Lysiak J J, Han V K, Lala P K
Department of Anatomy, University of Western Ontario, London, Canada.
Biol Reprod. 1993 Nov;49(5):885-94. doi: 10.1095/biolreprod49.5.885.
Transforming growth factor alpha (TGF alpha) is an important growth regulatory molecule, the location and function of which at the human fetomaternal interface remain to be determined. The present study examined the presence of TGF alpha in the human placenta, decidua, and fetal membranes throughout gestation (from a total of 29 subjects) as well as its functional role in the proliferation of first trimester trophoblasts. The peptide was localized immunocytochemically with a monoclonal anti-TGF alpha antibody (Ab) (MF9) on paraffin-embedded tissues via the avidin-biotin complex-peroxidase technique with diaminobenzidine (DAB) as the chromogen. Omission or TGF alpha absorption of the primary Ab served as negative controls. Specific (cytoplasmic) staining was noted in typical stromal-type decidual cells, including cells of the decidua basalis and parietalis and chorionic decidua, throughout gestation. Villous trophoblast cells (syncytiotrophoblast and to a minor extent cytotrophoblast) at all gestational ages as well as extravillous cytotrophoblast cells (intermediate and cytotrophoblastic shell) also showed specific cytoplasmic staining. Chorionic trophoblasts showed variable staining, and little or no immunoreactivity was seen in the amniocytes. Second-passage first trimester human trophoblast cells (characterized by their expression of cytokeratin as well as other markers) were cultured in the presence of TGF alpha or neutralizing anti-TGF alpha Ab (TAb-1) or no additive for 18 h prior to exposure to 3H-TdR for 6 h to measure 3H-TdR uptake. TGF alpha (0-100 ng/ml) caused a dose-dependent stimulation of proliferation, reaching a near plateau at 6-100 ng/ml to slightly more than double the basal level. The presence of anti-TGF alpha Ab alone (25 micrograms/ml) did not significantly influence the proliferation of the cells, indicating the absence of significant endogenous TGF alpha in these cultures; however, the Ab was able to abolish the stimulatory function of exogenous TGF alpha. Exogenous TGF alpha also increased the number of trophoblast nuclei immunoreactive for proliferating cell nuclear antigen and reduced the incidence of multinucleate cells in culture. These results indicate that TGF alpha is present in the cells of the fetomaternal interface throughout human gestation and may function as a stimulator of trophoblastic growth in situ.
转化生长因子α（TGFα）是一种重要的生长调节分子，其在人胎儿 - 母体界面的位置和功能尚待确定。本研究检测了整个孕期（共29名受试者）人胎盘、蜕膜和胎膜中TGFα的存在情况，以及它在孕早期滋养层细胞增殖中的功能作用。通过抗生物素蛋白 - 生物素复合物 - 过氧化物酶技术，以二氨基联苯胺（DAB）作为显色剂，用单克隆抗TGFα抗体（Ab）（MF9）对石蜡包埋组织进行免疫细胞化学定位。省略一抗或用TGFα吸收一抗作为阴性对照。在整个孕期，典型的基质型蜕膜细胞，包括基蜕膜、壁蜕膜和绒毛膜蜕膜的细胞中均可见特异性（细胞质）染色。所有孕周的绒毛滋养层细胞（合体滋养层细胞以及少量的细胞滋养层细胞）以及绒毛外细胞滋养层细胞（中间型和细胞滋养层壳）也显示出特异性细胞质染色。绒毛膜滋养层细胞染色情况不一，羊膜细胞中几乎没有或没有免疫反应性。将第二代孕早期人滋养层细胞（以其细胞角蛋白及其他标志物的表达为特征）在TGFα或中和性抗TGFα抗体（TAb - 1）存在的情况下培养，或不添加任何物质培养18小时，然后暴露于3H - TdR中6小时以测量3H - TdR摄取量。TGFα（0 - 100 ng/ml）引起剂量依赖性的增殖刺激，在6 - 100 ng/ml时达到接近平台期，比基础水平增加略超过两倍。单独存在抗TGFα抗体（25μg/ml）对细胞增殖没有显著影响，表明这些培养物中没有显著的内源性TGFα；然而，该抗体能够消除外源性TGFα的刺激功能。外源性TGFα还增加了对增殖细胞核抗原呈免疫反应性的滋养层细胞核数量，并降低了培养物中多核细胞的发生率。这些结果表明，TGFα在人类孕期全过程中存在于胎儿 - 母体界面的细胞中，可能在原位作为滋养层生长的刺激因子发挥作用。
