In all one’s life, the blood, hair and skin cells can be continuously regenerated, but the heart cells lose proliferative capacity soon after birth. UCLA researchers first clarified the reasons why adult heart can not regenerate. The study, published in a recently Journal of Cell Biology, could help people reprogram the patient’s heart, so that Cardiomyocytes cells can regain the ability to repair itself.
In the first week after birth, the mammalian heart can be regenerated, but this capability will soon be lost. However, perhaps we can make the heart regain this ability, the senior author of the article Dr. Robb MacLellan said.
In the process of human development, the proliferation of cardiomyocytes generated by precursor stem cells form the heart. Once the heart is formed, myocardial cells will change its status form immature cells into mature cells that can not be proliferated. However, the newt heart cells can change back and forth between the two states, to repair heart damage in time.
MacLellan noted that the reason for adult cardiac cells can not regenerating is simple. When myocardial cells are in the immature state they do not shrink well, while shrink capacity is quite essential for heart function. The human body is larger than the newt, and we need stronger systolic to maintain blood pressure and blood circulation. “In order to achieve more efficient and more powerful cardiac heart, we have to give up the ability of myocardial regeneration in evolution.” MacLellan said.
Studies have shown that transient knockdown block cell cycle proteins, can make adult cardiac cells re-enter the cell cycle, and then make them change into a state that can proliferate. However, this therapy must be reversible, and the effect should disappear after the repair, avoiding cardiomyocytes be mature again. Currently, MacLellan along with his team members are trying to send siRNA into the heart with nanoparticles, knocking down the proteins that make cardiomyocytes maintained the state of mature.
During the heart attack, cardiac cells will die and form scar tissue. By reprogramming, We can easily locate the damaged place and let the cardiomyocytes rejuvenate, and back into the state when they have the ability to regenerate.
Recent years, embryonic stem cells or pluripotent stem cells are used frequently for cardiac regeneration. “I think, it is possible to push myocardial cells regeneration right in the body.” MacLellan commented.