Pérdida de células madre correlacionado a envejecimiento prematuro en modelo animal, hallazgo de investigadores de PennContributed by: Anonymous · Views: 981
Contributed by: Anonymous · June 08, 2007 @ 05:57 AM MDT · Views: 981
Loss of Stem Cells Correlates with Premature Aging in Animal Study, Penn Researchers Find
Implications for Aging, Cancer Research
(PHILADELPHIA) – Researchers at the Abramson Family Cancer Research Institute of the University of Pennsylvania have found that deleting a gene important in embryo development leads to premature aging and loss of stem cell reservoirs in adult mice. This gene, ATR, is essential for the body’s response to damaged DNA, and mutations in proteins in the DNA damage response underlie certain types of cancer and other disorders in humans. This work appears in the inaugural issue of Cell Stem Cell.
ATR deletion leads to cortical (the dense surface part of bone) bone loss.
When the researchers deleted ATR in the tissues of adult mice, they noticed that the mice showed signs of premature aging, such as hair graying, hair loss, and osteoporosis, within three to four months.
To be able to renew itself, most tissues have a reservoir of specific adult stem cells. 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.
Hair follicle stem cells (green, top) are lost (below) from follicles during hair regeneration leading to alopecia, or hair loss.
“Think of aging as a slow loss of stem cells, a deterioration of pools of cells that reside in each tissue type,” says Brown. “We accelerated the aging process by wiping out a large fraction of these cells prematurely, in one fell swoop. Essentially, ATR-deleted mice start their young adulthood with two strikes against them in terms of long-term tissue maintenance, and so, they subsequently age before their time.”
With this new knowledge of how DNA repair, stem cells, and the aging process interconnect, Brown, first author Yaroslava Ruzankina, and Amma Asare are currently using this mouse model to discover compounds that preserve stem cells and may, consequentially, suppress aging.
This work was funded in part by the National Institute on Aging, the Abramson Family Cancer Research Institute, and the General Motors Cancer Research Scholars Program. Co-authors in addition to Brown are Ruzankina, Asare, Carolina Pinzon-Guzman, Tony Ong, Laura Pontano, George Cotsarelis, Valerie Zediak, Marielena Velez, and Avinash Bhandoola, all from Penn.
Courtesy Penn Medicine