Tumor necrosis factor‐α −308G/A and −238G/A polymorphisms are associated with increased risks of sepsis: evidence from an updated meta‐analysis

Previous studies have reported the relationship between tumor necrosis factor‐α (TNF‐α) ?308G/A and ?238G/A polymorphisms and sepsis risk with inconsistent results. The aim of this study was to estimate the association of the two polymorphisms with risk of sepsis or sepsis‐related mortality using a meta‐analysis. PubMed, Embase, and Web of Science databases were searched up to June 20 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effect model. Twenty‐six studies were included in this meta‐analysis. Overall, an increased sepsis risk of TNF‐α ?308G/A was observed (GA vs GG: OR = 1.43, 95% CI: 1.07–1.92; GA/AA vs GG: OR = 1.42, 95% CI: 1.06–1.89). Subgroup analyses showed that the significant association was found in Asians (GA vs GG: OR = 1.63, 95% CI: 1.01–2.63) and adult patients. Similarly, an increased sepsis risk of TNF‐α ?238G/A was observed in overall and subgroup analyses. However, no significant association was found between TNF‐α ?308G/A and ?238G/A polymorphisms and sepsis‐related mortality. These findings indicate that both TNF‐α ?308G/A and ?238G/A polymorphisms were associated with increased risks of sepsis but not sepsis‐related mortality. Further studies with larger sample size are needed to confirm these results.     

Association of Interleukin‐1 beta and tumor necrosis factor‐alpha genetic polymorphisms with gastric cancer in India

Interleukin 1 beta (IL‐1β) and Tumor necrosis factor alpha (TNF‐α) are key inflammatory cytokines whose polymorphisms have been correlated with increased susceptibility to gastric cancer (GC). Since geographical and racial differences exist in cancer rates, our study was aimed to evaluate the first possible association of polymorphisms in these genes with GC risk in West Bengal, India. Polymorphisms in IL‐1β and TNF‐α genes were genotyped in 120 GC patients and 135 healthy individuals. Combined effect of the SNPs in both genes with GC risk was determined through allele dosage analysis (ADA) and the survival data were analyzed by Log Rank Test. The study results revealed that IL‐1β rs1143627: T > C, rs16944: C > T (p = 0.001;OR = 1.85; 95% CI 1.30‐2.63) and rs1143633: G > A (p < 0.0001; OR = 2.53; 95% CI 1.67‐3.83) and TNF‐α rs1800630: C > A, rs1799964: T > C (p < 0.0001; OR = 2.31; 95% CI 1.54‐3.46) polymorphisms significantly contributed toward GC risk. Moreover, ADA showed that carriage of 7 “effective” risk alleles conferred a risk of almost 10‐fold in comparison to individuals carrying less than 3 “effective” risk alleles. Our survival analysis also indicated a significant association between IL‐1β rs1143627: T > C and rs16944: C > T and patient survivability. The presence of H. pylori enhanced the risk in individuals with IL‐1β rs1143627:CC and rs16944:TT genotypes. Further, meta‐analysis revealed significant association of IL‐1β rs1143627: T > C (p = 0.026; OR = 4.165; 95% CI 1.18‐14.65) and rs16944: C > T (p = 0.01; OR = 5.49; 95% CI 1.48‐20.37) in presence of H. pylori with gastric cancer in Asian population though no significant difference (p > 0.05) was found when compared to absence of H. pylori Environ. Mol. Mutagen. 59:653–667, 2018. © 2018 Wiley Periodicals, Inc.     

