The role of dietary sodium in autoimmune diseases: The salty truth

Interactions between microbiota, diet/nutrients and immune/inflammatory response in rheumatic diseases: focus on rheumatoid arthritis

Rheumatic and musculoskeletal diseases (RMDs) are chronic systemic immune/inflammatory conditions characterized by the interaction between gene predisposition, autoimmunity and environmental factors. A growing scientific interest has focused on the role of diet in RMDs, suggesting its significant contribution to the pathogenesis and prognosis of these diseases. It is now clear that diet can directly modulate the immune response by providing a wide range of nutrients, which interfere with multiple pathways at both the gastro-intestinal and systemic level. Moreover, diet critically shapes the human gut microbiota, which is recognized to have a central role in the modulation of the immune response and in RMD pathogenesis. We hereby provide an in-depth analysis on the role of the microbiota in RMDs and on nutritional intervention as an integral part of a multidisciplinary approach. Particular attention will be given to the Mediterranean diet, as the only diet proven to support substantial benefits in RMD management.

Roles of circular RNAs in immune regulation and autoimmune diseases

Circular RNAs (circRNAs), as a novel class of endogenously expressed non-coding RNAs (ncRNAs), have a high stability and often present tissue-specific expression and evolutionary conservation. Emerging evidence has suggested that circRNAs play an essential role in complex human pathologies. Notably, circRNAs, important gene modulators in the immune system, are strongly associated with the occurrence and development of autoimmune diseases. Here, we focus on the roles of circRNAs in immune cells and immune regulation, highlighting their potential as biomarkers and biological functions in autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), primary biliary cholangitis (PBC), and psoriasis, aiming at providing new insights into the diagnosis and therapy of these diseases.

Challenges in the treatment of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic inflammatory disease characterized by a heterogeneous clinical response to the different treatments. Some patients are difficult to treat and do not reach the treatment targets as clinical remission or low disease activity. Known negative prognostic factors, such as the presence of auto-antiantibodies and joint erosion, the presence of a genetic profile, comorbidities and extra-articular manifestations, pregnancy or a pregnancy wish may concur to the treatment failure. In this review we aimed at identify difficult to treat RA patients and define the optimal therapeutic and environmental targets. Genetic markers of severity such as HLA-DRB1, TRAF1, PSORS1C1 and microRNA 146a are differently associated with joint damage; other gene polymorphisms seem to be associated with response to biologic disease modifying anti-rheumatic drugs (bDMARDs). The presence of comorbidities and/or extra-articular manifestations may influence the therapeutic choice; overweight and obese patients are less responsive to TNF inhibitors. In this context the patient profiling can improve the clinical outcome. Targeting different pathways, molecules, and cells involved in the pathogenesis of RA may in part justify the lack response of some patients. An overview of the future therapeutic targets, including bDMARDs (inhibitors of IL-6, GM-CSF, matrix metalloproteinases, chemokines) and targeted synthetic DMARDs (filgotinib, ABT-494, pefacitinib, decernotinib), and environmental targets is addressed. Environmental factors, such as diet and cigarette smoke, may influence susceptibility to autoimmune diseases and interfere with inflammatory pathways. Mediterranean diet, low salt intake, cocoa, curcumin, and physical activity seem to show beneficial effects, however studies of dose finding, safety and efficacy in RA need to be performed.

Role of NFAT5 in the Immune System and Pathogenesis of Autoimmune Diseases

The nuclear factor of activated T cells (NFAT5), also known as a tonicity-responsive enhancer-binding protein, was originally identified as a key transcription factor involved in maintaining cellular homeostasis against hypertonic and hyperosmotic environments. Although NFAT5 has been expressed and studied in various types of hyperosmolar tissues, evidence has emerged that NFAT5 plays a role in the development and activation of immune cells, especially T cells and macrophages. The immune-regulatory function of NFAT5 is achieved by inducing different target genes and different signaling pathways in both tonicity-dependent and -independent manners. Particularly in response to hyperosmotic stress, NFAT5 induces the generation of pathogenic T_H17 cells and pro-inflammatory macrophages, contributing to autoimmune and inflammatory diseases. Meanwhile, with tonicity-independent stimuli, including activation of the Toll-like receptors and inflammatory cytokines, NFAT5 also can be activated and promotes immune cell survival, proliferation, migration, and angiogenesis. Moreover, under isotonic conditions, NFAT5 has been implicated in the pathogenesis of a variety of inflammatory and autoimmune diseases including rheumatoid arthritis. This review describes the current knowledge of NFAT5, focusing on its immune-regulatory functions, and it highlights the importance of NFAT5 as a novel therapeutic target for chronic inflammatory diseases.

Review of Two Popular Eating Plans within the Multiple Sclerosis Community: Low Saturated Fat and Modified Paleolithic

The precise etiology of multiple sclerosis (MS) is unknown but epidemiologic evidence suggests this immune-mediated, neurodegenerative condition is the result of a complex interaction between genes and lifetime environmental exposures. Diet choices are modifiable environmental factors that may influence MS disease activity. Two diets promoted for MS, low saturated fat Swank and modified Paleolithic Wahls Elimination (WahlsElim), are currently being investigated for their effect on MS-related fatigue and quality of life (NCT02914964). Dr. Swank theorized restriction of saturated fat would reduce vascular dysfunction in the central nervous system (CNS). Dr. Wahls initially theorized that detailed guidance to increase intake of specific foodstuffs would facilitate increased intake of nutrients key to neuronal health (Wahls™ diet). Dr. Wahls further theorized restriction of lectins would reduce intestinal permeability and CNS inflammation (WahlsElim version). The purpose of this paper is to review the published research of the low saturated fat (Swank) and the modified Paleolithic (Wahls™) diets and the rationale for the structure of the Swank diet and low lectin version of the Wahls™ diet (WahlsElim) being investigated in the clinical trial.

Psychological stress and type 1 diabetes mellitus: what is the link?

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is a chronic disease characterized by the destruction of insulin-producing β-cells of the pancreas. The current paradigm in this disease's etiopathogenesis points toward the interplay of genetic and environmental factors. Among the environmental variables, dietary factors, intestinal microbiota, toxins, and psychological stress have been implicated in disease onset. Areas covered: This review aims to investigate the relationship between psychological stress and T1DM by presenting evidence from epidemiological studies, animal models, and to provide the mechanism involved in this association. The literature search was conducted through PubMed to identify studies that investigate the connection between stress and T1DM. Experimental designs, such as case-control, and retrospective and prospective cohorts studies, were included. Expert commentary: A wide array of evidence, ranging from epidemiological to animal models, points toward the role of psychological stressors in T1DM pathogenesis. Various mechanisms have been proposed, including the hypothalamic-pituitary-adrenal (HPA) axis, influence of the nervous system on immune cells, and insulin resistance. Further research could investigate the gene-stress interactions to evaluate the risk of T1DM development.