Smokers Have Rapid Aging Defect

By Daniel J. DeNoon
WebMD Health News

Reviewed By Louise Chang, MD

Feb. 6, 2009 -- Cigarette smoke causes the same cellular defect seen in people with Werner's syndrome -- a rare genetic disease that makes people age very fast.

Smoking speeds the aging process, causing smokers to die about 10 years before their time. Now researchers may have found a clue to this process, giving them unexpected new paths to treatment.

The clue comes from the observation that smokers aren't the only people who age too fast. In their 20s, people with a rare genetic disorder called Werner's syndrome get gray hair, thin skin, and hoarse voices.

They soon develop cataracts, diabetes, hardening of the arteries, and weak bones. In their 40s or 50s, they tend to die of heart disease and cancer.

Smokers also age prematurely and tend to die of heart disease and cancer. Might there be a link?

Yes, say University of Iowa researchers Toru Nyunoya, MD, and colleagues.

Werner's syndrome is caused by a mutation in a gene called WRN. The gene makes the WRN protein that protects and repairs DNA in every cell of the body.

Nyunoya and colleagues collected lung cells from smokers with emphysema. Sure enough, the cells had too little WRN protein. The smokers' WRN genes were normal, but something was keeping them from making enough WRN.

When the researchers cultured lung cells in the laboratory, they found that cigarette smoke extract decreased the cell's WRN production -- and made the cells age more quickly. Cells genetically engineered to make too much WRN were not as strongly affected by the smoke extract.

"Our study may support efforts to target Werner's syndrome protein for use in developing treatments for smoking-related conditions such as emphysema," Nyunoya said in a news release.

The findings appear in the Feb. 6 issue of the American Journal of Respiratory and Critical Care Medicine.

SOURCES: Nyunoya, T. American Journal of Respiratory and Critical Care Medicine, Feb. 6, 2009; vol 179: pp 279-287. News release, University of Iowa. News release, American Thoracic Society. National Library of Medicine Genetics Home Reference, "Werner Syndrome," accessed online Feb. 5, 2009.

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