Repairing (and Building) Muscle With Stem Cells

Your muscles have stem cells too, in case of injury. But muscle stem cells can not only heal muscle injuries, they can build new muscle--if they receive the proper stimulation.

One of the key players in regeneration following injury are muscle stem cells - so called satellite cells. A critical regulator of this process is calcineurin. It is activated by injury and controls the activity of other proteins involved in stem cell differentiation and the overall response to damage.

Nadia Rosenthal, head of EMBL's Mouse Biology Unit, and her team have now found a naturally occurring version of calcineurin, called CnAß1 that is permanently active - it does not depend on whether the person is injured or not.

...The study results To test the effects of permanent CnAß1 expression Enrique Lara-Pezzi from Rosenthal's lab overexpessed CnAß1 in muscle cells, and observed increased proliferation of muscle stem cells. Switching off the protein had the opposite effect; stem cells stopped dividing and differentiated into muscle cells instead. When CnAß1 was overexpressed in the muscles of transgenic mice, the animals were resistant to the destructive effects of muscle injury and regenerated the damage more efficiently.

..."Supplementary CnAß1 also reduces the formation of scars in damaged muscle, helps speed up the resolution of inflammation and protects muscle cells from atrophy [wasting] under starvation," said Rosenthal. "These effects make CnAß1 a promising candidate for new therapeutic approaches against muscle wasting."

Source

For conventional researchers, the injury-healing effect of CnAB1 (calcineurin) is the primary objective. Researchers looking into extreme performance will go further, to find ways to first proliferate more stem cells, then differentiate them into skeletal muscle (and cardiac muscle in the heart) to augment strength and performance. This is inevitable. A pulsed expression of CnAB1 would be one approach--with research needed to identify optimal timing for various types of desired athletic performance.