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Fierro S, Viñoles C, Olivera-Muzante J. Concentrations of steroid hormones, estrous, ovarian and reproductive responses in sheep estrous synchronized with different prostaglandin-based protocols. Anim Reprod Sci 2016; 167:74-82. [DOI: 10.1016/j.anireprosci.2016.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 02/07/2016] [Accepted: 02/08/2016] [Indexed: 01/27/2023]
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2
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Han KH, Kim MK, Kim HS, Chung HH, Song YS. Protective Effect of Progesterone during Pregnancy against Ovarian Cancer. J Cancer Prev 2014; 18:113-22. [PMID: 25337537 PMCID: PMC4189458 DOI: 10.15430/jcp.2013.18.2.113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 12/31/2022] Open
Abstract
There have been several epidemiologic studies supporting the protective role of pregnancy, although the mechanism is not clear. High level of progesterone, which is crucial in maintaining pregnancy, has been supposed to be one of the causative factors. Progesterone is produced at the corpus luteum in the early pregnancy and the placenta in the late pregnancy period. In several experimental studies, progesterone was reported to induce apoptosis of ovarian cancer cells through intrinsic and extrinsic pathways. In addition, progesterone has been shown to exert its anticancer effect through genomic and non-genomic action. The objective of this review is to discuss the protective mechanism of pregnancy against ovarian cancer focusing on the steroid hormone, progesterone.
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Affiliation(s)
- Kyung Hee Han
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine
| | - Mi-Kyung Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine
| | - Hee Seung Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine
| | - Hyun Hoon Chung
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine
| | - Yong Sang Song
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine ; Cancer Research Institute, Seoul National University College of Medicine ; Major in Biomodulation, World Class University, Seoul National University, Seoul, Korea
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3
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Xiang J, Wang Y, Su K, Liu M, Hu PC, Ma T, Li JX, Wei L, Zheng Z, Yang F. Ritonavir binds to and downregulates estrogen receptors: molecular mechanism of promoting early atherosclerosis. Exp Cell Res 2014; 327:318-30. [PMID: 25017101 DOI: 10.1016/j.yexcr.2014.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/29/2014] [Accepted: 07/01/2014] [Indexed: 11/16/2022]
Abstract
Estrogenic actions are closely related to cardiovascular disease. Ritonavir (RTV), a human immunodeficiency virus (HIV) protease inhibitor, induces atherosclerosis in an estrogen-related manner. However, how RTV induce pathological phenotypes through estrogen pathway remains unclear. In this study, we found that RTV increases thickness of coronary artery walls of Sprague Dawley rats and plasma free fatty acids (FFA) levels. In addition, RTV could induce foam cell formation, downregulate both estrogen receptor α (ERα) and ERβ expression, upregulate G protein-coupled estrogen receptor (GPER) expression, and all of them could be partially blocked by 17β-estradiol (E2), suggesting RTV acts as an antagonist for E2. Computational modeling shows a similar interaction with ERα between RTV and 2-aryl indoles, which are highly subtype-selective ligands for ERα. We also found that RTV directly bound to ERα and selectively inhibited the nuclear localization of ERα, and residue Leu536 in the hydrophobic core of ligand binding domain (LBD) was essential for the interaction with RTV. In addition, RTV did not change the secondary structure of ERα-LBD like E2, which explained how ERα lost the capacity of nuclear translocation under the treatment of RTV. All of the evidences suggest that ritonavir acts as an antagonist for 17β-estradiol in regulating α subtype estrogen receptor function and early events of atherosclerosis.
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Affiliation(s)
- Jin Xiang
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, School of Pharmaceutical Science, Wuhan University, Wuhan 430071, PR China
| | - Ying Wang
- Department of Pathophysiology, School of Medicine, Wuhan University, Wuhan 430071, PR China
| | - Ke Su
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Min Liu
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, School of Pharmaceutical Science, Wuhan University, Wuhan 430071, PR China
| | - Peng-Chao Hu
- Department of Pathophysiology, School of Medicine, Wuhan University, Wuhan 430071, PR China
| | - Tian Ma
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, School of Pharmaceutical Science, Wuhan University, Wuhan 430071, PR China
| | - Jia-Xi Li
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, School of Pharmaceutical Science, Wuhan University, Wuhan 430071, PR China
| | - Lei Wei
- Department of Pathophysiology, School of Medicine, Wuhan University, Wuhan 430071, PR China
| | - Zhongliang Zheng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China.
| | - Fang Yang
- Department of Physiology, School of Medicine, Wuhan University, Wuhan 430071, PR China.
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The expression of ERα, OTR, cPLA2, COX-2, and PPARγ in the cervix of the ewe during the estrous cycle. Theriogenology 2013; 79:40-7. [DOI: 10.1016/j.theriogenology.2012.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 08/30/2012] [Accepted: 09/06/2012] [Indexed: 11/18/2022]
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5
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Rodríguez-Piñón M, Tasende C, Garófalo EG. Expression of genes for oestrogen and progesterone receptors in the cervix of anoestrous ewes treated with gonadotrophin releasing hormone with or without progesterone priming. Anim Reprod Sci 2011; 126:50-6. [PMID: 21601386 DOI: 10.1016/j.anireprosci.2011.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/30/2011] [Accepted: 04/14/2011] [Indexed: 10/18/2022]
Abstract
The aim was to determine the oestrogens receptor alpha (ERα) mRNA and the binding capacity of oestrogens (ER) and progesterone receptor (PR) in the cervix of anoestrous ewes treated with gonadotrophin-releasing hormone (GnRH) with or without progesterone (P) priming, at the expected time of induced ovulation and early luteal phase. In Experiment 1, ewes were treated with P for 10 days (n=4), with nine micro-doses of GnRH followed by a GnRH bolus injection (n=4), or with P plus GnRH treatments (n=3), and tissues were harvested either without treatment (n=4), when P was removed, or 24h after the GnRH bolus injection. In Experiment 2, ewes were treated with the same GnRH or P plus GnRH treatments and tissues were harvested on Day 1 (n=12) or Day 5 (n=10) after the GnRH bolus injection. In the cranial cervix, the P treatment decreased and the GnRH treatment (after P treatment) increased the ERα mRNA, ER and PR concentrations (P<0.002). The ERα mRNA and ER concentrations were greater on Day 1, than on Day 5 in P plus GnRH treated ewes (P<0.0005). In the caudal cervix, lesser ERα mRNA, ER and PR concentrations than cranial cervix were found (P<0.0001). In conclusion, the ERα transcriptional activity and ER and PR binding capacity were strongly influenced by P and/or GnRH treatments in the cranial cervix, while the steroid receptors binding capacity remained unchanged in the caudal cervix of anoestrous ewes at the expected time of induced ovulation and early luteal phase.
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Affiliation(s)
- M Rodríguez-Piñón
- Biochemistry, Department of Molecular and Cellular Biology, Faculty of Veterinary, Montevideo, Uruguay.
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6
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Chen JC, Frankshun AL, Wiley AA, Miller DJ, Welch KA, Ho TY, Bartol FF, Bagnell CA. Milk-borne lactocrine-acting factors affect gene expression patterns in the developing neonatal porcine uterus. Reproduction 2011; 141:675-83. [DOI: 10.1530/rep-10-0320] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lactocrine communication of milk-borne bioactive factors (MbFs) from mother to offspring through nursing can affect neonatal development with lasting consequences. Relaxin (RLX), a lactocrine-active peptide found in porcine colostrum, stimulates estrogen receptor-α (ESR1) expression required for uterine development shortly after birth (postnatal day=PND 0). Whether other MbFs or cooperative lactocrine mechanisms affect the neonatal uterine developmental program is unknown. To determine the effects of age, nursing, and exogenous RLX on gene expression associated with uterine development, gilts (n=4–5/group) were assigned to nursead libitumor to receive milk replacer, with or without exogenous RLX (20 μg/kg BW i.m./6 h for 48 h), from birth to PND 2 when uteri were collected. Body weight and uterine weight increased (P<0.05) similarly from birth to PND 2 in all gilts. However, colostrum consumption was required for normal uterine ESR1, vascular endothelial growth factor (VEGFA), matrix metalloproteinase 9 (MMP9), and RLX receptor (RXFP1) protein and/or transcript expression on PND 2. Uterine ESR1, VEGFA, and MMP9 protein levels were below (P<0.01) the assay sensitivity in replacer-fed gilts. Supplemental RLX increased (P<0.05) uterine ESR1 protein and mRNA in nursed gilts, as well as VEGFA protein in nursed andVEGFAmRNA in both nursed and replacer-fed gilts. RLX treatment did not affect uterineMMP9mRNA levels. When compared with replacer-fed gilts on PND 2, uterineRXFP1mRNA was reduced (P<0.05) in nursed gilts and in RLX-supplemented replacer-fed gilts. These results constitute the first evidence that establishment of the neonatal porcine uterine developmental program requires maternal lactocrine support.
