Ginsenoside-Rg1 Protects against Renal Fibrosis by Regulating the Klotho/TGF-beta 1/Smad Signaling Pathway in Rats with Obstructive Nephropathy

摘要

Ginsenoside-Rg1 (G-Rg1) is an agent isolated from Panax ginseng that exerts anti-fibrotic effects; however, the mechanism is still unclear. Herein, we investigated whether G-Rg1 administration can mitigate or reverse unilateral ureteral obstruction (UUO)-induced renal fibrosis by regulating the Klotho/transforming growth factor (TGF)-beta 1/Smad signaling pathway in rats. Sprague-Dawley male rats were subjected to UUO, and rats in the treatment group were administered G-Rg1 or G-Rg1 plus Klotho short hairpin RNA interference (shRNA), while rats in the control and model groups were administered vehicle for 14d. Epithelial-mesenchymal transition (EMT) biomarkers and Klotho/TGF-/beta 1 signaling molecules were examined by immunohistochemistry, quantitative real-time PCR and Western blotting. Immunohistochemistry showed that UUO induced increased pro-fibrotic TGF-/beta 1 expression, overexpression of the mesenchymal marker, alpha-smooth muscle actin (alpha-SMA), and suppression of the epithelial marker, E-cadherin. Moreover, Western blotting analysis indicated that UUO promoted TGF-beta 1 and phosphorylated Smad3 (p-Smad3) expression (p0.01), but blocked Klotho and Smad7 expression (p0.01). After G-Rg1 administration, the UUO-induced TGF-beta 1 and p-Smad3 expression was suppressed (p0.01), whereas the reduced Klotho and Smad7 expression was reversed (p0.05), followed by amelioration of the EMT process. Intriguingly, the G-Rg1 effects were largely abrogated by Klotho knockdown. Furthermore, Klotho expression was upregulated by G-Rg1 treatment at the mRNA and protein levels. Our results suggest that G-Rg1 may be beneficial for ameliorating renal fibrosis by targeting Klotho/TGF-beta 1/Smad signaling in UUO rats.