Muscle gets stressed? p53 represses and protects

Long-living tissues, such as skeletal muscles and neurons, are composed of terminally differentiated cells that irreversibly withdraw the cell cycle and therefore do not have the opportunity to cyclically monitor the integrity of their genome, by means of cell cycle checkpoints, as dividing cells do.1 Moreover, terminally differentiated cells have an impaired DNA-repair machinery2 and are typically resistant to apoptosis3—an intrinsic trade-off that preserves survival of these tissues throughout the lifespan, at the expense of their nuclear turnover. Thus, the genomic stability of post-mitotic tissues is highly dependent on the accuracy by which progenitor cells protect the integrity of their genome before differentiating.