Immunopathogenesis of systemic lupus erythematosus and rheumatoid arthritis: the role of aberrant expression of non‐coding RNAs in T cells

Non‐coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non‐coding RNAs (lncRNAs), are RNA molecules that do not translate into protein. Both miRNAs and lncRNAs are known to regulate gene expression and to play an essential role in T cell differentiation and function. Both systemic lupus erythematosus (SLE), a prototypic systemic autoimmune disease, and rheumatoid arthritis (RA), a representative disease of inflammatory arthritis, are characterized by a complex dysfunction in the innate and adaptive immunity. T cells play a central role in cell‐mediated immune response and multiple defects in T cells from patients with SLE and RA have been observed. Abnormality in T cell signalling, cytokine and chemokine production, T cell activation and apoptosis, T cell differentiation and DNA methylation that are associated closely with the aberrant expression of a number of miRNAs and lncRNAs have been implicated in the immunopathogenesis of SLE and RA. This review aims to provide an overview of the current state of research on the abnormal expression of miRNAs and lncRNAs in T cells and their roles in the immunopathogenesis of SLE and RA. In addition, by comparing the differences in aberrant expression of miRNAs and lncRNAs in T cells between patients with SLE and RA, controversial areas are highlighted that warrant further investigation.     

Atherosclerosis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease that has a late mortality phase owing mainly to cardiovascular manifestations. Atherosclerosis itself is characterized by inflammatory components, fulfilling the criteria of Witebsky and Rose for an autoimmune disease. SLE patients have increased risk for cardiovascular events, and these are the result of both atherosclerosis and thromboembolic events. Risk factors for atherosclerosis in SLE include “traditional” risk factors (mainly the Framingham risk factors), as well as disease-related factors including disease duration, steroid therapy, and renal disease, and inflammatory mechanisms that specifically contribute to enhanced atherosclerosis in SLE. These include specific antibodies to β2GPI; anticardiolipin antibodies; anti-oxidized low-density lipoprotein; and antibodies to heat shock proteins, complement activation, impaired ability to activate TGF-β1, and elevated levels of CRP. These findings stress the importance of surveillance and preventive strategies to control atherosclerosis in SLE.     

炎性细胞因子在系统性红斑狼疮中的作用

系统性红斑狼疮是一个全身性自身免疫病，常伴多器官受累，许多炎性细胞因子参与了系统性红斑狼疮的发病与发展，该病的活动性及器官损伤程度与不同的细胞因子相关。     

New therapies for systemic lupus erythematosus

In the past 40 years, prognosis for patients with systemic lupus erythematosus (SLE) has improved, with 10-year survival now approximately 90%. This is due probably to a combination of earlier disease diagnosis and diagnosis of milder disease, due in part to availability of multiple serological tests for SLE, use of steroids and other immunosuppressive agents, and availability of renal dialysis and transplantation. Despite this, however, the potential for significant morbidity and mortality remains in the group of patients with partially responsive or treatment resistant disease. More recently, advancements in the understanding of molecular mechanisms involved in the pathogenesis of SLE have translated to the development of novel therapies, offering possible alternatives to this patient cohort. Discussion of these pharmacological options and ongoing research forms the basis of this review.     

