Decreased SUV39H1 at the promoter region leads to increased CREMα and accelerates autoimmune response in CD4+ T cells from patients with systemic lupus erythematosus

An updated review on abnormal epigenetic modifications in the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. The inconsistent prevalence of SLE between monozygotic twins suggests that environmental factors affect the occurrence of this disease. Abnormal epigenetic regulation is strongly associated with the pathogenesis of SLE. Epigenetic mechanisms may be involved in the development of lupus through DNA methylation, histone modification, noncoding RNAs, and other modifications. This review aims to show numerous studies as a treasure map to better understand the effects of aberrant epigenetic modification in the onset and development of SLE, which will benefit the current basic research and provide potential diagnostic biomarkers or therapeutic targets for SLE.

Redox-sensitive epigenetic activation of SUV39H1 contributes to liver ischemia-reperfusion injury

Liver ischemia-reperfusion (I/R) injury is a clinically relevant pathophysiological process that determines the effectiveness of life-saving liver transplantation, to which aberrant ROS accumulation plays a key role. In the present study we investigated the role of SUV39H1, a lysine methyltransferases, in this process focusing on regulatory mechanism and translational potential. We report that SUV39H1 expression was up-regulated in the liver tissues of mice subjected to ischemia-reperfusion and in hepatocytes exposed to hypoxia-reoxygenation (H/R) in a redox-sensitive manner. Mechanistically, coactivator associated arginine methyltransferases 1 (CARM1) mediated redox-sensitive Suv39h1 trans-activation by promoting histone H3R17 methylation. Consistently, pharmaceutical CARM1 inhibition attenuated liver I/R injury. In addition, global or hepatocyte conditional Suv39h1 KO mice were protected from liver I/R injury. RNA-seq revealed that aldehyde dehydrogenase 1 family 1a (Aldh1a1) as a novel target for SUV39H1. SUV39H1 directly bound to the Aldh1a1 promoter and repressed Aldh1a1 transcription in H/R-challenged hepatocytes. ALDH1A1 silencing abrogated the protective effects of SUV39H1 deficiency on H/R-inflicted injuries whereas ALDH1A1 over-expression mitigated liver I/R injury in mice. Importantly, administration of a small-molecule SUV39H1 inhibitor achieved similar hepatoprotective effects as SUV39H1 deletion. Finally, increased Suv39h1 expression and decreased Aldh1a1 expression were observed in liver I/R specimens in humans. In conclusion, our data uncover a regulatory role for SUV39H1 in liver I/R injury and serve as proof-of-concept that targeting the SUV39H1-ALDH1A1 axis might be considered as a reasonable approach for the intervention of liver I/R injury.

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.

Epigenetic mechanisms driving the pathogenesis of systemic lupus erythematosus, systemic sclerosis and dermatomyositis

Autoimmune connective tissue disorders, including systemic lupus erythematosus, systemic sclerosis (SSc) and dermatomyositis (DM), often manifest with debilitating cutaneous lesions and can result in systemic organ damage that may be life-threatening. Despite recent therapeutic advancements, many patients still experience low rates of sustained remission and significant treatment toxicity. While genetic predisposition plays a role in these connective tissue disorders, the relatively low concordance rates among monozygotic twins (ranging from approximately 4% for SSc to about 11%-50% for SLE) have prompted increased scrutiny of the epigenetic factors contributing to these diseases. In this review, we explore some seminal studies and key findings to provide a comprehensive understanding of how dysregulated epigenetic mechanisms can contribute to the development of SLE, SSc and DM.

Bioinformatics analysis of potential common pathogenic mechanisms for systemic lupus erythematosus and acute myocardial infarction

BACKGROUND

Systemic lupus erythematosus (SLE) patients have a higher risk of acute myocardial infarction (AMI) compared to the general population. However, the underlying common mechanism of this association is not fully understood. This study aims to investigate the molecular mechanism of this complication.

METHODS

Gene expression profiles of SLE (GSE50772) and AMI (GSE66360) were obtained from the Gene Expression Omnibus (GEO) database. Common differentially expressed genes (DEGs) in SLE and AMI were identified, and functional annotation, protein-protein interaction (PPI) network analysis, module construction, and hub gene identification were performed. Additionally, transcription factor (TF)-gene regulatory network and TF-miRNA regulatory network were constructed for the hub genes.

RESULTS

70 common DEGs (7 downregulated genes and 63 upregulated genes) were identified and were mostly enriched in signaling pathways such as the IL-17 signaling pathway, TNF signaling pathway, lipid metabolism, and atherosclerosis. Using cytoHubba, 12 significant hub genes were identified, including IL1B, TNF, FOS, CXCL8, JUN, PTGS2, FN1, EGR1, CXCL1, DUSP1, MMP9, and ZFP36.

CONCLUSIONS

This study reveals a common pathogenesis of SLE and AMI and provides new perspectives for further mechanism research. The identified common pathways and hub genes may have important clinical implications for the prevention and treatment of AMI in SLE patients.