ABSTRACT
BACKGROUND: Although É-synuclein (É-syn) spreading in age-related neurodegenerative diseases such as Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) has been extensively investigated, the role of aging in the manifestation of disease remains unclear. METHODS: We explored the role of aging and inflammation in the pathogenesis of synucleinopathies in a mouse model of DLB/PD initiated by intrastriatal injection of É-syn preformed fibrils (pff). RESULTS: We found that aged mice showed more extensive accumulation of É-syn in selected brain regions and behavioral deficits that were associated with greater infiltration of T cells and microgliosis. Microglial inflammatory gene expression induced by É-syn-pff injection in young mice had hallmarks of aged microglia, indicating that enhanced age-associated pathologies may result from inflammatory synergy between aging and the effects of É-syn aggregation. Based on the transcriptomics analysis projected from Ingenuity Pathway Analysis, we found a network that included colony stimulating factor 2 (CSF2), LPS related genes, TNFÉ and poly rl:rC-RNA as common regulators. CONCLUSIONS: We propose that aging related inflammation (eg: CSF2) influences outcomes of pathological spreading of É-syn and suggest that targeting neuro-immune responses might be important in developing treatments for DLB/PD.