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7
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Bagamasbad P, Denver RJ. Mechanisms and significance of nuclear receptor auto- and cross-regulation. Gen Comp Endocrinol 2011; 170:3-17. [PMID: 20338175 PMCID: PMC2911511 DOI: 10.1016/j.ygcen.2010.03.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/02/2010] [Accepted: 03/19/2010] [Indexed: 12/14/2022]
Abstract
The number of functional hormone receptors expressed by a cell in large part determines its responsiveness to the hormonal signal. The regulation of hormone receptor gene expression is therefore a central component of hormone action. Vertebrate steroid and thyroid hormones act by binding to nuclear receptors (NR) that function as ligand-activated transcription factors. Nuclear receptor genes are regulated by diverse and interacting intracellular signaling pathways. Nuclear receptor ligands can regulate the expression of the gene for the NR that mediates the hormone's action (autoregulation), thus influencing how a cell responds to the hormone. Autoregulation can be either positive or negative, the hormone increasing or decreasing, respectively, the expression of its own NR. Positive autoregulation (autoinduction) is often observed during postembryonic development, and during the ovarian cycle, where it enhances cellular sensitivity to the hormonal signal to drive the developmental process. By contrast, negative autoregulation (autorepression) may become important in the juvenile and adult for homeostatic negative feedback responses. In addition to autoregulation, a NR can influence the expression other types of NRs (cross-regulation), thus modifying how a cell responds to a different hormone. Cross-regulation by NRs is an important means to temporally coordinate cell responses to a subsequent (different) hormonal signal, or to allow for crosstalk between hormone signaling pathways.
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Affiliation(s)
- Pia Bagamasbad
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109, U.S.A
| | - Robert J. Denver
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109, U.S.A
- Department of Ecology and Evolutionary Biology, The University of Michigan, Ann Arbor, MI 48109, U.S.A
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8
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The assessment of non-feminizing estrogens for use in neuroprotection. Brain Res 2010; 1379:61-70. [PMID: 21111714 DOI: 10.1016/j.brainres.2010.11.058] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 11/03/2010] [Accepted: 11/18/2010] [Indexed: 11/22/2022]
Abstract
Menopause is associated with a precipitous decline in circulating estrogens and a resulting loss of the neuroprotective actions of this steroid hormone. In view of the results of the Women's Health Initiative and the preceding knowledge that orally administered estrogens has a variety of adverse side effects, likely through actions on peripheral estrogen receptor alpha (ERα), we initiated a program of research to synthesis and assess a group of non-feminizing estrogens that lack ability to interact with ERs but retain much of the neuroprotective action of feminizing estrogens. This program of research is aimed at the identification of compounds which do not stimulate ERs but are potentially neuroprotective in vitro and in animal models of neuronal cell death. We discovered that the most effective non-feminizing estrogens were those with large bulky groups in the 2 and/or 4 carbon of the phenolic A ring of the steroid. These compounds were 8- to 114-fold more potent than 17 β-estradiol (βE2), but lacked ER binding capacity in vitro and feminizing effects in vivo. The success of this program of research suggests that strategies to optimize non-feminizing estrogens for use in postmenopausal women can be successful.
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9
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Davis LK, Katsu Y, Iguchi T, Lerner DT, Hirano T, Grau EG. Transcriptional activity and biological effects of mammalian estrogen receptor ligands on three hepatic estrogen receptors in Mozambique tilapia. J Steroid Biochem Mol Biol 2010; 122:272-8. [PMID: 20553864 DOI: 10.1016/j.jsbmb.2010.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/19/2010] [Accepted: 05/20/2010] [Indexed: 12/21/2022]
Abstract
Like other fish species, Mozambique tilapia has three forms of estrogen receptor, ERα, ERβ1, and ERβ2. A primary function of 17β-estradiol (E(2)) in oviparous species is the hepatic induction of the yolk precursor protein, vitellogenin (Vg). To characterize the roles of ERs in Vg production, transactivation assays and an in vivo study were carried out utilizing agonists for mammalian ERα and ERβ, and an antagonist for mammalian ERα, propyl-pyrazole-triol (PPT), diarylpropionitrile (DPN), and methyl-piperidino-pyrazole (MPP), respectively. ERα was more sensitive and responsive to PPT than ERβ1 or ERβ2 in transactivation assays. All ER isoforms indicated equivalent responsiveness to DPN compared with E(2), although sensitivity to DPN was lower. MPP exhibited antagonistic action on transactivation of all ER isoforms and reduced the E(2) effect on Vg and ERα 48h post-injection. DPN increased ERα and Vg expression and plasma Vg post-injection, whereas PPT was without effect; DPN seems to stimulate Vg production through activation of ERα. The ligand binding domain of all tilapia ER forms shares only 60-65% amino acid identity with human ERα and ERβ. This, together with our results, clearly indicates that agonistic or antagonistic characteristics of PPT, DPN and MPP cannot be extrapolated from mammalian to piscine ERs.
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Affiliation(s)
- L K Davis
- Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1346, Kaneohe, HI 96744, USA
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10
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Ing NH. Estradiol up-regulates expression of the A + U-rich binding factor 1 (AUF1) gene in the sheep uterus. J Steroid Biochem Mol Biol 2010; 122:172-9. [PMID: 20621185 DOI: 10.1016/j.jsbmb.2010.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 06/21/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
Abstract
The A+U-rich binding factor 1 (AUF1 or HNRPD) gene produces predominant RNA binding proteins. The AUF1 transcript is alternatively spliced to produce four protein isoforms that stabilize or destabilize hundreds of mRNAs. Previously, we discovered that estradiol (E2) treatment of ovariectomized sheep increased concentrations of AUF1p45 protein which stabilized estrogen receptor alpha (ER) mRNA in the uterus. This study examined E2 regulation of AUF1 mRNAs in the sheep uterus. Northern analysis determined that E2 treatment increased concentrations of total AUF1 mRNAs twofold in endometrial and myometrial tissue compartments. In situ hybridization indicated that the increase was most intense in the glandular epithelium of endometrium. In a well characterized in vitro RNA stability assay, AUF1 3'UTR sequences were much more stable in uterine extracts from E2-treated ewes compared to extracts from control ewes. AUF1 mRNAs with alternative splicing of exons 2 and 7 (in the coding sequence) and exon 9 (in the 3'UTR) were identified. The only effect of E2 treatment on alternative splicing was that it reduced the percentage of AUF1 mRNAs containing exon 9-derived sequences. These data indicate that E2 up-regulates AUF1 and ER genes coordinately by a post-transcriptional mechanism.
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Affiliation(s)
- Nancy H Ing
- Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843-2471, United States
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11
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Baranda-Avila N, Cardoso-Rangel ME, Cerbón M, Camacho-Arroyo I, Mendoza-Rodríguez CA, Villaseñor-Gaona H, Anzaldúa-Arce SR. Differential expression of estrogen receptor alpha gene in the ampullae and isthmus regions of the rabbit oviduct during early pregnancy. Anim Reprod Sci 2010; 121:286-93. [DOI: 10.1016/j.anireprosci.2010.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/11/2010] [Accepted: 07/05/2010] [Indexed: 10/19/2022]
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12
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Shorten P, Peterson A, O’Connell A, Juengel J, McNatty K, Soboleva T. A mathematical model of pregnancy recognition in mammals. J Theor Biol 2010; 266:62-9. [DOI: 10.1016/j.jtbi.2010.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 05/31/2010] [Accepted: 06/02/2010] [Indexed: 01/28/2023]
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13
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Messenger RNA levels of estrogen receptors α and β and progesterone receptors in the cyclic and inseminated/early pregnant sow uterus. Anim Reprod Sci 2009; 112:215-28. [DOI: 10.1016/j.anireprosci.2008.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 04/10/2008] [Accepted: 04/23/2008] [Indexed: 11/22/2022]
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14
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Wiik A, Hellsten Y, Berthelson P, Lundholm L, Fischer H, Jansson E. Activation of estrogen response elements is mediated both via estrogen and muscle contractions in rat skeletal muscle myotubes. Am J Physiol Cell Physiol 2008; 296:C215-20. [PMID: 19020053 DOI: 10.1152/ajpcell.00148.2008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aim of the present study was to investigate the activation of estrogen response elements (EREs) by estrogen and muscle contractions in rat myotubes in culture and to assess whether the activation is dependent on the estrogen receptors (ERs). In addition, the effect of estrogen and contraction on the mRNA levels of ERalpha and ERbeta was studied to determine the functional consequence of the transactivation. Myoblasts were isolated from rat skeletal muscle and transfected with a vector consisting of sequences of EREs coupled to the gene for luciferase. The transfected myoblasts were then differentiated into myotubes and subjected to either estrogen or electrical stimulation. Activation of the ERE sequence was determined by measurement of luciferase activity. The results show that both ERalpha and ERbeta are expressed in myotubes from rats. Both estrogen stimulation and muscle contraction increased (P < 0.05) transactivation of the ERE sequence and enhanced ERbeta mRNA, whereas ERalpha was unaffected by estrogen and attenuated (P < 0.05) by muscle contraction. Use of ER antagonists showed that, whereas the estrogen-induced transactivation is mediated via ERs, the effect of muscle contraction is ER independent. The muscle contraction-induced transactivation of ERE and increase in ERbeta mRNA were instead found to be MAP kinase (MAPK) dependent. This study demonstrates for the first time that muscle contractions have a similar functional effect as estrogen in skeletal muscle myotubes, causing ERE activation and an enhancement in ERbeta mRNA. However, in contrast to estrogen, the effect is independent of ERs and dependent on MAPK, suggesting activation via the estrogen related receptor (ERR).
