ABSTRACT
Background: Embryonic stem cells (ES) have a great potential for cell-based therapies in a regenerative medicine. However, the ethical and safety issues limit its clinical application. ES-derived extracellular vesicles (ES-EVs) have been reported suppress cellular senescence. Mesenchymal stem cells (MSCs) are widely used for clinical cell therapy. In this study, we investigated the beneficial effects of ES-EVs on aging MSCs to further enhancing their therapeutic effects. Methods:In vitro, we explored the rejuvenating effects of ES-EVs on senescent MSCs by senescence-associated ß-gal (SA-ß-gal) staining, immunostaining, and DNA damage foci analysis. The therapeutic effect of senescent MSC pre-treated with ES-EVs was also evaluated by using mouse cutaneous wound model. Results: We found that ES-EVs significantly rejuvenated the senescent MSCs in vitro and improve the therapeutic effects of MSCs in a mouse cutaneous wound model. In addition, we also identified that the IGF1/PI3K/AKT pathway mediated the antisenescence effects of ES-EVs on MSCs. Conclusions: Our results suggested that ES cells derived-extracellular vesicles possess the antisenescence properties, which significantly rejuvenate the senescent MSCs and enhance the therapeutic effects of MSCs. This strategy might emerge as a novel therapeutic strategy for MSCs clinical application.
Subject(s)
Embryonic Stem Cells/chemistry , Extracellular Vesicles/chemistry , Mesenchymal Stem Cell Transplantation , Wounds and Injuries/therapy , Animals , Cell- and Tissue-Based Therapy , Cellular Senescence , Disease Models, Animal , Embryonic Stem Cells/metabolism , Extracellular Vesicles/metabolism , Humans , Insulin-Like Growth Factor I/metabolism , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Mice , Mice, Inbred BALB C , Phosphatidylinositol 3-Kinases/metabolism , Wounds and Injuries/metabolism , Wounds and Injuries/physiopathologyABSTRACT
BACKGROUND: Multipotent mesenchymal stromal cell (MSC) therapy has been widely recognized as a feasible strategy for regenerating injured myocardial tissue. However, little is known about the efficacy of intravenous injection of allogeneic umbilical cord (UC) MSCs in preclinical models of porcine myocardial infarction. METHODS: Different dosages of allogeneic UC-MSCs or the vehicle [phosphate-buffered saline (PBS)] were delivered intravenously into an acute myocardial infarction (AMI) porcine model twice after coronary ligation. Echocardiography was performed to examine the cardiac function and single photon emission computed tomography (SPECT) and positron emission tomography (PET)/computed tomography (CT) was performed to detect cardiac perfusion and nonviable myocardium. At the end of the experiment, 2,3,5-triphenyl-tetrazolium chloride (TTC) staining and Masson T staining were performed to determine the infarct area. The protein and gene expression levels associated with cardiac function, inflammation, and angiogenesis were examined by Western blot and real time polymerase chain reaction (PCR). In vivo trafficking of intravenous injection of allogeneic UC-MSCs enhanced green fluorescent protein (eGFP) was detected by real time PCR and immunofluorescence. RESULTS: After systemic delivery, allogeneic UC-MSCs were largely distributed in the lungs and some in the infracted myocardium. At week 8 following AMI, echocardiography demonstrated significantly improved fractional shortening in the high-dose (1.5 × 106 cells/kg) group. SPECT-PET/CT showed that UC-MSC treatment in both high and low doses markedly ameliorated the left ventricle (LV) infarct area but did not significantly improve the myocardial perfusion defect. LV remodeling was inhibited by UC-MSC therapy, as reflected by a marked reduction in rthe fibrosis area at basal, middle, and apical levels and reduced extracellular matrix deposition in the total myocardial area. Inflammatory biomarkers (tumor necrosis factor alpha and interleukin-6) were reduced and pro-angiogenesis factors (vascular endothelial growth factor and platelet/endothelial cell adhesion molecule 1) were augmented in the myocardial infarct and border area. High-dose UC-MSCs increased the connexin 43 (Cx43) (myocardium preservation) expression in remote area of the LV myocardium after AMI. CONCLUSIONS: Intravenous injection of UC-MSCs is a feasible and effective way to preserve LV function and ameliorate myocardial remodeling in porcine AMI. The cardioprotective effects of UC-MSCs were attributed to paracrine factors that appear to augment angiogenesis, limit inflammation, and preserve Cx43 gap junction.
