Cardiac regeneration is another stem cell fad

Stem cell–containing products and treatments have recently become an expensive health and beauty trend promising miracle cures and benefits. Stems cells have the ability to develop into other specialized cell types in the body, leading some to think they have regenerative powers. New stem cell-containing skin care products claim to reduce or reverse the aging process, without providing any supporting scientific data. Scientists are rightly skeptical when consumers throw away huge amounts of money on products like these. However, they too have been susceptible to similar false claims about stem cells in the heart.

The big question since the early 2000’s in cardiac regenerative medicine has been, “Does the adult heart contain regenerative stem cells that can be harnessed to repair damaged tissue after a heart attack?” The answer is simple: the adult heart does not contain stem cells. Yet, cardiac stem cells are one of the most debated topics in the field of cardiovascular research.

“The inaccurate and reckless falsified studies have been extremely damaging to the field of heart research...” --Cortney Gensemer

The controversy started when Piero Anversa, previously at Harvard Medical School and Brigham and Women’s Hospital, published an eye-catching paper in Nature, stating that bone marrow stem cells can repair the heart after heart attack. Anversa then went on to publish that cells from the adult heart itself expressing a specific protein, called c-kit, can be harnessed to repair damaged tissue after a heart attack. A number of scientists challenged Anversa’s findings. Irving Weissman at Stanford University and  Charles Murray at the University of Washington in Seattle refuted Anversa’s initial study, showing that bone marrow cells injected into the heart do not become cardiac cells. Additional studies by  by Jeffrey Molkentin, Yan Li, and  Bin Zhoe completely undercut Anversa’s findings,  showing that the adult heart does not contain stem cells.

Eventually, more than 30 papers by Anversa were retracted for containing falsified data, which led to the closure of his lab and a fine against his hospital for fraudulently acquiring federal grant money. Even after the retractions, the push to prove the existence of cardiac stem cells has continued. Scientists are still spending time and grant money investigating the regenerative capabilities of the heart that, before the early 2000’s, we were pretty confident were non-existent. Companies have been formed to investigate new treatments, and clinical trials were based off of the falsified findings.

Much like most of the stem cell products marketed for consumers, cardiac stem cells are a waste of time and money for scientists. The inaccurate and reckless falsified studies have been extremely damaging to the field of heart research, especially to young, naïve scientists wasting years of thesis or postdoctoral research on a fruitless topic. With overwhelming evidence against the existence of stem cells in the heart and the majority of the supporting evidence since retracted, the answer should be obvious. Molkentin said it best: “There are no stem cells in the heart. Quit trying to publish those results.”