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Hughes CHK, Murphy BD. Nuclear receptors: Key regulators of somatic cell functions in the ovulatory process. Mol Aspects Med 2020; 78:100937. [PMID: 33288229 DOI: 10.1016/j.mam.2020.100937] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 12/30/2022]
Abstract
The development of the ovarian follicle to its culmination by ovulation is an essential element of fertility. The final stages of ovarian follicular growth are characterized by granulosa cell proliferation and differentiation, and steroid synthesis under the influence of follicle-stimulating hormone (FSH). The result is a population of granulosa cells poised to respond to the ovulatory surge of luteinizing hormone (LH). Members of the nuclear receptor superfamily of transcription factors play indispensable roles in the regulation of these events. The key regulators of the final stages of follicular growth that precede ovulation from this family include the estrogen receptor beta (ESR2) and the androgen receptor (AR), with additional roles for others, including steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1). Following the LH surge, the mural and cumulus granulosa cells undergo rapid changes that result in expansion of the cumulus layer, and a shift in ovarian steroid hormone biosynthesis from estradiol to progesterone production. The nuclear receptor best associated with these events is LRH-1. Inadequate cumulus expansion is also observed in the absence of AR and ESR2, but not the progesterone receptor (PGR). The terminal stages of ovulation are regulated by PGR, which increases the abundance of the proteases that are directly responsible for rupture. It further regulates the prostaglandins and cytokines associated with the inflammatory-like characteristics of ovulation. LRH-1 regulates PGR, and is also a key regulator of steroidogenesis, cellular proliferation, and cellular migration, and cytoskeletal remodeling. In summary, nuclear receptors are among the panoply of transcriptional regulators with roles in ovulation, and several are necessary for normal ovarian function.
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Affiliation(s)
- Camilla H K Hughes
- Centre de Recherche en Reproduction et Fertilité, Université de Montréal, St-Hyacinthe, Qc, J2S 2M2, Canada
| | - Bruce D Murphy
- Centre de Recherche en Reproduction et Fertilité, Université de Montréal, St-Hyacinthe, Qc, J2S 2M2, Canada.
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Hannon PR, Duffy DM, Rosewell KL, Brännström M, Akin JW, Curry TE. Ovulatory Induction of SCG2 in Human, Nonhuman Primate, and Rodent Granulosa Cells Stimulates Ovarian Angiogenesis. Endocrinology 2018; 159:2447-2458. [PMID: 29648638 PMCID: PMC6287591 DOI: 10.1210/en.2018-00020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/02/2018] [Indexed: 02/06/2023]
Abstract
The luteinizing hormone (LH) surge is essential for ovulation, but the intrafollicular factors induced by LH that mediate ovulatory processes (e.g., angiogenesis) are poorly understood, especially in women. The role of secretogranin II (SCG2) and its cleaved bioactive peptide, secretoneurin (SN), were investigated as potential mediators of ovulation by testing the hypothesis that SCG2/SN is induced in granulosa cells by human chorionic gonadotropin (hCG), via a downstream LH receptor signaling mechanism, and stimulates ovarian angiogenesis. Humans, nonhuman primates, and rodents were treated with hCG in vivo resulting in a significant increase in the messenger RNA and protein levels of SCG2 in granulosa cells collected early during the periovulatory period and just prior to ovulation (humans: 12 to 34 hours; monkeys: 12 to 36 hours; rodents: 4 to 12 hours post-hCG). This induction by hCG was recapitulated in an in vitro culture system utilizing granulosa-lutein cells from in vitro fertilization patients. Using this system, inhibition of downstream LH receptor signaling pathways revealed that the initial induction of SCG2 is regulated, in part, by epidermal growth factor receptor signaling. Further, human ovarian microvascular endothelial cells were treated with SN (1 to 100 ng/mL) and subjected to angiogenesis assays. SN significantly increased endothelial cell migration and new sprout formation, suggesting induction of ovarian angiogenesis. These results establish that SCG2 is increased in granulosa cells across species during the periovulatory period and that SN may mediate ovulatory angiogenesis in the human ovary. These findings provide insight into the regulation of human ovulation and fertility.
