Sawa H, Ukita H, Fukuda M, Kamada H, Saito I, Obrink B
Department of Neurosurgery, Kyorin University, School of Medicine, Tokyo, Japan.
J Histochem Cytochem. 1997 Jul;45(7):1021-34. doi: 10.1177/002215549704500711.
We investigated the expression of the immunoglobulin superfamily cell adhesion molecule, C-CAM, in developing and mature rat placenta. By immunohistochemical staining at the light microscopic level, no C-CAM-expression was seen before Day 9 of gestation, when it appeared in the trophoblasts of ectoplacental cones. On Day 10.5, spongiotrophoblasts and invasive trophoblasts around the maternal vessels of the decidua basalis were stained positively. On Day 12.5, C-CAM was detected in the spongiotrophoblasts of the junctional layer, but labyrinth trophoblasts and secondary giant trophoblasts were not stained. On Day 17.5, C-CAM was found only in the labyrinth and lacunae of the junctional layer. At this stage, both the labyrinth cytotrophoblasts of the maternal blood vessels and the endothelial cells of the embryonic capillaries were strongly stained. Placental tissues from gestational Days 12.5 and 17.5 were analyzed by immunoelectron microscopy to determine the location of C-CAM at the subcellular level. On Day 12.5, positive staining of the spongiotrophoblasts was observed, mainly on surface membranes and microvilli between loosely associated cells. On Day 17.5, staining was found primarily on the microvilli of the maternal luminal surfaces of the labyrinth cytotrophoblasts, and both on the luminal surface and in the cytoplasm of endothelial cells of the embryonic vessels. RT-PCR analysis and Southern blotting of the PCR products revealed expression of mRNA species for both of the major isoforms, C-CAM1 and C-CAM2. Immunoblotting analysis of C-CAM isolated from 12.5-day and 14.5-day placentae showed that it appeared as a broad band with an apparent molecular mass of 110-170 kD. In summary, C-CAM was strongly expressed in a specific spatiotemporal pattern in trophoblasts actively involved in formation of the placental tissue, suggesting an important role in placental development. In the mature placenta, C-CAM expression was confined to the trophoblastic and endothelial cells lining the maternal and embryonic vessels, respectively, suggesting important functions in placental physiology.
我们研究了免疫球蛋白超家族细胞黏附分子C-CAM在发育中和成熟大鼠胎盘中的表达情况。通过光镜水平的免疫组织化学染色，在妊娠第9天之前未观察到C-CAM表达，第9天时其出现在外胎盘锥的滋养层细胞中。在第10.5天，基底蜕膜母体血管周围的海绵滋养层细胞和侵入性滋养层细胞呈阳性染色。在第12.5天，在连接层的海绵滋养层细胞中检测到C-CAM，但迷路滋养层细胞和次级巨滋养层细胞未被染色。在第17.5天，C-CAM仅在连接层的迷路和腔隙中被发现。在此阶段，母体血管的迷路细胞滋养层细胞和胚胎毛细血管的内皮细胞均被强烈染色。对妊娠第12.5天和第17.5天的胎盘组织进行免疫电子显微镜分析，以确定C-CAM在亚细胞水平的定位。在第12.5天，观察到海绵滋养层细胞呈阳性染色，主要位于松散连接细胞之间的表面膜和微绒毛上。在第17.5天，染色主要见于迷路细胞滋养层细胞母体腔表面的微绒毛上，以及胚胎血管内皮细胞的腔表面和细胞质中。RT-PCR分析及PCR产物的Southern印迹显示，两种主要异构体C-CAM1和C-CAM2的mRNA均有表达。对从第12.5天和第14.5天胎盘分离的C-CAM进行免疫印迹分析表明，它呈现为一条宽带，表观分子量为110 - 170 kD。总之，C-CAM在积极参与胎盘组织形成的滋养层细胞中以特定的时空模式强烈表达，提示其在胎盘发育中起重要作用。在成熟胎盘中，C-CAM表达分别局限于衬于母体和胚胎血管的滋养层细胞和内皮细胞，提示其在胎盘生理中具有重要功能。
