Abstract
Diabetic nephropathy is one of most frequent complications of diabetes, and is the major cause of end-stage disease in diabetic patients. The present study investigated the roles and mechanisms of Rhein-8-O-β-D-glucopyranoside (Rg) protecting human mesangial cells (HMCs) from high glucose (HG)-induced apoptosis. Using a Cell Counting Kit-8 assay the proliferation of HMCs was analyzed, and flow cytometry was applied to detect apoptosis. The apoptosis-associated protein Bcl-2, caspase-3 and members of the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway were analyzed using a western blotting assay. HG significantly induced HMC apoptosis, and Rg markedly attenuated the HG-induced apoptosis. HG decreased the Bcl-2 expression and increased the caspase-3 expression, and Rg treatment recovered the expressions of Bcl-2 and caspase-3 affected by HG. The underlying mechanisms were further analyzed, and it was demonstrated that HG significantly upregulated the long intervening non-coding RNA (lincRNA) ANRIL expression level, downregulated let-7a expression and activated the TGF-β1/Smad signaling pathway; Rg treatment recovered the expressions of lincRNA ANRIL and let-7a, and inhibited the TGF-β1/Smad signaling pathway in the condition of HG. In conclusion, the present results suggested that Rg attenuated HG-induced apoptosis of HMCs by regulating the lincRNA ANRIL/let-7a/TGF-β1/Smad signaling pathway.