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IL-6 Gene (il-6 + gene)
Selected AbstractsSuppression of experimental colitis in mice by CD11c+ dendritic cellsINFLAMMATORY BOWEL DISEASES, Issue 2 2009Joseph E. Qualls PhD Abstract Background: The innate immune system serves a critical role in homeostasis of the gastrointestinal (GI) tract. Both macrophages (MØs) and dendritic cells (DCs) have been shown to have pathogenic roles in animal models of inflammatory bowel disease. However, studies by several labs have established that resident MØs and DCs within the normal GI tract maintain an immunosuppressive phenotype compared to that seen in other peripheral sites. Recent studies by our lab demonstrated that the depletion of both MØs and DCs before the initiation of dextran sodium sulfate (DSS)-induced colitis resulted in exacerbation of disease, partly caused by increased neutrophil influx. Methods/Results: In this current report, DSS-induced colitis was shown to be significantly more severe when DCs were selectively depleted in mice as indicated by changes in weight loss, stool consistency, rectal bleeding, and histopathology. In contrast to enhanced colitis in MØ/DC-depleted mice, which was associated with increased neutrophil influx, increased colitis in DC-depleted mice was not associated with an increase in neutrophils in the colon, as shown by CXCL1 chemokine levels and myeloperoxidase (MPO) activity. However, increased IL-6 gene and protein expression in colon tissues correlated positively with increased colitis severity in DC-depleted mice compared to colitis in DC-intact mice. Conclusions: This study demonstrates that resident DCs can suppress the severity of acute DSS colitis and that regulation of IL-6 production may contribute to DC-mediated control of intestinal inflammation. (Inflamm Bowel Dis 2008) [source] Interleukin-6 gene polymorphism is an age-dependent risk factor for myocardial infarction in menINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 6 2005M. Chiappelli Summary Several studies show that inflammatory components may contribute to atherosclerosis and increase the risk for myocardial infarction (MI). Interleukin-6 (IL-6) is a key pro-inflammatory and immune-modulatory cytokine of relevance for cardiovascular diseases. In this case-control study, 200 patients with MI and 257 healthy controls were genotyped for the polymorphism present in ,174 promoter region of the IL-6 gene. Plasma concentrations of IL-6 and C-reactive protein (CRP) in a group of patients and controls were measured. The ,174 C allele was associated with an increased risk of developing MI (OR = 2.886, c.i. = 1.801,4.624, P = 0.0001) in older patients, while no association was found in younger ones. The IL-6 plasma levels were higher in patients with MI carrying the CC genotype than in GG patients (CC carriers, IL-6 = 2.97 pg mL,1 vs. GG carriers = 1.81 pg mL,1, P = 0.016). A positive correlation of IL-6 levels with those of CRP in serum from patients with MI was also found. Data from this study suggest that the C allele of the promoter polymorphism in the IL-6 gene is a risk factor for MI in the elderly, and the production of the IL-6 is differentially affected by different genotypes of the IL-6 ,174 promoter polymorphism. [source] Interleukin-6 Gene Polymorphism Is Related to Bone Mineral Density During and After Puberty in Healthy White Males: A Cross-Sectional and Longitudinal StudyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2000Mattias Lorentzon Abstract Bone mineral density (BMD) is under strong genetic control and is the major determinant of fracture risk. The cytokine interleukin-6 (IL-6) is an important regulator of bone metabolism and is involved in mediating the effects of androgens and estrogens on bone. Recently, a G/C polymorphism in position ,174 of the IL-6 gene promoter was found. We investigated this genetic polymorphism in relation to BMD during late puberty and to peak bone mass, in healthy white males. We identified the IL-6 genotypes (GG, GC, and CC) in 90 boys, age 16.9 ± 0.3 years (mean ± SD), using polymerase chain reaction (PCR). BMD (g/cm2) at the femoral neck, lumbar spine, and total body was measured using dual energy X-ray absorptiometry. The volumetric BMD (vBMD; mg/cm3) of the lumbar spine was estimated. Differences in BMD in relation to the genotypes were calculated using analysis of variance (ANOVA). Subjects with the CC genotype had 7.9% higher BMD of the femoral neck (p = 0.03), 7.0% higher BMD of the lumbar spine (p < 0.05), and 7.6% higher vBMD of the lumbar spine (p = 0.04), compared with their GG counterparts. Using multiple regression, the IL-6 genotypes were independently related to total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p < 0.05), neck BMD (CC > GG; p = 0.01), spine BMD (CC > GG; p = 0.01), and spine vBMD (CC > GG; p = 0.008). At age 19.3 ± 0.7 years (mean ± SD; 88 men) the IL-6 genotypes were still independent predictors for total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p = 0.03), spine BMD (CC > GG; p = 0.02), and spine vBMD (CC > GG; p = 0.003), while the IL-6 genotypes were not related to the increase in bone density seen after 2 years. We have shown that polymorphism of the IL-6 gene is an independent predictor of BMD during late puberty and of peak bone mass in healthy white men. [source] Association between interleukin-6 promoter haplotypes and aggressive periodontitisJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2008Luigi Nibali Abstract Background: Interleukin-6 (IL-6) polymorphisms have been shown to affect IL-6 promoter activity. This study investigated the possible role of IL-6 genetic polymorphisms and haplotypes in the predisposition to aggressive periodontitis (AgP). Material and Methods: A case,control association study on 224 AgP patients and 231 healthy controls was performed in order to detect differences in genotype distributions of five single nucleotide polymorphisms (SNPs) located in the promoter region of the IL-6 gene. Results: The IL-6 ,1363 polymorphism was associated with a diagnosis of AgP in subjects of all ethnicities (p=0.006, adjusted logistic regression). The ,1480 SNP was associated with LAgP in subjects of all ethnicities (p=0.003). The ,1480 and ,6106 polymorphisms were associated with Localized AgP in Caucasians (n=24) (p=0.007 and 0.010, respectively). Haplotypes determined by the ,1363 and ,1480 polymorphisms were also associated with LAgP (p=0.001) in Caucasians. Conclusions: This study supports the hypothesis of a link between IL-6 genetic factors and AgP and highlights the importance of two IL-6 polymorphisms (,1363 and ,1480) in modulating disease phenotype and susceptibility. [source] Interleukin-6 genotype and risk for cerebral palsy in term and near-term infants,ANNALS OF NEUROLOGY, Issue 5 2009Yvonne W. Wu MD Objective Chorioamnionitis is associated with increased risk for cerebral palsy (CP) in term infants. A functional polymorphism in the interleukin-6 (IL-6) gene has been implicated in newborn brain injury. We studied whether the IL-6 -174 G/C polymorphism confers increased risk for CP in term infants. Methods This population-based case,control study included 334,333 live-born infants born at ,36 weeks gestation within Kaiser Permanente Medical Care Program from 1991 to 2002. Case patients (n = 250) were identified from electronic records and confirmed by chart review, and comprised all infants with spastic or dyskinetic CP not caused by developmental abnormalities who had a neonatal blood specimen available for study. Control patients (n = 305) were randomly selected from the study population. Results Compared with genotype GG, the less common CC genotype was associated with increased risk for overall CP (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.5,4.6), quadriparetic CP (OR, 4.1; 95% CI, 1.8,9.3), and hemiparetic CP (OR, 2.7; 95% CI, 1.3,5.7), after controlling for race. The C allele conferred increased risk for CP in both recessive and additive genetic models. In multivariate analysis controlling for race, independent risk factors for CP included CC genotype compared with GG (OR, 2.4; 95% CI, 1.3,4.4), clinical chorioamnionitis (OR, 4.6; 95% CI, 2.1,10.4), maternal age , 35 (OR, 2.6; 95% CI, 1.6,4.1), and male sex (OR, 1.6; 95% CI, 1.1,2.4). Interpretation Our data suggest that a functional polymorphism in the IL-6 gene is a risk factor for CP among term and near-term infants. Ann Neurol 2009;66:663,670 [source] Enhancement of immunity and resistance in mice by pig IL-6 gene and CpG motifs encapsulated in chitosan nanoparticleBIOTECHNOLOGY JOURNAL, Issue 2 2008Qian Chen Abstract This study was conducted to explore the synergetic effect of a novel plasmid containing a porcine IL-6 gene and CpG motifs on immunity of mice in order to develop an effective adjuvant to boost resistance against infection. The synthetic oligodeoxynucleotide containing 11 CpG motifs was inserted into the reconstructed VR1020 plasmid containing the pig IL-6 gene (VRPIL6), designated VRIL6C, and then encapsulated in chitosan nanoparticles (CNP) prepared by ionic cross linkage, designated VRIL6C-CNP. The 3-week old mice were injected, respectively, with VRIL6C-CNP, VRIL6-CNP, CpG-CNP and VR1020-CNP to detect the changes of immunity. At 28 days post inoculation, the mice were challenged with virulent hemolytic serotype 2 Streptococcus to test their resistance against infection. The results showed that there was a significant