Landscape of Double-Stranded DNA Breaks in Postmortem Brains from Alzheimer's Disease and Non-Demented Individuals  Journal of Alzheimer's Disease
Background: Alzheimer's disease (AD) brains accumulate DNA double-strand breaks (DSBs), which could contribute to neurodegeneration and dysfunction. The genomic distribution of AD brain DSBs is unclear. Objective: To map genome-wide DSB distributions in AD and age-matched control brains. Results: The AD brains contained 18 times more DSBs than the control brains and the pattern of AD DNA DSBs differed from the control brain pattern. In conjunction with published genome, epigenome, and transcriptome analyses, our data revealed aberrant DSB formation correlates with AD-associated single-nucleotide polymorphisms (SNPs), increased chromatin accessibility, and upregulated gene expression. Conclusion: This study is the first to characterize the AD brain DSB landscape. Our data suggest in AD, an accumulation of DSBs at ectopic genomic loci could contribute to an aberrant upregulation of gene expression. Overall design: Methods: We obtained autopsy brain tissue from 3 AD and 3 age-matched control individuals. The donors were men between the ages of 78 to 91. Nuclei extracted from frontal cortex tissue were subjected to Cleavage Under Targets & Release UsingNuclease (CUT&RUN) assay with an antibody against g-H2AX, a marker of DSBformation. g-H2AX-enriched chromatins were purified and analyzed via high-throughput genomic sequencing.