Association of tumour necrosis factor‐alpha G/A ‐238 and G/A ‐308 single nucleotide polymorphisms with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disorder of unknown origin. As proinflammatory cytokines are known to contribute towards the pathogenesis of JIA, this case–control study was performed to examine the associations of certain single nucleotide polymorphisms (SNPs) of tumour necrosis factor‐α (TNF‐α) gene. Fifty‐three patients with JIA participated in this study as patients group and compared with 137 healthy unrelated controls. Genotyping was performed for TNF‐α gene at positions ‐308 and ‐238, using polymerase chain reaction with sequence‐specific primers method. Results of the analysed data revealed a significant positive association for TNF‐α gene at positions ‐308 and ‐238 for A allele in patients group compared with controls (P < 0.01). At the genotypic level, the frequency of TNF‐α gene at positions ‐308 and ‐238 for GG genotype was discovered to be higher in the patients with JIA compared to the healthy controls (P < 0.01), while GA genotype at the same positions was observed to be less frequent in the case group than the controls (P < 0.01). At the haplotypic level, a significant positive association for TNF‐α GG haplotype (positions ‐308, ‐238) together with a notable negative association for TNF‐α AG and GA haplotypes at the same positions were detected in the patients group in comparison with the healthy individuals (P < 0.01). Cytokine gene polymorphisms might affect the development of JIA. Particular TNF‐α gene variants could render individuals more susceptible to JIA..     

Association of the IL‐10 receptor A536G (S138G) loss‐of‐function variant with multiple sclerosis in Tunisian patients

Interleukin‐10 (IL‐10), a potent anti‐inflammatory T‐cell cytokine, has been shown to be a regulatory cytokine that is associated with disease remission in multiple sclerosis (MS) and exerts its activity through its cognate cell surface receptor complex, IL‐10 receptor 1 (IL‐10R1) and IL‐10R2. The purpose of this study was to investigate the IL‐10R1 S138G loss‐of‐function polymorphism (A536G: rs3135932) for possible influence on susceptibility and outcome of MS in Tunisian patients. A total of 103 Tunisian MS patients and 160 control subjects were studied. Genomic DNA samples were extracted from leukocytes and used to investigate S138G polymorphism in IL‐10R1 gene by multiplex allele‐specific polymerase chain reaction. Associations between G allele [odds ratio (OR) = 5.57; 95% confidence intervals (CI) = 3.26–9.54; p = 10^?7], GG genotypes [OR = 10.41; 95% CI = 2.28–47.58; p = 0.0007] and AG genotype [OR = 4.14; 95% CI = 2.16–7.93; p = 0.000016] with the risk development of MS were found. In contrast, the AA genotype seemed to be associated with protection against MS [OR = 0.17; 95% CI = 0.09–0.30; p = 10^?7]. No association was found between S138G SNP and clinical features or disease activity of MS patients. In conclusion, our results suggest that S138G loss‐of‐function polymorphism of the IL‐10R1 may be important risk factor in increasing susceptibility to MS.     

Association of interleukin‐18 promoter polymorphisms with chronic obstructive pulmonary disease in male smokers

Chronic obstructive pulmonary disease (COPD) is considered a complex genetic disorder and it is expected that many genes play a role in the pathogenesis of this disease. Previous studies have reported that several variations within the interleukin (IL)‐18 gene promoter region have been associated with different inflammatory diseases such as asthma. However, the association of IL‐18 promoter polymorphisms with COPD has not been studied yet. We then performed a prospective case–control study to explore this association in male smokers of Chinese Han people. Our study recruited 112 COPD cases and 105 healthy controls matched for age. The genotyping of IL‐18 promoter polymorphisms (‐607 C/A and ‐137 G/C) was performed using TaqMan single nucleotide polymorphism genotyping assays. The frequencies of the alleles and genotypes in patients and controls were compared. We found that the frequency of IL‐18 ‐607 C allele was significantly increased in patients with COPD (odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.01–2.15, P = 0.04). The frequency of IL‐18 ‐607 C allele was significantly higher in the GOLD (Global initiative for Obstructive Lung Disease) 3–4 group compared with the GOLD 1–2 group (OR=2.06, 95% CI = 1.21–3.51, P = 0.01). There were no significant differences in the frequencies of the alleles and genotypes of IL‐18 ‐137 G/C polymorphism between the patients and healthy smokers or between GOLD 3–4 group and GOLD 1–2 group. Our study revealed that the IL‐18 ‐607 C/A polymorphism was associated with COPD susceptibility and severity of airflow limitation in male smokers of Chinese Han people.     