Haem oxygenase 1 expression is altered in monocytes from patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple functional alterations affecting immune cells, such as B cells, T cells, dendritic cells (DCs) and monocytes. During SLE, the immunogenicity of monocytes and DCs is significantly up-regulated, promoting the activation of self-reactive T cells. Accordingly, it is important to understand the contribution of these cells to the pathogenesis of SLE and the mechanisms responsible for their altered functionality during disease. One of the key enzymes that control monocyte and DC function is haem oxygenase-1 (HO-1), which catalyses the degradation of the haem group into biliverdin, carbon monoxide and free iron. These products possess immunosuppressive and anti-inflammatory capacities. The main goal of this work was to determine HO-1 expression in monocytes and DCs from patients with SLE and healthy controls. Hence, peripheral blood mononuclear cells were obtained from 43 patients with SLE and 30 healthy controls. CD14(+) monocytes and CD4(+) T cells were sorted by FACS and HO-1 expression was measured by RT-PCR. In addition, HO-1 protein expression was determined by FACS. HO-1 levels in monocytes were significantly reduced in patients with SLE compared with healthy controls. These results were confirmed by flow cytometry. No differences were observed in other cell types, such as DCs or CD4(+) T cells, although decreased MHC-II levels were observed in DCs from patients with SLE. In conclusion, we found a significant decrease in HO-1 expression, specifically in monocytes from patients with SLE, suggesting that an imbalance of monocyte function could be partly the result of a decrease in HO-1 expression.     

New insights into the progression from cutaneous lupus to systemic lupus erythematosus

ABSTRACT

Introduction

Between 5 and 25% of patients with cutaneous lupus erythematosus (CLE) can progress to systemic lupus erythematosus (SLE) during the course of the disease. There is no clear predictive guideline for the progression of CLE to SLE.     

Differential serum cytokine profile in patients with systemic lupus erythematosus and posterior reversible encephalopathy syndrome

Systemic lupus erythematosus (SLE) patients are susceptible to the development of posterior reversible encephalopathy syndrome (PRES). The main theory concerning the physiopathology of PRES suggests that there is brain–blood barrier damage, which is associated with endothelial dysfunction, and characterized by vasogenic oedema. However, current evidence regarding its physiopathogenic mechanisms is quite scant. The aim of this study was to analyse the expression of different serum cytokines, as well as vascular endothelial growth factor (VEGF) and soluble CD40 ligand (sCD40L), in patients with PRES/systemic lupus erythematosus (SLE) and to compare them with levels in SLE patients without PRES and in healthy controls. We performed a transversal study in a tertiary care centre in México City. We included 32 subjects (healthy controls, n = 6; remission SLE, n = 6; active SLE, n = 6 and PRES/SLE patients, n = 14). PRES was defined as reversible neurological manifestations (seizures, visual abnormalities, acute confusional state), associated with compatible changes by magnetic resonance imaging (MRI). Serum samples were obtained during the first 36 h after the PRES episode and were analysed by cytometric bead array, Luminex multiplex assay or enzyme‐linked immunosorbent assay (ELISA). Interleukin (IL)‐6 and IL‐10 levels were significantly higher in PRES/SLE patients (P = 0·013 and 0·025, respectively) when compared to the other groups. Furthermore, IL‐6 and IL‐10 levels displayed a positive correlation (r = 0·686, P = 0·007). There were no differences among groups regarding other cytokines, sCD40L or VEGF levels. A differential serum cytokine profile was found in PRES/SLE patients, with increased IL‐6 and IL‐10 levels. Our findings, which are similar to those described in other neurological manifestations of SLE, support the fact that PRES should be considered among the SLE‐associated neuropsychiatric syndromes.     

An antibody profile of systemic lupus erythematosus detected by antigen microarray

Patients with systemic lupus erythematosus (SLE) produce antibodies to many different self‐antigens. Here, we investigated antibodies in SLE sera using an antigen microarray containing many hundreds of antigens, mostly self‐antigens. The aim was to detect sets of antibody reactivities characteristic of SLE patients in each of various clinical states – SLE patients with acute lupus nephritis, SLE patients in renal remission, and SLE patients who had never had renal involvement. The analysis produced two novel findings: (i) an SLE antibody profile persists independently of disease activity and despite long‐term clinical remission, and (ii) this SLE antibody profile includes increases in four specific immunoglobulin G (IgG) reactivities to double‐stranded DNA (dsDNA), single‐stranded DNA (ssDNA), Epstein–Barr virus (EBV) and hyaluronic acid; the profile also includes decreases in specific IgM reactivities to myeloperoxidase (MPO), CD99, collagen III, insulin‐like growth factor binding protein 1 (IGFBP1) and cardiolipin. The reactivities together showed high sensitivity (> 93%) and high specificity for SLE (> 88%). A healthy control subject who had the SLE antibody profile was later found to develop clinical SLE. The present study did not detect antibody reactivities that differentiated among the various subgroups of SLE subjects with statistical significance. Thus, SLE is characterized by an enduring antibody profile irrespective of clinical state. The association of SLE with decreased IgM natural autoantibodies suggests that these autoantibodies might enhance resistance to SLE.     

