Increased Susceptibility To Systemic Lupus Erythematosus Research Articles

Lupus susceptibility region containing CTLA4 rs17268364 functionally reduces CTLA4 expression by binding EWSR1 and correlates IFN-\u03b1 signature

BackgroundDysregulation of T cells mediated immune responses is a hallmark in the development of systemic lupus erythematosus (SLE). Recent genome wide association study (GWAS) revealed the genetic contribution of variants located in the cytotoxic T lymphocyte-associated protein-4 (CTLA4)-inducible T cell co-stimulator (ICOS) intergenic region to SLE susceptibility. Our aim is to find a functional variant in this region.MethodsThe genetic association results in the CTLA4-ICOS region from previous GWAS were adopted to select the potential variant which was further replicated in two independent cohorts (Henan cohort 2053 SLE patients and 1845 healthy controls, Beijing cohort 2303 SLE patients and 19,262 healthy). In order to explore the functional significance in SLE, bioinformatics with validation experiments (including electrophoretic mobility shift assay and luciferase reporter assay) and mRNA expression analysis were also performed.ResultsA variant located in the CTLA4-ICOS intergenic region, rs17268364, was associated with susceptibility to SLE patients in Chinese populations (risk allele, pmeta = 7.02×10−11, OR 1.19, 95%CI 1.13–1.26). The bioinformatics suggested that rs17268364 might affect the expression of CTLA4, not ICOS. The rs17268364 risk G allele containing sequence reduced the expression of the reporter gene by binding transcriptional repressor Ewing sarcoma breakpoint region 1 (EWSR1). Following genotype-mRNA expression, the analysis also showed the risk allele of rs17268364 was associated with low CTLA4 expression in lupus nephritis (LN) patients. Healthy individuals carrying rs17268364 risk G allele was significantly correlated with higher levels of IFN-α signature including increased lymphocyte antigen 6E (LY6E) (p=0.031), interferon-stimulated gene 15 (ISG15) (p=0.038), interferon regulatory factor 9 (IRF9) (p=0.028), and interferon regulatory factor 5 (IRF5) (p=0.040) mRNA expression.ConclusionsThe present study confirmed the functional role of rs17268364 in the CTLA4-ICOS intergenic region that increased SLE susceptibility in the Chinese population.

Single Nucleotide Polymorphisms in PPARD Associated with Systemic Lupus Erythematosus in Chinese Populations.

Background Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease characterized by apoptotic clearance deficiency provoking autoimmune responses and leading to multiple organ damage. PPAR-δ, encoded by the PPARD gene, was induced in macrophages promoting the timely disposal of apoptotic cells. Biological studies had provided solid foundation of PPARD involvement in SLE; it is worthwhile to further explore the genetic contribution of PPARD to SLE. Methods We performed a discovery-replication genetic association study. The discovery study was based on previous reported GWAS data. And the replication study was conducted in 1003 SLE patients and 815 healthy controls from Henan, Middle East of China. Further, we analyzed the eQTL effect to identify possible functional significance. Results In the genetic association analysis, we observed significant association between the risk C allele of rs4713853 (p = 0.03, OR 1.167, 95% CI 1.015-1.341) and increased SLE susceptibility. Moreover, individuals with the risk C allele were associated with lower expression of PPARD and DEF6. Our clinical analysis showed that SLE patients with the risk C allele of rs4713853 were more likely to present a higher proportion of anti-Sm antibody presence (CC+CT vs. TT, 20.0% vs. 14.2%, p = 0.039) and higher level of Scr (median inter quarter range CC+CT vs. TT, 56 48-71 vs. 54 46-64 μmol/L, p = 0.002). Conclusions In conclusion, our study identified a novel association between PPARD rs4713853 and SLE susceptibility in Chinese populations. By integrating multiple layers of analysis, we suggested that PPARD might be a main candidate in the pathogenesis of SLE.

Association between PPP2CA polymorphisms and clinical features in southwest Chinese systemic lupus erythematosus patients.

