Z-Guggulsterone alleviated renal fibrosis and G_(2)/M cycle arrest through Klotho/P53 signaling

OBJECTIVE Chronic kidney disease(CKD)has become a global public health problem with 10%-15%incidence rate,and inhibiting the renal interstitial fibrosis is considered to be a potential strategy to delay the progression of CKD.Z-Guggulsterone(Z-GS),an active compound from derived from Commiphora mukul,has been proved to be effective in various diseases.The present study aimes to determine the protective effect and the molecular mechanism of Z-GS on renal fibrosis.METHODS Unilateral ureteral obstruction(UUO)mice and hypoxia-induced HK-2 cells were used to simulate renal fibrosis in vitro and in vivo,respectively.The mice and cells were treated with different doses of Z-GS to observe the pharmacological action.Renal function,including Scr,BUN,and UA,were detected by commercial kits.H&E and Masson staining were performed to observe histopathological changes of kidney.Cell viability and LDH release of HK-2 cells were detected by commercial kits.Cell cycle distribution and apoptosis rate were analyzed by flow cytometry.Fibrosis markers were detected by immunohistochemistry and immunofluorescence analysis.Cell cycle related proteins and Klotho/p53 signaling were analyzed by Western blotting.RESULTS The results showed that Z-GS decreased the rise of Scr,BUN,and UA and lightened renal histopathological injury,which were induced by UUO.Besides,Z-GS administration alleviated renal fibrosis in mice by inhibiting the expressions ofα-SMA,TGF-βand collagenⅣ,and delayed G2/M cell cycle arrest by promoting the expressions of CDK1 and cyclinD1/B1 rate.Experiments in vitro indicated that Z-GS treatment significantly increased the cell viability while decreased the LDH release in hypoxia-induced HK-2 cells.In addition,hypoxia induced fibrosis and G2/M cycle arrest in HK-2 cells were retarded by Z-GS.The study of its possible mechanism exhibited that Z-GS treatment increased the level of Klotho and inhibited P53 level.Nevertheless,the effect of Z-GS on Klotho/P53 signaling was reversed by siRNA-Klotho.Moreover,siRNA-Klotho treatment eliminated the effects of Z-GS on G2/M cell cycle arrest and fibrosis.CONCLUSION This study clarified that Z-GS alleviated renal fibrosis and G2/M cycle arrest through Klotho/P53 signaling pathway.People who have suffered CKD may potentially benefit from treatment with Z-GS.