Exosomes Derived From Bone Narrow Mesenchymal Stem Cells Inhibit Apoptosis Of Mice Pulmonary Vascular Endothelial Cells In COPD Via MiR-30b

Objective:(1)To clarify whether bone marrow mesenchymal stem cells(BMSC)derived exosomes can attenuate cigarette smoke extract(CSE)-induced emphysema in mice.(2)To investigate whether BMSC exosomes can alleviate CSE-induced apoptosis of mice pulmonary vascular endothelial cells(PVEC)via miR-30 b.Methods:(1)In vivo study: Mice bone marrow mesenchymal stem cells were isolated by whole bone marrow adherent method.BMSC exosomes were isolated by differential centrifugation.The CSE-induced emphysema mice were treated with exosomes via intratracheal instillation.HE staining was used to evaluate emphysema.The expression of miR-30 b was detected by real-time quantitative polymerase chain reaction(q PCR),and the protein expressions of bcl-2,bax and cleaved caspase-3 were detected by western blot.(2)In vitro study: We isolated mice pulmonary vascular endothelial cells by magnetic-activated cell sorting.PVEC were treated with different CSE concentrations(0,1%,2.5%,4%)for 24 h.The apoptosis rate of PVEC was detected by flow cytometry,and miR-30 b expression was detected by q PCR.We did co-culture of exosomes and PVEC for 24 h,and then treated cells with2.5% CSE for 24 h.The expression of miR-30 b,bcl-2,bax and cleaved caspase-3 were detected.miR-30 b mimic was transfected into PVEC for24 h,and then using 2.5% CSE to intervene PVEC for 24 h.The apoptosis rate of PVEC and the expression of miR-30 b,bcl-2,bax and cleaved caspase-3 were detected.Results:(1)Compared with control group,obvious emphysema changes were observed in lung tissue of mice with intraperitoneal injection of CSE,and the mean linear intercept,alveolar destructive index and cells apoptosis were significantly increased,as well as the expression of miR-30 b in lung tissue was significantly decreased.BMSC exosomes treatment can alleviate CSE-induced emphysema and cells apoptosis in mice(p < 0.05)and up-regulate the expression level of miR-30 b in lung tissue(p < 0.05).(2)When using different concentrations of CSE to intervene PVEC,the cells apoptosis rates gradually increased,while the expression of miR-30 b gradually decreased with the increased of the CSE concentration.BMSC exosomes pretreatment could decrease the expression of bax and cleaved caspase-3,and increase the expression of bcl-2 and up-regulate the expression of miR-30 b in CSE-induced PVEC(p < 0.05).Overexpression of miR-30 b can protect CSE-induced PVEC apoptosis,decrease the expression of bax and cleaved caspase-3,and increase the expression of bcl-2(p < 0.05).Conclusion: Bone marrow mesenchymal stem cells derived exosomes can attenuate mice emphysema.The mechanism may be that miR-30 b reduces CSE-induced apoptosis of pulmonary vascular endothelial cells.Table 6,Graph 11,References 51...