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Estrogen as a key regulator of energy homeostasis and metabolic health. Biomed Pharmacother 2022; 156:113808. [DOI: 10.1016/j.biopha.2022.113808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/02/2022] [Accepted: 10/03/2022] [Indexed: 11/23/2022] Open
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Taxier LR, Gross KS, Frick KM. Oestradiol as a neuromodulator of learning and memory. Nat Rev Neurosci 2020; 21:535-550. [PMID: 32879508 PMCID: PMC8302223 DOI: 10.1038/s41583-020-0362-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2020] [Indexed: 12/24/2022]
Abstract
Although hormones such as glucocorticoids have been broadly accepted in recent decades as general neuromodulators of memory processes, sex steroid hormones such as the potent oestrogen 17β-oestradiol have been less well recognized by the scientific community in this capacity. The predominance of females in studies of oestradiol and memory and the general (but erroneous) perception that oestrogens are 'female' hormones have probably prevented oestradiol from being more widely considered as a key memory modulator in both sexes. Indeed, although considerable evidence supports a crucial role for oestradiol in regulating learning and memory in females, a growing body of literature indicates a similar role in males. This Review discusses the mechanisms of oestradiol signalling and provides an overview of the effects of oestradiol on spatial, object recognition, social and fear memories. Although the primary focus is on data collected in females, effects of oestradiol on memory in males will be discussed, as will sex differences in the molecular mechanisms that regulate oestrogenic modulation of memory, which may have important implications for the development of future cognitive therapeutics.
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Affiliation(s)
- Lisa R Taxier
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Kellie S Gross
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
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Thiebaut C, Konan HP, Guerquin MJ, Chesnel A, Livera G, Le Romancer M, Dumond H. The Role of ERα36 in Development and Tumor Malignancy. Int J Mol Sci 2020; 21:E4116. [PMID: 32526980 PMCID: PMC7312586 DOI: 10.3390/ijms21114116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Estrogen nuclear receptors, represented by the canonical forms ERα66 and ERβ1, are the main mediators of the estrogen-dependent pathophysiology in mammals. However, numerous isoforms have been identified, stimulating unconventional estrogen response pathways leading to complex cellular and tissue responses. The estrogen receptor variant, ERα36, was cloned in 2005 and is mainly described in the literature to be involved in the progression of mammary tumors and in the acquired resistance to anti-estrogen drugs, such as tamoxifen. In this review, we will first specify the place that ERα36 currently occupies within the diversity of nuclear and membrane estrogen receptors. We will then report recent data on the impact of ERα36 expression and/or activity in normal breast and testicular cells, but also in different types of tumors including mammary tumors, highlighting why ERα36 can now be considered as a marker of malignancy. Finally, we will explain how studying the regulation of ERα36 expression could provide new clues to counteract resistance to cancer treatments in hormone-sensitive tumors.
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Affiliation(s)
- Charlène Thiebaut
- Université de Lorraine, CNRS, CRAN, F-54000 Nancy, France; (C.T.); (A.C.)
| | - Henri-Philippe Konan
- Université de Lyon, F-69000 Lyon, France; (H.-P.K.); (M.L.R.)
- INSERM U1052, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
- CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
| | - Marie-Justine Guerquin
- Laboratory of Development of the Gonads, UMRE008 Genetic Stability Stem Cells and Radiation, Université de Paris, Université Paris Saclay, CEA, F-92265 Fontenay aux Roses, France; (M.-J.G.); (G.L.)
| | - Amand Chesnel
- Université de Lorraine, CNRS, CRAN, F-54000 Nancy, France; (C.T.); (A.C.)
| | - Gabriel Livera
- Laboratory of Development of the Gonads, UMRE008 Genetic Stability Stem Cells and Radiation, Université de Paris, Université Paris Saclay, CEA, F-92265 Fontenay aux Roses, France; (M.-J.G.); (G.L.)
| | - Muriel Le Romancer
- Université de Lyon, F-69000 Lyon, France; (H.-P.K.); (M.L.R.)
- INSERM U1052, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
- CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
| | - Hélène Dumond
- Université de Lorraine, CNRS, CRAN, F-54000 Nancy, France; (C.T.); (A.C.)
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Stincic TL, Rønnekleiv OK, Kelly MJ. Diverse actions of estradiol on anorexigenic and orexigenic hypothalamic arcuate neurons. Horm Behav 2018; 104:146-155. [PMID: 29626486 PMCID: PMC6196116 DOI: 10.1016/j.yhbeh.2018.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/29/2018] [Accepted: 04/02/2018] [Indexed: 12/13/2022]
Abstract
Contribution to Special Issue on Fast effects of steroids. There is now compelling evidence for membrane-associated estrogen receptors in hypothalamic neurons that are critical for the hypothalamic control of homeostatic functions. It has been known for some time that estradiol (E2) can rapidly alter hypothalamic neuronal activity within seconds, indicating that some cellular effects can occur via membrane initiated events. However, our understanding of how E2 signals via membrane-associated receptors and how these signals impact physiological functions is only just emerging. Thus, E2 can affect second messenger systems including calcium mobilization and a plethora of kinases to alter cell excitability and even gene transcription in hypothalamic neurons. One population of hypothalamic neurons, the anorexigenic proopiomelanocortin (POMC) neurons, has long been considered to be a target of E2's actions based on gene (Pomc) expression studies. However, we now know that E2 can rapidly alter POMC neuronal activity within seconds and activate several intracellular signaling cascades that ultimately affect gene expression, actions which are critical for maintaining sensitivity to insulin in metabolically stressed states. E2 also affects the orexigenic Neuropeptide Y/Agouti-related Peptide (NPY/AgRP) neurons in similarly rapid but antagonistic manner. Therefore, this review will summarize our current state of knowledge of how E2 signals via rapid membrane-initiated and intracellular signaling cascades in POMC and NPY/AgRP neurons to regulate energy homeostasis.
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Affiliation(s)
- Todd L Stincic
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Oline K Rønnekleiv
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA; Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239, USA; Division of Neuroscience, Oregon Regional Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Martin J Kelly
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA; Division of Neuroscience, Oregon Regional Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
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Zhao J, Bian C, Liu M, Zhao Y, Sun T, Xing F, Zhang J. Orchiectomy and letrozole differentially regulate synaptic plasticity and spatial memory in a manner that is mediated by SRC-1 in the hippocampus of male mice. J Steroid Biochem Mol Biol 2018; 178:354-368. [PMID: 29452160 DOI: 10.1016/j.jsbmb.2018.02.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/07/2018] [Accepted: 02/12/2018] [Indexed: 11/23/2022]
Abstract
Hippocampal synaptic plasticity is the basis of spatial memory and cognition and is strongly regulated by both testicular androgens (testosterone, T) and hippocampal estrogens (17β-estradiol, E2) converted from T by aromatase, which is inhibited by letrozole (LET), but the contribution of each pathway to spatial memory and the associated mechanisms are unclear. In this study, we first used orchiectomy (ORX) and LET injection to investigate the effects of T and hippocampal E2 on spatial memory and hippocampal synaptic plasticity. Next, we examined the changes in steroid receptors and steroid receptor coactivator-1 (SRC-1) under these treatments. Finally, we constructed an SRC-1 RNA interference lentivirus and an AROM overexpression lentivirus to explore the roles of SRC-1 under T replacement and AROM overexpression. The results revealed spatial memory impairment only after LET. LET induced more actin depolymerization and greater losses of spines, synapses, and postsynaptic proteins compared with ORX. Moreover, although ERα and ERβ were affected by LET and ORX at similar levels, AR, GPR30, and SRC-1 were dramatically decreased by LET compared with ORX. Finally, the T and AROM overexpression-induced changes in synaptic proteins and actin polymerization were blocked by SRC-1 inhibition. These results demonstrate that testicular androgens play a limited role, whereas local E2 is more important for cognition, which may explain why castrated men such as eunuchs usually do not have cognitive disorders. These results also suggest a pivotal role of SRC-1 in the action of steroids; thus, SRC-1 may serve as a novel therapeutic target for cognitive disorders.
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Affiliation(s)
- Jikai Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Chen Bian
- Department of Military Psychology, College of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Mengying Liu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Yangang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Tao Sun
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Fangzhou Xing
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China; School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Jiqiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China.
