The cytotrophoblast layer of human chorionic villi becomes thinner but maintains its structural integrity during gestation
The cytotrophoblast layer of human chorionic villi becomes thinner but maintains its structural integrity during gestation
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DOI：
10.1095/biolreprod.106.056127
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发表时间：
2007-01-01
影响因子：
3.6
通讯作者：
Takizawa, Toshihiro
中科院分区：
文献类型：
--
作者：
Mori, Miki;Ishikawa, Gen;Takizawa, Toshihiro
人类胎盘中的绒毛膜绒毛是母胎交换的重要结构。根据胚胎学和胎盘学文献，在妊娠早期，细胞滋养层（CTB）层，其位于合体滋养层（STB）下方并由基底层支撑，几乎是完整的，但后来，它变得不连续。在本研究中，我们研究了在正常绒毛树的CTB层的结构完整性，先进的显微镜技术使用的抗体肝细胞生长因子（HGF）激活剂抑制剂1型（SPINT 1），一种有效的抑制剂的HGF激活剂专门表达在绒毛CTB。在足月胎盘中，CTB层的细胞表面散布在基膜上，但不中断。形态学分析表明，在整个绒毛树，80%的连续性的CTB层的足月胎盘和90%的孕早期胎盘被保存。妊娠是伴随着独特的结构变化，在基底域的滋养层。最初的立方形CTB细胞转化为扁平细胞，许多细胞的过程，连同那些相邻的STB，最终覆盖在一个复杂的网络的相互交错的滋养层基膜。此外，SPINT 1、ST 14、HGF和MET mRNA在绒毛树中的表达水平在妊娠过程中增加。这些结果表明，SPINT1阳性CTB层的结构完整性可能在绒毛分化中发挥重要作用，并通过HGF信号系统在妊娠期间维持绒毛树。
Chorionic villi in the human placenta serve as essential structures in fetomaternal exchanges. According to the embryology and placentology literature, during the first trimester, the cytotrophoblast (CTB) layer that is subjacent to the syncytiotrophoblast (STB) and supported by a basal lamina is nearly complete, but later, it becomes discontinuous. In the present study, we investigated the structural integrity of the CTB layer in the normal villous tree by advanced microscopy techniques using an antibody to hepatocyte growth factor (HGF) activator inhibitor type 1 (SPINT1), a potent inhibitor of HGF activators expressed exclusively on villous CTB. In full-term placenta, the cell surface of the CTB layer was spread over the basal lamina but was not interrupted. Morphometric analysis showed that throughout the villous tree, 80% of the continuity of the CTB layer of full-term placenta and 90% of that of first-trimester placenta were preserved. Gestation was accompanied by unique structural change in the basal domain of the trophoblast layer. The initially cuboidal-shaped CTB cells were transformed to flat cells with many cellular processes that, together with those of the adjacent STB, eventually covered the trophoblast basal lamina in a complex network of interdigitations. in addition, the expression levels of SPINT1, ST14, HGF, and MET mRNAs in the villous tree increased over the course of gestation. These results suggest that the structural integrity of the SPINT1-positive CTB layer may play an important role in villous differentiation and in maintenance of the villous tree via the HGF signaling system during gestation.