Cardiac stem cells in the post-Anversa era

Extract

At the turn of the century, prevailing dogma stated that the adult mammalian heart was incapable of self-repair. Postnatal growth reflected increases in cardiomyocyte size alone rather than through increases in cell number. This dogma was shaken by the demonstration that bone marrow cells could be used to regenerate heart muscle. The subsequent discovery that adult hearts contained cells that expressed the haematological stem cell marker c-Kit led to a large body of literature, mostly from Piero Aversa’s laboratory, which advanced the premise that cardiac c-Kit+ cells were clonogenic, multipotent, and capable of self-renewal (i.e. genuine heart stem cells). While this hypothesis was popularized and espoused by many, the validity of Anversa’s findings were questioned early on by several investigators who failed to reproduce key findings.^1,2

On 14 October 2018, the Harvard Medical School and Brigham and Women’s Hospital brought an end to this chapter as 31 papers from the lab pioneering heart c-Kit+ cells were recommended for retraction because the validity of the scientific data was uncertain. While the full identity of the papers affected is still unknown, the New England Journal of Medicine promptly issued an expression of concern that the data presented in two (heretofore) landmark papers in cardiac regeneration may not be reliable³ and outright retracted a 2011 paper demonstrating evidence for human lung c-Kit+ stem cells.⁴