One approach involves exercising the recipient following regenerative treatment. Young mice that are run on a treadmill following the transplantation of muscle-derived stem cells, for example, developed more new muscle cells and had improved strength than sedentary controls.
Because not everyone is able to undergo such physical exertion, scientists are also testing whether giving cells a mechanical workout in the lab prior to transplantation offers the same kinds of benefits. By stretching mesenchymal stem cells in vitro before injecting them into old mice, researchers have elicited improvements in muscle growth and strength similar to those seen in young mice.
EXERCISING THE MUSCLE EXERCISE THE CELL
(1) Mesenchymal stem cells obtained from hindlimb muscles of young mice
(1) Mesenchymal stem cells obtained from hindlimb muscles of young mice
(2) Mesenchymal stem cells injected into hindlimbs of young mice
(2) Cells mechanically stretched
in the lab
(3) Mice run on treadmill
(3) Cells injected into hindlimb muscles of old mice
(4) Mice develop more muscle stem cells, more large blood vessels, greater myofiber growth, and improved muscle strength than sedentary controls.
(4) Mice end up with more muscle stem cells, more large blood vessels, greater blood flow, and increased muscle strength than mice injected with non-stretched cells. Injection of stretched cells, which release growth and neurotrophic factors into the bloodstream, also spurs greater numbers of immature neurons in the brain, specifically the hippocampus, which may enhance learning and memory.
Illustrations by Kimberly Battista
