelial cells induced by macrophage-derived IL-6/sIL-6Ralpha plays a crucial role in the development of CAC.

90: Journal of immunology (Baltimore, Md. : 1950), 2009 Dec 30, 9(1)
Autoimmune Disease in Lyn-Deficient Mice Is Dependent on an Inflammatory Environment Established by IL-6.

[Abstract]Lyn-deficient mice develop Ab-mediated autoimmune disease resembling systemic lupus erythematosus where hyperactive B cells are major contributors to pathology. In this study, we show that an inflammatory environment is established in Lyn(-/-) mice that perturbs several immune cell compartments and drives autoimmune disease. Lyn(-/-) leukocytes, notably B cells, are able to produce IL-6, which facilitates hyperactivation of B and T cells, enhanced myelopoiesis, splenomegaly, and, ultimately, generation of pathogenic autoreactive Abs. Lyn(-/-) dendritic cells show increased maturation, but this phenotype is independent of autoimmunity as it is reiterated in B cell-deficient Lyn(-/-) mice. Genetic deletion of IL-6 on a Lyn-deficient background does not alter B cell development, plasma cell accumulation, or dendritic cell hypermaturation, suggesting that these characteristics are intrinsic to the loss of Lyn. However, hyperactivation of B and T cell compartments, extramedullary hematopoiesis, expansion of the myeloid lineage and autoimmune disease are all ameliorated in Lyn(-/-)IL-6(-/-) mice. Importantly, our studies show that although Lyn(-/-) B cells may be autoreactive, it is the IL-6-dependent inflammatory environment they engender that dictates their disease-causing potential. These findings improve our understanding of the mode of action of anti-IL-6 and B cell-directed therapies in autoimmune and inflammatory disease treatment.

91: International immunology, 2009 Dec 30, 9(1)
IL-6 positively regulates Foxp3+CD8+ T cells in vivo.

[Abstract]Although recent studies have identified regulatory roles for Foxp3(+)CD8(+) T cells, the mechanisms that induce their development and underlie their functions in vivo have not been elucidated. Here, we show that IL-6 positively regulates the Foxp3(+)CD8(+) T-cell development and function. The Foxp3(+)CD8(+) T cells that differentiated in vitro in the presence of IL-6 suppressed autoimmune colitis and arthritis in vivo. Moreover, Foxp3(+)CD8(+) T cells that developed in vivo in the presence of enhanced IL-6 signaling suppressed the development of a spontaneous T(h)17 cell-mediated autoimmune arthritis. Thus, we concluded that Foxp3(+)CD8(+) T cells develop in response to IL-6 and regulate chronic inflammation in T(h)17 cell-mediated F759 autoimmune arthritis. These results suggested that Foxp3(+)CD8(+) T cells may develop in response to IL-6 under certain inflammatory conditions in vivo and may regulate some other chronic inflammation diseases.

92: Diabetologia, 2010 Mar, 53(3)
IL6 as a mediator of insulin resistance: fat or fiction?

[Abstract]

93: Carcinogenesis, 2009 Dec 4, 217(1-2)
PTGS2 and IL6 Genetic Variation and Risk of Breast and Prostate Cancer: results from the Breast and Prostate Cancer Cohort Consortium (BPC3).

[Abstract]Genes involved in the inflammation pathway have been associated with cancer risk. Genetic variants in the interleukin-6 (IL6) and prostaglandin-endoperoxide synthase-2 (PTGS2, encoding for the COX-2 enzyme) genes, in particular, have been related to several cancer types, including breast and prostate cancers. We conducted a study within the Breast and Prostate Cancer Cohort Consortium (BPC3) to examine the association between IL6 and PTGS2 polymorphisms and breast and prostate cancer risk. Twenty-seven polymorphisms, selected by pairwise tagging, were genotyped on 6,292 breast cancer cases and 8,135 matched controls and 8,008 prostate cancer cases and 8,604 matched controls. The large sample sizes and comprehensive SNP tagging in this study gave us excellent power to detect modest effects for common variants. After adjustment for multiple testing, none of the associations examined remained statistically significant at P = 0.01. In analyses not adjusted for multiple testing, one IL6 polymorphism (rs6949149) was marginally associated with breast cancer risk (TT vs. GG, OR: 1.32; 99% CI: 1.00-1.74, P(trend)=0.003) and two were marginally associated with prostate cancer risk (rs6969502-AA versus rs6969502-GG, OR: 0.87, 99% CI: 0.75-1.02; P(trend) = 0.002 and rs7805828-AA vs. rs7805828-GG, OR: 1.11, 99% CI: 0.99-1.26; P(trend) = 0.007). An increase in breast cancer risk was observed for the PTGS2 polymorphism rs7550380 (TT vs. GG, OR: 1.38, 99% CI: 1.04-1.83). No association was observed between PTGS2 polymorphisms and prostate cancer risk. In conclusion, common genetic variation in these two genes might play at best a limited role in breast and prostate cancers.

94: Journal of comparative pathology, 2009 Dec 1, 119(12)
Lymphocyte Infiltration, Expression of Interleukin (IL) -1, IL-6 and Expression of Mutated Breast Cancer Susceptibility Gene-1 Correlate with Malignancy of Canine Mammary Tumours.

[Abstract]Malignant tumours are often associated with a relatively high number of tumour-infiltrating lymphocytes (TILs) and associated local cytokine production and these factors are thought to play a role in tumour progression. These aspects of tumour microenvironment have not been studied in canine mammary gland tumours (MGTs). The present study investigates TILs and the presence of related cytokines, as well as the expression of breast cancer susceptibility gene-1 (BRCA1), in canine MGTs. Immunohistochemistry, immunoblotting and reverse transcriptase-polymerase chain reaction were performed to evaluate these parameters. Three times as many T lymphocytes as B cells infiltrated canine MGTs. A correlation was found between expression of interleukin (IL)-1 and IL-6 and metastasis. There was an association between the expression of TILs, cytokines and mutation of BRCA1, suggesting that all of these factors may play a role in tumour progression.

95: Proceedings of the National Academy of Sciences of the United States of America, 2009 Dec 1, 60(6)
The nuclear receptor ROR{alpha} exerts a bi-directional regulation of IL-6 in resting and reactive astrocytes.

[Abstract]Astrocytes and one of their products, IL-6, not only support neurons but also mediate inflammation in the brain. Retinoid-related orphan receptor-alpha (RORalpha) transcription factor has related roles, being neuro-protective and, in peripheral tissues, anti-inflammatory. We examined the relation of RORalpha to astrocytes and IL-6 using normal and RORalpha loss-of-function mutant mice. We have shown RORalpha expression in astrocytes and its up-regulation by pro-inflammatory cytokines. We have also demonstrated that RORalpha directly trans-activates the Il-6 gene. We suggest that this direct control is necessary to maintain IL-6 basal level in the brain and may be a link between the neuro-supportive roles of RORalpha, IL-6, and astrocytes. Furthermore, after inflammatory stimulation, the absence of RORalpha results in excessive IL-6 up-regulation, indicating that RORalpha exerts an indirect repression probably via the inhibition of the NF-kappaB signaling. Thus, our findings indicate that RORalpha is a pluripotent molecular player in constitutive and adaptive astrocyte physiology.

96: The Journal of rheumatology, 2009 Dec 1, 6(4)
Interleukin 6 (IL-6) Deficiency Delays Lupus Nephritis in MRL-Faslpr Mice: The IL-6 Pathway as a New Therapeutic Target in Treatment of Autoimmune Kidney Disease in Systemic Lupus Erythematosus.

[Abstract]OBJECTIVE: To investigate the pathophysiological effect of interleukin 6 (IL-6) on lupus nephritis in MRL-Fas(lpr) mice. METHODS: We generated IL-6-deficient MRL-Fas(lpr) mice using a backcross/intercross breeding scheme. Renal pathology was evaluated using immunohistochemistry detection for macrophages, lymphocytes, vascular cell adhesion molecule-1 (VCAM-1), and TUNEL (terminal deoxynucleotide transferase-mediated dUTP nick end-labeling) for apoptototic cells, and renal IgG and C3 deposition by immunofluorescence staining. Expression of inflammatory markers in the spleen was analyzed by quantitative real-time reverse transcription-polymerase chain reaction. Serum cytokine concentrations were detected by FACS analysis. RESULTS: IL-6 deficiency was highly effective in prolonging survival and ameliorating the clinical, immunological, and histological indicators of murine systemic lupus erythematosus. During the study period of 6 months, MRL-Fas(lpr) IL-6 -/- mice showed delayed onset of proteinuria and hematuria compared to IL-6-intact control mice. Survival rate was 100% in IL-6-deficient MRL-Fas(lpr) mice and 25% in the control group at 6 months of age. The absence of IL-6 resulted in significant reduction of infiltrating macrophages in the kidney (p < 0.05), a decrease in renal IgG and C3 deposition, and a reduction of CD4+ and CD8+ lymphocytes. The parenchymal adhesion molecule VCAM-1 was found to be downregulated in kidneys of MRL-Fas(lpr) IL-6 -/- compared to IL-6-intact mice. We found elevated serum levels of IL-10 and interferon-gamma in IL-6-deficient mice, while splenic mRNA showed an overall downregulation of immunoregulatory genes. CONCLUSION: IL-6 is a strong promoter of lupus nephritis and may be a promising new therapeutic target in the treatment of human lupus nephritis.

