Clin Exp Nephrol. 2022 Jan 08.
BACKGROUND: Diabetic nephropathy (DN), a diabetic complication, is the leading cause of end-stage renal disease. KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1), a long non-coding RNA, has been unmasked to participate in the pathogenesis of DN. However, the specific mechanism by which KCNQ1OT1 regulates podocyte injury remains unclear.METHODS: Relative expression of KCNQ1OT1 was measured with quantitative real-time polymerase chain reaction (qRT-PCR). The levels of inflammatory cytokines were analyzed by enzyme linked immunosorbent assay (ELISA). The viability, proliferation, and apoptosis of high glucose (HG)-treated podocyte were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays. Protein levels were analyzed by western blotting. The regulatory mechanism of KCNQ1OT1 was surveyed by bioinformatics analysis, dual-luciferase reporter, and RNA immunoprecipitation (RIP) assays.
RESULTS: We observed an apparent upregulation in KCNQ1OT1 expression in serums of DN patients and HG-treated podocytes. Furthermore, KCNQ1OT1 downregulation alleviated HG-induced inflammation, proliferation repression, and apoptosis in podocytes. Notably, KCNQ1OT1 was identified as a miR-23b-3p sponge, and miR-23b-3p directly targeted Semaphorin-3A (Sema3A). Moreover, miR-23b-3p silencing reversed KCNQ1OT1 knockdown-mediated effects on inflammation, proliferation, and apoptosis of HG-induced podocytes. Also, Sema3A overexpression reversed the effects of miR-23b-3p mimic on inflammation, proliferation, and apoptosis of HG-induced podocytes. Importantly, KCNQ1OT1 regulated Sema3A expression by sponging miR-23b-3p.
CONCLUSIONS: HG-induced KCNQ1OT1 promoted inflammation, proliferation repression, and apoptosis of podocytes via increasing Sema3A expression through sponging miR-23b-3p. This study provided evidence to support the involvement of KCNQ1OT1 in the pathogenesis of DN.
Keywords: DN; KCNQ1OT1; Podocytes; Sema3A; miR-23b-3p