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INTERLEUKIN 1, BETA PROPROTEIN
LATEST LITERATURE
1: Virchows Archiv : an international journal of pathology, 2010 Apr 20,
Influence of IL1B polymorphism on CpG island hypermethylation in Helicobacter pylori-infected gastric cancer.
[Abstract]Helicobacter pylori infection can induce aberrant CpG island hypermethylation in gastric mucosal epithelial cells. Single nucleotide polymorphisms of proinflammatory cytokine genes encoding for interleukin 1B (IL1B), IL6, and IL8 have been demonstrated to be associated with an increased risk of gastric cancer. To identify the influence of host genetic factors in CpG island hypermethylation induced by H. pylori infection, we analyzed H. pylori-infected chronic gastritis (n = 111) and gastric cancer samples (n = 78) for the methylation status of eight genes previously shown to be hypermethylated in chronic gastritis and single nucleotide polymorphisms of IL1B, IL6, and IL8. The methylation levels were then compared between different genotypes. Gastric cancers from patients with the IL1B-511T/T allele showed significantly higher methylation levels in five genes as compared with gastric cancers from IL1B-511 C carriers (P < 0.05). An increased level of hypermethylation in association with the IL1B-511T/T allele was observed in chronic gastritis samples, but the association was not statistically significant. These findings suggest that the IL1B-511T/T allele is associated with enhanced hypermethylation of multiple CpG island loci, which might contribute to an increase in the risk for gastric cancer in individuals with H. pylori infection and IL1B-511T/T allele.
2: International journal of environmental research and public health, 2009 Jul, 6(7)
Epistasis between IL1A, IL1B, TNF, HTR2A, 5-HTTLPR and TPH2 variations does not impact alcohol dependence disorder features.
[Abstract]We assessed a set of biological (HDL, LDL, SGOT, SGPT, GGT, HTc, Hb and T levels) and psychometric variables (investigated through HAM-D, HAM-A, GAS, Liebowitz Social Anxiety Scale, Mark & Mathews Scale, Leyton scale, and Pilowski scale) in a sample of 64 alcohol dependent patients, at baseline and after a detoxification treatment. Moreover, we recruited 47 non-consanguineous relatives who did not suffer alcohol related disorders and underwent the same tests. In both groups we genotyped 11 genetic variations (rs1800587; rs3087258; rs1799724; 5-HTTLPR; rs1386493; rs1386494; rs1487275; rs1843809; rs4570625; rs2129575; rs6313) located in genes whose impact on alcohol related behaviors and disorders has been hypothesized (IL1A, IL1B, TNF, 5-HTTLPR, TPH2 and HTR2A). We analyzed the epistasis of these genetic variations upon the biological and psychological dimensions in the cases and their relatives. Further on, we analyzed the effects of the combined genetic variations on the short - term detoxification treatment efficacy. Finally, being the only not yet investigated variation within this sample, we analyzed the impact of the rs6313 alone on baseline assessment and treatment efficacy. We detected the following results: the couple rs6313 + rs2129575 affected the Leyton -Trait at admission (p = 0.01) (obsessive-compulsive trait), whilst rs1800587 + 5-HTTLPR impacted the Pilowski test at admission (p = 0.01) (hypochondriac symptoms). These results did not survive Bonferroni correction (p < or = 0.004). This lack of association may depend on the incomplete gene coverage or on the small sample size which limited the power of the study. On the other hand, it may reflect a substantial absence of relevance of the genotype variants toward the alcohol related investigated dimensions. Nonetheless, the marginal significance we detected could witness an informative correlation worth investigating in larger samples.
3: Carcinogenesis, 2009 Jul, 30(7)
A specific interleukin-1B haplotype correlates with high levels of IL1B mRNA in the lung and increased risk of non-small cell lung cancer.
[Abstract]Epidemiological evidence suggests a relationship between chronic inflammation and lung cancer. Inflammation in the lung may be modulated by host genetic factors such as polymorphisms in inflammatory genes. Identification of polymorphisms in inflammatory genes may help understanding interindividual differences in susceptibility to lung cancer. We have investigated single-nucleotide polymorphisms (SNPs) and their haplotypes in the regulatory region of the IL1B gene in association to non-small cell lung cancer (NSCLC) risk. Our previous work showed that two promoter SNPs C-511T and T-31C modulated NSCLC risk. In the present study, we show that G-3893A and G-1464C located in the enhancer region of the IL1B gene may also affect this risk, with odds for developing NSCLC being 0.69 [95% confidence interval (CI), 0.52-0.92] for -3893 A-allele and 0.63 (95% CI, 0.47 - 0.83) for -1464 C-allele. The associations were particularly prominent in patients with TP53 mutations in the tumor. Inference of the haplotype structures showed that -3893 G, -1464 G, -511 C and -31 T formed a specific haplotype (GGCT) with near complete linkage disequilibrium in lung cancer patients but not in controls. Furthermore, the risk haplotype (GGCT) was present in 65% of cases compared with 36% of controls. Quantitative analysis of RNA in normal lung tissue of the patients showed that the risk haplotype was correlated with significantly higher IL1B messenger RNA (mRNA) levels compared with the non-risk haplotype (ACTC). These data suggest that a specific IL1B haplotype associated with increased IL1B gene expression increases the risk of NSCLC.
4: Gene expression patterns : GEP, 2009 Jun, 9(5)
Effect of fluid flow-induced shear stress on human mesenchymal stem cells: differential gene expression of IL1B and MAP3K8 in MAPK signaling.
[Abstract]Human bone marrow-derived mesenchymal stem cells (MSCs) can differentiate into numerous cell lineages, making them ideal for tissue engineering. Mechanical forces and mechanotransduction are important factors influencing cell responses, although such data are limited for MSCs. We investigated the effect of different profiles of fluid flow-induced shear stress on mitogen-activated protein kinase (MAPK) signaling pathway gene expression in MSCs using DNA microarray and quantitative real-time reverse transcription-PCR analysis. In response to different magnitudes and durations of fluid flow-induced shear stress, we observed significant differential gene expression for various genes in the MAPK signaling pathway. Independent of magnitude and duration, shear stress induced consistent and marked up-regulation of MAP kinase kinase kinase 8 (MAP3K8) and interleukin-1 beta (IL1B) [2-fold to >35-fold, and 4-fold to >50-fold, respectively]. We also observed consistent up-regulation of dual specificity phosphatase 5 and 6, growth arrest and DNA-damage-inducible alpha and beta, nuclear factor kappa-B subunit 1, Jun oncogene, fibroblast growth factor 1, and platelet-derived growth factor alpha. Our data support MAP3K8-induced activation of different MAPK signaling pathways in response to different profiles of shear stress, possibly as a consequence of shear-induced IL1B expression. Thus, MAP3K8 may be an important mediator of intracellular mechanotransduction in human MSCs.
5: Clinical oral implants research, 2009 Feb, 20(2)
Analysis of the association of IL1B (C+3954T) and IL1RN (intron 2) polymorphisms with dental implant loss in a Brazilian population.
[Abstract]BACKGROUND: Although dental implants have a high success rate, failures occur, in spite of adequate clinical conditions. Together with the observation that multiple implant losses occur in certain groups of individuals (clusterization phenomenon), this suggests that host response may influence implant failure. Little is known about the influence of genetic susceptibility on implant loss. Interleukin (IL)-1 beta and IL-1 ra are believed to play a key role in the immune-inflammatory response, and polymorphisms IL1B (C+3954T) and IL1RN (intron 2) are shown to alter the coding proteins expression. OBJECTIVES: The aim of this study was to investigate the association between dental implant loss and polymorphisms IL1B (+3954) and IL1RN (intron 2). MATERIAL AND METHODS: The study population (n=266) was divided into Test group (T)- 90 subjects with implant loss, and Control group (C)- 176 subjects without any implant failure. Genotyping was performed by PCR-RFLP. RESULTS: The number of present teeth was observed to influence implant loss. No differences in genotype and allele frequencies between C and T were found for IL1B (+3954) and IL1RN (intron 2) polymorphisms. However, the analysis of the whole study population (control and test groups) showed that genotype 2/2 was significantly more frequent in individuals with multiple implant losses (n=35) than in individuals that lost up to a single implant (n=231) (OR: 3.07, IC: 1.13-8.34, P=0.027). CONCLUSION: It was observed that number of teeth and edentulism were associated with implant loss. Genotype 2/2 of IL1RN polymorphism was significantly more frequent in patients who presented multiple losses, which suggests that the clusterization phenomenon has a genetic basis.