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Affiliation(s)
- A Wiik
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institute, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
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15
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Ing NH, Massuto DA, Jaeger LA. Estradiol up-regulates AUF1p45 binding to stabilizing regions within the 3'-untranslated region of estrogen receptor alpha mRNA. J Biol Chem 2007; 283:1764-1772. [PMID: 18029355 DOI: 10.1074/jbc.m704745200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Estradiol up-regulates expression of the estrogen receptor alpha gene in the uterus by stabilizing estrogen receptor alpha mRNA. Previously, we defined two discrete minimal estradiol-modulated stability sequences (MEMSS) within the extensive 3'-untranslated region of estrogen receptor alpha mRNA with an in vitro stability assay using cytosolic extracts from sheep uterus. We report here that excess MEMSS RNA inhibited the enhanced stability of estrogen receptor alpha mRNA in extracts from estradiol-treated ewes compared with those from control ewes. Several estradiol-induced MEMSS-binding proteins were characterized by UV cross-linking in uterine extracts from ewes in a time course study (0, 8, 16, and 24 h after estradiol injection). The pattern of binding proteins changed at 16 h post-injection, concurrent with enhanced estrogen receptor alpha mRNA stability and the highest rate of accumulation of estrogen receptor alpha mRNA. The predominant MEMSS-binding protein induced by estradiol treatment was identified as AUF1 (A + U-rich RNA-binding factor 1) protein isoform p45 (a product of the heterogeneous nuclear ribonucleoprotein D gene). Immunoblot analysis indicated that only two of four AUF1 protein isoforms were present in the uterine cytosolic extracts and that estradiol treatment strongly increased the ratio of AUF1 isoforms p45 to p37. Nonphosphorylated recombinant AUF1p45 protected estrogen receptor alpha mRNA in vitro in a dose-dependent manner. These studies describe estrogenic induction of AUF1p45 binding to the estrogen receptor alpha mRNA as a molecular mechanism for post-transcriptional up-regulation of gene expression.
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Affiliation(s)
- Nancy H Ing
- Department of Animal Science, Texas A & M University, College Station, Texas 77843; Veterinary Integrative Biosciences, Texas A & M University, College Station, Texas 77843.
| | - Dana A Massuto
- Veterinary Integrative Biosciences, Texas A & M University, College Station, Texas 77843
| | - Laurie A Jaeger
- Veterinary Integrative Biosciences, Texas A & M University, College Station, Texas 77843
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16
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García-Palencia P, Sánchez MA, Nieto A, Vilar MP, González M, Veiga-Lopez A, González-Bulnes A, Flores JM. Sex steroid receptor expression in the oviduct and uterus of sheep with estrus synchronized with progestagen or prostaglandin analogues. Anim Reprod Sci 2006; 97:25-35. [PMID: 16466867 DOI: 10.1016/j.anireprosci.2006.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 12/26/2005] [Accepted: 01/04/2006] [Indexed: 11/15/2022]
Abstract
The objective of this study was to investigate differences in the expression of estrogen receptor-alpha (ERalpha), progesterone receptor (PR) and the proliferative indexes (Ki-67), in the uterus and oviduct of sheep with estrus synchronized either by prostaglandin analogues (Group PA, n=27) or by treatment with progestagens (Group P, n=29) on days 4 and 7 (day 0=estrus), when the embryos were collected. Immunohistochemical methods were used to quantify ERalpha, PR and Ki-67 in six superficial and deep compartments in the uterus and oviduct. The expression of ERalpha was significantly (P<0.01) lower in progestagen treated ewes than in prostaglandin analogues treated group in the luminal epithelium, superficial glands and superficial stroma in the uterus on day 4. The expression of PR was significantly lower in progesterone treated ewes than in the PA Group in the superficial gland (P<0.05) in both days studied. The lowest expression of PR was observed in the luminal caruncular epithelium and superficial glands in both treatments, obtaining the lowest levels on day 4 (P<0.05). There were significant differences between days 4 and 7 in the Ki-67 immunostaining in the luminal epithelium (P<0.01) and superficial glands (P<0.05). A higher cell proliferation was observed in the uterine epithelium (P<0.05) on day 4 in the animals treated with progestagens. Results indicate that sheep with synchronization of estrus with progestagens showed a reduction of ERalpha and PR protein expression in most of oviductal and uterine cells.
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Affiliation(s)
- P García-Palencia
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, UCM, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
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17
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Perez E, Liu R, Yang SH, Cai ZY, Covey DF, Simpkins JW. Neuroprotective effects of an estratriene analog are estrogen receptor independent in vitro and in vivo. Brain Res 2005; 1038:216-22. [PMID: 15757637 DOI: 10.1016/j.brainres.2005.01.026] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 01/07/2005] [Accepted: 01/10/2005] [Indexed: 11/15/2022]
Abstract
Estrogens are potent neuroprotectants both in vitro and in vivo. In the present study, we compared the potency and efficacy of a non-feminizing estrogen, 2-(1-adamantyl)-4-methylestrone (ZYC-26), with its parent estrogen, estrone, and an expected non-neuroprotective 3-O-methyl analog of (17beta)-2-(1-adamantyl)estradiol (ZYC-23). These estratriene derivatives were tested for their ability to protect in an in vitro lipid peroxidation model, to neuroprotect against oxidative stress in cell culture models, to bind the estrogen receptors (ERalpha and ERbeta), to elicit uterotrophic effects, and to affect brain damage from transient middle cerebral artery occlusion. We observed that in contrast to estrone, neither ZYC-26 nor ZYC-23 bound to either estrogen receptors (ER) and both failed to elicit a uterotrophic response. In vitro, the active estrogen analogue ZYC-26 was more potent that estrogen in its ability to inhibit lipid peroxidation and to protect HT-22 cells from either glutamate or iodoacetic acid (IAA) toxicity. Further, ZYC-26 was as active in preventing brain damage from transient middle cerebral artery occlusion (MCAO) as was estrone. Collectively, these studies suggest that the antioxidant activity, rather than ER binding of non-feminizing estrogens such as ZYC-26, mediates their potent neuroprotective activity. Further, in view of the now known toxicities of chronic feminizing estrogen use in older women, non-feminizing estrogens may be a useful alternative for estrogen-induced brain protection.
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Affiliation(s)
- Evelyn Perez
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
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18
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Ing NH. Steroid hormones regulate gene expression posttranscriptionally by altering the stabilities of messenger RNAs. Biol Reprod 2005; 72:1290-6. [PMID: 15728791 DOI: 10.1095/biolreprod.105.040014] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hormones exert powerful effects on reproductive physiology by regulating gene expression. Recent discoveries in hormone action emphasize that regulation of gene expression is not restricted to their alterations of the rate of gene transcription. On the contrary, hormonal effects on the stability of a specific mRNA can profoundly alter its steady-state concentration. The mRNAs encoding hormone receptors are commonly regulated by their own hormones to create autoregulatory feedback loops. Negative and positive autoregulatory feedback loops serve to limit or augment hormonal responses, respectively. After introducing the topics of mRNA degradation and regulated stability, this review focuses on steroid hormone effects on mRNA stabilities. Autoregulation of the mRNAs encoding estrogen, progesterone, androgen, and glucocorticoid receptors by the steroid hormones in reproductive tissues is discussed. In addition, steroid hormone effects on the stabilities of many other mRNAs that are important to reproductive biology are reviewed. These include mRNAs that encode gonadotropin hormones, integrins, growth factors, and inflammatory response proteins. Through these posttranscriptional effects, steroid hormones impact the expression of a large population of genes. Studies of the molecular mechanisms of hormonally regulated mRNA stabilities continue to identify critical mRNA sequence elements and their interactions with proteins. Increased understanding of how hormones affect mRNA stability may yield novel approaches to the therapeutic control of hormone effects, including those essential to reproductive physiology in animals.
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Affiliation(s)
- Nancy H Ing
- Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471, USA.
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19
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Balaguer SA, Pershing RA, Rodriguez-Sallaberry C, Thatcher WW, Badinga L. Effects of Bovine Somatotropin on Uterine Genes Related to the Prostaglandin Cascade in Lactating Dairy Cows. J Dairy Sci 2005; 88:543-52. [PMID: 15653519 DOI: 10.3168/jds.s0022-0302(05)72716-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Multiparous Holstein cows, averaging 80 d in milk, were used to examine the effect of exogenous bovine somatotropin (bST) on uterine expression of estrogen receptor alpha (ERalpha), prostaglandin endoperoxide synthase-2 (PGHS-2), and peroxisome proliferator-activated receptor delta (PPARdelta). About 12 h before expected ovulation in a synchronization protocol, cows were assigned to receive bST (500 mg, n = 11) or serve as untreated controls (n = 10). Cows that ovulated (n = 9 bST, 8 control) were divided within treatment to be killed on d 3 or 7 postovulation. Samples of intercaruncular endometrial tissue from uterine horns ipsilateral to the corpus luteum were collected and stored at -80 degrees C for subsequent mRNA analyses. Endometrial concentrations of ERalpha and PGHS-2 mRNA transcripts were greater on d 7 than on d 3 of the estrous cycle, but did not differ between treatments. Compared with untreated cows, short-term bST treatment decreased PGHS-2 protein expression at d 7 of the estrous cycle. Concentration of PPARdelta mRNA transcript in the uterus decreased between d 3 and 7 of the estrous cycle and was negatively correlated with ERalpha and PGHS-2 mRNA concentrations. Short-term administration of bST to lactating dairy cows had minimal effects on uterine genes encoding ERalpha, PGHS-2, and PPARdelta at d 3 and 7 of the estrous cycle but there may be an inverse relationship between PPARdelta and uterine expression of ERalpha and PGHS-2 genes.
