Mitochondria-Rich Extracellular Vesicles From Autologous Stem Cell-Derived Cardiomyocytes Restore Energetics of Ischemic Myocardium

J Am Coll Cardiol. 2021 Mar 2;77(8):1073-1088. doi: 10.1016/j.jacc.2020.12.060.

Abstract

Background: Mitochondrial dysfunction results in an imbalance between energy supply and demand in a failing heart. An innovative therapy that targets the intracellular bioenergetics directly through mitochondria transfer may be necessary.

Objectives: The purpose of this study was to establish a preclinical proof-of-concept that extracellular vesicle (EV)-mediated transfer of autologous mitochondria and their related energy source enhance cardiac function through restoration of myocardial bioenergetics.

Methods: Human-induced pluripotent stem cell-derived cardiomyocytes (iCMs) were employed. iCM-conditioned medium was ultracentrifuged to collect mitochondria-rich EVs (M-EVs). Therapeutic effects of M-EVs were investigated using in vivo murine myocardial infarction (MI) model.

Results: Electron microscopy revealed healthy-shaped mitochondria inside M-EVs. Confocal microscopy showed that M-EV-derived mitochondria were transferred into the recipient iCMs and fused with their endogenous mitochondrial networks. Treatment with 1.0 × 108/ml M-EVs significantly restored the intracellular adenosine triphosphate production and improved contractile profiles of hypoxia-injured iCMs as early as 3 h after treatment. In contrast, isolated mitochondria that contained 300× more mitochondrial proteins than 1.0 × 108/ml M-EVs showed no effect after 24 h. M-EVs contained mitochondrial biogenesis-related messenger ribonucleic acids, including proliferator-activated receptor γ coactivator-1α, which on transfer activated mitochondrial biogenesis in the recipient iCMs at 24 h after treatment. Finally, intramyocardial injection of 1.0 × 108 M-EVs demonstrated significantly improved post-MI cardiac function through restoration of bioenergetics and mitochondrial biogenesis.

Conclusions: M-EVs facilitated immediate transfer of their mitochondrial and nonmitochondrial cargos, contributing to improved intracellular energetics in vitro. Intramyocardial injection of M-EVs enhanced post-MI cardiac function in vivo. This therapy can be developed as a novel, precision therapeutic for mitochondria-related diseases including heart failure.

Keywords: bioenergetics; heart failure; human stem cells; mitochondria; myocardial infarction.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Disease Models, Animal
  • Energy Metabolism
  • Extracellular Vesicles / transplantation*
  • Humans
  • Induced Pluripotent Stem Cells / transplantation*
  • Mice
  • Mitochondria / transplantation*
  • Myocardial Contraction
  • Myocardial Reperfusion Injury / therapy*
  • Myocytes, Cardiac / transplantation*
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • Proof of Concept Study
  • Receptors, Estrogen / metabolism

Substances

  • Esrrg protein, mouse
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Ppargc1a protein, mouse
  • Receptors, Estrogen
  • Adenosine Triphosphate