increase in immunoglobulins and interleukins in mice receiving VRIL6C-CNP compared with the control groups, as well as an increase in the lymphocytes and monocytes in the inoculated mice, so that the immunity was remarkably improved in the VRIL6C-CNP group. The challenge provoked stronger immunity and protection against infection in the VRIL6C-CNP group than in the control mice that manifested severe symptoms and lesions. This suggests that VRIL6C-CNP could remarkably enhance the nonspecific immunity of mice, and facilitate the development of an effective immunopotentiator to promote the resistance of the animals against infection. [source] Effects of Alcohol Consumption on Iron Metabolism in Mice with Hemochromatosis MutationsALCOHOLISM, Issue 1 2007Jonathan M. Flanagan Background: Alcoholic liver disease is associated with increased hepatic iron accumulation. The liver-derived peptide hepcidin is the central regulator of iron homeostasis and recent animal studies have demonstrated that exposure to alcohol reduces hepcidin expression. This down-regulation of hepcidin in vivo implies that disturbed iron sensing may contribute to the hepatosiderosis seen in alcoholic liver disease. Alcohol intake is also a major factor in expression of the hemochromatosis phenotype in patients homozygous for the C282Y mutation of the HFE gene. Methods: To assess the effect of alcohol in mice with iron overload, alcohol was administered to mice with disrupted Hfe and IL-6 genes and Tfr2 mutant mice and their respective 129x1/SvJ, C57BL/6J, and AKR/J wild-type congenic strains. Iron absorption, serum iron levels, and hepcidin expression levels were then measured in these mice compared with water-treated control mice. Results: Alcohol was shown to have a strain-specific effect in 129x1/SvJ mice, with treated 129x1/SvJ mice showing a significant increase in iron absorption, serum iron levels, and a corresponding decrease in hepcidin expression. C57BL/6J and AKR/J strain mice showed no effect from alcohol treatment. 129x1/SvJ mice heterozygous or homozygous for the Hfe knockout had a diminished response to alcohol. All 3 strains were shown to have high blood alcohol levels. Conclusions: The effect of alcohol on iron homeostasis is dependent on the genetic background in mice. In an alcohol-susceptible strain, mutation of the Hfe gene diminished the response of the measured iron indices to alcohol treatment. This indicates that either maximal suppression of hepcidin levels had already occurred as a result of the Hfe mutation or that Hfe was a component of the pathway utilized by EtOH in suppressing hepcidin production and increasing iron absorption. [source] Statins enhance toll-like receptor 4-mediated cytokine gene expression in astrocytes: Implication of Rho proteins in negative feedback regulationJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2008Gregory W. Konat Abstract Toll-like receptors (TLRs) are sentinels of innate immunity that recognize pathogenic molecules and trigger inflammatory response. Because inflammatory mediators are detrimental to the host, the TLR response is regulated by feedback inhibition. Statins, the inhibitors of isoprenoid biosynthesis, have been shown to be potent modulators of TLR activity, and this modulation may provide insight regarding mechanisms of the feedback inhibition. In the present study, we examined feedback mechanisms that regulate TLR4 activity in astrocytes using statins to perturb postligational signaling. Astrocytic cultures established from newborn rat brains were exposed to lipopolysaccharide (LPS), the ligand for TLR4. The up-regulation of expression of genes encoding interleukin (IL)-1,, IL-6, and tumor necrosis factor-, (TNF,) was determined by real-time RT-PCR. Pretreatment of the cells with either atorvastatin or simvastatin enhanced the LPS-induced up-regulation of cytokine gene expression. The most profound enhancement of approximately 17-fold was observed for the Il-6 gene. The enhancements for the Tnfa and Il-1b genes were approximately 5- and 3.5-fold, respectively. Mevalonate fully reversed the effects of statins, indicating that these drugs act through the inhibition of isoprenoid synthesis. The inhibition of protein geranylgeranylation, but not protein farnesylation, mimicked the effects of statins, strongly indicating that the enhancement is mediated by the Rho proteins. In support of this notion, pretreatment of cells with toxin B, a specific inhibitor of the Rho proteins, also enhanced LPS-triggered up-regulation of the cytokine genes. These results indicate that the Rho proteins are involved in the activation of negative feedback inhibition of TLR4 signaling in astrocytes. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||