251
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Kumar R, Balhuizen A, Amisten S, Lundquist I, Salehi A. Insulinotropic and antidiabetic effects of 17β-estradiol and the GPR30 agonist G-1 on human pancreatic islets. Endocrinology 2011; 152:2568-79. [PMID: 21521748 DOI: 10.1210/en.2010-1361] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have recently shown that 17β-estradiol (E2) and the synthetic G protein-coupled receptor 30 (GPR30) ligand G-1 have antiapoptotic actions in mouse pancreatic islets, raising the prospect that they might exert beneficial effects also in human islets. The objective of the present study was to identify the expression of GPR30 in human islets and clarify the role of GPR30 in islet hormone secretion and β-cell survival. GPR30 expression was analyzed by confocal microscopy, Western blot, and quantitative PCR in islets from female and male donors. Hormone secretion, phosphatidylinositol hydrolysis, cAMP content, and caspase-3 activity in female islets were determined with conventional methods and apoptosis with the annexin-V method. Confocal microscopy revealed GPR30 expression in islet insulin, glucagon, and somatostatin cells. GPR30 mRNA and protein expression was markedly higher in female vs. male islets. An amplifying effect of G-1 or E2 on cAMP content and insulin secretion from isolated female islets was not influenced by the E2 genomic receptor (ERα and ERβ) antagonists ICI 182,780 and EM-652. Cytokine-induced (IL-1β plus TNFα plus interferon-γ) apoptosis in islets cultured for 24 h at 5 mmol/liter glucose was almost abolished by G-1 or E2 treatment and was not affected by the nuclear estrogen receptor antagonists. Concentration-response studies on female islets from healthy controls and type 2 diabetic subjects showed that both E2 and G-1 displayed important antidiabetic actions by improving glucose-stimulated insulin release while suppressing glucagon and somatostatin secretion. In view of these findings, we propose that small molecules activating GPR30 could be promising in the therapy of diabetes mellitus.
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MESH Headings
- Apoptosis/drug effects
- Cell Survival/drug effects
- Cyclopentanes/pharmacology
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Estradiol/pharmacology
- Estrogen Antagonists/pharmacology
- Female
- Gene Expression Regulation/drug effects
- Humans
- Hyperglycemia/metabolism
- Hypoglycemic Agents/pharmacology
- Insulin/metabolism
- Insulin Secretion
- Islets of Langerhans/drug effects
- Islets of Langerhans/metabolism
- Islets of Langerhans/pathology
- Male
- Molecular Targeted Therapy
- Oligonucleotide Array Sequence Analysis
- Organ Culture Techniques
- Quinolines/pharmacology
- RNA, Messenger/metabolism
- Receptors, Estrogen/antagonists & inhibitors
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Second Messenger Systems/drug effects
- Sex Characteristics
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Affiliation(s)
- Rajesh Kumar
- Department of Clinical Science, Skåne Universitetssjukhus, Division of Islet Cell Physiology, Clinical Research Center, Building 91, Plan 11, Entrance 72, S-205 02 Malmö, Sweden
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252
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Meyer MR, Prossnitz ER, Barton M. The G protein-coupled estrogen receptor GPER/GPR30 as a regulator of cardiovascular function. Vascul Pharmacol 2011; 55:17-25. [PMID: 21742056 PMCID: PMC3216677 DOI: 10.1016/j.vph.2011.06.003] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 06/19/2011] [Accepted: 06/25/2011] [Indexed: 12/29/2022]
Abstract
Endogenous estrogens are important regulators of cardiovascular homeostasis in premenopausal women and delay the development of hypertension and coronary artery disease. These hormones act via three different estrogen receptors affecting both gene transcription and rapid signaling pathways in a complex interplay. In addition to the classical estrogen receptors ERα and ERβ, which are known mediators of estrogen-dependent vascular effects, a G protein-coupled estrogen receptor termed GPER that is expressed in the cardiovascular system has recently been identified. Endogenous human 17β-estradiol, selective estrogen receptor modulators (SERMs) including tamoxifen and raloxifene, and selective estrogen receptor downregulators (SERDs) such as ICI 182,780 are all agonists of GPER, which has been implicated in the regulation of vasomotor tone and protection from myocardial ischemia/reperfusion injury. As a result, understanding the individual role of ERα, ERβ, and GPER in cardiovascular function has become increasingly complex. With accumulating evidence that GPER is responsible for a variety of beneficial cardiovascular effects of estrogens, this receptor may represent a novel target to develop effective strategies for the treatment of cardiovascular diseases by tissue-specific, selective activation of estrogen-dependent molecular pathways devoid of side effects seen with conventional hormone therapy.
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Affiliation(s)
- Matthias R. Meyer
- Molecular Internal Medicine, University of Zurich, Zurich, Switzerland
- Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Eric R. Prossnitz
- Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Matthias Barton
- Molecular Internal Medicine, University of Zurich, Zurich, Switzerland
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253
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Hectors TLM, Vanparys C, van der Ven K, Martens GA, Jorens PG, Van Gaal LF, Covaci A, De Coen W, Blust R. Environmental pollutants and type 2 diabetes: a review of mechanisms that can disrupt beta cell function. Diabetologia 2011; 54:1273-90. [PMID: 21442161 DOI: 10.1007/s00125-011-2109-5] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 01/07/2011] [Indexed: 12/17/2022]
Abstract
The prevalence of diabetes mellitus is currently at epidemic proportions and it is estimated that it will increase even further over the next decades. Although genetic predisposition and lifestyle choices are commonly accepted reasons for the occurrence of type 2 diabetes, it has recently been suggested that environmental pollutants are additional risk factors for diabetes development and this review aims to give an overview of the current evidence for this. More specifically, because of the crucial role of pancreatic beta cells in the development and progression of type 2 diabetes, the present work summarises the known effects of several compounds on beta cell function with reference to mechanistic studies that have elucidated how these compounds interfere with the insulin secreting capacity of beta cells. Oestrogenic compounds, organophosphorus compounds, persistent organic pollutants and heavy metals are discussed, and a critical reflection on the relevance of the concentrations used in mechanistic studies relative to the levels found in the human population is given. It is clear that some environmental pollutants affect pancreatic beta cell function, as both epidemiological and experimental research is accumulating. This supports the need to develop a solid and structured platform to fully explore the diabetes-inducing potential of pollutants.
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Affiliation(s)
- T L M Hectors
- Department of Biology, Laboratory of Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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254
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Fitts JM, Klein RM, Powers CA. Tamoxifen regulation of bone growth and endocrine function in the ovariectomized rat: discrimination of responses involving estrogen receptor α/estrogen receptor β, G protein-coupled estrogen receptor, or estrogen-related receptor γ using fulvestrant (ICI 182780). J Pharmacol Exp Ther 2011; 338:246-54. [PMID: 21464335 DOI: 10.1124/jpet.110.173955] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Tamoxifen is a selective estrogen receptor (ER) modulator, but it is also a deactivating ligand for estrogen-related receptor-γ (ERRγ) and a full agonist for the G protein-coupled estrogen receptor (GPER). Fulvestrant is a selective ER down-regulator that lacks agonist effects on ERα/ERβ, is inactive on ERRγ, but acts as a full agonist on GPER. Fulvestrant effects on tamoxifen actions on uterine and somatic growth, bone, the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, and pituitary prolactin were analyzed to pharmacologically discriminate tamoxifen effects that may be mediated by ERα/ERβ versus ERRγ versus GPER. Ovariectomized rats received tamoxifen (0.6 mg/kg/daily) plus fulvestrant at 0, 3, 6, or 12 mg/kg/daily for 5 weeks; controls received vehicle or 6 mg/kg fulvestrant daily. Tamoxifen effects to increase uterine weight, decrease serum IGF-I, increase pituitary prolactin, and increase bone mineral density could be fully blocked by fulvestrant, indicating mediation by ERα/ERβ. Tamoxifen effects to decrease pituitary GH, tibia length, and body weight were only partially blocked by fulvestrant, indicating involvement of mechanisms unrelated to ERα/ERβ. Fulvestrant did not inhibit tamoxifen actions to reduce total pituitary protein, again indicating effects not mediated by ERα/ERβ. Tamoxifen actions to reduce serum GH were mimicked rather than inhibited by fulvestrant, pharmacological features consistent with GPER involvement. However, fulvestrant alone increased IGF-I and also blocked tamoxifen-evoked IGF-I decreases; thus fulvestrant effects on serum GH might reflect increased IGF-I feedback inhibition. Fulvestrant alone had no effect on the other parameters. The findings indicate that mechanisms unrelated to ERα/ERβ contribute to tamoxifen effects on body weight, bone growth, and pituitary function.
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Affiliation(s)
- James M Fitts
- Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA
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255
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Gao F, Ma X, Ostmann AB, Das SK. GPR30 activation opposes estrogen-dependent uterine growth via inhibition of stromal ERK1/2 and estrogen receptor alpha (ERα) phosphorylation signals. Endocrinology 2011; 152:1434-47. [PMID: 21303939 PMCID: PMC3060628 DOI: 10.1210/en.2010-1368] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Although estradiol-17β (E2)-regulated early and late phase uterine responses have been well defined, the molecular mechanisms linking the phases remain poorly understood. We have previously shown that E2-regulated early signals mediate cross talk with estrogen receptor (ER)-α to elicit uterine late growth responses. G protein-coupled receptor (GPR30) has been implicated in early nongenomic signaling mediated by E2, although its role in E2-dependent uterine biology is unclear. Using selective activation of GPR30 by G-1, we show here a new function of GPR30 in regulating early signaling events, including the inhibition of ERK1/2 and ERα (Ser118) phosphorylation signals and perturbation of growth regulation under the direction of E2 in the mouse uterus. We observed that GPR30 primarily localizes in the uterine epithelial cells, and its activation alters gene expression and mediates inhibition of ERK1/2 and ERα (Ser118) phosphorylation signals in the stromal compartment, suggesting a paracrine signaling is involved. Importantly, viral-driven manipulation of GPR30 or pharmacological inhibition of ERK1/2 activation effectively alters E2-dependent uterine growth responses. Overall, GPR30 is a negative regulator of ERα-dependent uterine growth in response to E2. Our work has uncovered a novel GPR30-regulated inhibitory event, which may be physiologically relevant in both normal and pathological situations to negatively balance ERα-dependent uterine growth regulatory functions induced by E2.