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Affiliation(s)
- Patrick R Hannon
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
| | - Diane M Duffy
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk,
Virginia
| | - Katherine L Rosewell
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
| | - Mats Brännström
- Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of
Gothenburg, Gothenburg, Sweden
| | | | - Thomas E Curry
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
- Correspondence: Thomas E. Curry, Jr., PhD, Department of Obstetrics and Gynecology, University of
Kentucky, 800 Rose Street, Room C351, Lexington, Kentucky 40536. E-mail:
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Choi Y, Wilson K, Hannon PR, Rosewell KL, Brännström M, Akin JW, Curry TE, Jo M. Coordinated Regulation Among Progesterone, Prostaglandins, and EGF-Like Factors in Human Ovulatory Follicles. J Clin Endocrinol Metab 2017; 102:1971-1982. [PMID: 28323945 PMCID: PMC5470773 DOI: 10.1210/jc.2016-3153] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/06/2017] [Indexed: 01/12/2023]
Abstract
CONTEXT In animal models, the luteinizing hormone surge increases progesterone (P4) and progesterone receptor (PGR), prostaglandins (PTGs), and epidermal growth factor (EGF)-like factors that play essential roles in ovulation. However, little is known about the expression, regulation, and function of these key ovulatory mediators in humans. OBJECTIVE To determine when and how these key ovulatory mediators are induced after the luteinizing hormone surge in human ovaries. DESIGN AND PARTICIPANTS Timed periovulatory follicles were obtained from cycling women. Granulosa/lutein cells were collected from in vitro fertilization patients. MAIN OUTCOME MEASURES The in vivo and in vitro expression of PGR, PTG synthases and transporters, and EGF-like factors were examined at the level of messenger RNA and protein. PGR binding to specific genes was assessed. P4 and PTGs in conditioned media were measured. RESULTS PGR, PTGS2, and AREG expressions dramatically increased in ovulatory follicles at 12 to 18 hours after human chorionic gonadotropin (hCG). In human granulosa/lutein cell cultures, hCG increased P4 and PTG production and the expression of PGR, specific PTG synthases and transporters, and EGF-like factors, mimicking in vivo expression patterns. Inhibitors for P4/PGR and EGF-signaling pathways reduced hCG-induced increases in PTG production and the expression of EGF-like factors. PGR bound to the PTGS2, PTGES, and SLCO2A1 genes. CONCLUSIONS This report demonstrated the time-dependent induction of PGR, AREG, and PTGS2 in human periovulatory follicles. In vitro studies indicated that collaborative actions of P4/PGR and EGF signaling are required for hCG-induced increases in PTG production and potentiation of EGF signaling in human periovulatory granulosa cells.
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Affiliation(s)
- Yohan Choi
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Kalin Wilson
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Patrick R Hannon
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Katherine L Rosewell
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Mats Brännström
- Department of Obstetrics and Gynecology, University of Gothenburg, 405 30 Gothenburg, Sweden
- Stockholm IVF, 112 81 Stockholm, Sweden
| | - James W Akin
- Bluegrass Fertility Center, Lexington, Kentucky 40503
| | - Thomas E Curry
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Misung Jo
- Department of Obstetrics and Gynecology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
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Liu PP, Chang HM, Cheng JC, Leung PCK. Activin A upregulates PTGS2 expression and increases PGE2 production in human granulosa-lutein cells. Reproduction 2016; 152:655-664. [DOI: 10.1530/rep-16-0262] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/13/2016] [Indexed: 12/20/2022]
Abstract
Activin A is one of the members of transforming growth factor-β superfamily that is expressed in human large luteal cells, and may act in an autocrine/paracrine manner to regulate luteal function. Prostaglandin-endoperoxide synthase 2 (PTGS2) enzyme and its derivative, prostaglandin E2 (PGE2), play significant roles in the regulation of corpus luteum formation and maintenance. To date, whether activin A can induce the expression of PTGS2 and the production of PGE2 in human granulosa-lutein cells is largely unknown. The aim of this study was to examine the effects of activin A on the regulation of PTGS2 expression and PGE2 production in human granulosa-lutein cells, and to investigate the underlying signal transduction mechanisms. In this study, the immortalized (SVOG cells) and primary human granulosa-lutein cells were used as the cell models. A TGF-β/activin type I receptor inhibitor, SB431542 and small interfering RNAs were used to investigate the activin A-induced downstream signaling pathway. We have demonstrated that activin A upregulated the expression of PTGS2 and increased the production of PGE2 via an ACVR1B-mediated SMAD2/3–SMAD4 signaling pathway. Our results suggest that activin A may be involved in the modulation of human corpus luteum formation via the induction of PTGS2 expression and PGE2 production.
