Promotion Of Osteoblastic Differentiation Of ADSCs By ADSCs-derived Exosomes Through Activating The Wnt/?-catenin Signaling Pathway

Objective:To investigate the effects of exosomes secreted by adipose-derived stem cells(ADSCs-EXO)on the osteogenic differentiation of adipose-derived stem cells(ADSCs),we compared the activities of Alkaline phosphatase(ALP),the number of mineral nodes as well as the expression of ?-catenin in Wnt/?-catenin signaling pathway before and after inhibiting.Our objective is to explore how ADSCs-EXO interacts with the Wnt/?-catenin signaling pathway to promote the osteogenic differentiation of ADSCs.Methods:In this study,ADSCs were extracted by liposuction,identified and cultured to the third generation(P3)and induced to osteoblasts.The supernatant was collected and ADSCs-EXOs were extracted by ultracentrifugation.Based on different purposes,they were divided into the following four groups: a: N-control group: ADSCs+ normal medium b: Experimental group: ADSCs+ normal medium+ ADSCs-EXO c: Positive control: ADSCs+ osteogenic induction medium d: Inhibitor group: ADSCs+ normal medium+ ADSCs-EXO+ 100 ng/ml DKK1.Alkaline phosphatase(ALP)levels,the number of mineral nodes were measured in each group.The levels of ?-catenin were detected by Western Blot.Results: 1.ALP activity: In the process of osteogenic induction of ADSCs,the ALP activity of Experimental group was significantly increased when treated with 15?g/ml ADSCs-EXO for 12 days(P <0.05).When DKK1 was added at the same time,the activity of ALP was lower than that of Experimental group at 12 th day.2.Number of mineral nodes: In the process of osteogenic induction of ADSCs,the number of mineral nodes of Experimental group was significantly increased when treated with 15?g/ml ADSCs-EXO for 21 days(P<0.05),which is obviously high,compared with that of the Inhibitor group.3.?-catenin expression: In the process of osteogenic induction of ADSCs,the expression of ?-catenin in the Exiperimental group was significantly up-regulated compared with N-Control group(P <0.05)when treated with 15?g/ml ADSCs-EXO for 7 days.When treated with DKK1 in ADSCs-EXO medium for 7 days,the expression of ?-catenin protein was significantly lower than that of Experimental group,the expression of ?-catenin protein was inhibited and Wnt/?-catenin signaling pathway was blocked.Conclusion:ADSCs-EXO can promote ADSCs osteogenic differentiation by activating Wnt/?-catenin signaling pathway.