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Kumar A, Bean LA, Rani A, Jackson T, Foster TC. Contribution of estrogen receptor subtypes, ERα, ERβ, and GPER1 in rapid estradiol-mediated enhancement of hippocampal synaptic transmission in mice. Hippocampus 2015; 25:1556-66. [PMID: 25980457 DOI: 10.1002/hipo.22475] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2015] [Indexed: 01/07/2023]
Abstract
Estradiol rapidly modulates hippocampal synaptic plasticity and synaptic transmission; however, the contribution of the various estrogen receptors to rapid changes in synaptic function is unclear. This study examined the effect of estrogen receptor selective agonists on hippocampal synaptic transmission in slices obtained from 3-5-month-old wild type (WT), estrogen receptor alpha (ERαKO), and beta (ERβKO) knockout female ovariectomized mice. Hippocampal slices were prepared 10-16 days following ovariectomy and extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 synaptic contacts before and following application of 17β-estradiol-3-benzoate (EB, 100 pM), the G-protein estrogen receptor 1 (GPER1) agonist G1 (100 nM), the ERα selective agonist propyl pyrazole triol (PPT, 100 nM), or the ERβ selective agonist diarylpropionitrile (DPN, 1 µM). Across all groups, EB and G1 increased the synaptic response to a similar extent. Furthermore, prior G1 application occluded the EB-mediated enhancement of the synaptic response and the GPER1 antagonist, G15 (100 nM), inhibited the enhancement of the synaptic response induced by EB application. We confirmed that the ERα and ERβ selective agonists (PPT and DPN) had effects on synaptic responses specific to animals that expressed the relevant receptor; however, PPT and DPN produced only a small increase in synaptic transmission relative to EB or the GPER1 agonist. We demonstrate that the increase in synaptic transmission is blocked by inhibition of extracellular signal-regulated kinase (ERK) activity. Furthermore, EB was able to increase ERK activity regardless of genotype. These results suggest that ERK activation and enhancement of synaptic transmission by EB involves multiple estrogen receptor subtypes.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Linda A Bean
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Travis Jackson
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
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Kelly MJ, Rønnekleiv OK. Minireview: neural signaling of estradiol in the hypothalamus. Mol Endocrinol 2015; 29:645-57. [PMID: 25751314 PMCID: PMC4415204 DOI: 10.1210/me.2014-1397] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/02/2015] [Indexed: 12/22/2022] Open
Affiliation(s)
- Martin J Kelly
- Departments of Physiology and Pharmacology (M.J.K., O.K.R.) and Anesthesiology and Perioperative Medicine (O.K.R.), Oregon Health and Science University, Portland, Oregon 97239; and Division of Neuroscience (M.J.K., O.K.R.), Oregon National Primate Research Center; Oregon Health and Science University, Beaverton, Oregon 97006
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N-cadherin is a Novel ERα Anchor that Protects Against 6-OHDA Damage to Dopaminergic Cells. Cell Mol Neurobiol 2013; 34:123-31. [DOI: 10.1007/s10571-013-9993-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/24/2013] [Indexed: 12/28/2022]
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Lu Y, Jiang Q, Yu L, Lu ZY, Meng SP, Su D, Burnstock G, Ma B. 17β-estradiol rapidly attenuates P2X3 receptor-mediated peripheral pain signal transduction via ERα and GPR30. Endocrinology 2013; 154:2421-33. [PMID: 23610132 DOI: 10.1210/en.2012-2119] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estrogen has been reported to affect pain perception, although the underlying mechanisms remain unclear. In this investigation, pain behavior testing, patch clamp recording, and immunohistochemistry were used on rats and transgenic mice to determine which estrogen receptors (ERs) and the related signaling pathway are involved in the rapid modulation of estrogen on P2X3 receptor-mediated events. The results showed that 17β-estradiol (E2) rapidly inhibited pain induced by α,β-methylene ATP (α,β-me-ATP), a P2X1 and P2X3 receptor agonist in ovariectomized rats and normal rats in diestrus. The ERα agonist 4,49,499-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) and G protein-coupled receptor 30 (GPR30) agonist G-1 mimicked the estrogen effect, whereas the ERβ agonist diarylpropionitrile (DPN) had no effect. In cultured rat dorsal root ganglion (DRG) neurons, PPT and G-1 but not DPN significantly attenuated α,β-me-ATP-mediated currents, with the dose-response curve of these currents shifted to the right. The inhibitory effect of E2 on P2X3 currents was blocked by G-15, a selective antagonist to the GPR30 estrogen receptor. E2 lacked this effect in DRG neurons from ERα-knockout mice but partly remained in those from ERβ-knockout mice. The P2X3 and GPR30 receptors were coexpressed in the rat DRG neurons. Furthermore, the ERK1/2 inhibitor U0126 reversed the inhibitory effect of E2 on α,β-me-ATP-induced pain and of PPT or G-1 on P2X3 receptor-mediated currents. The cAMP-protein kinase A (PKA) agonist forskolin, but not the PKC agonist phorbol-12-myristate-13-acetate (PMA), mimicked the estrogen-inhibitory effect on P2X3 receptor currents, which was blocked by another ERK1/2 inhibitor, PD98059. These results suggest that estrogen regulates P2X3-mediated peripheral pain by acting on ERα and GPR30 receptors expressed in primary afferent neurons, which probably involves the intracellular cAMP-PKA-ERK1/2 pathway.
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Affiliation(s)
- Yi Lu
- Department of Physiology, School of Pharmacy, Second Military Medical University, Shanghai 200433, People’s Republic of China
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Kisler K, Chow RH, Dominguez R. Fluorescently-Labeled Estradiol Internalization and Membrane Trafficking in Live N-38 Neuronal Cells Visualized with Total Internal Reflection Fluorescence Microscopy. ACTA ACUST UNITED AC 2013; Suppl 12. [PMID: 24353903 DOI: 10.4172/2157-7536.s12-002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Estradiol is a steroid hormone that binds and activates estradiol receptors. Activation of these receptors is known to modulate neuronal physiology and provide neuroprotection, but it is not completely understood how estradiol mediates these actions on the nervous system. Activation of a sub-population of estradiol receptor-α (ERα), originally identified as a nuclear protein, localizes to the plasma membrane and appears to be a critical step in neuroprotection against brain injury and disease. Previously we showed that estradiol stimulates the rapid and transient trafficking of plasma membrane ERα in primary hypothalamic neurons, and internalization of membrane-impermeant estradiol (E6BSA-FITC) into cortical neuron endosomes in vitro. These findings support the concept that estradiol activates and down-regulates plasma membrane ERα by triggering endocytosis. Here, we use TIRFM (total internal reflection fluorescence microscopy) to image the trafficking of E6BSA-FITC, and GFP-labeled ERα, in live cells in real time. We show that activation of plasma membrane ERs by E6BSA-FITC result in internalization of the fluorescent ligand in live N-38 neurons, an immortalized hypothalamic cell line. Pretreatment with ER antagonist ICI 182,780 decreased the number of E6BSA-FITC labeled puncta observed. We also observed in live N-38 neurons that E6BSA-FITC co-localized with FM4-64 and LysoTracker fluorescent dyes that label endosomes and lysosomes. Our results provide further evidence that plasma membrane ERα activation results in endocytosis of the receptor.
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Affiliation(s)
- Kassandra Kisler
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine of University of Southern California, USA
| | - Robert H Chow
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine of University of Southern California, USA
| | - Reymundo Dominguez
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine of University of Southern California, USA
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Varayoud J, Monje L, Moreno-Piovano GS, Galoppo GH, Luque EH, Muñoz-de-Toro M, Ramos JG. Sexually dimorphic expression of receptor-alpha in the cerebral cortex of neonatal Caiman latirostris (Crocodylia: Alligatoridae). Gen Comp Endocrinol 2012; 179:205-13. [PMID: 22964531 DOI: 10.1016/j.ygcen.2012.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 08/01/2012] [Accepted: 08/20/2012] [Indexed: 01/30/2023]
Abstract
In mammals, estrogens have been described as endocrine and paracrine modulators of neuronal differentiation and synapse formation. However, the functional role of circulating estrogens and the distribution of estrogen receptors (ERs) in the cerebral cortex of reptiles have not been clearly established. Caiman latirostris (C. latirostris) is a South American species that presents temperature-dependent sex determination (TSD). By using immunohistochemistry, we have studied the distribution of ERα in the cerebral cortex of neonatal caimans. We studied brain samples from ten-day-old TSD-females and TSD-males and from female caimans that were administered estradiol during embryonic development (hormone-dependent sex determination, HSD-females). ERα was detected in the medial (MC), dorsal (DC) and lateral (LC) cortices. ERα expression in the MC showed sex-associated differences, being significantly greater in TSD-females compared to TSD-males. Interestingly, the highest ERα expression in the MC was exhibited by HSD-females. In addition, the circulating levels of estradiol were significantly higher in females (both TSD and HSD) than in TSD-males. Double immunostaining showed that ERα is expressed by neural precursor cells (as detected by ERα/doublecortin or ERα/glial fibrillary acidic protein) and mature neurons (ERα/neuron-specific nuclear protein). Our results demonstrate that the expression of ERα in the neonatal caiman cortex is sexually dimorphic and is present in the early stages of neuronal differentiation.
