Rui-Xue Leng

Role of microRNA-155 in autoimmunity

MicroRNAs (miRNAs) have recently emerged as a major class of gene expression regulators linked to most biological functions. MiR-155 is encoded within a region known as B cell integration cluster (Bic) gene, identified originally as a frequent integration site for the avian leukosis virus. Disregulation of endogenous miR-155 has been implicated in the pathogenesis of human cancers. Recently, aberrant expression of miR-155 was observed in many autoimmune conditions, including rheumatoid arthritis (RA), multiple sclerosis (MS), and systemic lupus erythematosus (SLE). Moreover, functional analysis demonstrated that miR-155 has powerful regulatory potential in a wide variety of immune cells through targeting specific mRNAs. Since pathogenic immune cells play a pivotal role in pathogenesis of human autoimmune diseases, miR-155 might be a versatile therapeutic target. This review will discuss the current understandings for the role of miR-155 in autoimmunity.

Long noncoding RNAs: novel insights into gastric cancer.

Long non-coding RNAs (lncRNAs) are functional RNAs longer than 200 nucleotides. Recent advances in the non-protein coding part of human genome analysis have discovered extensive transcription of large RNA transcripts that lack coding protein function, termed non-coding RNA (ncRNA). It is becoming evident that lncRNAs may be an important class of pervasive genes involved in carcinogenesis and metastasis. However, the biological and molecular mechanisms of lncRNAs in diverse diseases are not yet fully understood. Thus, it is anticipated that more efforts should be made to clarify the lncRNA world. Moreover, accumulating evidence has demonstrated that many lncRNAs are dysregulated in gastric cancer (GC) and closely related to tumorigenesis, metastasis, and prognosis or diagnosis. In this review, we will briefly outline the regulation and functional role of lncRNAs in GC. Finally, we discussed the potential of lncRNAs as prospective novel targets in GC treatment and biomarkers for GC diagnosis.

Emerging role of long noncoding RNAs in autoimmune diseases.

Long noncoding RNA (lncRNA), with size larger than 200 nucleotides, is a new class of noncoding RNA. Emerging evidence has revealed that lncRNAs play a key role in the regulation of immunological functions and autoimmunity. Herein, we review the recent findings of lncRNA regulation in immune functions and in the development of autoimmunity and autoimmune disease. In addition, we focus on the involvement of lncRNA regulation in innate and adaptive immune responses, immune cell development, and differential expression of lncRNAs in autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes mellitus (T1DM), multiple sclerosis (MS), autoimmune thyroid disease (AITD), psoriasis, polymyositis/dermatomyositis (PM/DM) and Crohns disease (CD).

IL-19, IL-20 and IL-24: potential therapeutic targets for autoimmune diseases

IL-19, IL-20 and IL-24 are members of the IL-10 family of cytokines, the human IL-19, IL-20 and IL-24 genes are all located on the q32 region of chromosome 1, and the three cytokines also share a common receptor IL-20R1/IL-20R2 heterodimer. These cytokines due to the similarity and shared receptor usage, are quite overlapping in function. Recently, the available evidence has indicated that interaction of these cytokines with their receptors might exhibit pro-inflammatory effects on autoimmune diseases, particularly psoriasis and rheumatoid arthritis. Since an imbalance between anti- and pro-inflammatory cytokines contribute to the development of autoimune diseases, these cytokines may be implicated in the pathogenesis of autoimmunity. In this paper, we concisely discuss the biological features of IL-19, IL-20 and IL-24, and focus on their potential roles in autoimmune diseases. Hopefully the information obtained will lead to a better understanding of the pathogenesis and development of novel therapeutic strategies for autoimmune diseases.

