The heart contains cells that can divide and mature after birth, which might allow the organ to regenerate itself. This surprise discovery raises the possibility of transplanting these cells into hearts crippled by heart attack to mend the damage.
A heart attack kills off many cells in the heart. These are replaced by scar tissue, made up of connective-tissue cells, called fibroblasts. As a result, parts of the heart become thin and fail to beat properly.
Because fully developed heart cells do not divide, medical experts viewed the organ as unable to regenerate after injury. But Kenneth Chien, of the University of California, San Diego, and his colleagues now challenge this belief.
The researchers searched for ‘cardiac progenitor cells’, which are rare cells from the heart’s early development that retain the ability to reproduce. They looked for cells containing the products of a gene called islet-1, which is expressed in these progenitor cells.