Activation of PI3K wakes up the dormant adult muscle stem cells upon muscle injury

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Photo by chris robert on Unsplash

Photo by chris robert on Unsplash

Why is it important?

Adult muscle stem cells (MuSCs) are known to be dormant (or quiescent) in homeostatic uninjured muscles with very little turnover. Upon muscle injury, the dormant MuSCs are activated (or awakened) and go through a prolonged (~36 hours) cell growth phase before re-entering the cell cycle to proliferate, and then differentiate and fuse with each other to repair the damaged muscles. It remains unclear what signal(s) wakes up the dormant MuSCs upon muscle injury. In the current study, we identify PI3K as an indispensable intracellular signalling molecule responsible for "waking up" the dormant MuSCs. Our findings reveal a key mechanism that controls early activation of the dormant MuSCs upon muscle injury.