How to accelerate the regeneration of the heart muscle?

Marina Astvatsaturyan, Echo of Moscow

Human heart muscle cells are able to multiply not only in the embryo, but also in the adult body – this was discovered with the help of the carbon-14 isotope, which appeared in the food chain of all people on the planet after the Cold War nuclear weapons tests.

In one of the recent works, it was shown that the heart muscle can still be forced to regenerate when a certain signaling mechanism is activated, normally active only in the myocardium of the embryo. A group of Swedish scientists led by Jonas Frisén from the Karolinska Institutet in Stockholm, in collaboration with physicists from the Lawrence Livermore National Laboratory of the United States, went further and demonstrated the possibility of the formation of new heart muscle cells, cardiomyocytes, in adults.

In a recent issue of Science (April 3, 2009), Friesen and co-authors described a method for determining the age of cells in the human body based on the fact that the DNA of all plants and animals included carbon-14 released into the atmosphere as a result of ground-based nuclear tests. In 1963, these tests were banned and the level of the carbon isotope began to fall, but what managed to enter the DNA corresponded to the concentration of carbon-14 in the atmosphere at the time of the formation of new cells. Thus, in people born before 1955, i.e. before the start of nuclear tests, cells with a carbon isotope content coinciding with a later period were found, which means that the cells were formed much later, when people were already adults, which finally refutes the idea that heart muscle cells are given to us from birth, that they can only increase, but not divide.

The research and mathematical modeling carried out by Friesen's group made it possible to calculate the proportion of "congenital" and new cardiomyocytes in the adult heart. It turned out that the 50-year-old heart consists of more than half of the cells that he had at the time of birth, and the renewal slows down over time. A 25-year-old heart replaces about 1% of cardiomyocytes per year, by the age of 75 this indicator is halved. "But even such a small rate of myocardial cell renewal may be enough to help people who need new heart muscle cells," says Charles Murry, a specialist in cardiovascular diseases from the University of Washington in Seattle. "We just need to find a way to slightly increase the fission rate, understand how it works, and start using it," he adds in a comment for Nature News.

The next stage, according to Friesen, will be to study whether cardiomyocytes are able to divide after a myocardial infarction. If so, that increasing the efficiency of this process can help the recovery of patients. The New York Times newspaper, speaking on behalf of Friesen's discovery with colleagues, in fairness notes that the dogma about the inability of the heart to produce new cardiomyocytes was shaken two decades before the current publication. In 1987, Dr. Piero Anversa from Harvard Medical School claimed that the heart muscle was being renewed, but was not heard.

Portal "Eternal youth" www.vechnayamolodost.ru14.04.2009