97: Journal of cellular physiology, 2009 Nov 30, 55(5-6)
Effect of arachidonic acid on hypoxia-induced IL-6 production in mouse ES cells: Involvement of MAPKs, NF-kappaB, and HIF-1alpha.

[Abstract]This study examined the role of arachidonic acid (AA) in hypoxia-induced production of interleukin (IL)-6 and its related signaling pathways in mouse embryonic stem (ES) cells. Hypoxia with AA induced IL-6 production, which was mediated by reactive oxygen species (ROS). In addition, hypoxia increased the levels of p38 mitogen-activated protein kinases (MAPKs) and stress-activated protein kinase/c-jun NH(2)-terminal kinase (SAPK/JNK) phosphorylation, which were blocked by antioxidant (vitamin C). Inhibition of p38 MAPK and SAPK/JNK blocked hypoxia- or hypoxia with AA-induced nuclear factor-kappa B (NF-kappaB) activation. Furthermore, hypoxia-induced increase in hypoxia-inducible factor-1alpha (HIF-1alpha) expression was regulated by NF-kappaB activation. Consequently, the increased HIF-1alpha expression induced activation of matrix metalloproteinase (MMP)-2 and MMP-9. The expression of each signaling molecule stimulated an increase in IL-6 production that was greater in hypoxic conditions with AA than with hypoxia alone. Finally, inhibition of IL-6 production using IL-6 antibody or soluble IL-6 receptor attenuated the hypoxia-induced increases in DNA synthesis of mouse ES cells. In conclusion, AA potentiates hypoxia-induced IL-6 production through the MAPKs, NF-kappaB, and HIF-1alpha pathways in mouse ES cells. J. Cell. Physiol. (c) 2009 Wiley-Liss, Inc.

98: Placenta, 2009 Nov 28, 55(5-6)
IL-6, TNFalpha and TGFbeta Promote Nonapoptotic Trophoblast Deportation and Subsequently Causes Endothelial Cell Activation.

[Abstract]Preeclampsia is a complex disease of pregnancy with both feto-placental and maternal factors contributing to its pathogenesis. Failed transformation of the uterine spiral arteries leading to release of ischemic placental factors into the maternal circulation is thought to be the initial step in triggering preeclampsia. One placental factor associated with preeclampsia is necrotic trophoblastic debris that is deported in the maternal blood. The deported material ranges from multinucleated syncytial knots to nano-meter scale exosomes. Increasingly, it is being questioned whether failed transformation of the spiral arteries with subsequent placental ischemia is either necessary, or adequate, to explain the genesis of preeclampsia. In clinically established preeclampsia, maternal circulating levels of cytokines, such as TGFbeta, IL-6 and TNFalpha, are reported to be elevated. This study investigates whether cytokines can increase the shedding of necrotic material from the placenta. To investigate this question, placental explants were treated with nine cytokines which resulted in significantly increased amounts of trophoblasts being shed from explants treated with IL-6, TGFbeta-1 or TNFalpha but not the other cytokines. Trophoblasts shed from explants treated with IL-6, or TGFbeta-1 demonstrated a significant reduction in the activities of caspases while exposing endothelial cells to trophoblasts shed from explants treated with IL-6, TGF beta1 or TNFalpha resulted in endothelial cell activation. These results suggest that some cytokines can induce excess and/or aberrant death (necrotic or aponecrotic) trophoblast death. If reflected in vivo this might explain, at least in part, how some cytokines could affect trophoblast shedding/deportation and contribute to the pathogenesis of preeclampsia.

99: Human molecular genetics, 2009 Nov 26, 55(5)
An integrated expression phenotype mapping approach defines common variants in LEP, ALOX15 and CAPNS1 associated with induction of IL-6.

[Abstract]Interleukin-6 (IL-6) is an important modulator of inflammation and immunity whose dysregulation is associated with a number of disease states. There is evidence of significant heritability in inter-individual variation in IL6 gene expression but the genetic variants responsible for this remain to be defined. We adopted a combined approach of mapping protein and expression quantitative trait loci in peripheral blood mononuclear cells using high density SNP typing for approximately 2000 loci implicated in cardiovascular, metabolic and inflammatory syndromes to show that common SNP markers and haplotypes of LEP (encoding leptin) associate with a 1.7 to 2-fold higher level of lipopolysaccharide induced IL-6 expression. We subsequently demonstrate that basal leptin expression significantly correlates with lipopolysaccharide induced IL-6 expression and that the same variants at LEP which associate with IL-6 expression are also major determinants of leptin expression in these cells. We find that variation involving two other genomic regions, CAPNS1 (encoding calpain small subunit 1) and ALOX15 (encoding arachidonate 15-lipoxygenase), show significant association with IL-6 expression. Whilst this may be a subset of all such trans-acting effects, we find the same ALOX15 variants are associated with induced expression of tumour necrosis factor (TNF) and interleukin-1beta (IL-1B) consistent with a broader role in acute inflammation for ALOX15. This study provides evidence of novel genetic determinants of IL-6 production with implications for understanding susceptibility to inflammatory disease processes and insight into cross talk between metabolic and inflammatory pathways. It also provides proof of concept for use of an integrated expression phenotype mapping approach.

100: Systems biology in reproductive medicine, 2009 Dec, 55(5)
Response of IGF and IL-6 to Ovarian Stimulation in PCOS and Normal Women.

[Abstract]The objective of the present study was to investigate the response patterns of insulin-like growth factors (IGFs) and interleukin-6 (IL-6) to ovarian stimulation within 24 h in patients with polycystic ovary syndrome (PCOS) in comparison with normally ovulating women. This controlled prospective clinical study involved 60 women who attended an infertility clinic. For the induction of the ovarian stimulation, fifty-two patients with PCOS and eight control cases were injected with human menopause gonadotropin (hMG) and human chorionic gonadotropin (hCG) during the early follicular phase of the natural or induced menstrual cycle. The blood was sampled before (0h) and 6, 12, 18, and 24 h after the stimulation. Serum levels of estradiol (E2), IGF-I, IGF-II and IL-6 were measured by radioimmunoassay. A significant decrease in serum IGF-II at 12 h was observed after a mixture of hMG and hCG was administered in patients with polycystic ovaries (PCO) including the typical PCOS group and the PCO + OA group (accumulated p < 0.05), while normal women presented a slight decrease (accumulated p < 0.1) 18h after the stimulation. Moreover, all the groups had similar serum levels of IL-6 and IGF-I at all time points. An increase in serum E2 occurred coincident with a decrease in IGF-II in all the groups except the ovarian hyperandrogenism patients (HA + OA group). Serum IGF-II levels, which appeared to be negatively correlated with elevated E2, statistically decreased in PCO patients early after hMG and hCG administration when monitored for 24 h, while no such changes were observed in IGF-I and IL-6.

101: PloS one, 2009, 4(11)
IL-6 deficiency attenuates murine diet-induced non-alcoholic steatohepatitis.

[Abstract]BACKGROUND: The role of inflammation in the pathogenesis of non-alcoholic steatohepatitis (NASH), a common cause of liver disease, is still poorly understood. This study aimed at assessing the involvement of a major inflammatory cytokine, IL-6, in NASH. MATERIALS AND METHODS: Steatohepatitis was induced by feeding wild-type or IL-6(-/-) mice for 5 weeks with a methionine and choline-deficient (MCD) diet. RESULTS: Whereas MCD diet-induced weight loss and decreases in serum glucose, cholesterol and triglyceride levels were similar in both genotypes, serum alanine aminotransferase was less elevated in IL-6(-/-) mice than in wild-type animals. Despite having a comparable liver steatosis score, IL-6-deficient mice exhibited less lobular inflammation than their wild-type littermates. Liver gene expression of TGF-beta and MCP-1 was also strongly attenuated in mutant mice; a more modest reduction was observed for PPAR-gamma and F4/80 transcripts as well as proteins. Chromatographic analysis of liver lipids demonstrated that MCD diet induced in normal and mutant mice a similar decrease in the ratio of phosphatidylcholine to phosphatidylethanolamine. However, the diet-induced increase in the levels of sphingomyelin and ceramide was less important in IL-6(-/-) mice. CONCLUSION: Altogether, these results indicate that IL-6 deficiency does not block the development of NASH; yet, IL-6 plays a critical role in the accompanying liver inflammation.

