Paracrine Effects of the Pluripotent Stem Cell-Derived Cardiac Myocytes Salvage the Injured Myocardium
Rationale: Cardiac myocytes derived from pluripotent stem cells have demonstrated the potential to mitigate damage of the infarcted myocardium and improve left ventricular ejection fraction (LVEF). However, the mechanism underlying the functional benefit is unclear.
Objective:To evaluate whether the transplantation of cardiac lineage differentiated derivatives enhance myocardial viability and restore LVEF more effectively than undifferentiated pluripotent stem cells after a myocardial injury (MI). Herein, we utilize novel multimodality evaluation of human embryonic stem cells (hESCs), hESC-derived cardiac myocytes (hCMs), human induced pluripotent stem cells (iPSCs), and iPSC-derived cardiac myocytes (iCMs) in a murine MI model.
Methods and Results: Permanent ligation of the left anterior descending coronary artery was induced in immunosuppressed mice. Intra-myocardial injection was performed with (1) hESCs (n=9), (2) iPSCs (n=8), (3) hCMs (n=9), (4) iCMs (n=14) and (5) PBS control (n=10). LVEF and myocardial viability, measured by cardiac-MRI and manganese-enhanced MRI (MEMRI), respectively, was significantly improved in hCM- and iCM-treated mice compared to pluripotent stem cell- or control-treated mice. Bioluminescence imaging (BLI) revealed limited cell engraftment in all treated groups, suggesting that the cell secretions may underlie the repair mechanism. To determine the paracrine effects of the transplanted cells, cytokines from supernatants from all groups were assessed in vitro. Gene expression and immunohistochemistry analyses of the murine myocardium demonstrated significant up-regulation of the pro-migratory, pro-angiogenic, and anti-apoptotic targets in groups treated with cardiac lineage cells compared to pluripotent stem cell and control groups.
Conclusions: This study demonstrates that the cardiac phenotype of hCMs and iCMs salvages the injured myocardium more effectively than undifferentiated stem cells through their differential paracrine effects.
- cell therapy
- manganese-enhanced MRI (MEMRI)
- myocardial infarction
- magnetic resonance imaging
- cell transplantation
- Received February 15, 2017.
- Revision received July 20, 2017.
- Accepted July 24, 2017.