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Affiliation(s)
- Fei Gao
- Division of Reproductive Sciences, The Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, USA
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256
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Deschamps AM, Murphy E, Sun J. Estrogen receptor activation and cardioprotection in ischemia reperfusion injury. Trends Cardiovasc Med 2011; 20:73-8. [PMID: 21130949 DOI: 10.1016/j.tcm.2010.05.001] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Premenopausal females have a comparably lower incidence of cardiovascular disease than their male counterparts. Although estrogen and activation of estrogen receptors (ERs) have been found to contribute to female protection, the complex mechanisms involved are unclear. Besides altering gene transcription, estrogen could elicit its cardioprotective effect via ER-mediated nongenomic signaling pathways. In addition to the two classic nuclear ER isoforms, ERα and ERβ, a G-protein coupled ER (GPR30 or GPER) has been found to be expressed in cardiomyocytes and plays an acute cardioprotective role in ischemia reperfusion injury. By using isoform-specific ER knockout mouse models and/or their specific modulators, the mechanisms of the different ERs involved in cardioprotection have been explored. In this review, we will focus on the signaling pathways leading to cardioprotection in ischemia reperfusion injury after ER activation and discuss the possibility and promise of specific ER modulators to treat ischemic heart diseases.
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Affiliation(s)
- Anne M Deschamps
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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257
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Chen L, Mei XP, Gao CJ, Zhang GH, Sun XD. Histologic distribution, fragment cloning, and sequence analysis of g protein couple receptor 30 in rat submaxillary gland. Anat Rec (Hoboken) 2011; 294:706-11. [PMID: 21365775 DOI: 10.1002/ar.21349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 12/14/2010] [Accepted: 12/15/2010] [Indexed: 11/07/2022]
Abstract
Recent studies indicated that G protein couple receptor 30 (GPR30), a nongenomic estrogen receptor, is widely expressed in many organ systems inducing many quick reaction of estrogen. However, there was rare report about the expression of GPR30 in the salivary gland. In the present study, we investigated the distribution of GPR30 in rat submaxillary gland by means of immunohistochemistry and in situ hybridization. GPR30 core sequences were amplified by RT-PCR with total RNA extracted from rat submaxillary gland and were analyzed by sequencing with Sanger's method. The results showed that the epithelial cells of serous alveoli and granular convoluted duct in rat submaxillary gland displayed GPR30-immunoreactivity on the plasma membrane and cytoplasm. Moreover, GPR30 mRNA hybridization signals were also detected in the cytoplasm of the above cells. GPR30 cDNA sequence cloned from rat submaxillary gland is identical to that of GPR30 from rat paraventricular and supraoptic nucleus. In conclusion, the expression of GPR30 in the serous and granular epithelial cells of submaxillary gland indicates that submaxillary gland could also be a target organ rapidly responding to estrogen stimulus, and estrogen may be involved in the functional regulation of submaxillary gland.
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Affiliation(s)
- Lei Chen
- Department of Gynaecology and Obstetrics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
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258
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Ford J, Hajibeigi A, Long M, Hahner L, Gore C, Hsieh JT, Clegg D, Zerwekh J, Oz OK. GPR30 deficiency causes increased bone mass, mineralization, and growth plate proliferative activity in male mice. J Bone Miner Res 2011; 26:298-307. [PMID: 20734455 PMCID: PMC3179349 DOI: 10.1002/jbmr.209] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Estrogen regulation of the male skeleton was first clearly demonstrated in patients with aromatase deficiency or a mutation in the ERα gene. Estrogen action on the skeleton is thought to occur mainly through the action of the nuclear receptors ERα and ERβ. Recently, in vitro studies have shown that the G protein-coupled receptor GPR30 is a functional estrogen receptor (ER). GPR30-deficient mouse models have been generated to study the in vivo function of this protein; however, its in vivo role in the male skeleton remains underexplored. We have characterized size, body composition, and bone mass in adult male Gpr30 knockout (KO) mice and their wild-type (WT) littermates. Gpr30 KO mice weighed more and had greater nasal-anal length (p < .001). Both lean mass and percent body fat were increased in the KO mice. Femur length was greater in Gpr30 KO mice, as was whole-body, spine, and femoral areal bone mineral density (p < .01). Gpr30 KO mice showed increased trabecular bone volume (p < .01) and cortical thickness (p < .001). Mineralized surface was increased in Gpr30 KO mice (p < .05). Bromodeoxyuridine (BrdU) labeling showed greater proliferation in the growth plate of Gpr30 KO mice (p < .05). Under osteogenic culture conditions, Gpr30 KO femoral bone marrow cells produced fewer alkaline phosphatase-positive colonies in early differentiating osteoblast cultures but showed increased mineralized nodule deposition in mature osteoblast cultures. Serum insulin-like growth factor 1 (IGF-1) levels were not different. These data suggest that in male mice, GPR30 action contributes to regulation of bone mass, size, and microarchitecture by a mechanism that does not require changes in circulating IGF-1.
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Affiliation(s)
- Jeffery Ford
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9058, USA
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259
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Holm A, Baldetorp B, Olde B, Leeb-Lundberg LMF, Nilsson BO. The GPER1 agonist G-1 attenuates endothelial cell proliferation by inhibiting DNA synthesis and accumulating cells in the S and G2 phases of the cell cycle. J Vasc Res 2011; 48:327-35. [PMID: 21273787 DOI: 10.1159/000322578] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 10/30/2010] [Indexed: 12/29/2022] Open
Abstract
G protein-coupled receptor 30 (GPR30) or G protein-coupled estrogen receptor 1 (GPER1) is expressed in the vasculature, but the importance of vascular GPER1 remains to be clarified. Here we investigate effects of the GPER1 agonist G-1 on endothelial cell proliferation using mouse microvascular endothelial bEnd.3 cells. The bEnd.3 cells express mRNA for GPER1. The bEnd.3 cells expressed both ERα and ERβ immunoreactivities. Treatment with G-1 reduced DNA synthesis and cell number with IC(50) values of about 2 μM. GPER1 siRNA prevented G-1-induced attenuation of DNA synthesis. G-1 accumulated cells in S and G2 phases of the cell cycle, suggesting that G-1 blocks transition between G2 and M. G-1 had no effect on DNA synthesis in COS-7 cells only weakly expressing GPER1 mRNA. 17β-Estradiol had no effect on DNA synthesis in physiological concentrations (nM). The ER blocker ICI182780 reduced DNA synthesis with similar potency as G-1. Treatment with the ERK/MAP kinase inhibitor PD98059 had no effect on G-1-induced attenuation of DNA synthesis. G-1- induced antiproliferation was observed not only in bEnd.3 cells but also in human umbilical vein endothelial cells and HMEC-1 endothelial cells. We conclude that the GPER1 agonist G-1 attenuates endothelial cell proliferation via inhibition of DNA synthesis and by accumulation of cells in S and G2.
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Affiliation(s)
- Anders Holm
- Department of Experimental Medical Science, Lund University, Lund University Hospital, Lund, Sweden
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260
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Mauvais-Jarvis F. Estrogen and androgen receptors: regulators of fuel homeostasis and emerging targets for diabetes and obesity. Trends Endocrinol Metab 2011; 22:24-33. [PMID: 21109497 PMCID: PMC3011051 DOI: 10.1016/j.tem.2010.10.002] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 10/08/2010] [Accepted: 10/11/2010] [Indexed: 01/31/2023]
Abstract
Because of increasing life expectancy, the contribution of age-related estrogen or androgen deficiency to obesity and type 2 diabetes will become a new therapeutic challenge. This review integrates current concepts on the mechanisms through which estrogen receptors (ERs) and androgen receptor (AR) regulate energy homeostasis in rodents and humans. In females, estrogen maintains energy homeostasis via ERα and ERβ, by suppressing energy intake and lipogenesis, enhancing energy expenditure, and ameliorating insulin secretion and sensitivity. In males, testosterone is converted to estrogen and maintains fuel homeostasis via ERs and AR, which share related functions to suppress adipose tissue accumulation and improve insulin sensitivity. We suggest that ERs and AR could be potential targets in the prevention of age-related metabolic disorders.
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Affiliation(s)
- Franck Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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261
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Sandén C, Broselid S, Cornmark L, Andersson K, Daszkiewicz-Nilsson J, Mårtensson UEA, Olde B, Leeb-Lundberg LMF. G protein-coupled estrogen receptor 1/G protein-coupled receptor 30 localizes in the plasma membrane and traffics intracellularly on cytokeratin intermediate filaments. Mol Pharmacol 2010; 79:400-10. [PMID: 21149639 DOI: 10.1124/mol.110.069500] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
G protein-coupled receptor 30 [G protein-coupled estrogen receptor 1 (GPER1)], has been introduced as a membrane estrogen receptor and a candidate cancer biomarker and therapeutic target. However, several questions surround the subcellular localization and signaling of this receptor. In native cells, including mouse myoblast C(2)C(12) cells, Madin-Darby canine kidney epithelial cells, and human ductal breast epithelial tumor T47-D cells, G-1, a GPER1 agonist, and 17β-estradiol stimulated GPER1-dependent cAMP production, a defined plasma membrane (PM) event, and recruitment of β-arrestin2 to the PM. Staining of fixed and live cells showed that GPER1 was localized both in the PM and on intracellular structures. One such intracellular structure was identified as cytokeratin (CK) intermediate filaments, including those composed of CK7 and CK8, but apparently not endoplasmic reticulum, Golgi, or microtubules. Reciprocal coimmunoprecipitation of GPER1 and CKs confirmed an association of these proteins. Live staining also showed that the PM receptors constitutively internalize apparently to reach CK filaments. Receptor localization was supported using FLAG- and hemagglutinin-tagged GPER1. We conclude that GPER1-mediated stimulation of cAMP production and β-arrestin2 recruitment occur in the PM. Furthermore, the PM receptors constitutively internalize and localize intracellularly on CK. This is the first observation that a G protein-coupled receptor is capable of associating with intermediate filaments, which may be important for GPER1 regulation in epithelial cells and the relationship of this receptor to cancer.
