Placental stem cells found to regenerate heart cells after heart attack

According to the World Health Organization, cardiovascular diseases are the biggest killers of people in modern times, and it's largely due to the heart's inability to repair itself properly. Even if a person survives the initial cardiac arrest event, scar tissue renders the heart less effective at pumping blood and more likely to suffer future heart attacks.

Stem cells have long been investigated as a solution, but despite their regenerative prowess in other parts of the body, they've not been as successful in matters of the heart. Injecting stem cells into the heart can cause complications, and it turns out that cardiac stem cells might not even exist. Other studies have tried using stem cell "messengers" instead, or converting other heart cells into beating heart cells.

For the new study, researchers from the Icahn School of Medicine at Mount Sinai examined Cdx2 cells, a kind of stem cell derived from the placenta that has previously shown particular promise in repairing heart tissue.

By the three-month mark, every mouse in the Cdx2 group showed regeneration of healthy heart tissue, forming new cardiomyocytes – the heart muscle cells that beat – as well as new blood vessels. Meanwhile the other two groups showed no sign of regeneration, and many went into heart failure.

The results are exciting for a number of reasons. "Cdx2 cells have historically been thought to only generate the placenta in early embryonic development, but never before were shown to have the ability to regenerate other organs, which is why this is so exciting," says Hina Chaudhry, principal investigator of the study.