Hepatocyte growth factor protects hepatocytes against oxidative injury induced by ethanol metabolism

Hepatocyte growth factor (HGF) is involved in many cellular responses, such as mitogenesis and apoptosis protection; however, its effect against oxidative injury induced by ethanol metabolism is not well understood. The aim of this work was to address the mechanism of HGF-induced protection against ethanol-generated oxidative stress damage in the human cell line VL-17A (cytochrome P450 2E1/alcohol dehydrogenase-transfected HepG2 cells). Cells were pretreated with 50 ng/ml HGF for 12 h and then treated with 100 mM ethanol for 0-48 h. Some parameters of oxidative damage were evaluated. We found that ethanol induced peroxide formation (3.3-fold) and oxidative damage as judged by lipid peroxidation (5.4-fold). Damage was prevented by HGF. To address the mechanisms of HGF-induced protection we investigated the cellular antioxidant system. We found that HGF increased the GSH/GSSG ratio, as well as SOD1, catalase, and gamma-glutamylcysteine synthetase expression. To explore the signaling pathways involved in this process, VL-17A cells were pretreated with inhibitors against PI3K, Akt, and NF-kappaB. We found that all treatments decreased the expression of the antioxidant enzymes, thus abrogating the HGF-induced protection against oxidative stress. Our results demonstrate that HGF protects cells from the oxidative damage induced by ethanol metabolism by a mechanism driven by NF-kappaB and PI3K/Akt signaling.