Semin Reprod Med 2001; 19(1): 037-048
DOI: 10.1055/s-2001-13909
Copyright © 2001 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel.: +1(212) 584-4662

On the Role of Human Chorionic Gonadotropin (hCG) in the Embryo-Endometrial Microenvironment: Implications for Differentiation and Implantation

P. Licht, V. Russu, L. Wildt
  • Department of Obstetrics and Gynecology, Division of Gynecological Endocrinology and Reproductive Medicine, University of Erlangen-Nürnberg, Erlangen, Germany
Further Information

Publication History

Publication Date:
31 December 2001 (online)

ABSTRACT

Recent evidence suggests that human chorionic gonadotropin (hCG), in addition to its well-known endocrine effects on the corpus luteum, may act as a growth and differentiation factor during pregnancy. According to experimental results, its mode of action may be divided into three sequential phases. During the first phase, which begins at the blastocyst stage and lasts until the occurrence in the serum, hCG acts preferentially in a juxtacrine manner. We have used an intrauterine microdialysis system developed in our laboratory to administer low concentrations of hCG to the endometrium of women in the luteal phase of the menstrual cycle. HCG administration provoked profound effects on paracrine parameters of differentiation (IGFBP-1, prolactin) and implantation (LIF, M-CSF). VEGF, a cytokine important for neoangiogenesis, was significantly stimulated by hCG (P <.01), suggesting a role for hCG in the control of endometrial vascularization and placentation. The investigation of endometrial parameters of tissue remodeling revealed a significant increase of MMP-9 (P <.05) but not of TIMP-1 following hCG infusion. The second, endocrine, phase of hCG action is marked by the appearance of hCG in the maternal serum. Rising systemic hCG levels cause a very rapid elevation of serum progesterone reflecting the rescue of the corpus luteum. Other endocrine functions of hCG include its intrinsic thyrotropic activity as well as modulation of fetal testicular, ovarian, and adrenal function. The third phase may be characterized by the expression of full-length hCG/LH receptors on the trophoblasts themselves. Before the ninth week of gestation, human villous trophoblasts express a truncated hCG/LH receptor isoform (50 kDa) and are probably not responsive to hCG. Later, the expression pattern is switched to the full-length receptor (80 kDa), allowing hCG also to modulate the differentiation of the trophoblasts themselves. A special feature is the self-regulation of hCG biosynthesis that may in part explain the unique secretion profile of the hormone with peak levels during the first trimester followed by a rapid decline after the tenth week of gestation. In summary, hCG seems to have a variety of local and systemic functions in and outside the embryo-endometrial microenvironment.