Association between the Interleukin‐6 Gene −572 C/G Polymorphism and the Risk of Type 2 Diabetes Mellitus: A Meta‐Analysis of 11,681 Subjects

The association between the interleukin‐6 (IL‐6) gene ?572 C/G (rs1800796) polymorphism and type 2 diabetes mellitus (T2DM) risk remains controversial. Thus, we performed this meta‐analysis by searching PubMed, Embase, Web of Science, CBMdisc and CNKI databases until January 30, 2012. In addition, hand searching of the references of identified articles was performed. A total of 10 case–control studies including 11,681 subjects were selected to evaluate the possible association. Our results showed evidence for significant association between the IL‐6 gene ?572 C/G polymorphism and T2DM risk (for G allele vs. C allele: odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.09–1.52, P = 0.002, P = 0.008 after Bonferroni testing; for G/G vs. C/C: OR = 1.89, 95% CI = 1.51–2.37, P < 0.00001, P < 0.00004 after Bonferroni testing; for GG vs. G/C + C/C: OR = 1.75, 95% CI = 1.20–2.56, P = 0.004, P = 0.016 after Bonferroni testing; for G/G + G/C vs. C/C: OR = 1.32, 95% CI = 1.11–1.57, P = 0.001, P = 0.004 after Bonferroni testing). In addition, similar results were obtained in the subgroup analysis based on ethnicity. In summary, the present meta‐analysis suggests a significant association between the IL‐6 gene ?572 G allele and increased risk of T2DM.     

Association of the Vascular Endothelial Growth Factor Gene Polymorphisms (–460C/T, +405G/C and +936T/C) with Endometriosis: A Meta‐Analysis

Published data on the association between the vascular endothelial growth factor (VEGF) gene –460C/T (rs833061), +405G/C (rs2010963), +936T/C (rs3025039) polymorphisms and endometriosis risk are inconclusive. Eleven eligible case‐control studies including 2690 cases and 2803 controls were included in this meta‐analysis through searching the databases of PubMed and CBMdisc (up to August 1, 2011). In the overall analysis, no significant association between the –460C/T and +405G/C polymorphisms and risk of endometriosis was observed. However, significant associations were observed between endometriosis risk and VEGF+936T polymorphism with summarized odds ratio of 1.19 (95%CI, 1.02–1.37), 1.18 (95%CI, 1.03–1.37), 1.15 (95%CI, 1.01–1.30) for CT versus CC genotype, dominant mode (CT/TT vs. CC) and allele comparison (T vs. C), respectively. Furthermore, stratified analysis showed that significantly strong association between +936T/C polymorphism and endometriosis was present only in stage III–IV (OR = 1.32 for dominant mode; OR = 1.30 for T vs. C), but not in stage I–II. However, no significantly increased risk of endometriosis was found in any of the genetic models in Asians or in Caucasians. This meta‐analysis supports that VEGF+936T/C polymorphism is capable of causing endometriosis susceptibility.     

Association of Interleukin 10 Gene Polymorphisms with Autoimmune Thyroid Disease: Meta‐Analysis

The aim of this study was to perform a meta‐analysis of eligible studies and to derive a precise estimate of the association between interleukin 10 (IL10) polymorphisms and susceptibility to autoimmune thyroid disease (AITD). Meta‐analyses were conducted on the associations between AITD and the ‐1082 G/A (rs1800896), ‐819 C/T (rs1800871) and ‐592 C/A (rs1800872) polymorphisms in IL10, and the haplotype of these polymorphisms and AITD. A total of 2903 AITD patients and 3060 controls in 10 eligible studies were included in the meta‐analysis. This meta‐analysis showed significant associations between IL10 at the ‐1082 G allele and overall AITD (OR: 1.44, 95% CI 1.13–1.82, P = 0.003), but no association between the IL10 ‐592 C allele and the ‐819 C allele and AITD. Subgroup studies demonstrated significant associations between the ‐1082 G allele and susceptibility to Graves’ disease. Ethnicity‐specific meta‐analysis revealed significant associations between the ‐1082 G allele and AITD susceptibility in Asian populations; however, in Middle Eastern populations, no association was evident. Meta‐analysis of the IL10 haplotype revealed an association between the ATA haplotype and AITD (OR: 1.17, 95% CI 1.00–1.36, P = 0.04). Meta‐analysis demonstrates that the IL10 polymorphisms are associated with susceptibility to AITD.     

