Mitochondrial beacons will predict life expectancy
Researchers at the National Institute of Biological Sciences in Beijing, working under the leadership of Meng-Qiu Dong, have developed a method for determining the age of nematodes by injecting them with a protein that fluoresces when interacting with free radicals in mitochondria.
Mitochondria are cellular organelles with their own DNA, whose function is to synthesize the energy necessary for the vital activity of the cell. For many years, experts have been following the hypothesis that the accumulation of free radicals, which are by-products of cell metabolism, stimulates the aging process due to the accumulation of DNA and protein damage. Mitochondria are at particularly high risk because they produce large amounts of free radicals, but do not have their own mechanisms for repairing DNA damage.
Researchers have developed a kind of "mitochondrial clock" that allows to estimate the life expectancy of nematodes by the number of "mito-flashes" – pulses of fluorescent glow emitted by a fluorophore protein introduced by them in the presence of free radicals.
The average life expectancy of nematodes is 21 days, and the peak of reproduction falls on the 3rd day of life.
The lowest activity of mitotic outbreaks on the 3rd day of life was observed in long-lived individuals, and the highest - in individuals who died before reaching 21 days of age.
Further experiments showed that the cells of nematode carriers of the mutation extending their life up to 39 days were characterized by a small number of mitotic outbreaks, and the peak of free radical production occurred at later periods of life. On the contrary, in worms with a life-shortening mutation, the frequency of mitotic outbreaks was higher, and the peak of their activity was observed at an earlier time.
A similar pattern was revealed when exposed to nematodes by environmental factors that obviously increase (short-term starvation and heat shock) and decrease (toxic herbicide) life expectancy.
Dun hopes that the approach developed by her group, which is the first non-invasive method for predicting life expectancy, will inspire other researchers to study the relationship between the activity of free radical production in mitochondria and the aging rate of other animals. She also believes that it will allow the study of energy production in the cells of patients with mitochondrial diseases.
Article by En-Zhi Shen et al. Mitoflash frequency in early adulthood predicts lifespan in Caenorhabditis elegans is published in the journal Nature.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Fight Aging!:
Visual Measurement of Mitochondrial Free Radicals Predicts Longevity in Nematodes.
13.02.2014