Exosomes Derived From Human Umbilical Cord Mesenchymal Stem Cells Promote The Proliferation And Migration Of Bone Marrow Stem Cells

Objective: To explore the effect of exosomes derived from human umbilical cord mesenchymal stem cells(hUC-MSCs)on the proliferation and migration of rabbit bone marrow stem cells.Methods: The tissue block adherence method is used to isolate and culture primary human umbilical cord mesenchymal stem cells,which are passaged systematically and cultured with medium replacement.The surface marker antigens of the third generation hUC-MSCs were identified by flow cytometry.HUC-MSCs were cultured for adipogenesis in vitro and then stained with oil red "O",hUC-MSCs were stained with Alizarin Red for osteogenic induction culture in vitro,and Alzine was used for chondrogenic induction culture of hUC-MSCs in vitro Blue staining to complete the identification of three-way differentiation;ultracentrifugation was used to separate and extract the exosomes derived from hUC-MSCs,and they were identified by transmission electron microscopy observation,exosomal concentration and particle size(NTA)detection,and Western Blot detection.CCK-Method 8 was used to determine the effect of hUC-MSCs-derived exosomes in promoting the proliferation of rabbit bone marrow stem cells,and the scratch test was used to determine the effect of hUC-MSCs-derived exosomes in promoting the migration of rabbit bone marrow stem cells.Results: 1.The cells separated and obtained by the adherence method of the tissue block were observed under an inverted microscope and showed stem cell-like adherent growth,which was a slender spindle shape.CD73,CD90,and CD105 were all positively expressed by flow cytometry.In vitro staining results for the induction of adipogenesis,osteogenesis,and cartilage were all positive.The NTA of exosomes derived from hUC-MSCs extracted by ultracentrifugation showed that their size was 50-200 nm,mainly at 115 nm.Western blot results showed that hUC-MSCs exosomes express specific exosomal surface proteins CD9,CD63,and TSG101.2.Experimental results detected by CCK-8 method.Compared with the blank group,the experimental group did not significantly promote the proliferation of rabbit bone marrow stem cells..3.Scratch experiment observes that human umbilical cord mesenchymal stem cell exosomes can significantly promote the healing of rabbit bone marrow stem cell scratches,and as the concentration of exosomes increases and the duration of action increases,the healing speed is significantly accelerated.Conclusions : 1.The hUC-MSCs were successfully sorted from human umbilical cord tissue by the tissue block attachment method.The three-line induced differentiation staining results were positive,and the sorted hUC-MSCs had multiple differentiation potentials.2.The results of transmission electron microscopy observation,exosomal concentration and particle size(NTA)detection,Western Blot detection for identification,etc.can confirm that the vesicles isolated and extracted by ultracentrifugation are hUC-MSCs exosomes.3.Human umbilical cord mesenchymal stem cell exosomes at various concentrations currently set have no significant effect on the proliferation of rabbit bone marrow stem cells.4.Exosomes derived from human umbilical cord mesenchymal stem cells can promote the migration of rabbit bone marrow stem cells,and there is a dose and time dependence.Provide a certain experimental basis for the clinical research and application of hUC-MSCs exosomes in tissue engineering.