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

Abstract

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.

Keywords: Apoptosis; Copper; Hepatocyte; Mitochondrion; Oxidative stress.