Source: European Society of Cardiology
Date: 23 May 2012
Summary:
For the first time scientists have succeeded in taking skin cells from heart failure patients and reprogramming them to transform into healthy, new heart muscle cells that are capable of integrating with existing heart tissue. The research, which is published online Wednesday in the European Heart Journal [1], opens up the prospect of treating heart failure patients with their own, human-induced pluripotent stem cells (hiPSCs) to repair their damaged hearts. As the reprogrammed cells would be derived from the patients themselves, this could avoid the problem of the patients’ immune systems rejecting the cells as “foreign”. However, the researchers warn that there are a number of obstacles to overcome before it would be possible to use hiPSCs in humans in this way, and it could take at least five to ten years before clinical trials could start.
The researchers took skin cells from two male heart failure patients (aged 51 and 61) and reprogrammed them by delivering three genes or “transcription factors” (Sox2, Klf4 and Oct4), followed by a small molecule called valproic acid, to the cell nucleus. Crucially, this reprogramming cocktail did not include a transcription factor called c-Myc, which has been used for creating stem cells but which is a known cancer-causing gene.
The researchers also used an alternative strategy that involved a virus that delivered reprogramming information to the cell nucleus but which was capable of being removed afterwards so as to avoid insertional oncogenesis. The resulting hiPSCs were able to differentiate to become heart muscle cells (cardiomyocytes) just as effectively as hiPSCs that had been developed from healthy, young volunteers who acted as controls for this study. Then the researchers were able to make the cardiomyocytes develop into heart muscle tissue, which they cultured together with pre-existing cardiac tissue. Within 24-48 hours the tissues were beating together.
