A Preliminary Study On The Effect Of Exosomes Derived From Mesenchymal Stem Cells On The Senescence Of Bone Marrow Mesenchymal Stem Cells In Vitro

Aging is the process of degenerative changes in organisms.It is an important factor that causes many kinds of chronic diseases.Cellular senescence is related to individual senescence.Cellular senescence is a permanent arrest of cell proliferation cycle and regards as a key factor in individual senescence.Stem cell senescence hinders the process of tissue repair and the application of tissue repair engineering.The main factors that cause stem cell senescence include DNA damage,telomere shortening and mitochondrial damage.Bone marrow mesenchymal stem cells(BMSCs)are used as a kind of seed cells widely used in the treatment of various age-related diseases.However,after long-term culture in vitro,BMSCs will exhibit replicative senescence.When the occurrence of replicative senescence disrupts its function,the quantity and quality of BMSCs are severely intervened.Currently,the way to delay stem cell aging is mainly through reducing the stimulation of stem cells and using drugs to relieve the aging process.It is worth noting that the micro-environment of stem cells has a very important influence on the function of stem cells,and exosomes serve as important media for cell microenvironment.It is important to regulate the aging microenvironment.In this paper,the exosomes derived from young bone marrow mesenchymal stem cells(MSCs)were used to regulate the aging bone marrow mesenchymal stem cells(MSCs),and we explore its effect on the function of MSCs.The main results are as follows:1.After a long period of expansion in vitro,MSCs exhibit senescent phenotype such as morphological flattening,slower proliferation rate,and decreased function.2.Exosomes derived from MSCs improved the senescence of MSCs,and Exosomes derived from MSCs had a significantly lower expression level of ?-galactosidase than Exosomes derived from UCMSCs.Exosomes decreased the expression of p16,p53 and?-H2 AX senescence-associated proteins in MSCs.3.Exosomes derived from MSCs can promote the proliferation of MSCs.4.Exosomes derived from MSCs can increase osteogenic differentiation and adipogenic differentiation of MSCs.5.Exosomes derived from MSCs can improve the microenvironment of MSCs,increase the activity of S D and decrease the level of MDA.Therefore,the exosomes derived from young bone marrow mesenchymal stem cells can help relieve the phenomenon of replicative senescence of BMMSCs in vitro.Exosomes can improve the proliferation and differentiation of aged bone marrow mesenchymal stem cells,which is beneficial to the clinical application of stem cells.