Apelin-13 Protects PC12 Cells Against Methamphetamine-Induced Oxidative Stress, Autophagy and Apoptosis

Methamphetamine (METH) is a potent psychomotor stimulant that has a high potential for abuse in humans. In addition, it is neurotoxic, especially in dopaminergic neurons. Long-lasting exposure to METH causes psychosis and increases the risk of Parkinson's disease. Apelin-13 is a novel endogenous ligand which studies have shown that may have a neuroprotective effect. Therefore, we hypothesized that Apelin-13 might adequately prevent METH-induced neurotoxicity via the inhibition of apoptotic, autophagy, and ROS responses. In this study, PC12 cells were exposed to both METH (0.5, 1, 2, 3, 4, 6 mmol/L) and Apelin-13 (0.5, 1.0, 2.0, 4.0, 8.0 mu mol/L) in vitro for 24 h to measure determined dose, and then downstream pathways were measured to investigate apoptosis, autophagy, and ROS responses. The results have indicated that Apelin-13 decreased the apoptotic response post-METH exposure in PC12 cells by increasing cell viability, reducing apoptotic rates. In addition, the study has revealed Apelin-13 decreased gene expression of Beclin-1 by Real-Time PCR and LC3-II by western blotting in METH-induced PC12 cells, which demonstrated autophagy is reduced. In addition, this study has shown that Apelin-13 reduces intracellular ROS of METH-induced PC12 cells. These results support Apelin-13 to be investigated as a potential drug for treatment of neurodegenerative diseases. It is suggested that Apelin-13 is beneficial in reducing oxidative stress, which may also play an important role in the regulation of METH-triggered apoptotic response. Hence, these data indicate that Apelin-13 could potentially alleviate METH-induced neurotoxicity via the reduction of oxidative damages, apoptotic, and autophagy cell death.