Taniguchi F, Harada T, Yoshida S, Iwabe T, Onohara Y, Tanikawa M, Terakawa N
Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago, Japan.
Mol Reprod Dev. 1998 May;50(1):54-62. doi: 10.1002/(SICI)1098-2795(199805)50:1<54::AID-MRD7>3.0.CO;2-W.
Implantation is a complex process that requires the interaction of the blastocyst, and subsequently, that of the developing embryos with the endometrium. Several growth factors and cytokines are involved in implantation, but the details of their actions as related to the regulation of blastocyst implantation remain unclear. In the present study, the RT-PCR method was used to determine the gene expression of basic fibroblast growth factor (bFGF), keratinocyte growth factor (KGF), FGF receptor 1 (FGFR1), FGF receptor 2 (FGFR2), and KGF receptor (KGFR) in mouse embryos and in the stromal and epithelial cells of the uterine endometrium. Basic FGF and KGF mRNA were expressed in the endometrial cells, but were not expressed in the embryos. The mRNAs of receptors for bFGF and KGF were expressed in the blastocysts and in the in vitro implanting embryos, suggesting that bFGF and KGF may exert paracrine effects on blastocyst implantation. In this mouse model of blastocyst implantation, it was found that transforming growth factor alpha (TGF-alpha) at the concentrations of 1 ng/ml and 10 ng/ml significantly enhanced the blastocyst attachment and trophoblast spreading and increased trophoblast surface area. Relatively high concentrations of bFGF (100-500 ng/ml) significantly enhanced the rates of blastocyst attachment and of trophoblast spreading and promoted the expansion of the surface area of the implanting embryos. Unlike the rates of blastocyst attachment and trophoblast spreading, the surface area of the spreading embryos was significantly increased by addition of KGF (1-100 ng/ml). These results suggest that the bFGF and KGF derived from the endometrial cells exert paracrine effects on the process of implantation by stimulating trophoblast outgrowth through their cognate receptors.
着床是一个复杂的过程，需要囊胚以及随后发育中的胚胎与子宫内膜相互作用。几种生长因子和细胞因子参与着床过程，但它们与囊胚着床调节相关的具体作用细节仍不清楚。在本研究中，采用逆转录聚合酶链反应（RT-PCR）方法来测定小鼠胚胎以及子宫内膜基质细胞和上皮细胞中碱性成纤维细胞生长因子（bFGF）、角质形成细胞生长因子（KGF）、FGF受体1（FGFR1）、FGF受体2（FGFR2）和KGF受体（KGFR）的基因表达。碱性FGF和KGF的信使核糖核酸（mRNA）在子宫内膜细胞中表达，但在胚胎中不表达。bFGF和KGF受体的mRNA在囊胚和体外着床胚胎中表达，这表明bFGF和KGF可能对囊胚着床发挥旁分泌作用。在这个囊胚着床的小鼠模型中，发现浓度为1纳克/毫升和10纳克/毫升的转化生长因子α（TGF-α）显著增强囊胚附着和滋养层扩展，并增加滋养层表面积。相对高浓度的bFGF（100 - 500纳克/毫升）显著提高囊胚附着率和滋养层扩展率，并促进着床胚胎表面积的扩大。与囊胚附着率和滋养层扩展率不同，添加KGF（1 - 100纳克/毫升）可使扩展胚胎的表面积显著增加。这些结果表明，来自子宫内膜细胞的bFGF和KGF通过其同源受体刺激滋养层生长，对着床过程发挥旁分泌作用。