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Affiliation(s)
- Caroline Sandén
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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262
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Börjesson AE, Lagerquist MK, Liu C, Shao R, Windahl SH, Karlsson C, Sjögren K, Movérare-Skrtic S, Antal MC, Krust A, Mohan S, Chambon P, Sävendahl L, Ohlsson C. The role of estrogen receptor α in growth plate cartilage for longitudinal bone growth. J Bone Miner Res 2010; 25:2690-700. [PMID: 20564247 DOI: 10.1002/jbmr.156] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 05/07/2010] [Accepted: 06/04/2010] [Indexed: 11/06/2022]
Abstract
Estrogens enhance skeletal growth during early sexual maturation, whereas high estradiol levels during late puberty result in growth plate fusion in humans. Although the growth plates do not fuse directly after sexual maturation in rodents, a reduction in growth plate height is seen by treatment with a high dose of estradiol. It is unknown whether the effects of estrogens on skeletal growth are mediated directly via estrogen receptors (ERs) in growth plate cartilage and/or indirectly via other mechanisms such as the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis. To determine the role of ERα in growth plate cartilage for skeletal growth, we developed a mouse model with cartilage-specific inactivation of ERα. Although mice with total ERα inactivation displayed affected longitudinal bone growth associated with alterations in the GH/IGF-1 axis, the skeletal growth was normal during sexual maturation in mice with cartilage-specific ERα inactivation. High-dose estradiol treatment of adult mice reduced the growth plate height as a consequence of attenuated proliferation of growth plate chondrocytes in control mice but not in cartilage-specific ERα(-/-) mice. Adult cartilage-specific ERα(-/-) mice continued to grow after 4 months of age, whereas growth was limited in control mice, resulting in increased femur length in 1-year-old cartilage-specific ERα(-/-) mice compared with control mice. We conclude that during early sexual maturation, ERα in growth plate cartilage is not important for skeletal growth. In contrast, it is essential for high-dose estradiol to reduce the growth plate height in adult mice and for reduction of longitudinal bone growth in elderly mice.
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Affiliation(s)
- Anna E Börjesson
- Centre for Bone and Arthritis Research, Institute of Medicine, University of Gothenburg, Sahlgrenska Academy, Göteborg, Sweden
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263
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Morimoto S, Morales A, Zambrano E, Fernandez-Mejia C. Sex steroids effects on the endocrine pancreas. J Steroid Biochem Mol Biol 2010; 122:107-13. [PMID: 20580673 DOI: 10.1016/j.jsbmb.2010.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 05/07/2010] [Accepted: 05/11/2010] [Indexed: 12/27/2022]
Abstract
The endocrine pancreas is central in the physiopathology of diabetes mellitus. Nutrients and hormones control endocrine pancreatic function and the secretion of insulin and other pancreatic islet hormones. Although the pancreas is not usually considered as a target of steroids, increasing evidence indicates that sex steroid hormones modify pancreatic islet function. The biological effects of steroid hormones are transduced by both, classical and non-classical steroid receptors that in turn produce slow genomic and rapid non-genomic responses. In this review, we focused on the effects of sex steroid hormones on endocrine pancreatic function, with special emphasis in animal studies.
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Affiliation(s)
- Sumiko Morimoto
- Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, 14000 México, DF, Mexico
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264
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Vandenput L, Ohlsson C. Sex steroid metabolism in the regulation of bone health in men. J Steroid Biochem Mol Biol 2010; 121:582-8. [PMID: 20362055 DOI: 10.1016/j.jsbmb.2010.03.067] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 03/18/2010] [Accepted: 03/23/2010] [Indexed: 12/11/2022]
Abstract
The growth and maintenance of both the female and the male skeleton are influenced by sex steroids. Although the regulation of the female skeleton by estrogens is well established, the relative importance of androgens and estrogens for the male skeleton remains uncertain. Evidence from cross-sectional and longitudinal studies suggests that serum estradiol levels are more strongly associated with bone mineral density, bone turnover and bone loss than testosterone levels are in adult men. In addition, it appears that a threshold level of serum estradiol exists for optimal skeletal maturation and prevention of both bone loss and fractures. Also, the specificity of the assay technique should be considered when examining serum sex steroid levels in epidemiological cohorts, with a preference for the gold standard mass spectrometry. Additionally, serum levels of sex steroid metabolites, rather than the bio-active sex steroids, may be better markers of local sex steroid action at the target tissue level. In this respect, serum levels of glucuronidated androgen metabolites appear to provide additional information as markers of local androgenic activity in bone than the bio-active androgens. Taken together, even though an important role of testosterone is not excluded, estradiol is an important regulator of bone health in men.
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Affiliation(s)
- Liesbeth Vandenput
- Center for Bone and Arthritis Research at the Sahlgrenska Academy, Department of Internal Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
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265
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Xu XH, Dong SS, Guo Y, Yang TL, Lei SF, Papasian CJ, Zhao M, Deng HW. Molecular genetic studies of gene identification for osteoporosis: the 2009 update. Endocr Rev 2010; 31:447-505. [PMID: 20357209 PMCID: PMC3365849 DOI: 10.1210/er.2009-0032] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 02/02/2010] [Indexed: 12/12/2022]
Abstract
Osteoporosis is a complex human disease that results in increased susceptibility to fragility fractures. It can be phenotypically characterized using several traits, including bone mineral density, bone size, bone strength, and bone turnover markers. The identification of gene variants that contribute to osteoporosis phenotypes, or responses to therapy, can eventually help individualize the prognosis, treatment, and prevention of fractures and their adverse outcomes. Our previously published reviews have comprehensively summarized the progress of molecular genetic studies of gene identification for osteoporosis and have covered the data available to the end of September 2007. This review represents our continuing efforts to summarize the important and representative findings published between October 2007 and November 2009. The topics covered include genetic association and linkage studies in humans, transgenic and knockout mouse models, as well as gene-expression microarray and proteomics studies. Major results are tabulated for comparison and ease of reference. Comments are made on the notable findings and representative studies for their potential influence and implications on our present understanding of the genetics of osteoporosis.
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Affiliation(s)
- Xiang-Hong Xu
- Institute of Molecular Genetics, Xi'an Jiaotong University, Shaanxi, People's Republic of China
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266
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Thomas P, Alyea R, Pang Y, Peyton C, Dong J, Berg AH. Conserved estrogen binding and signaling functions of the G protein-coupled estrogen receptor 1 (GPER) in mammals and fish. Steroids 2010; 75:595-602. [PMID: 19931550 PMCID: PMC2885585 DOI: 10.1016/j.steroids.2009.11.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 11/12/2009] [Indexed: 12/01/2022]
Abstract
Recent studies by several research groups have shown that G protein estrogen receptor-1 (GPER) formerly known as GPR30, mediates 17beta-estradiol (E2) activation of signal transduction pathways in a variety of human cancer cells and displays E2 binding typical of a membrane estrogen receptor. However, the importance of GPER as an estrogen receptor has been questioned by Otto and co-workers. Some of the pitfalls in investigating the functions of recombinant steroid membrane receptors that may explain the negative results of these investigators are discussed. The characteristics of GPER have also been investigated in a teleost fish, Atlantic croaker, where it has been shown to mediate E2 inhibition of oocyte maturation. Investigations on newly discovered homologous proteins from distantly related vertebrate groups are valuable for determining their fundamental, evolutionarily conserved functions. Therefore, the functions of croaker and human GPERs were compared. The comparisons show that croaker and human GPER have very similar estrogen binding characteristics, typical of estrogen membrane receptors, and activate the same estrogen signaling pathways via stimulatory G proteins (Gs) resulting in increased cAMP production. These results suggest that the estrogen binding and estrogen signaling functions of GPER arose early in vertebrate evolution, prior to the divergence of the teleosts from the tetrapods, more than 200 million years ago. The finding that estrogen membrane signaling through GPER has been conserved for such a long period in two distantly related vertebrate groups, mammals and fish, suggests that this is a fundamental function of GPER in vertebrates, and likely its major physiological role.
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Affiliation(s)
- P Thomas
- University of Texas at Austin Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA.
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267
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Langer G, Bader B, Meoli L, Isensee J, Delbeck M, Noppinger PR, Otto C. A critical review of fundamental controversies in the field of GPR30 research. Steroids 2010; 75:603-10. [PMID: 20034504 DOI: 10.1016/j.steroids.2009.12.006] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 11/25/2009] [Accepted: 12/12/2009] [Indexed: 01/01/2023]
Abstract
The female sex hormone estradiol plays an important role in reproduction, mammary gland development, bone turnover, metabolism, and cardiovascular function. The effects of estradiol are mediated by two classical nuclear receptors, estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta). In 2005, G-protein-coupled receptor 30 (GPR30) was claimed to act as a non-classical estrogen receptor that was also activated by the ERalpha and ERbeta antagonists tamoxifen and fulvestrant (ICI 182780). Despite many conflicting results regarding the potential role of GPR30 as an estrogen receptor, the official nomenclature was changed to GPER (G-protein-coupled estrogen receptor). This review revisits the inconsistencies that still exist in the literature and focuses on selected publications that basically address the following two questions: what is the evidence for and against the hypothesis that GPR30 acts as an estrogen receptor? What is the potential in vivo role of GPR30? Thus, in the first part we focus on conflicting results from in vitro studies analysing the subcellular localization of GPR30, its ability to bind (or not to bind) estradiol and to signal (or not to signal) in response to estradiol. In the second part, we discuss the strengths and limitations of four available GPR30 mouse models. We elucidate the potential impact of different targeting strategies on phenotypic diversity.
