Roles of Microglia in Inflammation-Mediated Neurodegeneration: Models, Mechanisms, and Therapeutic Interventions for Parkinson's Disease

Parkinson's disease (PD), the second most common neurodegenerative disease, is characterized by a gradual, irreversible degeneration of the nigrostriatal dopaminergic pathway and consequent movement impairments including resting tremor, bradykinesia, muscle rigidity, and postural instability. While about 15% of PD cases have causative gene defects, most PD cases are sporadic and idiopathic. The current consensus suggests a multifactorial etiology of PD involving aging, genetic predisposition, and environmental exposure. Increasing evidence has documented important contribution of inflammation in PD pathogenesis. Here, we briefly review research on environmental exposure in the emergence of PD. We summarize the converging evidence on contribution of neuroinflammation, especially microglial activation, in the development of PD. We also highlight microglia-based therapeutic interventions for PD.