HGF protects rat mesangial cells from high-glucose-mediated oxidative stress

BACKGROUND: Oxidative stress has been considered to be a common pathogenetic factor of diabetic nephropathy. Recent observations suggested that hepatocyte growth factor (HGF) was an antioxidant growth factor; thus, its renoprotective effects in diabetic nephropathy might be related to antioxidant mechanism. The aim of the present study was to evaluate whether HGF could prevent rat mesangial cells (RMC) from high-glucose-mediated oxidative stress and explore its relevant mechanism. METHODS: RMC were cultured in 5.6 mM (NG) or 30 mM (HG) glucose in the absence or presence of HGF (20 ng/ml) and c-met inhibitor SU11274 (5 microM) for 24 h. RESULTS: c-met expression in HG was markedly increased. Enhanced oxidative stress was observed in HG as evidenced by elevated reactive oxygen species and malondialdehyde levels and decreased glutathione level, which was markedly attenuated by HGF. HGF also inhibited HG-induced p22(phox) and aldose reductase upregulation and prevented HG-reduced glutamate-cysteine ligase catalytic subunit (GCLC) expression through inhibiting USF binding to negative regulatory region of GCLC promoter. Reduced glucose-6-phosphate dehydrogenase activity and expression in RMC by HG was rescued by HGF. CONCLUSION: HGF could function as an antioxidant factor and protect against HG-mediated oxidative stress by enhancing ROS scavenging and suppressing ROS production.