Copper induces oxidative stress and apoptosis through mitochondria-mediated pathway in chicken hepatocytes

The aim of this study was to investigate the effects of excessive copper (Cu)-induced cytotoxicity on oxidative stress and mitochondrial apoptosis in chicken hepatocytes. Chicken hepatocytes were cultured in medium in the absence and presence of copper sulfate (CuSO₄) (10, 50, 100 μM), in N-acetyl-L-cysteine (NAC) (1 mM), and the combination of CuSO₄ and NAC for 24 h. Morphologic observation and function, reactive oxygen species (ROS) level, antioxidant indices, nitric oxide (NO) content, mitochondrial membrane potential (MMP), and apoptosis-related mRNA and protein levels were determined. These results indicated that excessive Cu could induce release of intracellular lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT); increase levels of ROS, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), lipid peroxidation (LPO), and NO; decrease glutathione (GSH) content and MMP; upregulated Bak1, Bax, CytC, and Caspase3 mRNA and protein expression, inhibited Bcl2 mRNA and protein expression, and induced cell apoptosis in a dose effect. The Cu-caused changes of all above factors were alleviated by treatment with NAC. These results suggested that excessive Cu could induce oxidative stress and apoptosis via mitochondrial pathway in chicken hepatocytes.