Abstract:

Toxicological effects of tetrabromobisphenol A (TBBPA) derivatives are highly concerned due to their increasing usages in diverse fields. It has been reported that tetrabromobisphenol A bis(2-hydroxyethyl ether) (TBBPA-BHEE), a representative of TBBPA derivatives, can induce cellular toxicity on rat pheochromocytoma cells (PC12) through reactive oxygen species mediated caspase activation. Nevertheless, underlying molecular mechanisms of intracellular reactive oxygen species (ROS) formation and effects of TBBPA-BHEE on PC12 energy metabolism remain unclear. This study developed the method for quantification of ATP, ADP, AMP and cAMP (cyclic AMP) simultaneously in PC12 with HPLC-ESI-MS/MS. The disturbance of TBBPA-BHEE on the respiratory chain oxidative phosphorylation and energy metabolism in PC12 cells was investigated via evaluation of the four compounds. It was shown that the ratio of ADP to ATP (ADP/ATP) decreased in PC12 cells after TBBPA-BHEE stimulation, implying that TBBPA-BHEE accelerated the process of respiratory chain oxidative phosphorylation in PC12 mitochondria. In addition, the concentrations of cAMP and the ratio of AMP to ATP (AMP/ATP) decreased in PC12 cells upon TBBPA-BHEE treatment, which suggested that TBBPA-BHEE potentially induced the mitochondrial dysfunction and led to the consequent energy metabolism imbalance in PC12. The results not only provided insight in the toxicological effects of TBBPA-BHEE, but also confirmed that HPLC-ESI-MS/MS was a powerful tool for studies on the cellular respiratory chain oxidative phosphorylation and energy metabolism.

Key words: energy metabolism, high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS), rat pheochromocytoma cells (PC12), respiratory chain oxidative phosphorylation, tetrabromobisphenol A (TBBPA) derivatives