Protective effects of N-acetylcysteine amide (NACA) on gentamicin-induced apoptosis in LLC-PK1 cells.

Aim: Apoptosis plays a critical role in the pathogenesis of gentamicin (Gen)-induced nephrotoxicity. However, the underlying molecular mechanisms still remain unclear. In this study, we addressed the role of p38 mitogen-activated protein kinase (MAPK)/inducible nitric oxide synthase (iNOS) signaling pathway in Gen-induced nephrotoxicity and evaluated the protective effect of the free-radical scavenger N-acetylcysteine amide (NACA). Methods: Pig kidney epithelial cells (LLC-PK1) cells were exposed to Gen for variable times and doses. Cytotoxicity was assessed by morphology and by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Protein expression was assessed by Western blotting. Results: Exposure to Gen-induced apoptosis in a dose-dependent and time-dependent manner was assessed by DNA content analysis and poly ADP ribose polymerase (PARP) cleavage. Gen caused increased phosphorylation of p38 MAPK and induction of iNOS. This was accompanied by a significant upregulation of Bax an...