Cuddles can repair a broken heart, according to a new study. I hope you’re ready for some more hugs.
The Daily Mail reports, “Researchers from Michigan State University found the ‘love hormone’ oxytocin, released during times of physical intimacy such as cuddling, kissing or sex, can stimulate the growth of new, healthy heart cells.
Initial studies in zebrafish, which have the remarkable ability to regrow damaged heart tissue, found they experience a 20-fold increase in oxytocin following a heart injury which stimulates the growth of specialised cells that migrate to the heart.”
According to their press release: Now, researchers from Michigan State University show that in zebrafish and human cell cultures, oxytocin has yet another, unsuspected, function: it stimulates stem cells derived from the heart’s outer layer (epicardium) to migrate into its middle layer (myocardium) and there develop into cardiomyocytes, muscle cells that generate heart contractions. This discovery could one day be used to promote the regeneration of the human heart after a heart attack. The results are published in Frontiers in Cell and Developmental Biology.
“Here we show that oxytocin, a neuropeptide also known as the love hormone, is capable of activating heart repair mechanisms in injured hearts in zebrafish and human cell cultures, opening the door to potential new therapies for heart regeneration in humans,” said Dr Aitor Aguirre, an assistant professor at the Department of Biomedical Engineering of Michigan State University, and the study’s senior author.
Stem-like cells can replenish cardiomyocytes
Cardiomyocetes typically die off in great numbers after a heart attack. Because they are highly specialized cells, they can’t replenish themselves. But previous studies have shown that a subset of cells in the epicardium can undergo reprogramming to become stem-like cells, called Epicardium-derived Progenitor Cells (EpiPCs), which can regenerate not only cardiomyocytes, but also other types of heart cells.
“Think of the EpiPCs as the stonemasons that repaired cathedrals in Europe in the Middle Ages,” explained Aguirre.
Zebrafish could teach us how to regenerate hearts more efficiently
Enter the zebrafish: famous for their extraordinary capacity for regenerating organs, including the brain, retina, internal organs, bone, and skin. They don’t suffer heart attacks, but its many predators are happy to take a bite out of any organ, including the heart – so zebrafish can regrow their heart when as much as a quarter of it has been lost. This is done partly by proliferation of cardiomyocytes, but also by EpiPCs. But how do the EpiPCs of zebrafish repair the heart so efficiently? And can we find a ‘magic bullet’ in zebrafish that could artificially boost the production of EpiPCs in humans?
Yes, and this ‘magic bullet’ appears to be oxytocin, argue the authors.
To reach this conclusion, the authors found that in zebrafish, within three days after cryoinjury – injury due to freezing – to the heart, the expression of the messenger RNA for oxytocin increases up to 20-fold in the brain. They further showed that this oxytocin then travels to the zebrafish epicardium and binds to the oxytocin receptor, triggering a molecular cascade that stimulates local cells to expand and develop into EpiPCs. These new EpiPCs then migrate to the zebrafish myocardium to develop into cardiomyocytes, blood vessels, and other important heart cells, to replace those which had been lost.”
Next time you want to snuggle up to someone close, tell them you’re just following the science.