Abstract:

Abstract:Objective To induce bone mesenchymal stem cells (MSCs) of rabbits to differentiate directionally into chondrocytes in vitro and to observe the morphology of cells and detect the function,and to discuss the necessary differentiation condition in vitro.Methods The MSCs and chondrocytes were isolated from rabbits and cultured in vitro.The supernatant of chondrocytes in the first three passages  were collected and used to induce transformation of MSCs for 14 d.Three experimental groups were set up: negative control group,experimental group and positive control group.After 14 d of induction,the  morphology of the cells in each group was observed，and the specific  proteins were observed by toluidine blue staining,and  the alkaline phosphatase (ALP) activities were detected，and the collegen Ⅱ(Col Ⅱ) mRNA expressions were detected by RT-PCR.Results 14 d after  induction,compared with negative control group,the induced MSCs in experimental group changed into polygonal shape from spindle shape and there was positive  appearance of toluidine blue staining,the ALP activity and Col Ⅱ mRNA expression were  increased significantly compared with the other two groups(P<0.01).In negative control group, there was negative  appearance  of toluidine blue staining and Col Ⅱ mRNA expression.In  positive control group, there was  positive  appearance  of   toluidine blue staining and Col Ⅱ mRNA expression.Conclusion The supernatant of chondrocytes from rabbits can promote the  MSCs differentiate into chondrocytes in vitro.

Key words:  bone mesenchymal stem cells;differentiation;supernatant of chondrocytes;rabbits