Kamijo T, Rajabi M R, Mizunuma H, Ibuki Y
Department of Obstetrics and Gynecology, University of Medicine and Dentistry of New Jersey, Newark 07103, USA.
Mol Hum Reprod. 1998 Oct;4(10):990-8. doi: 10.1093/molehr/4.10.990.
During embryo implantation, apoptosis is observed morphologically at the implantation site of endometrium. The objectives of this study were to demonstrate biochemical evidence of apoptosis and quantitative assessment of DNA fragmentation in uterine epithelial cells using a mouse implantation model, and to investigate the autocrine/paracrine regulation of apoptosis in uterine epithelial cells during blastocyst outgrowth. Blastocysts from day 4 pregnant mice were cultured on uterine epithelial cells for 96 h. Uterine epithelial cells dislodged by trophoblasts in endometrium-trophoblast unit demonstrated morphological features of apoptosis by Acridine Orange staining. Electrophoresis demonstrated DNA ladder and DNA fragmentation by enzyme-linked immunosorbent assay markedly increased after 48 h period of incubation. Apoptosis increased in an exponential way in accordance with trophoblast outgrowth. In addition, DNA fragmentation was shown in the epithelial cells by adding embryo-conditioned medium (CM) and the effect of embryo CM on apoptosis was significantly inhibited by anti-transforming growth factor (TGF)-beta antibody. Delayed outgrowth was observed after 48 h of incubation in the blastocysts cultured with anti-TGF-beta antibody. These results suggest there is autocrine/paracrine regulation of apoptosis in uterine epithelial cells at mouse embryo implantation and that TGF-beta might play an important role in the occurrence of apoptosis in the endometrium-trophoblast unit.
在胚胎植入过程中，在子宫内膜的植入部位可通过形态学观察到细胞凋亡。本研究的目的是利用小鼠植入模型证明子宫上皮细胞凋亡的生化证据并对DNA片段化进行定量评估，以及研究胚泡孵出期间子宫上皮细胞凋亡的自分泌/旁分泌调节。将妊娠第4天小鼠的胚泡在子宫上皮细胞上培养96小时。在子宫内膜-滋养层单元中被滋养层细胞分离的子宫上皮细胞经吖啶橙染色显示出凋亡的形态学特征。电泳显示DNA梯形条带，并且在孵育48小时后通过酶联免疫吸附测定法检测到的DNA片段化明显增加。随着滋养层的孵出，细胞凋亡呈指数方式增加。此外，添加胚胎条件培养基（CM）后上皮细胞出现DNA片段化，并且抗转化生长因子（TGF）-β抗体可显著抑制胚胎CM对细胞凋亡的作用。在用抗TGF-β抗体培养的胚泡中，孵育48小时后观察到孵出延迟。这些结果表明，在小鼠胚胎植入时子宫上皮细胞凋亡存在自分泌/旁分泌调节，并且TGF-β可能在子宫内膜-滋养层单元细胞凋亡的发生中起重要作用。