Increasing evidence supports the involvement of a catalytic subunit (PP2Ac) of protein phosphatase 2A (PP2A) in the mechanisms of systemic lupus erythematosus (SLE). This study was conducted to explore the association single nucleotide polymorphisms (SNPs) of PPP2CA with SLE susceptibility, serum cytokines levels, and clinical features in a Chinese Han population. A case–control association study was carried out in 1509 Chinese Han subjects (730 SLE patients and 779 healthy individuals). Genotyping for genetic variants of PPP2CA (rs10491322 and rs7704116) was performed using a polymerase chain reaction-high resolution melting (PCR-HRM) assay. In the cohort of SLE patients, we observed that rs10491322 and rs7704116 were positively increased SLE susceptibility (OR = 1.61, 95% CI = 1.13–2.31, P = .009; OR = 1.59, 95% CI = 1.17-2.15, P = .003, respectively). Interestingly, the AG genotype of rs10491322 carriers presented higher IL-6 (P < .001) and IL-17 (P < .001) than those with AA genotype carriers. Specifically, carriage of the rs10491322 G∗ allele led to a higher prevalence of arthritis in SLE patients (P = .01). This study demonstrated an association of PPP2CA (rs10491322 and rs7704116) with SLE susceptibility in a Chinese Han population. Furthermore, the minor allele of PPP2CA rs10491322 as a risk factor was correlated with immunologic disorders for SLE.

G-protein coupled-receptor 65 5´UTR gene polymorphism in the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with unknown etiology. G-protein-coupled receptor 65 (GPR65) candidates as an SLE-locus for functioning in T cell receptor-mediated self-reactive T cell death in the thymus. This is also involved in anti-inflammatory actions and apoptosis as remarkable features of autoimmune diseases. This study investigated the relationship between the rs10139328 polymorphism at the 5´UTR of a GPR65 gene and SLE. This case-control study consisted of 102 SLE patients (98 females, 4 males) and 118 age- and gender-matched healthy controls (113 females, 5 males). Genotyping of the rs10139328 polymorphism was determined using an amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Data was analyzed using SPSS software. The Pearson chi-square was the test of choice for assessing the association between the rs10139328 polymorphism and SLE. The probable influences of sunlight and family history on SLE were evaluated by performing logistic regression. Except for one heterozygote subject among the control group, the study population was homozygote for the selected polymorphism. No statistical difference was seen in genotype distribution between the cases and the controls (P> 0.05). Statistical analysis revealed that sun exposure directly increased SLE susceptibility (P < 0.001). Having a family history of SLE increased the risk of disease occurrence by more than two times (OR = 2.38, 95% CI: 1.28 - 4.41, P= 0.006). The results of the current study do not support the importance of the studied polymorphism in a GPR65 gene in the pathogenesis of SLE among southwestern Iranian patients.

Meta-analysis of associations of IL1 receptor antagonist and estrogen receptor gene polymorphisms with systemic lupus erythematosus susceptibility.

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects a number of different organs and tissues. Interleukin-1 (IL1) and estrogen are considered potential elements in the pathology of SLE. Recently, the variable number of tandem repeats (VNTR) polymorphism in the IL1 receptor antagonist gene (IL1-RN) and PvuII (rs2234693) and XbaI (rs9340799) polymorphisms in the estrogen receptor 1 gene (ESR1) have been associated with a predisposition to SLE. However, the evidence for these associations is inconclusive. We therefore conducted a meta-analysis to validate the roles of these polymorphisms in SLE susceptibility. We searched four databases and identified a total of 17 eligible articles comprising 24 studies. The Newcastle-Ottawa quality assessment scale was used to assess the qualities of the selected studies. We assessed the strengths of the associations using odds ratios (ORs) with 95% confidence intervals (95% CIs). Regarding the IL-1RN VNTR, the 2 allele significantly increased SLE susceptibility (2 vs. L: OR = 1.34, 95% CI = 1.03–1.73, P = 0.03). The ESR1 PvuII CC/CT genotype was also associated with SLE susceptibility (CC/CT vs. TT: OR = 1.25, 95% CI = 1.06–1.47, P = 0.01), and the difference was especially pronounced among Asians (CC/CT vs. TT: OR = 1.33, 95% CI = 1.04–1.69, P = 0.02). No significant association between the ESR1 XbaI polymorphism and SLE susceptibility was observed in the overall analysis. However, a marginally significant association between the GG/GA genotype was found in individuals of Asian descent (GG/GA vs. AA: OR = 1.30, 95% CI = 1.01–1.67, P = 0.04). These results indicate that the IL1-RN VNTR 2 allele, ESR1 PvuII CC/CT genotype and ESR1 XbaI GG/GA genotype may increase SLE susceptibility, especially in Asian individuals.

