Molecular biologists in the United States have discovered that people with Alzheimer’s disease are unusually likely to exhibit a set of 107 epigenetic markers that regulate the activity of around 40 genes in brain neurons and influence disease symptoms. The researchers suggest that these markers should be taken into account in the early diagnosis of dementia. Their findings were published in the scientific journal Nature Aging.
“We identified 107 epigenetic markers associated with Alzheimer’s disease, 12 of which affected at least two of its characteristic pathological features. A total of 38 markers were validated through analyses of other datasets. We also demonstrated that this set of markers could be used to diagnose Alzheimer’s disease and assess the risk of developing its more severe forms,” the researchers write.
The discovery was made by a team of American molecular biologists led by Professor Zhaoying Jin of the University of South Florida as part of a large-scale study investigating the role of epigenetic factors in the development and progression of Alzheimer’s disease. Various markers and features of DNA packaging have a substantial influence on the activity of numerous genes. Scientists have long been interested in how disruptions in the processes responsible for adding and removing these markers may contribute to the development of neurodegenerative diseases.
To investigate this question, the researchers assembled a collection of 1,250 prefrontal cortex samples from patients with Alzheimer’s disease, extracted DNA strands from the tissue, and examined the structure of more than 930,000 individual epigenetic markers. The biologists compared these data with a large number of biomarkers associated with the disease, as well as its symptoms, enabling them to identify variations in DNA packaging characteristic of people with Alzheimer’s disease.
In total, the researchers identified 107 epigenetic markers associated in various ways with the likelihood of developing Alzheimer’s disease, the accumulation of beta-amyloid and tau protein in the brain cells of affected individuals, and other pathological features of the condition. The scientists repeated the analysis using a separate dataset containing genetic information from 139 patients, confirming the association between Alzheimer’s disease and 38 epigenetic markers.
According to Professor Zhaoying Jin, these differences in DNA packaging influenced the activity of 67 genes. Some of them, including the APOE, ANK1, LPP, RIN3, and JADE2 regions, had previously been linked to Alzheimer’s disease.
The findings point to a potentially important role for epigenetic factors in the development of the disease, which should be considered in its diagnosis and in further research into the mechanisms underlying Alzheimer’s disease, the scientists conclude.
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