Michie H J, Head J R
Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas 75235-9051.
Biol Reprod. 1994 Jun;50(6):1277-86. doi: 10.1095/biolreprod50.6.1277.
Tenascin is a large extracellular matrix (ECM) protein generally restricted to developing embryonic tissues and tissues undergoing remodelling in the adult, but it has been suggested that tenascin is immunomodulatory. In this study we have used indirect immunofluorescence to investigate the distribution of tenascin within the uteri of pregnant and non-pregnant rats. The non-pregnant uterus expressed tenascin in the stroma around the glands, but only the subluminal stroma showed cyclical variations. Dependence of the latter on progesterone was verified in ovariectomized animals supplemented with steroid hormones. During early pregnancy, the uterine circular smooth muscle maintained an intense expression of tenascin. In the decidualizing endometrium, tenascin expression showed dramatic changes that reflected the regionalization of the decidualization process. On Day 6 (blastocyst attachment), tenascin immunoreactivity was prominent in the primary decidualization zone immediately surrounding the conceptus. On Day 7, expression had increased within the secondary decidua that had developed throughout the antimesometrial endometrium. By Day 8, the antimesometrial decidua showed diminished tenascin immunoreactivity; expression became largely confined to the ECM of the developing decidua in the mesometrial region, where levels were high. On Day 10, the well-developed mesometrial decidua was negative. Interestingly, tenascin expression was up-regulated in the walls of the vessels in the metrial gland within the mesometrial triangle beginning on Day 10 of pregnancy. From these studies we conclude that tenascin expression may be an important reflection of the dynamics involved with tissue restructuring during early pregnancy and may play a role in immunomodulation, since expression of this protein in the mesometrial decidua coincides with the presence of differentiating natural killer cell lineage lymphocytes in the same region.
腱生蛋白是一种大型细胞外基质（ECM）蛋白，通常局限于发育中的胚胎组织以及成年期经历重塑的组织，但有人提出腱生蛋白具有免疫调节作用。在本研究中，我们使用间接免疫荧光法来研究腱生蛋白在怀孕和未怀孕大鼠子宫内的分布情况。未怀孕的子宫在腺体周围的基质中表达腱生蛋白，但只有腔下基质表现出周期性变化。在补充了类固醇激素的去卵巢动物中证实了后者对孕酮的依赖性。在怀孕早期，子宫环形平滑肌持续强烈表达腱生蛋白。在蜕膜化的子宫内膜中，腱生蛋白的表达呈现出显著变化，反映了蜕膜化过程的区域化。在第6天（胚泡着床），腱生蛋白免疫反应性在紧邻孕体的初级蜕膜化区域中很突出。在第7天，在整个子宫系膜对侧子宫内膜发育形成的次级蜕膜中表达增加。到第8天，子宫系膜对侧蜕膜的腱生蛋白免疫反应性减弱；表达主要局限于子宫系膜区域发育中的蜕膜的细胞外基质，其水平较高。在第10天，发育良好的子宫系膜蜕膜呈阴性。有趣的是，从怀孕第10天开始，子宫系膜三角区内子宫腺中的血管壁上腱生蛋白表达上调。从这些研究中我们得出结论，腱生蛋白的表达可能是怀孕早期组织重构相关动态变化的重要反映，并且可能在免疫调节中发挥作用，因为该蛋白在子宫系膜蜕膜中的表达与同一区域中分化的自然杀伤细胞系淋巴细胞的存在相一致。