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Fang L, Chang HM, Cheng JC, Leung PCK, Sun YP. TGF-β1 induces COX-2 expression and PGE2 production in human granulosa cells through Smad signaling pathways. J Clin Endocrinol Metab 2014; 99:E1217-26. [PMID: 24712567 DOI: 10.1210/jc.2013-4100] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production have been shown to play key roles in the regulation of ovulation. The TGF-β superfamily members are important molecules that regulate many ovarian functions under normal physiological and pathological conditions. TGF-β1 and its receptors are expressed in human granulosa cells. However, to date, whether TGF-β1 can regulate COX-2 expression and PGE2 production, which in turn contribute to the process of ovulation, remains unknown. OBJECTIVE The objective of the study was to investigate the effects of TGF-β1 on COX-2 expression and PGE2 production in human granulosa cells. DESIGN SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with Simian virus 40 large T antigen. SVOG cells were used to investigate the effect of TGF-β1 on COX-2 expression and PGE2 production. SETTING The study was conducted at an academic research center. MAIN OUTCOME MEASURES mRNA and protein levels were examined by RT-quantitative real-time PCR and Western blotting, respectively. The concentrations of PGE2 in the culture medium were measured by an ELISA. RESULTS TGF-β1 treatment induced COX-2 expression and PGE2 production. The inductive effects of TGF-β1 on COX-2 and PGE2 were abolished by the inhibition of TGF-β type I receptor (TβRI). In addition, treatment with TGF-β1 activated phosphorylated mothers against decapentaplegic (Smad)-2 and Smad3 signaling pathways. Inhibition of the Smad signaling pathways by small interfering RNA-mediated approaches attenuated the TGF-β1-induced COX-2 expression and PGE2 production. CONCLUSION TGF-β1 induced PGE2 production by inducing the COX-2 expression through a Smad-dependent signaling pathway in human granulosa cells.
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Affiliation(s)
- Lanlan Fang
- Reproductive Medical Center (L.F., Y.-P.S.), The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China 450052; and Department of Obstetrics and Gynaecology (L.F., H.-M.C., J.-C.C., P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V5Z 4H4
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Nagyova E, Scsukova S, Kalous J, Mlynarcikova A. Effects of RU486 and indomethacin on meiotic maturation, formation of extracellular matrix, and progesterone production by porcine oocyte-cumulus complexes. Domest Anim Endocrinol 2014; 48:7-14. [PMID: 24906923 DOI: 10.1016/j.domaniend.2014.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/13/2014] [Accepted: 01/13/2014] [Indexed: 01/18/2023]
Abstract
This study was designed to determine whether inhibition of either cyclooxygenase-2 (COX-2) by indomethacin or progesterone receptor (PR) by PR antagonist, RU486, affects oocyte maturation, progesterone production, and covalent binding between hyaluronan (HA) and heavy chains of inter-α trypsin inhibitor, as well as expression of cumulus expansion-associated proteins (HA-binding protein, tumor necrosis factor α-induced protein 6, pentraxin 3) in oocyte-cumulus complexes (OCCs). The experiments were based on freshly isolated porcine OCC cultures in which the consequences of PR and COX-2 inhibition on the final processes of oocyte maturation were determined. Granulosa cells (GCs) and OCCs were cultured in medium supplemented with FSH/LH (both 100 ng/mL) in the presence/absence of RU486 or indomethacin. Western blot analysis, (3)H-glucosamine hydrochloride assay, immunofluorescence, and radioimmunoassay were performed. Only treatment with RU486 (25 μM) caused a decrease in the number of oocytes that reached germinal vesicle breakdown and metaphase II stage compared with indomethacin (100 μM) or FSH/LH treatment alone after 44 h. All treated OCCs synthesized an almost equal amount of HA. Heavy chains (of inter-α trypsin inhibitor)-HA covalent complexes were formed during in vitro FSH/LH-stimulated expansion in RU486- or indomethacin-treated OCCs. Follicle-stimulating hormone/LH-induced progesterone production by OCCs was increased in the presence of RU486 after 44 h. In contrast, a decrease of FSH/LH-stimulated progesterone production by GCs was detected in the presence of either RU486 or indomethacin after 72 h. We suggest that the PR-dependent pathway may be involved in the regulation of oocyte maturation. Both PR and COX-2 regulate FSH/LH-stimulated progesterone production by OCCs and GCs.
