外泌体介导miR-27a-3p/RGPD6轴改善心肌缺血再灌注损伤OA

Object To explore the effect of exosome-mediated miR-27a-3p/RGPD6 axis on myocardial ischemia-reperfusion injury(MIRI).Methods Bone marrow mesenchymal stem cells(BMMSCs)were isolated from rat bone marrow and transfected with miR-NC,miR-27a-3p mimic,or miR-27a-3p inhibitor,transfection efficiency was then verified.Subsequently,exosomes derived from BMMSCs were isolated and characterized.A myocardial ischemia-reperfusion(I/R)model was established in mice:A total of 36 SPF-grade male mice were randomly divided into six groups(6 cases per group):sham,I/R,BMMSC-derived exosomes,miR-NC,miR-27a-3p mimic,and miR-27a-3p inhibitor groups.Except for the sham group,all other groups underwent 30 min of ischemia to establish the I/R model.Subsequently,the sham and I/R groups were injected with 30 μL of PBS,while the remaining groups received 30 μL of BMMSC-derived exosomes transfected accordingly.Left ventricular function was assessed by ultrasound.Histopathological changes and apoptosis in mouse myocardial tissue were observed using HE staining and TUNEL staining.Serum levels of myocardial injury markers in mice,including cardiac troponin I(cTnI)and creatine kinase-MB(CK-MB),were measured by enzyme-linked immunosorbent assay(ELISA).The relative protein expression of cleaved caspase-3 and RGPD6 was detected by Western blot.In vitro,miR-NC,miR-27a-3p mimic,or miR-27a-3p inhibitor were transfected into human primary cardiomyocytes and characterized.The expression levels of miR-27a-3p and RGPD6 were measured by qPCR.The binding between miR-27a-3p and RGPD6 was determined by dual-luciferase reporter assay.Results Various identification results confirmed the successful isolation of both BMMSCs and exosomes derived from the transfected cells.In vivo,ultrasound results showed that the miR-27a-3p mimic improved left ventricular systolic function.HE staining and TUNEL staining indicated that the miR-27a-3p mimic suppressed myocardial tissue damage and cell apoptosis.ELISA results demonstrated that the miR-27a-3p mimic reduced the expression of myocardial injury markers.Western blot results revealed that the miR-27a-3p mimic decreased the relative expression of cleaved caspase-3 and RGPD6 in myocardial tissue.Conversely,the administration of the miR-27a-3p inhibitor resulted in opposite effects on all the aforementioned indicators.These results were also validated in vitro.Furthermore,the dual-luciferase reporter assay confirmed that miR-27a-3p could target the RGPD6 gene.Conclusion Mesenchymal stem cells exosome-derived miR-27a-3p can target the RGPD6 gene,thereby ameliorating MIRI.