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Affiliation(s)
- S A Balaguer
- Department of Animal Sciences, University of Florida, Gainesville 32611, USA
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20
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Kretz O, Fester L, Wehrenberg U, Zhou L, Brauckmann S, Zhao S, Prange-Kiel J, Naumann T, Jarry H, Frotscher M, Rune GM. Hippocampal synapses depend on hippocampal estrogen synthesis. J Neurosci 2004; 24:5913-21. [PMID: 15229239 PMCID: PMC6729232 DOI: 10.1523/jneurosci.5186-03.2004] [Citation(s) in RCA: 333] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Estrogens have been described to induce synaptogenesis in principal neurons of the hippocampus and have been shown to be synthesized and released by exactly these neurons. Here, we have focused on the significance of local estrogen synthesis on spine synapse formation and the synthesis of synaptic proteins. To this end, we reduced hippocampal estrogen synthesis in vitro with letrozole, a reversible nonsteroidal aromatase inhibitor. In hippocampal slice cultures, letrozole treatment resulted in a dose-dependent decrease of 17beta-estradiol as quantified by RIA. This was accompanied by a significant decrease in the density of spine synapses and in the number of presynaptic boutons. Quantitative immunohistochemistry revealed a downregulation of spinophilin, a marker of dendritic spines, and synaptophysin, a protein of presynaptic vesicles, in response to letrozole. Surprisingly, no increase in the density of spines, boutons, and synapses and in spinophilin expression was seen after application of estradiol to the medium of cultures that had not been treated with letrozole. However, synaptophysin expression was upregulated under these conditions. Our results point to an essential role of endogenous hippocampal estrogen synthesis in the maintenance of hippocampal spine synapses.
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Affiliation(s)
- Oliver Kretz
- Institute of Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
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21
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Gunin AG, Emelianov VU, Mironkin IU, Morozov MP, Tolmachev AS. Lithium treatment enhances estradiol-induced proliferation and hyperplasia formation in the uterus of mice. Eur J Obstet Gynecol Reprod Biol 2004; 114:83-91. [PMID: 15099877 DOI: 10.1016/j.ejogrb.2003.09.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2003] [Revised: 06/18/2003] [Accepted: 09/05/2003] [Indexed: 11/24/2022]
Abstract
OBJECTIVES It is suggested that the Wnt/beta-catenin pathway plays a role in the regulation of estrogen action in the uterus. However, this suggestion has not been proved. Lithium can mimic increased activity of the Wnt/beta-catenin pathway by blocking the activity of glycogen synthase kinase-3beta. There are no data on the effects of lithium on estrogen-dependent processes in the uterus. This work was therefore aimed to examine the action of lithium on proliferative and morphogenetic reactions in the uterus under short- and long-term estrogen treatments. STUDY DESIGN Ovariectomized mice received estradiol dipropionate (2 microg per 100g; s.c.) once a week or vehicle and drank tap water with 0.05% lithium chloride or plain tap water for 2 or 30 days. RESULTS In animals treated with estradiol and lithium for a month, the incidence of atypical endometrial hyperplasia was significantly higher. In animals treated with estradiol and lithium for 2 days or for a month, uterine mass, the number of mitotic cells and BrdU-labelled cells in luminal epithelium, glandular epithelium, stromal and myometrial cells was markedly greater, whereas the levels of estrogen receptors-alpha, beta-catenin and glycogen synthase kinase-3beta were markedly lower in all uterine compartments, than in those in mice received estradiol with no lithium to drink. CONCLUSIONS Lithium treatment results in an increase in estradiol-induced proliferative and morphogenetic changes in the uterus. This action of lithium is associated with decreased expression of estrogen receptors-alpha, beta-catenin and glycogen synthase kinase-3beta in the uterus.
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Affiliation(s)
- Andrei G Gunin
- Department of Histology, Medical School Chuvash State University, 428034 Cheboksary, Russia.
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22
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Abstract
One of the difficulties associated with commercial layer production is the development of osteoporosis in hens late in the production cycle. In light of this fact and because of hens' unique requirements for Ca, many studies have focused on the regulation of Ca and the role of estrogen in this process. The time course of estrogen synthesis over the productive life of hens has been well documented; increased circulating estrogen accompanies the onset of sexual maturity while decreases signal a decline in egg production prior to a molt. Numbers of estrogen receptors decrease with age in numerous tissues. The parallel changes in calcium-regulating proteins, primarily Calbindin D28K, and in the ability of duodenal cells to transport Ca, are thought to occur as a result of the changes in estrogen, and are also reversible by the molt process. In addition to the traditional model of estrogen action, evidence now exists for a possible nongenomic action of estrogen via membrane-bound receptors, demonstrated by extremely rapid surges of ionized Ca in chicken granulosa cells in response to 17beta-estradiol. Estrogen receptors have also been discovered in duodenal tissue, and tamoxifen, which binds to the estrogen receptor, has been shown to cause a rapid increase in Ca transport in the duodenum. In addition, recent evidence also suggests that mineralization of bone per se may not explain entirely the etiology of osteoporosis in the hen but that changes in the collagen matrix may contribute through decreases in bone elasticity. Taken together, these studies suggest that changes in estrogen synthesis and estrogen receptor populations may underlie the age-related changes in avian bone. As with postmenopausal women, dietary Ca and vitamin D are of limited benefit as remedies for osteoporosis in the hen.
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Affiliation(s)
- M M Beck
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA.
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23
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Cárdenas H, Pope WF. Attenuation of Estrogenic Effects by Dihydrotestosterone in the Pig Uterus Is Associated with Downregulation of the Estrogen Receptors1. Biol Reprod 2004; 70:297-302. [PMID: 14522825 DOI: 10.1095/biolreprod.103.022384] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Androgens are known to attenuate some effects of estradiol-17beta (E) in the uterus. The objectives of the present experiment were to determine effects of 5alpha-dihydrotestosterone (DHT) on estrogenic actions in the pig uterus and its associations with changes in expression of the estrogen receptor (ER) alpha and ERbeta. Postpubertal gilts (120-130 kg of body weight; n = 16) were ovariectomized, and 3-4 weeks later received once-a-day injections (i.m.) of one of the following treatments during four consecutive days: 1) vehicle (corn oil), 2) E (250 microg), 3) E (250 microg) plus 1 mg DHT, or 4) E (250 microg) plus 10 mg DHT. Uterine tissues were collected 24 h after the last treatment. Gilts receiving E or E plus 1 mg DHT had greater uterine wet weight, uterine horn diameter, luminal epithelium thickness, and endometrial gland diameter compared with gilts treated with vehicle or E plus 10 mg DHT. Gilts receiving E or E plus 1 mg DHT were not different in these characteristics. Relative amounts of mRNAs in the endometrium for the cell proliferation marker histone H2a and the E-inducible protein complement component C3 increased in gilts treated with E compared with gilts treated with vehicle. E-induced increases in histone H2a and C3 mRNAs were not altered by cotreatment with E plus 1 mg DHT but were inhibited by E plus 10 mg DHT. Androgen receptor (AR) mRNA in the endometrium increased by treatment with E. Cotreatment of gilts with E and DHT did not alter the E-induced AR mRNA increase. Gilts treated with E plus 10 mg DHT had lesser amounts of immunoreactive ERalpha in cell nuclei of the myometrium and endometrial stroma and a tendency for a decrease in luminal epithelium compared with gilts treated with E. Amounts of immunoreactive ERalpha in glandular epithelium were not influenced by the treatments. Relative amounts of ERalpha and ERbeta mRNAs decreased in the endometrium of gilts treated with E plus 10 mg DHT compared with gilts treated with E. Downregulation of the ERs, particularly ERalpha in the myometrium and endometrial stroma, might be a relevant mechanism in the antagonism of estrogenic effects by DHT in the pig uterus.
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Affiliation(s)
- Horacio Cárdenas
- Department of Animal Sciences, The Ohio State University, Columbus, Ohio 43210, USA.
