Jeschke U, Mayr D, Schiessl B, Mylonas I, Schulze S, Kuhn C, Friese K, Walzel H
Ludwig Maximilians University of Munich, Department of Obstetrics and Gynaecology, Maistrasse 11, 80337 Munich, Germany.
Placenta. 2007 Nov-Dec;28(11-12):1165-73. doi: 10.1016/j.placenta.2007.06.006. Epub 2007 Jul 30.
Galectin-1 (gal-1) and galectin-3 (gal-3), which are members of the mammalian beta-galactoside-binding proteins, recognise preferentially (Galbeta1-4GlcNAc) sequences of several cell surface oligosaccharides. In addition, gal-1 also binds to the Thomsen-Friedenreich (TF) antigen (Galbeta1-3GalNAc-).
Slides of frozen and paraffin-embedded placental tissue of patients with fetal intrauterine growth retardation (IUGR), preeclampsia, haemolysis, elevated liver enzymes, low platelets (HELLP) and normal term placentas were incubated with monoclonal and polyclonal antibodies against gal-1, gal-3 and TF. Staining reaction was performed with the avidin-biotinylated peroxidase complex (ABC) reagent. The intensity of the immunohistochemical reaction on the slides was analysed using a semi-quantitative score. The identity of galectin-expressing cells was analysed by using a double immunofluorescence method.
We demonstrated immunohistochemically that the expression of gal-1 and gal-3 on the extravillous trophoblast (EVT) is significantly up-regulated in preeclamptic and HELLP placentas and unchanged compared with normal controls in IUGR placentas. The expression of the TF antigen is significantly up-regulated in IUGR and preeclamptic extravillous trophoblast cells and unchanged in HELLP placentas compared with normal controls. In addition, the expression of gal-1 is significantly up-regulated in the decidual tissue of preeclamptic placentas and in the villous trophoblast tissue of HELLP placentas.
Our data showed that gal-1, gal-3 and TF were up-regulated on the membrane of EVT in preeclamptic placentas. In addition, the expression of gal-1 is significantly up-regulated in decidual tissue of preeclamptic placentas and villous trophoblast tissue of HELLP placentas. Taking into consideration the results of this study, we speculate that expression of both galectins and TF on the membrane of preeclamptic EVT and up-regulation of gal-1 in preeclamptic decidual cells may at least in part compensate for the apoptotic effects of maternal immune cells.
半乳糖凝集素-1（gal-1）和半乳糖凝集素-3（gal-3）是哺乳动物β-半乳糖苷结合蛋白家族成员，它们优先识别几种细胞表面寡糖的（Galβ1-4GlcNAc）序列。此外，gal-1还与汤姆森-弗里德赖希（TF）抗原（Galβ1-3GalNAc-）结合。
将患有胎儿宫内生长受限（IUGR）、先兆子痫、溶血、肝酶升高、血小板减少（HELLP）的患者以及足月胎盘的冷冻和石蜡包埋胎盘组织切片，与抗gal-1、gal-3和TF的单克隆抗体及多克隆抗体一起孵育。用抗生物素蛋白-生物素化过氧化物酶复合物（ABC）试剂进行染色反应。使用半定量评分分析切片上免疫组化反应的强度。采用双重免疫荧光法分析表达半乳糖凝集素的细胞的特性。
我们通过免疫组化证明，在先兆子痫和HELLP胎盘的绒毛外滋养层（EVT）上，gal-1和gal-3的表达显著上调，而与IUGR胎盘的正常对照相比无变化。与正常对照相比，TF抗原在IUGR和先兆子痫的绒毛外滋养层细胞中的表达显著上调，而在HELLP胎盘中无变化。此外，gal-1在先兆子痫胎盘的蜕膜组织和HELLP胎盘的绒毛滋养层组织中的表达显著上调。
我们的数据表明，在先兆子痫胎盘中，gal-1、gal-3和TF在EVT膜上上调。此外，gal-1在先兆子痫胎盘的蜕膜组织和HELLP胎盘的绒毛滋养层组织中的表达显著上调。考虑到本研究的结果，我们推测先兆子痫EVT膜上半乳糖凝集素和TF的表达以及先兆子痫蜕膜细胞中gal-1的上调可能至少部分补偿母体免疫细胞的凋亡作用。
