Exercise may prevent stress on telomeres, a measure of cell health

Jennifer O'Brien - UCSF scientists are reporting several studies showing that psychological stress leads to shorter telomeres – the protective caps on the ends of chromosomes that are a measure of cell age and, thus, health. The findings also suggest that exercise may prevent this damage.

The team focused on three groups: post-menopausal women who were the primary caregivers for a family member with dementia; young to middle-aged adults with post-traumatic stress disorder; and healthy, non-smoking women ages 50 to 65 years.

They examined telomeres in leukocytes, or white blood cells, of the immune system, which defends the body against both infectious agents and cell damage.

"Our findings suggest that traumatic and chronic stressful life events are associated with shortening of telomeres in cells of the immune system, but that physical activity may moderate this impact," said co-author Jue Lin, PhD, associate research biochemist in the laboratory of senior author and Nobel laureate Elizabeth Blackburn, PhD, professor of biochemistry and biophysics at UCSF.

Lin presented the findings in a poster session on Monday, April 4, 2011, at the AACR 102nd Annual Meeting 2011.

Telomeres are tiny units of DNA at the ends of chromosomes that protect and stabilize chromosomes. Every time a cell divides, some telomeres drop off. After a certain number of cell divisions, which varies depending on the cell type, the telomeres reach a critical length and the cell typically dies. Sometimes, however, the cells cease to divide and are subjected to genomic instability, promoting inflammation in the body.

Scientists have known for more than a decade that the length of telomeres in immune system cells is a marker of cell aging. In recent years, they have discovered that shorter telomeres are associated with a broad range of aging-related diseases and are predictive of incidence and poor prognosis of cardiovascular disease and a variety of cancers.

A 2004 study led by Blackburn and UCSF colleague Elissa Epel, PhD, associate professor of psychiatry, suggested that psychological stress may impact the length of telomeres in immune system cells. They reported that the perception of psychological stress in female caregivers of chronically sick children was related to shorter telomeres in lymphocytes, key cells of the immune system. This offered the first evidence that telomere maintenance potentially mediates the well documented detrimental effects of stress on health. ...

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