Hypomethylation of miR-17-92 cluster in lupus T cells and no significant role for genetic factors in the lupus-associated DNA methylation signature

The Complex Role of Gut Microbiota in Systemic Lupus Erythematosus and Lupus Nephritis: From Pathogenetic Factor to Therapeutic Target

The role of gut microbiota (GM) and intestinal dysbiosis in triggering the onset and/or modulating the severity and progression of lupus nephritis (LN) has been the object of intense research over the last few years. Some alterations at the phyla level, such as the abundance of Proteobacteria and reduction in Firmicutes/Bacteroidetes (F/B) ratio and in α-diversity have been consistently reported in systemic lupus erythematosus (SLE), whereas a more specific role has been ascribed to some species (Bacteroides thetaiotaomicron and Ruminococcus gnavus) in LN. Underlying mechanisms include microbial translocation through a "leaky gut" and subsequent molecular mimicry, immune dysregulation (alteration of IFNγ levels and of balance between Treg and Th17 subsets), and epigenetic interactions. Levels of bacterial metabolites, such as butyrate and other short-chain fatty acids (SCFAs), appear to play a key role in modulating LN. Beyond bacterial components of GM, virome and mycobiome are also increasingly recognized as important players in the modulation of an immune response. On the other hand, microbiota-based therapy appears promising and includes diet, prebiotics, probiotics, symbiotics, and fecal microbiota transplantation (FMT). The modulation of microbiota could correct critical alterations, such as F/B ratio and Treg/Th17 imbalance, and blunt production of autoantibodies and renal damage. Despite current limits, GM is emerging as a powerful environmental factor that could be harnessed to interfere with key mechanisms leading to SLE, preventing flares and organ damage, including LN. The aim of this review is to provide a state-of-the-art analysis of the role of GM in triggering and modulating SLE and LN on the one hand, while exploring possible therapeutic manipulation of GM to control the disease on the other hand.

The multiple roles of interferon regulatory factor family in health and disease

Interferon Regulatory Factors (IRFs), a family of transcription factors, profoundly influence the immune system, impacting both physiological and pathological processes. This review explores the diverse functions of nine mammalian IRF members, each featuring conserved domains essential for interactions with other transcription factors and cofactors. These interactions allow IRFs to modulate a broad spectrum of physiological processes, encompassing host defense, immune response, and cell development. Conversely, their pivotal role in immune regulation implicates them in the pathophysiology of various diseases, such as infectious diseases, autoimmune disorders, metabolic diseases, and cancers. In this context, IRFs display a dichotomous nature, functioning as both tumor suppressors and promoters, contingent upon the specific disease milieu. Post-translational modifications of IRFs, including phosphorylation and ubiquitination, play a crucial role in modulating their function, stability, and activation. As prospective biomarkers and therapeutic targets, IRFs present promising opportunities for disease intervention. Further research is needed to elucidate the precise mechanisms governing IRF regulation, potentially pioneering innovative therapeutic strategies, particularly in cancer treatment, where the equilibrium of IRF activities is of paramount importance.

Methyl-donor supplementation in women with systemic lupus erythematosus with different nutritional status: the protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

DNA hypomethylation in patients with systemic lupus erythematosus (SLE) has been recently documented in the literature. Low levels of DNA methylation have been observed globally and in genes associated with immune and inflammatory pathways in SLE's CD4+T lymphocytes. Given that certain micronutrients can either donate methyl groups within one-carbon metabolism pathways or serve as cofactors for enzymes involved in the DNA methylation process, this randomised, double-blind, placebo-controlled trial aims to investigate whether a 3-month supplementation of folic acid and vitamin B12 will modulate the DNA methylation profile in subcutaneous adipose tissue (primary outcome) of women with SLE and normal weight or excess body weight. As secondary objectives, we will assess gene expression, telomere length and phenotypic characteristics (ie, clinical parameters, body weight and composition, abdominal circumference, food intake and disordered eating attitude, physical activity, lipid profile, serum concentrations of leptin, adiponectin, and cytokines).

METHODS AND ANALYSIS

Patients will be classified according to their nutritional status by body mass index in normal weight or excess body weight. Subsequently, patients in each group will be randomly assigned to either a placebo or an intervention group (folic acid (400 mcg) and vitamin B12 (2000 mcg) supplementation). Endpoint evaluations will be conducted using both intention-to-treat and per-protocol analyses. This study has the potential to design new personalised nutritional approaches as adjunctive therapy for patients with SLE.