102: Journal of pediatric gastroenterology and nutrition, 2009 Nov 17, 4(11)
Early-onset Crohn Disease Is Associated With Male Sex and a Polymorphism in the IL-6 Promoter.

[Abstract]AIMS:: Pediatric onset of Crohn disease (CD) is characterized by male sex predominance while adult-onset disease demonstrates female sex predominance. It has been postulated that this phenomenon may be genetically determined or due to an effect of estrogen on age of onset. Interleukin (IL)-6 modulates the TH17 pathway, and the IL-6 promoter is modulated by estrogen, possibly linking genetically determined inflammation and the presence of estrogen. The aim of our study was to investigate whether differences in IL-6 promoter genotype could explain male sex in earlier disease onset. PATIENTS AND METHODS:: We genotyped 333 patients with CD and 100 controls, 162 pediatric-onset patients (age of onset 18 years and younger) for the IL-6-174 polymorphic site. Genotype, sex, and age of onset were compared. RESULTS:: Males with IL-6-174GG genotype (the wild-type allele) had an increased risk for a younger age of onset compared to males with IL-6-174GC or CC genotype (G --> C genotype), hazard ratio (HR) 1.49, P = 0.02, 95% confidence interval (CI) 1.07-2.09. Females with GG genotype were not found to have an increased risk for a younger age of onset compared with females with G --> C genotype, HR 1.01, P = 0.96, 95% CI 0.72-1.41. CONCLUSIONS:: Males with IL-6-174GG genotype are prone to develop CD at a younger age than males with the IL-6-174G --> C genotype. Our study suggests that age of onset may be modified by the IL-6-174GG genotype and this modification is sex dependent. This may be due to increased transcription of IL-6, an effect that may be repressed by estrogen in females.

103: Clinical cancer research : an official journal of the American Association for Cancer Research, 2009 Nov 24, 55(5)
A High-Affinity Fully Human Anti-IL-6 mAb, 1339, for the Treatment of Multiple Myeloma.

[Abstract]PURPOSE: We investigated the in vitro and in vivo anti-multiple myeloma activity of monoclonal antibody (mAb) 1339, a high-affinity fully humanized anti-interleukin 6 mAb (immunoglobulin G1), alone and in combination with conventional and novel anti-multiple myeloma agents, as well as its effect on bone turnover. EXPERIMENTAL DESIGN: We examined the growth inhibitory effect of 1339 against multiple myeloma cell lines in the absence and in the presence of bone marrow stromal cells, alone or in combination with dexamethasone, bortezomib, perifosine, and Revlimid. Using the severe combined immunodeficient (SCID)-hu murine model of multiple myeloma, we also examined the effect of 1339 on multiple myeloma cell growth and multiple myeloma bone disease. RESULTS: mAb 1339 significantly inhibited growth of multiple myeloma cell in the presence of bone marrow stromal cell in vitro, associated with inhibition of phosphorylation of signal transducer and activator of transcription 3, extracellular signal-regulated kinase 1/2, and Akt. In addition, mAb 1339 enhanced cytotoxicity induced by dexamethasone, as well as bortezomib, lenalidomide, and perifosine, in a synergistic fashion. Importantly mAb 1339 significantly enhanced growth inhibitory effects of dexamethasone in vivo in SCID-hu mouse model of multiple myeloma. mAb 1339 treatment also resulted in inhibition of osteoclastogenesis in vitro and bone remodeling in SCID-hu model. CONCLUSIONS: Our data confirm in vitro and in vivo anti-multiple myeloma activity of, as well as inhibition of bone turnover by, fully humanized mAb 1339, as a single agent and in combination with conventional and novel agents, providing a rationale for its clinical evaluation in multiple myeloma. (Clin Cancer Res 2009;15(23):7144-52).

104: Gut, 2009 Nov 18, 60(6)
Disease-Related Expression of the IL-6 / STAT3 / SOCS3 Signaling Pathway in Ulcerative Colitis and Ulcerative Colitis-Related Carcinogenesis.

[Abstract]Background/ AIMS: Mouse models showed that IL-6 stimulates survival, proliferation and progression to cancer of intestinal epithelial cells via activation of STAT3. We investigated the expression of IL-6 / p-STAT3 / SOCS3 in biopsies from patients with ulcerative colitis (UC) and UC related-colorectal cancer (CRC) progression. METHODS: Biopsies from patients with inactive UC (n=18), active UC (n=28), UC with low-grade dysplasia (LGD) (n=9), UC with high-grade dysplasia (HGD) (n=7), UC-CRC (n=11) and sporadic CRC (n=14) were included. Biopsies (n=9) from patients without colonic abnormalities served as control. The protein expression of IL-6, p-STAT3 and SOCS3 was determined immunohistochemically. RESULTS: Patients with active UC had significantly more IL-6 and p-STAT3 positive epithelial cells than both inactive UC patients and controls (strong positive IL-6: 53.6%, 11.1% and 0% respectively; p-STAT3: 64.3%, 22.2% and 11.1% respectively; all p105: Modern rheumatology / the Japan Rheumatism Association, 2009 Nov 14, 125(10)
Cyclic AMP response element-binding protein is implicated in IL-6 production from arthritic synovial cells.

[Abstract]Overproduction of interleukin (IL)-6 from synovial cells is critically involved in the pathogenesis of rheumatoid arthritis (RA). Cyclic adenosine monophosphate (AMP) response element-binding protein (CREB), a leucine zipper transcription factor, is expressed at a high level in synovial cells of patients with RA. Although CREB transactivates IL-6 expression in vascular smooth muscle cells, the relation between CREB expression and IL-6 production from arthritic synovial cells remains unclear. In this study, to determine whether CREB is implicated in IL-6 production from arthritic synovial cells, a dominant negative molecule of activation transcription factor 1 (ATF-1) was transfected into synovial cells obtained from arthritic joints of env-pX rats. These transgenic rats carrying the env-pX gene of human T-cell leukemia virus type-1 develop destructive arthritis with high titers of serum rheumatoid factor and are thus regarded as a suitable model of RA. The dominant negative ATF-1 (ATF-1DN) constitutes a heterodimer with CREB and inhibits CREB function, as CREB/ATF-1DN heterodimers no longer bind to the target sequence of CREB. We showed that transfection of ATF-1DN significantly reduced IL-6 production from arthritic synovial cells. These findings suggest that CREB is implicated in IL-6 production from synovial cells and plays an important role in RA pathogenesis.

106: Biochemical and biophysical research communications, 2009 Nov 14, 125(10)
The association of functional polymorphisms of IL-6 gene promoter with ischemic stroke: Analysis in two Chinese populations.

[Abstract]Polymorphisms of G-572C and G-174C in the interleukin-6 (IL-6) promoter can affect both the transcription and secretion of IL-6 and may be involved in inflammation related to and the pathogenesis of ischemic stroke (IS). However, whether IL-6 polymorphisms are indeed risk factors for IS remains controversial. We recruited 748 Chinese IS patients diagnosed by magnetic resonance imaging (MRI) within 24 hours of symptom onset and 748 normal healthy controls from two ethnic populations and performed two case-control studies in order to assess the nature of the polymorphisms of IL-6 and any links with IS. Common polymorphic loci in the IL-6 gene promoter were determined by TaqMan SNP genotyping assays. Multivariate logistic regression analysis was used to examine the association between IL-6 genotypes and a diagnosis of IS. We found that the C allele frequency at the -174 promoter region of IL-6 was extremely low in both IS patients and controls in both ethnic groups. The G allele of the promoter single nucleotide polymorphism (SNP) G-572C was more common in IS subjects than controls (P=0.004, corrected for multiple testing) in the Han population but not in the Uyghur population. GC carriage therefore increased the risk of IS in the Han ethnic group (OR 1.45, 95% CI 1.13 to 1.86). In addition, the differences in GG and GC frequency between the two ethnic populations were significant. The C allele frequency at the -174 promoter region of IL-6 was rare in Chinese IS patients and controls from either ethnic group. We conclude that IL-6-572GC may be an independent risk factor for IS in the Chinese Han population.

107: Neuroscience letters, 2009 Nov 12, 311(1-2)
Genetic Variants of IL-6 and Its Receptor Are Not Associated with Schizophrenia in Taiwan.

