The correlation between TGF-b3 and HGF/SF in the process of fusion of secondary palatal shelves

本研究通过体外培养和体内培养的方法，探讨了在胚胎期调控细胞生长的TGF-β和与上皮-间质转化有关的HGF/SF在次级腭突融合过程中的相互作用机制。于胚胎12 ~ 15 d取材，用原位杂交技术检测HGF/SF和TGF-β3 mRNA的表达。此外，我们还研究了HGF/SF或TGF-β3对器官培养的影响，TGF-β3 mRNA从胚胎12天开始在上皮细胞和间充质细胞中表达，胚胎12.5天开始表达明显，胚胎13.5天后消失，HGF/SF mRNA从胚胎12天开始在间充质细胞中表达，胚龄13.5天后消失。HGF/SF反义寡核苷酸处理抑制了小鼠次级腭突的融合，但在器官培养中不抑制它们的发育。c-Met中和抗体处理抑制了器官培养中小鼠次级腭架的发育。TGF-β3反义寡核苷酸处理后，在器官培养中抑制了小鼠次级腭突的发育和融合，提示HGF/SF和TGF-β3可能在同一胚胎期表达，且HGF/SF可能在小鼠次级腭突由垂直向水平方向转变时诱导腭端细胞凋亡，TGF-β3可能与小鼠次级腭突向水平方向的生长有关。

In this study, we investigated the mechanism of the corrrelation between TGF-β which regulates the cell growth in the embryonic stage anf HGF/SF which is related to epithelial-mesenchymal transformation in the process of the fusion of secondary palatal shelves in organ culture in vitro and vivo.Palate development was examined by H.E. staining on embryonic day 12〜15, and expression of HGF/SF and TGF-β3, Mrna was investigated by whole mount in situ hybridisation on embryonic day 12〜15. In addition, we conducted to examine whether treatment of HGF/SF or TGF-β3 in organ culture.Expression of TGF-β3 Mrna was detected in epithelial and mesenchymal layer from embryonic day 12, and they were observed markedly on embryonic day 12.5, and disppeared after embryonic day 13.5, Expression of HGF/SF Mrna was also detected in mesenchymal layer from embryonic day 12, and disppeared after embryonic day 13.5. Treatment of HGF/SF antisense oligonucleotide prove inhibited the fusion of mouse secondary palatal shelves,but did not inhibit the development of them in organ culture. Treatment of c-Met neutralizing antibody inhibited the development of mouse secondary palatal shelves in organ culture. Treatment of TGF-β3 antisense oligonucleotide prove inhibited the development and fusion of mouse secondary palatal shelves in organ culture.These findings suggested that HGF/SF and TGF-β3 may express at the same embryonic stage, and HGF/SF may induce apoptosis in the tip of the palate at the time which mouse secondary palatal shelves make a change of direction from vertical position to horizontal position, and TGF-β3 may be related with the growth of mouse secondary palatal shelves to the horizontal direction.