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Affiliation(s)
- Jorgelina Varayoud
- Laboratorio de Endocrinología y Tumores Hormonodependientes, School of Biochemistry and Biological Sciences, Universidad Nacional del Litoral, Santa Fe, Argentina
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Regulation of ERα Protein Expression by 17β-Estradiol in Cultured Neurons of Hypothalamic Ventromedial Nucleus. Neurochem Res 2012; 38:82-9. [DOI: 10.1007/s11064-012-0891-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 08/10/2012] [Accepted: 09/10/2012] [Indexed: 12/13/2022]
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Characterization of the "sporadically lurking HAP1-immunoreactive (SLH) cells" in the hippocampus, with special reference to the expression of steroid receptors, GABA, and progenitor cell markers. Neuroscience 2012; 210:67-81. [PMID: 22421101 DOI: 10.1016/j.neuroscience.2012.02.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 01/29/2012] [Accepted: 02/14/2012] [Indexed: 02/02/2023]
Abstract
Huntingtin-associated protein 1 (HAP1) is a neural huntingtin interactor that is widely expressed as a core molecule of the stigmoid body (a neurocytoplasmic inclusion) in the limbic and hypothalamic regions and has putative protective functions against some neurodegenerative diseases (HAP1 protection hypothesis). Although HAP1 has been reported to be intimately associated with several steroid receptors, HAP1-immunoreactive (HAP1-ir) cells remain to be identified in the hippocampus, which is one of the major steroidal targets. In this study, we determined the distribution of hippocampal HAP1-ir cells in light and fluorescence microscopy and characterized their morphological relationships with steroid receptors, markers of adult neurogenesis, and the GABAergic system in adult male and female Wistar rats. HAP1-ir cells, which were sporadically distributed particularly in the subgranular zone (SGZ) of the dentate gyrus and in the interface between the stratum lacunosum-moleculare and stratum radiatum of Ammon's horn, were identified as the "sporadically lurking HAP1-ir (SLH)" cells. The SLH cells showed no clear association with neural progenitor/proliferating or migrating cell markers of adult neurogenesis, such as Ki-67, proliferating cell nuclear antigen, doublecortin, and glial fibrillary acidic protein in the SGZ, whereas all the SLH cells expressed a neuronal specific nuclear protein (NeuN). More than 90% of the SLH cells expressed nuclear estrogen receptor (ER) α but neither ERβ nor the androgen receptor, whereas glucocorticoid receptor was differently stained in the SLH cells depending on the antibodies. More than 60% of them exhibited GABA immunoreactivity in the SGZ, suggestive of basket cells, but they were distinct from the ones expressing cholecystokinin or parvalbumin. We conclude that SLH cells, which should be stable against apoptosis due to putative HAP1 protectivity, might be involved in estrogen-dependent maturation, remodeling and activation of hippocampal memory and learning functions via ERα and partly through GABAergic regulation.
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Kelly MJ. Introduction. Neuroendocrinology 2012; 96:101-2. [PMID: 22986409 DOI: 10.1159/000342130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Indexed: 11/19/2022]
Affiliation(s)
- Martin J Kelly
- Department of Physiology and Pharmacology, L334, Oregon Health and Science University, Portland, OR 97239-3098, USA
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Abstract
17β-Oestradiol (E(2)) is an important hormone signal that regulates multiple tissues and functions in the body. This review focuses on the neuroprotective actions of E(2) in the brain against cerebral ischaemia and the potential underlying mechanisms. A particular focus of the review will be on the role of E(2) to attenuate NADPH oxidase activation, superoxide and reactive oxygen species generation and reduce oxidative stress in the ischaemic brain as a potentially key neuroprotective mechanism. Evidence of a potential novel role of extranuclear oestrogen receptors in mediating E(2) signalling and neuroprotective actions is also discussed. An additional subject is the growing evidence indicating that periods of long-term oestrogen deprivation, such as those occurring after menopause or surgical menopause, may lead to loss or attenuation of E(2) signalling and neuroprotective actions in the brain, as well as enhanced sensitivity of the hippocampus to ischaemic stress damage. These findings have important implications with respect to the 'critical period hypothesis', which proposes that oestrogen replacement must be initiated at peri-menopause in humans to exert its beneficial cardiovascular and neural effects. The insights gained from these various studies will prove valuable for guiding future directions in the field.
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Affiliation(s)
- Darrell Brann
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University Augusta, GA USA 30912
- Corresponding author: Dr. Darrell W. Brann, Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, 1120 15th Street, Augusta, GA 30912, USA, Phone: 706-721-7771,
| | - Limor Raz
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University Augusta, GA USA 30912
| | - Ruimin Wang
- Hebei United University, Experimental and Research Center, Hebei United University, 57 South Jian-she Road, Tangshan, Hebei, 063600, PR China
| | - Ratna Vadlamudi
- Department of Obstetrics & Gynecology, University of Texas Health Science Center at San Antonio, Floyd Curl Drive, San Antonio TX 78229
| | - Quanguang Zhang
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University Augusta, GA USA 30912
- Co-Corresponding author: Dr. Quanguang Zhang, Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, 1120 15th Street, Augusta, GA 30912, USA, Phone: 706-721-7771,
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Welsh AW, Lannin DR, Young GS, Sherman ME, Figueroa JD, Henry NL, Ryden L, Kim C, Love RR, Schiff R, Rimm DL. Cytoplasmic estrogen receptor in breast cancer. Clin Cancer Res 2011; 18:118-26. [PMID: 21980134 DOI: 10.1158/1078-0432.ccr-11-1236] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE In addition to genomic signaling, it is accepted that estrogen receptor-α (ERα) has nonnuclear signaling functions, which correlate with tamoxifen resistance in preclinical models. However, evidence for cytoplasmic ER localization in human breast tumors is less established. We sought to determine the presence and implications of nonnuclear ER in clinical specimens. EXPERIMENTAL DESIGN A panel of ERα-specific antibodies (SP1, MC20, F10, 60c, and 1D5) was validated by Western blot and quantitative immunofluorescent (QIF) analysis of cell lines and patient controls. Then eight retrospective cohorts collected on tissue microarrays were assessed for cytoplasmic ER. Four cohorts were from Yale (YTMA 49, 107, 130, and 128) and four others (NCI YTMA 99, South Swedish Breast Cancer Group SBII, NSABP B14, and a Vietnamese Cohort) from other sites around the world. RESULTS Four of the antibodies specifically recognized ER by Western and QIF analysis, showed linear increases in amounts of ER in cell line series with progressively increasing ER, and the antibodies were reproducible on YTMA 49 with Pearson correlations (r(2) values) ranging from 0.87 to 0.94. One antibody with striking cytoplasmic staining (MC20) failed validation. We found evidence for specific cytoplasmic staining with the other four antibodies across eight cohorts. The average incidence was 1.5%, ranging from 0 to 3.2%. CONCLUSIONS Our data show ERα is present in the cytoplasm in a number of cases using multiple antibodies while reinforcing the importance of antibody validation. In nearly 3,200 cases, cytoplasmic ER is present at very low incidence, suggesting its measurement is unlikely to be of routine clinical value.
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Affiliation(s)
- Allison W Welsh
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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17
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Estradiol rapidly regulates membrane estrogen receptor alpha levels in hypothalamic neurons. J Neurosci 2010; 30:12589-96. [PMID: 20861365 DOI: 10.1523/jneurosci.1038-10.2010] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Estrogen receptors (ERs) and estrogen-binding proteins have been localized intracellularly and on the cell surface. The membrane-associated proteins initiate signaling that activates a myriad of cellular responses including the modulation of ion channels and ultimately transcription. Although many of the downstream actions of membrane ERs, including ERα and ERβ, have been characterized, the mechanisms regulating membrane ER levels have remained elusive in the nervous system. In the present study, we used surface biotinylation to identify and study the estradiol regulation of membrane ERα in mixed-sex, cultured hypothalamic neurons from rat. Following surface biotinylation, Western blot analysis revealed full-length 66 kDa ERα and several ERα splice variants, most notably a biotinylated 52 kDa ERα-immunoreactive protein. Treatment of the neurons with estradiol caused a rapid and transient increase of the biotinylated 52 kDa and 66 kDa ERα proteins in the plasma membrane. Exposure of the neurons to estradiol also significantly increased internalization of 52 kDa and 66 kDa ERα membrane proteins, a measure of receptor activation. In the hypothalamus, membrane ERα signaling depends on transactivation of metabotropic glutamate receptor-1a (mGluR1a). Estradiol treatment increased the internalization of mGluR1a in parallel with ERα, a finding consistent with the hypothesis of an ERα-mGluR1a signaling unit. These results demonstrate that estradiol regulates the amount of ERα in the membrane, suggesting estradiol can regulate its own membrane signaling.
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18
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McEwen BS. Stress, sex, and neural adaptation to a changing environment: mechanisms of neuronal remodeling. Ann N Y Acad Sci 2010; 1204 Suppl:E38-59. [PMID: 20840167 PMCID: PMC2946089 DOI: 10.1111/j.1749-6632.2010.05568.x] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The adult brain is much more resilient and adaptable than previously believed, and adaptive structural plasticity involves growth and shrinkage of dendritic trees, turnover of synapses, and limited amounts of neurogenesis in the forebrain, especially the dentate gyrus of the hippocampal formation. Stress and sex hormones help to mediate adaptive structural plasticity, which has been extensively investigated in the hippocampus and to a lesser extent in the prefrontal cortex and amygdala, all brain regions that are involved in cognitive and emotional functions. Stress and sex hormones exert their effects on brain structural remodeling through both classical genomic as well as non-genomic mechanisms, and they do so in collaboration with neurotransmitters and other intra- and extracellular mediators. This review will illustrate the actions of estrogen on synapse formation in the hippocampus and the process of stress-induced remodeling of dendrites and synapses in the hippocampus, amygdala, and prefrontal cortex. The influence of early developmental epigenetic events, such as early life stress and brain sexual differentiation, is noted along with the interactions between sex hormones and the effects of stress on the brain. Because hormones influence brain structure and function and because hormone secretion is governed by the brain, applied molecular neuroscience techniques can begin to reveal the role of hormones in brain-related disorders and the treatment of these diseases. A better understanding of hormone-brain interactions should promote more flexible approaches to the treatment of psychiatric disorders, as well as their prevention through both behavioral and pharmaceutical interventions.