Association of IFIH1 rs1990760 polymorphism with susceptibility to autoimmune diseases: A meta-analysis

Abstract Published data on the association between the IFIH1 rs1990760 polymorphism and multiple autoimmune diseases are controversial and inconclusive. To more precisely estimate the association between the IFIH1 rs1990760 polymorphism and susceptibility to autoimmune diseases, a meta-analysis was conducted. Studies examining the association of the IFIH1 rs1990760 polymorphism with autoimmune diseases were exhaustively searched using PubMed, Web of Science and a review of the references. A total of 19 studies with 26 comparisons including 8 type 1 diabetes (T1D), 5 systemic lupus erythematosus (SLE), 5 Graves’ disease (GD), 2 multiple scleorosis (MS), 2 rheumatoid arthritis (RA), 2 Hashimotos thyroiditis (HT), 2 autoimmune Addison’s disease (AAD) were available for this meta-analysis. Meta-analysis was performed for genotype T/T + T/C (dominant model), genotype T/T (recessive model) and T-allele in fixed or random-effects models. The overall odds ratios (ORs) and 95% confidence intervals (CIs) for T-allele were T1D (OR = 1.184, 95% CI = 1.142–1.229), SLE (OR = 1.143, 95% CI = 1.073–1.217), MS (OR = 1.181, 95% CI = 1.062–1.313) and RA (OR = 1.115, 95% CI = 1.004–1.239), respectively. For T1D and SLE, significant association was observed in the population of European ancestry, but not in the Asian population. This meta-analysis demonstrates that the IFIH1 rs1990760 T-allele confers susceptibility to T1D, SLE, MS and RA and suggests that the IFIH1 rs1990760 polymorphism might have no effect on GD and AAD. Our result provides further evidence for the notion of common gene underlying multiple autoimmune diseases.

Subclinical atherosclerosis in patients with systemic lupus erythematosus: A systemic review and meta-analysis

OBJECTIVE Systemic lupus erythematosus (SLE) is associated with increased risk of cardiovascular disease. Carotid intima media thickness (CIMT) and carotid plaques are both frequently used to identify populations at higher cardiovascular risk. A systematic literature search and meta-analysis were performed to evaluate CIMT and carotid plaques difference between SLE patients and normal controls. METHODS The literatures comparing markers of cardiovascular risk (CIMT and prevalence of carotid plaques) in SLE and controls were systematically searched in PubMed, EMBASE and Cochrane databases. The overall mean CIMT difference and pooled odds ratio (OR) for the prevalence of carotid plaques between SLE patients and control groups were calculated by fixed-effects or random-effect model analysis. Meta-regression was performed to explore the potential influencing factors. Publication bias was examined by a funnel plot and Eggers test. RESULTS A total of 80 studies (6085 SLE patients and 4794 controls) were included in the final analysis, 71 studies with data on CIMT (4814 cases and 3773 controls) and 44 studies reporting on the prevalence of carotid plaques (4417 cases and 3528 controls). As compared to controls, SLE patients showed a higher CIMT (WMD: 0.07 mm; 95%CI: 0.06, 0.09; P<0.001), and an increased prevalence of carotid plaques (OR: 2.45; 95%CI: 2.02, 2.97; P<0.001). Meta-regression models showed that traditional cardiovascular risk factors (age, HDL and triglyceride of SLE patients) and lupus related risk factors (as expressed by duration, ESR, SLEDAI and steroids) had a significant influence on CIMT, steroids and triglyceride had significant influence on the prevalence of carotid plaques. CONCLUSIONS Our findings support the current evidence base for an increased cardiovascular burden in SLE patients and support the use of CIMT and carotid plaques in observational studies in SLE patients. The findings are of importance to design more specific prevention and treatment strategies.

Lack of association of interleukin-18 gene promoter −607 A/C polymorphism with susceptibility to autoimmune diseases: a meta-analysis

Objective: Published data on the association between interleukin (IL)-18 gene promoter −607 A/C polymorphism and autoimmune diseases risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Methods: A total of 17 studies, including six studies on type 1 diabetes (T1D), four on rheumatoid arthritis (RA), five on systemic lupus erythematosus (SLE), three on Crohn’s Disease (CD) and three on ulcerative colitis (UC), were available for the meta-analysis. Meta-analysis was performed for genotypes A/A (recessive effect), genotypes A/A + A/C (dominant effect), and A allele in fixed or random-effects models. Results: Overall, no significantly elevated autoimmune diseases risk was found in all genetic models when all studies were pooled into the meta-analysis. The overall odds ratios (ORs) and 95% confidence intervals (CIs) for A-allele were T1D (OR = 0.938, 95% CI = 0.757–1.162), RA (OR = 0.759, 95% CI = 0.540–1.067), SLE (OR = 0.858, 95% CI = 0.609–1.208), CD (OR = 1.159, 95% CI = 0.975–1.379) and UC (OR = 1.170, 95% CI = 0.977–1.402), respectively. In the subgroup analysis by ethnicity, there was still no significant association detected in all genetic models. Conclusions: To date, there is still not enough evidence to indicate the association of IL-18 gene promoter −607 A/C polymorphism and the development of autoimmune diseases.