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24
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Theodosiadou E, Goulas P, Kouskoura T, Smokovitis A. Oestrogen and progesterone concentrations in plasma and oviductal tissue of ewes exhibiting a natural or induced oestrus. Anim Reprod Sci 2004; 80:59-67. [PMID: 15036515 DOI: 10.1016/s0378-4320(02)00223-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2001] [Revised: 08/28/2002] [Accepted: 09/29/2002] [Indexed: 11/23/2022]
Abstract
Synchronisation of oestrus in Karagouniki ewes by administration of the standard dose of progesterone results in lower fertility than observed when these ewes ovulate naturally. This suggests that the optimum dose of progesterone may be breed dependent. The exogenous progesterone may perturb the concentrations of oestradiol-17beta and progesterone in blood plasma and the oviductal wall. This possibility was investigated using Karagouniki ewes allocated at random to three treatments (n=4 per treatment). Ewes were allowed to exhibit natural oestrus (N) or oestrus was synchronised by administration of 250 mg (LP) or 375 mg (HP) progesterone (subcutaneous implants) followed by PMSG at 8 mg/kg live weight i.m. 14 days later. Oestrus was observed using teaser rams. Blood samples were collected for plasma oestradiol-17beta and progesterone assay from the onset to the end of oestrus at 2 h intervals. The uterus of each ewe was recovered at the end of oestrus and samples of the oviductal wall were taken from both oviducts and prepared, separately, for progesterone and oestradiol-17beta assay. Statistical analysis was performed using univariate analysis of variance. Plasma oestradiol-17beta concentrations from the onset to the end of oestrus were highest for N ewes and lowest for HP ewes with the values for LP ewes occupying an intermediate position. The differences were significant (P<0.05) between HP and the other two treatments from 4 to 12 h after the onset of oestrus and then between all treatments until the end of oestrus. Plasma progesterone levels were similar and fairly constant from the onset to the end of oestrus for N and LP. The plasma progesterone levels for HP were significantly (P<0.05) higher than for the other two treatments throughout oestrus. In oviductal wall samples, the oestradiol-17beta concentration was significantly (P<0.05) higher for N ewes than for synchronised ewes and the levels were similar for LP and HP ewes. The concentration of oestradiol-17beta differed (P<0.05) between right and left oviducts for N ewes but not for ewes of either of the synchronised oestrus treatments. Progesterone concentrations in oviductal wall samples were highest (P<0.05) for HP ewes and the values for N and LP ewes were similar. The concentration of progesterone did not differ between right and left oviductal wall samples within treatments. It was concluded that the higher dose of exogenous progesterone perturbed the levels of oestradiol-17beta and progesterone in blood plasma and the oviductal wall, and this could explain the lower levels of fertility (relative to naturally occurring oestrus) observed when this protocol is used for Karagouniki ewes in practice.
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Affiliation(s)
- E Theodosiadou
- Department of Physiology, Faculty of Veterinary Medicine, Aristotle University, Thessaloniki 541 24, Greece
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25
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Meikle A, Tasende C, Sosa C, Garófalo EG. The role of sex steroid receptors in sheep female reproductive physiology. Reprod Fertil Dev 2004. [DOI: 10.1071/rd04036] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cell responsiveness to steroid hormones is related to the number and affinity of its receptors, thus factors affecting steroid expression will influence tissue sensitivity and functionality. The present review discusses the role of oestrogen and progesterone receptors in sheep female reproductive physiology. The mechanism of steroid hormone action in the target cell is introduced first; the tissue distribution, physiological functions and regulation of oestrogen receptor subtypes and progesterone receptor isoforms in ruminants are reported. The role of steroid receptors in target tissues (with emphasis on the uterus and pituitary gland) during different physiological events is addressed in an attempt to clarify oestrogen and progesterone actions in different developmental and reproductive stages: prepubertal period, oestrous cycle, pregnancy, post-partum period and seasonal anoestrus. The present review shows how the distinct reproductive stages are accompanied by dramatic changes in uterine receptor expression. The role of oestrogen and progesterone receptors in the molecular mechanism responsible for premature luteolysis that results in subnormal luteal function is discussed. Finally, the effect of nutrition on sex steroid receptor expression and the involvement on reproductive performance is reported.
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26
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Morrison AG, Callanan JJ, Evans NP, Aldridge TC, Sweeney T. Effects of endocrine disrupting compounds on the pathology and oestrogen receptor alpha and beta distribution in the uterus and cervix of ewe lambs. Domest Anim Endocrinol 2003; 25:329-43. [PMID: 14652134 DOI: 10.1016/j.domaniend.2003.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A number of chemicals have been classed as endocrine disrupting compounds due to their ability to mimic the actions of endogenous hormones in vivo and in vitro. The objective of this experiment was to determine the pathological changes and oestrogen receptor (ER) distribution in the cervix and uterus of prepubertal ovariectomised ewe lambs following exposure to a range of compounds with a predominantly oestrogenic effect. Lambs were exposed to diethylstilbestrol (0.175 mg/kg biweekly), bisphenol-A (3.5mg/kg biweekly) or octylphenol (3.5mg/kg biweekly) for 6 weeks. Following sacrifice, uterine and cervical tissue pathology was assessed. The endometrial and myometrial areas were quantified and the distribution of ERalpha and ERbeta assessed by immunohistochemistry. No differences were observed between control and octylphenol-exposed lambs in uterine gross pathology and histopathology. Uteri from bisphenol-A- and diethylstilbestrol-exposed lambs were heavier than both control and octylphenol-exposed lambs. In the bisphenol-A-exposed lambs, endometrial oedema accounted for a significant increase in the endometrial cross-sectional area over the other groups. Uteri from animals exposed to diethylstilbestrol showed variable pathology including oedema and cellular proliferation. Keratinisation of the cervical epithelium was observed in both bisphenol-A- and diethylstilbestrol-exposed lambs. Exposure to diethylstilbestrol and bisphenol-A was associated with a diffuse intracellular distribution of ERalpha and ERbeta in the uterine endometrium. This was in addition to the strong cytoplasmic staining of uterine epithelial cells and nuclear staining of specific sub-epithelial cells observed in all groups. We conclude that a 6-week exposure of lambs to bisphenol-A and diethylstilbestrol altered the uterocervical environment and has the potential to disrupt subsequent reproductive function. Pathological changes could not be detected in the uterus or cervix of lambs exposed to octylphenol.
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Affiliation(s)
- A G Morrison
- Department of Animal Husbandry and Production, Faculty of Veterinary Medicine, Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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27
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Murata T, Narita K, Honda K, Matsukawa S, Higuchi T. Differential regulation of estrogen receptor alpha and beta mRNAs in the rat uterus during pregnancy and labor: possible involvement of estrogen receptors in oxytocin receptor regulation. Endocr J 2003; 50:579-87. [PMID: 14614214 DOI: 10.1507/endocrj.50.579] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Oxytocin receptor (OTR) mRNA levels in the uterus dramatically increase in the near term human and rat. Estrogen is believed to be a potent stimulator of OTR mRNA expression. However, estrogen does not stimulate rat OTR mRNA expression on day 18 of pregnancy or in progesterone-treated rats. Thus, the regulation of uterine responsiveness to estrogen in the near term rat appears to be an important mediator of estrogen action. To determine the effect of altering uterine responsiveness to estrogen on OTR induction, uterine ERalpha and ER beta mRNA levels were examined by competitive RT-PCR in pregnant and parturient rats, progesterone-treated ovariectomized (OVX) virgin rats and OVX pregnant rats. In pregnant and parturient rats, OTR mRNA levels were highest at 2200-2230 h on day 21 of pregnancy (P21pm) and during labor when compared with other groups. ERalpha mRNA levels significantly increased during labor compared with days 15-21 of pregnancy. Compared with control animals, ERalpha mRNA levels decreased significantly in OVX virgin rats implanted with tubes containing progesterone for one week; 24 h following the removal of the progesterone tubes, ERalpha mRNA levels were found to be similar to control levels. Estrogen treatment following OVX on day 18 of pregnancy caused increased OTR mRNA levels, whereas ovariectomy alone increased ERbeta mRNA but not ERalpha mRNA. Results from the present study suggest that ERalpha and ERbeta mRNA expressions are differentially regulated in the rat uterus. Moreover, during spontaneous labor our findings appear to suggest that ERalpha plays a more prominent role than ERbeta in mediating estrogen action in the induction of uterine OTR mRNA before labor.
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Affiliation(s)
- Takuya Murata
- Department of Physiology, Fukui Medical University, Shimoaizuki, Matsuoka, Japan
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28
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Bennett HL, Gustafsson JA, Keast JR. Estrogen receptor expression in lumbosacral dorsal root ganglion cells innervating the female rat urinary bladder. Auton Neurosci 2003; 105:90-100. [PMID: 12798205 DOI: 10.1016/s1566-0702(03)00044-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have investigated whether bladder afferent neurons are likely to be targets for circulating estrogens by mapping estrogen receptor (ER) distribution in lumbosacral dorsal root ganglia (DRG) of adult female rats. Sensory neurons innervating either the detrusor or trigone regions were identified by application of fluorescent retrograde tracer dyes to the bladder wall. Labelled neurons were classified by their immunoreactivity for either type of ER (ERalpha or ERbeta) and further compared with subpopulations of neurons containing substance P, calcitonin gene-related peptide and vanilloid receptor (a marker of polymodal nociceptors). Both ER types were expressed in numerous sensory neurons of either upper lumbar (L1/L2) or lower lumbar/sacral (L6/S1) ganglia and there was almost complete coexpression of ERalpha and ERbeta. ER-positive neurons were mainly small-medium size (18-25-microm diameter), indicating that they may be nociceptors and/or supply visceral targets. Most bladder-projecting neurons expressed ERs and the majority of these also expressed neuropeptides or vanilloid receptor. Afferent neurons supplying detrusor and trigone regions had similar immunohistochemical features. About a third of the bladder-projecting neurons expressed both ER and vanilloid receptor, suggesting a mechanism by which estrogens could influence bladder pain. The prevalence of different chemical classes of ER-positive bladder-projecting neurons was reflected throughout the entire population of neurons in dorsal root ganglia of these spinal levels, suggesting that neurons supplying other pelvic visceral targets may have similar chemical profiles. These results suggest that many functional classes of sensory neurons innervating the lower urinary tract are likely to be targets for circulating estrogens, including many nociceptor neurons. The coexistence of ERalpha and ERbeta suggests a broad range of potential mechanisms by which estrogens may exert their genomic effects in this system.
