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Peralta M, Lizcano F. Endocrine Disruptors and Metabolic Changes: Impact on Puberty Control. Endocr Pract 2024; 30:384-397. [PMID: 38185329 DOI: 10.1016/j.eprac.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/27/2023] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
OBJECTIVE This study aims to explore the significant impact of environmental chemicals on disease development, focusing on their role in developing metabolic and endocrine diseases. The objective is to understand how these chemicals contribute to the increasing prevalence of precocious puberty, considering various factors, including epigenetic changes, lifestyle, and emotional disturbances. METHODS The study employs a comprehensive review of descriptive observational studies in both human and animal models to identify a degree of causality between exposure to environmental chemicals and disease development, specifically focusing on endocrine disruption. Due to ethical constraints, direct causation studies in human subjects are not feasible; therefore, the research relies on accumulated observational data. RESULTS Puberty is a crucial life period with marked physiological and psychological changes. The age at which sexual characteristics develop is changing in many regions. The findings indicate a correlation between exposure to endocrine-disrupting chemicals and the early onset of puberty. These chemicals have been shown to interfere with normal hormonal processes, particularly during critical developmental stages such as adolescence. The research also highlights the interaction of these chemical exposures with other factors, including nutritional history, social and lifestyle changes, and emotional stress, which together contribute to the prevalence of precocious puberty. CONCLUSION Environmental chemicals significantly contribute to the development of certain metabolic and endocrine diseases, particularly in the rising incidence of precocious puberty. Although the evidence is mainly observational, it adequately justifies regulatory actions to reduce exposure risks. Furthermore, these findings highlight the urgent need for more research on the epigenetic effects of these chemicals and their wider impact on human health, especially during vital developmental periods.
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Affiliation(s)
- Marcela Peralta
- Center of Biomedical Investigation Universidad de La Sabana, CIBUS, Chía, Colombia
| | - Fernando Lizcano
- Center of Biomedical Investigation Universidad de La Sabana, CIBUS, Chía, Colombia; Department of Endocrinology, Diabetes and Nutrition, Fundación CardioInfantil-Instituto de Cardiología, Bogotá, Colombia.
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2
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Lopez-Rodriguez D, Franssen D, Bakker J, Lomniczi A, Parent AS. Cellular and molecular features of EDC exposure: consequences for the GnRH network. Nat Rev Endocrinol 2021; 17:83-96. [PMID: 33288917 DOI: 10.1038/s41574-020-00436-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/16/2020] [Indexed: 12/12/2022]
Abstract
The onset of puberty and the female ovulatory cycle are important developmental milestones of the reproductive system. These processes are controlled by a tightly organized network of neurotransmitters and neuropeptides, as well as genetic, epigenetic and hormonal factors, which ultimately drive the pulsatile secretion of gonadotropin-releasing hormone. They also strongly depend on organizational processes that take place during fetal and early postnatal life. Therefore, exposure to environmental pollutants such as endocrine-disrupting chemicals (EDCs) during critical periods of development can result in altered brain development, delayed or advanced puberty and long-term reproductive consequences, such as impaired fertility. The gonads and peripheral organs are targets of EDCs, and research from the past few years suggests that the organization of the neuroendocrine control of reproduction is also sensitive to environmental cues and disruption. Among other mechanisms, EDCs interfere with the action of steroidal and non-steroidal receptors, and alter enzymatic, metabolic and epigenetic pathways during development. In this Review, we discuss the cellular and molecular consequences of perinatal exposure (mostly in rodents) to representative EDCs with a focus on the neuroendocrine control of reproduction, pubertal timing and the female ovulatory cycle.
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Affiliation(s)
| | - Delphine Franssen
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Julie Bakker
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Alejandro Lomniczi
- Division of Neuroscience, Oregon National Primate Research Center (ONPRC), OHSU, OR, USA
| | - Anne-Simone Parent
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium.
- Department of Pediatrics, University Hospital Liège, Liège, Belgium.
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3
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Vastagh C, Csillag V, Solymosi N, Farkas I, Liposits Z. Gonadal Cycle-Dependent Expression of Genes Encoding Peptide-, Growth Factor-, and Orphan G-Protein-Coupled Receptors in Gonadotropin- Releasing Hormone Neurons of Mice. Front Mol Neurosci 2021; 13:594119. [PMID: 33551743 PMCID: PMC7863983 DOI: 10.3389/fnmol.2020.594119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/30/2020] [Indexed: 12/30/2022] Open
Abstract
Rising serum estradiol triggers the surge release of gonadotropin-releasing hormone (GnRH) at late proestrus leading to ovulation. We hypothesized that proestrus evokes alterations in peptidergic signaling onto GnRH neurons inducing a differential expression of neuropeptide-, growth factor-, and orphan G-protein-coupled receptor (GPCR) genes. Thus, we analyzed the transcriptome of GnRH neurons collected from intact, proestrous and metestrous GnRH-green fluorescent protein (GnRH-GFP) transgenic mice using Affymetrix microarray technique. Proestrus resulted in a differential expression of genes coding for peptide/neuropeptide receptors including Adipor1, Prokr1, Ednrb, Rtn4r, Nmbr, Acvr2b, Sctr, Npr3, Nmur1, Mc3r, Cckbr, and Amhr2. In this gene cluster, Adipor1 mRNA expression was upregulated and the others were downregulated. Expression of growth factor receptors and their related proteins was also altered showing upregulation of Fgfr1, Igf1r, Grb2, Grb10, and Ngfrap1 and downregulation of Egfr and Tgfbr2 genes. Gpr107, an orphan GPCR, was upregulated during proestrus, while others were significantly downregulated (Gpr1, Gpr87, Gpr18, Gpr62, Gpr125, Gpr183, Gpr4, and Gpr88). Further affected receptors included vomeronasal receptors (Vmn1r172, Vmn2r-ps54, and Vmn1r148) and platelet-activating factor receptor (Ptafr), all with marked downregulation. Patch-clamp recordings from mouse GnRH-GFP neurons carried out at metestrus confirmed that the differentially expressed IGF-1, secretin, and GPR107 receptors were operational, as their activation by specific ligands evoked an increase in the frequency of miniature postsynaptic currents (mPSCs). These findings show the contribution of certain novel peptides, growth factors, and ligands of orphan GPCRs to regulation of GnRH neurons and their preparation for the surge release.
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Affiliation(s)
- Csaba Vastagh
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Veronika Csillag
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary.,Faculty of Information Technology and Bionics, Roska Tamás Doctoral School of Sciences and Technology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Norbert Solymosi
- Centre for Bioinformatics, University of Veterinary Medicine, Budapest, Hungary
| | - Imre Farkas
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary.,Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
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Tang ZR, Zhang R, Lian ZX, Deng SL, Yu K. Estrogen-Receptor Expression and Function in Female Reproductive Disease. Cells 2019; 8:cells8101123. [PMID: 31546660 PMCID: PMC6830311 DOI: 10.3390/cells8101123] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 01/13/2023] Open
Abstract
Estrogen receptors (ER) include ER alpha, ER beta and new membrane receptor G protein-coupled receptor 30 (GPR30). Estrogen receptors are key receptors to maintain ovarian granulosa cell differentiation, follicle and oocyte growth and development, and ovulation function. The abnormal functions of estrogen, its receptors, and estradiol synthesis-related enzymes are closely related to clinical reproductive endocrine diseases, such as polycystic ovary syndrome (PCOS) and endometriosis (EMS). At present, hormone therapy is the main treatment for ovarian-related diseases, and a stable hormone environment is established by regulating ovarian function. In recent years, some estrogen-related drugs have made great progress, such as clomiphene, which is a nonsteroidal antiestrogen drug in clinical application. This article elaborates on the regulatory role of estrogen and its nuclear receptors and membrane receptors in oocyte development, especially female reproductive diseases related to the abnormal expression of estrogen and its receptors. We also highlighted the latest advances of treatment strategy for these diseases and the application of related targeted small molecule drugs in clinical research and treatment, so as to provide reference for the treatment of female reproductive diseases.
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Affiliation(s)
- Zi-Run Tang
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Rui Zhang
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Zheng-Xing Lian
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Shou-Long Deng
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Kun Yu
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
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5
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Tominna R, Chokr S, Feri M, Chuon T, Sinchak K. Plasma membrane G protein-coupled estrogen receptor 1 (GPER) mediates rapid estradiol facilitation of sexual receptivity through the orphanin-FQ-ORL-1 system in estradiol primed female rats. Horm Behav 2019; 112:89-99. [PMID: 30981690 DOI: 10.1016/j.yhbeh.2019.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/26/2019] [Accepted: 04/08/2019] [Indexed: 11/29/2022]
Abstract
In estradiol-primed nonreceptive ovariectomized rats, activation of G protein-coupled estrogen receptor 1 (GPER) in the arcuate nucleus of the hypothalamus (ARH) rapidly facilitates sexual receptivity (lordosis). Estradiol priming activates ARH β-endorphin (β-END) neurons that then activate medial preoptic (MPN) μ-opioid receptors (MOP) to inhibit lordosis. ARH infusion of non-esterified 17β-estradiol (E2) 47.5 h after 17β-estradiol benzoate (2 μg EB) priming deactivates MPN MOP and rapidly facilitates lordosis within 30 min via activation of GPER. Since it was unclear where GPERs were located in the neuron, we tested the hypothesis that GPER signaling is initiated at the plasma membrane. Membrane impermeable estradiol (17β-estradiol conjugated to biotin; E-Biotin) infused into the ARH of EB primed rats facilitated lordosis within 30 min, and MPN MOP was deactivated. These actions were blocked by pretreating with GPER antagonist, G-15. Further, we used cell fractionation and western blot techniques to demonstrate that GPER is expressed both in plasma membrane and cytosolic ARH fractions. In previous studies, the orphanin FQ/nociceptin-opioid receptor-like receptor-1 (OFQ/N-ORL-1) system mediated estradiol-only facilitation of lordosis. Therefore, we tested whether the OFQ/N-ORL-1 system mediates E-Biotin-GPER facilitation of lordosis. Pretreatment of UFP-101, an ORL-1 selective antagonist, blocked the facilitation of lordosis and deactivation of MPN MOP by ARH infusion of E-Biotin. Double-label immunohistochemistry revealed that GPER is expressed within approximately 70% of OFQ/N neurons. These data indicate that membrane GPER mediates the E2/E-Biotin facilitation of lordosis by inducing OFQ/N neurotransmission, which inhibits β-END neurotransmission to reduce MPN MOP activation.
