Pinopode and Mucin 1 (MUC1) have both been proposed as morphological and molecular markers of endometrial receptivity for implantation. However, their spatial relationship in luminal epithelium and its association with reproductive failure are still unclear. This was a prospective cohort study conducted at a university assisted reproductive unit including 9 receptive control women, 18 infertile women, and 22 women with recurrent implantation failure (RIF) and 22 women with recurrent miscarriage (RM). Endometrial tissues were obtained at 7 days after luteinizing hormone surge during implantation window. Luminal epithelium was examined by scanning electron microscopy (SEM). MUC1 localization in luminal epithelium was detected by scanning immunoelectron microscopy (SIM) and compared by modified double immunofluorescence (mIF) staining without antigen retrieval. SEM did not show any significant difference in percentage of secretory cells, any stage of pinopodes, and ciliated cells between control, infertility, RIF and RM groups. SIM identified MUC1 was mainly localized on surface of ciliated cells and at the bottom of cilia, not secretory cells and pinopodes, and its specific localization was validated by mIF staining. MUC1 expression in ciliated cells in control women was significantly higher than those women with reproductive failure, but there was no significant difference between RIF and RM. In conclusion, MUC1 is mainly expressed in ciliated cells, not secretory cells and pinopodes, of the endometrial luminal epithelium during implantation window. The specific expression of MUC1 in the ciliated cells in receptive control women is higher than that of women with reproductive failure during implantation window.

中文翻译：

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Mucin 1在子宫内膜腔上皮中的定位及其在植入窗期间有生殖衰竭的女性中的表达。

Pinopode和Mucin 1（MUC1）均已被提出作为子宫内膜植入的形态学和分子标记。然而，它们在腔上皮细胞中的空间关系及其与生殖衰竭的关系仍不清楚。这是一项在大学协助的生殖单位中进行的前瞻性队列研究，其中包括9名接受接受控制的女性，18名不育女性和22例复发性植入失败（RIF）和22例复发性流产（RM）的女性。在植入窗口黄素化激素激增后第7天获得子宫内膜组织。通过扫描电子显微镜（SEM）检查发光上皮。通过扫描免疫电子显微镜（SIM）检测MUC1在腔上皮中的定位，并通过改良的双免疫荧光（mIF）染色进行比较，而无需进行抗原回收。扫描电镜未显示对照组，不育组，RIF组和RM组之间的分泌细胞百分比，pinopode的任何阶段和纤毛细胞的任何显着差异。SIM鉴定出MUC1主要定位在纤毛细胞表面和纤毛底部，而不是分泌细胞和pinopodes，其特异性定位已通过mIF染色验证。对照女性的纤毛细胞中MUC1的表达明显高于那些生殖衰竭的女性，但RIF和RM之间没有显着差异。总之，MUC1主要在纤毛细胞中表达，而不在分泌细胞和pinopode中表达，植入窗口期间子宫内膜腔上皮的变化 接受控制的女性的纤毛细胞中MUC1的特异性表达高于在植入窗口期间具有生殖衰竭的女性。