A research group led by Professor Ji Fujio of the Graduate School of Pharmaceutical Sciences, Osaka University analyzed using a mouse myocarditis model and found that cardiomyocytes proliferate in the heart of an adult mouse during the process of spontaneous healing of myocarditis. Revealed for the first time in.
Until now, it has been thought that mammalian cardiomyocytes lose their proliferative capacity immediately after birth, and in the adult mammalian heart, cardiomyocyte proliferation does not contribute to the regeneration and repair of the injured heart. rice field.That is why regenerative therapy, in which iPS cells and the like are differentiated into cardiomyocytes and transplanted, is being studied as a treatment for patients with severe heart failure.However, the research group focused on the spontaneous recovery of heart function in many patients with viral myocarditis, and wondered if the adult mammalian heart also has some regenerative and repairing ability.
Therefore, using an experimental autoimmune myocarditis model in mice, we analyzed the properties of cardiomyocytes during the recovery process of the heart from inflammation.As a result, it was found that cardiomyocytes with a rotating cell cycle appear in the myocardial tissue during the recovery period from inflammation.We also found that counting the number of nuclei of cardiomyocytes before and after myocarditis, the proportion of proliferative mononuclear cardiomyocytes increased after myocarditis.
Next, we conducted an experiment to mark the originally existing cardiomyocytes with a "mark" and follow the subsequent course, and revealed that most of the proliferating cells were originally existing cardiomyocytes. bottom.Furthermore, it was discovered that activation of the STAT3 molecule, which is a signal transduction molecule (a molecule that transmits information from outside the cell), is essential for its proliferation.
In the future, it is expected that the technology to awaken the hidden regenerative ability of cardiomyocytes will be established, and that it will develop into a heart failure treatment strategy different from the cardiac regeneration treatment currently under development.
Paper information: [Scientific Reports] Adult murine cardiomyocytes exhibit regenerative activity with cell cycle reentry through STAT3 in the healing process of myocarditis.