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Affiliation(s)
- Gernot Langer
- Lead Generation & Optimization, Screening Berlin, Bayer Schering Pharma AG, 13342 Berlin, Germany
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268
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Nayak TK, Dennis MK, Ramesh C, Burai R, Atcher RW, Sklar LA, Norenberg JP, Hathaway HJ, Arterburn JB, Prossnitz ER. Influence of charge on cell permeability and tumor imaging of GPR30-targeted 111in-labeled nonsteroidal imaging agents. ACS Chem Biol 2010; 5:681-90. [PMID: 20486699 DOI: 10.1021/cb1000636] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent clinical studies implicate the role of G protein-coupled estrogen receptor, GPR30, in aggressive forms of breast, ovarian, and endometrial cancers. However, the functional role of GPR30 at cellular and molecular levels remains less clear and controversial, particularly its subcellular location. The primary objective of this study was to develop radiolabeled neutral and charged GPR30-targeted nonsteroidal analogues to understand the influence of ligand charge on cell binding, cellular permeability, and in vivo tumor imaging. Therefore, we developed a series of GPR30-targeted (111/113)In(III)-labeled analogues using macrocyclic and acyclic polyamino-polycarboxylate chelate designs that would render either a net negative or neutral charge. In vitro biological evaluations were performed to determine the role of negatively charged analogues on receptor binding and activation using calcium mobilization and phosphoinositide 3-kinase assays. In vivo evaluations were performed on GPR30-expressing human endometrial Hec50 tumor-bearing mice to characterize the biodistribution and potential application of GPR30-targeted imaging agents for translational research. In vitro functional assays revealed an effect of charge, such that only the neutral analogue activated GPR30-mediated rapid signaling pathways. These observations are consistent with expectations for initial rates of membrane permeability and suggest an intracellular rather than the cell surface location of functional receptor. In vivo studies revealed receptor-mediated uptake of the radiotracer in target organs and tumors; however, further structural modifications will be required for the development of future generations of GPR30-targeted imaging agents with enhanced metabolic properties and decreased nonspecific localization to the intestines.
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Affiliation(s)
- Tapan K. Nayak
- Department of Cell Biology and Physiology
- College of Pharmacy
| | | | - Chinnasamy Ramesh
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Ritwik Burai
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Robert W. Atcher
- College of Pharmacy
- UNM Cancer Center
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - Larry A. Sklar
- College of Pharmacy
- UNM Cancer Center
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, New Mexico 87131
| | | | | | - Jeffrey B. Arterburn
- UNM Cancer Center
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
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269
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Fu Z, Zhang W, Zhen W, Lum H, Nadler J, Bassaganya-Riera J, Jia Z, Wang Y, Misra H, Liu D. Genistein induces pancreatic beta-cell proliferation through activation of multiple signaling pathways and prevents insulin-deficient diabetes in mice. Endocrinology 2010; 151:3026-37. [PMID: 20484465 PMCID: PMC2903942 DOI: 10.1210/en.2009-1294] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Genistein, a flavonoid in legumes and some herbal medicines, has various biological actions. However, studies on whether genistein has an effect on pancreatic beta-cell function are very limited. In the present study, we investigated the effect of genistein on beta-cell proliferation and cellular signaling related to this effect and further determined its antidiabetic potential in insulin-deficient diabetic mice. Genistein induced both INS1 and human islet beta-cell proliferation after 24 h of incubation, with 5 mum genistein inducing a maximal 27% increase. The effect of genistein on beta-cell proliferation was neither dependent on estrogen receptors nor shared by 17beta-estradiol or a host of structurally related flavonoid compounds. Pharmacological or molecular intervention of protein kinase A (PKA) or ERK1/2 completely abolished genistein-stimulated beta-cell proliferation, suggesting that both molecules are essential for genistein action. Consistent with its effect on cell proliferation, genistein induced cAMP/PKA signaling and subsequent phosphorylation of ERK1/2 in both INS1 cells and human islets. Furthermore, genistein induced protein expression of cyclin D1, a major cell-cycle regulator essential for beta-cell growth. Dietary intake of genistein significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in streptozotocin-induced diabetic mice, concomitant with improved islet beta-cell proliferation, survival, and mass. These results demonstrate that genistein may be a natural antidiabetic agent by directly modulating pancreatic beta-cell function via activation of the cAMP/PKA-dependent ERK1/2 signaling pathway.
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Affiliation(s)
- Zhuo Fu
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
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270
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Pérez-López FR, Larrad-Mur L, Kallen A, Chedraui P, Taylor HS. Gender differences in cardiovascular disease: hormonal and biochemical influences. Reprod Sci 2010; 17:511-31. [PMID: 20460551 PMCID: PMC3107852 DOI: 10.1177/1933719110367829] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Atherosclerosis is a complex process characterized by an increase in vascular wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. There is evidence that females are at lower risk of developing cardiovascular disease (CVD) as compared to males. This has led to an interest in examining the contribution of genetic background and sex hormones to the development of CVD. The objective of this review is to provide an overview of factors, including those related to gender, that influence CVD. METHODS Evidence analysis from PubMed and individual searches concerning biochemical and endocrine influences and gender differences, which affect the origin and development of CVD. RESULTS Although still controversial, evidence suggests that hormones including estradiol and androgens are responsible for subtle cardiovascular changes long before the development of overt atherosclerosis. CONCLUSION Exposure to sex hormones throughout an individual's lifespan modulates many endocrine factors involved in atherosclerosis.
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Affiliation(s)
- Faustino R Pérez-López
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Zaragoza, Clínico de Zaragoza Hospital, Zaragoza, Spain
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271
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Kolkova Z, Noskova V, Ehinger A, Hansson S, Casslen B. G protein-coupled estrogen receptor 1 (GPER, GPR 30) in normal human endometrium and early pregnancy decidua. Mol Hum Reprod 2010; 16:743-51. [DOI: 10.1093/molehr/gaq043] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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272
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Balhuizen A, Kumar R, Amisten S, Lundquist I, Salehi A. Activation of G protein-coupled receptor 30 modulates hormone secretion and counteracts cytokine-induced apoptosis in pancreatic islets of female mice. Mol Cell Endocrinol 2010; 320:16-24. [PMID: 20122988 DOI: 10.1016/j.mce.2010.01.030] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 01/21/2010] [Accepted: 01/21/2010] [Indexed: 12/22/2022]
Abstract
The role of the newly discovered estrogen receptor GPR30 in islet physiology and pathophysiology is unclear. We examined GPR30 expression in relation to hormone secretion and possible anti-apoptotic effects in isolated mouse islets using the synthetic GPR30 ligand G-1. The mRNA and protein expression of GPR30 was analyzed by qPCR, Western blot and confocal microscopy. Hormone secretion and cAMP content were determined with RIA and apoptosis in islet cells with the Annexin-V method. GPR30 mRNA and protein expression was markedly higher in islets from females compared to male. This gender difference was not found for the genomic estrogen receptors ER alpha and ER beta, the ER alpha expression being 10-fold higher than ER beta in both genders. Confocal microscopy revealed abounden GPR30 expression in insulin, glucagon and somatostatin cells. Dose-response studies of G-1 vs 17beta-estradiol in isolated islets at 1 or 12 mM glucose showed an almost identical pattern in that both compounds increased insulin and inhibited glucagon and somatostatin secretion. ICI-182,780 and EM-652, potent antagonists of the 17beta-estradiol receptors (ER alpha and ER beta) did not influence the amplifying effect of G-1 or 17beta-estradiol on cAMP content or insulin secretion from isolated islets. Cytokine-induced (IL-1 beta+TNFalpha+INF gamma) apoptosis in islets, cultured for 24h at 5mM glucose, was almost abolished by G-1 or 17beta-estradiol treatment. Addition of ICI-182,780 or EM-652 did not affect this beneficial effect of G-1 or 17beta-estradiol. Taken together, our findings show that GPR30 is expressed in most islet endocrine cells. The synthetic GPR30 ligand G-1 mimics the non-genomic effects of 17beta-estradiol on islet hormone secretion, cAMP content in islets and its anti-apoptotic effects. G-1 or analogs thereof might be new potential candidates in the therapeutic strategy for type 2 diabetes in women.
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Affiliation(s)
- Alexander Balhuizen
- Department of Clinical Science, Islet Cell Physiology, University of Lund, Sweden
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273
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Abstract
The prevalence of diabetes is lower in premenopausal women, especially diabetic syndromes with insulin deficiency, suggesting that the female hormone 17beta-estradiol protects pancreatic beta-cell function. In classical rodent models of beta-cell failure, 17beta-estradiol at physiological concentrations protects pancreatic beta-cells against lipotoxicity, oxidative stress, and apoptosis. In this review, we integrate evidence showing that estrogens and their receptors have direct effects on islet biology. The estrogen receptor (ER)-alpha, ER beta, and the G-protein coupled ER are present in beta-cells and enhance islet survival. They also improve islet lipid homeostasis and insulin biosynthesis. We also discuss evidence that ERs modulate insulin sensitivity and energy homeostasis, which indirectly alter beta-cell biology in diabetic and obese conditions.
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Affiliation(s)
- Suhuan Liu
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University, Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, Illinois 60611, USA
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274
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Affiliation(s)
- Ross D Feldman
- Department of Medicine, University of Western Ontario, London, Ontario, Canada.
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275
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Vico L, Vanacker JM. Sex hormones and their receptors in bone homeostasis: insights from genetically modified mouse models. Osteoporos Int 2010; 21:365-72. [PMID: 19495826 DOI: 10.1007/s00198-009-0963-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 04/29/2009] [Indexed: 10/20/2022]
Abstract
In this review, we summarize available data regarding bone phenotypes in estrogen receptors alpha and beta, androgen receptor, and aromatase enzyme-deficient mice. We examine sex differences in the trabecular and cortical bone compartments and we discuss these findings in relation to known estrogen effects in humans. We also report how estrogen influences the responsiveness of the skeleton to exercise. Although uncertainties remain, it is clear that both estrogen and androgen are important for both male and female skeleton. Estrogen receptor alpha mainly through its classical signaling pathway is particularly important for the male mice skeleton while both estrogen receptors alpha and beta are required for female mice skeleton. These deletions also induce major hormonal alterations themselves impacting on bone metabolism. More investigations are needed to fully understand the respective role of all these receptors in periosteal expansion in both sexes and the way they affect the mechanical sensitivity of the periosteum.
