Effects of metformin on expression of AMP-activated protein kinase in rat glomerular mesangial cells / 中华肾脏病杂志

ABSTRACT

Objective To observe the effects of metformin on expression of Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK),nuclear factor-κB (NF-κB) and transforming growth factor β1 (TGF-β1) in cultured rat glomerular mesangial cells (MCs),and explore its renoprotective mechanisms.Methods MCs were cultured in the medium with normal glucose (group NG,5.6 mmol/L),high glucose (group HG,25mmol/L) and different concentrations of metformin (group M1,M2,M3).After 48 h exposure,the supernatants and MCs were collected.The expression of NF-κB and TGF-β1 mRNA was analyzed by real time-PCR.Total-AMPK,phospho-Thr-172 AMPK (p-AMPK),NF -κB p65 and TGF-β1 were visualized by Western blot.Results The real time-PCR and Western blot result showed MCs could express AMPK,NF-κB and TGF-β1 mRNA and protein.After stimulated by HG,the levels of intracellular NF-κB and TGF-β1 expressions were significantly increased compared with group NG (P ＜ 0.05); The levels of NF-κB and TGF-β1 were significantly decreased in group M1,M2 and group M3 compared with group HG in a dose-dependent manner.After stimulated by HG,the level of intracellular p-AMPK were down-regulated compared with group NG(all P ＜ 0.05); The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend (P ＜ 0.05),while the level of total-AMPK protein was unchanged with exposure to HG or different concentrations of mefformin(P ＞ 0.05).Conclusion Metformin can suppress the expression of NF-κB and TGF-β1 of glomerular MCs induced by HG via AMPK activation,which may partly contribute to its reno-protection.