Scientists have discovered that the “love hormone” can truly heal your coronary heart

Oxytocin, generally often known as the “love hormone,” could at some point assist heal broken hearts after coronary heart assaults, researchers have discovered.

The neurohormone oxytocin is widely known for strengthening social bonds and producing pleasurable emotions, reminiscent of these related to intercourse, train, or artwork. Nevertheless, the hormone has a number of different features, reminiscent of lactation and uterine contractions in ladies, and regulation of ejaculation, sperm transport, and testosterone manufacturing in males.

Now, scientists! Michigan State University have proven that oxytocin has one other beforehand unknown operate in zebrafish and human cell cultures; it stimulates stem cells from the outer layer of the guts (the epicardium) to the center layer (the myocardium), the place they grow to be cardiomyocytes, muscle cells. which trigger the guts to contract. This discovering may at some point be used to restore the human coronary heart after a coronary heart assault. The researchers’ findings had been lately revealed in a journal Frontiers in Cell and Developmental Biology.

“Right here we present that oxytocin, a neuropeptide often known as the love hormone, is ready to activate cardiac restore mechanisms in injured hearts in zebrafish and human cell cultures, opening the door to potential new therapies for cardiac restore in people,” mentioned Dr. Aitor Aguirre, assistant professor of biomedical engineering at Michigan State College and senior writer of the research.

Stem cells can replenish cardiomyocytes

After myocardial infarction, cardiomyocytes usually die in massive numbers. They can’t be replenished as a result of they’re extremely specialised cells. Earlier analysis, nevertheless, has proven {that a} subset of cells within the epicardium will be reprogrammed to change into stem cells often known as epicardium-derived progenitor cells (EpiPCs), which may regenerate not solely cardiomyocytes but additionally different varieties of coronary heart cells.

“Consider the EpiPCs because the stonemasons who renovated cathedrals in Europe within the Center Ages,” Aguirre defined.

Sadly, the manufacturing of EpiPCs beneath pure situations is ineffective for human cardiac regeneration.

Zebrafish can train us tips on how to restore hearts extra effectively

Enter the zebrafish. recognized for his or her extraordinary capability to regenerate organs together with the mind, retina, inner organs, bones and pores and skin. They do not endure from coronary heart assaults, however its many predators are blissful to chunk off any organ, together with the guts, so zebrafish can regrow their coronary heart when 1 / 4 of it’s misplaced. That is finished partly by proliferating cardiomyocytes, but additionally by EpiPCs. However how do zebrafish EpiPCs regenerate the guts so successfully? And may we discover a “magic bullet” in zebrafish that may artificially stimulate the manufacturing of EpiPCs in people?

Sure, and this “magic bullet” seems to be oxytocin, the authors declare.

To succeed in this conclusion, the authors discovered that three days after cryoinjury in zebrafish, an damage induced by freezing, the expression of the cardiac, messenger;[{” attribute=””>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.

A similar effect on human tissue cultures

Crucially, the authors showed that oxytocin has a similar effect on human tissue in vitro. Oxytocin – but none of 14 other neurohormones tested here – stimulates cultures of human Induced Pluripotent Stem Cells (hIPSCs) to become EpiPCs, at up to twice the basal rate: a much stronger effect than other molecules previously shown to stimulate EpiPC production in mice. Conversely, genetic knock-down of the oxytocin receptor prevented the regenerative activation of human EpiPCs in culture. The authors also showed that the link between oxytocin and the stimulation of EpiPCs is the important ‘TGF-β signaling pathway’, known to regulate the growth, differentiation, and migration of cells.

Aguirre said: “These results show that it is likely that the stimulation by oxytocin of EpiPC production is evolutionary conserved in humans to a significant extent. Oxytocin is widely used in the clinic for other reasons, so repurposing for patients after heart damage is not a long stretch of the imagination. Even if heart regeneration is only partial, the benefits for patients could be enormous.”

Aguirre concluded: “Next, we need to look at oxytocin in humans after cardiac injury. Oxytocin itself is short-lived in circulation, so its effects in humans might be hindered by that. Drugs specifically designed with a longer half-life or more potency might be useful in this setting. Overall, pre-clinical trials in animals and clinical trials in humans are necessary to move forward.”

Reference: “Oxytocin promotes epicardial cell activation and heart regeneration after cardiac injury” by Aaron H. Wasserman, Amanda R. Huang, Yonatan R. Lewis-Israeli, McKenna D. Dooley, Allison L. Mitchell, Manigandan Venkatesan and Aitor Aguirre, 30 September 2022, Frontiers in Cell and Developmental Biology.
DOI: 10.3389/fcell.2022.985298

The study was funded by the National Institutes of Health, the American Heart Association, and the Spectrum-MSU Foundation.