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Affiliation(s)
- Reema Tominna
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States of America
| | - Sima Chokr
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States of America
| | - Micah Feri
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States of America
| | - Timbora Chuon
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States of America
| | - Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States of America.
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6
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Micevych PE, Sinchak K. Extranuclear signaling by ovarian steroids in the regulation of sexual receptivity. Horm Behav 2018; 104:4-14. [PMID: 29753716 PMCID: PMC6240501 DOI: 10.1016/j.yhbeh.2018.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Paul E Micevych
- Dept of Neurobiology, David Geffen School of Medicine at UCLA, Laboratory of Neuroendocrinology of the UCLA Brain Research Institute, United States
| | - Kevin Sinchak
- Dept of Biological Sciences, California State University, Long Beach, United States.
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7
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Kadokawa H, Pandey K, Onalenna K, Nahar A. Reconsidering the roles of endogenous estrogens and xenoestrogens: the membrane estradiol receptor G protein-coupled receptor 30 (GPR30) mediates the effects of various estrogens. J Reprod Dev 2018. [PMID: 29515057 PMCID: PMC6021614 DOI: 10.1262/jrd.2017-153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Estrone (E1) and estriol (E3) are considered “weak” estrogens, which exert suppressive effects through estrogen receptors α and β. However, recent studies have demonstrated that E1 and E3,
as well as estradiol (E2), suppress gonadotropin-releasing hormone-induced luteinizing hormone secretion from bovine gonadotrophs via G-protein-coupled receptor 30, which is expressed in
various reproductive organs. Currently, there is a lack of fundamental knowledge regarding E1 and E3, including their blood levels. In addition, xenoestrogens may remain in the body over
long time periods because of enterohepatic circulation. Therefore, it is time to reconsider the roles of endogenous estrogens and xenoestrogens for reproduction.
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Affiliation(s)
- Hiroya Kadokawa
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Kiran Pandey
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Kereilwe Onalenna
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Asrafun Nahar
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
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8
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Hadjimarkou MM, Vasudevan N. GPER1/GPR30 in the brain: Crosstalk with classical estrogen receptors and implications for behavior. J Steroid Biochem Mol Biol 2018; 176:57-64. [PMID: 28465157 DOI: 10.1016/j.jsbmb.2017.04.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 04/16/2017] [Accepted: 04/23/2017] [Indexed: 12/31/2022]
Abstract
The GPER1/GPR30 is a membrane estrogen receptor (mER) that binds 17β-estradiol (17β-E) with high affinity and is thought to play a role in cancer progression and cardiovascular health. Though widespread in the central nervous system, less is known about this receptor's function in the brain. GPER1 has been shown to activate kinase cascades and calcium flux within cells rapidly, thus fitting in with the idea of being a mER that mediates non-genomic signaling by estrogens. Signaling from GPER1 has been shown to improve spatial memory, possibly via release of neurotransmitters and generation of new spines on neurons in the hippocampus. In addition, GPER1 activation contributes to behaviors that denote anxiety and to social behaviors such as social memory and lordosis behavior in mice. In the male hippocampus, GPER1 activation has also been shown to phosphorylate the classical intracellular estrogen receptor (ER)α, suggesting that crosstalk with ERα is important in the display of these behaviors, many of which are absent in ERα-null mice. In this review, we present a number of categories of such crosstalk, using examples from literature. The function of GPER1 as an ERα collaborator or as a mER in different tissues is relevant to understanding both normal physiology and abnormal pathology, mediated by estrogen signaling.
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Affiliation(s)
- Maria M Hadjimarkou
- School of Humanities and Social Sciences, University of Nicosia, 1700 Nicosia, Cyprus.
| | - Nandini Vasudevan
- School of Biological Sciences, University of Reading, Reading, United Kingdom RG6 6AS, United Kingdom.
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9
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Lappano R, Maggiolini M. GPER is involved in the functional liaison between breast tumor cells and cancer-associated fibroblasts (CAFs). J Steroid Biochem Mol Biol 2018; 176:49-56. [PMID: 28249728 DOI: 10.1016/j.jsbmb.2017.02.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 02/02/2017] [Accepted: 02/23/2017] [Indexed: 12/17/2022]
Abstract
The aggressiveness of breast tumors is deeply influenced by the surrounding stroma. In this regard, the functional crosstalk between cancer cells and the tumor microenvironment has received considerable attention in recent years. Cancer-associated fibroblasts (CAFs) are active components of the tumor stroma as they play a main role in the initiation, progression, metastasis and recurrence of breast malignancy. Hence, a better understanding of the mechanisms through which host stroma may contribute to cancer development would lead to novel therapeutic approaches aimed to target both tumor cells and the adjacent microenvironment. The G protein estrogen receptor (GPER/GPR30) has been involved in estrogenic signaling in normal and malignant cells, including breast cancer. It is noteworthy that the potential of GPER to mediate stimulatory effects of estrogens has been also shown in CAFs derived from patients with breast tumors, suggesting that GPER may act at the cross-road between cancer cells and these important components of the tumor microenvironment. This review recapitulates recent findings underlying the breast tumor-promoting action of CAFs, in particular their functional liaison with breast cancer cells via GPER toward the occurrence of malignant features.
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Affiliation(s)
- Rosamaria Lappano
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy.
| | - Marcello Maggiolini
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy.
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10
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Phumsatitpong C, Moenter SM. Estradiol-Dependent Stimulation and Suppression of Gonadotropin-Releasing Hormone Neuron Firing Activity by Corticotropin-Releasing Hormone in Female Mice. Endocrinology 2018; 159:414-425. [PMID: 29069304 PMCID: PMC5761586 DOI: 10.1210/en.2017-00747] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 10/17/2017] [Indexed: 11/19/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) neurons are the final central regulators of reproduction, integrating various inputs that modulate fertility. Stress typically inhibits reproduction but can be stimulatory; stress effects can also be modulated by steroid milieu. Corticotropin-releasing hormone (CRH) released during the stress response may suppress reproduction independent of downstream glucocorticoids. We hypothesized CRH suppresses fertility by decreasing GnRH neuron firing activity. To test this, mice were ovariectomized (OVX) and either implanted with an estradiol capsule (OVX+E) or not treated further to examine the influence of estradiol on GnRH neuron response to CRH. Targeted extracellular recordings were used to record firing activity from green fluorescent protein-identified GnRH neurons in brain slices before and during CRH treatment; recordings were done in the afternoon when estradiol has a positive feedback effect to increase GnRH neuron firing. In OVX mice, CRH did not affect the firing rate of GnRH neurons. In contrast, CRH exhibited dose-dependent stimulatory (30 nM) or inhibitory (100 nM) effects on GnRH neuron firing activity in OVX+E mice; both effects were reversible. The dose-dependent effects of CRH appear to result from activation of different receptor populations; a CRH receptor type-1 agonist increased firing activity in GnRH neurons, whereas a CRH receptor type-2 agonist decreased firing activity. CRH and specific agonists also differentially regulated short-term burst frequency and burst properties, including burst duration, spikes/burst, and/or intraburst interval. These results indicate that CRH alters GnRH neuron activity and that estradiol is required for CRH to exert both stimulatory and inhibitory effects on GnRH neurons.
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Affiliation(s)
- Chayarndorn Phumsatitpong
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
| | - Suzanne M. Moenter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan 48109
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Otsuka M, Kadokawa H. GPR30 mediates estrone, estriol, and estradiol to suppress gonadotropin-releasing hormone-induced luteinizing hormone secretion in the anterior pituitary of heifers. J Reprod Dev 2017; 63:519-525. [PMID: 28781349 PMCID: PMC5649102 DOI: 10.1262/jrd.2017-035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Recent studies demonstrated that G-protein-coupled receptor 30 (GPR30) on the plasma membrane of gonadotroph cells mediates picomolar, but not nanomolar, levels of estradiol (E2) to rapidly suppress gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) secretion in the anterior pituitary (AP). While estrone (E1) and estriol (E3) are considered "weak" estrogens that exert suppressive effects through estrogen receptors α and β, it is conceivable that they also strongly suppress GnRH-induced LH secretion via GPR30. Both E1 and E3 are likely present within the blood at picomolar or nanomolar concentrations, indicating that such concentrations are sufficient to suppress GnRH-induced LH secretion. To evaluate this possibility, bovine AP cells were cultured under steroid-free conditions and then incubated with various concentrations (0.01 pM to 10 nM) of E2, E1, or E3, prior to stimulation with GnRH. Notably, GnRH-induced LH secretion from AP cells was inhibited by 1-100 pM E2, 1-10 pM E1, and 1-100 pM E3. GnRH-induced LH secretion from AP cells was not inhibited by lower (0.01-0.1 pM) or higher (1-10 nM) concentrations of E2, E1, and E3. These suppressive effects were inhibited by pre-treatment of AP cells with the GPR30 antagonist G36, but not with the estrogen receptor alpha antagonist. Treatment with E1 or E3 also yielded decreased cytoplasmic cAMP levels in cultured AP cells pre-treated with dopamine and phosphodiesterase inhibitors. Therefore, these results suggest that GPR30 mediates the suppressive effects of E1, E3, and E2 on GnRH-induced LH secretion from bovine AP.