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Affiliation(s)
- Haley L Bennett
- Prince of Wales Medical Research Institute, University of New South Wales, NSW 2052, Sydney, Australia
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29
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Mitchell DC, Ing NH. Estradiol stabilizes estrogen receptor messenger ribonucleic acid in sheep endometrium via discrete sequence elements in its 3'-untranslated region. Mol Endocrinol 2003; 17:562-74. [PMID: 12554762 DOI: 10.1210/me.2002-0313] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The preovulatory surge of estrogen up-regulates estrogen receptor-alpha (ER) gene expression in the uterus during the estrous/menstrual cycles of female mammals. Previously, we demonstrated that the 5-fold increase in ER mRNA levels in endometrium of ovariectomized ewes treated with a physiological dose of estradiol (E2) is entirely due to an increase in ER mRNA stability. Our current work confirms that the E2 effect is specific to ER mRNA. The sequence of ER mRNA, cloned from sheep endometrium, shows a high degree of conservation with those of other species, even in the 5'- and the very long 3'-untranslated regions. In a cell-free assay, ER mRNA demonstrates greater stability with endometrial extracts from E2-treated ewes compared with those from untreated ovariectomized ewes. The E2-enhanced stability of ER mRNA was ablated by prior treatment of the extracts with proteinase K, 70 C heat, and oxidizing and alkylating reagents, indicating that a protein is responsible for stabilization of the message. The 3'-untranslated region of ER mRNA contains discrete sequences required for E2-enhanced stability, four of which were identified by extensive deletion mutant analyses. Transfer of two of the four minimal E2-modulated stability sequences conferred E2-enhanced stability to a heterologous RNA. These minimal E2-modulated stability sequences contain a common 10-base, uridine-rich sequence that is predicted to reside in a loop structure. Throughout our studies, estrogen stabilization of ER mRNA in sheep endometrium resembled that of vitellogenin mRNA in frog liver, indicating conservation of this ancient mechanism for enhancing gene expression in response to estrogen.
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Affiliation(s)
- Dianne C Mitchell
- Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471, USA
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30
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Farnell YZ, Ing NH. Endometrial effects of selective estrogen receptor modulators (SERMs) on estradiol-responsive gene expression are gene and cell-specific. J Steroid Biochem Mol Biol 2003; 84:513-26. [PMID: 12767276 DOI: 10.1016/s0960-0760(03)00076-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Three selective estrogen receptor modulator (SERM) drugs which included 4-OH-tamoxifen (Tam), EM-800 (EM) and GW 5638 (GW) were investigated to determine their ability to inhibit estradiol-responsive gene expression in sheep endometrium. The uteri of ovariectomized ewes (10 ewes per SERM group) were infused with 10(-7)M SERMs for 24h prior to hysterectomy. Five ewes from each group received 50 microg 17beta-estradiol (E2) and the remaining five ewes received vehicle 18 h prior to hysterectomy. Northern blot analyses and in situ hybridization demonstrated that E2 treatment increased estrogen receptor (ER), progesterone receptor (PR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and cyclophilin (CYC) mRNA levels in most endometrial cells examined. Tam and GW exhibited characteristics similar to E2 by increasing ER gene expression, but they antagonized the E2-induced increases in PR and CYC mRNA levels. EM acted as an E2-agonist of GAPDH gene expression, but antagonized the E2 up-regulation of ER, PR and CYC gene expression in most endometrial cells. Immunohistochemistry determined that EM decreased ER protein levels in the glandular epithelium, and the SERMs investigated antagonized increases in PR protein levels in endometrium. In conclusion, GW and EM exhibit fewer agonist effects than Tam on endometrial gene expression. EM demonstrated the greatest antagonism of E2-enhanced levels of ER, PR and CYC, likely due to the inhibition of ER gene expression at both mRNA and protein levels.
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Affiliation(s)
- Yuhua Z Farnell
- Department of Animal Science, Faculties of Genetics and Reproductive Biology, Texas A&M University, College Station, TX 77843-2471, USA
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31
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Farnell YZ, Ing NH. The effects of estradiol and selective estrogen receptor modulators on gene expression and messenger RNA stability in immortalized sheep endometrial stromal cells and human endometrial adenocarcinoma cells. J Steroid Biochem Mol Biol 2003; 84:453-61. [PMID: 12732290 DOI: 10.1016/s0960-0760(03)00066-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to identify an endometrial cell line that maintained the E2 up-regulation of estrogen receptor (ER) mRNA by enhanced message stability and to assess its dependence on ER protein. Estradiol (E2) effects on gene expression were measured in three cell lines: one immortalized from sheep endometrial stroma (ST) and two from human endometrial adenocarcinomas (Ishikawa and ECC-1). E2 up-regulated ER mRNA levels in ST and Ishikawa cells, but down-regulated ER mRNA levels in ECC-1 cells. E2 up-regulated progesterone receptor (PR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and transforming growth factor-alpha (TGF-alpha) in both Ishikawa and ECC-1 cells. The selective estrogen receptor modulator ICI 182,780 antagonized the E2-induced up-regulation of ER and/or PR mRNA levels in all three cells, while another, GW 5638, antagonized the up-regulation of PR mRNA in Ishikawa and ECC-1 cells. In mechanistic studies, E2 had no effect on ER mRNA stability in ST cells and it destabilized ER mRNA in ECC-1 cells. Thus, Ishikawa cells appear to be the most physiologically relevant cell line in which to study the up-regulation of ER mRNA levels by enhanced mRNA stability. Its antagonism by ICI 182,780 reveals that ER protein is involved in this E2 response.
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Affiliation(s)
- Yuhua Z Farnell
- Departments of Animal Science, Faculty of Genetics, Texas A&M University, College Station, TX 77843-2471, USA
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32
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Sukjumlong S, Kaeoket K, Dalin AM, Persson E. Immunohistochemical studies on oestrogen receptor alpha (ER alpha) and the proliferative marker Ki-67 in the sow uterus at different stages of the oestrous cycle. Reprod Domest Anim 2003; 38:5-12. [PMID: 12535323 DOI: 10.1046/j.1439-0531.2003.00383.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to better understand physiological changes during the different stages of the oestrous cycle, immunohistochemistry was used in the present study to investigate the distribution of oestrogen receptor alpha (ER alpha) as well as the proliferative marker Ki-67, in the sow uterus during the oestrous cycle. Uterine samples were collected from multiparous sows with normal reproductive performance at selected stages of the oestrous cycle: at late dioestrus (d 17), prooestrus (d 19), oestrous (d 1), early dioestrus (d 4) and dioestrus (d 11-12), respectively. The tissue samples were fixed in 10% formaldehyde, embedded in paraffin and subjected to immunohistochemistry using monoclonal antibodies against ER alpha (C-311) and Ki-67 (MM-1). In general, the immunostaining of both ER alpha and Ki-67 was confined to nuclei of the target cells. Variations were seen, not only at the different stages of the oestrous cycle, but also in the different tissue compartments of the uterus. In the epithelia, the strongest ER alpha staining and highest amount of positive Ki-67 cells were found at early dioestrus. In the myometrium, the highest levels of staining of both ER alpha and Ki-67 positive cells were found at pro-oestrus and oestrus. For the proliferative marker, Ki-67, no positive cells were found at dioestrus and late dioestrus in the epithelium and myometrium. In the connective tissue stroma (subepithelial layer), the highest number of ER alpha positive cells were found at oestrus, which was significantly different compared with other stages (p< or = 0.05), whereas the levels of Ki-67 positive cells were relatively low and did not differ between the stages examined. Significant correlations between the number of ER alpha positive cells in the stroma and Ki-67 positive cells in the epithelia were observed. This suggests indirect regulatory mechanisms on epithelial proliferation via ER alpha in the stroma. In conclusion, these findings in the sow uterus show that the presence of ER alpha as well as Ki-67 protein varies not only between different stages of the oestrous cycle but also between different tissue compartments of the uterus. These findings indicate various regulatory mechanisms and stress the importance of localising ER alpha and proliferating cells in different uterine tissues.
