Extracellular cysteine/cystine redox potential affects mitochondrial func-tion in NAFLD LO2 cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effects of extracellular cysteine/cystine redox potential (EhCys/CySS) on the mitochondrial function of nonalcoholic fatty liver disease ( NAFLD) hepatocytes.METHODS:LO2 cells were incuba-ted with EhCys/CySS of the oxidized (0 mV), the normal (-80 mV), or the reduced (-150 mV) status medium, then treated with oleic acid to establish NAFLD model in vitro.DCFH-DA and MitoSOX were used as the fluorescent probes for determining reactive oxygen species (ROS).Apocynin (NADPH oxidase inhibitor), MitoQ10 (mitochondria-targeted an-tioxidant), rotenone (mitochondrial respiratory chain complex I inhibitor) and antimycin A (mitochondrial respiratory chain complex III inhibitor) were used to investigate the sources of ROS.RESULTS:An increase in ROS in LO2 cells by oleic acid was aggravated by the oxidized extracellular EhCys/CySS (0 mV), which was removed by the reduced EhCys/CySS (-150 mV) .ROS generation by 0 mV was significantly eliminated by MitoQ10 .ROS levels were dependent on ex-tracellular Eh Cys/CySS in rotenone treated LO2 cells.A decline of mitochondrial membrane potential in the cells with NAFLD was aggravated by 0 mV and reversed by -150 mV.CONCLUSION:The oxidized extracellular Eh Cys/CySS via inhibitiing of complex I intensifies ROS generation and reducing the mitochondrial membrane potential in the NAFLD hepa-tocytes, which were reversed by reduced Eh Cys/CySS.