Mitochondrial DNA Changes Key to Aging, Study Says
Posted on: Thursday, 27 May 2004, 06:00 CDT
Gray hair - or no hair - wrinkles and creaky joints are obvious reminders that you're not getting any younger.
Scientists in Sweden say aging begins in a more fundamental way - in the accumulation of tiny changes to a mysterious genetic component in cells called mitochondrial DNA.
Researchers describe the study as the first experimental evidence of this theory - at least in laboratory mice. They believe the finding could explain how humans age and how the body's systems begin to misfire, although more tests must bear out them out. The mouse results appear in the current issue of the journal Nature.
"It seems to be a universal phenomenon in mammals that you have this damage to mitochondrial DNA as you get older," said the study's senior author, Nils-Goran Larsson at the Karolinska Institute in Stockholm.
"But I and many others thought this was just a secondary phenomenon," Larsson said. "I think the importance of our paper is that we actually show these mutations can indeed cause several changes associated with aging."
Other scientists say the Swedish experiments clearly show that a high rate of mutation in mitochondrial DNA has an effect on aging.
"But that does not mean all aging is caused by mutations in mitochondrial DNA," said David Finkelstein of the National Institute on Aging, part of the National Institutes of Health.
In the experiments, the Swedish team used mice bred with a defective version of an enzyme responsible for maintaining mitochondrial DNA.
Mitochondria are tiny biochemical power plants in cells that convert food into energy. Mitochondria contain a strands of their own DNA that are separate from the cell nucleus where the body's genes reside.
The deterioration in the experimental mice started at 25 weeks - young adulthood in normal mice. They prematurely experienced a range of familiar age-related complaints, including baldness, osteoporosis, anemia, curvature of the spine and reduced fertility. The life span of the experimental mice was markedly reduced, with the median age of death at 48 weeks. The oldest of the experimental mice died before 61 weeks.
In normal mice, early aging signs appear at about 40 weeks. Emaciation and other signs of old age accumulate by 1.5 years, and lab mice typically live a little over 2 years.
On the Internet: National Institute on Aging: http:// www.nia.nih.gov
Related Articles
- America Celebrates Aging in Place Week, Oct. 12-18
- Moody Nolan and Antoine Predock Architect PC Selected for Design Shortlist for the Smithsonian Institution's National Museum of African American History and Culture
- Scientist Map DNA Of Ice Age Wooly Mammoth
- China Holdings Announces Contracting of China Electric and Design Institute (National AAA+) As Part of Engineering Experts Team
- MIT's Technology Review Announces 2006 ''TR35,'' the Top 35 Innovators Under the Age of 35; Christina Galitsky, Lawrence Berkeley National Laboratory, Named Humanitarian of the Year; Joshua Schachter, Del.Icio.Us, Named Innovator of the Year
- Of Worms, Mice & Men: Altering Rates of Aging
- Chairman of Conference on Aging to Address Impact of Boomers, at National Press Club, Dec. 9
- Aging Baby Boomers Once Again Affecting the Nation's Eating Habits
- Dinosaur DNA? New Patent Covers Prehistoric and Aged DNA
- DNA Boffin Dead, Aged 88
 |
 |
User Comments (0)
RSS Feeds