Alpha-Synuclein-induced DNA Methylation and Gene Expression in Microglia

Synucleinopathy disorders are characterized by aggregates of a-synuclein (a-syn), which engage microglia to elicit a neuroinflammatory response. Here, we determined the gene expression and DNA methylation changes in microglia induced by aggregate a-syn. Transgenic murine Thy-1 promoter (mThy1)-Asyn mice overex-pressing human a-syn are a model of synucleinopathy. Microglia from 3 and 13-month-old mice were used to iso-late nucleic acids for methylated DNA and RNA-sequencing. a-Syn-regulated changes in gene expression and genomic methylation were determined and examined for functional enrichment followed by network analysis to further elucidate possible connections within the data. Microglial DNA isolated from our 3-month cohort had 5315 differentially methylated gene (DMG) changes, while RNA levels demonstrated a change in 119 differentially expressed genes (DEGs) between mThy1-Asyn mice and wild-type littermate controls. The 3-month DEGs and DMGs were highly associated with adhesion and migration signaling, suggesting a phenotypic transition from resting to active microglia. We observed 3742 DMGs and 3766 DEGs in 13-month mThy1-Asyn mice. These genes were often related to adhesion, migration, cell cycle, cellular metabolism, and immune response. Network analy-sis also showed increased cell mobility and inflammatory functions at 3 months, shifting to cell cycle, immune response, and metabolism changes at 13 months. We observed significant a-syn-induced methylation and gene expression changes in microglia. Our data suggest that a-syn overexpression initiates microglial activation lead-ing to neuroinflammation and cellular metabolic stresses, which is associated with disease progression. (c) 2021 IBRO. Published by Elsevier Ltd. All rights reserved.

Automated summary

Synucleinopathy disorders are characterized by the aggregation of a-synuclein in microglia, leading to neuroinflammatory responses. Gene expression and DNA methylation changes induced by a-syn aggregation were observed in microglia, with alterations in adhesion, migration, immune response, and metabolism pathways. The study suggests that a-syn overexpression activates microglia, resulting in neuroinflammation and cellular metabolic stresses, which may contribute to disease progression.