Chromatin Changes in the Aging of Stem Cells

Chromatin is the name given to the packed structure of nuclear DNA and surrounding molecules, tightly coiled in the center of the cell. Chromatin structure and the molecules responsible for regulating that structure are a part of the complex epigenetic systems that determine the pace of protein production, and thus cell behavior. Chromatin changes in characteristic ways with age, a situation that is far from fully mapped and understood, but is particularly important in stem cell aging. Stem cell populations become less active with age, most likely an evolved response to rising levels of tissue damage that acts to limit the incidence of cancer. The cost of that protection is a slow decline into organ failure, disease, and death. Safely restoring youthful function in the scores of different stem cell populations throughout the body is an important goal for the future of medicine. In most tissues, adult stem cells occupy a rare but powerful functional compartment, capable of differentiating into multiple tissue-specific lineages. Some stem cell types can remain quiescent until environmental signals prompt them to divide whereas other types continuously divide to repopulate lost or injured tissue. This process is critical and is harnessed during injury and disease to enhance tissue repair. Stem cells in adult tissues show dramatic reductions in regenerative capacity with age. Stem cells undergo replicative aging (due to repeat proliferative cycles), chronological aging (...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs