Study for regulating mechanism of mesenchymal cells differentiation

通过BrdU掺入实验研究了神经鞘糖脂(GSLS)和神经营养素4(NT-4)在小鼠间充质细胞中的相互作用。结果表明，外源性GM3和LacCer对小鼠间充质细胞的增殖有抑制作用，NT-4对牙间充质细胞的增殖活性有明显的干扰作用。RT-PCR结果显示，NT-4可促进小鼠骨髓间充质细胞中DSPP的表达，当加入GM3或LacCer的培养液中，NT-4的表达水平更高。提示NT-4可能与GSLS在细胞表面协同作用，调节细胞分化。我们用免疫组织化学方法检测了TrkB在小鼠间充质细胞上的表达模式(TrkB可以作为选择性截短的TrkB剪接变体存在)，结果显示全长的TrkB表达，而截短的TrkB不表达。

We investigated the interactions of glycosphingolipids (GSLs) and neurotrophin 4 (NT-4) in the mouse mesenchymal cells.We showed that exogenously added GM3 (monosialoganglioside) and LacCer (lactosylceramide) suppressed the proliferation of mouse mesenchymal cells by BrdU incorporation assay, and that dental mesenchymal cell proliferation activities were significantly disturbed when NT-4 was added to the culture medium with GM3. We revealed that NT-4 increased expression of DSPP in the mouse mesenchymal cells by RT-PCR and those expression levels were enhanced when NT-4 was added to the culture medium with GM3 or LacCer. These results suggested that NT-4 might cooperate with GSLs on cell surface and regulate the differentiation. we examined the expression patterns of TrkB (TrkB can exist as alternatively truncated TrkB splice variants) on mouse mesenchymal cells by immunohistochemistry, and revealed that full-length TrkB were expressed, while truncated TrkB were absent.