Abstract
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.