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Affiliation(s)
- S Sukjumlong
- Department of Anatomy and Histology, Centre for Reproductive Biology in Uppsala (CRU), Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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33
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Farnell YZ, Ing NH. Estradiol and a selective estrogen receptor modulator affect steroid hormone receptor messenger RNA levels and turnover in explant cultures of sheep endometrium. In Vitro Cell Dev Biol Anim 2002; 38:595-600. [PMID: 12762841 DOI: 10.1290/1543-706x(2002)38<595:eaaser>2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Estrogens upregulate estrogen receptor (ER) and progesterone receptor (PR) gene expression in endometrium immediately before ovulation to prepare it for nurturing embryos. Most in vitro model systems have lost the ability to upregulate expression of the ER gene in response to estradiol (E2) or the ability to express the ER gene at all. Here, we used explant cultures from control and E2-treated ewes and assessed expression of four genes (ER, PR, glyceraldehyde 3-phosphate dehydrogenase [GAPDH], and cyclophilin [CYC] genes) that are upregulated by E2 in vivo on Northern blots. In cultures from control and E2-treated ewes, ER and PR messenger ribonucleic acid (mRNA) levels dropped significantly during 24 h of culture in the absence of E2. Glyceraldehyde 3-phosphate dehydrogenase mRNA levels increased 300% in explants from control ewes to match the higher levels in the endometrium of the E2-treated ewe (in vivo and in explant culture). The only effect of E2 in the explant cultures was to prevent the decrease in PR mRNA. The new selective ER modulator, EM-800 (EM), decreased ER and PR mRNA levels in explants from control ewes but upregulated GAPDH and CYC mRNA levels. The EM treatment in vitro mimicked that of E2 by increasing the half-life of ER mRNA in endometrial explants. These data illustrate distinct, gene-specific effects of the explant culture process, E2, and EM on the expression of endometrial genes.
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Affiliation(s)
- Yuhua Z Farnell
- Department of Animal Science, Center for Animal Biotechnology and Genomics, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
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34
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Sabourin T, Morissette G, Bouthillier J, Levesque L, Marceau F. Expression of kinin B(1) receptor in fresh or cultured rabbit aortic smooth muscle: role of NF-kappa B. Am J Physiol Heart Circ Physiol 2002; 283:H227-37. [PMID: 12063295 DOI: 10.1152/ajpheart.00978.2001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kinin B(1) receptor (B(1)R) expression and the importance of the transcription factor nuclear factor (NF)-kappa B in this process were evaluated in models based on the rabbit aorta: freshly isolated tissue (postisolation induction) and cultured smooth muscle cells (SMCs). A 3-h incubation of freshly isolated tissues determined a sharp B(1)R mRNA increase (RT-PCR). Coincubation of tissues with a stimulus (interleukin-1 beta, fetal bovine serum, epidermal growth factor, or cycloheximide) further increased mRNA levels. Cultured SMCs possessed a basal population of surface B(1)Rs ([(3)H]Lys-des-Arg(9)-bradykinin binding) that was upregulated by treatments with the same set of stimuli (binding, mRNA, nuclear runon). Pharmacological inhibitors of NF-kappa B (MG-132, BAY 11-7082, dexamethasone) or actinomycin D reduced the postisolation induction of B(1)Rs in fresh aortic tissue (contractility or mRNA) and the cytokine effect on cells (mRNA, binding). NF-kappa B may be a common mediator of various stimuli that increase B(1)R gene transcription in the rabbit aorta, including tissue isolation, but cycloheximide also stabilizes B(1)R mRNA. The SMC models faithfully mimic the in vivo situation with regard to B(1)R regulation.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Blood Proteins/pharmacology
- Cells, Cultured
- Dexamethasone/pharmacology
- Dose-Response Relationship, Drug
- Epidermal Growth Factor/pharmacology
- Interleukin-1/pharmacology
- Leupeptins/pharmacology
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NF-kappa B/metabolism
- Nitriles
- Nucleic Acid Synthesis Inhibitors/pharmacology
- Organic Chemicals
- Protein Synthesis Inhibitors/pharmacology
- RNA, Messenger/metabolism
- Rabbits
- Receptor, Bradykinin B1
- Receptors, Bradykinin/biosynthesis
- Receptors, Bradykinin/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Sulfones
- Up-Regulation/drug effects
- Up-Regulation/physiology
- Vasoconstrictor Agents/pharmacology
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Thierry Sabourin
- Centre Hospitalier Universitaire de Québec, Centre de Recherche du Pavillon l'Hôtel-Dieu de Québec, Québec Canada G1R 2J6
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35
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Fan J, Kapus A, Marsden PA, Li YH, Oreopoulos G, Marshall JC, Frantz S, Kelly RA, Medzhitov R, Rotstein OD. Regulation of Toll-like receptor 4 expression in the lung following hemorrhagic shock and lipopolysaccharide. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:5252-9. [PMID: 11994482 DOI: 10.4049/jimmunol.168.10.5252] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Toll-like receptor 4 (TLR4) has recently been shown to function as the major upstream sensor for LPS. In this study, a rodent model of lung injury following resuscitated hemorrhagic shock was used to examine the regulation of TLR4 gene and protein expression in vivo and in vitro. Intratracheal LPS alone induced a rapid reduction in whole lung TLR4 mRNA, an effect which is also observed in recovered alveolar macrophages. This effect appeared to be due to a lowering of TLR4 mRNA stability by approximately 69%. By contrast, while shock/resuscitation alone had no effect on TLR4 mRNA levels, it markedly altered the response to LPS. Specifically, antecedent shock prevented the LPS-induced reduction in TLR4 mRNA levels. This reversal was explained by the ability of prior resuscitated shock both to prevent the destabilization of TLR4 mRNA by LPS and also to augment LPS-stimulated TLR4 gene transcription compared with LPS alone. Oxidant stress related to shock/resuscitation appeared to contribute to the regulation of TLR4 mRNA, because supplementation of the resuscitation fluid with the antioxidant N-acetylcysteine reversed the ability of shock/resuscitation to preserve TLR4 mRNA levels following LPS. TLR4 protein levels in whole lung mirrored the changes seen for TLR4 mRNA. Considered in aggregate, these data suggest that levels of tlr4 expression are controlled both transcriptionally as well as posttranscriptionally through altered mRNA stability and that antecedent shock/resuscitation, a form of global ischemia/reperfusion, might influence regulation of this gene.
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MESH Headings
- Animals
- Bronchoalveolar Lavage Fluid/immunology
- Disease Models, Animal
- Drosophila Proteins
- Lipopolysaccharides/toxicity
- Lung/immunology
- Lung/metabolism
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Male
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/genetics
- Oxidative Stress/genetics
- Oxidative Stress/immunology
- RNA, Messenger/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/genetics
- Reperfusion Injury/genetics
- Reperfusion Injury/immunology
- Shock, Hemorrhagic/genetics
- Shock, Hemorrhagic/immunology
- Shock, Hemorrhagic/metabolism
- Toll-Like Receptor 4
- Toll-Like Receptors
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Affiliation(s)
- Jie Fan
- Department of Surgery, University Health Network, St. Michael's Hospital and University of Toronto, Toronto, Ontario, Canada
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Tarleton BJ, Wiley AA, Bartol FF. Neonatal estradiol exposure alters uterine morphology and endometrial transcriptional activity in prepubertal gilts. Domest Anim Endocrinol 2001; 21:111-25. [PMID: 11585701 DOI: 10.1016/s0739-7240(01)00106-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Porcine endometrial development between birth (postnatal day = PND 0) and PND 56 involves differentiation of glandular epithelium (GE) from luminal epithelium (LE) and estrogen receptor-alpha (ER) expression. Juvenile ER architecture evolves after birth, as stroma and nascent GE first express ER. Mature ER architecture is evident after PND 30, when stroma, GE and LE are ER-positive. When administered during discrete periods between PND 0 and 56, effects of estradiol-17beta valerate (EV) on the neonatal porcine uterus relate to endometrial ER architecture. Transient EV exposure from birth reduces embryo survival in pregnant adult gilts. Effects of EV, administered as juvenile endometrial ER architecture develops (P1, PND 0-13), or after mature ER architecture is established (P2, PND 42-55), were evaluated in uteri from gilts treated with corn oil or EV in P1 or P2 and hysterectomized on PND 100 without additional steroids (NSt), on PND 102 after EV on PND100-101 (EV2), or on PND 117 after EV2 followed by progesterone on PND 102-116 (EP). Neonatal EV reduced uterine weight (P < 0.02), size (P < 0.01), luminal protein content (P < 0.07), and percent incorporation of 3H-leucine into nondialyzable endometrial products in vitro (P < 0.01). Group (NSt, EV2, EP) -specific treatment effects detected for endometrial ER, progesterone receptor, uteroferrin, and/or retinol binding protein mRNA levels were frequently related to period (P1,P2). Results support the idea that estrogen-sensitive postnatal organizational events, including those defined, in part, by endometrial ER architecture, are likely components of genetic and epigenetic programs governing uterine morphogenesis and ontogeny of endometrial function in the pig.