Endogenous retroviruses in systemic lupus erythematosus: candidate lupus viruses

Although the etiology of systemic lupus erythematosus (SLE) remains unclear, there is substantial circumstantial evidence that the development of SLE is dependent on environmental, genetic, and retroviral factors. SLE patients produce high titer antibodies to various retroviral proteins, including Gag, Env, and Nef of HIV and HTLV, in the absence of overt retroviral infection. We review the factors linking HERVs to SLE and consider the various processes utilized by endogenous retroviruses in the etiopathogenesis of SLE. In particular, we consider the role of HTLV-1-related endogenous sequence (HRES-1) in SLE. We propose that molecular mimicry between HRES-1 and the small ribonucleoprotein complex initiates the production of autoantibodies, leading to immune complex formation, complement fixation, and pathological tissue deposition.     

抗核小体抗体与儿童系统型红斑狼疮的相关性

目的探讨抗核小体抗体（AnuA）在诊断儿童系统型红斑狼疮（SLE）中的敏感性和特异性，了解AnuA与儿童SLE临床特征、疾病活动性的相关性。方法用Hep-2细胞提取核小体。用酶联免疫吸附方法（ELISA）测定血清中的AnuA，分析AnuA和临床表现的相关性。结果52例SLE中18例AnuA阳性。27例疾病对照组中1例AnuA阳性，30例正常对照组AnuA均为阴性。AnuA在儿童SLE中的敏感性为35％，特异性为96％。AnuA阳性组SLE患儿100％有中枢神经系统损害，AnuA阴性组为47％（x^2=14．57，P〈0．05）。AnuA阳性组SLE患儿100％有肾脏损害，AnuA阴性组为5l％（x^2=13．31，P〈0．05）。AnuA阳性和AnuA阴性的SLE患儿SLEDAI评分高于10分者分别为100％和71％（x^2=6．56，P〈0．05）。结论AnuA对儿童SLE的诊断具有较高的特异性，有助于抗dsDNA抗体、抗心磷脂抗体阴性的儿童SLE的诊断。     

HLA-G genotype and HLA-G expression in systemic lupus erythematosus: HLA-G as a putative susceptibility gene in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease mainly mediated by the deposit of immune complexes and defects in T lymphocytes and antigen-presenting cells along with a high production of T-helper 2 cytokines. A tolerance-inducible function of nonclassical class Ib human leukocyte antigen (HLA)-G molecule in innate and adaptive cellular responses has been reported, suggesting a role in inflammatory diseases. A 14 bp sequence insertion/deletion polymorphism (rs16375) in the 3'-untranslated region of the HLA-G gene has been associated to the stability of HLA-G messenger RNA. The insertion of the 14 bp sequence seems to be associated with lower levels of soluble HLA-G (sHLA-G). The aim of this study was to evaluate the possible association of the presence of the 14 bp sequence (+14 bp) with SLE. We have HLA-G genotyped 200 SLE patients and 451 healthy control subjects (HS; Italian) and analyzed the plasma levels of sHLA-G and interleukin-10 (IL-10) in a subset of SLE patients and healthy subjects (Italian and Danish). A significant increase of the +14 bp HLA-G allele was detected in the Italian SLE patients compared with HS [P = 0.003, OR 1.44 (95% CI 1.13-1.82)]. A significant increased frequency of HLA-G +14/+14 bp and a decreased frequency of HLA-G -14/-14 bp were observed in SLE patients. There median concentration of sHLA-G was significantly lower in the plasma of SLE patients compared with that in the plasma of healthy controls (P < 0.0001). Furthermore, the results confirmed higher concentrations of IL-10-positive plasma in SLE patients. These results support a potential role for HLA-G in the susceptibility of SLE.     

