Researchers have found that oxytocin, often referred to as the “love hormone”, could be a promising avenue for developing a new treatment to regenerate the hearts of heart attack patients.
- Oxytocin is a neuropeptide (a type of hormone) produced by the hypothalamus in the brain. It is known to encourage social bonds, promote attachment and generate pleasurable feelings, for example from sex, love, physical exercise or art.
- But the hormone has many other functions, such as regulating ejaculation and testosterone production in men and regulating lactation and uterine contractions in women.
- Speaking of sex, oxytocin stimulates erections and orgasms. In women, it is believed to help sperm reach the egg. Abnormal amounts of oxytocin are linked to sex addiction.
Oxytocin, the hormone released during sex and associated with attachment in humans, could one day be used to support the regeneration of the human heart after a heart attack. This is revealed a new studypublished in the journal Frontiers in Cell and Developmental Biology. According to researchers from Michigan State University, the “love hormone” could stimulate the production of stem cells in the heart. The results are based on both tests performed on human cells cultured in the laboratory and experiments on zebrafish, which have a remarkable ability to self-repair.
“Here we show that oxytocin is able to activate cardiac repair mechanisms in injured hearts in zebrafish and human cell cultures, opening the door to potential new therapies for cardiac regeneration in humans.said lead author Dr. Aitor Aguirre, assistant professor in the Department of Biomedical Engineering at Michigan State University, in a communicated.
How does oxytocin heal the heart?
The research team reports that stimulation caused by oxytocin causes stem cells to migrate from the outer layer of the heart, or epicardium, to the middle layer, the myocardium. There, these stem cells turn into cardiomyocytes, muscle cells that allow heart contractions. However, after a heart attack, heart cells die in large numbers, especially cardiomyocytes. As they are highly specialized cells, they cannot reconstitute themselves.
However, previous studies have shown that a subset of stem cells called by English-speaking researchers “EpiPC” (primary epicardial derived cells) can be reprogrammed to become cardiomyocytes or other types of cardiac cells. These EpiPCs could therefore replace the dead cells essential to the proper functioning of the heart, thanks to the oxytocin which stimulates them. “Think of EpiPCs as the stonemasons who repaired cathedrals in Europe during the Middle Ages“, explains Dr. Aguirre. Only oxytocin, out of 14 other brain hormones tested in the laboratory, caused such an effect.
Love hormone helps zebrafish regrow its heart
But why is zebrafish so central to this new research? It may actually hold the key to cell regeneration. They are indeed known for their extraordinary abilities to regenerate their organs: the brain, the retina, the internal organs, the bones and the skin. Importantly, the zebrafish can regrow up to a quarter of its heart when it has lost part of it to a predator. This is made possible by the production of a very large number of cardiomyocytes and EpiPC, thanks to the stimulation caused by oxytocin. The new cells make their way to the myocardium of the zebrafish to develop into cardiomyocytes and other important heart cells, to replace those that are lost. After this first discovery, the study authors found that oxytocin had a similar effect on human stem cells grown in the laboratory.
The researchers nevertheless underlined that new clinical trials in animals and humans were still necessary to move forward on this promising track.