氨基酸转运载体 LAT1对小鼠胎盘早期建立的影响

摘要

目的：观察L型氨基酸转运载体1（ L－type amino acid transporter 1， LAT1）在妊娠小鼠第8天（ D8）子宫中的表达，探讨LAT1在早期胎盘形成过程中的作用。方法120只6～8周龄SPF级KM雌鼠作为研究对象，免疫组织化学检测LAT1在妊娠小鼠D8子宫中的表达情况，原代分离D8．5的绒毛膜锥（ EPCs ），检测LAT1特异抑制剂2－氨基双环[2．2．1]庚烷－2－羧酸（2－aminobicyclo－（2，2，1）－heptane－2－carboxylic acid， BCH）以及LAT1的作用底物亮氨酸（ L－leucine ）对EPCs黏附及外延生长能力的影响。结果 LAT1高表达于D8子宫蜕膜区，在EPCs中亦呈现阳性表达。 LAT1的特异性抑制剂BCH显著性抑制EPCs 的外延生长，而亮氨酸对EPCs的外延生长抑制作用差异无显著性。结论 LAT1表达于小鼠早期胎盘形成期的子宫中，从而推测LAT1可能促进滋养层对母体蜕膜组织的侵袭，进而参与胎盘早期的建立。%Objective To explore the expression and role of LAT 1 in mouse uterus on early placenta formation on day 8 of pregnancy (D8).Methods One hundred and twenty 6-8-week old SPF female Kunming mice were used in this study.Immunohistochemistry was applied to determine the localization of LAT 1 protein in the mouse uterus on D8 of preg-nancy.The ectoplacental cones (EPCs) were dissected out from D8.5 uterus, and then cultured in vitro with different con-centrations of BCH (2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid, specific antagonist of LAT1) and L-leucine ( substrate of LAT1) to determine the role of LAT1 during the EPC attachment and outgrowth .Results LAT1 protein was highly expressed in secondary decidual zone and also positively expressed in the mouse uterus on D 8.As a specific antago-nist of LAT1, BCH significantly suppressed the ectoplacental cone outgrowth , whereas L-leucine showed no significant effect on it.Conclusions LAT1 is expressed in the mouse uterus during early placenta formation and promotes ectoplacen -tal cone outgrowth , suggesting that LAT1 may promote the trophoblast invasion into maternal decidual tissue , and partici-pates in the early formation of placenta .