Coordination of satellite cell activation and self-renewal by Par-complex-dependent asymmetric activation of p38?/? MAPK.

ABSTRACT: In response to muscle injury, satellite cells activate the p38?/? MAPK pathway to exit quiescence, then proliferate, repair skeletal muscle, and self-renew, replenishing the quiescent satellite cell pool. Although satellite cells are capable of asymmetric division, the mechanisms regulating satellite cell self-renewal are not understood. We found that satellite cells, once activated, enter the cell cycle and a subset undergoes asymmetric division, renewing the satellite cell pool. Asymmetric localization of the Par complex activates p38?/? MAPK in only one daughter cell, inducing MyoD, which permits cell cycle entry and generates a proliferating myoblast. The absence of p38?/? MAPK signaling in the other daughter cell prevents MyoD induction, renewing the quiescent satellite cell. Thus, satellite cells employ a mechanism to generate distinct daughter cells, coupling the Par complex and p38?/? MAPK signaling to link the response to muscle injury with satellite cell self-renewal.

SUBMITTER: Troy A 

PROVIDER: S-EPMC4077199 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature