These stem cells don't divide as frequently as other cell types since they need to maintain the integrity of their DNA, and multiple divisions lead to natural breaks in DNA. But when these stem cells are needed, their progeny can rapidly divide and are able to replenish the tissue with new cells." Without such replenishment, the mice without the normal reserves of ATR had graying hair and hair loss, and osteoporosis, within three to four months. The "10 to 20% of cells that escaped ATR deletion were able to reconstitute tissues in the engineered mice, at least initially. However, it appears that in the long run, even these cells were insufficient to maintain tissue integrity." The ATR deletion speeded up the slow loss of stem cells that come with aging. Of course, the...
Repairing the ATR that was deleted is the step in the research, and it is an open question as to whether this can forestall or even reverse aging.
Other applications of the research involve mutated DNA, which can also occur over time when the body taps into its reserves of adult stem cells. DNA damage can lead to the abnormal cell division that occurs in many cancers. However, possibly in the far or near future scientists may be able to forestall such degeneration in the aged body. Additional research will hopefully be possible, given the expanded access to stem cells that will enable further exploration into the mysteries of ATR.
