Are mitochondrial DNA mutations to blame for the appearance of age-related diseases?
Small changes in the sequence of mitochondrial DNA can cause degenerative diseases of the heart and skeletal muscles. This discovery, made by scientists at the University of California, sheds new light on degenerative diseases, including those associated with age, and provides additional evidence that mitochondria play an important role in human health.
According to the head of the work, Douglas Wallace, this discovery is important for solving the main dilemma encountered by attempts to treat hereditary degenerative diseases, including chronic heart and muscle diseases.
According to traditional beliefs, the cause of such diseases lies in mutations of genes encoded by nuclear DNA, but the most common degenerative diseases demonstrate inheritance patterns that do not comply with generally accepted laws of genetics. The authors demonstrated that the solution to this paradox lies in the ability of mitochondrial DNA mutations to cause degenerative diseases, similar in manifestations to hereditary diseases caused by chromosomal disorders.
The researchers artificially induced a relatively weak mutation of the mitochondrial DNA of mouse cells, which reduces the synthesis of the main enzyme that provides energy synthesis in mitochondria by 50%. After that, they used mouse embryonic stem cells with a female genotype to create a line of mice in which the mutation providing energy deficiency was transmitted through female germ cells. Mice with altered mitochondrial DNA looked normal at the beginning of life, but at one year of age they developed degenerative diseases of the heart and skeletal muscles, similar to similar human diseases.
Based on this, the authors suggested that mutations of mitochondrial DNA and other disorders of energy synthesis may be the cause of the development of age-associated degenerative diseases.
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily
22.02.2008