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Affiliation(s)
- Midori Otsuka
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Hiroya Kadokawa
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan
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12
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Menad R, Fernini M, Smaï S, Bonnet X, Gernigon-Spychalowicz T, Moudilou E, Khammar F, Exbrayat JM. GPER1 in sand rat epididymis: Effects of seasonal variations, castration and efferent ducts ligation. Anim Reprod Sci 2017; 183:9-20. [PMID: 28688795 DOI: 10.1016/j.anireprosci.2017.06.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/31/2017] [Accepted: 06/21/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Rafik Menad
- Small Vertebrates Reproduction, Laboratory of Research on Arid Areas, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, DZ-16111 El Alia, Algiers, Algeria; Faculty of Sciences, Department of Natural and Life Sciences, Algiers University I, Algeria.
| | - Meriem Fernini
- Small Vertebrates Reproduction, Laboratory of Research on Arid Areas, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, DZ-16111 El Alia, Algiers, Algeria
| | - Souaâd Smaï
- Small Vertebrates Reproduction, Laboratory of Research on Arid Areas, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, DZ-16111 El Alia, Algiers, Algeria
| | - Xavier Bonnet
- CEBC, UMR-7372 CNRS ULR, 79360 Villiers en Bois France
| | - Thérèse Gernigon-Spychalowicz
- Small Vertebrates Reproduction, Laboratory of Research on Arid Areas, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, DZ-16111 El Alia, Algiers, Algeria
| | - Elara Moudilou
- University of Lyon, UMRS 449, Laboratory of General Biology, Catholic University of Lyon, Reproduction and Comparative Development/EPHE,10 place des archives, 69002 Lyon, France
| | - Farida Khammar
- Mammal Ecophysiology, Laboratory of Research on Arid Areas, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, DZ-16111 El Alia, Algiers, Algeria
| | - Jean-Marie Exbrayat
- University of Lyon, UMRS 449, Laboratory of General Biology, Catholic University of Lyon, Reproduction and Comparative Development/EPHE,10 place des archives, 69002 Lyon, France.
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13
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Vastagh C, Rodolosse A, Solymosi N, Liposits Z. Altered Expression of Genes Encoding Neurotransmitter Receptors in GnRH Neurons of Proestrous Mice. Front Cell Neurosci 2016; 10:230. [PMID: 27774052 PMCID: PMC5054603 DOI: 10.3389/fncel.2016.00230] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/22/2016] [Indexed: 11/13/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) neurons play a key role in the central regulation of reproduction. In proestrous female mice, estradiol triggers the pre-ovulatory GnRH surge, however, its impact on the expression of neurotransmitter receptor genes in GnRH neurons has not been explored yet. We hypothesized that proestrus is accompanied by substantial changes in the expression profile of genes coding for neurotransmitter receptors in GnRH neurons. We compared the transcriptome of GnRH neurons obtained from intact, proestrous, and metestrous female GnRH-GFP transgenic mice, respectively. About 1500 individual GnRH neurons were sampled from both groups and their transcriptome was analyzed using microarray hybridization and real-time PCR. In this study, changes in mRNA expression of genes involved in neurotransmitter signaling were investigated. Differential gene expression was most apparent in GABA-ergic (Gabbr1, Gabra3, Gabrb3, Gabrb2, Gabrg2), glutamatergic (Gria1, Gria2, Grin1, Grin3a, Grm1, Slc17a6), cholinergic (Chrnb2, Chrm4) and dopaminergic (Drd3, Drd4), adrenergic (Adra1b, Adra2a, Adra2c), adenosinergic (Adora2a, Adora2b), glycinergic (Glra), purinergic (P2rx7), and serotonergic (Htr1b) receptors. In concert with these events, expression of genes in the signaling pathways downstream to the receptors, i.e., G-proteins (Gnai1, Gnai2, Gnas), adenylate-cyclases (Adcy3, Adcy5), protein kinase A (Prkaca, Prkacb) protein kinase C (Prkca) and certain transporters (Slc1a4, Slc17a6, Slc6a17) were also changed. The marked differences found in the expression of genes involved in neurotransmitter signaling of GnRH neurons at pro- and metestrous stages of the ovarian cycle indicate the differential contribution of these neurotransmitter systems to the induction of the pre-ovulatory GnRH surge, the known prerequisite of the subsequent hormonal cascade inducing ovulation.
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Affiliation(s)
- Csaba Vastagh
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary
| | - Annie Rodolosse
- Functional Genomics Core, Institute for Research in Biomedicine (IRB Barcelona)Barcelona, Spain
| | - Norbert Solymosi
- Department of Animal Hygiene, Herd-Health and Veterinary Ethology, University of Veterinary MedicineBudapest, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary
- Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic UniversityBudapest, Hungary
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Ervin KSJ, Mulvale E, Gallagher N, Roussel V, Choleris E. Activation of the G protein-coupled estrogen receptor, but not estrogen receptor α or β, rapidly enhances social learning. Psychoneuroendocrinology 2015; 58:51-66. [PMID: 25957002 DOI: 10.1016/j.psyneuen.2015.04.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 04/03/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
Social learning is a highly adaptive process by which an animal acquires information from a conspecific. While estrogens are known to modulate learning and memory, much of this research focuses on individual learning. Estrogens have been shown to enhance social learning on a long-term time scale, likely via genomic mechanisms. Estrogens have also been shown to affect individual learning on a rapid time scale through cell-signaling cascades, rather than via genomic effects, suggesting they may also rapidly influence social learning. We therefore investigated the effects of 17β-estradiol and involvement of the estrogen receptors (ERs) using the ERα agonist propyl pyrazole triol, the ERβ agonist diarylpropionitrile, and the G protein-coupled ER 1 (GPER1) agonist G1 on the social transmission of food preferences (STFP) task, within a time scale that focused on the rapid effects of estrogens. General ER activation with 17β-estradiol resulted in a modest facilitation of social learning, with mice showing a preference up to 30min of testing. Specific activation of the GPER1 also rapidly enhanced social learning, with mice showing a socially learned preference up to 2h of testing. ERα activation instead shortened the expression of a socially learned food preference, while ERβ activation had little to no effects. Thus, rapid estrogenic modulation of social learning in the STFP may be the outcome of competing action at the three main receptors. Hence, estrogens' rapid effects on social learning likely depend on the specific ERs present in brain regions recruited during social learning.
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Affiliation(s)
- Kelsy Sharice Jean Ervin
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, Canada
| | - Erin Mulvale
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, Canada
| | - Nicola Gallagher
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, Canada
| | - Véronique Roussel
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, Canada
| | - Elena Choleris
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, Canada.
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15
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Prossnitz ER, Arterburn JB. International Union of Basic and Clinical Pharmacology. XCVII. G Protein-Coupled Estrogen Receptor and Its Pharmacologic Modulators. Pharmacol Rev 2015; 67:505-40. [PMID: 26023144 PMCID: PMC4485017 DOI: 10.1124/pr.114.009712] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Estrogens are critical mediators of multiple and diverse physiologic effects throughout the body in both sexes, including the reproductive, cardiovascular, endocrine, nervous, and immune systems. As such, alterations in estrogen function play important roles in many diseases and pathophysiological conditions (including cancer), exemplified by the lower prevalence of many diseases in premenopausal women. Estrogens mediate their effects through multiple cellular receptors, including the nuclear receptor family (ERα and ERβ) and the G protein-coupled receptor (GPCR) family (GPR30/G protein-coupled estrogen receptor [GPER]). Although both receptor families can initiate rapid cell signaling and transcriptional regulation, the nuclear receptors are traditionally associated with regulating gene expression, whereas GPCRs are recognized as mediating rapid cellular signaling. Estrogen-activated pathways are not only the target of multiple therapeutic agents (e.g., tamoxifen, fulvestrant, raloxifene, and aromatase inhibitors) but are also affected by a plethora of phyto- and xeno-estrogens (e.g., genistein, coumestrol, bisphenol A, dichlorodiphenyltrichloroethane). Because of the existence of multiple estrogen receptors with overlapping ligand specificities, expression patterns, and signaling pathways, the roles of the individual receptors with respect to the diverse array of endogenous and exogenous ligands have been challenging to ascertain. The identification of GPER-selective ligands however has led to a much greater understanding of the roles of this receptor in normal physiology and disease as well as its interactions with the classic estrogen receptors ERα and ERβ and their signaling pathways. In this review, we describe the history and characterization of GPER over the past 15 years focusing on the pharmacology of steroidal and nonsteroidal compounds that have been employed to unravel the biology of this most recently recognized estrogen receptor.
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Affiliation(s)
- Eric R Prossnitz
- Department of Internal Medicine (E.R.P.) and University of New Mexico Cancer Center (E.R.P., J.B.A.), The University of New Mexico Health Sciences Center, Albuquerque, New Mexico; and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico (J.B.A.)
| | - Jeffrey B Arterburn
- Department of Internal Medicine (E.R.P.) and University of New Mexico Cancer Center (E.R.P., J.B.A.), The University of New Mexico Health Sciences Center, Albuquerque, New Mexico; and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico (J.B.A.)
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16
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Chason RJ, Kang JH, Gerkowicz SA, Dufau ML, Catt KJ, Segars JH. GnRH agonist reduces estrogen receptor dimerization in GT1-7 cells: evidence for cross-talk between membrane-initiated estrogen and GnRH signaling. Mol Cell Endocrinol 2015; 404:67-74. [PMID: 25619861 PMCID: PMC4590284 DOI: 10.1016/j.mce.2015.01.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/18/2015] [Accepted: 01/19/2015] [Indexed: 12/27/2022]
Abstract
17β-estradiol (E2), a key participant on the initiation of the LH surge, exerts both positive and negative feedback on GnRH neurons. We sought to investigate potential interactions between estrogen receptors alpha (ERα) and beta (ERβ) and gonadotropin releasing hormone receptor (GnRH-R) in GT1-7 cells. Radioligand binding studies demonstrated a significant decrease in saturation E2 binding in cells treated with GnRH agonist. Conversely, there was a significant reduction in GnRH binding in GT1-7 cells treated with E2. In BRET(1) experiments, ERα-ERα dimerization was suppressed in GT1-7 cells treated with GnRH agonist (p < 0.05). There was no evidence of direct interaction between ERs and GnRH-R. This study provides the first evidence of reduced ERα homodimerization by GnRH agonist. Collectively, these findings demonstrate significant cross-talk between membrane-initiated GnRH and E2 signaling in GT1-7 cells.
