Nagaoka Kentaro, Nojima Hisashi, Watanabe Fumiko, Chang Kyu-Tae, Christenson Ronald K, Sakai Senkiti, Imakawa Kazuhiko
Laboratory of Animal Breeding, Faculty of Agriculture, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
J Biol Chem. 2003 Aug 1;278(31):29048-56. doi: 10.1074/jbc.M300470200. Epub 2003 May 19.
For a pregnancy to be established, initial apposition and adhesion of the blastocyst to maternal endometrium must occur in a coordinated manner; however, a key factor(s) that mediates the trophoblast cell migration and attachment to the apical surface of the endometrium has not been identified. In this study, we examined the effect of an endometrial chemokine, interferon-gamma-inducible protein 10 kDa (IP-10), on conceptus migration to the endometrial epithelium. We first studied endometrial IP-10 mRNA expression, which was localized in the subepithelial stromal region, and detected the protein in the uterine flushing media during early pregnancy. Expression of IP-10 mRNA by the endometrium of cyclic animals was stimulated by the addition of a conceptus factor interferon-tau (IFN-tau). Immunofluorescent analysis revealed that IP-10 receptor, CXCR3, was localized in the trophoblast cells, to which biotinylated-recombinant caprine IP-10 (rcIP-10) bound. Chemotaxis assay indicated that rcIP-10 stimulated the migration of trophoblast cells, and the effects of rcIP-10 were neutralized by the pretreatment with an anti-IP-10 antibody. Adhesive activity of trophoblast cells to fibronectin was promoted by rcIP-10, and the effect was inhibited by the use of anti-IP-10 antibody. Further adhesion experiments demonstrated that binding of trophoblast cells to fibronectin was completely inhibited by a peptide of the Arg-Gly-Asp (RGD) sequence, which binds to integrins alpha5beta1, alphaVbeta1, alphaVbeta3, and alphaVbeta5, whereas non-binding peptide containing Arg-Gly-Glu (RGE) had minimal effects. More importantly, rcIP-10 promoted the adhesion of trophoblast cells to primary cells isolated from endometrial epithelium. Furthermore, rcIP-10 stimulated the expression of integrin alpha5, alphaV, and beta3 subunit mRNA in trophoblast cells. These findings suggest that endometrial IP-10 regulates the establishment of apical interactions between trophoblast and epithelial cells during early gestation.
为了成功着床，囊胚与母体子宫内膜的初始附着和黏附必须以协调的方式发生；然而，介导滋养层细胞迁移并附着于子宫内膜顶端表面的关键因素尚未明确。在本研究中，我们检测了一种子宫内膜趋化因子——γ干扰素诱导蛋白10 kDa（IP-10）对孕体向子宫内膜上皮迁移的影响。我们首先研究了子宫内膜IP-10 mRNA的表达情况，其定位于上皮下基质区域，并在妊娠早期的子宫冲洗液中检测到了该蛋白。添加孕体因子干扰素-τ（IFN-τ）可刺激周期性动物子宫内膜中IP-10 mRNA的表达。免疫荧光分析显示，IP-10受体CXCR3定位于滋养层细胞，生物素化重组山羊IP-10（rcIP-10）可与之结合。趋化性分析表明，rcIP-10可刺激滋养层细胞的迁移，且抗IP-10抗体预处理可中和rcIP-10的作用。rcIP-10可促进滋养层细胞与纤连蛋白的黏附活性，而抗IP-10抗体可抑制该作用。进一步的黏附实验表明，与整合素α5β1、αVβ1、αVβ3和αVβ5结合的精氨酸-甘氨酸-天冬氨酸（RGD）序列肽可完全抑制滋养层细胞与纤连蛋白的结合，而含精氨酸-甘氨酸-谷氨酸（RGE）的非结合肽作用极小。更重要的是，rcIP-10可促进滋养层细胞与从子宫内膜上皮分离的原代细胞的黏附。此外，rcIP-10可刺激滋养层细胞中整合素α5、αV和β3亚基mRNA的表达。这些发现表明，子宫内膜IP-10在妊娠早期调节滋养层与上皮细胞顶端相互作用的建立。
