RESUMO
Objective:To investigate the trait of exosomes serected by mesenchymal stem cells derived form orofacial bone(OMMSCs-Exo) and the communication between the exosomes and macrophages.Methods:OMMSCs were isolated from orthognathic surgical sites and cultured by limited dilution.Their cell surface markers were characterized by flow cytometry.the rate of colony formation and the differentiation potential of OMMSCs were evaluated.Exosomes were prepaired from the culture supernatants of OMMSCs(P4-P6).Transmission electron microscopy(TEM) and western blot were used to identify the exosomes.The expression of miRNAs associated with immunity such as miR-223 and miR-let-7c were determined by Real-time RT-PCR.Human peripheral blood mononuclear cells(PBMCs) were isolated from health donor and co-cultured with OMMSCs-Exo.After co-cultured for 24 h,the communication between exosomes and macrophages was tested using a confocal microscope.Results:Human OMMSCs were proved to have the characteristics of mesenchymal stem cells.The diameter of OMMSCs-Exo ranged from 40 to 160 nm.The OMMSCs-Exo expressed CD63 and CD81 and contained miRNAs associated with immune regulation such as miR223 and miR-let-7c.OMMSCs-Exo could be uptaken by macrophages.After co-culture of OMMSCs-Exo with marcrophages for 72 h,miR223 expression in macrophages increased.Conclusion:OMMSCs-Exo has the potential of immune regulation.
RESUMO
Objective:To compare the proliferation and osteogenic differentiation between human bone marrow mesenchymal stem cells from orofacial bone(OMMSCs)and those from long bone(BMMSCs).Methods:OMMSCs were isolated from orthognathic surgical sites and cultured by limited dilution.BMMSCs were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method.The surface markers of the cells were detected by flowcytometry.Single-colony formation,CCK assay and cell circle analyses were conducted.Osteogenic differentiation ability was evaluated by ALP activity test and Alizarin red staining after osteogenic induction culture.Results:The cell surface markers STRO-1 and CD105 of both stem cells were positive,CD34,CD31 and CD45 were negative. OMMSCs generated significantly higher numbers of colonies than BMMSCs.In addition,OMMSCs had a higher proliferation rate and more cells in proliferative(S +G2 )stage than BMMSCs.After osteogenic induction for 3,5,7 and 10 d,OMMSCs showed higher levels of ALP activity.OMMSCs formed significantly more mineralized nodules than BMMSCs after 21-day ostogenic induction.Conclusion:The proliferation and osteogenic differentiation capacity of OMMSCs are higher than those of BMMSCs.