Bmi1 Is Expressed in Postnatal Myogenic Satellite Cells, Controls Their Maintenance and Plays an Essential Role in Repeated Muscle Regeneration

نویسندگان

  • Lesley G. Robson
  • Valentina Di Foggia
  • Aleksandar Radunovic
  • Katy Bird
  • Xinyu Zhang
  • Silvia Marino
چکیده

Satellite cells are the resident stem cell population of the adult mammalian skeletal muscle and they play a crucial role in its homeostasis and in its regenerative capacity after injury. We show here that the Polycomb group (PcG) gene Bmi1 is expressed in both the Pax7 positive (+)/Myf5 negative (-) stem cell population as well as the Pax7+/Myf5+ committed myogenic progenitor population. Depletion of Pax7+/Myf5- satellite cells with reciprocal increase in Pax7+/Myf5+ as well as MyoD positive (+) cells is seen in Bmi1-/- mice leading to reduced postnatal muscle fiber size and impaired regeneration upon injury. Bmi1-/- satellite cells have a reduced proliferative capacity and fail to re-enter the cell cycle when stimulated by high serum conditions in vitro, in keeping with a cell intrinsic defect. Thus, both the in vivo and in vitro results suggest that Bmi1 plays a crucial role in the maintenance of the stem cell pool in postnatal skeletal muscle and is essential for efficient muscle regeneration after injury especially after repeated muscle injury.

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عنوان ژورنال:

دوره 6  شماره 

صفحات  -

تاریخ انتشار 2011