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Affiliation(s)
- Rebecca J Chason
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 CRC, Room 1E-3140, 10 Center Drive, MSC 1109, Bethesda, MD 20892-1109, USA
| | - Jung-Hoon Kang
- Section on Molecular Endocrinology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510, USA
| | - Sabrina A Gerkowicz
- Department of Obstetrics and Gynecology, University of Miami, 1611 NW 12th Ave, Miami, FL 33136, USA
| | - Maria L Dufau
- Section on Molecular Endocrinology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510, USA
| | - Kevin J Catt
- Endocrinology and Reproduction Research Branch, Section on Hormonal Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - James H Segars
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 CRC, Room 1E-3140, 10 Center Drive, MSC 1109, Bethesda, MD 20892-1109, USA.
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Sinchak K, Dalhousay L, Sanathara N. Orphanin FQ-ORL-1 regulation of reproduction and reproductive behavior in the female. VITAMINS AND HORMONES 2015; 97:187-221. [PMID: 25677773 DOI: 10.1016/bs.vh.2014.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Orphanin FQ (OFQ/N) and its receptor, opioid receptor-like receptor-1 (ORL-1), are expressed throughout steroid-responsive limbic and hypothalamic circuits that regulate female ovarian hormone feedback and reproductive behavior circuits. The arcuate nucleus of the hypothalamus (ARH) is a brain region that expresses OFQ/N and ORL-1 important for both sexual behavior and modulating estradiol feedback loops. Within the ARH, the activation of the OFQ/N-ORL-1 system facilitates sexual receptivity (lordosis) through the inhibition of β-endorphin neuronal activity. Estradiol initially activates ARH β-endorphin neurons to inhibit lordosis. Simultaneously, estradiol upregulates coexpression of OFQ/N and progesterone receptors and ORL-1 in ARH β-endorphin neurons. Ovarian hormones regulate pre- and postsynaptic coupling of ORL-1 to its G protein-coupled signaling pathways. When the steroid-primed rat is nonreceptive, estradiol acts pre- and postsynaptically to decrease the ability of the OFQ/N-ORL-1 system to inhibit ARH β-endorphin neurotransmission. Conversely, when sexually receptive, ORL-1 signaling is restored to inhibit β-endorphin neurotransmission. Although steroid signaling that facilitates lordosis converges to deactivate ARH β-endorphin neurons, estradiol-only facilitation of lordosis requires the activation of ORL-1, but estradiol+progesterone does not, indicating that multiple circuits mediate ovarian hormone signaling to deactivate ARH β-endorphin neurons. Research on the role of OFQ/N-ORL-1 in ovarian hormone feedback loops is just beginning. In the rat, OFQ/N may act to terminate gonadotropin-releasing hormone and luteinizing hormone release under positive and negative feedbacks. In the ewe, it appears to directly inhibit gonadotropin-releasing hormone release to mediate progesterone-negative feedback. As a whole, the localization and actions of OFQ/N-ORL-1 system indicate that it may mediate the actions of estradiol and progesterone to synchronize reproductive behavior and ovarian hormone feedback loops.
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Affiliation(s)
- Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, California, USA.
| | - Lauren Dalhousay
- Department of Biological Sciences, California State University, Long Beach, California, USA
| | - Nayna Sanathara
- Department of Pharmacological Sciences, University of California, Irvine, California, USA
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Kwon O, Kang ES, Kim I, Shin S, Kim M, Kwon S, Oh SR, Ahn YS, Kim CH. GPR30 mediates anorectic estrogen-induced STAT3 signaling in the hypothalamus. Metabolism 2014; 63:1455-61. [PMID: 25200186 DOI: 10.1016/j.metabol.2014.07.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 07/12/2014] [Accepted: 07/29/2014] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Estrogen plays an important role in the control of energy balance in the hypothalamus. Leptin-independent STAT3 activation (i.e., tyrosine(705)-phosphorylation of STAT3, pSTAT3) in the hypothalamus is hypothesized as the primary mechanism of the estrogen-induced anorexic response. However, the type of estrogen receptor that mediates this regulation is unknown. We investigated the role of the G protein-coupled receptor 30 (GPR30) in estradiol (E2)-induced STAT3 activation in the hypothalamus. MATERIALS/METHODS Regulation of STAT3 activation by E2, G-1, a specific agonist of GPR30 and G-15, a specific antagonist of GPR30 was analyzed in vitro and in vivo. Effect of GPR30 activation on eating behavior was analyzed in vivo. RESULTS E2 stimulated pSTAT3 in cells expressing GPR30, but not expressing estrogen receptor ERα and ERβ. G-1 induced pSTAT3, and G-15 inhibited E2-induced pSTAT3 in primary cultures of hypothalamic neurons. A cerebroventricular injection of G-1 increased pSTAT3 in the arcuate nucleus of mice, which was associated with a decrease in food intake and body weight gain. CONCLUSIONS These results suggest that GPR30 is the estrogen receptor that mediates the anorectic effect of estrogen through the STAT3 pathway in the hypothalamus.
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Affiliation(s)
- Obin Kwon
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Seok Kang
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Insook Kim
- Division of Metabolic Disease, Department of Biomedical Science, National Institutes of Health, Osong, Korea
| | - Sora Shin
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Mijung Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
| | - Somin Kwon
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
| | - So Ra Oh
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Young Soo Ahn
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea.
| | - Chul Hoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea.
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19
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Non-classical effects of estradiol on cAMP responsive element binding protein phosphorylation in gonadotropin-releasing hormone neurons: mechanisms and role. Front Neuroendocrinol 2014; 35:31-41. [PMID: 23978477 DOI: 10.1016/j.yfrne.2013.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/29/2013] [Accepted: 08/12/2013] [Indexed: 12/17/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) is produced by a heterogenous neuronal population in the hypothalamus to control pituitary gonadotropin production and reproductive function in all mammalian species. Estradiol is a critical component for the communication between the gonads and the central nervous system. Resolving the mechanisms by which estradiol modulates GnRH neurons is critical for the understanding of how fertility is regulated. Extensive studies during the past decades have provided compelling evidence that estradiol has the potential to alter the intracellular signal transduction mechanisms. The common target of many signaling pathways is the phosphorylation of a key transcription factor, the cAMP response element binding protein (CREB). This review first addresses the aspects of estradiol action on CREB phosphorylation (pCREB) in GnRH neurons. Secondly, this review considers the receptors and signaling network that regulates estradiol's action on pCREB within GnRH neurons and finally it summarizes the physiological significance of CREB to estrogen feedback.
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20
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Anchan D, Gafur A, Sano K, Ogawa S, Vasudevan N. Activation of the GPR30 receptor promotes lordosis in female mice. Neuroendocrinology 2014; 100:71-80. [PMID: 25012534 DOI: 10.1159/000365574] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 06/26/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Estrogens are important effectors of reproduction and are critical for upregulating female reproductive behavior or lordosis in females. In addition to the importance of transcriptional regulation of genes by 17β-estradiol-bound estrogen receptors (ER), extranuclear signal transduction cascades such as protein kinase A (PKA) are also important in regulating female sexual receptivity. GPR30 (G-protein coupled receptor 30), also known as GPER1, a putative membrane ER (mER), is a G protein-coupled receptor that binds 17β-estradiol with an affinity that is similar to that possessed by the classical nuclear ER and activates both PKA and extracellular-regulated kinase signaling pathways. The high expression of GPR30 in the ventromedial hypothalamus, a region important for lordosis behavior as well as kinase cascades activated by this receptor, led us to hypothesize that GPR30 may regulate lordosis behavior in female rodents. METHOD In this study, we investigated the ability of G-1, a selective agonist of GPR30, to regulate lordosis in the female mouse by administering this agent prior to progesterone in an estradiol-progesterone priming paradigm prior to testing with stud males. RESULTS As expected, 17β-estradiol benzoate (EB), but not sesame oil, increased lordosis behavior in female mice. G-1 also increased lordosis behavior in female mice and decreased the number of rejective responses towards male mice, similar to the effect of EB. The selective GPR30 antagonist G-15 blocked these effects. CONCLUSION This study demonstrates that activation of the mER GPR30 stimulates social behavior in a rodent model in a manner similar to EB.
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Affiliation(s)
- Divya Anchan
- Neuroscience Program, Tulane University, New Orleans, La., USA
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21
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Meitzen J, Luoma JI, Boulware MI, Hedges VL, Peterson BM, Tuomela K, Britson KA, Mermelstein PG. Palmitoylation of estrogen receptors is essential for neuronal membrane signaling. Endocrinology 2013; 154:4293-304. [PMID: 24008343 PMCID: PMC3800757 DOI: 10.1210/en.2013-1172] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In addition to activating nuclear estrogen receptor signaling, 17β-estradiol can also regulate neuronal function via surface membrane receptors. In various brain regions, these actions are mediated by the direct association of estrogen receptors (ERs) activating metabotropic glutamate receptors (mGluRs). These ER/mGluR signaling partners are organized into discrete functional microdomains via caveolin proteins. A central question that remains concerns the underlying mechanism by which these subpopulations of ERs are targeted to the surface membrane. One candidate mechanism is S-palmitoylation, a posttranscriptional modification that affects the subcellular distribution and function of the modified protein, including promoting localization to membranes. Here we test for the role of palmitoylation and the necessity of specific palmitoylacyltransferase proteins in neuronal membrane ER action. In hippocampal neurons, pharmacological inhibition of palmitoylation eliminated 17β-estradiol-mediated phosphorylation of cAMP response element-binding protein, a process dependent on surface membrane ERs. In addition, mutation of the palmitoylation site on estrogen receptor (ER) α blocks ERα-mediated cAMP response element-binding protein phosphorylation. Similar results were obtained after mutation of the palmitoylation site on ERβ. Importantly, mutation of either ERα or ERβ did not affect the ability of the reciprocal ER to signal at the membrane. In contrast, membrane ERα and ERβ signaling were both dependent on the expression of the palmitoylacyltransferase proteins DHHC-7 and DHHC-21. Neither mGluR activity nor caveolin or ER expression was affected by knockdown of DHHC-7 and DHHC-21. These data collectively suggest discrete mechanisms that regulate specific isoform or global membrane ER signaling in neurons separate from mGluR activity or nuclear ER function.