Interleukin 17A genetic variations and susceptibility to non‐small cell lung cancer

Lung cancer is the leading cause of cancer‐related death, in which non‐small cell lung cancer (NSCLC) is the most common type. Evidence have shown that interleukin 17 (IL‐17) greatly involves in human immune responses. In this study, we investigated the effect of IL‐17 on NSCLC by examining the association between IL‐17A genetic polymorphisms and the susceptibility to NSCLC. IL‐17A ‐420A/G and IL‐17A ‐73G/A polymorphisms were detected in 330 NSCLC patients and 382 healthy controls. We found that subjects carrying ?73GA genotype or AA genotype had 2.09‐fold or 2.52‐fold increased risk of NSCLC than those with ?73GG genotype [odds ratio (OR) = 2.09, 95% confidence interval (CI), 1.46 – 2.98, p < 0.001; OR = 2.52, 95% CI, 1.30–4.88, p = 0.005, respectively). However, the IL‐17A ‐420A/G did not reveal any correlation with the cancer. Further investigation showed that prevalence of IL‐17A ?73GA genotype and A allele were significantly increased in adenocarcinoma patients (OR = 1.75, 95% CI, 1.08–2.86, p = 0.024, OR = 1.57, 95% CI, 1.09–2.28, p = 0.016, respectively). We also evaluated the effect of the polymorphisms on gene expression, and identified that peripheral blood mononuclear cells with IL‐17A ‐73GA and AA genotypes produced significantly higher level of IL‐17 than the cells with IL‐17A ‐73GG genotype. Our results suggest that IL‐17A ‐73G/A genetic variations may upregulate IL‐17 expression and are associated with increased susceptibility to NSCLC.     

Association of Thrombomodulin Gene Polymorphisms with Susceptibility to Atherosclerotic Diseases: A Meta‐Analysis

Previous studies have proved that the dysfunction of thrombomodulin (TM) plays an important role in the pathogenesis of atherosclerotic diseases. In order to reveal their inherent relationship, we conducted a meta‐analysis to uncover the association between two polymorphisms ‐33G/A and Ala455Val (c.1418C>T) in the TM gene and atherosclerotic diseases. We carried out a systematic search in PubMed, Science Direct, BIOSIS Previews, SpringerLink, the Cochrane library, the Chinese National Knowledge Infrastructure, the Chinese Biomedical Database, the Wei Pu database, and the Wanfang Database. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were computed to show the association. We included 22 eligible studies which involved 5472 patients and 7786 controls. There were statistically significant associations between ‐33G/A polymorphisms in TM and the MI group under the Allele and Recessive models in Asians (G vs. A: OR = 0.67, 95%CI = 0.56–0.78, P < 0.00001; GG vs. GA+AA: OR = 0.66, 95%CI = 0.56–0.78, P < 0.00001). However, these findings of the overall and subgroups showed that Ala455Val polymorphisms did not have any relationship with atherosclerotic diseases. After Bonferroni correction, the above associations remained statistically significant. This meta‐analysis provides robust evidence of association between the ‐33G/A polymorphism in the TM gene and the risk of myocardial infarction in Asians. The A allele may increase the incidence of MI in Asians. However, the Ala455Val variant was not associated with atherosclerotic risk. Further studies with adequate sample size are needed to verify our findings.     

