Postnatal telomere dysfunction induces cardiomyocyte cell-cycle arrest through p21 activation.

ABSTRACT: The molecular mechanisms that drive mammalian cardiomyocytes out of the cell cycle soon after birth remain largely unknown. Here, we identify telomere dysfunction as a critical physiological signal for cardiomyocyte cell-cycle arrest. We show that telomerase activity and cardiomyocyte telomere length decrease sharply in wild-type mouse hearts after birth, resulting in cardiomyocytes with dysfunctional telomeres and anaphase bridges and positive for the cell-cycle arrest protein p21. We further show that premature telomere dysfunction pushes cardiomyocytes out of the cell cycle. Cardiomyocytes from telomerase-deficient mice with dysfunctional telomeres (G3 Terc(-/-)) show precocious development of anaphase-bridge formation, p21 up-regulation, and binucleation. In line with these findings, the cardiomyocyte proliferative response after cardiac injury was lost in G3 Terc(-/-) newborns but rescued in G3 Terc(-/-)/p21(-/-) mice. These results reveal telomere dysfunction as a crucial signal for cardiomyocyte cell-cycle arrest after birth and suggest interventions to augment the regeneration capacity of mammalian hearts.

SUBMITTER: Aix E 

PROVIDER: S-EPMC4896054 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature