New findings identify a mechanism that accelerates aging in the brain and gives rise to Alzheimer's disease.
The findings center on “enhancers”, which turn the activity of genes up or down based on influences like aging and environmental factors. Comparing enhancers in brain cells of people at varying stages of Alzheimer's and healthy people has revealed that in normal aging, there is a progressive loss of important epigenetic marks on enhancers. This loss is accelerated in the brains of people with Alzheimer's.
These enhancers also over-activate a suite of genes involved in Alzheimer's pathology, spurring the formation of plaques and tangles, and reactivating the cell cycle in fully formed cells — a highly toxic combination.
The study also links enhancer changes to the rate of cognitive decline in Alzheimer's patients.
(2019). Epigenetic dysregulation of enhancers in neurons is associated with Alzheimer’s disease pathology and cognitive symptoms.
Nature Communications. 10(1), 1 - 14.