[Abstract]The pathophysiological process of schizophrenia is still unclear. The levels of interleukine-6 (IL-6) and its receptor, soluble IL-6R, have been reported to be elevated in the plasma and cerebrospinal fluid of schizophrenic patients. In this study, we tested the association of genetic variants of IL-6 and IL-6R with schizophrenia. Genotyping of three single nucleotide polymorphisms (SNP) for each IL-6 (IL-6-1, IL-6-2, and IL-6-3) and IL-6R (rs4845617=IL-6R1, rs4553185= IL-6R2, and rs4379670= IL-6R3) gene were performed in 100 patients with schizophrenia and 113 normal controls. The polymorphisms of IL-6R2 were genotyped using Tetra-primer ARMS PCR. IL-6R3 polymorphisms were genotyped using restriction fragment length polymorphism (RFLP) with Apo I enzyme as the restriction enzyme. All other polymorphisms were genotyped using the direct sequencing method. We found a di-nucleotide haplotype block and a tri-nucleotide haplotype block in the genes of IL-6 and IL-6R, respectively. All six SNPs and their haplotypes failed to show a significant association with schizophrenia. The IL-6-2 SNP showed a nominally significant association with the positive symptoms of schizophrenia (p=0.0472). We conclude that the genetic variants of IL-6 and IL-6R are not associated with schizophrenia. In order to verify this result, further study using a larger sample size and exploring the association between the genotype of IL-6-2 and plasma level of IL-6 is recommended.

108: Journal of immunotoxicology, 2009 Dec, 6(4)
The cannabinoid R(+)methanandamide induces IL-6 secretion by prostate cancer PC3 cells.

[Abstract]In the present study, we have investigated the effect of the cannabinoid R(+)methanandamide (MET) in the androgen-resistant prostate cancer PC3 cells. MET induced a dose-dependent decrease in PC3 cell viability as well as a dose-dependent increase in the secretion of the cytokine IL-6. Looking deeper into the mechanisms involved, we found that MET-induced de novo synthesis of the lipid mediator ceramide that was blocked by the ceramide synthase inhibitor Fumonisin B1. Pre-incubation of cells with the cannabinoid receptor CB2 antagonist SR 144528 (SR2), but not the CB1 antagonist Rimonabant or the TRPV1 antagonist capsazepine, partially prevented the anti-proliferative effect, the ceramide accumulation, and the IL-6-induced secretion, suggesting a CB2 receptor-dependent mechanism. Fumonisin B1 did not have any effect in the IL-6 secretion increase induced by MET. However, even an incomplete down-regulation of (i.e., not a total silencing of) ceramide kinase expression by specific siRNA prevented the MET-induced IL-6 secretion. These results suggest that MET regulates ceramide metabolism in prostate PC3 cells which is involved in cell death as well as in IL-6 secretion. Our findings also suggest that CB2 agonists may offer a novel approach in the treatment of prostate cancer by decreasing cancer epithelial cell proliferation. However, the interaction of prostate cancer cells with their surrounding, and in particular with the immune system in vivo, needs to be further explored.

109: American journal of physiology. Regulatory, integrative and comparative physiology, 2009 Nov 11, 311(1-2)
IL-6 microinjected into the nucleus tractus solitarii attenuates cardiac baroreceptor reflex function in rats.

[Abstract]Recent gene array and molecular studies have suggested that an abnormal gene expression profile of interleukin-6 (IL-6) in the nucleus tractus solitarii (NTS), a pivotal region for regulating arterial pressure, may be related to the development of neurogenic hypertension. However, the precise functional role of IL-6 in the NTS remains unknown. In the present study, we have tested whether IL-6 affects cardiovascular control at the level of the NTS. IL-6 (1, 10, and 100 fmol) was microinjected into the NTS of Wistar rats (280-350g) under urethane-anesthesia. Although the baseline levels of arterial pressure and heart rate did not change following IL-6 injections, the cardiac baroreflex in response to increased arterial pressure was dose-dependently attenuated. In addition, IL-6 (100 fmol) microinjections also attenuated L-glutamate induced bradycardia at the level of the NTS. Immunohistochemical detection of IL-6 in na?ve rats demonstrated that it was predominantly observed in neurons within the brainstem including the NTS. These findings suggest that IL-6 within the NTS may play an important role for regulating cardiovascular control via modulation of input signals from baroreceptor afferents. Whether the abnormal gene expression of IL-6 in the NTS is associated in a causal way with hypertension remains to be resolved. Key words: IL-6, nucleus tractus solitarii, blood pressure, baroreceptor reflex.

110: Journal of biomedical materials research. Part B, Applied biomaterials, 2009 Nov 10, 4(11)
IL-6 adsorption dynamics in hemoadsorption beads studied using confocal laser scanning microscopy.

[Abstract]Sepsis is characterized by a systemic inflammatory response caused by infection, and can result in organ failure and death. Removal of inflammatory mediators such as cytokines from the circulating blood is a promising treatment for severe sepsis. We are developing an extracorporeal hemoadsorption device to remove cytokines from the blood using biocompatible, polymer sorbent beads. In this study, we used confocal laser scanning microscopy (CLSM) to directly examine adsorption dynamics of a cytokine (IL-6) within hemoadsorption beads. Fluorescently labeled IL-6 was incubated with sorbent particles, and CLSM was used to quantify spatial adsorption profiles of IL-6 within the sorbent matrix. IL-6 adsorption was limited to the outer 15 mum of the sorbent particle over a relevant clinical time period, and intraparticle adsorption dynamics was modeled using classical adsorption/diffusion mechanisms. A single model parameter, alpha = q(max) K/D, was estimated by fitting CLSM intensity profiles to our mathematical model, where q(max) and K are Langmuir adsorption isotherm parameters, and D is the effective diffusion coefficient of IL-6 within the sorbent matrix. Given the large diameter of our sorbent beads (450 mum), less than 20% of available sorbent surface area participates in cytokine adsorption. Development of smaller beads may accelerate cytokine adsorption by maximizing available surface area per bead mass. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.

111: Journal of proteome research, 2009 Nov 10, 4(11)
Quantitative Phosphoproteomic Analysis of the STAT3/IL-6/HIF1alpha Signaling Network: An Initial Study in GSC11 Glioblastoma Stem Cells.

[Abstract]Initiation and maintenance of several cancers including glioblastoma (GBM) may be driven by a small subset of cells called cancer stem cells (CSCs). CSCs may provide a repository of cells in tumor cell populations that are refractory to chemotherapeutic agents developed for the treatment of tumors. STAT3 is a key transcription factor associated with regulation of multiple stem cell types. Recently, a novel autocrine loop (IL-6/STAT3/HIF1alpha) has been observed in multiple tumor types (pancreatic, prostate, lung and colon). The objective of this study was to probe perturbations of this loop in a glioblastoma cancer stem cell line (GSC11) derived from a human tumor by use of a JAK2/STAT3 phosphorylation inhibitor (WP1193), IL-6 stimulation and hypoxia. A quantitative phosphoproteomic approach that employed phosphoprotein enrichment, chemical tagging with isobaric tags, phosphopeptide enrichment and tandem mass spectrometry in a high-resolution instrument was applied. A total of 3,414 proteins were identified in this study. A rapid Western blotting technique (< 1 hour) was used to confirm alterations in key protein expression and phosphorylation levels observed in the mass spectrometric experiments. About 10% of the phosphoproteins were linked to the IL-6 pathway and the majority of remaining proteins could be assigned to other interlinked networks. By multiple comparisons between the sample conditions, we observed expected changes and gained novel insights into the contribution of each factor to the IL6/STAT3/HIF1alpha autocrine loop and the CSC response to perturbations by hypoxia, inhibition of STAT3 phosphorylation and IL-6 stimulation.

112: Cell, 2009 Oct 28, 46(6)
An Epigenetic Switch Involving NF-kappaB, Lin28, Let-7 MicroRNA, and IL6 Links Inflammation to Cell Transformation.

[Abstract]Inflammation is linked clinically and epidemiologically to cancer, and NF-kappaB appears to play a causative role, but the mechanisms are poorly understood. We show that transient activation of Src oncoprotein can mediate an epigenetic switch from immortalized breast cells to a stably transformed line that forms self-renewing mammospheres that contain cancer stem cells. Src activation triggers an inflammatory response mediated by NF-kappaB that directly activates Lin28 transcription and rapidly reduces let-7 microRNA levels. Let-7 directly inhibits IL6 expression, resulting in higher levels of IL6 than achieved by NF-kappaB activation. IL6-mediated activation of the STAT3 transcription factor is necessary for transformation, and IL6 activates NF-kappaB, thereby completing a positive feedback loop. This regulatory circuit operates in other cancer cells lines, and its transcriptional signature is found in human cancer tissues. Thus, inflammation activates a positive feedback loop that maintains the epigenetic transformed state for many generations in the absence of the inducing signal.

113: Clinical immunology (Orlando, Fla.), 2009 Oct 22, 65(3)
Essential and synergistic roles of IL1 and IL6 in human Th17 differentiation directed by TLR ligand-activated dendritic cells.