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Affiliation(s)
- L Vico
- Université de Lyon, INSERM, U890, Université Jean Monnet, St-Etienne, 42023, France.
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276
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Smith EP, Specker B, Korach KS. Recent experimental and clinical findings in the skeleton associated with loss of estrogen hormone or estrogen receptor activity. J Steroid Biochem Mol Biol 2010; 118:264-72. [PMID: 19900547 PMCID: PMC4782142 DOI: 10.1016/j.jsbmb.2009.10.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/25/2009] [Accepted: 10/30/2009] [Indexed: 10/20/2022]
Abstract
Studies on rodent models and rare human disorders of estrogen production or response have revealed an increased complexity of the actions of estrogen on bone. ERalpha disruption in human males results in delayed epiphyseal maturation, tall stature, trabecular thinning, marked cortical thinning, genu valgum and significantly reduced cortical vBMD, but trabecular number is preserved and there is normal to increased periosteal expansion. Aromatase deficiency results overall in a similar phenotype, although less is known about skeletal architecture. Importantly, estrogen replacement in these individuals, even if provided late in the third decade, may normalize aBMD. Less certain is whether there is complete recovery of normal skeletal architecture and strength. Rodent models, in general, are consistent with the human phenotype but are confounded by inherent differences between mouse and human physiology and issues regarding the completeness of the different knock-out lines. Both human and rodent studies suggest that residual effects of estrogen through ERbeta, truncated ERalpha forms or nonclassical estrogen receptors might account for different phenotypes in the hERKO man, aromatase deficient subjects and rodents. Importantly, androgen, particularly by preserving trabecular number and augmenting both periosteal and epiphyseal growth, also has significant actions on bone.
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Affiliation(s)
- Eric P Smith
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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277
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Emerging role of estrogen in the control of cardiometabolic disease. Trends Pharmacol Sci 2010; 31:183-9. [PMID: 20138672 DOI: 10.1016/j.tips.2010.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 01/04/2010] [Accepted: 01/15/2010] [Indexed: 01/24/2023]
Abstract
Menopause is associated with an increased risk of cardiovascular and metabolic disease that is partly independent of aging. This increased risk is largely due to postmenopausal estrogen loss. Estrogen improves insulin sensitivity and ss-cell function. This is consistent with the increased risk of diabetes after menopause and the finding that menopausal hormone therapy (MHT) lowers the incidence of diabetes. Experimental data suggest that estrogen has anti-atherosclerotic and pro-thrombotic properties. This is consistent with observational and interventional studies suggesting that MHT reduces the risk of cardiovascular disease if initiated early in women with a low-risk profile, but might increase risk in older women and/or those with other risk factors (e.g. dyslipidemia). Future research focusing on improving prevention of cardiometabolic disease through MHT may help to identify agents with higher tissue- and estrogen receptor-isoform specificity than currently used hormones.
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278
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Ariazi EA, Brailoiu E, Yerrum S, Shupp HA, Slifker MJ, Cunliffe HE, Black MA, Donato AL, Arterburn JB, Oprea TI, Prossnitz ER, Dun NJ, Jordan VC. The G protein-coupled receptor GPR30 inhibits proliferation of estrogen receptor-positive breast cancer cells. Cancer Res 2010; 70:1184-94. [PMID: 20086172 DOI: 10.1158/0008-5472.can-09-3068] [Citation(s) in RCA: 187] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The G protein-coupled receptor GPR30 binds 17beta-estradiol (E(2)) yet differs from classic estrogen receptors (ERalpha and ERbeta). GPR30 can mediate E(2)-induced nongenomic signaling, but its role in ERalpha-positive breast cancer remains unclear. Gene expression microarray data from five cohorts comprising 1,250 breast carcinomas showed an association between increased GPR30 expression and ERalpha-positive status. We therefore examined GPR30 in estrogenic activities in ER-positive MCF-7 breast cancer cells using G-1 and diethylstilbestrol (DES), ligands that selectively activate GPR30 and ER, respectively, and small interfering RNAs. In expression studies, E(2) and DES, but not G-1, transiently downregulated both ER and GPR30, indicating that this was ER mediated. In Ca(2+) mobilization studies, GPR30, but not ERalpha, mediated E(2)-induced Ca(2+) responses because E(2), 4-hydroxytamoxifen (activates GPR30), and G-1, but not DES, elicited cytosolic Ca(2+) increases not only in MCF-7 cells but also in ER-negative SKBr3 cells. Additionally, in MCF-7 cells, GPR30 depletion blocked E(2)-induced and G-1-induced Ca(2+) mobilization, but ERalpha depletion did not. Interestingly, GPR30-coupled Ca(2+) responses were sustained and inositol triphosphate receptor mediated in ER-positive MCF-7 cells but transitory and ryanodine receptor mediated in ER-negative SKBr3 cells. Proliferation studies involving GPR30 depletion indicated that the role of GPR30 was to promote SKBr3 cell growth but reduce MCF-7 cell growth. Supporting this, G-1 profoundly inhibited MCF-7 cell growth, potentially via p53 and p21 induction. Further, flow cytometry showed that G-1 blocked MCF-7 cell cycle progression at the G(1) phase. Thus, GPR30 antagonizes growth of ERalpha-positive breast cancer and may represent a new target to combat this disease.
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Affiliation(s)
- Eric A Ariazi
- Fox Chase Cancer Center; Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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279
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Broughton BRS, Miller AA, Sobey CG. Endothelium-dependent relaxation by G protein-coupled receptor 30 agonists in rat carotid arteries. Am J Physiol Heart Circ Physiol 2010; 298:H1055-61. [PMID: 20061543 DOI: 10.1152/ajpheart.00878.2009] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have identified that the novel membrane estrogen receptor, G protein-coupled receptor 30 (GPR30), is present in blood vessels. However, the signaling mechanisms associated with GPR30 in the vasculature remain unclear. We examined whether putative agonists of GPR30 exert vasorelaxant and/or antioxidant effects similar to those reported for estrogen. Using wire myography, we assessed the role of the endothelium in relaxation responses to the GPR30 agonists, G-1 and 5408-0877 (1 nM-10 microM), in U-46619-precontracted common carotid arteries from Sprague-Dawley rats. Furthermore, using lucigenin (5 microM)-enhanced chemiluminescence, we tested the effect of G-1 (10 microM) on superoxide levels. Specific immunofluorescence was also used to confirm GPR30 expression in the arterial wall. We found that G-1 and 5408-0877 induced a concentration-dependent relaxation in carotid arteries from both male and female rats. Interestingly, G-1- and 5408-0877-induced relaxation was abolished by endothelium removal and abrogated in the presence of the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (100 microM). In addition, G-1 significantly decreased NADPH (100 microM)-stimulated superoxide production by carotid and intracranial (pooled basilar and middle cerebral) arteries but also attenuated the superoxide signal detected in a cell-free xanthine/xanthine oxidase assay. Furthermore, GPR30 immunoreactivity was observed in endothelial and vascular smooth muscle cells of carotid arteries from both genders. These findings indicate that GPR30 is expressed throughout the arterial wall and that GPR30 agonists elicit endothelial-derived nitric oxide-dependent relaxation of the carotid artery in male and female rats. Additionally, G-1 appears to directly scavenge superoxide anion.
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280
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Mizukami Y. In vivo functions of GPR30/GPER-1, a membrane receptor for estrogen: from discovery to functions in vivo. Endocr J 2010; 57:101-7. [PMID: 19996532 DOI: 10.1507/endocrj.k09e-332] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptor 30/G protein-coupled estrogen receptor-1 (GPR30/GPER-1) was reported as a novel membrane receptor for estrogen in 2005. However, the research on GPR30 has produced conflicting reports with regard to its intracellular localization, the tissue distribution of its expression, and some its functions. Recently, in addition to the finding of G-1, a GPR30 agonist, GPR30 KO mice have been produced in laboratories, and this has significantly increased the confidence in the data. In this review, the intrinsic appearance of GPR30 is approached based mainly on data obtained in vivo.
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Affiliation(s)
- Yoichi Mizukami
- The Center for Gene Research, Yamaguchi University, 1-1-1 Minami-Kogushi, Ube,Yamaguchi, Japan.
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281
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Abstract
The gonadal steroid, 17beta-estradiol (E(2)), acts as a protective hormone preventing beta-cell apoptosis in vivo in mice of both sexes and in cultured mouse and human islets. E(2) signals via the classical estrogen receptor (ER)alpha and ERbeta, an extranuclear form of ERalpha and the G protein-coupled estrogen receptor (GPER). In a recent study, we determined the contribution of these receptors to beta-cell survival, using a combination of genetic and pharmacological tools in mice and cultured mouse and human islets. We showed that E(2) favors islet survival by preventing apoptosis via ERalpha and ERbeta through ERE-independent, extra-nuclear mechanisms and with a predominant ERalpha effect. We also revealed that E(2) prevents apoptosis via GPER-dependent mechanisms. Here, we show that E(2) prevents apoptosis independently of gene transcription or de novo protein synthesis suggesting that E(2) cytoprotection happens independently of nuclear events. Furthermore, we report that E(2) islet cytoprotection can be mimicked by the nonfeminizing E(2) stereoisomer, 17alpha-estradiol, suggesting that it is partially non-estrogen receptor mediated. These studies identify novel estrogen pathways and targets to protect islet survival.
