October 26th, 2009

A 2009 Nobel Prize, Stress and Bullying at Work

Elizabeth Blackburn

Elizabeth Blackburn

The 2009 Nobel prize in physiology or medicine was won by Elizabeth Blackburn and two others for the discovery of “how chromosomes are protected by telomeres and the enzyme telomerase.” Telomere shortening makes humans age faster than they otherwise would. Blackburn, the 60-year old biochemist at the University of California, San Francisco , oversees diverse applications of the science from her lab. Read reporter Katherine Seligman’s profile of the scientist.

The most relevant aspect of her original 1970’s discovery is the study of the impact of exposure to stress on telomeres which shortens the stressed person’s life.

Our personal genetic codes are carried in chomosomes made up of DNA molecules . Telomeres are the caps on the ends of the string-like chromosomes. According to Blackburn, telomeres are “like the plastic ends of a shoelace.” Blackburn discovered that those caps protect the chromosomes during replication.

As we normally age, telomeres shorten and start to lose their protective capacity and we lose protection from diseases. As the caps wear down and the cells shut down, we age. Unprotected chromosomes are prone to mutations and cancer.

Elizabeth Blackburn and felllow Nobel winner, Carol Greider who originally was one of Blackburn’s graduate students, identified telomerase, the enzyme that maintains the stability of the protective telomere caps. Because telomerase rebuilds the telomere caps, the enzyme actually delays aging (called senescence by scientists). This was true in simple organisms (the initial work was with yeast cells) and in humans.

Activity by telomerase — the enzyme not the chomosome telomere caps themselves — is associated with cancer cells. Normal cells divide and lose their telomere caps and require telomerase to rebuild. Cancer cells, however, divide constantly (moreso than normal cells) yet somehow maintain their telomeres caps. Why do cancer cells not age and die? Telomerase may hold the key. Research continues.

For bullied targets, the Nobel winning research is directly relevant. There is a connection between stress (the human response to external psychosocial stressors) and aging at the cellular level. Long-term exposure to stress decreases telomerase activity resulting in telomere cap shortening leading to accelerated aging through premature cell death. Highly stressed women experienced the equivalent of an additional 9 to 17 years of aging when compared to non-stressed women.

In an illustrative study led by another of Blackburn’s former graduate students, Elissa Eppel, mothers were categorized as either “caregiving mothers” or “control mothers” based on whether or not they raised a chronically ill child or a healthy child and self-ratings of stress in their lives. Age affects telomere length. They are shorter as we age naturally.  Telomere length was the key measure of the impact of stress in this study. Sophisticated analyses of blood samples yielded telomere lengths and telomerase levels.

Self-ratings of stress were higher in caregiver moms. Within the caregiver group of 39 women, the more years of stressed caregiving, the shorter was the telomere length and the lower the telomerase activity level. And perceived stress was associated clearly with telomere length. The women with the highest stress had significantly lower telomerase activity level, exposing the ends of chromosomes to damage causing them to age faster.

In addition to shortened telomeres, highly stressed women in this study suffered more oxidative stress (cell damage from circulating free radicals that attack cellular DNA and RNA) which causes diseases like atherosclerosis, heart failure, heart attacks, Alzheimer’s, and chronic fatigue syndrome. The release of glucocorticoids, the primary stress hormones released by the adrenal gland during the body’s initial stress response is known to damage neurons. (Read Sapolsky’s Why Zebras Don’t Get Ulcers for a clear, non-scientific description of this elaborate physiological process.) Low telomerase levels are associated with premature death in adults from bone marrow failure and vulnerability to infections.

The researchers in this caregiving mother study raised the fascinating possibility that people who are more psychologically resistant to stress have longer telomeres than highly stressed individuals. And telomerase contributes to maintaining telomere length. Longer telomeres can extend the life span (in simpler, non-human, organisms). A missing link in the science is the confirmed association between psychological stress resistance and physiological (at the cellular level) stress resistance. But it makes sense.

You can also view Dr. Blackburn’s streaming and downloadable online video lectures about telomeres and telomerase.

Summary: chronic, unremitting stress causes problems at the cellular level that can prematurely age a person and render him or her vulnerable to diseases that kill. Moral of the story: stress is physiological and works at the cellular level. If your workplace has begun to cause you health problems, escape to live. Your body has already begun the process of decline and is aging you faster than necessary. Put your health first.

G. Namie


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This entry was posted on Monday, October 26th, 2009 at 8:01 am and is filed under Bullying-Related Research, Tutorials About Bullying. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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