Calcium & muscle stem cell activation

Our daily life creates many tiny muscular injuries that usually remain unnoticed because of the strong regenerative power of muscles. Muscle regeneration depends on both the activation of muscle stem cells and their migration at the injury site. Calcium signals are known to influence the genesis of muscles, but their exact role remains unknown.

Calcium triggers migration, but not activation of muscle stem cells

In a recent study published in Cells, scientists from Prof. Maud Frieden’s group shed light on the role of calcium signals in the activation and migration of muscle stem cells. Using an in vitro model, they found that the calcium signals developed by cells after an exposition to a stimulating culture medium are highly heterogeneous. Intrigued by these large variations, they reversed the question and blocked the calcium signals. Researchers thus revealed that inhibiting calcium signals does not prevent muscle stem cell activation but slows down their migration (as visible in the movie on the top).

Muscle stem cells migrate more slowly when calcium signals are inhibited (top) in comparison to standard conditions (bottom). © from Supplementary Materials in Tollance et al. 2022.

What’s next?

These in vitro experiments suggest that the first step of muscle stem cell activation does not depend on calcium and that other mechanisms should play the role of the first trigger. The scientists aim now to lighten on these other mechanisms to deepen their understanding of muscle regeneration.

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