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Affiliation(s)
- E Nagyova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 27721 Libechov, Czech Republic.
| | - S Scsukova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, 83301 Bratislava, Slovakia
| | - J Kalous
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 27721 Libechov, Czech Republic
| | - A Mlynarcikova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, 83301 Bratislava, Slovakia
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Human chorionic gonadotropin β induces migration and invasion via activating ERK1/2 and MMP-2 in human prostate cancer DU145 cells. PLoS One 2013; 8:e54592. [PMID: 23424616 PMCID: PMC3570544 DOI: 10.1371/journal.pone.0054592] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 12/14/2012] [Indexed: 12/28/2022] Open
Abstract
We previously demonstrated that human chorionic gonadotropin β (hCGβ) induced migration and invasion in human prostate cancer cells. However, the involved molecular mechanisms are unclear. Here, we established a stable prostate cancer cell line overexpressing hCGβ and tested hCGβ-triggered signaling pathways causing cell migration and invasion. ELISA showed that the hCGβ amount secreted into medium increased with culture time after the hCGβ-transfected cells were incubated for 3, 6, 9, 12 and 24 h. More, hCGβ standards promoted MAPK (ERK1/2) phosphorylation and increased MMP-2 expression and activity in both dose- and time-dependent manners in hCGβ non-transfected cells. In addition, hCGβ promoted ERK1/2 phosphorylation and increased MMP-2 expression and activity significantly in hCGβ transfected DU145 cells. Whereas ERK1/2 blocker PD98059 (25 µM) significantly downregulated phosphorylated ERK1/2 and MMP-2. Particularly, hCGβ promoted cell migration and invasion, yet the PD98059 diminished the hCGβ-induced cell motility under those conditions. These results indicated that hCGβ induced cell motility via promoting ERK1/2 phosphorylation and MMP-2 upregulation in human prostate cancer DU145 cells.
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Benzyl butyl phthalate induces necrosis by AhR mediation of CYP1B1 expression in human granulosa cells. Reprod Toxicol 2012; 33:67-75. [DOI: 10.1016/j.reprotox.2011.11.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 10/18/2011] [Accepted: 11/16/2011] [Indexed: 01/03/2023]
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Abe T, Toida D, Satoh H, Yonezawa T, Kawaminami M, Kurusu S. An early single dose of progesterone agonist attenuates endogenous progesterone surge and reduces ovulation rate in immature rat model of induced ovulation. Steroids 2011; 76:1116-25. [PMID: 21600908 DOI: 10.1016/j.steroids.2011.04.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 04/26/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022]
Abstract
Inhibition of preovulatory synthesis and action of progesterone impairs ovulation in rodents. We evaluated effects of supplementation of exogenous progesterone on human chorionic gonadotropin (hCG)-induced ovulatory response in immature rats. Equine CG-primed mature follicles responded to hCG with induction of immunoreactive steroidogenic acute regulatory protein (StAR) mainly in thecal layers and a transient enhancement in progesterone synthesis peaking at 6h after hCG (hCG6h). A single dose of natural progesterone or a synthetic agonist (MP) at hCG0h both decreased ovulation rates in dose-dependent manners. MP was still effective when treated at hCG4h. Treatment with these agents at hCG0h reduced circulating progesterone and thecal expression of StAR at hCG6h. The treatments further attenuated induction of cyclooxygenase (COX)-2 in mural granulosa cells and ovarian prostaglandin (PG) E(2) level at hCG8h. We also found a significant reduction in bromo-deoxyuridine incorporation by mural granulosa cells. Obtained results show that the early treatment with exogenous progesterone agonist caused attenuated amplitude of endogenous progesterone surge, reduced COX-2/PGE(2) system, dysregulated mitosis of granulosa cells, and decreased oocytes release. We suggest that optimal progesterone synthesis and action are an early critical component of hCG-initiated ovulatory cascade that regulates biochemical function of granulosa cells.
