Differentiation of bone marrow mesenchymal stem cells（BMMSCs） to nucleus-like pulposus transfected by TGF-β1 in the mimic microgravity environment

English Keywords:Bone marrow mesenchymal stem cells  Differentiation  Nucleus pulposus  TGF-β1  Microgravity

English Abstract:

  【Abstract】 Objective：To observe the differentiation of bone marrow mesenchymal stem cells（BMMSCs） to nucleus-like pulposus phenotype transfected by TGF-β1 and cultured in the mimic microgravity in vitro. Method：Bone marrow mesenchymal stem cells（BMMSCs） obtained from adult rabbit were cultured and proliferated to the third generation，which were assigned into 3 groups as followers：micro-gravity inducing group（group A），BMMSCs transfected by TGF-β1 were cultured in calcium alginate gel beads and rotary cell culture system；inducing group（group B），BMMSCs transfected by TGF-β1 were cultured in calcium alginate gel beads；microgravity differentiation group（group C），BMMSCs were cultured in calcium alginate gel beads and rotary cell culture system.At 3，7，14，21d，the content of TGF-β1 in BMMSCs and the proliferation potency of BMMSCs were detected in all groups respectively，collagen type Ⅱ was detected by immunohistochemical and Toluidine blue staining，the expression of mRNA of proteoglycan and collagen type Ⅱ protein was detected by RT-PCR.Result：At the 14th day，the polygonal nucleus-like pulposus was observed in group A and B，and abnormal cells were observed in group C.From the 3rd day，the content of TGF-β1 in supernate and its DNA in BMMSCs in group A were higher than those in group B and C，and also increased gradually with time.Immunohistochemistry staining of collagen type Ⅱ protein in BMMSCs climbing film showed positive in group A，weak positive in group B，and negative in group C.RT-PCR results showed expression of proteoglycan and collagen type ⅡmRNA in group A and B.Conclusion：BMMSCs transfected by TGF-β1 and cultured in the mimic microgravity can increase the synthesis potential of proeoglycan and collagen type Ⅱ.