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Affiliation(s)
- John Meitzen
- PhD, Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Laboratories, Campus Box 7617, Raleigh, North Carolina 27695.
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22
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Ruiz-Palmero I, Hernando M, Garcia-Segura LM, Arevalo MA. G protein-coupled estrogen receptor is required for the neuritogenic mechanism of 17β-estradiol in developing hippocampal neurons. Mol Cell Endocrinol 2013; 372:105-15. [PMID: 23545157 DOI: 10.1016/j.mce.2013.03.018] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 02/28/2013] [Accepted: 03/21/2013] [Indexed: 01/29/2023]
Abstract
Estradiol promotes neuritogenesis in developing hippocampal neurons by a mechanism involving the upregulation of neurogenin 3, a Notch-regulated transcription factor. In this study we have explored whether G-protein coupled estrogen receptor 1 (GPER) participates in this hormonal action. GPER agonists (17β-estradiol, G1, ICI 182,780) increased neurogenin 3 expression and neuritogenesis in mouse primary hippocampal neurons and this effect was blocked by the GPER antagonist G15 and by a siRNA for GPER. In addition, GPER agonists increased Akt phosphorylation in ser473, which is indicative of the activation of phosphoinositide-3-kinase (PI3K). G15 or GPER silencing prevented the estrogenic induction of Akt phosphorylation. Furthermore, the PI3K inhibitor wortmannin prevented the effect of G1 and estradiol on neurogenin 3 expression and the effect of estradiol on neuritogenesis. These findings suggest that GPER participates in the control of hippocampal neuritogenesis by a mechanism involving the activation of PI3K signaling.
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Neuroprotective Effects of Estradiol on Motoneurons in a Model of Rat Spinal Cord Embryonic Explants. Cell Mol Neurobiol 2013; 33:421-32. [DOI: 10.1007/s10571-013-9908-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/05/2013] [Indexed: 12/12/2022]
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Shi H, Kumar SPDS, Liu X. G protein-coupled estrogen receptor in energy homeostasis and obesity pathogenesis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:193-250. [PMID: 23317786 PMCID: PMC3632385 DOI: 10.1016/b978-0-12-386933-3.00006-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Obesity and its related metabolic diseases have reached a pandemic level worldwide. There are sex differences in the prevalence of obesity and its related metabolic diseases, with men being more vulnerable than women; however, the prevalence of these disorders increases dramatically in women after menopause, suggesting that sex steroid hormone estrogens play key protective roles against development of obesity and metabolic diseases. Estrogens are important regulators of several aspects of metabolism, including body weight and body fat, caloric intake and energy expenditure, and glucose and lipid metabolism in both males and females. Estrogens act in complex ways on their nuclear estrogen receptors (ERs) ERα and ERβ and transmembrane ERs such as G protein-coupled estrogen receptor. Genetic tools, such as different lines of knockout mouse models, and pharmacological agents, such as selective agonists and antagonists, are available to study function and signaling mechanisms of ERs. We provide an overview of the evidence for the physiological and cellular actions of ERs in estrogen-dependent processes in the context of energy homeostasis and body fat regulation and discuss its pathology that leads to obesity and related metabolic states.
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Affiliation(s)
- Haifei Shi
- Department of Biology, Center for Physiology and Neuroscience, Miami University, Oxford, Ohio, USA
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25
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Romanò N, Herbison AE. Activity-dependent modulation of gonadotrophin-releasing hormone neurone activity by acute oestradiol. J Neuroendocrinol 2012; 24:1296-303. [PMID: 22612621 DOI: 10.1111/j.1365-2826.2012.02342.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Oestradiol (E₂) exerts potent feedback actions upon gonadotrophin-releasing hormone (GnRH) neurones and part of this feedback action may occur through the rapid action of E₂. Using a transgenic GnRH-Pericam mouse line that allows real-time intracellular calcium concentrations ([Ca²⁺](i)) to be monitored in adult GnRH neurones in a brain slice preparation, we examined the acute effects of 100 pM-100 nM E₂ on [Ca²⁺](i) transients in spontaneously active GnRH neurones. Approximately 30% of GnRH neurones exhibit spontaneous [Ca²⁺](i) transients at a frequency greater than two transients/15 min in adult female mice. In these cells, treatment with an incremental 1, 10, 100 nM E₂ protocol or 100 pM E₂ alone resulted in the suppression or complete cessation of [Ca²⁺](i) transients in 15 of 18 (83%) GnRH neurones. This effect was mimicked by E₂ bound to albumin, suggesting a membrane site of action, and was maintained in oestrogen receptor β knockout mice, indicating that this receptor is not essential for the rapid suppression of [Ca²⁺](i) transients. These findings contrast with those GnRH neurones exhibiting very few or no [Ca²⁺](i) transients (< 2 transients/15 min) that exhibit the opposite response of being activated by acute E₂. A series of dual calcium-cell-attached electrical recordings showed that [Ca²⁺](i) transients were associated with GnRH neurone burst firing and that E₂ suppression or activation of [Ca²⁺](i) transients was mirrored by a depression or initiation of burst firing. Taken together, these studies demonstrate that the acute actions of E₂ on GnRH neurones are critically dependent upon their pattern of burst firing.
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Affiliation(s)
- Nicola Romanò
- CNRS, UMR-5203, Institut de Génomique Fonctionelle, Montpellier, France
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26
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Sinchak K, Wagner EJ. Estradiol signaling in the regulation of reproduction and energy balance. Front Neuroendocrinol 2012; 33:342-63. [PMID: 22981653 PMCID: PMC3496056 DOI: 10.1016/j.yfrne.2012.08.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/18/2012] [Accepted: 08/22/2012] [Indexed: 12/14/2022]
Abstract
Our knowledge of membrane estrogenic signaling mechanisms and their interactions that regulate physiology and behavior has grown rapidly over the past three decades. The discovery of novel membrane estrogen receptors and their signaling mechanisms has started to reveal the complex timing and interactions of these various signaling mechanisms with classical genomic steroid actions within the nervous system to regulate physiology and behavior. The activation of the various estrogenic signaling mechanisms is site specific and differs across the estrous cycle acting through both classical genomic mechanisms and rapid membrane-initiated signaling to coordinate reproductive behavior and physiology. This review focuses on our current understanding of estrogenic signaling mechanisms to promote: (1) sexual receptivity within the arcuate nucleus of the hypothalamus, (2) estrogen positive feedback that stimulates de novo neuroprogesterone synthesis to trigger the luteinizing hormone surge important for ovulation and estrous cyclicity, and (3) alterations in energy balance.
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Affiliation(s)
- Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840-9502, United States.
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27
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Miao YL, Williams CJ. Calcium signaling in mammalian egg activation and embryo development: the influence of subcellular localization. Mol Reprod Dev 2012; 79:742-56. [PMID: 22888043 DOI: 10.1002/mrd.22078] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 07/27/2012] [Indexed: 11/07/2022]
Abstract
Calcium (Ca(2+) ) signals drive the fundamental events surrounding fertilization and the activation of development in all species examined to date. Initial studies of Ca(2+) signaling at fertilization in marine animals were tightly linked to new discoveries of bioluminescent proteins and their use as fluorescent Ca(2+) sensors. Since that time, there has been rapid progress in our understanding of the key functions for Ca(2+) in many cell types and of the impact of cellular localization on Ca(2+) signaling pathways. In this review, which focuses on mammalian egg activation, we consider how Ca(2+) is regulated and stored at different stages of oocyte development and examine the functions of molecules that serve as both regulators of Ca(2+) release and effectors of Ca(2+) signals. We then summarize studies exploring how Ca(2+) directs downstream effectors mediating both egg activation and later signaling events required for successful preimplantation embryo development. Throughout this review, we focus attention on how localization of Ca(2+) signals influences downstream signaling events, and attempt to highlight gaps in our knowledge that are ripe for future research.
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Affiliation(s)
- Yi-Liang Miao
- Reproductive Medicine Group, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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28
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Arevalo MA, Ruiz-Palmero I, Scerbo MJ, Acaz-Fonseca E, Cambiasso MJ, Garcia-Segura LM. Molecular mechanisms involved in the regulation of neuritogenesis by estradiol: Recent advances. J Steroid Biochem Mol Biol 2012; 131:52-6. [PMID: 21971420 DOI: 10.1016/j.jsbmb.2011.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 09/19/2011] [Accepted: 09/21/2011] [Indexed: 12/13/2022]
Abstract
This review analyzes the signaling mechanisms activated by estradiol to regulate neuritogenesis in several neuronal populations. Estradiol regulates axogenesis by the activation of the mitogen activated protein kinase (MAPK) cascade through estrogen receptor α located in the plasma membrane. In addition, estradiol regulates MAPK signaling via the activation of protein kinase C and by increasing the expression of brain derived neurotrophic factor and tyrosine kinase receptor B. Estradiol also interacts with the signaling of insulin-like growth factor-I receptor through estrogen receptor α, modulating the phosphoinositide-3 kinase signaling pathway, which contributes to the stabilization of microtubules. Finally, estradiol modulates dendritogenesis by the inhibition of Notch signaling, by a mechanism that, at least in hippocampal neurons, is mediated by G-protein coupled receptor 30. This article is part of a Special Issue entitled 'Neurosteroids'.