Association of Monocyte Chemoattractant Protein‐1 (MCP‐1)‐2518A>G Polymorphism with Susceptibility to Coronary Artery Disease: A Meta‐Analysis

We attempted to systematically elucidate the association between monocyte chemoattractant protein‐1 (MCP‐1) ‐2518A>G polymorphism and risk of coronary artery disease (CAD). Eligible studies were identified through PubMed, EBSCO, and Web of Science Databases. The magnitude of MCP‐1 polymorphism effect and its possible mode of action on CAD were estimated. The odds ratio (OR) with 95% confidence intervals (CI) were pooled in a specific genetic model to assess the association. A total of 21 studies were involved. There was significant gene effect on CAD risk in the overall population (likelihood ratio test: p < 0.0001). Patients with GG and AG genotypes had 1.435 (95% CI: 1.183–1.740) and 1.087 (95% CI: 1.008–1.172) times higher risk of CAD than those with AA genotype. These gene effects suggested a recessive model to be appropriate. The pooled OR was 1.362 (95% CI: 1.137–1.631; p_uncorrected = 0.001, p_FDR = 0.005) in the recessive model. In the ethnicity‐stratified analysis, significant association was observed in the Caucasian population (OR = 1.492; 95% CI: 1.106–2.014; p_uncorrected = 0.009, p_FDR = 0.015), whereas no statistical significant association was detected in the Asian population (adjusted p = 0.124). The results suggested that MCP‐1 ‐2518A>G polymorphism may be associated with susceptibility to CAD, especially in Caucasians.     

The Role of TLR4, TNF‐α and IL‐1β in Type 2 Diabetes Mellitus Development within a North Indian Population

This study investigated the role of IL‐1β‐511 (rs16944), TLR4‐896 (rs4986790) and TNF‐α‐308 (rs1800629) polymorphisms in type 2 diabetes mellitus (T2DM) among an endogamous Northern Indian population. Four hundred fourteen participants (204 T2DM patients and 210 nondiabetic controls) were genotyped for IL‐1β‐511, TLR4‐896 and TNF‐α‐308 loci. The C allele of IL‐1β‐511 was shown to increase T2DM susceptibility by 75% (OR: 1.75 [CI 1.32–2.33]). Having two parents affected by T2DM increased susceptibility by 5.7 times (OR: 5.693 [CI 1.431–22.648]). In this study, we have demonstrated a conclusive association with IL‐1β‐511 locus and IL‐1β‐511‐TLR4‐896 diplotype (CC‐AA) and T2DM, which warrants further comprehensive analyses in larger cohorts.     

The polymorphism ‐2548 G/A in leptin and severity of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by airway obstruction that is not fully reversible, and there is evidence of a hereditary component in COPD. We aimed to determine whether the polymorphisms ‐2548G/A of leptin (LEP) gene were associated with COPD and its severity in Chinese. A total of 456 subjects with COPD and 422 healthy controls from West China Hospital were enrolled in this study. COPD patients had been undergone a spirometry and a physical examination to refer the GOLD I–IV stages. The polymorphisms in the leptin promoter region at position ‐2548 G/A were detected by Polymerase chain reaction‐restriction fragment length polymorphism analysis. The genotypes and alleles were scored, and the frequencies of the alleles and genotypes in patients and controls were compared. A significantly higher risk for COPD was observed for carriers of the LEP ‐2548 AA genotype [odds ratio (OR) = 7.87, 95% confidence interval (CI) 4.19–14.77, P < 0.001] and carriers of the LEP ‐2548 GA genotype (OR = 2.98, 95% CI 1.57–5.66, P = 0.001). The LEP ‐2548 A allele: frequency was significantly higher in the patient group compared with the control group (OR = 2.75, 95% CI: 2.20–3.44, P < 0.001). We also found a significant relationship between leptin gene polymorphism and the severity of COPD. In the present case–control study, we found an association between the ‐2548 G/A variant of the leptin gene and pathogenesis, severity of COPD in the Chinese population. It suggests that leptin ‐2548 G/A should be used as a genetic marker of COPD severity.     

