Abstract 19265: Hyperoxic Cycling of Human Inducible Pluripotent Derived Cardiomyocytes (hipsc-cms) Augments Transplanted Cell Survival in Rats Subjected to Myocardial Infarction
Introduction: Cardiac regeneration via stem cells following acute myocardial necrosis or apoptosis is a promising therapy. However, low cell survival remains a significant limitation primarily due to the hypoxic microenvironment of the ischemic heart.
Hypothesis: Preconditioning of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) with hyperoxic oxygen cycling will enhance cell resistance to hypoxic stress and improve cell survival upon transplantation into the ischemic heart.
Methods: Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) were subjected to two cycles of hypoxia and reoxygenation as mentioned below. Experiments were performed in three different groups in vitro. 1) HYP (Hypoxia only, 12 h); 2) HP-21 (2 cycles of Hypoxia (15 min) and reoxygenation (21% O2, 30 min) followed by 12 h of continuous hypoxia; and 3) HP-95 (2 cycles of Hypoxia (15 min) and reoxygenation (95% O2, 30 min) followed by 12 h continuous hypoxia. For in vivo studies hiPSC-CMs (red fluorescent protein (rFP) expressing) were subjected to two cycles of hypoxia and reoxygenation as mentioned above. Immediately after the preconditioning treatment the cells were collected for transplantation into the rat heart. The preconditioned hiPSC-CMs were then transplanted into nude athymic rats 30-min after permanent LAD ligation. Confocal imaging was performed to assess the cell survival and engraftment at one-week after MI. Furthermore, western blot analysis was performed to assess the expression levels of p-AKT, VEGF and HIF-1 in oxygen cycling hiPSC-CMs groups, when compared to non-preconditioned groups in vitro.
Results: In vitro studies showed an increased expression of p-AKT and VEGF in HP-21 and HP-95 groups compared to HYP group only. Similarly, in vivo data demonstrated increased engraftment of hiPSC-CMs in HP-21 (1.6-fold) and HP-95 (3.4-fold) groups, when compared with non-preconditioned hiPSC-CMs group.
Conclusions: Overall, our results demonstrated oxygen cycling enhances pro-survival and angiogenesis related proteins in vitro and augments cell engraftment in vivo. Hyperoxic cycling seems to a novel potential option to improve the survival of stem cells following transplantation in the ischemic heart.
Author Disclosures: M. Khan: None. C. Dall: None. C. Chen: None. M. Angelos: None.
- © 2016 by American Heart Association, Inc.