Molecular Mechanism of Epithelial-Mesenchymal Interaction

1.腺胃上皮细胞在无间充质培养时表达组织蛋白酶E，但不表达胃蛋白酶原，而在有间充质培养时表达胃蛋白酶原。因此，我们得出结论：腺胃上皮细胞的分化是由上皮-间充质相互作用决定的。2.肝细胞生长因子(HGF)区域特异性刺激原代培养的胃肠上皮细胞增殖。RT-PCR分析显示，胃肠间充质和上皮细胞分别表达HGF和HGF受体。因此，HGF参与了胃肠上皮-间充质间的相互作用。3.角质细胞生长因子(KGF)对原代培养的胃肠上皮细胞也具有区域特异性的促增殖作用。RT-PCR分析显示，胃肠间充质和上皮细胞分别表达KGF和KGF受体。因此，我们认为KGF也参与了胃肠器官上皮-间充质的相互作用。4.用定量RT-PCR方法研究了HGF和KGF在腺胃发育中的作用。HGF和HGF受体的基因在形态发生期表达，KGF和KGF受体的基因在形态发生期后表达。因此，我们得出结论，这两种生长因子在腺胃的发育中起着不同的作用。

1.Glandular stomach epithelial cells expressed Cathepsin E but not pepsinogen when cultured in the absence of mesenchyme, but they expressed pepsinogen when cultured with mesenchyme. We thus concluded that the differentiation of glandular stomach epithelial cells is determined by the epithelial-mesenchymal interaction.2.Hepatocyte growth factor (HGF) region-specifically stimulated proliferation of gastro-intestinal epithelial cells in primary culture. RT-PCR analysis showed that gastro-intestinal mesenchymes and epithelia express HGF and HGF receptors, respectively. We thus concluded that HGF is involved in the epithelial-mesenchymal interaction in gastro-intestinal organs.3.Keratinocyte growth factor (KGF) also region-specifically stimulated proliferation of gastro-intestinal epithelial cells in primary culture. RT-PCR analysis showed that gastro-intestinal mesenchymes and epithelia express KGF and KGF receptors, respectively. We thus concluded that KGF is also involved in the epithelial-mesenchymal interaction in gastro-intestinal organs.4.The role of HGF and KGF in the development of glandular stomach was investigated by quantitative RT-PCR.Genes for HGF and HGF receptor were expressed at the morphogenetic period, and those for KGF and KGF receptor after the morphogenetic period. Thus we concluded that these two growth factors play different roles in developing glandular stomachs.