Corticosteroid enhances TNF‐α‐mediated leukocyte adhesion to pulmonary microvascular endothelial cells

Background: Some severe asthma patients are characterized by elevated levels of tumor necrosis factor alpha (TNF‐α) and neutrophilic inflammation in the airways. Although such phenotypic changes in asthma might contribute to corticosteroid refractoriness, the role of TNF‐α in the process remains unclear. TNF‐α exerts its biological effects mainly by acting on the vascular endothelium, and thereby upregulates leukocyte recruitment into inflamed tissues. The aim of this study was to investigate the effects of dexamethasone (DEX) on the TNF‐α‐mediated responses of human microvascular endothelial cells from lung blood vessels (HMVEC‐LBl) in vitro. Methods: HMVEC‐LBl were cultured with TNF‐α in the presence and absence of DEX. The effects of DEX on various TNF‐α‐mediated responses, such as the expressions of chemokines and cellular adhesion molecules, leukocyte adhesion were determined. Results: TNF‐α significantly induced growth‐related oncogene alpha (GRO‐α), interleukin 8 (IL‐8), regulated on activation, normal T‐cell expressed and secreted (RANTES) and interferon‐inducible protein 10 (IP‐10) productions and cell surface expressions of intracellular adhesion molecule 1 (ICAM‐1) and vascular cell adhesion molecule 1 (VCAM‐1) on HMVEC‐LBl. TNF‐α‐induced GRO‐α and IL‐8 were slightly attenuated by DEX treatment (reaches to 89% and 79%, respectively), whereas expressions of IP‐10, ICAM‐1 and VCAM‐1 were significantly enhanced by the same treatment (up to 172%, 152% and 139%, respectively). Correspondingly, in vitro adhesion of eosinophils and neutrophils to TNF‐α‐treated HMVEC‐LBl were significantly enhanced by DEX. Conclusions: Some proinflammatory effects of DEX, a corticosteroid, were found in TNF‐α‐mediated in vitro reactions of pulmonary microvascular endothelial cells, i.e. chemokine productions and leukocyte adhesion. These in vitro results may explain, at least in part, the corticosteroid refractoriness accompanied by a marked increase in TNF‐α production that is seen in severe asthmatic patients.     

Association of Cytokine Gene Polymorphisms in Patients with Tuberculosis and Their Household Contacts

Cytokine gene polymorphisms are known to be associated with functional differences in cytokine regulation and may affect host susceptibility to tuberculosis (TB). Contacts are important group in developing tuberculosis infection and are 10–60 times more likely to develop TB than general population. The present study was carried out in patients with TB (N = 176), their household contacts (HHC; N = 155) from Free Chest TB Clinic PPM DOTS (1TU) covering 500,000 population at Mahavir Hospital and Research Centre, Hyderabad, and healthy controls (HC; N = 170) also included. The association of single‐nucleotide polymorphisms (SNPs) in the promoter region of TNF‐α (?308G/A), IL‐2 (?330T/G), IL‐4 (?589C/T) and in exon region of TGF‐β1 (+869T/C) genes was assessed by ARMS & PCR‐RFLP using specific primers in the above‐mentioned subjects. The differences in allelic or genotypic frequencies of TNF‐α (?308G/A) between patients, their HHC and HC were not statistically significant (P > 0.05). IL‐2 (?330T/G) TG genotype was significantly different between patients, HHC compared to HC (P < 0.002, OR‐1.997, 95%CI‐1.260‐3.168, P < 0.03, OR‐1.602, 955CI‐1.003‐2.561).IL‐4 (?589C/T) CC genotype was significantly different between patients and HC (P < 0.03, OR‐1.791, 95%CI‐1.009‐3.189) as well as between HHC and HC at P < 0.0001, OR‐2.56, 95%CI‐1.448‐4.545. In addition, the TGF‐β 1 (+869T/C) TC genotype was significantly associated with susceptibility to tuberculosis in patients when compared against HC(P < 0.0001, OR‐3.416, 95%CI‐2.063‐5.670) and HHC (P < 0.0001, OR‐2.357, 95%CI‐1.439‐3.868), respectively.MDR analysis indicated that TT genotype of TGF‐β1 with TT and CT genotypes of IL‐4 showed high risk with GA, TT genotypes of TNF‐α, IL‐2, respectively. Our results suggest that IL‐2 (‐330T/G), IL‐4 (‐589 C/T) and TGF‐β1 (+869T/C) gene polymorphisms may be associated with TB susceptibility.     

Chronic exposure of interleukin‐13 suppress the induction of matrix metalloproteinase‐1 by tumour necrosis factor α in normal and scleroderma dermal fibroblasts through protein kinase B/Akt

Peripheral blood mononuclear cells taken from patients with scleroderma express increased levels of interleukin (IL)‐13. Moreover, the expression of matrix metalloproteinase‐1 (MMP‐1) from involved scleroderma skin fibroblasts is refractory to stimulation by tumour necrosis factor (TNF)‐α. To elucidate the mechanism(s) involved, we examined the effect of IL‐13 on TNF‐α‐induced MMP‐1 expression in normal and scleroderma human dermal fibroblast lines and studied the involvement of serine/threonine kinase B/protein kinase B (Akt) in this response. Dermal fibroblast lines were stimulated with TNF‐α in the presence of varying concentrations of IL‐13. Total Akt and pAkt were quantitated using Western blot analyses. Fibroblasts were treated with or without Akt inhibitor VIII in the presence of IL‐13 followed by TNF‐α stimulation. MMP‐1 expression was analysed by real‐time polymerase chain reaction (PCR) and enzyme‐linked immunosorbent assay (ELISA). Statistical analysis was performed using analysis of variance (anova ) or Student's t‐test. Upon TNF‐α stimulation, normal dermal fibroblasts secrete more MMP‐1 than systemic sclerosis (SSc) fibroblasts. This increase in MMP‐1 is lost when fibroblasts are co‐incubated with IL‐13 and TNF‐α. IL‐13 induced a significant increase in levels of pAkt in dermal fibroblasts, while Akt inhibitor VIII reversed the suppressive effects of IL‐13 on the response of cultured fibroblasts to TNF‐α, increasing their expression of MMP‐1. We show that IL‐13 suppresses MMP‐1 in TNF‐α‐stimulated normal and scleroderma dermal fibroblast. Akt inhibitor VIII is able to reverse the suppressive effect of IL‐13 on MMP‐1 expression and protein synthesis. Our data suggest that IL‐13 regulates MMP‐1 expression in response to TNF‐α through an Akt‐mediated pathway and may play a role in fibrotic diseases such as scleroderma.     

Synergistic effect of interleukin‐17 and tumour necrosis factor‐α on inflammatory response in hepatocytes through interleukin‐6‐dependent and independent pathways

The proinflammatory cytokines interleukin (IL)‐17 and tumour necrosis factor (TNF)‐α are targets for treatment in many chronic inflammatory diseases. Here, we examined their role in liver inflammatory response compared to that of IL‐6. Human hepatoma cells (HepaRG, Huh7.5 and HepG2 cells) and primary human hepatocytes (PHH) were cultured with IL‐6, IL‐17 and/or TNF‐α. To determine the contribution of the IL‐6 pathway in the IL‐17/TNF‐α‐mediated effect, an anti‐IL‐6 receptor antibody was used. IL‐17 and TNF‐α increased in synergy IL‐6 secretion by HepaRG cells and PHH but not by Huh7.5 and HepG2 cells. This IL‐17/TNF‐α synergistic cooperation enhanced the levels of C‐reactive protein (CRP) and aspartate aminotransferase (ASAT) in HepaRG cell and PHH cultures through the induction of IL‐6. IL‐17/TNF‐α also up‐regulated IL‐8, monocyte chemoattractant protein (MCP)‐1 and chemokine (C‐C motif) ligand 20 (CCL20) chemokines in synergy through an IL‐6‐independent pathway. Interestingly, first exposure to IL‐17, but not to TNF‐α, was crucial for the initiation of the IL‐17/TNF‐α synergistic effect on IL‐6 and IL‐8 production. In HepaRG cells, IL‐17 enhanced IL‐6 mRNA stability resulting in increased IL‐6 protein levels. The IL‐17A/TNF‐α synergistic effect on IL‐6 and IL‐8 induction was mediated through the activation of extracellular signal‐regulated kinase (ERK)‐mitogen‐activated protein kinase, nuclear factor‐κB and/or protein kinase B (Akt)–phosphatidylinositol 3‐kinase signalling pathways. Therefore, the IL‐17/TNF‐α synergistic interaction mediates systemic inflammation and cell damage in hepatocytes mainly through IL‐6 for CRP and ASAT induction. Independently of IL‐6, the IL‐17A/TNF‐α combination may also induce immune cell recruitment by chemokine up‐regulation. IL‐17 and/or TNF‐α neutralization can be a promising therapeutic strategy to control both systemic inflammation and liver cell attraction.     

