Intracellular glutathione levels are involved in carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone-induced apoptosis in As4.1 juxtaglomerular cells

Abstract

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. In the present study, we investigated the involvement of reactive oxygen species (ROS) and glutathione (GSH) in FCCP-induced As4.1 juxtaglomerular cell death. Intracellular ROS levels were decreased by FCCP at the early time points (10-150 min) and increased at 48 h. FCCP inhibited the activity of Mn-superoxide dismutase (Mn-SOD) via down-regulating its protein expression. Ebselen (an antioxidant) significantly attenuated ROS levels in FCCP-treated cells, but did not prevent FCCP-induced cell death. Moreover, intracellular GSH content was rapidly diminished within 10 min of FCCP treatment, which was accompanied by a reduction of the mitochondrial membrane potential [MMP (∆ψm)]. L-buthionine sulfoximine (BSO, a GSH synthesis inhibitor) significantly augmented As4.1 cell death by FCCP. However, N-acetylcysteine (NAC, a GSH precursor and antioxidant) attenuated GSH depletion, MMP (∆ψm) loss and cell death in FCCP-treated As4.1 cells. In addition, NAC increased Mn-SOD activity and decreased ROS levels in FCCP-treated As4.1 cells. In conclusion, these results suggest that compared to ROS levels, intracellular GSH levels are more closely linked to FCCP-induced apoptosis in As4.1 juxtaglomerular cells.