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Affiliation(s)
- Suhuan Liu
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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282
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Soriano S, Ropero AB, Alonso-Magdalena P, Ripoll C, Quesada I, Gassner B, Kuhn M, Gustafsson JA, Nadal A. Rapid regulation of K(ATP) channel activity by 17{beta}-estradiol in pancreatic {beta}-cells involves the estrogen receptor {beta} and the atrial natriuretic peptide receptor. Mol Endocrinol 2009; 23:1973-82. [PMID: 19855088 DOI: 10.1210/me.2009-0287] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The ATP-sensitive potassium (K(ATP)) channel is a key molecule involved in glucose-stimulated insulin secretion. The activity of this channel regulates beta-cell membrane potential, glucose- induced [Ca(2+)](i) signals, and insulin release. In this study, the rapid effect of physiological concentrations of 17beta-estradiol (E2) on K(ATP) channel activity was studied in intact beta-cells by use of the patch-clamp technique. When cells from wild-type (WT) mice were used, 1 nm E2 rapidly reduced K(ATP) channel activity by 60%. The action of E2 on K(ATP) channel was not modified in beta-cells from ERalpha-/- mice, yet it was significantly reduced in cells from ERbeta-/- mice. The effect of E2 was mimicked by the ERbeta agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN). Activation of ERbeta by DPN enhanced glucose-induced Ca(2+) signals and insulin release. Previous evidence indicated that the acute inhibitory effects of E2 on K(ATP) channel activity involve cyclic GMP and cyclic GMP-dependent protein kinase. In this study, we used beta-cells from mice with genetic ablation of the membrane guanylate cyclase A receptor for atrial natriuretic peptide (also called the atrial natriuretic peptide receptor) (GC-A KO mice) to demonstrate the involvement of this membrane receptor in the rapid E2 actions triggered in beta-cells. E2 rapidly inhibited K(ATP) channel activity and enhanced insulin release in islets from WT mice but not in islets from GC-A KO mice. In addition, DPN reduced K(ATP) channel activity in beta-cells from WT mice, but not in beta-cells from GC-A KO mice. This work unveils a new role for ERbeta as an insulinotropic molecule that may have important physiological and pharmacological implications.
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Affiliation(s)
- Sergi Soriano
- Institute of Bioengineering and CIBERDEM, Universidad Miguel Hernández de Elche, Alicante, Spain
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283
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Liu S, Le May C, Wong WP, Ward RD, Clegg DJ, Marcelli M, Korach KS, Mauvais-Jarvis F. Importance of extranuclear estrogen receptor-alpha and membrane G protein-coupled estrogen receptor in pancreatic islet survival. Diabetes 2009; 58:2292-302. [PMID: 19587358 PMCID: PMC2750222 DOI: 10.2337/db09-0257] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 06/26/2009] [Indexed: 01/08/2023]
Abstract
OBJECTIVE We showed that 17beta-estradiol (E(2)) favors pancreatic beta-cell survival via the estrogen receptor-alpha (ERalpha) in mice. E(2) activates nuclear estrogen receptors via an estrogen response element (ERE). E(2) also activates nongenomic signals via an extranuclear form of ERalpha and the G protein-coupled estrogen receptor (GPER). We studied the contribution of estrogen receptors to islet survival. RESEARCH DESIGN AND METHODS We used mice and islets deficient in estrogen receptor-alpha (alphaERKO(-/-)), estrogen receptor-beta (betaERKO(-/-)), estrogen receptor-alpha and estrogen receptor-beta (alphabetaERKO(-/-)), and GPER (GPERKO(-/-)); a mouse lacking ERalpha binding to the ERE; and human islets. These mice and islets were studied in combination with receptor-specific pharmacological probes. RESULTS We show that ERalpha protection of islet survival is ERE independent and that E(2) favors islet survival through extranuclear and membrane estrogen receptor signaling. We show that ERbeta plays a minor cytoprotective role compared to ERalpha. Accordingly, betaERKO(-/-) mice are mildly predisposed to streptozotocin-induced islet apoptosis. However, combined elimination of ERalpha and ERbeta in mice does not synergize to provoke islet apoptosis. In alphabetaERKO(-/-) mice and their islets, E(2) partially prevents apoptosis suggesting that an alternative pathway compensates for ERalpha/ERbeta deficiency. We find that E(2) protection of islet survival is reproduced by a membrane-impermeant E(2) formulation and a selective GPER agonist. Accordingly, GPERKO(-/-) mice are susceptible to streptozotocin-induced insulin deficiency. CONCLUSIONS E(2) protects beta-cell survival through ERalpha and ERbeta via ERE-independent, extra-nuclear mechanisms, as well as GPER-dependent mechanisms. The present study adds a novel dimension to estrogen biology in beta-cells and identifies GPER as a target to protect islet survival.
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Affiliation(s)
- Suhuan Liu
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University School of Medicine, Chicago, Illinois
| | - Cedric Le May
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University School of Medicine, Chicago, Illinois
| | - Winifred P.S. Wong
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University School of Medicine, Chicago, Illinois
| | - Robert D. Ward
- Department of Medicine, Division of Diabetes, Endocrinology & Metabolism, Baylor College of Medicine, Houston, Texas
| | - Deborah J. Clegg
- Department of Internal Medicine, Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Marco Marcelli
- Department of Medicine, Division of Diabetes, Endocrinology & Metabolism, Baylor College of Medicine, Houston, Texas
| | - Kenneth S. Korach
- National Institutes of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Franck Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University School of Medicine, Chicago, Illinois
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284
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Olde B, Leeb-Lundberg LMF. GPR30/GPER1: searching for a role in estrogen physiology. Trends Endocrinol Metab 2009; 20:409-16. [PMID: 19734054 DOI: 10.1016/j.tem.2009.04.006] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/17/2009] [Accepted: 04/21/2009] [Indexed: 12/24/2022]
Abstract
Estrogens are sex hormones that are central to health and disease in both genders. These hormones have long been recognized to act in complex ways, both through relatively slow genomic mechanisms and via fast non-genomic mechanisms. Several recent in vitro studies suggest that GPR30, or G protein-coupled estrogen receptor 1 (GPER1), is a functional membrane estrogen receptor involved in non-genomic estrogen signaling. However, this function is not universally accepted. Studies concerning the role of GPER1 in vivo are now beginning to appear but with divergent results. In this review we discuss current knowledge on the physiological role of GPER1 in the nervous system as well as in reproduction, metabolism, bone, and in the cardiovascular and immune systems.
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Affiliation(s)
- Björn Olde
- Unit of Drug Target Discovery, Department of Experimental Medical Science, Lund University, SE-22184 Lund, Sweden
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285
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Meyer MR, Haas E, Prossnitz ER, Barton M. Non-genomic regulation of vascular cell function and growth by estrogen. Mol Cell Endocrinol 2009; 308:9-16. [PMID: 19549587 PMCID: PMC2780565 DOI: 10.1016/j.mce.2009.03.009] [Citation(s) in RCA: 81] [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: 10/29/2008] [Revised: 02/22/2009] [Accepted: 03/05/2009] [Indexed: 12/21/2022]
Abstract
Estrogens exert rapid, non-genomic effects, which are mediated by plasma membrane-associated estrogen receptors (mER) mERalpha and mERbeta, and the intracellular transmembrane G protein-coupled estrogen receptor (GPER). Membrane-initiated responses contribute to transcriptional activation, resulting in a complex interplay of nuclear and extra-nuclear mechanisms that mediate the acute physiological responses to estrogens. Non-genomic estrogen signaling also activates a variety of intracellular estrogen signaling pathways that regulate vascular function and cell growth involving rapid but also long-term effects. This review discusses recent advances in understanding of the mechanisms of non-genomic estrogen receptor signaling in the vascular wall.
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Affiliation(s)
- Matthias R. Meyer
- Departement für Innere Medizin, Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Switzerland
| | - Elvira Haas
- Departement für Innere Medizin, Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Switzerland
| | - Eric R. Prossnitz
- Department of Cell Biology and Physiology, Cancer Research and Treatment Center, University of New Mexico Health Sciences Center, Albuquerque, NM 87120, United States
| | - Matthias Barton
- Departement für Innere Medizin, Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Switzerland
- Molecular Internal Medicine, University of Zurich, 8057 Zurich
- Corresponding author: Matthias Barton, M.D., Professor and Head, Molecular Internal Medicine, University of Zurich, LTK Y44 G22, Winterthurer Strasse 190, 8057 Zurich, Switzerland. Tel. +41-44-635 5451 Fax +41-44-635 6875,
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286
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Prossnitz ER, Maggiolini M. Mechanisms of estrogen signaling and gene expression via GPR30. Mol Cell Endocrinol 2009; 308:32-8. [PMID: 19464786 PMCID: PMC2847286 DOI: 10.1016/j.mce.2009.03.026] [Citation(s) in RCA: 279] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 03/09/2009] [Accepted: 03/09/2009] [Indexed: 12/18/2022]
Abstract
The effects of estrogen are widespread throughout the body. Although the classical nuclear estrogen receptors have been known for many years to decades and their primary modes of action as transcriptional regulators is well understood, certain aspects of estrogen biology remain inconsistent with the mechanisms of action of these receptor. More recently, the G protein-coupled receptor, GPR30/GPER, has been suggested to contribute to some of the cellular and physiological effects of estrogen. Not only does GPR30 mediate some of the rapid signal transduction events following cell stimulation, such as calcium mobilization and kinase activation, it also appears to regulate rapid transcriptional activation of genes such as c-fos. Since many cells and tissues co-express classical estrogen receptors and GPR30, there exists great diversity in the possible avenues of synergism and antagonism. In this review, we will provide an overview of GPR30 function, focusing on the rapid signaling events that culminate in the transcriptional activation of certain genes.
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Affiliation(s)
- Eric R Prossnitz
- Department of Cell Biology & Physiology and Cancer Research and Treatment Center, University of New Mexico, Albuquerque, NM 87131, USA.