[Abstract]Requirements for human Th17 differentiation in the context of activated dendritic cells (DCs) are still emerging. Here, we demonstrate that several Toll-like receptor (TLR) ligands, particularly LPS and a synthetic lipoprotein, activate human DCs to direct increased human Th17 differentiation. Based on neutralization studies, IL1, IL6, and TGFbeta contributed to human Th17 differentiation induced by LPS-activated DCs. Furthermore, TLR ligand-activated DCs produced high levels of IL6 and low levels of IL1beta. In an antigen presenting cell (APC)-free system, the minimum requirements identified for human Th17 differentiation from adult naive CD4(+) T cells, depleted of CD25(+) cells, were TGFbeta and high levels of IL1beta. However, in the presence of the physiologically low levels of IL1 such as those produced by DCs, both TGFbeta and IL6 were also essential. These results help to explain the conflicting reports in the literature on the roles of IL1 and IL6 on human Th17 differentiation.

114: Journal of science and medicine in sport / Sports Medicine Australia, 2009 Oct 21, 65(3)
The -174 G/C polymorphism of the IL6 gene is associated with elite power performance.

[Abstract]The -174 G/C polymorphism [rs1800795] of the IL6 gene is a candidate to explain individual variations in health and exercise related phenotypes. We compared -174 G/C genotypic and allelic frequencies in three groups of men of the same Caucasian (Spanish) descent: elite endurance athletes (cyclists, runners; n=100); elite power athletes (jumpers, throwers, sprinters; n=53) and non-athletic controls (n=100). The frequency of the GG genotype (P=0.030) and G allele (P=0.026) was higher in the power athletes group compared with the control group. The frequency of the GG genotype (P=0.033) and G allele (P=0.013) was also higher in the power athletes group compared with the endurance athletes group. The odds ratio of being a power athlete if the subject had the GG genotype (dominant model) was 2.471 (95% confidence interval: 1.242-4.915) compared to the control group or the endurance athlete group. We did not find differences between the control and endurance athlete groups. In summary, our findings suggest that the G allele of the IL6 -174 G/C polymorphism might favour sprint/power sports performance.

115: European journal of endocrinology / European Federation of Endocrine Societies, 2009 Oct 16, 65(3)
Insulin resistance in hyperthyroidism: the role of IL-6 and TNF{alpha}

[Abstract]Objective: Although insulin resistance is a common finding in hyperthyroidism, the implicated mechanisms are obscure. The aim of this study was to investigate whether IL-6 and TNFalpha are related to the development of insulin resistance in hyperthyroidism of non-autoimmune origin. Design and methods: A meal was given to ten hyperthyroid (HR) and ten euthyroid women (EU). Plasma samples were taken for 360min from the radial artery for measurements of glucose, insulin and non-esterified-fatty-acids (NEFA). IL-6 and TNFalpha were measured preprandially from the superficial epigastric vein and from the radial artery. Results: (1) In HR vs EU: (a) arterial glucose was similar (AUC(0-360)2087+/-57 vs 2010+/-43mM*min), but insulin was increased (AUC(0-360)17267+/-2447 vs 10331+/-666mU/l*min, p=0.01) (b) HOMA was increased (2.3+/-0.4 vs 1+/-0.1 kg/m2, p=0.007) (c) arterial NEFA were increased (AUC(0-360)136+/-18 vs 89+/-7mmol/l*min, p=0.03) (d) arterial IL-6 (2+/-0.3 vs 0.9+/-0.1pg/ml, p=0.0009) and TNFalpha (4.2+/-0.8 vs 1.5+/-0.2pg/ml, p=0.003) were increased (e) IL-6 production from the subcutaneous adipose tissue (AT) was increased (18+/-6 vs 5+/-1pg/min/100mltissue, p=0.04). (2) (a) subcutaneous venous IL-6 was positively associated with HOMA (beta-coefficient=1.7+/-0.7, p=0.049) (b) although TNFalpha was not produced by the subcutaneous AT, arterial TNFalpha was positively associated with NEFA (AUC(0-360)) (beta-coefficient=0.045+/-0.01, p=0.005). Conclusions: In hyperthyroidism: (1) glucose and lipid metabolism are resistant to insulin (2) subcutaneous AT releases IL-6 which could then act as an endocrine mediator of insulin resistance (3) although there is no net secretion of TNFalpha by the subcutaneous AT, increased systemic TNFalpha levels may be related to the development of insulin resistance in lipolysis.

116: Investigative ophthalmology & visual science, 2009 Oct 15, 65(3)
Role of IL-6 in Angiotensin II-induced Retinal Vascular Inflammation.

[Abstract]Purpose: Production of pro-inflammatory cytokines has been shown to play a critical role in a variety of retinal vascular diseases. Angiotensin II and VEGF have been implicated in the initiation of vascular inflammation and retinal vascular disease. However, detailed mechanisms of this process and interactions between inflammatory agonists and angiotensin II in promoting retinopathy are poorly understood. Here we investigate the role of interleukin-6 (IL-6) in angiotensin II-induced retinopathy. Methods: Rats, IL-6-deficient and wild-type mice were treated with angiotensin II or IL-6 and their retinas were analyzed for leukocyte adhesion or for the expression and localization of VEGF or IL-6. Leukocyte adhesion was assayed by conconavalin A labeling. Vascular density was determined by morphometric analysis. NADPH oxidase activity was assayed by dihydroethidium imaging of superoxide. Results: Intravitreal injection of angiotensin II caused increases in mRNA and protein for IL-6 and leukocyte adhesion to the retinal vessels. IL-6 protein was localized to CD11b-positive microglia and macrophage-like cells. Angiotensin II treatment stimulated increases in retinal levels of VEGF expression and NADPH oxidase activity, which were associated with increased surface area and remodeling of the retinal vessels. These effects were blocked by knocking out IL-6. Intravitreal IL-6 directly induced leukocyte adhesion in both wild-type and IL-6-deficient mice. Conclusion: These results indicate that IL-6 expression is required for angiotensin II-induced increases in retinal VEGF expression, leukostasis and vascular remodeling. These data suggest a critical role for IL-6 in mediating angiotensin II-induced retinal vascular inflammation and remodeling.

117: Shock (Augusta, Ga.), 2010 May, 33(5)
Lipoteichoic acid-induced TNF-alpha and IL-6 gene expressions and oxidative stress production in macrophages are suppressed by ketamine through downregulating Toll-like receptor 2-mediated activation oF ERK1/2 aND NFkappaB.

[Abstract]Lipoteichoic acid (LTA), a gram-positive bacterial outer membrane component, can cause septic shock. Our previous studies showed that ketamine has anti-inflammatory and antioxidant effects on gram-negative LPS-induced macrophage activation. In this study, we further evaluated the effects of ketamine on the regulation of LTA-induced TNF-alpha and IL-6 gene expressions and oxidative stress production in macrophages and its possible mechanisms. Exposure of macrophages to a therapeutic concentration of ketamine (100 microM) inhibited LTA-induced TNF-alpha and IL-6 expressions at protein or mRNA levels. In parallel, ketamine at 100 microM reduced LTA-stimulated phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Sequentially, ketamine reduced the LTA-triggered translocation of nuclear factor-kappaB (NFkappaB) from the cytoplasm to nuclei and its transactivation activity. Pretreatment with PD98059, an inhibitor of ERK, decreased LTA-enhanced NFkappaB activation and TNF-alpha and IL-6 mRNA syntheses. Cotreatment with ketamine and PD98059 synergistically suppressed the LTA-induced translocation and transactivation of NFkappaB and biosyntheses of TNF-alpha and IL-6 mRNA. Application of Toll-like receptor 2 (TLR2) small interfering RNA (si)RNA into macrophages decreased the levels of this receptor, and simultaneously ameliorated LTA-augmented NFkappaB transactivation and consequent production of TNF-alpha and IL-6 mRNA. Cotreatment with ketamine and TLR2 siRNA synergistically lowered TNF-alpha and IL-6 mRNA syntheses in LTA-activated macrophages. Ketamine and TLR2 siRNA could reduce the LTA-induced increases in production of nitrite and intracellular reactive oxygen species in macrophages, and their combination had better effects than a single exposure. Thus, this study shows that one possible mechanism involved in ketamine-induced inhibition of LTA-induced TNF-alpha and IL-6 gene expressions and oxidative stress production is through downregulating TLR2-mediated phosphorylation of ERK1/2 and the subsequent translocation and transactivation of NFkappaB.

118: Journal of immunology (Baltimore, Md. : 1950), 2009 Oct 15, 183(8)
Cutting Edge: Importance of IL-6 and cooperation between innate and adaptive immune receptors in cellular vaccination with B lymphocytes.