系统性红斑狼疮遗传学研究进展

系统性红斑狼疮（systemic lupus erythematosus,SLE)通常被认为是自身免疫疾病的原型，遗传因素在疾病的发生中起重要作用。对狼疮鼠模型的研究已发现约30个基因位点与疾病产生有关，不同位点影响发病的不同环节。人类基因组研究则50个左右基因位点与SLE有关，其中1q23-24,1q41-42,2q37,4p16-15.2,6p21-11及16q13为6个显著相关区域，对特定患者，多个位点不同基因的组合可导致疾病表型的多样性。近期对候选基因的研究进一步证实，遗传因素在决定疾病易感性及临床表型时起作用，不同群体中所涉及的基因或其表达强度均有差异。     

Gene expression profiles of systemic lupus erythematosus and rheumatoid arthritis

Gene expression profiling using microarray technology is being employed to define specific molecular mediators and pathways involved in immunobiology, to understand the intricate interplay of genes participating in the pathogenesis, and to develop biomarkers of disease activity in both systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). This review summarizes the latest information on the pathogenesis of SLE and RA and describes the utilization of microarray technology in these systemic autoimmune diseases.     

Infectious processes and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease of unknown etiology, although genetic and environmental factors appear to contribute to its pathogenesis. Specifically, infectious processes are associated with SLE onset and exacerbation. However, we are far from a complete understanding of the interactions between infectious agents and the host, explaining the interest in gathering updated scientific information on this topic. According to the literature, the pathogens most frequently associated with SLE are viruses, notably human endogenous retroviruses, Epstein–Barr virus, parvovirus B19, cytomegalovirus and human immunodeficiency virus type 1, alongside certain bacterial components that can also trigger activation of the immune system. The mechanisms underlying autoreactivity remain unclear but various explanations have been proposed, including immunological changes responsible for infectious processes or molecular mimicry between host structures and those of infectious agents.     

系统性红斑狼疮合并胸腺瘤的临床特点分析

目的探讨系统性红斑狼疮(SLE)合并胸腺瘤的的临床特点。方法回顾性分析1984年至2015年北京协和医院收治的SLE合并胸腺瘤患者的临床资料,分析临床特点、实验室检查、治疗方式和预后,并与同期国内外报道的SLE合并胸腺瘤的病例资料进行比较。结果 SLE合并胸腺瘤住院患者共11例,占SLE患者的1.55‰,占胸腺瘤患者的1.07%。女性10例,男性1例。SLE平均起病年龄25.5岁,平均确诊年龄26.4岁,胸腺瘤的平均确诊年龄28.5岁。SLE进展至胸腺瘤的平均病程为2.1年。确诊胸腺瘤时SLEDAI均值为3.6。5例患者行胸腺切除术,1例患者放疗。4例胸腺瘤标本可用于WHO分型,A型2例,AB型1例,C型1例。8例患者随访3~92月,6例SLE稳定,1例SLE活动,1例死于肿瘤转移。与国内外文献报道资料相比,本研究中的SLE合并胸腺瘤患者年龄偏小,发现胸腺瘤后的手术切除率偏低。结论 SLE合并胸腺瘤并非偶然现象,胸腺瘤症状隐匿,可能参与SLE发病。胸腺切除可能有助于SLE的临床缓解,应引起临床医师的重视。     

Epigenetic dysregulation in systemic lupus erythematosus

Abstract

Systemic lupus erythematosus (SLE) is a prototypical systemic autoimmune disease that affects multiple organs and is characterized by episodic flares and elevated morbidity. The etiology of SLE is only partly known. In this context, recent attention has been paid to the importance of environmentally induced epigenetic modifications as significant contributors to the disease pathogenesis in genetically predisposed individuals. Here we review what is currently known on the role of epigenetics in SLE, and the investigations aimed at possibly targeting epigenetic mechanisms and/or related biomarkers to improve the monitoring, management and, ultimately, the prognosis of SLE.     

