Klein C, Scoggin K E, Troedsson M H T
Department of Veterinary Science, 108 Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA.
Reprod Domest Anim. 2011 Aug;46(4):692-8. doi: 10.1111/j.1439-0531.2010.01731.x. Epub 2011 Jan 17.
Establishment of pregnancy is critically dependent upon a precisely orchestrated embryo-maternal interaction leading to a receptive uterine environment. The up-regulation of the interferon-stimulated protein 15 kDa (ISG15) during pregnancy has been described in various species and has been hypothesized to be part of the molecular repertoire that makes the uterus receptive to conceptus development. In the current study, the expression of ISG15 and enzymes involved in ISG15ylation was examined at the mRNA and protein level in equine endometrium at Day 14 of the luteal phase and at Day 14 and 50 of pregnancy. ISG15 mRNA showed a 2.63-fold higher expression at Day 14 of pregnancy when compared to Day 14 of the cycle, while mRNA abundance at Day 50 of pregnancy was unchanged compared to Day 14 of the cycle. Upon Western blot analysis using anti-ISG15 antibody, several higher molecular weight bands could be observed, representing proteins conjugated to ISG15. No free ISG15 could be detected. The pattern of ISG15 reactive proteins differed from those observed in non-uterine samples. Upon immunohistochemistry, ISG15 reactive proteins located primarily to luminal and glandular epithelial cells, while stromal cells showed weaker staining. In conclusion, the expression of ISG15-conjugated proteins in equine endometrium did not differ between cyclic and pregnant 14 days after ovulation and Day 50 of pregnancy. It is hypothesized that the unique subset of ISG15ylated proteins expressed in endometrial tissue contributes to normal cellular function and that, unlike other species, the modification of ISG15-conjugated proteins is not an active contributor to conceptus-maternal interaction in the mare.
妊娠的建立严重依赖于精确协调的胚胎 - 母体相互作用，从而形成一个适宜着床的子宫环境。在多种物种中都已描述了孕期干扰素刺激蛋白15 kDa（ISG15）的上调，并且据推测它是使子宫接受胚胎发育的分子机制的一部分。在本研究中，检测了黄体期第14天、妊娠第14天和第50天马子宫内膜中ISG15及参与ISG15化的酶在mRNA和蛋白质水平的表达。与发情周期第14天相比，妊娠第14天ISG15 mRNA表达高出2.63倍，而妊娠第50天的mRNA丰度与发情周期第14天相比没有变化。使用抗ISG15抗体进行蛋白质印迹分析时，可以观察到几条分子量更高的条带，代表与ISG15结合的蛋白质。未检测到游离的ISG15。ISG15反应性蛋白的模式与在非子宫样本中观察到的不同。免疫组织化学显示，ISG15反应性蛋白主要定位于腔上皮和腺上皮细胞，而基质细胞染色较弱。总之，排卵后14天的发情周期和妊娠第50天，马子宫内膜中ISG15结合蛋白的表达没有差异。据推测，子宫内膜组织中表达的ISG15化蛋白的独特子集有助于正常细胞功能，并且与其他物种不同，ISG15结合蛋白的修饰并非母马中胚胎 - 母体相互作用的积极促成因素。
