Fig. 2
From: Methylation as a key regulator of Tau aggregation and neuronal health in Alzheimer’s disease
Epigenetic regulation via methylation in microglia and neurons in Alzheimer’s disease. Epigenetic changes in methylation signatures occurs both in microglia and neurons during AD. Gene specific DNA hypomethylation or changes in histone methylation signatures in microglia and neurons result in altered immune function and genomic integrity respectively. Microglia is subjected to stimulation by aggregate species such as oligomers which produce different epigenetic makeups in primed and naïve microglia. DNA methyl transferase DNMT3L has been found to be upregulated in AD after LPS stimulation, suggesting its possible role in microglial activation. On the other hand, hypomethylation at H3K3Me3 on TNF-α and IL-1β promoters is associated with immunosuppression. In case of neurons, CpG hypomethylation occurs at BRCA1 (breast cancer 1) promoter in AD. This results in reduced BRCA1 levels leading to impaired DNA repair leading to neurodegeneration