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Affiliation(s)
- Bruce S McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065, USA.
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19
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Watson CS, Alyea RA, Cunningham KA, Jeng YJ. Estrogens of multiple classes and their role in mental health disease mechanisms. Int J Womens Health 2010; 2:153-66. [PMID: 21072308 PMCID: PMC2971739 DOI: 10.2147/ijwh.s6907] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Indexed: 12/21/2022] Open
Abstract
Gender and sex hormones can influence a variety of mental health states, including mood, cognitive development and function, and vulnerability to neurodegenerative diseases and brain damage. Functions of neuronal cells may be altered by estrogens depending upon the availability of different physiological estrogenic ligands; these ligands and their effects vary with life stages, the genetic or postgenetic regulation of receptor levels in specific tissues, or the intercession of competing nonphysiological ligands (either intentional or unintentional, beneficial to health or not). Here we review evidence for how different estrogens (physiological and environmental/dietary), acting via different estrogen receptor subtypes residing in alternative subcellular locations, influence brain functions and behavior. We also discuss the families of receptors and transporters for monoamine neurotransmitters and how they may interact with the estrogenic signaling pathways.
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20
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Rowan MP, Berg KA, Milam SB, Jeske NA, Roberts JL, Hargreaves KM, Clarke WP. 17beta-estradiol rapidly enhances bradykinin signaling in primary sensory neurons in vitro and in vivo. J Pharmacol Exp Ther 2010; 335:190-6. [PMID: 20647494 DOI: 10.1124/jpet.110.167445] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Many studies have demonstrated that premenopausal women are at increased risk for various pain disorders. Pain-sensing neurons, termed "nociceptors," in the trigeminal ganglia (TG) and dorsal root ganglia (DRG) express receptors for inflammatory mediators and noxious physical stimuli and transmit signals for central processing of pain sensation. Estrogen receptors (ERs) are also expressed on nociceptors in the TG and DRG, and there is ample literature to suggest that activation of ERs can influence pain mechanisms. However, the mechanism for ER modulation of nociceptor activity is incompletely understood. The aim of this study was to characterize the effect of 17β-estradiol (17β-E(2)) on signaling of the inflammatory mediator bradykinin (BK) in primary cultures of rat sensory neurons and a behavioral model of thermal allodynia in rats. Here, we show that exposure to 17β-E(2) rapidly (within 15 min) enhanced responses to BK in vitro and in vivo. The 17β-E(2)-mediated enhancement of BK signaling was not blocked by the transcription inhibitor anisomycin and was mediated by a membrane-associated ER. The effect of 17β-E(2) to enhance BK responses required activation of β1-containing, RGD-binding integrins. These data show that 17β-E(2) rapidly enhances inflammatory mediator responses both in vitro and in vivo and suggest that 17β-E(2) acting at primary sensory pain neurons may participate in regulating the sensitivity of women to painful stimuli.
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Affiliation(s)
- Matthew P Rowan
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA
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21
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Abstract
Although the effects of estrogen on sexual behavior in mammals are well known, its role on other types of behavior, including cognition, have only recently been recognized. This review summarizes work conducted in our laboratory and others with the aim of identifying the effects of estrogen on cognitive functions. The first section will briefly describe the neurobiology of estrogen. The second section will discuss the effects of estrogen on cognitive behaviors in mammals, as well as the physiological relevance of these effects and their applicability to human health and disease. The third section will detail the role of estrogen on working memory in humans and nonhuman primates, and in rodents. Finally, the concluding section will briefly describe the relationship between estrogen and the aging brain.
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Affiliation(s)
- Antonella Gasbarri
- a Department of Biomedical Sciences and Technologies, Faculty of Sciences of Education, University of L'Aquila, via Vetoio, 67100 L'Aquila, Italy.
| | - Assunta Pompili
- b Department of Biomedical Sciences and Technologies, Faculty of Sciences of Education, University of L'Aquila, via Vetoio, 67100 L'Aquila, Italy.
| | - Maria Clotilde Tavares
- c Department of Physiological Sciences, Laboratory of Neurosciences and Behavior, Center of Primatology, University of Brasília, Campus Asa Norte, CEP 70910-900 Brasília, DF, Brazil.
| | - Carlos Tomaz
- d Department of Physiological Sciences, Laboratory of Neurosciences and Behavior, Institute of Biology, University of Brasília, Campus Asa Norte, CEP 70910-900 Brasília, DF, Brazil.
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22
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Chung TH, Wang SM, Liang JY, Yang SH, Wu JC. The interaction of estrogen receptor alpha and caveolin-3 regulates connexin43 phosphorylation in metabolic inhibition-treated rat cardiomyocytes. Int J Biochem Cell Biol 2009; 41:2323-33. [PMID: 19523531 DOI: 10.1016/j.biocel.2009.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/19/2009] [Accepted: 06/03/2009] [Indexed: 11/19/2022]
Abstract
Caveolin-3, the major caveolin isoform in cardiomyocytes, plays an important role in the rapid signaling pathways initiated by stimulation of the membrane-associated molecules. To examine the role of caveolin-3 in regulating estrogen receptor alpha in cardiomyocytes, we investigate whether the membrane estrogen receptor alpha associates with caveolin-3 and whether this association is linked to the 17beta-estradiol-mediated signals. In control cardiomyocytes, following discontinuous sucrose gradient centrifugation, caveolin-3 was found predominantly in the lipid raft buoyant fractions, whereas it was distributed to both the buoyant and non-lipid raft heavy fractions following metabolic inhibition treatment. Confocal microscopy showed that estrogen receptor alpha co-localized with caveolin-3 on the plasma membrane of neonatal and adult rat cardiomyocytes. This membrane labeling of estrogen receptor alpha was not seen following treatment with the cholesterol-depleting agent methyl-beta-cyclodextrin (5mM), whereas metabolic inhibition had little effect on the membrane distribution of estrogen receptor alpha. Metabolic inhibition induced tyrosine phosphorylation of caveolin-3 and decreased its association with estrogen receptor alpha, both effects being mediated via a Src activation mechanism, since they were inhibited by the selective tyrosine kinase inhibitor PP2. Metabolic inhibition also induced tyrosine phosphorylation of connexin43 and increased its association with c-Src, both effects being prevented by 17beta-estradiol (200 nM). The effect of 17beta-estradiol on metabolic inhibition-induced tyrosine phosphorylation of connexin43 was inhibited by the specific estrogen receptor antagonist ICI182780. These data identify cardiac caveolin-3 as juxtamembrane scaffolding for estrogen receptor alpha docking at caveolae, which provide a unique compartment for conveying 17beta-estradiol-elicited, rapid signaling to regulate connexin43 phosphorylation during ischemia.
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Affiliation(s)
- Tun-Hui Chung
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan
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23
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McCullar JS, Oesterle EC. Cellular targets of estrogen signaling in regeneration of inner ear sensory epithelia. Hear Res 2009; 252:61-70. [PMID: 19450430 PMCID: PMC2975607 DOI: 10.1016/j.heares.2009.01.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 01/16/2009] [Accepted: 01/22/2009] [Indexed: 01/19/2023]
Abstract
Estrogen signaling in auditory and vestibular sensory epithelia is a newly emerging focus propelled by the role of estrogen signaling in many other proliferative systems. Understanding the pathways with which estrogen interacts can provide a means to identify how estrogen may modulate proliferative signaling in inner ear sensory epithelia. Reviewed herein are two signaling families, EGF and TGFbeta. Both pathways are involved in regulating proliferation of supporting cells in mature vestibular sensory epithelia and have well characterized interactions with estrogen signaling in other systems. It is becoming increasingly clear that elucidating the complexity of signaling in regeneration will be necessary for development of therapeutics that can initiate regeneration and prevent progression to a pathogenic state.
