Zimmermann Gerolf, Ackermann Wilfried, Alexander Henry
Department of Obstetrics and Gynaecology, University of Leipzig, Leipzig, Germany.
Biol Reprod. 2009 May;80(5):1053-65. doi: 10.1095/biolreprod.108.069575. Epub 2009 Jan 21.
The objective of this study was to determine whether beta human chorionic gonadotropin (hCG) (CGB) subunits and alpha hCG (CGA) subunits are expressed and the hCG dimer is produced in normal human cyclic endometrium. Endometrial specimens were collected for histological dating from women undergoing treatment in our division of human reproduction. RNA from normal secretory endometrium was extracted, and CGB and CGA gene expression was assessed by semiquantitative PCR. Adequate secretory endometrial specimens were homogenized using protease inhibitors. Proteins present in the supernatant were separated electrophoretically, and molecular hCG isoforms were detected by Western blot. The supernatant hCG concentrations were measured by ELISA. We characterized hCG and leukocytes in endometrial specimens by immunohistochemistry. Uterine flushing was performed to confirm endometrial hCG secretion into the uterine fluid. A full-length CGB mRNA encompassing the exon 1 promoter region and the structure exons 2 and 3 (including the C-terminal peptide) was expressed in normal secretory endometrial specimens (similar to CGA) during the early secretory phase of the menstrual cycle, up to an optimum at the midsecretory to late secretory phases. In homogenate supernatants obtained from normal secretory endometrium, hormone concentrations of dimeric hCG were approximately 5 mU per 10 mg of tissue, compared with considerably smaller concentrations of corresponding single free CGB subunit. Single chains of CGB, CGA, and dimeric molecular hCG isoforms were found in endometrial specimens by Western blot. Glandular endometrial hCG production is demonstrated immunohistochemically, with an increase toward the late secretory phase vs. the early secretory phase of the normal secretory menstrual cycle. However, glandular hCG release is diminished or absent in the dyssynchronous or missing endometrial secretory transformation. Endogenous endometrial hCG may be important for implantation and maintenance of pregnancy.
本研究的目的是确定在正常人类周期性子宫内膜中是否表达β人绒毛膜促性腺激素（hCG）（CGB）亚基和α hCG（CGA）亚基，以及是否产生hCG二聚体。从我院人类生殖科接受治疗的女性中收集子宫内膜标本进行组织学分期。提取正常分泌期子宫内膜的RNA，通过半定量PCR评估CGB和CGA基因表达。使用蛋白酶抑制剂对充分的分泌期子宫内膜标本进行匀浆。对上清液中的蛋白质进行电泳分离，通过蛋白质印迹法检测分子hCG异构体。通过酶联免疫吸附测定法测量上清液hCG浓度。我们通过免疫组织化学对子宫内膜标本中的hCG和白细胞进行了表征。进行子宫灌洗以确认子宫内膜hCG分泌到子宫液中。在月经周期的早分泌期，正常分泌期子宫内膜标本中表达了包含外显子1启动子区域以及外显子2和3结构（包括C末端肽）的全长CGB mRNA（类似于CGA），在分泌中期至晚期达到最佳水平。在从正常分泌期子宫内膜获得的匀浆上清液中，二聚体hCG的激素浓度约为每10毫克组织5毫国际单位，而相应的单个游离CGB亚基的浓度则小得多。通过蛋白质印迹法在子宫内膜标本中发现了CGB、CGA的单链以及二聚体分子hCG异构体。免疫组织化学显示腺性子宫内膜产生hCG，在正常分泌期月经周期的晚分泌期相对于早分泌期有所增加。然而，在不同步或缺失的子宫内膜分泌转化中，腺性hCG释放减少或缺失。内源性子宫内膜hCG可能对妊娠的着床和维持很重要。
