Stem cells allow you to put in order the sick heart of monkeys
Heart diseases kill more people than any other diseases. In our time, cardiovascular diseases, in fact, have acquired the character of an epidemic - too much of a specific way of life leads most people. Stress, sedentary lifestyle, abundant nutrition, lack of physical exertion - all this leads to health problems, including cardiovascular diseases.
Modern medicine allows patients who have experienced, for example, myocardial infarction, to recover. With deep necrosis of the walls of the heart, a scar is formed from connective tissue. This fabric is less elastic than the surrounding "working" fabric. Therefore, the heart in the area of the scar is reduced much less efficiently than in other parts. And this, in turn, leads to impaired blood circulation.
Doctors identify 2 types of heart damage in case of a heart
attack : 1. Penetrating myocardial infarction (endocardium, myocardium and epicardium are damaged);
2. Non-penetrating myocardial infarction (damage is limited only to the endocardium, or else part of the myocardium).
Alcohol abuse, smoking, excessively abundant food, “harmful products”, an inactive way of life, diabetes, age and heredity are traditionally considered to be risk factors for the appearance of a heart attack.
The more a person experiences heart attacks, the worse the heart works, and the harder it is to the whole body. Unfortunately, cardiac tissue is not restored, so damage to the heart has a cumulative effect. A fatal dependence is manifested here - the more damage the heart receives, the worse it works, and the higher the probability of receiving new damage. Until recently, it was impossible to solve this problem. But now, it seems, there is hope that the situation will change for the better in the near future.
Japanese scientists from Shinshu Universityfound that stem cells can promote the repair of heart tissue. Stem cells for the repair of the heart muscle can be taken from other primates. The results of experiments conducted on macaques, clearly show the improvement of the heart after the scientists carried out the relevant procedures. Most likely, scientists say, a person’s heart can also be “repaired” in the same way.
Stem cell transplantation from one organism to another to repair any damaged tissue is not a new idea. The novelty of the work of Japanese scientistsin that they have learned to avoid rejection of the transplanted tissue. Transplanted stem cells are usually recognized by the animal or human body as foreign inclusion. The immune system is activated, and the host organism starts the attack. As a result, the transplant is rejected.
Scientists from Shinshu University have learned how to select a donor with the maximum similarity of marker proteins from the donor and the recipient. The immune system usually recognizes foreign proteins of this type. But if you pick up similar proteins, the immune system can be “deceived”, and it will not activate the defense mechanism.
At first, scientists took stem cells and grew heart cells from them (the so-called cardiomyocytes). Then these cells were transplanted sequentially to five macaques that survived myocardial infarction. As it turned out, the cells successfully settled down and significantly improved the work of sick primate hearts. The monkeys were observed for three months, during which their condition gradually improved. In the first month, as scientists say, the heartbeat was unstable, but gradually the organism of the “patients” brought everything back to normal.
Unfortunately, the experiment was conducted with a small number of experimental primates. And the duration of the experiment is not too high. In order to confirm the successful recovery of the work of the primate heart after transplantation of cardiomyocytes, additional experiments are needed. Of course, they are already saying that the results shown by macaques suggest that it is possible to transfer this method of treating the heart to a person. But for now, it’s too early to talk about it.
On the other hand, the proposed method is clearly more effective than the previously used direct stem cell transplant. But stem cells are isolated, and the biological signals transmitted to them are formed and regulated by the extracellular matrix. As a resultstem cells do not always transform into the right tissue for the doctors in the right sequence. Japanese scientists grow ready-made cardiomyocytes from stem cells in advance, which, moreover, are not rejected by the host organism.
Ideally, scientists say cardiomyocytes should be grown from the patient’s own cells. This minimizes the risk of tissue rejection. Despite the selection of similar proteins, such a risk does exist.
“The results we obtained allow us to say that the transplantation performed according to our method is effective in terms of regeneration of the heart muscle of primates (not human). But it is necessary to conduct further research in order to study post-operative arrhythmia and its consequences, ”the scientists said in a statement.
The results of research Japanese published in the scientific journal Nature.