Abstract
Neurosin is a predominant serine protease in the central nervous system (CNS) and has been shown to play a role in the clearance of α-synuclein (α-syn) which is centrally involved in the pathogenesis of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Although it has been previously shown that neurosin and α-syn colocalize and that neurosin degrades α-syn aggregates in vitro, it is not clear if neurosin is dysregulated in the brains of patients with PD/DLB and to what extent delivery of neurosin into the CNS might ameliorate the deficits associated with α-syn accumulation in vivo. We analyzed the levels of neurosin in the brains of patients with PD/DLB and in α-syn transgenic (tg) models. With increased accumulation of α-syn, we observed decreased neurosin expression. Lentiviral vector (LV) driven expression of neurosin in neuronal cell cultures reduced the accumulation of wild type but not A53T α-syn and prevented α-syn associated toxicity. Neuropathological analysis following delivery of LV-Neurosin to α-syn tg mice resulted in reduced accumulation of α-syn and reversal of neurodegenerative alterations in wild type but not A53T α-syn tg mice. Therefore, viral vector driven expression of neurosin may warrant further investigation as a potential therapeutic tool for DLB.