Extracellular α-synuclein--a possible initiator of inflammation in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease involving the loss of dopamine-producing neurons of the substantia nigra and the presence of Lewy bodies which contain high levels of α-synuclein. Although the causative factors of PD remain unclear, the progression of PD is accompanied by a highly localized inflammatory response mediated by reactive microglia. Recently, attention has focused on the relationship between α-synuclein and microglial activation. This review examines the role of α-synuclein on microglia in PD pathogenesis and progression, we also discuss the way of α-synuclein induced microglial activation.