The involvement of TRPM2 on the MPP+-induced oxidative neurotoxicity and apoptosis in hippocampal neurons from neonatal mice: protective role of resveratrol

Parkinson's disease (PD) is an age-related chronic neurodegenerative disease. Although PD is known to be a result of damage to hippocampal neurons, its molecular mechanism has yet to be completely clarified. The neurodegeneration in hippocampal neurons has been suggested to include excessive production of reactive oxygen species (ROS). Mitochondrial dysfunction and disruption of intracellular Ca2+ homeostasis play the most important role in the increase in ROS production for the cells. Remarkably, it is stated in the literature that especially the change of Ca2+ homeostasis triggers neuronal degeneration. TRPM2 is a unique calcium-permeable nonselective cation channel, and densest in the numberless neuronal population. The current study aims to elucidate the effect of antioxidant resveratrol (Resv) on TRPM2-mediated oxidative stress (OS) induced by 1-methyl-4-phenylpyridinium (MPP) exposure in the primary mouse hippocampal neurons. The neurons were divided into four groups as Control, Resv , MPP, and MPP+ Resv. In the current results, the activation of TRPM2 was observed in primary hippocampal neurons with MPP incubation. TRPM2 channel expression levels in the MPP group increased in hippocampal neurons after MPP exposure. In addition, intracellular free Ca2+ concentration and TRPM2 channel currents were highest in MPP groups, although they were decreased by the Resv treatment. In addition, mitochondrial membrane depolarization, ROS, caspase-3, caspase-9, and apoptosis values induced by MPP decreased with resveratrol treatment. In conclusion, in our study, we observed that the dysregulation of OS-induced TRPM2 channel activation in hippocampal neurons exposed to MPP caused apoptotic cell death in neurons, while the use of resveratrol had a protective effect by reducing OS resources in the environment.