Heart Patches Grown from Old Cells

A new method of growing cardiac tissue is teaching old stem cells new tricks. The discovery, which transforms aged stem cells into cells that function like much younger ones, may one day enable scientists to grow cardiac patches for damaged or diseased hearts from a patient's own stem cells—no matter what age the patient—while avoiding the threat of rejection. Ren-Ke Li,, from the University of Toronto (Canada), and colleagues created the conditions for a 'fountain of youth' reaction within a tissue culture. The team first created a "micro-environment" that allows heart tissue to grow, after which they infused the resulting cell cultures with a combination of growth factors—common factors that cause blood vessel growth and cell proliferation—positioned in such a way within the porous scaffolding that the cells are able to be stimulated by these factors.  Tracking the molecular changes in the tissue patch cells, the researchers observed that certain aging factors were “turned off” -- citing the levels of two molecules in particular, p16 and RGN, which effectively turned back the clock in the cells, returning them to robust and healthy states.