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287
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Qiao GF, Li BY, Lu YJ, Fu YL, Schild JH. 17Beta-estradiol restores excitability of a sexually dimorphic subset of myelinated vagal afferents in ovariectomized rats. Am J Physiol Cell Physiol 2009; 297:C654-64. [PMID: 19570896 PMCID: PMC2740394 DOI: 10.1152/ajpcell.00059.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 06/22/2009] [Indexed: 12/20/2022]
Abstract
We recently identified a myelinated vagal afferent subpopulation (Ah type) far more prevalent in female than male rats and showed that this difference extends to functionally specific visceral sensory afferents, baroreceptors of the aortic arch. Excitability of myelinated Ah-type afferents is markedly reduced after ovariectomy (OVX). Here we tested the hypothesis that 17beta-estradiol can selectively restore excitability of these sex-specific vagal afferents. Acutely isolated vagal afferent neurons (VGN) from intact and OVX adult female rats were used with patch-clamp technique and current-clamp protocols to assess the effect of acute application of 17beta-estradiol on neuronal excitability. At over physiologically relevant 17beta-estradiol concentrations for rat (1-10 nM) excitability of myelinated Ah-type vagal afferents is restored to discharge frequencies comparable to those in intact females, albeit with some interesting differences related to burst and sustained patterns of neuronal discharge. Restoration of excitability occurs within 3 min of hormone application and is stereo specific, because 1,000 nM 17alpha-estradiol fails to alter excitability. Furthermore, activation of G protein-coupled estrogen receptor GPR30 with highly selective agonist G-1 similarly restores excitability of Ah-type afferents. The effectiveness of 17beta-estradiol and G-1 is completely eliminated by application of high-affinity estrogen receptor ligand ICI-182,780. 17beta-Estradiol conjugated with BSA is approximately 70% as effective as 17beta-estradiol alone in restoring Ah-type VGN excitability. These data support our conclusions that the cellular mechanisms leading to rapid restoration of neuronal excitability of myelinated Ah-type VGN after OVX occur, at least in part, via membrane-bound estrogen receptors. We contend that recovery of high-frequency discharge at physiologically relevant 17beta-estradiol concentrations implies that this unique subtype of low-threshold myelinated vagal afferent may account for some of the sex-related differences in visceral organ system function. Sex differences in cardiovascular and gastrointestinal function and the potential role of GPR30 in modulation of sex-specific myelinated Ah-type vagal afferents are discussed.
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Affiliation(s)
- Guo-Fen Qiao
- Department of Biomedical Devices and Engineering, School of Life Science, Harbin Technological University, Harbin, China
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288
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Nadal A, Alonso-Magdalena P, Soriano S, Ropero AB, Quesada I. The role of oestrogens in the adaptation of islets to insulin resistance. J Physiol 2009; 587:5031-7. [PMID: 19687125 DOI: 10.1113/jphysiol.2009.177188] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Pregnancy is characterized by peripheral insulin resistance, which is developed in parallel with a plasma increase of maternal hormones; these include prolactin, placental lactogens, progesterone and oestradiol among others. Maternal insulin resistance is counteracted by the adaptation of the islets of Langerhans to the higher insulin demand. If this adjustment is not produced, gestational diabetes may be developed. The adaptation process of islets is characterized by an increase of insulin biosynthesis, an enhanced glucose-stimulated insulin secretion (GSIS) and an increase of beta-cell mass. It is not completely understood why, in some individuals, beta-cell mass and function fail to adapt to the metabolic demands of pregnancy, yet a disruption of the beta-cell response to maternal hormones may play a key part. The role of the maternal hormone 17beta-oestradiol (E2) in this adaptation process has been largely unknown. However, in recent years, it has been demonstrated that E2 acts directly on beta-cells to increase insulin biosynthesis and to enhance GSIS through different molecular mechanisms. E2 does not increase beta-cell proliferation but it is involved in beta-cell survival. Classical oestrogen receptors ERalpha and ERbeta, as well as the G protein-coupled oestrogen receptor (GPER) seem to be involved in these adaptation changes. In addition, as the main production of E2 in post-menopausal women comes from the adipose tissue, E2 may act as a messenger between adipocytes and islets in obesity.
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Affiliation(s)
- Angel Nadal
- Instituto de Bioingeniería and CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Universidad Miguel Hernández de Elche, 03202 Elche, Alicante, Spain.
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289
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Hazell GGJ, Yao ST, Roper JA, Prossnitz ER, O'Carroll AM, Lolait SJ. Localisation of GPR30, a novel G protein-coupled oestrogen receptor, suggests multiple functions in rodent brain and peripheral tissues. J Endocrinol 2009; 202:223-36. [PMID: 19420011 PMCID: PMC2710976 DOI: 10.1677/joe-09-0066] [Citation(s) in RCA: 274] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recently, the G protein-coupled receptor GPR30 has been identified as a novel oestrogen receptor (ER). The distribution of the receptor has been thus far mapped only in the rat central nervous system. This study was undertaken to map the distribution of GPR30 in the mouse brain and rodent peripheral tissues. Immunohistochemistry using an antibody against GPR30 revealed high levels of GPR30 immunoreactivity (ir) in the forebrain (e.g. cortex, hypothalamus and hippocampus), specific nuclei of the midbrain (e.g. the pontine nuclei and locus coeruleus) and the trigeminal nuclei and cerebellum Purkinje layer of the hindbrain in the adult mouse brain. In the rat and mouse periphery, GPR30-ir was detected in the anterior, intermediate and neural lobe of the pituitary, adrenal medulla, renal pelvis and ovary. In situ hybridisation histochemistry using GPR30 riboprobes, revealed intense hybridisation signal for GPR30 in the paraventricular nucleus and supraoptic nucleus (SON) of the hypothalamus, anterior and intermediate lobe of the pituitary, adrenal medulla, renal pelvis and ovary of both rat and mouse. Double immunofluorescence revealed GPR30 was present in both oxytocin and vasopressin neurones of the paraventricular nucleus and SON of the rat and mouse brain. The distribution of GPR30 is distinct from the other traditional ERs and offers an additional way in which oestrogen may mediate its effects in numerous brain regions and endocrine systems in the rodent.
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290
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Lindsey SH, Cohen JA, Brosnihan KB, Gallagher PE, Chappell MC. Chronic treatment with the G protein-coupled receptor 30 agonist G-1 decreases blood pressure in ovariectomized mRen2.Lewis rats. Endocrinology 2009; 150:3753-8. [PMID: 19372194 PMCID: PMC2717873 DOI: 10.1210/en.2008-1664] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mRen2.Lewis congenic strain is an estrogen-sensitive model of hypertension whereby estrogen depletion produces a significant and sustained increase in blood pressure. The recent identification of G protein-coupled receptor 30 (GPR30) as a third estrogen receptor isotype prompted us to test the hypothesis that this novel receptor exhibits beneficial cardiovascular actions in the hypertensive female mRen2.Lewis rat. Intact female, ovariectomized female (OVX), and male mRen2.Lewis rats were treated with the selective GPR30 agonist G-1 or vehicle via osmotic minipump for 2 wk. G-1 significantly reduced systolic blood pressure in OVX (178 +/- 7 to 142 +/- 10 mm Hg, P < 0.001, n = 8) but not intact female (144 +/- 3 to 143 +/- 5 mm Hg, P > 0.05, n = 5) or male mRen2.Lewis rats (207 +/- 7 to 192 +/- 5 mm Hg, P > 0.05, n = 7). G-1 did not alter uterine or body weight in OVX, suggesting activation of a receptor distinct from estrogen receptor-alpha and -beta. In isolated aortic rings from OVX, G-1 reduced constriction in response to angiotensin II. Vascular angiotensin-converting enzyme and angiotensin type 1 receptor mRNA were also lower, whereas angiotensin-converting enzyme-2 mRNA was increased. G-1 treatment in OVX was not associated with alterations in either endothelial nitric oxide synthase expression or acetylcholine-induced relaxation. Immunohistochemical staining for GPR30 was evident in both the intima and media of the aorta. We conclude that the novel estrogen receptor GPR30 may contribute to the beneficial cardiovascular actions of estrogen in female mRen2.Lewis rats through regulation of vascular components of the renin-angiotensin system.
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Affiliation(s)
- Sarah Hoffmann Lindsey
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1032, USA.
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291
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New insights into the molecular mechanisms underlying effects of estrogen on cholesterol gallstone formation. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:1037-47. [PMID: 19589396 DOI: 10.1016/j.bbalip.2009.06.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 06/25/2009] [Accepted: 06/25/2009] [Indexed: 02/07/2023]
Abstract
Epidemiological and clinical studies have found that at all ages women are twice as likely as men to form cholesterol gallstones, and this gender difference begins since puberty and continues through the childbearing years, which highlight the importance of female sex hormones. Estrogen is a crucial hormone in human physiology and regulates a multitude of biological processes. The actions of estrogen have traditionally been ascribed to two closely related classical nuclear hormone receptors, estrogen receptor 1 (ESR1) and ESR2. Recent studies have revealed that the increased risk for cholesterol gallstones in women vs. men is related to differences in how the liver metabolizes cholesterol in response to estrogen. A large number of human and animal studies have proposed that estrogen increases the risk of developing cholesterol gallstones by increasing the hepatic secretion of biliary cholesterol, which, in turn, leads to an increase in cholesterol saturation of bile. Furthermore, it has been identified that hepatic ESR1, but not ESR2, plays a major role in cholesterol gallstone formation in mice in response to high doses of 17beta-estradiol. The mechanisms mediating estrogen's action have become more complicated with the recent identification of a novel estrogen receptor, G protein-coupled receptor 30 (GPR30), a member of the seven-transmembrane G protein-coupled receptor superfamily. In this review, we provide an overview of the evidence for the lithogenic actions of estrogen through ESR1 and discuss the cellular and physiological actions of GPR30 in estrogen-dependent processes and the relationship between GPR30 and classical ESR1 on gallstone formation.
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292
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Abstract
The Hedgehog signaling pathway plays a crucial role in development and disease. Its putative origins in an ancient system involved in regulating bacterial lipid transport and homeostasis offers clues about how the pathway might work today.