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Affiliation(s)
- Jennifer S. McCullar
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, CHDD CD176, P.O. Box 357923, Seattle, WA 98195, USA
| | - Elizabeth C. Oesterle
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, CHDD CD176, P.O. Box 357923, Seattle, WA 98195, USA
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24
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Massinen S, Tammimies K, Tapia-Páez I, Matsson H, Hokkanen ME, Söderberg O, Landegren U, Castrén E, Gustafsson JA, Treuter E, Kere J. Functional interaction of DYX1C1 with estrogen receptors suggests involvement of hormonal pathways in dyslexia. Hum Mol Genet 2009; 18:2802-12. [PMID: 19423554 DOI: 10.1093/hmg/ddp215] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Dyslexia, or specific reading disability, is the unexpected failure in learning to read and write when intelligence and senses are normal. One of the susceptibility genes, DYX1C1, has been implicated in neuronal migration, but little is known about its interactions and functions. As DYX1C1 was suggested to interact with the U-box protein CHIP (carboxy terminus of Hsc70-interacting protein), which also participates in the degradation of estrogen receptors alpha (ERalpha) and beta (ERbeta), we hypothesized that the effects of DYX1C1 might be at least in part mediated through the regulation of ERs. ERs have shown to be important in brain development and cognitive functions. Indeed, we show that DYX1C1 interacts with both ERs in the presence of 17beta-estradiol, as determined by co-localization, co-immunoprecipitation and proximity ligation assays. Protein levels of endogenous ERalpha or exogenous ERbeta were reduced upon over-expression of DYX1C1, resulting in decreased transcriptional responses to 17beta-estradiol. Furthermore, we detected in vivo complexes of DYX1C1 with ERalpha or ERbeta at endogenous levels along neurites of primary rat hippocampal neurons. Taken together, our data suggest that DYX1C1 is involved in the regulation of ERalpha and ERbeta, and may thus affect the brain development and regulate cognitive functions. These findings provide novel insights into the function of DYX1C1 and link neuronal migration and developmental dyslexia to the estrogen-signaling effects in the brain.
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Affiliation(s)
- Satu Massinen
- Department of Medical Genetics, University of Helsinki and Folkhälsan Institute of Genetics, Helsinki, Finland
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25
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17beta-estradiol-mediated neuroprotection and ERK activation require a pertussis toxin-sensitive mechanism involving GRK2 and beta-arrestin-1. J Neurosci 2009; 29:4228-38. [PMID: 19339617 DOI: 10.1523/jneurosci.0550-09.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
17-beta-Estradiol (E2) is a steroid hormone involved in numerous bodily functions, including several brain functions. In particular, E2 is neuroprotective against excitotoxicity and other forms of brain injuries, a property that requires the extracellular signal-regulated kinase (ERK) pathway and possibly that of other signaling molecules. The mechanism and identity of the receptor(s) involved remain unclear, although it has been suggested that E2 receptor alpha (ERalpha) and G proteins are involved. We, therefore, investigated whether E2-mediated neuroprotection and ERK activation were linked to pertussis toxin (PTX)-sensitive G-protein-coupled effector systems. Biochemical and image analysis of organotypic hippocampal slices and cortical neuronal cultures showed that E2-mediated neuroprotection as well as E2-induced ERK activation were sensitive to PTX. The sensitivity to PTX suggested a possible role of G-protein- and beta-arrestin-mediated mechanisms. Western immunoblots from E2-treated cortical neuronal cultures revealed an increase in phosphorylation of both G-protein-coupled receptor-kinase 2 and beta-arrestin-1, a G-protein-coupled receptor adaptor protein. Transfection of neurons with beta-arrestin-1 small interfering RNA prevented E2-induced ERK activation. Coimmunoprecipitation experiments indicated that E2 increased the recruitment of beta-arrestin-1 and c-Src to ERalpha. These findings suggested that ERalpha is regulated by a mechanism associated with receptor desensitization and downregulation. In support of this idea, we found that E2 treatment of cortical synaptoneurosomes resulted in internalization of ERalpha, whereas treatment of cortical neurons with the ER agonists E-6-BSA-FITC [beta-estradiol-6-(O-carboxymethyl)oxime-bovine serum albumin conjugated with fluorescein isothiocyanate] and E-6-biotin [1,3,5(10)-estratrien-3,17beta-diol-6-one-6-carboxymethloxime-NH-propyl-biotin] resulted in agonist internalization. These results demonstrate that E2-mediated neuroprotection and ERK activation involve ERalpha activation of G-protein- and beta-arrestin-mediated mechanisms.
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26
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Jiang P, Kong Y, Zhang XB, Wang W, Liu CF, Xu TL. Glycine receptor in rat hippocampal and spinal cord neurons as a molecular target for rapid actions of 17-beta-estradiol. Mol Pain 2009; 5:2. [PMID: 19138413 PMCID: PMC2651124 DOI: 10.1186/1744-8069-5-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 01/12/2009] [Indexed: 12/20/2022] Open
Abstract
Glycine receptors (GlyRs) play important roles in regulating hippocampal neural network activity and spinal nociception. Here we show that, in cultured rat hippocampal (HIP) and spinal dorsal horn (SDH) neurons, 17-β-estradiol (E2) rapidly and reversibly reduced the peak amplitude of whole-cell glycine-activated currents (IGly). In outside-out membrane patches from HIP neurons devoid of nuclei, E2 similarly inhibited IGly, suggesting a non-genomic characteristic. Moreover, the E2 effect on IGly persisted in the presence of the calcium chelator BAPTA, the protein kinase inhibitor staurosporine, the classical ER (i.e. ERα and ERβ) antagonist tamoxifen, or the G-protein modulators, favoring a direct action of E2 on GlyRs. In HEK293 cells expressing various combinations of GlyR subunits, E2 only affected the IGly in cells expressing α2, α2β or α3β subunits, suggesting that either α2-containing or α3β-GlyRs mediate the E2 effect observed in neurons. Furthermore, E2 inhibited the GlyR-mediated tonic current in pyramidal neurons of HIP CA1 region, where abundant GlyR α2 subunit is expressed. We suggest that the neuronal GlyR is a novel molecular target of E2 which directly inhibits the function of GlyRs in the HIP and SDH regions. This finding may shed new light on premenstrual dysphoric disorder and the gender differences in pain sensation at the CNS level.
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Affiliation(s)
- Peng Jiang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, PR China
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27
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Fehrenbacher JC, Loverme J, Clarke W, Hargreaves KM, Piomelli D, Taylor BK. Rapid pain modulation with nuclear receptor ligands. ACTA ACUST UNITED AC 2008; 60:114-24. [PMID: 19162071 DOI: 10.1016/j.brainresrev.2008.12.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2008] [Indexed: 12/13/2022]
Abstract
We discuss and present new data regarding the physiological and molecular mechanisms of nuclear receptor activation in pain control, with a particular emphasis on non-genomic effects of ligands at peroxisome proliferator-activated receptor (PPAR), GPR30, and classical estrogen receptors. PPARalpha agonists rapidly reduce both acute and chronic pain in a number of pain assays. These effects precede transcriptional anti-inflammatory actions, and are mediated in part by IK(ca) and BK(ca) channels on DRG neurons. In contrast to the peripheral site of action of PPARalpha ligands, the dorsal horn supports the expression of PPARgamma. Intrathecal administration of PPARgamma ligands rapidly (< or =5 min) attenuated mechanical and thermal hypersensitivity associated with nerve injury in a dose-dependent manner that could be blocked with PPARgamma antagonists. By contrast, a PPARgamma antagonist itself rapidly increased the mechanical allodynia associated with nerve injury. These data suggest that ligand-dependent, non-genomic activation of spinal PPARgamma decreases behavioral signs of inflammatory and neuropathic pain. We also report that the GPR30 is expressed on cultured sensory neurons, that activation of the receptor elicits signaling to increase calcium accumulation. This signaling may contribute to increased neuronal sensitivity as treatment with the GPR30 agonist induces hyperalgesia. Finally, application of the membrane-impermeable 17beta-E(2)-BSA rapidly (within 15 min) enhanced BK-stimulated inositol phosphate (IP) accumulation and PGE(2)-mediated cAMP accumulation in trigeminal ganglion cultures. We conclude that nuclear receptor ligands may operate through rapid, non-genomic mechanisms to modulate inflammatory and neuropathic pain.
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Affiliation(s)
- Jill C Fehrenbacher
- Department of Endodontics, University of Texas Health Science Center, San Antonio, TX, USA
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28
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Estrogen facilitates both phosphatidylinositol 3-kinase/Akt and ERK1/2 mitogen-activated protein kinase membrane signaling required for long-term neuropeptide Y transcriptional regulation in clonal, immortalized neurons. J Neurosci 2008; 28:6473-82. [PMID: 18562618 DOI: 10.1523/jneurosci.0514-08.2008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
It is established that increases in neuropeptide Y (NPY) expression are associated with hyperphagia and obesity. These effects can be reversed by estrogen, a recognized anorexigen. We found that 17beta-estradiol (E(2)) regulates biphasic NPY gene expression in a clonal, immortalized hypothalamic cell line, N-38, through estrogen receptor (ER) action at the level of the NPY promoter. However, rapid, nongenomic actions of estrogen, linked to the phosphatidylinositol 3-kinase (PI3-K)/Akt and ERK1/2 mitogen-activated protein kinase (MAPK) pathways, may also play a role. We therefore examined the changes in the phosphorylation status of Akt, ERK1/2, and cAMP response element-binding protein (CREB) after treatment with 10 nm E(2) in the N-38 neurons and found activation of these signaling proteins within 5-30 min. We also demonstrated possible cross talk between the estrogen-activated PI3-K/Akt and MAPK/extracellular signal-regulated kinase pathways using pharmacological inhibitors. We find that only ERalpha is involved in the early signaling events using the ERalpha agonist 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol and the ERbeta agonist 2,3-bis(4-hydroxyphenyl)-propionitrile. Furthermore, we can detect colocalization of ERalpha and caveolin-1, a membrane-associated signaling protein. Remarkably, we find that the membrane-mediated events are critical for the long-term estrogen-mediated repression of NPY gene expression that can be mapped to within -97 bp of the NPY promoter. To link the early signaling events to downstream effectors, we detected induction of c-fos and inactivation of MSK-1 by estrogen and binding of CREB to this minimal promoter region. These observations suggest that rapid estrogen-mediated signaling is mediated by ERalpha, and the signal transduction events potentiate the genomic actions of estrogen on NPY gene expression in the N-38 NPY neurons.