REFERENCES

  • 1 Wilcox A J, Baird D D, Weinberg C R. Time of implantation of the conceptus and loss of pregnancy.  N Engl J Med . 1999;  340 1796-1799
  • 2 Braude P, Pelham H, Flach G, Lobatto R. Post-transcriptional control in the early mouse embryo.  Nature . 1979;  282 102-105
  • 3 Mark M, Rijli F M, Chambon P. Homeobox genes in embryogenesis and pathogenesis.  Pediatr Res . 1997;  42 421-429
  • 4 Stewart C L, Kaspar P, Brunet L J. Blastocyst implantation depends on maternal expression of leukemia inhibitory factor.  Nature . 1992;  359 76-79
  • 5 Satokata I, Benson G, Maas R. Sexually dimorphic sterility phenotypes in Hoxa-10-deficient mice.  Nature . 1995;  374 460-463
  • 6 Robb L, Li R, Hartley L, Nandurkar H H, Koentgen F, Begley C G. Infertility in female mice lacking the receptor for interleukin 11 is due to a defective uterine response to implantation.  Nat Med . 1998;  4 303-308
  • 7 Pollard J W, Hunt J S, Wiktor-Jedrzejczak W, Stanley E R. A pregnancy defect in the osteopetrotic (op/op) mouse demonstrates the requirement of CSF-1 in female infertility.  Dev Biol . 1991;  148 273-283
  • 8 Harvey M B, Leco K J, Arcellana-Panlilie M Y, Zhang X, Edwards D R, Schultz G A. Roles of growth factors during peri-implantation development.  Mol Hum Reprod . 1995;  10 712-718
  • 9 Simon C, Frances A, Piquette G N. Embryonic implantation in mice is blocked by interleukin-1 receptor antagonist.  Endocrinology . 1994;  134 521-528
  • 10 Hoshina M, Boothby M, Hussa R, Patillo R, Camel H M, Boime I. Linkage of human chorionic gonadotrophin and placental lactogen biosynthesis to trophoblast differentiation and tumorigenesis.  Placenta . 1985;  6 163-172
  • 11 Bonduelle M L, Dodd R, Liebaers I, Van Steirteghem A, Williamson R, Akhurst R. Chorionic gonadotrophin-beta mRNA, a trophoblast marker, is expressed in human 8-cell embryos derived from tripronucleate zygotes.  Hum Reprod . 1988;  3 909-914
  • 12 Shi Q J, Lei Z M, Rao C V, Lin J. Novel role of human chorionic gonadotropin in differentiation of human cytotrophoblasts.  Endocrinology . 1993;  132 1387-1395
  • 13 Cronier L, Bastide B, Herve J C, Deleze J, Malassine A. Gap junctional communication during human trophoblast differentiation: influence of human chorionic gonadotropin.  Endocrinology . 1994;  135 402-408
  • 14 Licht P, Cao H, Lei Z M, Rao C V, Merz W E. Novel self-regulation of human chorionic gonadotropin biosynthesis in term pregnancy human placenta.  Endocrinology . 1993;  133 3014-1025
  • 15 Licht P, Cao H, Zuo J. Lack of self-regulation of human chorionic gonadotropin biosynthesis in human choriocarcinoma cells.  J Clin Endocrinol Metab . 1994;  78 1188-1194
  • 16 Tao Y X, Lei Z M, Hofmann G E, Rao C V. Human intermediate trophoblasts express human chorionic gonadotropin/ luteinizing hormone receptor gene.  Biol Reprod . 1995;  53 899-904
  • 17 Yagel S, Geva T E, Soloman H. High levels of human chorionic gonadotrophin retard first trimester trophoblast invasion in vitro by decreasing urokinase plasminogen activator and collagenase activities.  J Clin Endocrinol Metab . 1993;  77 1506-1511
  • 18 Zygmunt M, Hahn D, Munstedt K, Bishof P, Lang U. Invasion of cytotrophoblastic JEG-3 cells is stimulated by hCG in vitro.  Placenta . 1998;  19 587-593
  • 19 Licht P, Wildt L. Gonadal and extragonadal receptors for human chorionic gonadotropin (hCG) and luteinizing hormone (LH).  Ass Reprod Rev . 1998;  8 152-172
  • 20 Merz W E, Erlewein C, Licht P, Harbarth P. The secretion of human chorionic gonadotropin as well as the α- and β-messenger ribonucleic acid levels are stimulated by exogenous gonadoliberin pulses applied to first trimester placenta in a superfusion tissue culture system.  J Clin Endocrinol Metab . 1991;  73 84-92
  • 21 Licht P, Harbarth P, Merz W E. Evidence for a modulation of human chorionic gonadotropin (hCG) subunit messenger ribonucleic acid levels and hCG secretion by γ-aminobutyric acid (GABA) in human first trimester placenta in vitro.  Endocrinology . 1992;  130 490-496
  • 22 Benveniste R, Speeg K V, Carpenter G, Cohen S, Lindner J, Rabinowitz D. Epidermal growth factor stimulates secretion of human chorionic gonadotropin by cultured human choriocarcinoma cells.  J Clin Endocrinol Metab . 1978;  46 169-171
  • 23 Merz W E. Biosynthesis of human chorionic gonadotropin: a review.  Eur J Endocrinol . 1996;  135 269-284
  • 24 Lei Z M, Toth P, Rao C V, Pridham D D. Novel co-expression of human chorionic gonadotropin (hCG)/luteinizing hormone receptors and their ligand hCG in human fallopian tubes.  J Clin Endocrinol Metab . 1993;  77 863-872
