Note: Single-source report; awaiting corroboration.
Researchers supported by the NIH Common Fund’s 4D Nucleome program investigated how the three-dimensional folding of DNA in brain cells changes in Alzheimer’s disease and aging. The study examined postmortem brain tissue from individuals aged 75 or older, including 10 with Alzheimer's and 10 without. Tissue samples focused on the prefrontal cortex, a brain region notably affected in Alzheimer’s. The researchers observed differences in DNA folding patterns between cells from the two groups: distant DNA regions were often closer together in cells from Alzheimer’s patients, while neighboring DNA regions were less frequently adjacent. This spatial reorganization was linked to changes in chromatin, the complex of DNA and proteins within the cell nucleus. Normally, inactive, compact chromatin and active, loosely packed chromatin remain separate; however, in Alzheimer’s, these chromatin types intermingle more than usual. This increased mingling was associated with reduced activity in genes related to neuronal functions, suggesting a connection between chromatin structure and gene regulation in Alzheimer’s disease and aging.