Effects of Transforming Growth Factor β1 on the Migration of Bone Marrow Mesenchymal Stem Cells and the Expression of Snail

Abstract: Density gradient centrifugalization combined with adherence method were used to segregate and cultivate rat bone marrow mesenchymal stem cells (BMMSCs). BMMSCs cultivated to the 3rd passage were characterized using immunofluorescence technique. The effects of different concentrations of transforming growth factor β1 (TGF-β1) on the migration and proliferation were detected by the modified Transwell chambers and MTT. Cell apoptosis was detected by flow cytometry (FCM). The effects of TGF-β1 for different time points on the expression of snail and MMP-2 mRNA was measured by RT-PCR， and snail protein expression was detected by immunofluorescence technology and Western blot. Results demonstrated that density gradient centrifugalization combined with adherence method could segregate and purify rat BMMSCs effectively. The results of immunofluorescence stain showed that CD29 and CD44 expression were positive while CD34 and CD45 expression was negative for BMMSCs. The TGF-β1 induced a dose-dependent increase in cell migration， which got the peak at 2 ng/ml， and high concentration of TGF-β1 decreased the cell migration. Cell apoptosis was reduced with 2 ng/ml TGF-β1 and had obvious difference with control groups (P<0.05). The expression level of snail mRNA TGF-β1 treatment at 6 h and the expression level of MMP-2 mRNA at 12 h were significantly higher than the expression level of those at other time points. The protein expression level of snail in TGF-β1-treated group at 24 h was significantly higher than that of control group， but it had no effect on cell proliferation. The study will investigate the possibly molecular mechanisms of TGF-β1on the invasive power of BMMSCs and the expression of snail， and afford experimental foundation for controlling BMMSCs' migrating into brain effectively in vitro.
    

CSTR: 32200.14.cjcb.2008.02.0018