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29
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O'Neill EE, Blewett AR, Loria PM, Greene GL. Modulation of alphaCaMKII signaling by rapid ERalpha action. Brain Res 2008; 1222:1-17. [PMID: 18572149 DOI: 10.1016/j.brainres.2008.05.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 04/19/2008] [Accepted: 05/04/2008] [Indexed: 10/22/2022]
Abstract
The estrogen receptor (ER) subtypes, ERalpha and ERbeta, modulate numerous signaling cascades in the brain to result in a variety of cell fates including neuronal differentiation. We report here that 17beta-estradiol (E2) rapidly stimulates the autophosphorylation of alpha-Ca(2+)/calmodulin-dependent kinase II (alphaCaMKII) in immortalized NLT GnRH neurons, primary hippocampal neurons, and Cos7 cells co-transfected with ERalpha and alphaCaMKII. The E2-induced alphaCaMKII autophosphorylation is ERalpha- and Ca(2+)/calmodulin (CaM)-dependent. Interestingly, the hormone-dependent association of ERalpha with alphaCaMKII attenuates the positive effect of E2 on alphaCaMKII autophosphorylation, suggesting that ERalpha plays a complex role in modulating alphaCaMKII activity and may function to fine-tune alphaCaMKII-triggered signaling events. However, it appears as though the activating signal of E2 dominates the negative effect of ER since there is a clear, positive downstream response to E2-activated alphaCaMKII; pharmacological inhibitors and RNAi technology show that targets of ERalpha-mediated alphaCaMKII signaling include extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP response element-binding protein (CREB), and microtubule associated protein 2 (MAP2). These findings suggest a novel model for the modulation of alphaCaMKII signaling by ERalpha, which provides a molecular link as to how E2 might influence brain function.
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Affiliation(s)
- Erin E O'Neill
- The Ben May Department for Cancer Research, The University of Chicago, Chicago, IL 60637, USA
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30
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Vasudevan N, Pfaff DW. Non-genomic actions of estrogens and their interaction with genomic actions in the brain. Front Neuroendocrinol 2008; 29:238-57. [PMID: 18083219 DOI: 10.1016/j.yfrne.2007.08.003] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Accepted: 08/14/2007] [Indexed: 12/16/2022]
Abstract
Ligands for the nuclear receptor superfamily have at least two mechanisms of action: (a) classical transcriptional regulation of target genes (genomic mechanisms); and (b) non-genomic actions, which are initiated at the cell membrane, which could also impact transcription. Though transcriptional mechanisms are increasingly well understood, membrane-initiated actions of these ligands are incompletely understood. This has led to considerable debate over the physiological relevance of membrane-initiated actions of hormones versus genomic actions of hormones, with genomic actions predominating in the endocrine field. There is good evidence that the membrane-limited actions of hormones, particularly estrogens, involve the rapid activation of kinases and the release of calcium and that these are linked to physiologically relevant scenarios in the brain. We show evidence in this review, that membrane actions of estrogens, which activate these rapid signaling cascades, can also potentiate nuclear transcription in both the central nervous system and in non-neuronal cell lines. We present a theoretical scenario which can be used to understand this phenomenon. These signaling cascades may occur in parallel or in series but subsequently, converge at the modification of transcriptionally relevant molecules such as nuclear receptors and/or coactivators. In addition, other non-cognate hormones or neurotransmitters may also activate cascades to crosstalk with estrogen receptor-mediated transcription, though the relevance of this is less clear. The idea that coupling between membrane-initiated and genomic actions of hormones is a novel idea in neuroendocrinology and provides us with a unified view of hormone action in the central nervous system.
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Affiliation(s)
- Nandini Vasudevan
- Cell and Molecular Biology Department, Tulane University, LA 70118, USA.
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31
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De Loof A. Ecdysteroids, juvenile hormone and insect neuropeptides: Recent successes and remaining major challenges. Gen Comp Endocrinol 2008; 155:3-13. [PMID: 17716674 DOI: 10.1016/j.ygcen.2007.07.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 07/02/2007] [Accepted: 07/04/2007] [Indexed: 11/21/2022]
Abstract
In the recent decade, tremendous progress has been realized in insect endocrinology as the result of the application of a variety of advanced methods in neuropeptidome- and receptor research. Hormones of which the existence had been shown by bioassays four decades ago, e.g. bursicon (a member of the glycoprotein hormone family) and pupariation factor (Neb-pyrokinin 2, a myotropin), could be identified, along with their respective receptors. In control of diurnal rhythms, clock genes got company from the neuropeptide Pigment Dispersing Factor (PDF), of which the receptor could also be identified. The discovery of Inka cells and their function in metamorphosis was a true hallmark. Analysis of the genomes of Caenorhabditis elegans, Drosophila melanogaster and Apis mellifera yielded about 75, 100 and 200 genes coding for putative signaling peptides, respectively, corresponding to approximately 57, 100 and 100 peptides of which the expression could already be proven by means of mass spectrometry. The comparative approach invertebrates-vertebrates recently yielded indications for the existence of counterparts in insects for prolactin, atrial natriuretic hormone and Growth Hormone Releasing Hormone (GRH). Substantial progress has been realized in identifying the Halloween genes, a membrane receptor(s) for ecdysteroids, a nuclear receptor for methylfarnesoate, and dozens of GPCRs for insect neuropeptides. The major remaining challenges concern the making match numerous orphan GPCRs with orphan peptidic ligands, and elucidating their functions. Furthermore, the endocrine control of growth, feeding-digestion, and of sexual differentiation, in particular of males, is still poorly understood. The finding that the prothoracic glands produce an autocrine factor with growth factor-like properties and secrete proteins necessitates a reevaluation of their role in development.
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Affiliation(s)
- Arnold De Loof
- Zoological Institute of the Katholieke Universiteit Leuven, Naamsestraat 59, 3000 Leuven, Belgium
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Sakamoto H, Matsuda KI, Hosokawa K, Nishi M, Morris JF, Prossnitz ER, Kawata M. Expression of G protein-coupled receptor-30, a G protein-coupled membrane estrogen receptor, in oxytocin neurons of the rat paraventricular and supraoptic nuclei. Endocrinology 2007; 148:5842-50. [PMID: 17872373 DOI: 10.1210/en.2007-0436] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The regulatory actions of estrogens on magnocellular oxytocin (OT) neurons of the paraventricular and supraoptic nuclei are well documented. Although the expression and distribution of nuclear estrogen receptor-beta, but not estrogen receptor-alpha, in the OT neuron has been described, the nuclear receptors may not explain all aspects of estrogen function in the hypothalamic OT neuron. Recently a G protein-coupled receptor (GPR) for estrogens, GPR30, has been identified as a membrane-localized estrogen receptor in several cancer cell lines. In this study, we therefore investigated the expression and localization of GPR30 in magnocellular OT neurons to understand the mode of rapid estrogen actions within these neurons. Here we show that, in the paraventricular nucleus and supraoptic nucleus, GPR30 is expressed in magnocellular OT neurons at both mRNA and protein levels but is not expressed in vasopressin neurons. Specific markers for intracellular organelles and immunoelectron microscopy revealed that GPR30 was localized mainly in the Golgi apparatus of the neurons but could not be detected at the cell surface. In addition, the expression of GPR30 is also detected in the neurohypophysis. These results suggest that GPR30 may serve primarily as a nongenomic transducer of estrogen actions in the hypothalamo-neurohypophyseal system.
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Affiliation(s)
- Hirotaka Sakamoto
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
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Watson CS, Alyea RA, Jeng YJ, Kochukov MY. Nongenomic actions of low concentration estrogens and xenoestrogens on multiple tissues. Mol Cell Endocrinol 2007; 274:1-7. [PMID: 17601655 PMCID: PMC1986712 DOI: 10.1016/j.mce.2007.05.011] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 05/17/2007] [Indexed: 10/23/2022]
Abstract
Nongenomic estrogenic mechanisms offer an opportunity to explain the conundrum of environmental estrogen and plant estrogen effects on cells and animals at the very low concentrations which are prevalent in our environments and diets. Heretofore the actions of these compounds have not been adequately accounted for by laboratory tests utilizing assays for actions only via the genomic pathway of steroid action and the nuclear forms of estrogen receptor alpha and beta. Membrane versions of these receptors, and the newly described GPR30 (7TMER) receptor protein provide explanations for the more potent actions of xenoestrogens. The effects of estrogens on many tissues demand a comprehensive assessment of the receptors, receptor levels, and mechanisms that might be involved, to determine which of these estrogen mimetic compounds are harmful and which might even be used therapeutically, depending upon the life stage at which we are exposed to them.
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Affiliation(s)
- C S Watson
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0645, USA.
