Cytotoxicity of propofol in human induced pluripotent stem cell-derived cardiomyocytes

Purpose Propofol infusion syndrome (PRIS) is a lethal condition caused by propofol overdose. Previous studies suggest that pathophysiological mechanisms underlying PRIS involve mitochondrial dysfunction; however, these mechanisms have not been fully elucidated. This study aimed to establish an experimental model of propofol-induced cytotoxicity using cultured human induced pluripotent stem cell (iPSC)-derived cardiomyocytes to determine the mechanisms behind propofol-induced mitochondrial dysfunction, and to evaluate the protective effects of coenzyme Q10 (CoQ10). Methods Human iPSC-derived cardiomyocytes were exposed to propofol (0, 2, 10, or 50 mu g/ml) with or without 5 mu M CoQ10. Mitochondrial function was assessed by measuring intracellular ATP, lactate concentrations in culture media, NAD(+)/NADH ratio, and the mitochondrial membrane potential. Propofol-induced cytotoxicity was evaluated by analysis of cell viability. Expression levels of genes associated with mitochondrial energy metabolism were determined by PCR. Intracellular morphological changes were analyzed by confocal microscopy. Results Treatment with 50 mu g/ml propofol for 48 h reduced cell viability. High concentrations of propofol (>= 10 mu g/ml) induced mitochondrial dysfunction accompanied by downregulation of gene expression of PGC-1alpha and its downstream targets (NDUFS8 and SDHB, which are involved in the respiratory chain reaction; and CPT1B, which regulates beta-oxidation). Cardiomyocytes co-treated with 5 mu M CoQ10 exhibited resistance to propofol-induced toxicity through recovery of gene expression. Conclusions Propofol-induced cytotoxicity in human iPSC-derived cardiomyocytes may be associated with mitochondrial dysfunction via downregulation of PGC-1alpha-regulated genes associated with mitochondrial energy metabolism. Co-treatment with CoQ10 protected cardiomyocytes from propofol-induced cytotoxicity.