X-linked genes exhibit miR6891-5p-regulated skewing in Sjögren's syndrome

Sjogren's syndrome: Everything you always wanted to know about genetic and epigenetic factors

Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease characterized by a wide spectrum of glandular and extra-glandular features. Genetic and epigenetic factors play an important role in the disease susceptibility and phenotype. There are a multitude of genes that have been identified as implicated in the pathogenesis of pSS, both in HLA and extra-HLA regions with a strong contribution given by genes in interferon signalling pathways. Among the HLA alleles, the most consistent associations have been found with DR2 and DR3 alleles at the DRB1 locus. Moreover, several gene variants outside the MHC locus are in genes involved in NF-κB signalling, B- and T-cell function and methylation processes possibly responsible for lymphomagenesis. There is still a lack of knowledge on precise genetic patterns and prediction models of diseases, and data on pharmacogenetics is scarce. A comprehensive summary of the common genetic factors and an extensive analysis of novel epigenetic aspects is provided, together with a view on the relationships between novel therapeutic agents for pSS and genetic targets in signalling pathways, aiming at improving tailored treatment strategies in the view of a more personalized medicine.

Epigenetic Modulations of Non-Coding RNAs: A Novel Therapeutic Perspective in Sjӧgren's Syndrome

Sjögren's syndrome (SS) is an autoimmune disease that can be classified as an epithelitis based on the immune-mediated attack directed specifically at epithelial cells. SS predominantly affects women, is characterized by the production of highly specific circulating autoantibodies, and the major targets are the salivary and lachrymal glands. Although a genetic predisposition has been amply demonstrated for SS, the etiology remains unclear. The recent integration of epigenetic data relating to autoimmune diseases opens new therapeutic perspectives based on a better understanding of the molecular processes implicated. In the autoimmune field, non-coding RNA molecules (nc-RNA), which regulate gene expression by binding to mRNAs and could have a therapeutic value, have aroused great interest. The focus of this review is to summarize the biological functions of nc-RNAs in the pathogenesis of SS and decode molecular pathways implicated in the disease, in order to identify new therapeutic strategies.

Long Non-Coding RNAs in Sjögren's Disease

Sjögren's disease (SjD) is a heterogeneous autoimmune disease characterized by severe dryness of mucosal surfaces, particularly the mouth and eyes; fatigue; and chronic pain. Chronic inflammation of the salivary and lacrimal glands, auto-antibody formation, and extra-glandular manifestations occur in subsets of patients with SjD. An aberrant expression of long, non-coding RNAs (lncRNAs) has been described in many autoimmune diseases, including SjD. Here, we review the current literature on lncRNAs in SjD and their role in regulating X chromosome inactivation, immune modulatory functions, and their potential as biomarkers.

Advances in mesenchymal stem cell-derived extracellular vesicles therapy for Sjogren's syndrome-related dry eye disease

Sjogren's syndrome (SS) is a chronic autoimmune disorder that affects exocrine glands, particularly lacrimal glands, leading to dry eye disease (DED). DED is a common ocular surface disease that affects millions of people worldwide, causing discomfort, visual impairment, and even blindness in severe cases. However, there is no definitive cure for DED, and existing treatments primarily relieve symptoms. Consequently, there is an urgent need for innovative therapeutic strategies based on the pathophysiology of DED. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic tool for various autoimmune disorders, including SS-related DED (SS-DED). A particularly intriguing facet of MSCs is their ability to produce extracellular vesicles (EVs), which contain various bioactive components such as proteins, lipids, and nucleic acids. These molecules play a key role in facilitating communication between cells and modulating a wide range of biological processes. Importantly, MSC-derived EVs (MSC-EVs) have therapeutic properties similar to those of their parent cells, including immunomodulatory, anti-inflammatory, and regenerative properties. In addition, MSC-EVs offer several notable advantages over intact MSCs, including lower immunogenicity, reduced risk of tumorigenicity, and greater convenience in terms of storage and transport. In this review, we elucidate the underlying mechanisms of SS-DED and discuss the relevant mechanisms and targets of MSC-EVs in treating SS-DED. In addition, we comprehensively review the broader landscape of EV application in autoimmune and corneal diseases. This review focuses on the efficacy of MSC-EVs in treating SS-DED, a field of study that holds considerable appeal due to its multifaceted regulation of immune responses and regenerative functions.

Universal or Personalized Mesenchymal Stem Cell Therapies: Impact of Age, Sex, and Biological Source

Mesenchymal stem/stromal cells (MSCs) hold great promise for the treatment of autoimmune conditions given their immunomodulatory properties. Based on the low immunogenicity of MSCs, it is tempting to consider the expansion of MSCs from a "universal donor" in culture prior to their allogeneic applications for immediate care. This raises the critical question of the criteria we should use to select the best "universal donor". It is also imperative we compare the "universal" approach with a "personalized" one for clinical value. In addition to the call for MHC-matching, recent studies suggest that factors including age, sex, and biological sources of MSCs can have significant impact on therapy outcome. Here, we will review findings from these studies, which shed light on the variables that can guide the important choice of "universal" or "personalized" MSC therapy for autoimmune diseases.

Abnormal Epigenetic Regulations in the Immunocytes of Sjögren's Syndrome Patients and Therapeutic Potentials

Sjögren's syndrome (SjS), characterized by keratoconjunctivitis sicca and dry mouth, is a common autoimmune disease, especially in middle-aged women. The immunopathogenesis of SjS is caused by the sequential infiltration of T and B cells into exocrine glands, including salivary and lacrimal glands. Effector cytokines produced by these immunocytes, such as interferons (IFNs), IL-17, IL-22, IL-21, IL-4, TNF-α, BAFF and APRIL, play critical roles in promoting autoimmune responses and inducing tissue damages. Epigenetic regulations, including DNA methylation, histone modification and non-coding RNAs, have recently been comprehensively studied during the activation of various immunocytes. The deficiency of key epigenetic enzymes usually leads to aberrant immune activation. Epigenetic modifications in T and B cells are usually found to be altered during the immunopathogenesis of SjS, and they are closely correlated with autoimmune responses. In particular, the important role of methylation in activating IFN pathways during SjS progression has been revealed. Thus, according to the involvement of epigenetic regulations in SjS, target therapies to reverse the altered epigenetic modifications in auto-responsive T and B cells are worthy of being considered as a potential therapeutic strategy for SjS.