Maternal and Fetal Health Research, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, M13 9WL, UK.
Reproduction. 2010 May;139(5):905-14. doi: 10.1530/REP-09-0271. Epub 2010 Feb 23.
Our limited understanding of the processes underlying steroid hormonal control of human endometrial receptivity is largely due to the lack of a relevant model system. To overcome scarcity of material, we have developed a model in which mouse embryos attach to human Ishikawa cells, which express functional steroid hormone receptors. Blastocysts flushed from day 4 pregnant superovulated mice were transferred to confluent Ishikawa cell monolayers. After 48 h of co-culture, 85% of the blastocysts had attached loosely, but only 40% attached stably to the epithelial cell surface. In contrast, 95% of the embryos attached stably to tissue culture plastic. Thus, weak attachment of a majority of the embryos was followed by stronger adhesion of a smaller proportion. Seventeen percent of the transferred blastocysts modified the epithelial cell surface with loss of MUC1 at the attachment site, extending variably to adjacent epithelial cells. Initially, stable attachment occurred without disruption to the integrity of the epithelial monolayer, but at later stages after the embryo had spread laterally, displacement of subjacent cells was observed. A modest increase in stable attachment, but no changes to MUC1 clearance, was observed after assisted hatching. After 24 h priming of Ishikawa cells by 17beta-oestradiol (OE(2)) followed by 72-h incubation with medroxyprogesterone acetate and OE(2), stable attachment increased from 40 to 70%. Initial attachment is efficient either in the presence or in the absence of hormone; steroid treatment increased the incidence of stable attachment. Implantation failure is predicted to occur in this model when embryos fail to progress from initial to stable attachment.
我们对甾体激素控制人类子宫内膜容受性的过程的有限认识在很大程度上是由于缺乏相关的模型系统。为了克服材料的缺乏，我们开发了一种模型，其中将附着在表达功能性甾体激素受体的人 Ishikawa 细胞上的小鼠胚胎。从超排卵的第 4 天怀孕的小鼠冲洗出胚泡，并将其转移到汇合的 Ishikawa 细胞单层上。共培养 48 小时后，85%的胚泡松散附着，但只有 40%稳定附着在上皮细胞表面。相比之下，95%的胚胎稳定附着在组织培养塑料上。因此，大多数胚胎的弱附着随后是较小比例的更强附着。转移的胚泡中有 17%在附着部位用 MUC1 修饰上皮细胞表面，延伸到相邻的上皮细胞。最初，稳定附着发生时上皮单层的完整性没有受到破坏，但在胚胎横向扩散后的后期阶段，观察到下方细胞的位移。辅助孵化后，稳定附着略有增加，但 MUC1 清除无变化。用 17β-雌二醇（OE(2)）对 Ishikawa 细胞进行 24 小时预刺激，然后用醋酸甲羟孕酮和 OE(2)孵育 72 小时后，稳定附着从 40%增加到 70%。初始附着在有或没有激素的情况下都是有效的；甾体激素处理增加了稳定附着的发生率。当胚胎不能从初始附着进展到稳定附着时，预测在这个模型中会发生植入失败。
