Connections Between Epigenetic Aging and Nuclear DNA Damage

Today's open access paper reviews what is known of the connections between epigenetic aging and the nuclear DNA damage that occurs across a lifetime, and particularly in later life. Some of this DNA damage is more evidently connected with the epigenetic regulation that determines the packaging and structure of nuclear DNA, such as the activity of transposable elements, restrained in youth, but unleashed to copy themselves in later life, damaging genes as they do so. It is important to note that the relationship of cause and consequence between nuclear DNA damage and epigenetic change is likely a two-way street, particularly given the comparatively recent discovery that repeated double strand break repair causes epigenetic alterations characteristic of aging. While nuclear DNA damage raises the risk of cancer, such as via damage to cancer suppression genes, it is fortunately largely irrelevant, occurring in cells that have only a few replications left before hitting the Hayflick limit, and will therefore soon be removed from tissues, or in parts of the genome that are inactive. Outside of the cancer risk, and the epigenetic change noted above, it can be argued that only DNA damage in stem cells and progenitor cells is relevant to aging, as these mutations can spread throughout a tissue. The pattern of mutations in a tissue, some of which will potentially alter cell behavior in damaging ways, is known as somatic mosaicism. Proving that this causes issues beyond cancer ri...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs