A New Study Found that Cardiac Stem Cells Don’t Exist

At a certain point in time, scientists believed that there are specific stem cells that are found in particular sites in the body. One kind of stem cell that was believed to be a great one is the existence of cardiac stem cells.
A study revealed that the stem cells that were found in some mice’s hearts did not regenerate new tissue after numerous clinical trials. There is also a belief that spawned that the so-called cardiac stem cells are unable to generate new cardiomyocytes- leaving us to believe that regenerating heart tissue is not possible through the use of stem cells.

How the Research Came to Be?

The first ever notion that cardiac stem cells can be derived from humans was back in the early 2000s. Researchers at that time derived stem cells from the bone marrow and from a patient’s adult heart. The C-kit that was found in the cells are believed to regenerate lost and damaged heart tissue given the proper conditions.
The idea was already criticized right from the start. According to Jeffery Molkentin, a cardiovascular biologist at the Cincinnati Children’s Hospital, he said that the idea is not going to be a fruitful one, mainly because the heart tissues do not regenerate after a heart attack. That has been proven countless times already.
There was also a study done back in 2004 that refuted the claim, stating that the bone marrow stem cells that were derived from the patients who suffered a heart attack didn’t reproduce cardiomyocytes at all.

Old Research Revisited

Molkentin and his colleagues’ study was flawed, at least according to a team of researchers. The use of fluorescent markers could have potentially killed the c-kit expressing cells’ ability to create a gene necessary to express the c-kit protein, which may have led to the impairment of the progenitors’ restorative and regenerative abilities.
Since then, Molkentin along with the same team conducted a new study, but this time, they’ve tried a different approach. They now want to examine, in further detail, the endogenous stem cell populations in mice.
Instead of their old tagging techniques, the team employed a new strategy that would label newly generated muscle cells from nonmyocytes through fluorescence. This would allow the researcher to look at all of the stem cells as a whole, as opposed to just looking into specific c-kit cells.
The follow-up experiments told the story that even though nonmyocytes are able to generate new myocytes in the mice embryos, it was not able to generate new muscle cells that are needed to repair an adult mouse’s heart.


Philip Yang, a cardiologist at Stanford University, said that although stem cells are not able to regenerate damaged cardiomyocytes, he believes that progenitor cells may secrete molecules known as paracrine factors that may help repair the damaged heart cells.
Only time will tell if Yang’s approach would lead to something tangible and perhaps, we may finally be able to heal a damaged heart.