  • 25 Reshef E, Lei Z M, Rao C V, Pridham D D, Chegini N, Luborsky J L. The presence of gonadotropin receptors in non-pregnant human uterus, human placenta, fetal membranes, and decidua.  J Clin Endocrinol Metab . 1990;  70 421-429
  • 26 Környei J, Lei Z M, Rao C V. Human myometrial smooth muscle cells are novel targets of direct regulation by human chorionic gonadotropin.  Biol Reprod . 1993;  49 1149-1157
  • 27 Ziecik A J, Stanchev P D, Tilton J E. Evidence for the presence of luteinizing hormone/human chorionic gonadotropin binding sites in the porcine uterus.  Endocrinology . 1986;  119 1159-1163
  • 28 Jensen J D, Odell W D. Identification of LH/hCG receptors in the rabbit uterus.  Proc Soc Exp Biol Med . 1988;  189 28-30
  • 29 Bonnamy P J, Benhaim A, Leymarie P. Estrous-cycle related changes in high affinity luteinizing hormone/human chorionic gonadotropin binding sites in the rat uterus.  Endocrinology . 1990;  126 421-430
  • 30 Bonnamy P J, Benhaim A, Leymarie P. Uterine luteinizing hormone/human chorionic gonadotropin binding sites in the early pregnant rat uterus: evidence for a total occupancy in the peri-implantation period.  Endocrinology . 1993;  132 1240-1246
  • 31 Mukherjee D, Manna P R, Bhattacharya S. Functional relevance of luteinizing hormone receptors in the mouse uterus.  Eur J Endocrinol . 1994;  131 103-108
  • 32 Freidman S, Gurevich M, Shemesh M. Bovine cyclic endometrium contains high-affinity luteinizing hormone/ human chorionic gonadotropin binding sites.  Biol Reprod . 1995;  52 1020-1026
  • 33 Lin J, Lei Z M, Lojun S, Rao C V, Satjaswaroop P G, Day T G. Increased expression of luteinizing hormone/human chorionic gonadotropin receptor gene in human endometrial carcinomas.  J Clin Endocrinol Metab . 1994;  79 1483-1491
  • 34 Han S W, Lei Z M, Rao C V. Treatment of human endometrial stroma cells with chorionic gonadotropin promotes their morphological and functional differentiation into decidua.  Mol Cell Endocrinol . 1999;  147 7-16
  • 35 Han S W, Lei Z M, Rao C V. Up-regulation of cyclooxygenase-2 gene expression by chorionic gonadotropin during the differentiation of human endometrial stromal cells into decidua.  Endocrinology . 1996;  137 1791-1797
  • 36 Han S W, Lei Z M, Rao C V. Homologous down-regulation of luteinizing hormone/chorionic gonadotropin receptors by increasing the degradation of receptor transcripts in human endometrial stromal cells.  Biol Reprod . 1997;  57 158-164
  • 37 Fazleabas A T, Donnelly K M, Srinivasan S, Fortman J D, Miller J B. Modulation of the baboon (Papio anubis) uterine endometrium by chorionic gonadotrophin during the period of uterine receptivity.  Proc Natl Acad Sci U S A . 1999;  96 2543-2548
  • 38 Licht P, Lösch A, Dittrich R, Neuwinger J, Siebzehnrübl E, Wildt L. Novel insights into human endometrial paracrinology and feto-maternal communication by intrauterine microdialysis.  Hum Reprod Update . 1998;  4 532-538
  • 39 Irving J A, Lala P K. Functional role of cell surface integrins on human trophoblast cell migration: regulation by a TGF-beta, IGF-II, and IGFBP-1.  Exp Cell Res . 1995;  21 419-427
  • 40 Hamilton G S, Lysiak J J, Han V K, Lala P K. Autocrine-paracrine regulation of human trophoblast invasiveness by insulin-like growth factor (IGF)-II and IGF-binding protein (IGFBP)-1.  Exp Cell Res . 1998;  244 147-156
  • 41 Bishof P, Meisser A, Campana A, Tseng L. Effects of decidua-conditioned medium and insulin-like growth factor binding protein-1 on trophoblastic matrix metalloproteinases and their inhibitors.  Placenta . 1998;  19 457-464
  • 42 Neulen J, Yan Z, Raczek S. HCG-dependent expression of vascular endothelial growth factor/vascular permeability factor in human granulosa cells.  J Clin Endocrinol Metab . 1995;  80 1967-1971
  • 43 Owens O M, Ryan K J, Tulchinsky D. Episodic secretion of human chorionic gonadotropin in early pregnancy.  J Clin Endocrinol Metab . 1981;  53 1307-1309
  • 44 Bischof P, Campana A. A model for implantation of the human blastocyst and early placentation.  Hum Reprod Update . 1996;  2 262-270
  • 45 Tomer Y, Huber G K, Davies T F. Human chorionic gonadotropin (hCG) interacts directly with recombinant human TSH receptors.  J Clin Endocrinol Metab . 1992;  74 1477-1479
  • 46 Saez J M. Leydig cells: endocrine, paracrine, and autocrine regulation.  Endocrine Rev . 1994;  15 574-626
  • 47 Lei Z M, Rao C V, Kornyei J, Licht P, Hiatt E S. Novel expression of human chorionic gonadotropin/luteinizing hormone receptor gene in brain.  Endocrinology . 1993;  132 2262-2270
  • 48 Toth P, Lukacs H, Hiatt E S, Reid K H, Iyer V, Rao C V. Administration of human chorionic gonadotropin affects sleep-wake phases and other associated behaviours in cycling female rats.  Brain Res . 1994;  654 181-190
    >