Bioengineers at the University of California, Berkeley in a new study published in Nature say they have identified two key regulatory pathways that control how well adult stem cells repair and replace damaged tissue. They then tweaked how those stem cells reacted to those biochemical signals to revive the ability of muscle tissue in old mice to repair itself nearly as well as the muscle in the mice's much younger counterparts.
Because the findings relate to adult stem cells that reside in existing tissue, this approach to rejuvenating degenerating muscle eliminates the ethical and medical complications associated with transplanting tissues grown from embryonic stem cells.
The researchers focused on the interplay of two competing molecular pathways that control the stem cells, which sit next to the mature, differentiated cells that make up our working body parts. When the mature cells are damaged or wear out, the stem cells are called into action to begin the process of rebuilding.