Introduction: Myocardial infarctionrepresents a life-threatening condition. The mechanisms involve the accumulation of reactive oxygen species and hypoxia. Immediate therapeutic intervention of bone marrow derived mesenchymal stem cells (BM-MSCs) and their exosomes have been investigated for their possible therapeutic effects to avoid cardiac remodeling and fibrosis.
Aim of the Work: To investigate the therapeutic potential of BM-MSCs versus their exosomes to influence the isoproterenol (ISO) induced myocardial changes in a rat model.
Materials and Methods: 32 adult male albino rats were divided into five groups: Control group, ISO group ( received ISO in a dose of 85mg/Kg body weight subcutaneously, twice at 24 hours interval, and sacrificed four weeks after the last dose), exosomes and stem cells treated groups (injected via the tail vein by 100μg of exosomes or 1.2 x 106 of BM-MSCs respectively, 24 hours after the last dose of ISO and sacrificed after four weeks) and recovery group (received ISO, left for four weeks after the last dose of ISO, then sacrificed). Samples from the left ventricle were processed for histological assessment using light and electron microscopes. Immunohistochemical assessment of anti-caspase-3 was included. The right ventricles were homogenized for assessment of malondialdehyde, total antioxidant capacity, tumor necrosis factor- alpha and transforming growth factor beta1. Troponin I and creatine kinase were also assessed in the serum.
Results: Histologically, the ISO group revealed degenerative changes in the form of myocytolysis, cellular infiltration and nuclear changes. Serum levels of Troponin I, and Creatine kinasewere significantly increased. Significant increase inthe anti-caspase-3 reaction was demonstrated morphometrically. Both exosome and stem cell groups revealed improvement in different assessed parameters that was more evident in the exosome treated group.
Conclusion: Exosomes proved to demonstrate more potent therapeutic effect as compared to BM-MSCs on isoproterenol induced ventricular myocardium change, thus regarded as a promising therapeutic strategy in myocardial infarction.