Utilizing registries in systemic lupus erythematosus clinical research

Systemic lupus erythematosus is a complex and heterogeneous autoimmune disease with a relatively low incidence. Clinical research in this disease at individual centers is complicated by the difficulty of accruing enough patient numbers. In this context, the development of cohorts and multi-institutional registries during the last decades has allowed an increase in knowledge regarding the clinical course and management of this disease. This article aims to describe the main study designs linked to lupus registries and to give an overview of the main international registries and cohorts, as well as their principal achievements in the context of this complex entity.     

Immunosuppressive therapy modulates T lymphocyte gene expression in patients with systemic lupus erythematosus

To evaluate the T-cell large-scale differential gene expression in systemic lupus erythematosus (SLE) patients presenting with glomerulonephritis we studied SLE patients before and after immunosuppressive treatment. Large-scale gene expression of peripheral blood mononuclear T cells was evaluated using cDNA microarray nylon membranes containing 5184 cDNAs. Data were analysed using the SAM and Cluster and Treeview software. When untreated patients were compared to healthy individuals, 38 genes, most of them located on chromosomes 1, 3, 6, 17 and 19, were repressed, and when untreated patients were compared to treated ones, 154 genes, located on chromosomes 1, 6, 7, 12 and 17, were induced. In terms of biological function of coded proteins, the differentially expressed genes were associated with apoptosis, cell cycle, chromosomal scaffold, cytokine/chemokine, DNA repair/replication, Golgi/mitochondrial proteins, mRNA processing, signalling molecules and tumour suppressors. Two autoantigen genes related to RNA splicing (small nuclear riboprotein 70,000 MW-U1 SNR, and splicing factor 3a, 60,000 MW), and the tetranectin-plasminogen-binding protein were repressed. The Fc fragment of immunoglobulin G low affinity IIb, apoptotic protease activating factor-1, two subunits of cytochrome c, caspase 8, complement C5a, HLA-DRA, HLA-DQB1, transforming growth factor-beta receptor II, small nuclear ribonucleoprotein polypeptide N (Sm protein N) genes, heterogeneous nuclear riboprotein-C, and argininosuccinate lyase genes, among others, were induced. A total of 10 genes were repressed in untreated patients and induced in treated ones, among them tumour necrosis factor (ligand) superfamily member 9, tumour protein p53, mannosidase alpha class IA, and CD22. Although some of these differentially expressed genes are typically expressed in B cells, CD22 and CD32 have also been reported in T cells and may provide regulatory signals to B cells. Assessment of differential gene expression may provide hybridization signatures that may identify susceptibility, diagnostic and prognostic markers of SLE.     

Characterization of anti-endothelial cell antibodies in systemic lupus erythematosus (SLE).

IgG anti-endothelial antibodies (AEA), as measured by ELISA or immunoblotting technique could be detected in serum samples of 56 out of 64 patients with SLE (88%) and mainly occurred in monomeric form. AEA were not cell specific, because the binding reactivity was absorbed partially by both fibroblasts and peripheral blood mononuclear cells. No correlation was found between the presence of AEA and anti-nuclear antibodies. Immunoblotting revealed reactivity of AEA against endothelial antigens ranging in size from 15 to 200 kD. AEA titres were significantly higher in patients with joint or skin abnormalities, compared with patients without these abnormalities. A significant correlation was found between nephritis in SLE and the presence of AEA reactivity against endothelial membrane antigens of 38, 41 and 150 kD. These data show that the pattern of AEA reactivity in serum of SLE patients is heterogeneous, and suggest that AEA against a limited number of antigens may be involved in the pathogenesis of nephritis in SLE.