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Affiliation(s)
- Tadatsugu Abe
- Laboratory of Veterinary Physiology, Kitasato University School of Veterinary Medicine, Towada, Aomori 034-8628, Japan
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Yerushalmi GM, Maman E, Yung Y, Kedem A, Hourvitz A. Molecular characterization of the human ovulatory cascade-lesson from the IVF/IVM model. J Assist Reprod Genet 2011; 28:509-15. [PMID: 21667102 DOI: 10.1007/s10815-011-9594-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Accepted: 05/24/2011] [Indexed: 11/24/2022] Open
Abstract
AIMS Ovarian follicular development and ovulation in mammals is a complex and highly regulated process. Most advances in the understanding of the ovulatory process have come from animal models. However, translational research in humans is of crucial importance for improving fertility treatment and control. METHODS IVM/IVF procedures allow us to obtain follicular fluid and granulosa cells (GC) from follicles in different developmental stages with and without hCG priming. RESULTS Using the cells and fluids obtained in IVM/IVF procedures allowed us to characterize human ovulatory gene expression during antral folliculogenesis and ovulation, examine gene expression in luteinized and non-luteinized GC in vivo and in vitro and to use cumulus GC genes as biomarkers for oocyte and embryo maturity and competence. CONCLUSION Biological material obtained during IVM/IVF procedures is an important tool to study the human ovulatory cascade and can serve to improve IVM techniques and fertility treatment and control.
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Affiliation(s)
- Gil M Yerushalmi
- IVF Unit, Department of Obstetrics and Gynecology, Chaim Sheba Medical Centre, Tel-Hashomer, Affiliated to the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
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Mori D, Ogino N, Yonezawa T, Kawaminami M, Kurusu S. Anti-ovulatory effects of RU486 and trilostane involve impaired cyclooxygenase-2 expression and mitotic activity of follicular granulosa cells in rats. Prostaglandins Other Lipid Mediat 2011; 94:118-23. [DOI: 10.1016/j.prostaglandins.2011.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 02/07/2011] [Accepted: 02/07/2011] [Indexed: 10/18/2022]
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Shen CJ, Tsai EM, Lee JN, Chen YL, Lee CH, Chan TF. The concentrations of visfatin in the follicular fluids of women undergoing controlled ovarian stimulation are correlated to the number of oocytes retrieved. Fertil Steril 2010; 93:1844-50. [DOI: 10.1016/j.fertnstert.2008.12.090] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2008] [Revised: 12/08/2008] [Accepted: 12/10/2008] [Indexed: 01/30/2023]
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Banerjee P, Fazleabas AT. Endometrial responses to embryonic signals in the primate. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2010; 54:295-302. [PMID: 19876822 PMCID: PMC5070538 DOI: 10.1387/ijdb.082829pb] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The delicate interaction between an embryo and the uterus to initiate implantation and maintain pregnancy is one of the most elegant and fascinating interactions in human biology. Understanding the molecular events of embryo-maternal interaction is of interest to reproductive biologists, clinicians and couples affected by infertility. We have established the baboon as the non-human primate model for studying embryo implantation. Infusion of chorionic gonadotropin (CG), the major embryonic signal of primates, into the uterine cavity of normal cycling baboons during the window of receptivity induces a myriad of morphological, biochemical and molecular changes in the estrogen and progesterone primed endometrium. The luminal epithelium responds by forming plaques, the overall secretory function of the glandular epithelium increases and the stromal response is characterized by induction of alpha-smooth muscle actin (alphaSMA). Cross talk between ovarian and embryonic hormones is evidenced by the fact that these responses are inhibited upon treatment with a progesterone receptor antagonist. CG signals principally through the seven transmembrane LH/CG G-protein coupled receptor, and activates a mitogen activated protein kinase pathway in the endometrial epithelium that is unique and independent of all the classical signaling pathways. In the stromal compartment, CG both rescues stromal fibroblasts from their apoptotic demise and also differentiates them into the decidualized phenotype. We propose that stromal cell survival and differentiation is mediated by a critical modulator of cell fate, Notch-1. Thus, CG is an important embryonic signal which modulates communication between the embryo and the endometrium and induces changes that are critical to successful implantation.