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29
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Ren J, Wu JH. 17β-estradiol rapidly activates calcium release from intracellular stores via the GPR30 pathway and MAPK phosphorylation in osteocyte-like MLO-Y4 cells. Calcif Tissue Int 2012; 90:411-9. [PMID: 22392527 DOI: 10.1007/s00223-012-9581-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 02/11/2012] [Indexed: 10/28/2022]
Abstract
Estrogen regulates critical cellular functions, and its deficiency initiates bone turnover and the development of bone mass loss in menopausal females. Recent studies have demonstrated that 17β-estradiol (E(2)) induces rapid non-genomic responses that activate downstream signaling molecules, thus providing a new perspective to understand the relationship between estrogen and bone metabolism. In this study, we investigated rapid estrogen responses, including calcium release and MAPK phosphorylation, in osteocyte-like MLO-Y4 cells. E(2) elevated [Ca(2+)]( i ) and increased Ca(2+) oscillation frequency in a dose-dependent manner. Immunolabeling confirmed the expression of three estrogen receptors (ERα, ERβ, and G protein-coupled receptor 30 [GPR30]) in MLO-Y4 cells and localized GPR30 predominantly to the plasma membrane. E(2) mobilized calcium from intracellular stores, and the use of selective agonist(s) for each ER showed that this was mediated mainly through the GPR30 pathway. MAPK phosphorylation increased in a biphasic manner, with peaks occurring after 7 and 60 min. GPR30 and classical ERs showed different temporal effects on MAPK phosphorylation and contributed to MAPK phosphorylation sequentially. ICI182,780 inhibited E(2) activation of MAPK at 7 min, while the GPR30 agonist G-1 and antagonist G-15 failed to affect MAPK phosphorylation levels. G-1-mediated MAPK phosphorylation at 60 min was prevented by prior depletion of calcium stores. Our data suggest that E(2) induces the non-genomic responses Ca(2+) release and MAPK phosphorylation to regulate osteocyte function and indicate that multiple receptors mediate rapid E(2) responses.
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Affiliation(s)
- Jian Ren
- Imaging and Characterization Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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30
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Kenealy BP, Terasawa E. Rapid direct action of estradiol in GnRH neurons: findings and implications. Front Endocrinol (Lausanne) 2012; 2:106. [PMID: 22654841 PMCID: PMC3356072 DOI: 10.3389/fendo.2011.00106] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 12/06/2011] [Indexed: 12/27/2022] Open
Abstract
Estradiol plays a pivotal role in the control of gonadotropin-releasing hormone (GnRH) neuronal function and female reproduction. While positive and negative feedback actions of estradiol that enhance and suppress release of GnRH and LH are primarily mediated through estrogen receptor alpha located in interneurons, a series of recent studies in our laboratory indicate that rapid excitatory actions of estradiol also directly modify GnRH neuronal activity. We observed this phenomenon in cultured primate GnRH neurons, but similar rapid direct actions of estradiol are also described in cultured GnRH neurons and green fluorescent protein-labeled GnRH neurons of mice. Importantly, rapid direct action of estradiol in GnRH neurons is mediated through membrane or membrane associated receptors, such as GPR30, STX-sensitive receptors, and ERβ. In this review, possible implications of this rapid estradiol action in GnRH neurons are discussed.
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Affiliation(s)
- Brian P. Kenealy
- Wisconsin National Primate Research Center, University of WisconsinMadison, WI, USA
| | - E. Terasawa
- Wisconsin National Primate Research Center, University of WisconsinMadison, WI, USA
- Department of Pediatrics, University of WisconsinMadison, WI, USA
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31
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Abstract
That oestradiol can have both negative- and positive-feedback actions upon the release of gonadotrophin-releasing hormone (GnRH) has been understood for decades. The vast majority of studies have investigated the effects of in vivo oestrogen administration. In the past decade, evidence has accumulated in many neuronal and non-neuronal systems indicating that, in addition to traditional genomic action via transcription factor receptors, steroids can also initiate effects rapidly via signalling cascades typically associated with the cell membrane. Here, we review work examining the rapid actions of oestradiol on GnRH neurones, addressing the questions of dose dependence, receptor subtypes, signalling cascades and intrinsic and synaptic properties that are rapidly modulated by this steroid.
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Affiliation(s)
- S M Moenter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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32
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Nilsson BO, Olde B, Leeb-Lundberg LMF. G protein-coupled oestrogen receptor 1 (GPER1)/GPR30: a new player in cardiovascular and metabolic oestrogenic signalling. Br J Pharmacol 2011; 163:1131-9. [PMID: 21250980 DOI: 10.1111/j.1476-5381.2011.01235.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Oestrogens are important sex hormones central to health and disease in both genders that have protective effects on the cardiovascular and metabolic systems. These hormones act in complex ways via both genomic and non-genomic mechanisms. The genomic mechanisms are relatively well characterized, whereas the non-genomic ones are only beginning to be explored. Two oestrogen receptors (ER), ERα and ERβ, have been described that act as nuclear transcription factors but can also associate with the plasma membrane and influence cytosolic signalling. ERα has been shown to mediate both anti-atherogenic effects and pro-survival effects in pancreatic β-cells. In recent years, a third membrane-bound ER has emerged, G protein-coupled receptor 30 or G protein-coupled oestrogen receptor 1 (GPER1), which mediates oestrogenic responses in cardiovascular and metabolic regulation. Both GPER1 knock-out models and pharmacological agents are now available to study GPER1 function. These tools have revealed that GPER1 activation may have several beneficial effects in the cardiovascular system including vasorelaxation, inhibition of smooth muscle cell proliferation, and protection of the myocardium against ischaemia/reperfusion injury, and in the metabolic system including stimulation of insulin release and protection against pancreatic β-cell apoptosis. Thus, GPER1 is emerging as a candidate therapeutic target in both cardiovascular and metabolic disease.
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Affiliation(s)
- Bengt-Olof Nilsson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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Hofmeister MV, Damkier HH, Christensen BM, Olde B, Fredrik Leeb-Lundberg LM, Fenton RA, Praetorius HA, Praetorius J. 17β-Estradiol induces nongenomic effects in renal intercalated cells through G protein-coupled estrogen receptor 1. Am J Physiol Renal Physiol 2011; 302:F358-68. [PMID: 21993891 DOI: 10.1152/ajprenal.00343.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Steroid hormones such as 17β-estradiol (E2) are known to modulate ion transporter expression in the kidney through classic intracellular receptors. Steroid hormones are also known to cause rapid nongenomic responses in a variety of nonrenal tissues. However, little is known about renal short-term effects of steroid hormones. Here, we studied the acute actions of E2 on intracellular Ca(2+) signaling in isolated distal convoluted tubules (DCT2), connecting tubules (CNT), and initial cortical collecting ducts (iCCD) by fluo 4 fluorometry. Physiological concentrations of E2 induced transient increases in intracellular Ca(2+) concentration ([Ca(2+)](i)) in a subpopulation of cells. The [Ca(2+)](i) increases required extracellular Ca(2+) and were inhibited by Gd(3+). Strikingly, the classic E2 receptor antagonist ICI 182,780 also increased [Ca(2+)](i), which is inconsistent with the activation of classic E2 receptors. G protein-coupled estrogen receptor 1 (GPER1 or GPR30) was detected in microdissected DCT2/CNT/iCCD by RT-PCR. Stimulation with the specific GPER1 agonist G-1 induced similar [Ca(2+)](i) increases as E2, and in tubules from GPER1 knockout mice, E2, G-1, and ICI 182,780 failed to induce [Ca(2+)](i) elevations. The intercalated cells showed both E2-induced concanamycin-sensitive H(+)-ATPase activity by BCECF fluorometry and the E2-mediated [Ca(2+)](i) increment. We propose that E2 via GPER1 evokes [Ca(2+)](i) transients and increases H(+)-ATPase activity in intercalated cells in mouse DCT2/CNT/iCCD.
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34
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Meyer MR, Clegg DJ, Prossnitz ER, Barton M. Obesity, insulin resistance and diabetes: sex differences and role of oestrogen receptors. Acta Physiol (Oxf) 2011; 203:259-69. [PMID: 21281456 DOI: 10.1111/j.1748-1716.2010.02237.x] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Obesity increases the risk of coronary artery disease through insulin resistance, diabetes, arterial hypertension and dyslipidemia. The prevalence of obesity has increased worldwide and is particularly high among middle-aged women and men. After menopause, women are at an increased risk to develop visceral obesity due to the loss of endogenous ovarian hormone production. Effects of oestrogens are classically mediated by the two nuclear oestrogen receptors (ERs) α and β. In addition, more recent research has shown that the intracellular transmembrane G-protein-coupled oestrogen receptor (GPER) originally designated as GPR30 also mediates some of the actions attributed to oestrogens. Oestrogen and its receptors are important regulators of body weight and insulin sensitivity not only in women but also in men as demonstrated by ER mutations in rodents and humans. This article reviews the role of sex hormones and ERs in the context of obesity, insulin sensitivity and diabetes as well as the related clinical issues in women and men.
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Affiliation(s)
- M R Meyer
- Molecular Internal Medicine, University of Zurich, Switzerland
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35
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Abstract
Estrogens mediate profound effects throughout the body and regulate physiological and pathological processes in both women and men. The low prevalence of many diseases in premenopausal women is attributed to the presence of 17β-estradiol, the predominant and most potent endogenous estrogen. In addition to endogenous estrogens, several man-made and plant-derived molecules, such as bisphenol A and genistein, also exhibit estrogenic activity. Traditionally, the actions of 17β-estradiol are ascribed to two nuclear estrogen receptors (ERs), ERα and ERβ, which function as ligand-activated transcription factors. However, 17β-estradiol also mediates rapid signaling events via pathways that involve transmembrane ERs, such as G-protein-coupled ER 1 (GPER; formerly known as GPR30). In the past 10 years, GPER has been implicated in both rapid signaling and transcriptional regulation. With the discovery of GPER-selective ligands that can selectively modulate GPER function in vitro and in preclinical studies and with the use of Gper knockout mice, many more potential roles for GPER are being elucidated. This Review highlights the physiological roles of GPER in the reproductive, nervous, endocrine, immune and cardiovascular systems, as well as its pathological roles in a diverse array of disorders including cancer, for which GPER is emerging as a novel therapeutic target and prognostic indicator.
