Bone Marrow Mesenchymal Stem Cells Differentiate Towards A Nucleus Pμlposus-like Phenotype Induced By Combination Of Two Cytokines In Vitro

Objective:To explore the possibility of bone marrow mesenchymal stem cells to differentiate towards a nucleus pμLposus-like phenotype induced by combination of transforming growth factor-beta 1 and growth and differentiation factor-5Methods:Bone marrow mesenchymal stem cells were taken from Sprague Dawley rat. Flow cytometry instrument were employed to detect the expression of CD105, CD90, CD29,CD45, CD44, CD34 and CD24. BMSCs were divided into TGF-β1 group、GDF-5 group、TGF-β1+ GDF-5 group and control group. After 14 days of differentiation, RT-PCR were used to detect the expression of Collagen type Ⅱ, Aggrecan and SOX-9 of each group.Results:The positive expressions of CD105, CD90, CD44, CD29 and negative expressions of CD45, CD34, CD24 of BMSCs were detected by flow cytometry instrument. After 14 days of differentiation, the expression of Collagen type Ⅱ, Aggrecan and SOX-9 in TGF-β1group、GDF-5 group and TGF-β1+ GDF-5 group were significantly higher than that in the control group(P<0.05). The expression of Collagen type Ⅱ, Aggrecan and SOX-9 in TGF-β 1+ GDF-5 group were significantly higher than that in TGF- β 1 group and GDF-5group(P<0.05).Conclusions:These findings suggest that both TGF-β1 and GDF-5 have the ability to induce bone marrow mesenchymal stem cells to differentiate towards a nucleus pμLposus-likephenotype, and there are synergistic effect between them.