Hampton A L, Butt A R, Riley S C, Salamonsen L A
Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
Biol Reprod. 1995 Aug;53(2):302-11. doi: 10.1095/biolreprod53.2.302.
Tissue inhibitors of metalloproteinases (TIMPs) have an important role in remodeling of tissues and are likely to be implicated in uterine function, including embryo implantation and placentation. Expression of mRNA for TIMP-1 and TIMP-2 was examined by Northern analysis of endometrial RNA derived from steroid-treated ovariectomized ewes and from intact ewes during the estrous cycle and early pregnancy. Expression of mRNA for TIMP-1 (transcript size 0.9 kb), high in ovariectomized ewes, was substantially reduced by estrogen and to a lesser extent by progesterone. In cyclic and pregnant animals, abundance remained low until Day 10 and then increased, with high abundance continuing to Day 20 in the pregnant animals. Two transcripts for TIMP-2 were detected in ovine tissues--the 3.5-kb transcript and, in greater abundance, the 1.0-kb transcript. In ovariectomized ewes, endometrial abundance of both transcripts was low, and it decreased following estrogen treatment but was stimulated by progesterone alone or progesterone in the presence of estrogen. Abundance of TIMP-2 mRNA increased from Day 4 to Day 14 of the cycle. During early pregnancy, expression of the 1.0-kb transcript increased from Day 4 to Days 12-14 and was maintained at a high level to Day 20, whereas the 3.5-kb transcript decreased after Day 14 to very low levels by Day 20. In contrast with this pattern of regulated expression of TIMP, mRNA for proMMP-1 and for proMMP-3 was not detectable in any of the same tissues by Northern analysis. TIMP-1 protein was immunolocalized to both epithelium and stroma of intact endometrium, and the intensity of immunostaining was correlated with mRNA levels. TIMP-1 was secreted by both epithelial and stromal cells in primary culture, and its identity was confirmed by Western analysis, while reverse zymography demonstrated TIMP-1 and TIMP-2 along with a putative ovine TIMP-3 in the culture medium from both cell types. The precise role of TIMP in the endometrium remains to be established.
金属蛋白酶组织抑制剂（TIMPs）在组织重塑中发挥重要作用，并且可能与子宫功能有关，包括胚胎着床和胎盘形成。通过对来自经类固醇处理的去卵巢母羊以及处于发情周期和妊娠早期的完整母羊的子宫内膜RNA进行Northern分析，检测了TIMP-1和TIMP-2的mRNA表达。TIMP-1的mRNA（转录本大小为0.9 kb）在去卵巢母羊中表达量很高，雌激素可使其大幅降低，孕酮的降低作用较小。在周期性和妊娠动物中，其丰度在第10天之前一直较低，然后升高，在妊娠动物中一直持续到第20天丰度都很高。在绵羊组织中检测到TIMP-2的两种转录本——3.5 kb的转录本以及丰度更高的1.0 kb的转录本。在去卵巢母羊中，两种转录本的子宫内膜丰度都很低，雌激素处理后其丰度降低，但单独使用孕酮或在雌激素存在下使用孕酮可刺激其丰度升高。TIMP-2 mRNA的丰度在周期的第4天到第14天增加。在妊娠早期，1.0 kb转录本的表达从第4天增加到第12 - 14天，并维持在高水平直至第20天，而3.5 kb转录本在第14天后降低，到第20天降至非常低的水平。与这种TIMP调节表达模式不同，通过Northern分析在任何相同组织中均未检测到proMMP-1和proMMP-3的mRNA。TIMP-1蛋白免疫定位在完整子宫内膜的上皮和基质中，免疫染色强度与mRNA水平相关。在原代培养中，上皮细胞和基质细胞均分泌TIMP-1，通过Western分析证实了其身份，而反向酶谱分析在两种细胞类型的培养基中均显示出TIMP-1和TIMP-2以及一种假定的绵羊TIMP-3。TIMP在子宫内膜中的精确作用仍有待确定。
