Stem Cells on Alert: Priming Quiescent Stem Cells After Remote Injury

Rodgers et al. (2014) identified a novel phase of stem cell quiescence called GAlert, which primes stem cells for activation in response to injury-induced signals, even in cells located far from the injury site. This state, dependent on mTORC1 activity, allows cells to enter the cell cycle more quickly than traditional quiescent cells. GAlert cells exhibit higher ATP content and mitochondrial activity. The study demonstrated that GAlert cells enhance muscle regeneration and that this response is not limited to muscle injury but also occurs in other tissues. The findings suggest that mTORC1 signaling is crucial for this priming response, potentially involving a circulating factor that activates mTORC1 in distant stem cells.