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Affiliation(s)
- Prajna Banerjee
- Department of Physiology and Biophysics, University of Illinois, Chicago, IL, USA
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Dhillon JK, Su X, Liu Z. Effects of RU486 on cyclooxygenase-2 gene expression, prostaglandin F2alpha synthesis and ovulation in Xenopus laevis. Gen Comp Endocrinol 2010; 165:78-82. [PMID: 19524582 DOI: 10.1016/j.ygcen.2009.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 05/20/2009] [Accepted: 06/08/2009] [Indexed: 11/18/2022]
Abstract
RU486 is a synthetic analog of progesterone and functions as a progesterone receptor antagonist. It binds to the progesterone receptor to prevent progesterone from occupying its receptor in many cellular systems. Early studies from our laboratory have shown that in Xenopus laevis ovarian follicles progesterone stimulates the expression of cyclooxygenase-2 (COX-2) gene which leads to a rapid increase in the production of prostaglandin F2alpha (PGF2alpha) and subsequent ovulation. In this study, we examined the effect of RU486 on the synthesis of COX-2 mRNA, production of PGF2alpha and ovulation in X. laevis. Ovarian tissue fragments were primed with human chorionic gonadotropin (hCG) and then incubated with progesterone (P4) alone or in the presence of varying concentrations of RU486 over a period of 12h. After the incubation ovulated oocytes were counted, COX-2 expression and synthesis of PGF2alpha were measured. Results demonstrated that RU486 attenuated the expression of COX-2 gene, reduced the synthesis of PGF2alpha, and inhibited ovulation in a dose-dependent manner. This finding suggests that progesterone receptor is an important regulator in the progesterone-cyclooxygenase-prostaglandin-mediated ovulation in amphibians.
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Affiliation(s)
- Jasvinder K Dhillon
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA
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Banerjee P, Sapru K, Strakova Z, Fazleabas AT. Chorionic gonadotropin regulates prostaglandin E synthase via a phosphatidylinositol 3-kinase-extracellular regulatory kinase pathway in a human endometrial epithelial cell line: implications for endometrial responses for embryo implantation. Endocrinology 2009; 150:4326-37. [PMID: 19556419 PMCID: PMC2736085 DOI: 10.1210/en.2009-0394] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 06/12/2009] [Indexed: 01/15/2023]
Abstract
Successful implantation necessitates modulation of the uterine environment by the embryo for a specific period of time during the menstrual cycle. Infusion of chorionic gonadotropin (CG) into the oviducts of baboons to mimic embryo transit induces a myriad of morphological, biochemical, and molecular changes in the endometrium. Endometrial epithelial cells from both baboons and humans when stimulated by CG in vitro, activates a cAMP-independent MAPK pathway leading to prostaglandin E(2) (PGE(2)) synthesis. This study shows that in the human endometrial cell line, HES, CG, acting via its G-protein coupled receptor, phosphorylates protein kinase B, c-Raf, and ERK1/2 in a phosphatidylinositol 3-kinase (PI3K)-dependent manner. Furthermore, ERK1/2 phosphorylation is independent of the signaling paradigms of Galpha(s), Galpha(I), and epidermal growth factor receptor (EGFR) transactivation, typical of gonadal cells, indicating an alternative signaling pattern in the endometrium. After phosphorylation by CG, ERK1/2 translocates to the nucleus in a time-dependent manner. Downstream of ERK1/2, CG activates the nuclear transcription factor, Elk1, also in a PI3K-MAPK-dependent manner. Lastly, we show that in HES cells, this pathway regulates the expression of the microsomal enzyme PGE(2) synthase (mPTGES), a terminal prostanoid synthase responsible for PGE(2) synthesis. CG regulates the mPTGES promoter and also induces mPTGES synthesis in HES cells via the PI3K-ERK1/2 pathway. We suggest that this alternative PI3K-ERK-Elk pathway activated by CG regulates prostaglandin production by the endometrial epithelium and serves as an early trigger to prepare the endometrium for implantation.
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Affiliation(s)
- Prajna Banerjee
- Department of Physiology and Biophysics, University of Illinois, Chicago, Illinois 60612, USA
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