Scientists in Israel and Australia have discovered a way to regrow heart muscle cells, a breakthrough that may have major implications for heart attack victims. According to World Health Organization (WHO) statistics, coronary heart disease is the number one cause of death in the State of Israel.
Researchers at the Weizmann Institute of Science in Rehovot and the Victor Chang Institute in Sydney have discovered a way to stimulate the growth of heart muscle cells, according to the study’s principal investigator, molecular biologist Gabriele D’Uva.
Professor Richard Harvey of the Victor Chang Cardiac Research Institute, a key member of the team, spoke with The Guardian newspaper about the findings, which were published Tuesday in the scientific journal, ‘Nature Cell Biology.’
“There’s always been an intense interest in the mechanism salamanders and fish use which makes them capable of heart regeneration,” Harvey explained. “One thing they do is send their cardiomyocytes, or muscle cells, into a dormant state, which they then come out of to go into a proliferative state – which means they start dividing rapidly and replacing lost cardiomyocytes.
“There are various theories why the human heart cannot do that, one being that our more sophisticated immune system has come at a cost, and because human cardiomyocytes are in a deeper state of quiescence, that has made it very difficult to stimulate them to divide,” he continued.
While studying lab mice, however, the team discovered a way to overcome that barrier, at least in the lab, by stimulating a signalling system in the heart that is driven by a hormone called neuregulin.
When neuregulin was stimulated, heart muscle cells divided “spectacularly” in both adolescent and adult mice. However, in humans this hormone is blunted about a week after birth. Likewise, it’s muted about 20 weeks after birth in mice as well, according to the research.
Triggering the neuregulin pathway following a heart attack in the mice led to a replacement of lost muscle, however – repairing the heart and helping it regain its former health, almost completely.
“We will now examine what else we can use, other than genes, to activate that pathway, and it could be that there are already drugs out there – used for other conditions and regarded as safe – that can trigger this response in humans,” Harvey told The Guardian.
“The dream is that one day we will be able to regenerate damaged heart tissue much like a salamander can regrow a new limb if it is bitten off by a predator.”