SITNFlash

Greetings SITN community! Below you will find this month's SITNewflash based on a recent research article in the journal Science explaining how the worm C. elegans may offer insight into how certain drugs may affect how long we live. You can refer to the links below the article for more information on this topic.

Also, keep your great science questions coming on our Question and Answer page ( http://sitn.hms.harvard.edu/qandawork/ ) and we'll keep working hard to get you good answers and explanations!

And don't forget to check out the announcements at the bottom of the page for information on public science seminar series that are going on at Harvard Medical School now! On March 23rd, medical school faculty will be speaking on the topic of stem cells.

The newest report from the Centers for Disease Control and Prevention in Atlanta indicates that the average American life expectancy has now reached the record height of 77.6 years. Will we continue to live longer and longer? Dr. S. Jay Olshansky at the University of Illinois at Chicago believes that in the year 2150, the maximum human lifespan will be 130, close to the current record of 122 years. Dr. Steven Austad at the University of Idaho predicts that someone already alive today will live to be 150 in the year 2150. The researchers have established a trust fund, on a $150 wager, that will grow until Jan. 1, 2150, when the heirs of the winner will receive the reward estimated to be worth $500 million! Since the current record is a “youthful” 122, extending lifespan to 150 will likely require advances in our current understanding of the aging process.

Dr. Robert Butler, President of the International Longevity Center in New York City , estimates that by 2050, the number of U.S. Centenarians--individuals who live to be 100--may reach 1 million, up from 50,454 Americans in the year 2000. While it is generally agreed upon that living to a very old age depends on a combination of both lifestyle and genetics, researchers who study aging have long sought to discover drugs to extend the human lifespan. Thus far, such a “fountain of youth” remains elusive. However, a new study published in the journal Science by geneticists from Washington University in St. Louis has shown that a class of antiseizure medications can extend the lifespan of a microscopic roundworm called C. elegans . While there is no evidence that the drugs slow the aging process in mice or humans, the study provides some exciting clues that brain activity may affect aging. Because worms and humans share similar genes, finding out how a drug works in a worm can be meaningful to a human as well. Since the lifespan of a researcher is limited, it is much easier to study a worm that lives approximately 21 days rather than a human who can live over 100 years!

In the study, 19 drugs were tested for their effect on aging in worms. The researchers found that ethosuximide, a preferred drug for treating seizures since the 1950s, had the greatest effect on the worm lifespan, extending average adult lifespan by 17%. The group then questioned whether the genes and proteins involved in controlling human seizures were similar to the ones that controlled worm lifespan. To address this question, they tested more drugs that had similar chemical structures to see if others made the worms live even longer. Significantly, the drug trimethadione extended worm lifespan by approximately 50%! This drug is also currently approved for human use and the treatment of seizures. In contrast, a drug called succinimide, that has a similar chemical structure but is unable to treat seizures, did not extend worm lifespan. These results suggest that drugs that treat seizures and therefore change the function of brain cells (neurons) may extend life!

Although the development of treatments for aging has proved challenging, researchers are beginning to gather information about the aging process itself. Such knowledge may prove useful in the development of anti-aging medications. Regardless of whether or not such a drug is developed, it will be interesting to know who won the bet between Drs. Olshansky and Austad 145 years from now!

Primary Source:

Evason, K., et al. “Anticonvulsant Medications Extend Worm Life-Span.” Science v 307 (Jan 14) 2005: 258-262.

Other great related material:

Wickelgren, I. “As the Worm Ages: Epilepsy Drugs Lengthen Nematode Life Span.” Science v 307 (Jan 14) 2005: 193. (Biomedicine Commentary)

CDC Report: http://www.cnn.com/2005/HEALTH/conditions/02/28/life.expectancy.reut/index.html

http://www.medicalnewstoday.com/medicalnews.php?newsid=18891

http://mednewsarchive.wustl.edu/medadmin/PAnews.nsf/0/C5FCD44467CBE5F986256F8700697B49

Gerontology Research Group: http://www.grg.org/