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Affiliation(s)
- B J Tarleton
- Department of Animal and Dairy Sciences, Program in Cell and Molecular Biosciences, Auburn University, Auburn, Alabama 36849-5415, USA
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37
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Taylor AH, Pringle JH, Bell SC, Al-Azzawi F. Specific inhibition of estrogen receptor alpha function by antisense oligodeoxyribonucleotides. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2001; 11:219-31. [PMID: 11572599 DOI: 10.1089/108729001317022223] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have tested the effect of a range of antisense oligodeoxyribonucleotides (ODN) directed against the human estrogen receptor alpha (ERalpha) on ERalpha protein expression and function. Antisense ERalpha ODN transfected into the ERalpha-positive human breast carcinoma cell line MCF7-K2 showed variable responses dependent on the oligo used. The most active antisense ODN (oligo 7) decreased the levels of ERa protein by 61% as measured by Western blot analysis. Exogenous 17beta-estradiol (17beta-E2), but not 17alpha-E2, augmented this effect, with a threshold effect at 10(-8) M 17beta-E2. The inhibitory effect of antisense ERa oligo 7 was confirmed by measurement of functional ERalpha protein. 3H-17beta-E2 binding to MCF7 cell extracts was inhibited to approximately 40% of control values in the presence of oligo 7. Antisense-transfected MCF7-K2 cell cultures produced a further 30% binding reduction in the presence of exogenous 17beta-E2. An inhibitory effect on 17beta-E2-dependent cell function was confirmed by the demonstration that ERalpha oligo 7-transfected MCF7-K2 cells failed to exhibit 17beta-E2-stimulated cell proliferation. Exogenous 17beta-E2 enhanced the inhibitory effect of the antisense ODN by increasing ODN transfection efficiency but without ERalpha catabolism via the proteosomal pathway, suggesting an effect of 17beta-E2 on the plasma membrane and the existence of different ERalpha degradation pathways in the MCF7-K2 cell subclone. As 17beta-E2 had no effect on ERalpha protein degradation, we conclude that the observed reduction of ERalpha protein levels is due solely to the presence of the antisense ERalpha ODN. Antisense ERalpha ODN molecules, therefore, may form the basis of effective therapies against ERalpha-dependent malignancies.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Antineoplastic Agents, Hormonal/chemistry
- Antineoplastic Agents, Hormonal/pharmacology
- Binding, Competitive
- Biological Transport/drug effects
- Blotting, Western
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Cell Division/drug effects
- Cytoplasm/metabolism
- Drug Design
- Estradiol/metabolism
- Estrogen Receptor alpha
- Estrogens
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Microscopy, Fluorescence
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Oligodeoxyribonucleotides, Antisense/pharmacology
- Protein Binding
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Receptors, Estrogen/antagonists & inhibitors
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic/drug effects
- Transfection
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
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Affiliation(s)
- A H Taylor
- Department of Obstetrics & Gynaecology, Faculty of Medicine and Biological Sciences, University of Leicester, Leicestershire, England
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38
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Guo C, Savage L, Sarge KD, Park-Sarge OK. Gonadotropins decrease estrogen receptor-beta messenger ribonucleic acid stability in rat granulosa cells. Endocrinology 2001; 142:2230-7. [PMID: 11356667 DOI: 10.1210/endo.142.6.8102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously shown that the preovulatory LH surge down-regulates estrogen receptor-beta (ERbeta) messenger RNA (mRNA) levels selectively in the granulosa cells of preovulatory follicles. To gain insight into the underlying mechanisms, we examined whether the LH-induced loss of ERbeta mRNA expression in rat granulosa cells is attributable to the hormone-induced changes at the level of transcription and/or mRNA degradation. When the rate of ERbeta gene transcription was assessed in cultured granulosa cells, by nuclear run-off assays, we observed only a marginal effect of hCG on ERbeta gene transcription. In contrast, when ERbeta mRNA levels were estimated in granulosa cells that were cultured in the presence of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), an RNA synthesis inhibitor, we observed a significant inhibitory effect of human CG (hCG) on ERbeta mRNA expression at a magnitude similar to that observed in the absence of DRB. Forskolin (FSK) and 2-O-tetradecanol-phorbol-13-acetate (TPA), pharmacological agents that mimic LH actions in granulosa cells, also showed similar effects. Thus, these results suggest that LH decreases ERbeta mRNA expression in the granulosa cells of preovulatory follicles, primarily by destabilizing the preexisting ERbeta mRNA. We next determined the decay rate of the ERbeta mRNA in granulosa cells that were cultured in the presence of DRB and additional hCG, FSK, or TPA for various time periods, by estimating ERbeta mRNA levels, using semiquantitative RT-PCR assays and subsequent linear regression analyses. The half-life of the ERbeta mRNA in the presence of vehicle was 17.87 +/- 1.2 h (n = 4). hCG dramatically decreased the half-life of the ERbeta mRNA (4.85 +/- 0.49 h, n = 4). Similarly, both FSK and TPA decreased the half-life of the ERbeta mRNA to 3.57 +/- 0.31 h and 4.02 +/- 0.13 h, respectively. We extended these findings by examining whether the LH-induced down-regulation of the ERbeta mRNA is cycloheximide-sensitive. When granulosa cells were cultured in the presence of cycloheximide, a protein synthesis inhibitor, the inhibitory effects of hCG, FSK, and TPA on ERbeta mRNA levels were abolished. Similar results were obtained in the presence or absence of DRB, indicating that the hormone-induced destabilization of the ERbeta mRNA is coupled with translation processes. Taken together, our results demonstrate that LH decreases ERbeta mRNA expression, predominantly at the posttranscriptional level, in a cycloheximide-sensitive manner.
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Affiliation(s)
- C Guo
- Department of Physiology, University of Kentucky, Lexington 40536-0084, USA
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39
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Abstract
This review outlines the basic principles of a novel interrupted progestin HRT regimen in which estrogen is administered continuously, and progestin is given in a 3-days on, 3-days off pulsed fashion. The rationale for this regimen is to prevent receptor down-regulation and allow increased estrogen and progestin sensitivity during the progestin-free periods. Background information is provided including the reasons for poor patient acceptance of HRT, and the concerns of the potential association of HRT with breast and endometrial cancer. Experimental studies in the rat are described which provide evidence in support of the rationale for the interrupted progestin regimen. Clinically, two pilot studies examining symptom control, bleeding rates and safety of the interrupted progestin regimen, as well as preliminary results of a third study examining the usefulness of this regimen for addback therapy in GnRH agonist treated patients, are outlined. The preliminary results of phase III trials are presented. These clinical studies all demonstrated good symptom control, low bleeding rates, endometrial protection, and excellent patient acceptance. The combination of continuous estrogen with interrupted progestin appears to result in increased sensitivity to estrogen and progestin in estrogen responsive tissues. As a result, lower doses of estrogen and progestin may be used for HRT with good biological effects. Further clinical studies, preferably in prospective randomized trials, are required to demonstrate an advantage of this new regimen compared to continuous combined HRT.
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Affiliation(s)
- R F Casper
- Department of Obstetrics and Gynecology, The University of Toronto, Ont., Canada.
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40
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Nephew KP, Long X, Osborne E, Burke KA, Ahluwalia A, Bigsby RM. Effect of estradiol on estrogen receptor expression in rat uterine cell types. Biol Reprod 2000; 62:168-77. [PMID: 10611082 DOI: 10.1095/biolreprod62.1.168] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In rodent uterus, both up- and down-regulation of estrogen receptor alpha (ERalpha) messenger ribonucleic acid (mRNA) and protein levels by estradiol has been demonstrated; however, it is not known which of the uterine compartments (endometrial epithelium, stroma, myometrium) respond to estradiol with autoregulation of ERalpha. The purpose of the present study was to investigate and compare the kinetics and cell type-specific effects of estradiol on uterine ERalpha expression in immature and adult rats. Ovariectomized female rats were injected s.c. with sesame oil or estradiol-17beta. Uteri were collected and analyzed for changes in ERalpha mRNA using RNase protection assays (RPA) and in situ hybridization using radiolabeled probes specific for ERalpha. Immunohistochemical analysis was performed with a polyclonal antibody specific to ERalpha. Expression of ERalpha in the uterine epithelial cells decreased at 3 and 6 h after estradiol administration to immature and adult rats, respectively. At 24 h, ERalpha mRNA levels in the immature and mature rat uterus were higher than pretreatment levels but returned to baseline by 72 h. Pretreatment with cycloheximide did not block the 3-h repressive effect of estradiol, suggesting that the estradiol-induced decrease in ERalpha mRNA occurs independent of new protein synthesis. A decrease in ERalpha mRNA and protein was also observed in uterine epithelia at 3 and 6 h after an estradiol injection to immature and adult rats, and intensity of both the in situ hybridization signal and the immunostaining in the epithelium increased at 24 and 72 h. However, the periluminal stromal cells in the adult uterus and the majority of stromal cells of the immature uterus appeared to have increased ERalpha expression. The results indicate that down-regulation of ERalpha in the epithelia and up-regulation of stromal ERalpha play a role in early events associated with estradiol-induced cell proliferation of the uterine epithelia.
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Affiliation(s)
- K P Nephew
- Medical Sciences, Indiana University, School of Medicine, Bloomington, Indiana 47405, USA.
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41
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Taleghany N, Sarajari S, DonCarlos L, Gollapudi L, Oblinger M. Differential expression of estrogen receptor alpha and beta in rat dorsal root ganglion neurons. J Neurosci Res 1999. [DOI: 10.1002/(sici)1097-4547(19990901)57:5<603::aid-jnr3>3.0.co;2-r] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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