Al Green’s eternal riddle of how to mend a broken heart may finally have an answer as scientists discover the so-called “love hormone” may heal physical damage to the organ.
Oxytocin is a key chemical produced by our brain which is responsible for feelings of adoration, attachment and pleasure.
It is produced from close physical contact and this has earned it the nickname the “love hormone” or the “cuddle hormone”.
The societal implications of the hormone are well known, and scientists are now beginning to learn more about its physical role too. For example, it is thought to be involved in female lactation and male testosterone production.
But scientists at Michigan State University discovered something brand new when they applied the chemical to damaged heart tissue in a lab.
In both zebrafish and human cell cultures, oxytocin was able to make stem cells on the outside of the heart move deeper into the organ and turn into cardiomyocytes, the muscle cells responsible for heart contractions.
The research is in its early stages but the team are hopeful that the migrating cardiac stem cells may one day be able to help treat people with damage caused by heart attacks.
“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, a senior study author from Michigan State University.
Cardiomyocytes are the heavy lifters of the heart which enable it to pump blood and when they are damaged, they cannot repair due to them being highly specialised cells.
Oxytocin might be 'magic bullet'
As a result, the only hope of recovery is by taking versatile cells from the heart’s outer layer, called Epicardium-derived Progenitor Cells (EpiPCs), and turning them into cardiomyocytes.
But this process is slow and insufficient for meaningful treatment under natural conditions. The new study found that oxytocin might be the “magic bullet” to speed this process up.
“It is likely that the stimulation by oxytocin of EpiPC production is evolutionary conserved in humans to a significant extent,” Dr Aguirre said.
“Even if heart regeneration is only partial, the benefits for patients could be enormous.
“Next, we need to look at oxytocin in humans after cardiac injury. Oxytocin itself is short-lived in the 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.”
The results are published in Frontiers in Cell and Developmental Biology.
