Abstract 10791: Regeneration-Associated Cells Derived Exosomes Beneficial Than Mesenchymal Stromal Cells Derived Exosome in the Context of Myocardial Ischemia-Injury

Abstract

Introduction: Vasculogenic conditioning of pro-inflammatory cells such as macrophages type 1, T cells, and primitive EPCs shifted their phenotype to pro-regenerative cells such as vasculogenic EPCs, M2 macrophages, and reg T cells, also known as regeneration-associated cells (RACs). Here, we investigated therapeutic efficacy of RAC-derived extracellular vesicles (RACev) in comparison with MSC-derived EVs (MSCev) in the context of myocardial ischemia-reperfusion injury (IRI). Methods: RACev and MSCev were isolated via ultracentrifugation. EVs quantity and quality were characterized by nanotracking analysis and CD9, CD63, Alix expression. EVs miR was sequenced and regenerative responsible miRs were validated using TargetScan and miRBase. Allogeneic immune response to the RACev and MSCev were evaluated. The function of RACev and MSCev were evaluated using HUVECs proliferation/cell-cycle assays in vitro, and repetitive (30min, d1, and d3 after IRI) systemic infusion with either RACev or MSCev in a myocardial IRI model. Results: Nanotracking analysis showed significant differences in quantity RACev vs. MSC (P= 0.03). In vitro , RACev markedly enhanced cell viability, proliferation, and migration of HUVECs in a dose-dependent manner compared to MSCev. Systemic injection of RACs (5x10 5 ) derived EVs improved cardiac functions such as ejection fraction (P= 0.005) than MSCev treated group. In histology, RACev transplanted group showed less interstitial fibrosis and enhanced capillary densities (P =0.05) compared to MSCev. These beneficial effects are coupled with significant expression of angiogenesis, anti-inflammation, cardiomyogenesis, and anti-fibrosis-related miRs in RACev but not in MSCev. In vivo bioluminescence and labeled EVs histology tracking analyses depicted preferential accumulation of RACev into the IRI myocardium (P=0.01) than MSCev. Immune phenotyping analysis confirmed similar immunomodulatory effects of MSCev and RACev. Conclusion: Repetitive systemic transplantation of RACev is superior to MSCev in terms of cardiac function enhancements via crucial angiogenesis, anti-fibrosis, anti-inflammation, cardiomyogenesis, and anti-apoptosis-related miRs delivery to the ischemic tissue.