Gene-gene and gene-sex epistatic interactions of MiR146a, IRF5, IKZF1, ETS1 and IL21 in systemic lupus erythematosus.

Several confirmed genetic susceptibility loci involved in the interferon signaling and Th17/B cell response for SLE in Chinese Han populations have been described. Available data also indicate that sex-specific genetic differences contribute to SLE susceptibility. The aim of this study was to test for gene–gene/gene-sex epistasis (interactions) in these known lupus susceptibility loci. Six single-nucleotide polymorphisms (SNPs) in MiR146a, IRF5, IKZF1, ETS1 and IL21 were genotyped by Sequenom MassArray system. A total of 1,825 subjects (858 SLE patients and 967 controls) were included in the final analysis. Epistasis was tested by additive model, multiplicative model and multifactor dimensionality reduction (MDR) method. Additive interaction analysis revealed interactions between IRF5 and IKZF1 (OR 2.26, 95% CI 1.48–3.44 [P = 1.21×104]). A similar tendency was also observed between IL21 and ETS1 by parametric methods. In addition, multiple high dimensional gene-gene or gene-sex interactions (three-and four-way) were identified by MDR analysis. Our study identified novel gene–gene/gene-sex interactions in lupus. Furthermore, these findings highlight sex, interferon pathway, and Th17/B cells as important contributors to the pathogenesis of SLE.

The dual nature of Ets-1: focus to the pathogenesis of systemic lupus erythematosus.

E26 transformation-specific-1 (Ets-1) belongs to the Ets family of transcription factors which share a common 85-amino-acid DNA-binding domain. Ets-1 is essential to regulation of the immune system including immune cell proliferation and differentiation. Past data demonstrated Ets-1 play a role in negative regulation of Th17 cells and B cells differentiation. Recently, association of genetic variation in Ets-1 with susceptibility to systemic lupus erythematosus (SLE) have been independently identified by two Genome-wide association studies (GWAS), and decreased Ets-1mRNA level in peripheral blood mononuclear cells (PBMCs) of SLE patients has been reported. All these findings suggest that the transcription factor is broadly linked to the pathogenesis of this disease. However, aberrant control of other immune cells and effector molecules illuminated the complexities of Ets-1 biology. In this review article, we will focus on the dual nature of Ets-1 and discuss its regulatory capability. Hopefully the information obtained will lead to a better understanding of the pathogenesis and development of novel therapeutic strategies for SLE.

Expression profiles of Th17 pathway related genes in human systemic lupus erythematosus.

Recently, evidence is emerging that inappropriate regulation of type 17 T helper cells (Th17) plays a fundamental role in the development of many autoimmune diseases including systemic lupus erythematosus (SLE). However, the role of Th17-related cytokines in SLE remains elusive. To further investigate the role and imbalance of Th17-related cytokines in the pathogenesis of SLE. A Quantitative RT-PCR Array (Human Th17 for Autoimmunity & Inflammation PCR Array) analyses were performed to study Th17-related genes expression in peripheral white blood cells of 25 new-onset patients with SLE and 15 healthy subjects. When gene expression for SLE patients was compared to the mean of normal controls, among the 84 target genes related to Th17 pathway, 7 (CXCL1, ICAM1, IL10, IL5, IL8, ISG20, JAK2,) were upregulated and 6 (CD28, CD40LG, S1PR1, IL17RE, IL23R, RORC) downregulated. However, comparisons of mRNA expression of Th17 related cytokines between lupus nephritis (LN) patients and SLE patients without nephritis (SLE non LN) showed no significant difference. In conclusion, SLE patients and normal controls showed different expression of a few genes in Th17 pathway, indicating that the pathway may be involved in the pathogenesis of SLE.