细胞表面半乳糖基转移酶介导外胎盘锥扩展和次生滋养层巨细胞迁移的证据

细胞表面半乳糖基转移酶（ＧａｌＴａｓｅ）是层粘连蛋白（ＬＮ）非整合素类受体，能与其上寡糖链的Ｎ－乙酰葡糖胺（ＧｌｃＮＡｃ）残基识别和结合。作者从妊娠第８．５天雌鼠子宫蜕膜中剥离胚胎，显微分离外胎盘锥（ＥＰＣ）后进行体外培养。用（１）ＬＮ预先半乳糖基化；（２）外源ＧｌｃＮＡｃ底物竞争；（３）ＧａｌＴａｓｅ抗体阻断；（４）α乳清蛋白处理等方法干扰滋养层细胞与ＬＮ的相互作用，均对ＥＰＣ粘附无影响，但抑制ＥＰＣ扩展和次生滋养层巨细胞（ＳＴＧＣｓ）迁移。证明ＧａｌＴａｓｅ虽不参与ＥＰＣ起初的粘附，但通过与ＬＮ寡糖链上ＧｌｃＮＡｃ的结合介导ＥＰＣ扩展和ＳＴＧＣｓ迁移。

Evidences of cell surface β1,4 galactosyltransferase mediating ectoplacental cone outgrowth and secondary trophoblast giant cells migration on laminin in vitro

Objective: To study the role of cell surface β1 4 galactosyltransferase (GalTase) during mouse ectoplacental cone (EPC) outgrowth on laminin (LN). Design: Experiments with mouse EPCs culture in vitro. Setting: State Key Laboratory of Reproductive Biology. Methods:Interfered trophoblastic cell surface GalTase binding to its N acetylglucosamine (GlcNAc) residues associated with LN oligosaccharides by LN pre galactosylation,with exogenous GlcNAc,anti bovine milk GalTase (aBMGT) IgG and α lactalbumin. Results: LN pre galactosylation didn't effect EPC attachment,but decreased EPC outgrowth rate and secondary trophoblast giant cells (STGCs) migrated distance.Although exogenous competitive GlcNAc substrates had no effect on EPC adhesion,it prevented EPC outgrowth and STGCs migration in a dose dependent manner.100μg/ml aBMGT IgG was effective in blockage of EPC outgrowth and STGCs migration,while ineffective to block EPC attachment.Change of GalTase specificity by αLA didn't perturb EPC adhesion,while inhibition of EPC outgrowth and STGCs migration were observed at 48h and 72h,and it increased with the time of culture.All these data show that,although murine trophoblast cell surface GalTase does not involve in EPC initial adhesion to LN,it mediates subsequent EPC outgrowth and STGCs migration by binding to GlcNAc substrates of LN. Conclusion: The results indicated that cell surface β1,4 galactosyltransferase mediates ectoplacental cones outgrowth and secondary trophoblast giant cells migration,although doesn't involve in the initial attachment of ectoplacental cones on laminin in vitro.