Abstract 14618: Mitochondria-Rich Extracellular Vesicles From Stem Cell-Derived Cardiomyocytes Restore Cardiac Energy Metabolism of Ischemic Myocardium in a Preclinical Pig Model

Abstract

Introduction: Disruption of mitochondrial energy metabolism underlies the pathophysiology of heart failure. We previously demonstrated that intramyocardial injection of mitochondria-rich extracellular vesicles (M-EVs) from iPSC-derived cardiomyocytes (iCMs) transfer mitochondrial and nonmitochondrial substances into the recipient cardiomyocytes, stimulating mitochondrial biogenesis and functional capacities in the murine acute myocardial infarction (MI) model. However, the therapeutic potential and underlying mechanism in larger animal models remain to be assessed. Methods: M-EVs were isolated from the conditioned medium of iCMs via differential ultracentrifugation. Yorkshire pigs were subjected to myocardial ischemia for one hour via balloon occlusion of the left anterior descending artery. 1.0 x 10 11 M-EVs were injected into the infarct border zone using a percutaneous catheter delivery system (Biocardia, Inc). Cardiac functions were analyzed by cardiac MRI. Liquid chromatography-tandem mass spectrometry was performed to investigate comprehensive protein profiles of M-EV content and pig heart tissue samples. Results: Flow cytometric and electron microscopic analysis revealed that mitochondria inside M-EVs retained membrane potentials and structural integrities. M-EV therapy significantly improved left ventricular (LV) ejection fractions (30.5 vs. 21.2 %, p=0.004) and reduced LV end-diastolic volume (119 vs. 192 mL, p=0.047) at week-4 as compared with PBS control. No difference was observed in the scar size. Proteomics analysis identified a total of 37 significantly enriched proteins in M-EVs. Gene Set Enrichment Analysis of the M-EV proteome revealed significantly upregulated biological processes, including oxidative phosphorylation. STRING network analysis identified enriched proteins that directly or indirectly interact with a proliferator-activated receptor γ coactivator-1 α, a master regulator of mitochondrial biogenesis. Conclusion: M-EV-mediated transfer of mitochondria and enriched proteins enhanced cardiac function by restoring energy metabolism in pig acute MI model. M-EV therapy may represent a novel biologic that directly targets energy metabolism in mitochondria-related diseases.