Abstract 16452: Targeting Notch3 Pathway and Using Extracellular Vesicles From Induced Pluripotent Stem Cell-Derived Cardiomyocytes is Effective in Porcine Chronic Myocardial Injury Model

Introduction: Heart failure is the leading cause of hospital admission in the modern U.S. We previously demonstrated that exosomes (Ex) from iPSC-derived cardiomyocytes (iCMs) significantly restored murine peri-infarct region. We found that miR20/92/363 (CORE miRNA) activated iCM proliferation and myocardial restoration by repressing the Notch3 pathway. However, the optimal pre-clinical method to target the Notch3 pathway through Ex, miRNA, and siRNA remains to be assessed. Hypothesis: Exosomes are the most effective biologic for chronic porcine heart failure model. Methods: iPSCs were generated from four heart failure patients (Pt 1-4) and differentiated into iCMs. Ex were isolated from the iCM culture media and used to treat iCMs subjected to hypoxia-injury. The in vitro findings were then confirmed in vivo in Yorkshire pigs subjected to myocardial ischemia-reperfusion injury for one hour via balloon occlusion of the left descending artery. One month later, chronic heart failure model was developed, and percutaneous catheter system (Biocardia, Inc) delivered 10 11 Ex, 4200 μg of CORE miRNA, or 4200 μg of siNotch3 into porcine peri-infarct region. MRI and mRNA seq analyzed the porcine myocardium. Results: Viability of hypoxia-injured iCMs treated by siNotch3 (132.50% viability ± 23.54% SD)*, CORE miRNA (127.79% ± 10.06%)*, Pt 1 Ex (74.88% ± 3.11%)*, Pt 2 Ex (72.90% ± 4.50%)*, Pt 3 Ex (79.11% ± 7.23%)*, and Pt 4 Ex (77.81% ± 3.31%)* all significantly improved iCM viability compared to non-treated hypoxia-injured iCMs (26.09% ± 10.75%, *p<0.05). In porcine chronic heart failure model (n=4 - 6/treatment group), the mean absolute change in LVEF of PBS (control), siNotch3, CORE miRNA, and Pt 1 Ex treatments were -3.55 ± 3.27, 1.19 ± 3.17*, 2.34 ± 1.53*, and 3.53 ± 3.59*, respectively (*p<0.05). mRNA seq, gene ontology, and KEGG analysis of porcine myocardium suggested that myocardial repair occurred through the TGFβ pathway and cell cycle re-entry of cardiomyocytes. Conclusion: siRNA, miRNA, and exosomes are all effective methods to repair the porcine myocardium after chronic myocardial injury. Exosome showed the highest functional restoration. Determination of mechanism and optimal biologic and dose are underway.