Austin Kathy J, Bany Brent M, Belden E Lee, Rempel Lea A, Cross James C, Hansen Thomas R
Reproductive Biology Program, Department of Animal Science, University of Wyoming, Laramie, WY 82071-3684, USA.
Endocrinology. 2003 Jul;144(7):3107-13. doi: 10.1210/en.2002-0031.
An early response of the human and bovine endometrium to pregnancy is induction of an interferon (IFN)-stimulated gene (ISG) that encodes the ubiquitin-related protein, ISG15. Because the mode of implantation differs among species, we tested whether Isg15 mRNA was also expressed in the mouse uterus in response to the implanting conceptus. Isg15 mRNA was detected in the mouse uterus and increased after d 4.5 of pregnancy but did not change between d 3.5 and 9.5 of pseudopregnancy. Within the decidua, Isg15 mRNA was localized to the antimesometrial zone of the implantation sites. The level of Isg15 mRNA in artificially induced deciduomas was similar to the nonpregnant uterus and was approximately 10-fold lower than in the pregnant uterus. In vitro, murine decidual cells derived from artificially induced deciduomas could be induced to produce the Isg15 protein as well as Isg15-conjugated proteins when stimulated with type 1 IFN, though were less responsive to IFN-gamma. Isg15 is one of few gene products identified in murine implantation sites to require presence of the conceptus and not simply differentiation of the stroma. In vitro data support the inference that the pregnancy-specific inducer of uterine Isg15 is a type 1 IFN or a cytokine that signals through a similar pathway.
人和牛子宫内膜对妊娠的早期反应是诱导一种干扰素（IFN）刺激基因（ISG），该基因编码泛素相关蛋白ISG15。由于不同物种的着床方式不同，我们测试了Isg15 mRNA是否也在小鼠子宫中因着床期胚胎而表达。在小鼠子宫中检测到Isg15 mRNA，且在妊娠第4.5天之后增加，但在假孕第3.5天至9.5天之间没有变化。在蜕膜内，Isg15 mRNA定位于着床部位的反系膜区。人工诱导蜕膜瘤中Isg15 mRNA的水平与未孕子宫相似，比孕子宫低约10倍。在体外，来自人工诱导蜕膜瘤的小鼠蜕膜细胞在用1型干扰素刺激时可被诱导产生Isg15蛋白以及Isg15缀合蛋白，不过对干扰素-γ的反应较弱。Isg15是在小鼠着床部位鉴定出的少数几种需要胚胎存在而非仅仅基质分化的基因产物之一。体外数据支持这样的推断，即子宫Isg15的妊娠特异性诱导物是1型干扰素或通过类似途径发出信号的细胞因子。
