Intramyocardial injection of hypoxia-conditioned extracellular vesicles modulates apoptotic signaling in chronically ischemic myocardium

Dwight D Harris; Sharif A Sabe; Mohamed Sabra; Cynthia M Xu; Akshay Malhotra; Mark Broadwin; Debolina Banerjee; M Ruhul Abid; Frank W Sellke

doi:10.1016/j.xjon.2023.05.013

Intramyocardial injection of hypoxia-conditioned extracellular vesicles modulates apoptotic signaling in chronically ischemic myocardium

JTCVS Open. 2023 Jun 20:15:220-228. doi: 10.1016/j.xjon.2023.05.013. eCollection 2023 Sep.

Authors

Dwight D Harris¹, Sharif A Sabe¹, Mohamed Sabra¹, Cynthia M Xu¹, Akshay Malhotra¹, Mark Broadwin¹, Debolina Banerjee¹, M Ruhul Abid¹, Frank W Sellke¹

Affiliation

¹ Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI.

Abstract

Objective: Limited treatments exist for nonoperative chronic coronary artery disease. Previously, our laboratory has investigated extracellular vesicle (EV) therapy as a potential treatment for chronic coronary artery disease using a swine model and demonstrated improved cardiac function in swine treated with intramyocardial EV injection. Here, we seek to investigate the potential cardiac benefits of EVs by using hypoxia-conditioned EVs (HEV). Specifically, this study aims to investigate the effect of HEV on apoptosis in chronically ischemic myocardium in swine.

Methods: Fourteen Yorkshire swine underwent placement of an ameroid constrictor on the left circumflex artery. Two weeks later, swine underwent redo left thoracotomy with injection of either saline (control, n = 7) or HEVs (n = 7). After 5 weeks, swine were euthanized for tissue collection. Terminal deoxynucleotidyl transferase dUTP nick end labeling was used to quantify apoptosis. Immunoblotting was used for protein quantification.

Results: Terminal deoxynucleotidyl transferase dUTP nick end labeling staining showed a decrease in apoptosis in the HEV group compared with the control (P = .049). The HEV group exhibited a significant increase in the anti-apoptotic signaling molecule phospho-BAD (P = .005), a significant decrease in B-cell lymphoma 2 (P = .006) and an increase in the phospho-B-cell lymphoma to B-cell lymphoma 2 ratio (P < .001). Furthermore, the HEV group exhibited increased levels of prosurvival signaling markers including phosphoinositide 3-kinase, phosphor-extracellular signal-regulated kinase 1/2, phospho-forkhead box protein O1, and phospho-protein kinase B to protein kinase B ratio (all P < .05).

Conclusions: In chronic myocardial ischemia, treatment with HEV results in a decrease in overall apoptosis, possibly through the activation of both pro-survival and anti-apoptotic signaling pathways.

Keywords: apoptosis; chronic coronary artery disease; chronic myocardial ischemia; extracellular vesicle; hypoxia-conditioned; swine.

Abstract

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