Relationship of miRNA-146a to systemic lupus erythematosus: A PRISMA-compliant meta-analysis

LncRNA TUG1 relieves renal mesangial cell injury by modulating the miR-153-3p/Bcl-2 axis in lupus nephritis

BACKGROUND

Lupus nephritis (LN) is one of the most common and serious complications of systemic lupus erythematosus. Our experiments aimed to evaluate the molecular mechanisms of long noncoding RNA (lncRNA) TUG1 in a human renal mesangial cell (HRMC) model of LN.

METHODS

Cells were treated with lipopolysaccharide (LPS) to induce inflammatory damage. StarBase, TargetScan, and a luciferase reporter assay were used to predict and confirm the interactions between lncRNA TUG1, miR-153-3p, and Bcl-2. We determined the lncRNA TUG1 and miR-153-3p levels in LPS-induced HRMCs using quantitative reverse transcription PCR (RT-qPCR). MTT and flow cytometry analyses were used to detect HRMC proliferation and apoptosis, respectively. In addition, the expression of the apoptosis-related proteins Bax and Bcl-2 was evaluated using western blot analysis and RT-qPCR. Lastly, the secretion of inflammatory cytokines (IL-1β, IL-6, and TNF-α) was assessed using ELISA.

RESULTS

miR-153-3p directly targeted lncRNA TUG1. The level of lncRNA TUG1 was remarkably lower and miR-153-3p expression was markedly higher in LPS-treated HRMCs than in untreated cells. Transfection with TUG1-plasmid relieved LPS-induced HRMC injury, as evidenced by increased cell viability, inhibited apoptotic cells, reduced Bax expression, increased Bcl-2 level, and reduced secretion of inflammatory cytokines. Importantly, these findings were reversed by miR-153-3p mimic. We also found that miR-153-3p directly targeted Bcl-2 and negatively regulated Bcl-2 expression in HRMCs. In addition, our findings suggest that miR-153-3p inhibitor relieved LPS-induced HRMC injury via the upregulation of Bcl-2.

CONCLUSION

lncRNA TUG1 alleviated LPS-induced HRMC injury through regulation of the miR-153-3p/Bcl-2 axis in LN.

The critical importance of epigenetics in autoimmune-related skin diseases

Autoimmune-related skin diseases are a group of disorders with diverse etiology and pathophysiology involved in autoimmunity. Genetics and environmental factors may contribute to the development of these autoimmune disorders. Although the etiology and pathogenesis of these disorders are poorly understood, environmental variables that induce aberrant epigenetic regulations may provide some insights. Epigenetics is the study of heritable mechanisms that regulate gene expression without changing DNA sequences. The most important epigenetic mechanisms are DNA methylation, histone modification, and noncoding RNAs. In this review, we discuss the most recent findings regarding the function of epigenetic mechanisms in autoimmune-related skin disorders, including systemic lupus erythematosus, bullous skin diseases, psoriasis, and systemic sclerosis. These findings will expand our understanding and highlight the possible clinical applications of precision epigenetics approaches.

Downregulation of miR-137 Facilitates CD4+ T Cell Pyroptosis in Systemic Lupus Erythematosus via Stimulating AMPK Pathway

Objective

From the pathogenic mechanism point of view, systemic lupus erythematosus (SLE) features prominently in T lymphocyte apoptosis. Yet the regulatory mechanism underlying SLE cell apoptosis remains to be explored. This research intends to clarify the role played by miR-137 in SLE and the underlying mechanisms.

Methods

Twenty SLE patients (SLE group) and twenty healthy controls (control group) were selected, from whom peripheral blood CD4+ T cells were isolated via magnetic-activated cell sorting. Reverse transcription-polymerase chain reaction (RT-PCR) quantified miR-137 and AMP-activated protein kinase (AMPK) in CD4+ T cells. Further, transfection of miR-137 mimics and inhibitors into CD4+ T cells was carried out to alter miR levels. Levels of pyroptosis, apoptosis, and inflammatory- and pyroptosis-related proteins were determined through PI staining, flow cytometry, and Western blotting, respectively. A luciferase reporter gene assay identified the targeting relation between miR-137 and AMPK.

Results

SLE patients showed downregulated miR-137 and upregulated AMPK in CD4+ T cells than controls. miR-137 upregulation by miR-137 mimic transfection inhibited Jurkat cell pyroptosis and apoptosis at both mRNA and protein levels and suppressed NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome activity and pyroptosis-related protein gasdermin D (GSDMD), while miR-137 inhibitor transfection contributed to completely opposite effects. miR-137 directly targeted AMPK, as indicated by the luciferase reporter gene assay. Furthermore, miR-137 inhibitor intervention induced healthy CD4+ T cell pyroptosis and apoptosis via mediating AMPK, whereas miR-137 mimic transfection into CD4+ T cells of SLE patients leads to opposite results.

Conclusion

Upregulating miR-137 inhibits CD4+ T cell pyroptosis in SLE patients by modulating the AMPK pathway, suggesting the potential diagnostic and therapeutic role of miR-137 in SLE.

Identification and Contribution of Inflammation-Induced Novel MicroRNA in the Pathogenesis of Systemic Lupus Erythematosus

Recently microRNAs (miRNAs) have been recognized as powerful regulators of many genes and pathways involved in the pathogenesis of inflammatory diseases including Systemic Lupus Erythematosus (SLE). SLE is an autoimmune disease characterized by production of various autoantibodies, inflammatory immune cells, and dysregulation of epigenetic changes. Several candidate miRNAs regulating inflammation and autoimmunity in SLE are described. In this study, we found significant increases in the expression of miR21, miR25, and miR186 in peripheral blood mononuclear cells (PBMCs) of SLE patients compared to healthy controls. However, miR146a was significantly decreased in SLE patients compared to healthy controls and was negatively correlated with plasma estradiol levels and with SLE disease activity scores (SLEDAI). We also found that protein levels of IL-12 and IL-21 were significantly increased in SLE patients as compared to healthy controls. Further, our data shows that protein levels of IL-12 were positively correlated with miR21 expression and protein levels of IL-21 positively correlated with miR25 and miR186 expression in SLE patients. In addition, we found that levels of miR21, miR25, and miR186 positively correlated with SLEDAI and miR146a was negatively correlated in SLE patients. Thus, our data shows a dynamic interplay between disease pathogenesis and miRNA expression. This study has translational potential and may identify novel therapeutic targets in patients with SLE.

Biomarkers Associated with Organ-Specific Involvement in Juvenile Systemic Lupus Erythematosus

Juvenile systemic lupus erythematosus (JSLE) is characterised by onset before 18 years of age and more severe disease phenotype, increased morbidity and mortality compared to adult-onset SLE. Management strategies in JSLE rely heavily on evidence derived from adult-onset SLE studies; therefore, identifying biomarkers associated with the disease pathogenesis and reflecting particularities of JSLE clinical phenotype holds promise for better patient management and improved outcomes. This narrative review summarises the evidence related to various traditional and novel biomarkers that have shown a promising role in identifying and predicting specific organ involvement in JSLE and appraises the evidence regarding their clinical utility, focusing in particular on renal biomarkers, while also emphasising the research into cardiovascular, haematological, neurological, skin and joint disease-related JSLE biomarkers, as well as genetic biomarkers with potential clinical applications.