Objective: To investigate the effects of exosomes derived from miR-486 gene-modified umbilical cord mesenchymal stem cells (UC-MSCs) on biological characteristics of rat cardiomyocytes.
Methods: The human umbilical cord mesenchymal stem cells (UC-MSCs) were isolated and cultured, then the immunophenotypes and ability of osteogenic and adipogenic differentiation of UC-MSC were identified. The structure of exosomes was observed by electron microscopy; the effect of exosomes on cell migration was detected by transwell cell migration test; the miR-486 high expression of UC-MSC was mediated by using recombinant adenovirus vector, moreover the UC-MSC with high expression of miR-486 were identified by qPT-PCR. The exosomes were isolated from cell culture supernatant by ultracentrifugation and the miR-486 expression level of UC MSC exosomes was detected by qRT-PCR. The effect of exosomes on the proliferation of cardiomyocytes was evaluated by Dye670 marking. The H2O2-induced cardiomyocyte apoptosis model was established, and the effect of exosomes on apoptosis of cardiomyocytes was detected by flow cytometry with Annexin V/PI double staining.
Results: The exosomes derived from UC-MSCs had the diameter between 40-100 nm and double membrane stracture. The recombinant adenovirus could effectively mediate the expression of miR-486 in UC-MSC, and the expression level of miR-486 in exosomes of miR-486-modified UC-MSC significantly increased. The exosomes with miR-486 high expression possessed the pro-proliferation and pro-migration effects on cardiomyocytes, moreover the preventive effect on apoptosis of cardiomyocytes.
Conclusion: The exosomes derived from UC-MSC and accompamied by high expression of miR-486 can promote the proliferation and migration of cardio myocytes, yet can prevent the apoptosis of cardiomyocytes.