Pim1 maintains telomere length in mouse cardiomyocytes by inhibiting TGFβ signalling.

Aims: Telomere attrition in cardiomyocytes is associated with decreased contractility, cellular senescence, and up-regulation of proapoptotic transcription factors. Pim1 is a cardioprotective kinase that antagonizes the aging phenotype of cardiomyocytes and delays cellular senescence by maintaining telomere length, but the mechanism remains unknown. Another pathway responsible for regulating telomere length is the transforming growth factor beta (TGFβ) signalling pathway where inhibiting TGFβ signalling maintains telomere length.

Hypoxia Prevents Mitochondrial Dysfunction and Senescence in Human c-Kit Cardiac Progenitor Cells.

Senescence-associated dysfunction deleteriously affects biological activities of human c-Kit cardiac progenitor cells (hCPCs), particularly under conditions of in vitro culture. In comparison, preservation of self-renewal and decreases in mitochondrial reactive oxygen species (ROS) are characteristics of murine CPCs in vivo that reside within hypoxic niches. Recapitulating hypoxic niche oxygen tension conditions of ∼1% O in vitro for expansion of hCPCs rather than typical normoxic cell culture conditions (21% O ) could provide significant improvement of functional and biological activities of hCPCs.