6: The international journal of biochemistry & cell biology, 2009 Jan 8, 20(2)
IL1B promoter polymorphism regulates the expression of gastric acid stimulating hormone gastrin.
[Abstract]It is important to dissect the effect of the alternative alleles of a functional SNP on the entire biochemical pathway for the complete understanding of the mechanism of the manifestation of complex diseases. IL1B-511C>T and -31C>T promoter polymorphisms have been suggested as potential susceptibility loci for Helicobacter pylori associated gastroduodenal diseases. We report that altered expression of IL1B due to a specific polymorphism in its promoter modulates the expression of gastrin, an acid regulating hormone. Treatment of gastric carcinoma cells, AGS, with IL1B resulted in a 20-fold reduction in gastrin expression. Gastrin promoter assay showed that IL1B inhibits gastrin expression at the transcriptional level and part of this inhibitory process is mediated via activation of NFkappaB and involvement of HDACs. An almost 3-fold increase in IL1B expression was observed when AGS cells were transfected with -31TIL1B expression plasmid in comparison to -31CIL1B. The -31TIL1B induced a 2-fold greater repression of the gastrin luciferase activity compared to -31CIL1B. This signaling of the -31TIL1B variant allele driven IL1B revealed an almost 1.5-fold greater expression of NFkappaB. Thus, this study showed that a single base substitution at the -31 position of the IL1B promoter brought about differential expression of IL1B which differentially altered both NFkappaB activation and gastrin expression.
7: Molecular vision, 2008, 14(2)
Association of -31T>C and -511 C>T polymorphisms in the interleukin 1 beta (IL1B) promoter in Korean keratoconus patients.
[Abstract]PURPOSE: To investigate the genetic association between unrelated Korean keratoconus patients and interleukin 1 alpha (IL1A), interleukin 1 beta (IL1B), and IL1 receptor antagonist (IL1RN) gene polymorphisms. METHODS: We investigated the association between IL1A (rs1800587, rs2071376, and rs17561), IL1B (rs1143627, rs16944, rs1143634, and rs1143633), and IL1RN (rs419598, rs423904, rs424078, and rs315952, variable number tandem repeat [VNTR]) polymorphisms in 100 unrelated Korean keratoconus patients. One hundred control individuals without any corneal disease were selected from the general population. Polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) analysis and direct sequencing were used to screen for genetic variations in the IL1 gene cluster. Haplotypes for the IL1 gene cluster were constructed using Haploview version 4.0. RESULTS: We analyzed a total of 12 polymorphic sites in the IL1 gene cluster. Among them, the -511 (rs16944) and -31 (rs1143627) positions in the promoter region of IL1B were significantly different between patient and control groups. The C allele of rs16944 (-511C>T, p=0.022, odds ratio of risk [OR]=1.46, 95% confidence intervals [CI] 0.94<2.27) and the T allele of rs1143627 (-31T>C, p=0.025, OR=1.43, 95% CI 0.92<2.22) were associated with a significantly increased risk of keratoconus in Korean patients. Linkage of the two alleles, -31*C and -511*T, was associated with an increased risk for keratoconus with OR=2.38 (p=0.012, 95% CI=1.116-5.046). The *C/*A genotype of rs2071376 in IL1A intron 6 was significantly different between the keratoconus patients and control subjects (p=0.034, OR=0.59, 95% CI 0.32<1.11). Other polymorphisms did not show an association with keratoconus risk. CONCLUSIONS: This is the first report of IL1 gene cluster mutation screening in Korean keratoconus patients. Significant differences in allelic frequency of IL1B between keratoconus patients and the control group suggest that IL1B polymorphisms may play a role in the susceptibility of unrelated Koreans to develop keratoconus.
8: American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics, 2008 Nov 14, 14(2)
Tagging SNP association study of the IL-1beta gene (IL1B) and childhood-onset mood disorders.
[Abstract]Given substantial evidence for IL-1beta involvement in the etiology of depression, the IL1B gene is a strong candidate for involvement in susceptibility to depressive disorders. However, association studies investigating this, to date, have been limited to just two polymorphisms (rs1143627[-31T/C] and rs16944[-511C/T]) that constitute only a fraction of the genetic variation that is actually present across this gene in the population. Here, in a family-based association study of childhood-onset mood disorders (COMD), characterized by onset of depression before the age of 15, we have used a gene-wide approach, employing a panel of five tagging SNPs spanning the entire gene. Based on TDT analyses of both individual alleles and haplotypes, in a study sample of 646 families (with 782 affected children), none of the SNPs, including those implicated in transcriptional regulation of the gene, showed evidence for association with COMD. This is the largest and most comprehensive study of IL1B in relation to mood disorders that has been carried out, to date. The results do not support the involvement of IL1B as a major factor in genetic risk for early-onset mood disorders. (c) 2008 Wiley-Liss, Inc.
9: Mutation research, 2008 Oct 30, 656(1-2)
Allele-specific induction of IL1B -31T/C promoter polymorphism by lung carcinogens.
[Abstract]Environmental and occupational toxicants may induce pulmonary inflammation. Chronic inflammation has been linked to several human diseases and also to initiation and promotion of cancer. Generation of reactive oxygen/nitrogen species (ROS/RNS), secretion of cytokines, chemokines and pro-angiogenic factors are believed to play a role. Interleukin IL-1beta, encoded by the IL1B gene, is a key cytokine produced and secreted by many cell types after activation by biological or chemical agents. Several polymorphisms in the IL1B gene have been identified, and some are associated with increased risk for lung cancer. Especially, the IL1B -31T/C polymorphism has received attention. We have investigated the effect of the lung carcinogens cigarette-smoke condensate (CSC) and benzo[a]pyrene (B[a]P) on the promoters of the IL1B gene varying only at the site of the -31T/C polymorphism. The promoter fragments containing either C or T were cloned in luciferase reporter vectors and transfected into human lung epithelial NCI-H2009 cells. The results show that treatment of the transfected cells with CSC or B[a]P induced the promoter significantly above the control level. Interestingly, the promoter with the wild-type allele T in position -31 showed the stronger induction when compared with the promoter with variant allele C in this position. Bioinformatics and DNA-protein analysis indicated the presence of a novel transcription-factor binding site and the formation of protein complexes at the C promoter.
10: Atherosclerosis, 2009 Feb, 202(2)
IL1B genetic variation and plasma C-reactive protein level among young adults: the CARDIA study.
[Abstract]OBJECTIVE: Interleukin-1B (IL1B) modulates C-reactive protein (CRP) expression. However, whether IL1B genetic variation is associated with CRP level is unknown. Further, obesity, a state of low-grade inflammation that influences cellular IL-1 functions may modify this association. METHODS AND RESULTS: Study participants (N=3289), 48% blacks and 52% whites, had CRP level measurements at year 7 and year 15 examinations as part of the CARDIA study. Ten tag single nucleotide polymorphisms (SNPs) that characterize common IL1B gene variation were genotyped. In SNP analysis, no significant associations with either level or change in time CRP were observed after multiple testing adjustments. However, global ILIB gene variation was associated with year 7 to year 15 change in CRP (global nominal p=0.004, multiple testing corrected p=0.048) among obese blacks. Compared to the commonest haplotype, a common haplotype that includes the SNP rs1143642 was associated with greater increases in CRP from year 7 to year 15 among obese blacks and whites while another common haplotype that includes the SNP rs3917356 was associated with decreased change in CRP from year 7 to year 15 among obese blacks. The rare alleles of ILIB SNPs, SNP 7114 (rs1143642) and SNP 3298 (rs3917356), were associated with greater increases and decreases in CRP from year 7 to year 15 among blacks, respectively, compared to their common variants. CONCLUSION: IL1B genetic variation may have a role in CRP level regulation and this association may be modified by obesity.
11: Human genetics, 2008 May, 123(4)
IL1B gene promoter haplotype pairs predict clinical levels of interleukin-1beta and C-reactive protein.
[Abstract]Interleukin-1beta (IL-1beta) activates inflammatory mediator cascades and has been implicated in the pathogenesis of several diseases. Single nucleotide polymorphisms (SNPs) of the IL1B promoter have been associated with various inflammatory diseases. We recently reported that IL1B gene transcription was influenced by four promoter SNPs, and that individual SNP function in vitro was governed by haplotype context. In the present study we tested the in vivo relevance of this observation by comparing IL1B promoter haplotype-pairs with IL-1beta protein levels in 900 gingival tissue fluid samples. Three SNPs (-511, -1464, -3737) defined four IL1B promoter haplotypes that occurred in the study population and could be assigned unambiguously to each chromosome. The four haplotypes defined ten haplotype-pairs of which four pairs, representing 57% of the population, were associated with 28-52% higher IL-1beta protein levels in vivo. Two of these pairs, characterized by homozygosity for the common allele at -3737, were also associated with raised serum levels of C-reactive protein (p = 0.02). We validated these findings in stimulated peripheral blood mononuclear cells (PBMCs) from a separate population (N = 70). PBMCs with IL1B haplotype-pairs associated with higher in vivo levels of IL-1beta produced 86-287% more IL-1beta in vitro than the reference group. We believe that this is the first demonstration of a relationship between in vivo levels of an inflammatory mediator and gene promoter haplotypes on both chromosomes. These findings may apply to other inducible genes and could provide a logical framework for exploring disease risk related to genetic variability in pathogenic mediators.
12: Hematological oncology, 2008 Jun, 26(2)
Interleukin-1B (IL1B) and interleukin-6 (IL6) gene polymorphisms are associated with risk of chronic lymphocytic leukaemia.
[Abstract]Common polymorphisms in genes encoding for cytokines implicated in the inflammatory response and Th1/Th2 balance might play a role in the development and prognosis of chronic lymphocytic leukaemia (CLL). To test the hypothesis, we investigated 13 single nucleotide polymorphisms (SNPs) in nine of such genes in a population-based case-control study, conducted in the Italian region of Sardinia in 1999-2003. Forty incident CLL cases and 113 population controls were available for study. The following SNPs were selected: IL1A-889C > T, IL1RN 9589A > T, IL1B-31C > T, IL1B-511C > T, IL2-384T > G, IL6-174G > C, IL6-597G > A, IL10-1082A > G, IL10-3575T > A, TNF-308G > A, LTA- 91A > C, LTA 252A > G and CARD15 nt1007. After adjusting by age and gender, individuals homozygous for the IL1B-511T allele run a lower risk of CLL (OR = 0.1, 95% CI 0.0, 0.8, p = 0.032), while risk showed a 4.5-fold increase associated with the genotype homozygous for the IL6-174C allele (OR = 4.5; 95% CI 1.1, 19.3, p = 0.041). Individuals homozygous for the IL6-174C allele and carrying the homozygous IL1B-511C allele showed an 11-fold increase in CLL risk (OR = 11.4, 95% CI 1.9, 69.4, p = 0.008). None of the other interleukin SNPs evaluated showed any association with CLL risk. Large multicentre pooled studies are warranted, achieving the statistical power required to confirm whether IL6 and IL1B gene polymorphisms might play a role in CLL development and prognosis, as well as the null associations herein reported.
13: Obesity (Silver Spring, Md.), 2008 Mar, 16(3)
IL6 and IL1B polymorphisms are associated with fat mass in older men: the MrOS Study Sweden.