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Affiliation(s)
- Eric R Prossnitz
- Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.
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36
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Kenealy BP, Keen KL, Terasawa E. Rapid action of estradiol in primate GnRH neurons: the role of estrogen receptor alpha and estrogen receptor beta. Steroids 2011; 76:861-6. [PMID: 21354432 PMCID: PMC3183999 DOI: 10.1016/j.steroids.2011.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 02/07/2011] [Accepted: 02/16/2011] [Indexed: 01/08/2023]
Abstract
Estrogens play a pivotal role in the control of female reproductive function. Recent studies using primate GnRH neurons derived from embryonic nasal placode indicate that 17β-estradiol (E(2)) causes a rapid stimulatory action. E(2) (1nM) stimulates firing activity and intracellular calcium ([Ca(2+)](i)) oscillations of primate GnRH neurons within a few min. E(2) also stimulates GnRH release within 10min. However, the classical estrogen receptors, ERα and ERβ, do not appear to play a role in E(2)-induced [Ca(2+)](i) oscillations or GnRH release, as the estrogen receptor antagonist, ICI 182,780, failed to block these responses. Rather, this rapid E(2) action is, at least in part, mediated by a G-protein coupled receptor GPR30. In the present study we further investigate the role of ERα and ERβ in the rapid action of E(2) by knocking down cellular ERα and ERβ by transfection of GnRH neurons with specific siRNA for rhesus monkey ERα and ERβ. Results indicate that cellular knockdown of ERα and ERβ failed to block the E(2)-induced changes in [Ca(2+)](i) oscillations. It is concluded that neither ERα nor ERβ is required for the rapid action of E(2) in primate GnRH neurons.
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Affiliation(s)
- B P Kenealy
- Wisconsin National Primate Research Center, Madison, WI 53715, USA
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37
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Ruiz-Palmero I, Simon-Areces J, Garcia-Segura LM, Arevalo MA. Notch/neurogenin 3 signalling is involved in the neuritogenic actions of oestradiol in developing hippocampal neurones. J Neuroendocrinol 2011; 23:355-64. [PMID: 21251092 DOI: 10.1111/j.1365-2826.2011.02110.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ovarian hormone oestradiol promotes neuritic outgrowth in different neuronal types, by mechanisms that remain elusive. Recent studies have shown that the Notch-regulated transcription factor neurogenin 3 controls neuritogenesis. In the present study, we assessed whether oestradiol regulates neurogenin 3 in primary hippocampal neurones. As expected, neuritogenesis was increased in the cultures treated with oestradiol. However, the neuritogenic action of oestradiol was not prevented by ICI 182,780, an antagonist of classical oestrogen receptors (ERs). Oestradiol decreased the expression of Hairy and Enhancer of Split-1, a Notch-regulated gene that negatively controls the expression on neurogenin 3. Furthermore, oestradiol increased the expression of neurogenin 3 and regulated its distribution between the neuronal cell nucleus and the cytoplasm. The effect of oestradiol on neurogenin 3 expression was not blocked by antagonists of classical nuclear ER-mediated transcription and was not imitated by selective agonists of nuclear ERs. By contrast, G1, a ligand of G protein receptor 30/G protein-coupled ER, fully reproduced the effect of oestradiol on neuritogenesis, neurogenin 3 expression and neurogenin 3 subcellular localisation. Moreover, knockdown of neurogenin 3 in neurones by transfection with small interference RNA for neurogenin 3 completely abrogated the neuritogenic actions of oestradiol and G1. These results suggest that oestradiol regulates neurogenin 3 in primary hippocampal neurones by a nonclassical steroid signalling mechanism, which involves the down-regulation of Notch activity and the activation of G protein receptor 30/G protein-coupled ER or of other unknown G1 targets. In addition, our findings indicate that neurogenin 3 participates in the neuritogenic mechanisms of oestradiol in hippocampal neurones.
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38
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Meitzen J, Mermelstein PG. Estrogen receptors stimulate brain region specific metabotropic glutamate receptors to rapidly initiate signal transduction pathways. J Chem Neuroanat 2011; 42:236-41. [PMID: 21458561 DOI: 10.1016/j.jchemneu.2011.02.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/14/2011] [Accepted: 02/15/2011] [Indexed: 11/17/2022]
Abstract
Estradiol and other steroid hormones modulate the nervous system and behavior on both acute and long-term time scales. Though estradiol was originally characterized as a regulator of gene expression through the action of nuclear estrogen receptors (ERs) that directly bind DNA, research over the past thirty years has firmly established that estradiol can bind to extra-nuclear ERs associated with the cellular membrane, producing changes in neurons through stimulation of various intracellular signaling pathways. Several studies have determined that the classical ERs, ERα and ERβ, mediate some of these fast-acting signaling pathways through activation of G proteins. Since ERα and ERβ are not G protein-coupled receptors, the mechanisms by which ERs can stimulate signal transduction pathways are a focus of recent research. Here we discuss recent studies illustrating one mechanism by which ERα and ERβ initiate these pathways: through direct association with metabotropic glutamate receptors (mGluRs). Estradiol binding to these membrane-localized estrogen receptors results in mGluR signaling independent of glutamate. ERs are organized with mGluRs into functional signaling microdomains via caveolin proteins. The pairing of ERs to specific mGluRs via caveolins is region specific, with ERs being linked to different mGluRs in hippocampal, striatal, and other neurons. It is becoming clear that ER signaling through mGluRs is one important mechanism by which estrogens can modulate neuron and glial physiology, ultimately impacting various aspects of nervous system function.
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Affiliation(s)
- John Meitzen
- Dept. of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
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39
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Arevalo MA, Ruiz-Palmero I, Simon-Areces J, Acaz-Fonseca E, Azcoitia I, Garcia-Segura LM. Estradiol meets notch signaling in developing neurons. Front Endocrinol (Lausanne) 2011; 2:21. [PMID: 22654797 PMCID: PMC3356013 DOI: 10.3389/fendo.2011.00021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 07/31/2011] [Indexed: 01/04/2023] Open
Abstract
The transmembrane receptor Notch, a master developmental regulator, controls gliogenesis, neurogenesis, and neurite development in the nervous system. Estradiol, acting as a hormonal signal or as a neurosteroid, also regulates these developmental processes. Here we review recent evidence indicating that estradiol and Notch signaling interact in developing hippocampal neurons by a mechanism involving the putative membrane receptor G protein-coupled receptor 30. This interaction is relevant for the control of neuronal differentiation, since the downregulation of Notch signaling by estradiol results in the upregulation of neurogenin 3, which in turn promotes dendritogenesis.
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Affiliation(s)
| | - Isabel Ruiz-Palmero
- Instituto Cajal, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Julia Simon-Areces
- Instituto Cajal, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | | | - Iñigo Azcoitia
- Facultad de Biología, Biología Celular, Universidad Complutense de MadridMadrid, Spain
| | - Luis Miguel Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones CientíficasMadrid, Spain
- *Correspondence: Luis Miguel Garcia-Segura, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avenida Doctor Arce 37, E-28002 Madrid, Spain. e-mail:
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40
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Hammond R, Gibbs RB. GPR30 is positioned to mediate estrogen effects on basal forebrain cholinergic neurons and cognitive performance. Brain Res 2010; 1379:53-60. [PMID: 21138734 DOI: 10.1016/j.brainres.2010.11.098] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/30/2010] [Accepted: 11/30/2010] [Indexed: 01/22/2023]
Abstract
Beneficial effects of estrogen therapy on cognitive performance diminish with age and time following the loss of ovarian function. This has led to the 'Window of Opportunity' hypothesis, which states that estrogen therapy must be administered within a limited period of time following menopause in order to be effective. Effects of estrogen therapy on cognitive performance are due, at least in part, to the effects on cholinergic afferents innervating the hippocampus and cortex, and it has been suggested that the loss of estrogen effect with age and time following menopause is due to a substantial reduction in the function of these projections. The mechanisms that underlie the effects are not clear. GPR30 is a novel G-protein coupled estrogen receptor that is expressed in the brain and other tissues. Our recent studies show that GPR30 is expressed in areas of the brain important for spatial learning, memory, and attention. In addition, GPR30 in expressed by the vast majority of cholinergic neurons in the basal forebrain, and appears to be an important regulator of basal forebrain cholinergic function. We hypothesize that GPR30 plays an important role in mediating direct effects of estradiol on basal forebrain cholinergic neurons, with corresponding effects on cognitive performance. Hence, GPR30 may be an important target for developing new therapies that can enhance or restore estrogen effects on cognitive performance in older women. Here we briefly review the cholinergic hypothesis and summarize our findings to date showing effects of a GPR30 agonist and antagonist on basal forebrain cholinergic function and cognitive performance.
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Affiliation(s)
- R Hammond
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA, USA.
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41
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Moenter SM. Identified GnRH neuron electrophysiology: a decade of study. Brain Res 2010; 1364:10-24. [PMID: 20920482 DOI: 10.1016/j.brainres.2010.09.066] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 09/15/2010] [Accepted: 09/17/2010] [Indexed: 12/27/2022]
Abstract
Over the past decade, the existence of transgenic mouse models in which reporter genes are expressed under the control of the gonadotropin-releasing hormone (GnRH) promoter has made possible the electrophysiological study of these cells. Here, we review the intrinsic and synaptic properties of these cells that have been revealed by these approaches, with a particular regard to burst generation. Advances in our understanding of neuromodulation of GnRH neurons and synchronization of this network are also discussed.
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Affiliation(s)
- Suzanne M Moenter
- Department of Molecular and Integrative Physiology, 7725 Med Sci II, 1301 E Catherine St., Ann Arbor, MI 48109-5622, USA.
