Increased response to oxidative stress challenge of nano-copper-induced apoptosis in mesangial cells

Recently, many studies reported that nanosized copper particles (nano-Cu, the particle size was around 15-30 nm), one of the nanometer materials, could induce nephrotoxicity. To detect the effect of nano-Cu on mesangial cells (MCs), and investigate the underlying mechanism, MCs were treated with different concentrations of nano-Cu (1, 10, and 30 mu g/mL) to determine the oxidative stress and apoptotic changes. It was revealed that nano-Cu could induce a decreased viability in MCs together with a significant increase in the number of apoptotic cells by using cell counting kit-8 assay and flow cytometry. The apoptotic morphological changes induced by nano-Cu in MCs were demonstrated by Hochest33342 staining. Results showed that nano-Cu induced the nuclear fragmentation in MCs. Meanwhile, nano-Cu significantly increased the levels of reactive oxygen species, especially increased the levels of H2O2. It also decreased the activity of total SOD enzyme. In addition, when pre-treated with N-(2-mercaptopropionyl)-glycine, the cell apoptosis induced by nano-Cu was significantly decreased. These results suggest that oxidative stress plays an important role in the nano-Cu toxicity in MCs, which may be the main mechanism of nano-Cu-induced nephrotoxicity.