Abstract 14799: Over-expression of Telomerase Reverse Transcriptase Increases Self-renewal, Survival and Multi-potency in Human Cardiac Progenitor Cells Derived From Aged and Diseased Hearts
Introduction: Stem cells, or their derivatives, are an exciting potential treatment for heart failure. We have recently characterised a resident cardiac progenitor cell population, named cardiac colony-forming unit fibroblasts (c-CFU-Fs), and have documented prolonged self-renewal, clonogenicity and multipotent potential within this population. Understanding the role of ageing and disease in this progenitor population can lead to novel methods to enhance their function in future clinical translation.
Aim: To investigate the effects of ageing and disease on c-CFU-Fs and the effects of human telomerase reverse transcriptase (hTERT) over-expression as a novel method to enhance their stem cell properties.
Methods and Results: Human c-CFU-Fs were isolated from non-diseased young (2-10yrs), old (54-64yrs) and diseased (54-64yrs) cardiac samples (N=4 patients/group) by explant culture and purified by FACS sorting. Over-expression of hTERT maintained telomerase activity and increased telomere length (1.5-fold vs non-transduced). Long term self-renewal of c-CFU-Fs in all groups (>2 months) was demonstrated by growth curve analysis of serial passaging. However, significantly reduced self-renewal was seen in c-CFU-Fs from aged hearts. Interestingly, this was rescued with hTERT over-expression where hTERT+ cells displayed extended self-renewal capacity to >8 months. Colony-forming assays showed significantly higher number of colonies in the hTERT+ cells. Greater cell cycle activity was seen in hTERT+ cells compared to non-transduced cells as assessed by Ki67 and BrdU positivity (both, 2-fold increased). hTERT over-expression rescued c-CFU-Fs from starvation-induced apoptosis in young and old hearts by 50% and 60%, respectively. hTERT over-expression significantly enhanced endothelial cell differentiation (CD31+) and formation of cardiomyocyte-like cells (cTnT+, α-actinin+) in in-vitro differentiation assays.
Conclusion: hTERT over-expression in c-CFU-Fs derived from aged and diseased hearts rejuvenates their stem-cell properties and recapitulates the phenotype of c-CFU-Fs derived from young hearts. This represents a novel method for enhancement of cardiac stem cells that could enhance strategies for clinical translation.
Author Disclosures: T.Y. Le: None. H.A. Pickett: None. M. Farraha: None. C. dos Remedios: None. J.J. Chong: None.
- © 2016 by American Heart Association, Inc.