[Abstract]B lymphocytes are a potential alternative to dendritic cell immunotherapy, with the advantages of relative abundance in peripheral blood and the ability to function as APCs. Although B cells express multiple receptors that induce costimulatory molecules, B cell vaccine studies have focused primarily on CD40 stimulation. To optimize the potential efficacy of B cell vaccines (Bvac), we compared the capacity of differentially stimulated B cells to induce Ag-specific CD8(+) T cell responses in vivo. CD40- or TLR7-stimulated B cell APCs induced similar CD8(+) T cell responses, but costimulation through the BCR and TLR7 produced a more effective Bvac as measured by T cell stimulation and the protection of mice from an infectious pathogen. This increased effectiveness depended upon enhanced production of IL-6 by BCR plus TLR7-stimulated B cells. These findings reveal alternative stimulation strategies for the production of effective Bvac and identify a key role for IL-6 in B cell Ag presentation and cellular vaccines.

119: Journal of immunology (Baltimore, Md. : 1950), 2009 Oct 15, 183(8)
MAIL regulates human monocyte IL-6 production.

[Abstract]IL-6 is a pleiotropic cytokine implicated in the pathogenesis of disorders such as sepsis and cancer. We noted that human monocytes are excellent producers of IL-6 as compared with monocyte-derived macrophages. Because macrophages from molecule containing ankyrin repeats induced by LPS (MAIL) knockout animals have suppressed IL-6 production, we hypothesized that regulation of MAIL is key to IL-6 production in humans and may explain the differences between human monocytes and macrophages. To test this hypothesis fresh human monocytes and monocyte-derived macrophages were compared for MAIL expression in response to LPS. LPS-induced monocyte MAIL expression was highly inducible and transient. Importantly for our hypothesis MAIL protein expression was suppressed during differentiation of monocytes to macrophages. Of note, the human MAIL protein detected was the 80 kDa MAIL-L form and human MAIL showed nuclear localization. Human MAIL-L bound to p50 subunit of the NF-kappaB and increased IL-6 luciferase promoter activity in a cEBPbeta, NF-kappaB, and AP-1-dependent fashion. Like the differences in MAIL induction, monocytes produced 6-fold more IL-6 compared with macrophages (81.7 +/- 29.7 vs 12.6 +/- 6.8 ng/ml). Furthermore, suppression of MAIL by small interfering RNA decreased the production of IL-6 significantly in both THP-1 cells and in primary monocytes. Costimulation of monocytes with LPS and muramyl dipeptide induced an enhanced IL-6 response that was suppressed by siMAIL. Our data suggests that MAIL is a key regulator of IL-6 production in human monocytes and plays an important role in both TLR and NOD-like receptor ligand induced inflammation.

120: Molecular immunology, 2009 Dec, 47(2-3)
C/EBPzeta (CHOP/Gadd153) is a negative regulator of LPS-induced IL-6 expression in B cells.

[Abstract]C/EBPzeta was originally identified as a gene induced upon DNA damage and growth arrest. It has been shown to be involved in the cellular response to endoplasmic reticulum stress. Because of sequence divergence from other C/EBP family members in its DNA-binding domain and its consequent inability to bind the C/EBP consensus-binding motif, C/EBPzeta can act as a dominant negative inhibitor of other C/EBPs. C/EBP transactivators are essential to the expression of many proinflammatory cytokines and acute phase proteins, but a role for C/EBPzeta in regulating their expression has not been described. We found that expression of C/EBPzeta is induced in response to LPS treatment of B cells at both the mRNA and protein levels. Correlating with the highest levels of C/EBPzeta expression at 48h after LPS treatment, there is an increased association of C/EBPzeta with C/EBPbeta, and both the abundance of C/EBP DNA-binding species and IL-6 expression are downregulated. Furthermore, ectopic expression of C/EBPzeta inhibited C/EBPbeta-dependent IL-6 expression from both the endogenous IL-6 gene and an IL-6 promoter-reporter. These results suggest that C/EBPzeta functions as negative regulator of IL-6 expression in B cells and that it contributes to the transitory expression of IL-6 that is observed after LPS treatment.

121: Toxicology in vitro : an international journal published in association with BIBRA, 2010 Feb, 24(1)
Mechanisms involved in ultrafine carbon black-induced release of IL-6 from primary rat epithelial lung cells.

[Abstract]The aims of the present study were to establish to what extent IL-1, and intracellular pathways involving mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-kappaB), play a role in ultrafine particle-induced release of IL-6 by primary rat epithelial lung cells. Ultrafine carbon black (Printex 90) induced a concentration- and time-dependent increase in the release of IL-1alpha, IL-1beta and IL-6. The ultrafine carbon black-induced release of IL-6 was completely eliminated by an IL-1 receptor antagonist (IL-1ra). Cellular release of IL-1alpha, IL-1beta and IL-6 was significantly attenuated by curcumin and by inhibitors of the MAPKs ERK1/2 (PD98069), p38 (SB202190) and JNK (SP600125), whereas pyrrolidine dithiocarbamate (PDTC) attenuated the release of IL-6, but not of IL-1alpha and IL-1beta. The effects of curcumin and PDTC may indicate an involvement of NF-kappaB. Furthermore, ultrafine carbon black induced degradation of IkappaBalpha, used as an indicator of NF-kappaB activation, and induced phosphorylation of ERK1/2, p38 and JNK1/2. This degradation and phosphorylation was attenuated by IL-1ra. The present findings provide more insight into the largely unknown mechanisms involved in ultrafine particle-induced release of cytokines from lung cells. The findings suggest that ultrafine carbon black-induced release of IL-6 strongly depends on IL-1 and that activation of MAPKs and NF-kappaB is involved in this response.

122: Experimental dermatology, 2010 Aug, 19(8)
IL-6 Stimulates but is not essential for stratum corneum formation and permeability barrier development during gestation.

[Abstract]Please cite this paper as: IL-6 Stimulates but is not essential for stratum corneum formation and permeability barrier development during gestation. Experimental Dermatology 2010; 19: e31-e36. Abstract: The regulation of epidermal ontogenesis is a complex process. Previous studies have shown that cytokines (IL-1, TNFalpha and IL-6) regulate permeability barrier homeostasis in adult mice. Recently, we reported that IL-1 and TNFalpha accelerate stratum corneum (SC) formation and permeability barrier development in foetal rodents. Here, we determined whether IL-6 also regulates SC formation and permeability barrier development during late gestation. Using a rat skin explant model, we demonstrated that IL-6 accelerates permeability barrier formation in a time- and dose-dependent fashion. This acceleration of barrier formation is attributable to (a) accelerated lamellar membrane maturation, (b) formation of a multi-layer SC and (c) enhanced expression of epidermal differentiation markers. When comparing epidermis of IL-6-deficient (knockout mice) and wild-type foetal mice at days 16-18, we could not detect any abnormalities in either SC formation or the expression of differentiation markers in knockout (KO) mice. In parallel, the basal expression levels of IL-6 mRNA in epidermis and IL-6 protein in amniotic fluid were very low, with only a minimal change in IL-6 receptor mRNA levels in epidermis of days 16-22 foetal mice. These low IL-6 levels may account, at least in part, for the absence of epidermal abnormalities in IL-6 KO mice. In conclusion, exogenous IL-6 accelerates epidermal ontogenesis, but it is not essential for normal epidermal maturation.

123: American journal of physiology. Cell physiology, 2009 Nov, 297(5)
IL-6 stimulates system A amino acid transporter activity in trophoblast cells through STAT3 and increased expression of SNAT2.

[Abstract]Changes in placental nutrient transport are closely associated with abnormal fetal growth. However, the molecular mechanisms underlying the regulation of placental amino acid transporters are unknown. We demonstrate that physiological concentrations of the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha stimulate the activity of amino acid transporter system A, but not system L, in cultured human primary trophoblast cells. Both cytokines increased the gene and protein expression of the Na(+)-coupled neutral amino acid transporter (SNAT)2 isoform and upregulated SNAT1 protein expression. IL-6 increased Tyr705 phosphorylation of signal transducer and activator of transcription 3 (STAT3). In cells transfected with small interfering RNA (siRNA) targeting STAT3, the RNA and protein expression of SNAT2, but not SNAT1, was reduced and the stimulating effect of IL-6 on system A activity was abolished. Despite eliciting similar responses in amino acid transport activity and transporter expression, TNF-alpha effects on system A activity were not mediated through the JAK/STAT pathway. In conclusion, we have identified a novel regulatory pathway involving increased gene expression of the SNAT2 isoform mediated by a STAT-dependent pathway, which links IL-6 to increased activity of system A, a ubiquitously expressed transporter of neutral amino acids. From these new findings, we propose that upregulation of amino acid transporters by cytokines may contribute to increased placental nutrient transport and fetal overgrowth, which are commonly found in pregnancies complicated by maternal diabetes and obesity.

124: Immunobiology, 2010 Jun, 215(6)
IL-6-transfected tumor cells modulate the status of CD8(+) and CD4(+) T cells to control tumor growth.

[Abstract]IL-6 is a proinflammatory cytokine secreted by tumor cells and immune cells to affect the development of cancer. This study demonstrates the effects of tumor-derived IL-6 on the malignancy of tumor cells and tumor immunity. The tumor cell line, EG7, was transfected with a mammalian expression vector encoding the full length of murine IL-6 to mimic IL-6-secreting tumor cells. Two IL-6 transfectants with low and high IL-6 production were compared in vitro and in vivo. While the in vitro proliferation rates of both transfectants and the parental line were similar, high expression of IL-6 induced a significant reduction in tumor growth in vivo. Concomitantly, there was an increase in IFN-gamma positive tumor-infiltrating lymphocytes and a decrease in the suppressive CD4(+)CD25(+)FoxP3(+) population. These results demonstrate the direct effects of tumor-derived IL-6 on cancer development and the induction of tumor immunity.

125: Inflammation research : official journal of the European Histamine Research Society ... [et al.], 2010 Feb, 59(2)
Lycopene suppresses LPS-induced NO and IL-6 production by inhibiting the activation of ERK, p38MAPK, and NF-kappaB in macrophages.

[Abstract]BACKGROUND: Lycopene has antioxidant, anticancer, and anti-inflammatory effects with molecular mechanisms not fully identified. AIM AND METHODS: We investigated the effects of lycopene on the inflammatory responses to lipopolysaccharide (LPS) in RAW264.7 cells and the signal transduction pathways involved. RESULTS: Lycopene inhibited LPS-induced production of nitric oxide (NO) and interleukin-6 (IL-6) with decreased mRNAs of inducible nitric oxide synthase and IL-6 but had no effect on TNF-alpha. Further study showed that lycopene also inhibited LPS-induced IkappaB phosphorylation, IkappaB degradation, and NF-kappaB translocation. Moreover, lycopene blocked the phosphorylation of ERK1/2 and p38 MAP kinase but not c-Jun NH(2)-terminal kinase. To confirm the causal link between MAP kinase inhibition and its anti-inflammatory effects, we treated the cells with SB 203580 and U0126. These inhibitors significantly inhibited LPS-induced NO and IL-6 formation. CONCLUSION: Lycopene inhibits the inflammatory response of RAW 264.7 cells to LPS through inhibiting ERK/p38 MAP kinase and the NF-kappaB pathway.

126: Journal of reproductive immunology, 2009 Nov, 82(2)
IL-6 trans-signaling and the frequency of CD4+FOXP3+ cells in women with reproductive failure.

[Abstract]Pregnancy constitutes a major challenge to the maternal immune system, as it requires tolerance of paternal alloantigen. Maternal rejection of the fetus may develop when T regulatory (Treg) cells fail to control the balance between tolerance and immunity. Increasing evidence supports the role of IL-6 trans-signaling within T cells as a key pathway for blockade of the development of adaptive Treg cells. The present study investigated whether alteration of the components of the IL-6 trans-signaling might be a mechanism associated with modified immune responses in patients experiencing recurrent spontaneous abortion (RSA). In contrast with control women, sera from RSA women induced an enhanced mixed lymphocyte reaction (MLR) against paternal PBMCs, showing increased proliferation and lack of MLR-blocking factor activity. The sera from RSA women inhibited expansion of the FOXP3+ T cell population in TCR-activated PBMCs and showed an imbalance in levels of soluble components of the IL-6 trans-signaling pathway. In comparison with fertile women, those with RSA showed significantly increased levels of soluble IL-6 receptor and IL-6, and decreased levels of soluble gp130, the trans-signaling inhibitor. Finally we found that paternal alloimmunization acts to modulate serum levels of factors involved in the IL-6 trans-signaling pathway and increases the frequency of Treg cells. Consequently, women with reproductive failure show evidence of alteration in the IL-6 trans-signaling pathway which might be associated with abnormal performance of Treg cells in mediating feto-maternal tolerance.

127: Archives of gerontology and geriatrics, 2010 Jul-Aug, 51(1)
Older age and type of surgery predict the early inflammatory response to hip trauma mediated by interleukin-6 (IL-6).

[Abstract]Hip trauma and surgery are associated with systemic inflammatory reaction. However, little evidence exists about the role of IL-6. In order to assess the inflammatory response, we evaluated white blood cell (WBC) count, C-reactive protein (CRP) and IL-6 dynamics in sequential pre- and postsurgical samples collected from 125 elderly patients (mean age 78+/-9 years) undergoing osteosynthesis (OS) for extracapsular hip fractures (n=69), hemiarthroplasty (HA) or urgent total hip arthroplasty for intracapsular fractures (UA) (n=35), and elective total hip arthroplasty for osteoarthrosis (OA) (n=21). Both preoperative CRP and IL-6 levels were higher in patients with intracapsular fractures. IL-6 levels reached peak values immediately after the surgery, while CRP peak levels were reached 48 h after the surgery. The overall inflammatory reaction was more intense in HA patients compared to the other subgroups. Independent of each other, older age and the hip fracture type affected the IL-6 response, while the CRP response depended only on the type of surgery. The abrupt increase in IL-6 immediately after the procedure suggests its involvement in the early stages of the postoperative inflammatory reaction after hip surgery. This reaction is particularly pronounced in elderly patients receiving HA.

128: Veterinary pathology, 2009 Nov, 46(6)
Pro-inflammatory, pleiotropic, and anti-inflammatory TNF-alpha, IL-6, and IL-10 in experimental porcine intervertebral disk degeneration.

[Abstract]The aim of this study was to check the balance between tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-10 (IL-10) in well-developed end-stage disk disease in the disk itself as well as in paradiskal spine. In 6 domestic pigs the cranial bony end plate of the L4 vertebra was perforated to the nucleus pulposus. At 3 months the degenerated experimental and contiguous control disks, together with the adjoining bony and cartilaginous vertebral end plates, bone marrow, and spinal ligaments, were excised and used for immunohistochemical analysis. In general, there were more TNF-alpha and in particular IL-10 positive cells in the degenerated disks than in the control disks, whereas the number of IL-6 labeled cells did not differ among sites or between control and experimental intervertebral disks. These results suggest that TNF-alpha and IL-10 are involved in the late reparatory phases of the experimental disk lesion. Use of an experimental model showed that strictly disk-directed manipulation and degeneration are also reflected in the contiguous vertebrae, including adjoining cartilage, bone, marrow, and ligaments.

129: Brain, behavior, and immunity, 2009 Nov, 23(8)
In-hospital levels of C-reactive protein and IL-6 predict post-operative depressive symptoms among patients undergoing total knee replacement surgery.

[Abstract]Behavioral changes observed following immune system activation are similar to many of the hallmark symptoms of major depressive disorder (MDD), including appetite change, lethargy, fatigue, negative mood and anhedonia. Acute phase proteins, such as interleukin-6 (IL-6) and C-reactive protein (CRP) have been implicated in the production of sickness behavior, and research has revealed significant differences in the levels of these acute phase proteins between depressed and non-depressed individuals. The current study examined whether early post-operative IL-6 and CRP levels predicted subsequent depressive symptoms in 110 patients undergoing total knee replacement surgery (TKR). In-hospital levels of IL-6 and CRP predicted depressive symptoms at three-months following surgery, as indicated by significant main effects and a significant interaction term. Specifically, lower levels of in-hospital CRP and higher levels of IL-6 in-hospital predicted more depressive symptoms three-months following surgery. The finding that levels of acute phase proteins soon after surgery predict subsequent depressive symptoms, if replicated, extends prior research on the relationships between IL-6, CRP, and depression. Further, this predictive relationship suggests the possibility of early identification of individuals at risk for the subsequent development of post-operative depression.

130: Bone marrow transplantation, 2010 Jan, 45(1)
Correlations of HHV-6 viral load and plasma IL-6 concentration with HHV-6 encephalitis in allogeneic stem cell transplant recipients.

[Abstract]This study investigated factors associated with the development of human herpesvirus (HHV)-6 encephalitis. Among 111 enrolled subjects, 12 patients developed central nervous system (CNS) dysfunction. CNS dysfunction in four patients was found to have no association with HHV-6. The remaining eight patients displayed HHV-6 encephalitis (n=3), limbic encephalitis (HHV-6 DNA in cerebrospinal fluid was not examined; n=3) or CNS dysfunction because of an unidentified cause (n=2). Real-time PCR showed CNS dysfunction in the latter eight patients, which developed concomitant with the appearance of high plasma levels of HHV-6 DNA (> or =10(4) copies/ml). Overall, eight of the 24 patients with high-level HHV-6 DNA developed CNS dysfunction, whereas no patients developed CNS dysfunction potentially associated with HHV-6 infection if peak HHV-6 DNA was <10(4) copies/ml. We next analyzed plasma concentrations of IL-6, IL-10 and tumor necrosis factor-alpha among patients who displayed high-level plasma HHV-6 DNA and found elevated IL-6 concentrations preceding HHV-6 infection in patients who developed CNS dysfunction. (Mean+/-s.d.: 865.7+/-1036.3 pg/ml in patients with CNS dysfunction; 56.5+/-192.9 pg/ml in others; P=0.01). These results suggest that high-level HHV-6 load is necessary for the development of HHV-6 encephalitis, and systemic inflammatory conditions before HHV-6 infection form the preparatory conditions for progression to encephalopathy.

131: Pharmacological research : the official journal of the Italian Pharmacological Society, 2009 Dec, 60(6)
Circulating levels of advanced glycation end products (AGE) and interleukin-6 (IL-6) are independent determinants of serum asymmetric dimethylarginine (ADMA) levels in patients with septic shock.

[Abstract]There is a growing body of evidence that nitric oxide (NO) excess plays a central role in the pathogenesis of hypotension and organ failure in patients with septic shock. In addition, recently, asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, has been shown to contribute to the regulation of vascular tone via modulation of NO generation in vivo. However, the kinetics and regulation of serum levels of ADMA in patients with septic shock are largely unknown. Since high mobility group box 1 (HMGB1)-receptor for advanced end products (RAGE) axis is supposed to be involved in the lethality in septic shock, we examined the correlations among serum levels of ADMA, endotoxin, interleukin-6 (IL-6), soluble form of RAGE (sRAGE) and RAGE ligands such as HMGB1 and advanced glycation end products (AGE) in septic shock patients. Fifteen septic shock patients (10 males and 15 females, mean age: 70.1+/-8.5 years) and fifteen age- and sex-matched healthy volunteers were included in this study. The criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference were used for diagnosis of septic shock. All the subjects underwent a complete history and physical examination, determination of blood chemistries, including serum levels of ADMA, endotoxin, IL-6, HMGB1, AGE and sRAGE. Linear and multiple stepwise regression analysis were performed for the determinants of serum levels of ADMA. Serum levels of ADMA were significantly higher than those in healthy volunteers (0.98+/-0.21nmol/mL vs. 0.30+/-0.05nmol/mL, p<0.0001). In univariate analysis, creatinine (p<0.005), endotoxin (p<0.001), IL-6 (p<0.001), HMGB1 (p<0.001), AGE (p<0.001) and sRAGE (p<0.001) were significantly associated with serum ADMA levels. After performing multivariate stepwise regression analyses, IL-6 (p=0.001), AGE (p=0.002) and creatinine (p=0.013) still remained significant independently. The present study is the first demonstration that ADMA levels were significantly elevated in patients with septic shock and that serum IL-6, AGE and creatinine levels were independent determinants of ADMA in these patients. Given the harmful effects of NO excess in septic shock, ADMA levels may be increased as a counter-system against inflammation and oxidative stress in this life-threatening disorder.

132: Clinical calcium, 2009 Mar, 19(3)
[Rheumatoid arthritis in the context of bone and cartilage. IL-6 targeting therapy to retard structural joint damage in patients with rheumatoid arthritis.]

[Abstract]Tocilizumab has been shown to have strong effect to retard the progression of structural joint damage in patients with rheumatoid arthritis. It was approved not only for signs and symptoms but also structural joint damage of rheumatoid arthritis in Japan. In this review, the efficacy, utility, positioning, and the future prospect will be discussed.

133: Bone marrow transplantation, 2009 Feb 23, 34(1)
Association of IL6 and CCL2 gene polymorphisms with the outcome of allogeneic haematopoietic stem cell transplantation.

[Abstract]Various polymorphisms of non-HLA genes have recently been investigated as candidate risk factors in allogeneic haematopoietic SCT (aHSCT). Our study aimed at exploring possible associations of IL6 and CCL2 single nucleotide polymorphisms (SNP) with aHSCT outcome. A total of 166 HLA-identical aHSCT pairs recruited in were genotyped for IL6 -174 G/C, IL6 -597 G/A, CCL2 -2518 A/G and CCL2 -2076 A/T SNPs by PCR with sequence-specific primers (PCR-SSP). The association between IL6 -174 GG genotype and increased risk of acute GVHD was found in whole study group (P=0.03) and in the subgroup of related aHSCT (P=0.01), association between IL6 -597 GG genotype and the occurrence of acute GVHD was detected only in the related aHSCT pairs (P=0.02). Furthermore, reduction in OS was revealed among recipients possessing IL6 -174(*)G allele in the group of related aHSCT pairs (P=0.04). Presence of CCL2 -2076 TT genotype was associated with decrease of OS (P=0.04) and increase of TRM (P=0.02) in patients transplanted by related donor. These results, in the context of previous findings, suggest that IL6 gene polymorphisms may be associated with aHSCT outcome, particularly in patients transplanted from a related donor.Bone Marrow Transplantation advance online publication, 23 February 2009; doi:10.1038/bmt.2009.16.

134: American journal of physiology. Heart and circulatory physiology, 2009 Feb 20, 182(5)
IL-6 Loss Causes Ventricular Dysfunction, Fibrosis, Reduced Capillary Density and Dramatically Alters the Cell Populations of the Developing and Adult Heart.

[Abstract]Interleukin-6 (IL-6) is a pleiotropic cytokine responsible for many different processes including the regulation of cell growth, apoptosis, differentiation and survival in various cell types and organs, including the heart. Recent studies have indicated that IL-6 is a critical component in the cell-cell communication between myocytes and cardiac fibroblasts. In this study, we examine the effects of IL-6-deficiency on the cardiac cell populations, cardiac function and interactions between the cells of the heart, specifically cardiac fibroblasts and myocytes. To examine the effects of IL-6-loss on cardiac function, we used the IL-6(-/-) mouse. IL-6-deficiency caused severe cardiac dilatation, increased accumulation of interstitial collagen and altered expression of the adhesion protein periostin. In addition, flow cytometric analyses demonstrated dramatic alterations in the cardiac cell populations of IL-6(-/- )mice when compared to wild type littermates. We observed a marked increase in the cardiac fibroblast population in IL-6(-/-) mice, while a concommitment decrease was observed in the other cardiac cell populations examined. Moreover, we observed increased cell proliferation and apoptosis in the developing IL-6(-/-) heart. Additionally, we observed a significant decrease in the capillary density of IL-6(-/-) hearts. In order to elucidate the role of IL-6 in the interactions between cardiac fibroblasts and myocytes, we performed in vitro studies and demonstrated that IL-6-deficiency attenuated activation of the STAT3 pathway and VEGF production. Taken together, these data demonstrate that loss of IL-6 causes cardiac dysfunction by shifting the cardiac cell populations, altering the extracellular matrix, and disrupting critical cell-cell interactions. Key words: Interleukin-6, Cardiomyocyte, Fibroblast, Cytokines.

135: Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 2008 Dec, 59 Suppl 6
Frequency of distribution of inflammatory cytokines IL-1, IL-6 and TNF-alpha gene polymorphism in patients with obstructive sleep apnea.

[Abstract]Obesity is one of the most commonly identified factors for the obstructive sleep apnea syndrome (OSAS). Adipose tissue is the source of many cytokines, among them there are IL-6, IL-1, and TNF-alpha. The level of inflammatory cytokines increases in people with OSAS and obesity. The aim of this study was to evaluate the distribution of genotypes in inflammatory cytokine genes in people with obesity-related OSAS. The examined group consisted of 102 person with obesity related-OSAS and 77 normal weight person without OSAS. Genotyping of DNA sequence variation was carried out by restriction enzyme (IL-1: Taq I, IL-6: Lwe I, TNF-alpha: Nco I) analysis of PCR amplified DNA. The study revealed a significant correlation between polymorphism located in the promoter region of inflammatory cytokine genes and obesity-related OSAS.

136: Comparative immunology, microbiology and infectious diseases, 2010 Jan, 33(1)
The impact of staphylococcal mastitis on the level of milk IL-6, lysozyme and nitric oxide.

[Abstract]Mammary gland secretions derived from secretory cows infected with coagulase +ve Staphylococcus spp. was examined for the expression of IL-6, production of lysozyme and NO(x). The examined cows reflected 25 cases of subclinical mastitis and 15 cases of clinically mastitic animals. The IL-6 concentration in the subclinical animals was significantly higher (30.8ng/ml) than the clinically manifested animals (18.0ng/ml) and the normal cows (5.2ng/ml). On the other hand the level of lysozyme although significantly higher than the normal cows (6.9mug/ml) yet its level in the subclinical animals (11.2mug/ml) was lower than that estimated in the clinical animals (15.6mug/ml). Similarly, the level of NO(x) in the normal animals was found to be 5.6muM/ml to increase to 6.2muM/ml in the subclinical mastitic animals and to significantly increase further to 11.5muM/ml in the clinically affected cows. These results suggest the promising use of whey IL-6, lysozyme or/and NO concentration variabilities as prognostic parameters on the degree of the commencement of mastitis in cows.


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