Human placental stem cells may have the potential to regenerate heart tissue after a heart attack, according to Mount Sinai researchers who have received a $2.9 million grant from the National Institutes of Health to study them. Their findings could lead to new therapies for repairing the heart and other organs.
Hina W. Chaudhry, MD, Director of Cardiovascular Regenerative Medicine at the Icahn School of Medicine at Mount Sinai, is the Principal Investigator for this four-year award.
"This is very exciting. These cells may represent the ideal cell type for heart repair, which has been very challenging because clinical trials of other cell types did not find much benefit," says Dr. Chaudhry. "We've never before seen a stem cell type that can be harvested from an adult organ—the placenta—and has the ability to travel through the circulation and not be attacked by the immune system."
Dr. Chaudhry and a team of investigators previously discovered that mouse placental stem cells can help the hearts of mice recover from injury that could otherwise lead to heart failure. They identified a specific type of placental stem cells, called Cdx2 cells, as the most effective in making heart cells regenerate. They discovered this by inducing heart attacks in groups of male mice and then injecting the placental Cdx2 cells isolated from females into their bloodstream. Imaging showed that the mice with Cdx2 stem cell treatments had significant improvement in cardiac function and regeneration of healthy tissue in the heart. The mice without this stem cell therapy went into heart failure and their hearts had no evidence of regeneration.
This team also found that the mouse Cdx2 cells have all the proteins of embryonic stem cells, which are known to generate all organs of the body, but also additional proteins, giving them the ability to travel directly to the injury site, which is something embryonic stem cells cannot do, and the Cdx2 cells appear to avoid the host immune response.
The new grant allows the researchers to build upon this discovery by isolating human Cdx2 cells from human placentas and studying their ability to grow heart cells. They also plan to expand into other organs and tissues in the future.
"This was a serendipitous discovery based on clinical observations of patients with peripartum cardiomyopathy. We surmised that stem cells originating from the placenta may be assisting in repair of the mother's heart and designed studies to identify the cell types involved. We then showed that they work very well in male mice also when isolated from female placentas and now we hope to design a human cell therapy strategy for heart regeneration with this grant. Given that these cells maintain all the 'stem' properties of embryonic stem cells, we are hopeful to utilize them for other types of organ repair as well," adds Dr. Chaudhry.
The grant is being used in collaboration with the Departments of Obstetrics and Gynecology and Pathology at Cedars-Sinai Medical Center in Los Angeles.
