Last weekend, we visited a nursing home for the elderly. Most of them are suffering from Alzheimer’s disease (AD), which make them forget a lot of things, even their relatives and friends. As is known, Alzheimer’s disease is one of neurodegenerative diseases, which involves multiple pathologic processes and affect an estimated 1 in 10 people over age 65. Alzheimer’s is predicted to affect 1 in 85 people globally by 2050.
According to previous studies, mutations in key AD genes have been identified to cause the development of AD, while the exact cause of those cases is generally unknown. Recently, I is shown that alterations in epigenetic processes are also involved in the pathophysiology of AD. Of which, one of several epigenetic markers altered in AD brain is 5-methylcytosine [5mC], which is involved in many important biological processes such as gene imprinting, chromatin structure , and X-chromosome inactivation. In addition, 5mC also play important roles in aging, cellular differentiation, neuronal development, learning and memory. During the development of AD, low levels of 5-hydroxymethylcytosine (5hmC) are found in most tissues including liver, lung, and heart, while high levels are in brain.
Therefore, increased levels of DNA modifications in the brain may be a biomarker of AD and the related DNA methylation inhibitors may be the potential way for AD therapy.