[Abstract]There is growing evidence that immune functions are linked to the regulation of body fat. Our studies of knockout mice indicate that both endogenous interleukin (IL)-6 and IL-1 can suppress mature-onset obesity. We now investigated whether four common polymorphisms of the IL6 and IL1 systems are associated with the fat mass measured with dual-energy X-ray absorptiometry (DXA) in elderly men (n = 3,014). The study subjects were from the Swedish part of the MrOS multicenter population study and 69-81 years of age. The IL6 -174 G>C (Minor allele frequency (MAF) = 48%) gene promoter polymorphism was associated with the primary outcome total fat mass (P = 0.006) and regional fat masses, but not with lean body mass. The IL1B -31T>C (MAF = 34%) polymorphism was also associated with total fat (P = 0.007) and regional fat masses, but not lean body mass. The IL-1 receptor antagonist (IL-1ra) gene (IL1RN) +2018 T>C (MAF = 27%) polymorphism (in linkage disequilibrium (LD) with a well-studied variable number tandem repeat of 86 base pair (bp)) and IL1B +3953 C>T (MAF = 26%) polymorphism were not associated with total fat mass. In conclusion, the IL-1 and IL-6 systems, shown to suppress mature-onset obesity in experimental animals, contain gene polymorphisms that are associated with fat, but not lean, mass in elderly men.
14: European journal of haematology, 2008 Jan, 80(1)
Intracellular HMGB1 transactivates the human IL1B gene promoter through association with an Ets transcription factor PU.1.
[Abstract]High mobility group box 1 protein (HMGB1), originally described as a non-histone, DNA binding protein, was recently identified as a late mediator of inflammation via its extracellular release from activated macrophages/monocytes. In the present study, we report that intracellular HMGB1 synergizes with a macrophage/monocyte-specific E26 transformation-specific sequence (Ets) transcription factor PU.1 to transactivate the promoter of the IL1B gene coding a 31-kDa proIL-1beta protein. The -131 to +12 IL1B promoter, which possesses a PU.1 binding motif essential for its transactivation, was induced when HMGB1 expression vector was transfected into murine RAW264.7 macrophage cells. Our glutathione S-transferase-pulldown and coimmunoprecipitation assays demonstrated direct physical interaction of HMGB1 with PU.1. Deletion of the PU.1 winged helix-turn-helix DNA-binding domain inhibited the association of the two proteins. In electrophoretic mobility shift assay using recombinant PU.1 protein, a ternary complex of PU.1, HMGB1 and PU.1-binding element within the IL1B promoter was generated. The importance of PU.1 was further supported by our observation that induction of the IL1B promoter was obtained only after PU.1 expression in PU.1-deficient murine EL4 thymoma cells. Thus, our data raise the possibility of a novel mechanism which sustains and amplifies inflammatory reactions through physical interaction of PU.1 with intracellular HMGB1 in macrophages/monocytes.
15: International endodontic journal, 2007 Jul, 40(7)
Association of CD14, IL1B, IL6, IL10 and TNFA functional gene polymorphisms with symptomatic dental abscesses.
[Abstract]AIM: To investigate in individuals with symptomatic dental abscesses the occurrence of functional polymorphisms within five genes involved with the immune response. The functional gene polymorphisms analysed were CD14 (-260 C/T), IL1B (+3954 C/T), IL6 (-174 G/C,), IL10 (-1082 G/A) and TNFA (-308 G/A). METHODOLOGY: Genomic DNA obtained from oral swabs from individuals with symptomatic dental abscesses and asymptomatic inflammatory periapical lesions, without previous exacerbation, was submitted to restriction fragment length polymorphism (RFLP) analyses to determine each individual genotype. The chi-square and principal components analysis tests were used for statistical analysis. RESULTS: A significant association was observed between the occurrence of the GG genotype or the G allele expression of the polymorphic locus-174 (G/C) of the IL6 gene, and the presence of the symptomatic dental abscesses in women and in individuals < or =35 years old. The principal components analysis suggested predominance of the symptomatic dental abscesses in individuals displaying: high-producer IL6 genotype; intermediate and high-producer IL1B genotypes and low-producer TNFA genotype. CONCLUSIONS: The present study suggests that genetic factors are associated with susceptibility to develop symptomatic dental abscesses.
