Researchers at the California Institute of Technology and the University of California have found a new way to reverse cell damage that builds up with age. It consists in removing mutated DNA from mitochondria. The article of scientists was published in the journal Nature Communications. The MedicalXPress edition tells briefly about the discovery.
In every cell of the human body (with the exception of red blood cells) there are hundreds or thousands of mitochondria. These organelles are involved in the production of energy for metabolic reactions. They also contain the DNA (mtDNA) from which the mitochondrial genome is formed. Since the mechanisms of genome repair in organelles are not as well developed as in the nucleus, both mutated and normal mtDNA are often found in the same cell. When genetic differences reach a critical level, the cell dies.
Scientists have bred genetically modified fruit flies (Drosophila), whose mitochondrial genome in muscle cells is susceptible to random mutations. Changes in mtDNA affect muscles, reducing the ability of insects to fly, which makes Drosophila a convenient model organism for studying aging processes. In humans, aging processes also affect muscle function, causing sarcopenia and other disorders.
Cells can get rid of damaged mtDNA through the mitophagy process, which destroys defective mitochondria. The researchers found that when they stimulated the genes responsible for mitophagy, the DNA regions, analogs of which contribute to the development of Parkinson's disease in humans, decreased their activity. Thus, overexpression of the Parkin gene reduces the proportion of mutant mtDNA from 76 to 5 percent. According to scientists, this helps to normalize cellular processes.
The authors of the article plan to search for drugs that could cause the same effect. Researchers believe that in the future, people will be able to periodically undergo cellular cleansing procedures to remove damaged mtDNA from the brain, muscles and other tissues.