Understanding the genetic, molecular, and cellular basis of ageing as the biggest risk factor of Alzheimer's disease

Alzheimer’s disease (AD) is one of the leading causes of dementia. The disease is characterized by atrophy of brain tissue, with major physiological, molecular, and anatomical changes being observed in the hippocampus and entorhinal region of the temporal lobe. The risk of developing this disease increases with advancing age. Ageing is a chronological phenomenon wherein a considerable decline is observed in physiological functions due to the complex interplay of various exogenous and endogenous factors such as genetic construction, elevated levels of ROS, decrease in the telomerase activity, and epigenetic factors such as methylation of DNA, histone modification etc. The physiological and molecular changes in an ageing person especially in neurons overlap considerably with those observed during the progression of AD. This article highlights various factors responsible for ageing as well as AD with the latest review of literature. Understanding the factors that bring about the fated changes and how they are associated with the progression of disease can open new doors to bring about better treatment options and help cure an otherwise incurable disease.