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42
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Terasawa E, Kurian JR, Guerriero KA, Kenealy BP, Hutz ED, Keen KL. Recent discoveries on the control of gonadotrophin-releasing hormone neurones in nonhuman primates. J Neuroendocrinol 2010; 22:630-8. [PMID: 20456608 PMCID: PMC2908205 DOI: 10.1111/j.1365-2826.2010.02027.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Since Ernst Knobil proposed the concept of the gonadotrophin-releasing hormone (GnRH) pulse-generator in the monkey hypothalamus three decades ago, we have made significant progress in this research area with cellular and molecular approaches. First, an increase in pulsatile GnRH release triggers the onset of puberty. However, the question of what triggers the pubertal increase in GnRH is still unclear. GnRH neurones are already mature before puberty but GnRH release is suppressed by a tonic GABA inhibition. Our recent work indicates that blocking endogenous GABA inhibition with the GABA(A) receptor blocker, bicuculline, dramatically increases kisspeptin release, which plays an important role in the pubertal increase in GnRH release. Thus, an interplay between the GABA, kisspeptin, and GnRH neuronal systems appears to trigger puberty. Second, cultured GnRH neurones derived from the olfactory placode of monkey embryos exhibit synchronised intracellular calcium, [Ca(2+)](i), oscillations and release GnRH in pulses at approximately 60-min intervals after 14 days in vitro (div). During the first 14 div, GnRH neurones undergo maturational changes from no [Ca(2+)](i) oscillations and little GnRH release to the fully functional state. Recent work also shows GnRH mRNA expression increases during in vitro maturation. This mRNA increase coincides with significant demethylation of a CpG island in the GnRH 5'-promoter region. This suggests that epigenetic differentiation occurs during GnRH neuronal maturation. Third, oestradiol causes rapid, direct, excitatory action in GnRH neurones and this action of oestradiol appears to be mediated through a membrane receptor, such as G-protein coupled receptor 30.
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Affiliation(s)
- E Terasawa
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI 53715-1299, USA.
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Kang L, Zhang X, Xie Y, Tu Y, Wang D, Liu Z, Wang ZY. Involvement of estrogen receptor variant ER-alpha36, not GPR30, in nongenomic estrogen signaling. Mol Endocrinol 2010; 24:709-21. [PMID: 20197310 PMCID: PMC2852353 DOI: 10.1210/me.2009-0317] [Citation(s) in RCA: 196] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 01/22/2010] [Indexed: 02/08/2023] Open
Abstract
Accumulating evidence suggested that an orphan G protein-coupled receptor (GPR)30, mediates nongenomic responses to estrogen. The present study was performed to investigate the molecular mechanisms underlying GPR30 function. We found that knockdown of GPR30 expression in breast cancer SK-BR-3 cells down-regulated the expression levels of estrogen receptor (ER)-alpha36, a variant of ER-alpha. Introduction of a GPR30 expression vector into GPR30 nonexpressing cells induced endogenous ER-alpha36 expression, and cotransfection assay demonstrated that GPR30 activated the promoter activity of ER-alpha36 via an activator protein 1 binding site. Both 17beta-estradiol (E2) and G1, a compound reported to be a selective GPR30 agonist, increased the phosphorylation levels of the MAPK/ERK1/2 in SK-BR-3 cells, which could be blocked by an anti-ER-alpha36-specific antibody against its ligand-binding domain. G1 induced activities mediated by ER-alpha36, such as transcription activation activity of a VP16-ER-alpha36 fusion protein and activation of the MAPK/ERK1/2 in ER-alpha36-expressing cells. ER-alpha36-expressing cells, but not the nonexpressing cells, displayed high-affinity, specific E2 and G1 binding, and E2- and G1-induced intracellular Ca(2+) mobilization only in ER-alpha36 expressing cells. Taken together, our results demonstrated that previously reported activities of GPR30 in response to estrogen were through its ability to induce ER-alpha36 expression. The selective G protein-coupled receptor (GPR)30 agonist G1 actually interacts with ER-alpha36. Thus, the ER-alpha variant ER-alpha36, not GPR30, is involved in nongenomic estrogen signaling.
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Affiliation(s)
- Lianguo Kang
- Department of Medical Microbiology and Immunology, Creighton University Medical School, Omaha, Nebraska 68178, USA
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Burai R, Ramesh C, Shorty M, Curpan R, Bologa C, Sklar LA, Oprea T, Prossnitz ER, Arterburn JB. Highly efficient synthesis and characterization of the GPR30-selective agonist G-1 and related tetrahydroquinoline analogs. Org Biomol Chem 2010; 8:2252-9. [PMID: 20401403 DOI: 10.1039/c001307b] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The GPR30 agonist probe G-1 and structural analogs were efficiently synthesized using multicomponent or stepwise Sc(III)-catalyzed aza-Diels-Alder cyclization. Optimization of solvent and reaction temperature provided enhanced endo-diastereoselectivity.
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Affiliation(s)
- Ritwik Burai
- Department of Chemistry and Biochemistry MSC 3C, New Mexico State University, P.O. Box 30001, Las Cruces, New Mexico 88003, USA
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Lebesgue D, Reyna-Neyra A, Huang X, Etgen AM. GPR30 differentially regulates short latency responses of luteinising hormone and prolactin secretion to oestradiol. J Neuroendocrinol 2009; 21:743-52. [PMID: 19523168 PMCID: PMC2756443 DOI: 10.1111/j.1365-2826.2009.01893.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Rapid, nongenomic actions of 17beta-oestradiol (E(2)) on hypothalamic neurones that may be relevant to reproductive function were described decades ago. The orphan G protein-coupled receptor, GPR30, was recently shown to bind oestrogens and to trigger rapid signalling in vitro, and is expressed in several rat and human brain regions, including the hypothalamus. We used two complementary approaches to investigate the role of GPR30 in hypothalamic responses to E(2) that are relevant to reproductive physiology. Serial blood sampling after the acute administration of the selective GPR30 agonist G1 was used to assess the role of GPR30 in short latency negative-feedback inhibition of luteinising hormone (LH) secretion and facilitation of prolactin secretion in ovariohysterectomised female rats. In vivo RNA interference (RNAi), mediated by adeno-associated virus-expressing small hairpin RNA (shRNA) infused into the mediobasal hypothalamus, was used to study the effects of GPR30 knockdown on these rapid responses to E(2). Longer-term actions of E(2) on female sexual behaviour (lordosis) were also examined in female rats subjected to in vivo RNAi. Administration of E(2) or G1 triggered a short latency surge of prolactin secretion, and animals subjected to GPR30 RNAi showed significantly less E(2)-dependent prolactin release than animals receiving control virus. G1 did not mimic E(2) negative-feedback inhibition of LH secretion, and GPR30 RNAi did not interfere with E(2) suppression of LH or facilitation of lordosis behaviour. These findings suggest that activation of GPR30 promotes short latency prolactin secretion but does not mediate E(2) negative-feedback inhibition of LH secretion or E(2) facilitation of female reproductive behaviour.
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MESH Headings
- Animals
- Base Sequence
- Cells, Cultured
- Estradiol/administration & dosage
- Estradiol/pharmacology
- Female
- Humans
- Injections, Intraventricular
- Luteinizing Hormone/blood
- Luteinizing Hormone/metabolism
- Posture/physiology
- Prolactin/blood
- Prolactin/metabolism
- RNA, Small Interfering/administration & dosage
- RNA, Small Interfering/genetics
- RNA, Small Interfering/pharmacology
- Rats
- Rats, Sprague-Dawley
- Rats, Transgenic
- Reaction Time/drug effects
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/physiology
- Sexual Behavior, Animal/drug effects
- Time Factors
- Transduction, Genetic
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Affiliation(s)
- D Lebesgue
- Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
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Herbison AE. Rapid actions of oestrogen on gonadotropin-releasing hormone neurons; from fantasy to physiology? J Physiol 2009; 587:5025-30. [PMID: 19687121 DOI: 10.1113/jphysiol.2009.179838] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Oestradiol (E2) exerts critical homeostatic feedback effects upon gonadotropin-releasing hormone (GnRH) neurons to maintain fertility. In the female, E2 has both negative and positive feedback actions to suppress and stimulate GnRH neuron activity at different times of the ovarian cycle. This review summarizes reported rapid E2 effects on native embryonic and adult GnRH neurons and attempts to put them into a physiological perspective. Oestrogen has been shown to rapidly modulate multiple processes in embryonic and adult GnRH neurons including intracellular calcium levels, electrical activity and specific second messenger pathways, as well as GnRH secretion itself. Evaluation of in vivo data suggests that there is no essential role for rapid E2 actions in the positive feedback mechanism but that they may comprise part of the negative feedback pathway. Adult GnRH neurons are only likely to be exposed to E2 from the gonads via the circulation with appropriate physiological E2 concentrations in the rodent being 10-50 pM for negative feedback ranging up to 400 pM for positive feedback. Although most studies to date have examined the effects of supraphysiological E2 levels on GnRH neurons, there is accumulating evidence that rapid E2 actions may have a physiological role in suppressing GnRH neuron activity.
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Affiliation(s)
- Allan E Herbison
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Medical Sciences, PO Box 913, Dunedin, New Zealand.
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Biricova V, Laznickova A. Dendrimers: Analytical characterization and applications. Bioorg Chem 2009; 37:185-92. [PMID: 19703699 DOI: 10.1016/j.bioorg.2009.07.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 07/28/2009] [Accepted: 07/29/2009] [Indexed: 01/03/2023]
Abstract
This review focuses on analytical techniques used for separation and characterization of dendrimers and their derivatives. These macromolecules have been attractive material for a development of new drug carriers and imaging agents. They are also interesting for many biological and industrial applications. The review mentions a few of them.
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Affiliation(s)
- V Biricova
- Department of Biophysics and Physical Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, 500 05 Hradec Kralove, Czech Republic.
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