Friday, September 21, 2007

Aging and Stem Cells

The latest issue of Nature has a very interesting News and Views piece on stem cells and aging. The piece is entitled "Ageing: From stem to stern" by Anne Brunet and Thomas Rando. Here is a sample:

The explosion of research on stem cells has given the promise of treatments for degenerative diseases of ageing, enhancement of the repair of damaged tissues and possibly even slowing of decline-in-function that occurs with advancing age. But how stem cells are affected by the ageing process, and whether such changes are a cause or a consequence of organismal ageing, remain unclear1. Three research teams have recently reported their findings on how age-related accumulation of DNA damage and changes in global patterns of gene expression might lead to the decline of stem-cell function.

....The authors converge in their general conclusions that, with age, adult HSCs decline in function but not number, and that DNA damage and epigenetic modifications may limit the regenerative potential of these cells. They also agree that HSCs are not protected from age-induced damage and, in fact, ageing may result in an accumulation of DNA mutations in these cells, thereby increasing the risk of cancer.
...Would stem-cell 'enhancement', whether genetic or epigenetic, delay the ageing characteristics of a particular tissue or even lead to an extension of lifespan? Understanding what limits stem-cell function during ageing will be essential for the field of regenerative therapeutics, which proffers the hope that the remarkable potential of stem cells will be harnessed for the repair of injury and the treatment of diseases.