Sülz L, Valenzuela J P, Salvatierra A M, Ortiz M E, Croxatto H B
Unidad de Reproducción y Desarrollo, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago.
Hum Reprod. 1998 Oct;13(1O):2916-20. doi: 10.1093/humrep/13.10.2916.
The co-expression of alpha1beta1, alpha4beta1 and alphavbeta3 integrins in the human endometrium coincides with the implantation window. The alphavbeta3 integrin is expressed in the apical surface of the luminal epithelium and may serve to anchor trophoblast cells in the adhesion phase of implantation. Using immunohistochemistry, we compared the expression of alphav, alpha1, alpha4 and beta3 integrin subunits in samples of normal human Fallopian tube and endometrium obtained from five women in the non-receptive period (luteal phase days 2-4) and from another five women in the receptive period (luteal phase days 6-8). The staining was quantified visually on a scale of 0 to ++, according to the intensity and density of stained cells. The alphav subunit is expressed in the Fallopian tube epithelium during both periods in a pericellular distribution. The beta3 subunit is also expressed in the same location, but it is up-regulated during the period of endometrial receptivity. The other subunits are expressed in localizations which are not relevant to trophoblast adhesion and exhibit little or no difference in the level of expression between the non-receptive and receptive periods. Based on these results we postulate that the expression of the beta3 subunit in the human tubal epithelium is under the same systemic controlling signals as in the endometrium and that the normal tubal epithelium may have an implantation window, at about the same time as the endometrium, that affords the opportunity for trophoblast attachment should a 5-7 day embryo be unduly retained in the tube.
α1β1、α4β1和αvβ3整合素在人子宫内膜中的共表达与着床窗期相吻合。αvβ3整合素表达于腔上皮的顶端表面，在着床的黏附期可能有助于锚定滋养层细胞。我们采用免疫组织化学方法，比较了从5名处于非接受期（黄体期第2 - 4天）的女性以及另外5名处于接受期（黄体期第6 - 8天）的女性获取的正常人输卵管和子宫内膜样本中αv、α1、α4和β3整合素亚基的表达情况。根据染色细胞的强度和密度，将染色情况按0至++进行视觉定量。αv亚基在两个时期均以细胞周围分布的形式表达于输卵管上皮。β3亚基也在相同位置表达，但在子宫内膜接受期上调。其他亚基的表达位置与滋养层黏附无关，且在非接受期和接受期之间表达水平几乎没有差异。基于这些结果，我们推测人输卵管上皮中β3亚基的表达与子宫内膜受相同的全身控制信号调控，并且正常输卵管上皮可能与子宫内膜大约在同一时间存在着床窗，若5 - 7天的胚胎在输卵管中过度滞留，该着床窗可为滋养层附着提供机会。