Correlation between polymorphisms at interleukin‐6 but not at interleukin‐10 promoter and the risk of human T lymphotropic virus type I‐associated myelopathy/tropical spastic paraparesis in Brazilian individuals

HTLV‐1 is the etiologic agent of ATL and HAM/TSP. The majority of HTLV‐1‐infected individuals remain asymptomatic, indicating that the infection alone is not sufficient to cause the diseases. It has been reported that cytokine gene polymorphisms, including polymorphisms at IL‐6 and IL‐10 gene, might be important. We analyzed SNP in the promoter region of the IL‐6: ?174, ?572, ?597, and ?634 positions, and IL‐10: ?592 position to evaluate the role of these polymorphisms in the HAM/TSP pathogenesis in 133 HTLV‐1 infected individuals and in 100 healthy individuals from Salvador, Bahia, Brazil. The ?634C allele frequencies were higher among HAM/TSP patients (21.2%) than among oligosymptomatic (6.5%; P = 0.038) and asymptomatic (9.5%; P = 0.025) subjects. Similarly, the ?174G allele frequencies were higher in HAM/TSP patients than in oligosymptomatic patients (P = 0.02). Moreover, the ?634GC/?174GG genotype combination was identified at a higher frequency (38.5%) in the HAM/TSP patients than in subjects with other clinical status (8.7%; P = 0.016 for oligosymptomatic and 15.5%, P = 0.012 for asymptomatic patients). However, the multivariate logistic regression including the genotypes of the three studied loci showed that only ?634 C IL‐6 carriers remain as significant and independent TSP/HAM predictor (odds ratio [OR] = 5.31; 95% [CI] = 1.60–17.56; P = 0.006). We suggest that ?634 G C in IL‐6 could contribute to HAM/TSP development and that identification of the collective influence of several cytokine polymorphisms, their prevalence, and their interaction could help to better understand this disease. J. Med. Virol. 80:2141–2146, 2008. © 2008 Wiley‐Liss, Inc.     

‐318C/T polymorphism of the CTLA‐4 gene is an independent risk factor for RBC alloimmunization among sickle cell disease patients

Cytotoxic T‐lymphocyte‐associated antigen 4 (CTLA‐4) molecule is expressed on T‐lymphocyte membrane and negatively influences the antigen‐presenting process. Reduced expression of CTLA‐4 due to gene polymorphisms is associated with increased risk of autoimmune disorders, whose physiopathology is similar to that of post‐transfusion red blood cell (RBC) alloimmunization. Our goal was to evaluate if polymorphisms of CTLA‐4 gene that affect protein expression are associated with RBC alloimmunization. This was a case–control study in which 134 sickle cell disease (SCD) patients and 253 non‐SCD patients were included. All patients were genotyped for the polymorphisms 49A/G and ‐318C/T of CTLA‐4 gene. The genotype frequency of ‐318C/T differed significantly between alloimmunized and nonalloimmunized SCD patients, irrespective of clinical confounders (p = .016). SCD patients heterozygous for ‐318T allele presented higher risk of alloantibody development (OR: 5.4, CI: 1.15–25.6). In conclusion, the polymorphism ‐318C/T of CTLA‐4 gene is associated with RBC alloimmunization among SCD patients. This highlights the role played by CTLA‐4 on post‐transfusion alloantibody development.