Soluble fas and the -670 polymorphism of fas in lupus nephritis.

This study was performed to clarify the role of soluble Fas (sFas) in lupus nephritis (LN) and establish a potential relationship between LN and the −670 polymorphism of Fas in 67 patients with systemic lupus erythematosus (SLE), including a subset of 24 LN patients with proteinuria. Additionally, a group of 54 healthy subjects (HS) was included. The allelic frequency of the −670 polymorphism of Fas was determined using PCR-RFLP analysis, and sFas levels were assessed by ELISA. Additionally, the WT-1 protein level in urine was measured. The Fas receptor was determined in biopsies by immunohistochemistry (IHC) and in situ hybridization (FISH) and apoptotic features by TUNEL. Results. The −670 Fas polymorphism showed that the G allele was associated with increased SLE susceptibility, with an odds ratio (OR) of 1.86. The sFas was significantly higher in LN patients with the G/G genotype, and this subgroup exhibited correlations between the sFas level and proteinuria and increased urinary WT-1 levels. LN group shows increased expression of Fas and apoptotic features. In conclusion, our results indicate that the G allele of the −670 polymorphism of Fas is associated with genetic susceptibility in SLE patients with elevated levels of sFas in LN with proteinuria.

IL-10 Gene Polymorphisms and Susceptibility to Systemic Lupus Erythematosus: A Meta-Analysis

BackgroundA number of observational studies have been conducted to investigate the association of the IL-10 gene polymorphisms with systemic lupus erythematosus (SLE) susceptibility. However, their results are conflicting.MethodWe searched published case-control studies on the IL-10 polymorphisms and SLE in PubMed, EMBASE and Chinese Biomedical Literature Database. A meta-analysis was conducted using a fixed-effect or random-effect model based on between-study heterogeneity.ResultsA total of 42 studies with 7948 cases and 11866 controls were included in this meta-analysis. Among Caucasians, the CA27 allele of the IL10.G microsatellites (OR 2.38, 95% CI 1.01–5.62), the G allele of the IL-10 -1082G/A polymorphism (G vs. A: OR 1.21, 95% CI 1.02–1.44; GG vs. AA: OR 1.45, 95% CI 1.16–1.82; GG+GA vs. AA: OR 1.16, 95% CI 1.03–1.29) and its associated haplotype -1082G/−819C/−592C (OR 1.25, 95% CI 1.10–1.42) were associated with increased SLE susceptibility without or with unimportant between-study heterogeneity. Removing studies deviating from Hardy-Weinberg equilibrium (HWE) hardly changed these results. Among Asians, the CA21 allele of the IL-10.G microsatellites (OR 1.28, 95% CI 1.02–1.60) and the -1082G/−819C/−592C haplotype (OR 1.24, 95% CI 1.00–1.53) were associated with increased SLE susceptibility, but with substantial between-study heterogeneity or sensitive to HWE status. Removing studies deviating from HWE also produced statistically significant associations of the IL-10 -1082G/A (GG vs. AA: OR 3.21, 95% CI 1.24–8.28; GG vs. AA+GA: OR 2.85, 95% CI 1.19–6.79) and -592C/A polymorphisms (CC+CA vs. AA: OR 0.69, 95% CI 0.51–0.94) with SLE among Asians.ConclusionThis meta-analysis showed that the IL10.G microsatellites, the IL-10 -1082G/A and -592C/A polymorphisms and the haplotype -1082G/−819C/−592C are associated with SLE susceptibility. Besides, this is the first time to report an association between the CA27 allele of the IL-10.G microsatellites and SLE among Caucasians. Further studies are needed to confirm these findings.

Interferon-gamma gene polymorphisms associated with susceptibility to systemic lupus erythematosus

ObjectiveInterferon-gamma (IFNG) is a type II interferon playing diverse roles in innate and adaptive immune systems. Elevated expression of IFNG has been associated with systemic lupus erythematosus (SLE). This study...