Lei H, Furth E E, Kalluri R, Wakenell P, Kallen C B, Jeffrey J J, Leboy P S, Strauss J F
Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, University of Pennsylvania Medical Center, Philadelphia 19104, USA.
Biol Reprod. 1999 Jan;60(1):183-9. doi: 10.1095/biolreprod60.1.183.
The membranes surrounding the chick embryo undergo striking morphological changes before hatching, which include structural degradation of the allantoic membrane. The fibrillar collagen content of the membranes declined by embryonic day (ED) 20 (the day of hatching). By ED 19, a 55-kDa matrix metalloproteinase (MMP) activity appeared in the extraembryonic fluid, and by ED 20 there was substantial 55-kDa MMP activity in embryonic membrane extracts. Reverse transcription-polymerase chain reaction was employed to clone a partial cDNA representing the chicken homologue of MMP-13, a 55- to 57-kDa enzyme. MMP-13 mRNA dramatically increased in abundance in embryonic membranes by ED 19, reaching a peak on ED 20. Introduction of the MMP inhibitor batimastat into the extraembryonic fluid prevented the structural changes in the embryonic membranes before hatching. We conclude that, like mammalian fetal membranes, chick embryonic membranes undergo terminal remodeling before hatching, in part as a result of increased MMP activity. The chicken egg system represents a novel in vivo model for exploring biochemical events leading to embryonic membrane remodeling prior to birth and to test inhibitors of MMPs for their ability to prevent collagenolysis and fetal membrane rupture.
围绕鸡胚的膜在孵化前会发生显著的形态变化，其中包括尿囊膜的结构降解。这些膜中的纤维状胶原蛋白含量在胚胎发育第20天（孵化日）时下降。到胚胎发育第19天，一种55 kDa的基质金属蛋白酶（MMP）活性出现在胚外液中，到胚胎发育第20天，胚胎膜提取物中出现大量55 kDa的MMP活性。采用逆转录-聚合酶链反应克隆了一个代表MMP-13（一种55至57 kDa的酶）鸡同源物的部分cDNA。到胚胎发育第19天，MMP-13 mRNA在胚胎膜中的丰度显著增加，在胚胎发育第20天达到峰值。将MMP抑制剂batimastat引入胚外液可防止孵化前胚胎膜的结构变化。我们得出结论，与哺乳动物胎膜一样，鸡胚胎膜在孵化前经历终末重塑，部分原因是MMP活性增加。鸡蛋系统代表了一种新型的体内模型，用于探索导致出生前胚胎膜重塑的生化事件，并测试MMP抑制剂防止胶原溶解和胎膜破裂的能力。