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Affiliation(s)
- George Hausmann
- Institute of Molecular Biology, Universität Zürich, Zürich, Switzerland
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293
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Abstract
Sex steroids are important for the growth and maintenance of both the female and the male skeleton. However, the relative contribution of androgens versus estrogens in the regulation of the male skeleton is unclear. Experiments using mice with inactivated sex steroid receptors demonstrated that both activation of the estrogen receptor (ER)alpha and activation of the androgen receptor result in a stimulatory effect on both the cortical and trabecular bone mass in males. ERbeta is of no importance for the skeleton in male mice while it modulates the ERalpha-action on bone in female mice. Previous in vitro studies suggest that the membrane G protein-coupled receptor GPR30 also might be a functional ER. Our in vivo analyses of GPR30-inactivated mice revealed no function of GPR30 for estrogen-mediated effects on bone mass but it is required for normal regulation of the growth plate and estrogen-mediated insulin-secretion. Recent clinical evidence suggests that a threshold exists for estrogen effects on bone in men: rates of bone loss and fracture risk seem to be the highest in men with estradiol levels below this threshold. Taken together, even though these findings do not exclude an important role for testosterone in male skeletal homeostasis, it is now well-established that estrogens are important regulators of bone health in men.
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Affiliation(s)
- Claes Ohlsson
- Center for Bone Research, Division of Endocrinology, Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden.
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294
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Prossnitz ER, Barton M. Signaling, physiological functions and clinical relevance of the G protein-coupled estrogen receptor GPER. Prostaglandins Other Lipid Mediat 2009; 89:89-97. [PMID: 19442754 DOI: 10.1016/j.prostaglandins.2009.05.001] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 05/01/2009] [Accepted: 05/03/2009] [Indexed: 12/29/2022]
Abstract
GPR30, now named GPER1 (G protein-coupled estrogen receptor1) or GPER here, was first identified as an orphan 7-transmembrane G protein-coupled receptor by multiple laboratories using either homology cloning or differential expression and subsequently shown to be required for estrogen-mediated signaling in certain cancer cells. The actions of estrogen are extensive in the body and are thought to be mediated predominantly by classical nuclear estrogen receptors that act as transcription factors/regulators. Nevertheless, certain aspects of estrogen function remain incompatible with the generally accepted mechanisms of classical estrogen receptor action. Many recent studies have revealed that GPER contributes to some of the actions of estrogen, including rapid signaling events and rapid transcriptional activation. With the introduction of GPER-selective ligands and GPER knockout mice, the functions of GPER are becoming more clearly defined. In many cases, there appears to be a complex interplay between the two receptor systems, suggesting that estrogen-mediated physiological responses may be mediated by either receptor or a combination of both receptor types, with important medical implications.
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Affiliation(s)
- Eric R Prossnitz
- Department of Cell Biology & Physiology and UNM Cancer Center, University of New Mexico, Albuquerque, NM 87131, USA.
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295
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Mapping of sex hormone receptors and their modulators along the nephron of male and female mice. FEBS Lett 2009; 583:1644-8. [DOI: 10.1016/j.febslet.2009.04.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/16/2009] [Accepted: 04/20/2009] [Indexed: 11/18/2022]
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296
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Wang C, Dehghani B, Li Y, Kaler LJ, Proctor T, Vandenbark AA, Offner H. Membrane estrogen receptor regulates experimental autoimmune encephalomyelitis through up-regulation of programmed death 1. THE JOURNAL OF IMMUNOLOGY 2009; 182:3294-303. [PMID: 19234228 DOI: 10.4049/jimmunol.0803205] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Although estrogens exert a pronounced protective effect on multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), their therapeutic application has been limited by undesirable side effects thought to be mediated primarily through estradiol binding to intracellular estrogen receptor alpha. In this study, we found that signaling through the putative membrane estrogen receptor, G protein-coupled receptor 30 (GPR30), was sufficient to mediate protection against EAE, which was significantly impaired in GPR30 gene-deficient mice. Treatment with G-1, an agonist that selectively activates GPR30 without engagement of the intracellular estrogen receptors, retained the ability of estradiol to protect against clinical and histological EAE without estradiol-associated side effects, deviated cytokine profiles, and enhanced suppressive activity of CD4(+)Foxp3(+) T regulatory cells through a GPR30- and programmed death 1-dependent mechanism. This study is the first to evaluate the protective effect of GPR30 activation on EAE, and provides a strong foundation for the clinical application of GPR30 agonists such as G-1 in multiple sclerosis.
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Affiliation(s)
- Chunhe Wang
- Neuroimmunology Research, Veterans Affairs Medical Center, Portland, OR 97239, USA.
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297
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Affiliation(s)
- Ellis R Levin
- Long Beach Veterans Affairs Medical Center, Medical Service, Long Beach, California 90822, USA.
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298
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Isensee J, Meoli L, Zazzu V, Nabzdyk C, Witt H, Soewarto D, Effertz K, Fuchs H, Gailus-Durner V, Busch D, Adler T, de Angelis MH, Irgang M, Otto C, Noppinger PR. Expression pattern of G protein-coupled receptor 30 in LacZ reporter mice. Endocrinology 2009; 150:1722-30. [PMID: 19095739 DOI: 10.1210/en.2008-1488] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Multiple reports implicated the function of G protein-coupled receptor (GPR)-30 with nongenomic effects of estrogen, suggesting that GPR30 might be a G-protein coupled estrogen receptor. However, the findings are controversial and the expression pattern of GPR30 on a cell type level as well as its function in vivo remains unclear. Therefore, the objective of this study was to identify cell types that express Gpr30 in vivo by analyzing a mutant mouse model that harbors a lacZ reporter (Gpr30-lacZ) in the Gpr30 locus leading to a partial deletion of the Gpr30 coding sequence. Using this strategy, we identified the following cell types expressing Gpr30: 1) an endothelial cell subpopulation in small arterial vessels of multiple tissues, 2) smooth muscle cells and pericytes in the brain, 3) gastric chief cells in the stomach, 4) neuronal subpopulations in the cortex as well as the polymorph layer of the dentate gyrus, 5) cell populations in the intermediate and anterior lobe of the pituitary gland, and 6) in the medulla of the adrenal gland. In further experiments, we aimed to decipher the function of Gpr30 by analyzing the phenotype of Gpr30-lacZ mice. The body weight as well as fat mass was unchanged in Gpr30-lacZ mice, even if fed with a high-fat diet. Flow cytometric analysis revealed lower frequencies of T cells in both sexes of Gpr30-lacZ mice. Within the T-cell cluster, the amount of CD62L-expressing cells was clearly reduced, suggesting an impaired production of T cells in the thymus of Gpr30-lacZ mice.
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Affiliation(s)
- Jörg Isensee
- Center for Cardiovascular Research, Charité Universitätsmedizin Berlin, Berlin, Germany
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Windahl SH, Andersson N, Chagin AS, Mårtensson UEA, Carlsten H, Olde B, Swanson C, Movérare-Skrtic S, Sävendahl L, Lagerquist MK, Leeb-Lundberg LMF, Ohlsson C. The role of the G protein-coupled receptor GPR30 in the effects of estrogen in ovariectomized mice. Am J Physiol Endocrinol Metab 2009; 296:E490-6. [PMID: 19088255 DOI: 10.1152/ajpendo.90691.2008] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In vitro studies suggest that the membrane G protein-coupled receptor GPR30 is a functional estrogen receptor (ER). The aim of the present study was to determine the possible in vivo role of GPR30 as a functional ER primarily for the regulation of skeletal parameters, including bone mass and longitudinal bone growth, but also for some other well-known estrogen-regulated parameters, including uterine weight, thymus weight, and fat mass. Three-month-old ovariectomized (OVX) GPR30-deficient mice (GPR30(-/-)) and wild-type (WT) mice were treated with either vehicle or increasing doses of estradiol (E(2); 0, 30, 70, 160, or 830 ng.mouse(-1).day(-1)). Body composition [bone mineral density (BMD), fat mass, and lean mass] was analyzed by dual-energy-X ray absorptiometry, while the cortical and trabecular bone compartments were analyzed by peripheral quantitative computerized tomography. Quantitative histological analyses were performed in the distal femur growth plate. Bone marrow cellularity and distribution were analyzed using a fluorescence-activated cell sorter. The estrogenic responses on most of the investigated parameters, including increase in bone mass (total body BMD, spine BMD, trabecular BMD, and cortical bone thickness), increase in uterine weight, thymic atrophy, fat mass reduction, and increase in bone marrow cellularity, were similar for all of the investigated E(2) doses in WT and GPR30(-/-) mice. On the other hand, E(2) treatment reduced longitudinal bone growth, reflected by decreased femur length and distal femur growth plate height, in the WT mice but not in the GPR30(-/-) mice compared with vehicle-treated mice. These in vivo findings demonstrate that GPR30 is not required for normal estrogenic responses on several major well-known estrogen-regulated parameters. In contrast, GPR30 is required for a normal estrogenic response in the growth plate.
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Affiliation(s)
- S H Windahl
- Institute of Medicine, Sahlgrenska Academy, Göteborg University, Göteborg
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300
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Haas E, Bhattacharya I, Brailoiu E, Damjanović M, Brailoiu GC, Gao X, Mueller-Guerre L, Marjon NA, Gut A, Minotti R, Meyer MR, Amann K, Ammann E, Perez-Dominguez A, Genoni M, Clegg DJ, Dun NJ, Resta TC, Prossnitz ER, Barton M. Regulatory role of G protein-coupled estrogen receptor for vascular function and obesity. Circ Res 2009; 104:288-91. [PMID: 19179659 DOI: 10.1161/circresaha.108.190892] [Citation(s) in RCA: 283] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We found that the selective stimulation of the intracellular, transmembrane G protein-coupled estrogen receptor (GPER), also known as GPR30, acutely lowers blood pressure after infusion in normotensive rats and dilates both rodent and human arterial blood vessels. Stimulation of GPER blocks vasoconstrictor-induced changes in intracellular calcium concentrations and vascular tone, as well as serum-stimulated cell proliferation of human vascular smooth muscle cells. Deletion of the GPER gene in mice abrogates vascular effects of GPER activation and is associated with visceral obesity. These findings suggest novel roles for GPER in protecting from cardiovascular disease and obesity.
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Affiliation(s)
- Elvira Haas
- Departement für Innere Medizin, Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Rämistrasse 100, CH-8091 Zürich, Switzerland
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