ETHICS AND DISSEMINATION

This study has been reviewed and approved by the Ethical Committee from Clinical Hospital of the School of Medicine of the University of Sao Paulo, Brazil (CAAE.: 47317521.8.0000.0068).

TRIAL REGISTRATION NUMBER

NCT05097365 (first version).

Methylation of T and B Lymphocytes in Autoimmune Rheumatic Diseases

The role of abnormal epigenetic modifications, particularly DNA methylation, in the pathogenesis of autoimmune rheumatic diseases (ARDs) has garnered increasing attention. Lymphocyte dysfunction is a significant contributor to the pathogenesis of ARDs. Methylation is crucial for maintaining normal immune system function, and aberrant methylation can hinder lymphocyte differentiation, resulting in functional abnormalities that disrupt immune tolerance, leading to the excessive expression of inflammatory cytokines, thereby exacerbating the onset and progression of ARDs. Recent studies suggest that methylation-related factors have the potential to serve as biomarkers for monitoring the activity of ARDs. This review summarizes the current state of research on the impact of DNA and RNA methylation on the development, differentiation, and function of T and B cells and examines the progress of these epigenetic modifications in studies of six specific ARDs: systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, systemic sclerosis, juvenile idiopathic arthritis, and ankylosing spondylitis. Additionally, we propose that exploring the interplay between RNA methylation and DNA methylation may represent a novel direction for understanding the pathogenesis of ARDs and developing novel treatment strategies.

Childhood-onset systemic lupus erythematosus: characteristics and the prospect of glucocorticoid pulse therapy

Childhood-onset systemic lupus erythematosus (cSLE) is an autoimmune disease that results in significant damage and often needs more aggressive treatment. Compared to adult-onset SLE, cSLE has a stronger genetic background and more prevalent elevated type I Interferon expression. The management of cSLE is more challenging because the disease itself and treatment can affect physical, psychological and emotional growth and development. High dose oral glucocorticoid (GC) has become the rule for treating moderate to severe cSLE activity. However, GC-related side effects and potential toxicities are problems that cannot be ignored. Recent studies have suggested that GC pulse therapy can achieve disease remission rapidly and reduce GC-related side effects with a reduction in oral prednisone doses. This article reviews characteristics, including pathogenesis and manifestations of cSLE, and summarized the existing evidence on GC therapy, especially on GC pulse therapy in cSLE, followed by our proposal for GC therapy according to the clinical effects and pathogenesis.

Pathogenesis of systemic lupus erythematosus: risks, mechanisms and therapeutic targets

Research elucidating the pathogenesis of systemic lupus erythematosus (SLE) has defined two critical families of mediators, type I interferon (IFN-I) and autoantibodies targeting nucleic acids and nucleic acid-binding proteins, as fundamental contributors to the disease. On the fertile background of significant genetic risk, a triggering stimulus, perhaps microbial, induces IFN-I, autoantibody production or most likely both. When innate and adaptive immune system cells are engaged and collaborate in the autoimmune response, clinical SLE can develop. This review describes recent data from genetic analyses of patients with SLE, along with current studies of innate and adaptive immune function that contribute to sustained IFN-I pathway activation, immune activation and autoantibody production, generation of inflammatory mediators and tissue damage. The goal of these studies is to understand disease mechanisms, identify therapeutic targets and stimulate development of therapeutics that can achieve improved outcomes for patients.

Epigenome-wide association study of serum folate in maternal peripheral blood leukocytes

Aim: To perform an epigenome-wide association study (EWAS) of serum folate in maternal blood. Methods: Cross-ancestry (Europeans = 302, South Asians = 161) and ancestry-specific EWAS in the EPIPREG cohort were performed, followed by methyl quantitative trait loci analysis and association with cardiometabolic phenotypes. Replication was attempted using maternal folate intake and blood methylation data from the MoBa study and verified if the findings were significant in a previous EWAS of maternal serum folate in cord blood. Results & conclusion: cg19888088 (cross-ancestry) in EBF3, cg01952260 (Europeans) and cg07077240 (South Asians) in HERC3 were associated with serum folate. cg19888088 and cg01952260 were associated with diastolic blood pressure. cg07077240 was associated with variants in CASC15. The findings were not replicated and were not significant in cord blood.