16: Arteriosclerosis, thrombosis, and vascular biology, 2007 Jun, 27(6)
Haplotypes of IL1B, IL1RN, IL1R1, and IL1R2 and the risk of venous thrombosis.
[Abstract]OBJECTIVE: It has been suggested that the overall effect of the major proinflammatory cytokine interleukin-1 (IL-1) on coagulation and fibrinolysis is prothrombotic. The aim of this study was to investigate whether common variations in IL1B, IL1RN, IL1R1, and IL1R2 influence the risk of venous thrombosis. METHODS AND RESULTS: In a case-control study on the causes of deep venous thrombosis, the Leiden Thrombophilia Study (LETS), we genotyped 18 single nucleotide polymorphisms (SNPs) in IL1B, IL1RN, IL1R1, and IL1R2, enabling us to tag a total of 25 haplotype groups. Overall testing of the haplotype frequency distribution in patients and controls indicated that a recessive effect was present in IL1RN (P=0.031). Subsequently the risk of venous thrombosis was calculated for each haplotype of IL1RN. Increased thrombotic risk was found for homozygous carriers of haplotype 5 (H5, tagged by SNP 13888T/G, rs2232354) of IL1RN (Odds ratio=3.9; 95% confidence interval: 1.6 to 9.7; P=0.002). No risk was associated with haplotype 3 of IL1RN, which contains the frequently examined allele 2 variant of the intron 2 VNTR. CONCLUSIONS: We found that IL1RN-H5H5 carriership increases the risk of venous thrombosis.
17: Molecular immunology, 2007 Jul, 44(13)
Phosphorylation of IRF8 in a pre-associated complex with Spi-1/PU.1 and non-phosphorylated Stat1 is critical for LPS induction of the IL1B gene.
[Abstract]Rapid induction of transcription is known to be mediated by factors which bind DNA following post-translational modification. We report here that non-tyrosine phosphorylated (NTP)-Stat1 is involved in a cooperative interaction with Spi-1/PU.1 and IRF8 to form a pre-associated, poised complex for IL1B gene induction. A double point mutation at a putative STAT binding site, which overlaps this composite Spi-1 x IRF8 site located in the LPS and IL-1 response element (LILRE), inhibited human IL1B LPS-dependent reporter activity to about 10 percent of the control wild type vector. Chromatin immunoprecipitation revealed stimulation-independent constitutive binding of IRF8, Spi-1 and NTP-Stat1 at the LILRE, while binding of C/EBP beta was activated at an adjacent C/EBP beta site after LPS stimulation. In contrast to Stat1, IRF8 was tyrosine phosphorylated following LPS treatment. Supporting the involvement of NTP-Stat1, LPS-induced IL1B reporter activity in monocytes was enhanced by ectopic expression of NTP-Stat1 Y701F. In contrast, co-expression of a Y211F IRF8 mutein functioned as a dominant-negative inhibitor of LPS-induced IL1B reporter activity. In vitro DNA binding using extracts from LPS-treated monocytes confirmed that the LILRE enhancer constitutively binds a trimolecular complex containing IRF8, Spi-1 and NTP-Stat1. Binding studies using in vitro-expressed proteins revealed that NTP-Stat1 enhanced the binding of Spi-1 and IRF8 to the LILRE. Co-expression of TRAF6, an LPS surrogate, with Spi-1 and IRF8 enhanced IL1B reporter activity in HEK293R cells, which was dramatically reduced when Y211F IRF8 was co-expressed. These results suggest that the rapid transcriptional induction of an important inflammatory gene is dependent upon constitutive cooperative binding of a Spi-1 x IRF8 x NTP-Stat1 complex to the LILRE, which primes the gene for immediate induction following IRF8 phosphorylation. Phosphorylation of chromatin pre-associated factors like IRF8 may be an important strategy for the rapid transcriptional activation of genes involved in innate immunity.