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מדענים גילו את "שורש הבעיה" שגורמת להידרדרות במצב הבריאותי בהזדקנות

10/02/2011
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מדענים גילו את "שורש הבעיה" שגורמת להידרדרות במצב הבריאותי של מבוגר.

 

להלן ההסבר:

Scientists at Dana-Farber Cancer Institute say they have identified the root molecular cause of a variety of ills — waning energy, failure of the heart and other organs, metabolic disorders like diabetes — brought on by advanced age.

The scientists found that the basic cause of age-related health decline is malfunctioning telomeres — the end-caps on cells' chromosomes that protect them against DNA damage. As cells reach their pre-determined limit of times that they can divide, the telomeres become shortened and frayed, making the chromosomal ends vulnerable to increased rates of unrepaired DNA damage.

Faced with this increasing reservoir of injured DNA, cells activate a gene, p53, that sounds an alarm and shuts down the cells' normal growth and division cycle, ordering them to rest until the damagecan be repaired or, if not, to self-destruct.

Scientists previously had blamed this emergency shutdown and cell death for the age-related deterioration of organs whose cells divide rapidly and are rejuvenated by reserves of adult stem cells. Such tissues include skin, intestinal lining and blood cells, among others, which generate trillions of new cells each day of life.

However, left unanswered is how cells with less cell division, such as the heart or the liver, sustain equivalent levels of aging. The scientists felt if they could answer this mystery, they might gain new insights into how DNA damage might lead to age-related decline across all organs.

The new findings demonstrate that the telomere dysfunction and activation of p53 also trigger a wave of cellular and tissue degeneration that links telomeres to well-known mechanisms of aging that are not simply related to rapid growth and division. In other words, telomere dysfunction is not just one culprit in the declining health of advanced age — it's the kingpin, according to DePinho and his colleagues

http://nextbigfuture.com/2011/.....ng-is.html

http://health.usnews.com/healt.....identified

http://www.physorg.com/news/20.....tists.html

http://www.healthcanal.com/ger.....d-age.html

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