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Jelks KB, Wylie R, Floyd CL, McAllister AK, Wise P. Estradiol targets synaptic proteins to induce glutamatergic synapse formation in cultured hippocampal neurons: critical role of estrogen receptor-alpha. J Neurosci 2007; 27:6903-13. [PMID: 17596438 PMCID: PMC6672227 DOI: 10.1523/jneurosci.0909-07.2007] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Estradiol mediates structural changes at synapses of the hippocampus, an area in the brain important for learning and memory. This study was designed to test the hypothesis that estradiol mediates subcellular changes of synaptic proteins to induce new synapses via an estrogen receptor (ER)-mediated process. To elucidate the mechanisms involved in glutamatergic synapse formation, we investigated effects of estradiol on synaptic proteins in cultured hippocampal neurons using immunocytochemistry and confocal microscopy. Synaptic protein distribution and size were identified with antibodies to the presynaptic vesicular glutamate transporter protein (vGlut1) and postsynaptic NMDA receptor (NR1 subunit). We observed an increase in synapse density, as detected by NR1 and vGlut1 colocalization, along dendrites of neurons cultured in steroid-stripped media and exposed to estradiol (10 nM) for 48 h. Additionally, the NR1 subunit was enriched at synaptic clusters. Immunocytochemistry and confocal imaging revealed punctate staining of extranuclear ERs along dendrites of hippocampal neurons expressing NR1. Estradiol increased the density of both ER-alpha and ER-beta protein clusters along dendrites. To test whether ERs play an important functional role in the estradiol-induced synaptogenesis, we used the ER antagonist [7alpha,17beta-[9[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol (ICI 182,780)] and the ER-alpha- and ER-beta-specific agonists [1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) and 2,3-bis(4-hydroxyphenyl) propionitrile (DPN), respectively]. ICI 182,780 blocked the increase in synapse density. Treatment with PPT, but not DPN, induced significant increases in synapse density that mimicked treatment with estradiol. Together, our results demonstrate that estradiol stimulates glutamatergic synapse formation in the developing hippocampus through an ER-alpha-dependent mechanism. These findings carry profound implications regarding the potential of estrogen to influence learning, memory, and possibly hormone-modulated neurodegeneration.
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Affiliation(s)
| | - Rebecca Wylie
- Department of Neurobiology, Physiology, and Behavior and
| | - Candace L. Floyd
- Department of Physical Medicine and Rehabilitation, University of Alabama–Birmingham, Birmingham, Alabama 35249-7330, and
| | | | - Phyllis Wise
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195-1237
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Marin R, Ramírez CM, González M, González-Muñoz E, Zorzano A, Camps M, Alonso R, Díaz M. Voltage-dependent anion channel (VDAC) participates in amyloid beta-induced toxicity and interacts with plasma membrane estrogen receptor alpha in septal and hippocampal neurons. Mol Membr Biol 2007; 24:148-60. [PMID: 17453421 DOI: 10.1080/09687860601055559] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Voltage-dependent anion channel (VDAC) is a porin known by its role in metabolite transport across mitochondria and participation in apoptotic processes. Although traditionally accepted to be located within mitochondrial outer membrane, some data has also reported its presence at the plasma membrane level where it seems to participate in regulation of normal redox homeostasis and apoptosis. Here, exposure of septal SN56 and hippocampal HT22 cells to specific anti-VDAC antibodies prior to amyloid beta (Abeta) peptide was observed to prevent neurotoxicity. In these cell lines, we identified a VDAC form associated with the plasma membrane that seems to be particularly abundant in caveolae. The two membrane-related isoforms of estrogen receptor alpha (mERalpha) (80 and 67 kDa), known in SN56 cells to participate in estrogen-induced neuroprotection against Abeta injury, were also observed to be present in caveolae. Interestingly, we demonstrated for the first time that both VDAC and mERalpha interact at the plasma membrane of these neurons as well as in microsomal fractions of the corresponding murine septal and hippocampal tissues. These proteins were also shown to associate with caveolin-1, thereby corroborating their presence in caveolar microdomains. Taken together, these results suggest that VDAC-mERalpha association at the plasma membrane level may participate in the modulation of Abeta-induced cell death.
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Affiliation(s)
- Raquel Marin
- Laboratory of Cellular Neurobiology, Department of Physiology & Institute of Biomedical Technologies, University of La Laguna, School of Medicine, Santa Cruz de Tenerife, Spain.
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Sato K, Akaishi T, Matsuki N, Ohno Y, Nakazawa K. beta-Estradiol induces synaptogenesis in the hippocampus by enhancing brain-derived neurotrophic factor release from dentate gyrus granule cells. Brain Res 2007; 1150:108-20. [PMID: 17433270 DOI: 10.1016/j.brainres.2007.02.093] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 02/09/2007] [Accepted: 02/28/2007] [Indexed: 01/08/2023]
Abstract
We investigated the effect of beta-estradiol (E2) on synaptogenesis in the hippocampus using organotypic hippocampal slice cultures and subregional hippocampal neuron cultures. E2 increased the expression of PSD95, a postsynaptic marker, specifically in stratum lucidum of Cornu Ammonis 3 (CA3SL) in cultured hippocampal slices. E2 also increased the spine density at the proximal site of CA3 apical dendrites in CA3SL and PSD95 was clustered on these spine heads. The effects of E2 on the expression of PSD95 and the spine density disappeared when the dentate gyrus (DG) had been excised at 1 day in vitro (DIV). FM1-43 analysis of subregional hippocampal neuron cultures which were comprised of Ammon's horn neurons, DG neurons, or a mixture of these neurons, revealed that E2 increased the number of presynaptic sites in the cultures that contained DG neurons. K252a, a potent inhibitor of the high affinity receptor of brain-derived neurotrophic factor (BDNF), and function-blocking antibody to BDNF (BDNFAB) completely inhibited the effects of E2 in hippocampal slice cultures and subregional neuron cultures, whereas ICI182,780 (ICI), a strong antagonist of nuclear estrogen receptors (nERs), did not. Expression of BDNF in DG neurons was markedly higher than that in Ammon's horn neurons and E2 did not affect these expression levels. E2 significantly increased the BDNF release from DG neurons. KT5720, a specific inhibitor of 3'-5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA), and Rp-adenosine 3', 5'-cyclic monophosphorothioate triethylammonium salt (Rp-cAMP), a non-hydrolyzable diastereoisomer and a potent inhibitor of PKA, completely suppressed the E2-induced increase in BDNF release, whereas ICI and U0126, a potent inhibitor of MAP kinase kinase (MEK), did not. These results suggest that E2 induces synaptogenesis between mossy fibers and CA3 neurons by enhancing BDNF release from DG granule cells in a nER-independent and PKA-dependent manner.
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Affiliation(s)
- Kaoru Sato
- Division of Pharmacology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
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Abstract
Hormonal ligands for the nuclear receptor superfamily have at least two interacting mechanisms of action: 1) classical transcriptional regulation of target genes (genomic mechanisms); and 2) nongenomic actions that are initiated at the cell membrane, which could impact transcription. Although transcriptional mechanisms are increasingly well understood, membrane-initiated actions of these ligands are incompletely understood. Historically, this has led to a considerable divergence of thought in the molecular endocrine field. We have attempted to uncover principles of hormone action that are relevant to membrane-initiated actions of estrogens. There is evidence that the membrane-limited actions of hormones, particularly estrogens, involve the rapid activation of kinases and the release of calcium. Membrane actions of estrogens, which activate these rapid signaling cascades, can also potentiate nuclear transcription. These signaling cascades may occur in parallel or in series but subsequently converge at the level of modification of transcriptionally relevant molecules such as nuclear receptors and/or coactivators. In addition, other hormones or neurotransmitters may also activate cascades to crosstalk with estrogen receptor-mediated transcription. The idea of synergistic coupling between membrane-initiated and genomic actions of hormones fundamentally revises the paradigms of cell signaling in neuroendocrinology.
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Affiliation(s)
- Nandini Vasudevan
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Huddleston GG, Paisley JC, Graham S, Grober MS, Clancy AN. Implants of estradiol conjugated to bovine serum albumin in the male rat medial preoptic area promote copulatory behavior. Neuroendocrinology 2007; 86:249-59. [PMID: 17726305 DOI: 10.1159/000107695] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Accepted: 07/06/2007] [Indexed: 12/26/2022]
Abstract
The expression of mating behavior in male rats is dependent on estrogen-responsive neurons in the medial preoptic area (MPO). Previous reports showed that mating is attenuated if the aromatization of testosterone to estradiol (E2) is blocked in the MPO and that mating is maintained by MPO E2 implants. However, the mechanisms by which E2 exerts its action are not fully understood. It had been thought that E2 acted exclusively by binding to nuclear estrogen receptors to exert it effects; however, recent reports suggest that E2 also binds to membrane-associated receptors activating downstream intracellular cascade responses. In this study, we aimed to determine if an action of E2 at the cell surface is sufficient to support mating behavior. Therefore, either vehicle, E2, or E2 conjugated to bovine serum albumin (BSA-E2: a complex of E2 and a large protein that will not cross the plasma membrane, thereby restricting the action of E2 to cell surface signaling) was chronically administered bilaterally to the MPO of castrated, dihydrotestosterone-treated male rats. Mating behavior was supported by MPO BSA-E2 implants, suggesting that E2 operates in the MPO via a cell surface mechanism to facilitate male rat mating behavior.
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Affiliation(s)
- Gloria G Huddleston
- Department of Biology, Georgia State University, Atlanta, GA 30302-4010, USA
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Yao X, Chen H, Ohtake N, Shoumura S. Morphological alterations in the growth plate cartilage of ovariectomized mice. Med Mol Morphol 2006; 39:193-7. [PMID: 17187181 DOI: 10.1007/s00795-006-0336-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 08/14/2006] [Indexed: 12/01/2022]
Abstract
The effects of ovariectomy on growth and estrogen receptor (ER) expression level in the epiphyseal growth plate in mice have been estimated by histomorphometry and immunohistochemistry. Twelve female ddY mice, 8-9 weeks of age, were subjected to bilateral ovariectomy and 12 others were sham operated. They were then killed 8 weeks later. Ovariectomy significantly increased the total thickness of the distal femoral and proximal tibial growth plate cartilage. Ovariectomy caused a 1.4-fold increase in the thickness of the proliferative layer in the distal growth plate of the femur and a 1.3-fold increase in the thickness of the proliferative layer in the proximal growth plate of the tibia. ERalpha and ERbeta immunoreactivity was detected in chondrocytes of the growth plate and the expression level of ERs in epiphyseal plates was increased in ovariectomized mice compared with controls. These data suggest that ERalpha and ERbeta are coexpressed in the growth plates of the mice and that the cartilage growth and the level of expression of ERs in these tissues are hormonally regulated.
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Affiliation(s)
- Xianfeng Yao
- Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
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Wang R, Zhang QG, Han D, Xu J, Lü Q, Zhang GY. Inhibition of MLK3-MKK4/7-JNK1/2 pathway by Akt1 in exogenous estrogen-induced neuroprotection against transient global cerebral ischemia by a non-genomic mechanism in male rats. J Neurochem 2006; 99:1543-54. [PMID: 17064355 DOI: 10.1111/j.1471-4159.2006.04201.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Numerous studies have demonstrated the neuroprotective effects of estrogen in experimental cerebral ischemia. To investigate molecular mechanisms of estrogen neuroprotection in global ischemia, immunoblotting, immunohistochemistry and Nissel-staining analysis were used. Our results showed that chronic pretreatment with beta-estradiol 3-benzoate (E2) enhanced Akt1 activation and reduced the activation of mixed-lineage kinase 3 (MLK3), mitogen-activated protein kinase kinase 4/7 (MKK4/7), and c-Jun N-terminal kinase 1/2 (JNK1/2) in the hippocampal CA1 subfield during reperfusion after 15 min of global ischemia. In addition, E2 reduced downstream JNK nuclear and non-nuclear components, c-Jun and Bcl-2 phosphorylation and Fas ligand protein expression induced by ischemia/reperfusion. Administration of phosphoinositide 3-kinase (PI3K) inhibitor LY 294,002 prevented both activation of Akt1 and inhibition of MLK3, MKK4/7 and JNK1/2. The interaction between ERalpha and the p85 subunit of PI3K was also examined. E2 and antiestrogen ICI 182,780 promoted and prevented this interaction, respectively. Furthermore, ICI 182,780 blocked both the activation of Akt1 and the inhibition of MLK3, MKK4/7 and JNK1/2. Photomicrographs of cresyl violet-stained brain sections showed that E2 reduced CA1 neuron loss after 5 days of reperfusion, which was abolished by ICI 182,780 and LY 294,002. Our data indicate that in response to estrogen, ERalpha interacts with PI3K to activate Akt1, which may inhibit the MLK3-MKK4/7-JNK1/2 pathway to protect hippocampal CA1 neurons against global cerebral ischemia in male rats.
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Affiliation(s)
- Ran Wang
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory for Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou, China
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Abstract
Starting from fetal life, estrogens are crucial in determining central gender dimorphism, and an estrogen-induced synaptic plasticity is well evident during puberty and seasonal changes as well as during the ovarian cycle. Estrogens act on the central nervous system (CNS) both through genomic mechanisms, modulating synthesis, release and metabolism of neurotransmitters, neuropeptides and neurosteroids, and through non-genomic mechanisms, influencing electrical excitability, synaptic function and morphological features. Therefore, estrogen's neuroactive effects are multifaceted and encompass a system that ranges from the chemical to the biochemical to the genomic mechanisms, protecting against a wide range of neurotoxic insults. Clinical evidences show that, during the climacteric period, estrogen withdrawal in the limbic system gives rise to modifications in mood, behaviour and cognition and that estrogen administration is able to improve mood and cognitive efficiency in post-menopause. Many biological mechanisms support the hypothesis that estrogens might protect against Alzheimer's disease (AD) by influencing neurotransmission, increasing cerebral blood flow, modulating growth proteins associated with axonal elongation and blunting the neurotoxic effects of beta-amyloid. On the contrary, clinical studies of estrogen replacement therapy (ERT) and cognitive function have reported controversial results, indicating a lack of efficacy of estrogens on cognition in post-menopausal women aged >or=65 years. These findings suggest the presence of a critical period for HRT-related neuroprotection and underlie the potential importance of early initiation of therapy for cognitive benefit. In this review, we shall first describe the multiple effects of steroids in the nervous system, which may be significant in the ageing process. A critical update of HRT use in women and a discussion of possible prospectives for steroid use are subsequently proposed.
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Affiliation(s)
- Andrea Riccardo Genazzani
- Department of Reproductive Medicine and Child Development, Division of Obstetrics and Gynecology, University of Pisa, Pisa, Italy.
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Bryant DN, Sheldahl LC, Marriott LK, Shapiro RA, Dorsa DM. Multiple pathways transmit neuroprotective effects of gonadal steroids. Endocrine 2006; 29:199-207. [PMID: 16785596 DOI: 10.1385/endo:29:2:199] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 11/30/1999] [Accepted: 10/25/2005] [Indexed: 12/27/2022]
Abstract
Numerous preclinical studies suggest that gonadal steroids, particularly estrogen, may be neuroprotective against insult or disease progression. This paper reviews the mechanisms contributing to estrogen-mediated neuroprotection. Rapid signaling pathways, such as MAPK, PI3K, Akt, and PKC, are required for estrogen's ability to provide neuroprotection. These rapid signaling pathways converge on genomic pathways to modulate transcription of E2-responsive genes via ERE-dependent and ERE-independent mechanisms. It is clear that both rapid signaling and transcription are important for estrogen's neuroprotective effects. A mechanistic understanding of estrogen-mediated neuroprotection is crucial for the development of therapeutic interventions that enhance quality of life without deleterious side effects.
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Affiliation(s)
- Damani N Bryant
- Department of Physiology and Pharmacology (L334), Oregon Health & Science University, Portland, OR 97239, USA
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Bereiter DA, Cioffi JL, Bereiter DF. Oestrogen receptor-immunoreactive neurons in the trigeminal sensory system of male and cycling female rats. Arch Oral Biol 2006; 50:971-9. [PMID: 15893734 DOI: 10.1016/j.archoralbio.2005.03.010] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 03/04/2005] [Indexed: 12/31/2022]
Abstract
Many common craniofacial pain conditions are more prevalent in women than men and may be related to the phase of the menstrual cycle. Long-term effects of oestrogen in the nervous system are produced by receptor-mediated [oestrogen receptor alpha (ERalpha) and beta (ERbeta) isoforms] mechanisms; however, it is not known if the distribution of ER-positive neurons in the trigeminal system is similar in males and females. Quantitative immunocytochemistry was used to compare the distribution of ERalpha-labelled neurons in the trigeminal brainstem complex (TBC) and ganglion of male and female rats at different stages of the oestrous cycle. A high density of ERalpha-labelled neurons was seen in the superficial laminae (I-III) throughout the trigeminal subnucleus caudalis (Vc) and the upper cervical dorsal horn. Counts of ERalpha-positive neurons in laminae I-III were similar for prooestrous and dioestrous females, while males had fewer cells. The deeper laminae (IV-V) of the Vc and the cervical dorsal horn had few ERalpha-positive neurons in all groups. At the region surrounding the central canal at caudal levels of the Vc, prooestrous females had more ERalpha-positive neurons than dioestrous females or males. Few labelled cells were seen rostral to the trigeminal subnucleus interpolaris/caudalis transition region (Vi/Vc) in any group. In the trigeminal ganglion, prooestrous and dioestrous females had a moderate (8-10%) number of nuclear-labelled small or medium-sized neurons, while males had fewer labelled cells (4.5%). Qualitatively, the pattern of staining for ERbeta was similar, although weaker, than for ERalpha in the trigeminal dorsal horn or ganglion. These results were consistent with the hypothesis that oestrogen acts through trigeminal ganglion cells and caudal portions of the Vc to modulate sensory and autonomic aspects of craniofacial pain in a sex-related manner.
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Affiliation(s)
- D A Bereiter
- Department of Surgery, Rhode Island Hospital/Brown Medical School, 593 Eddy Street 222 Nursing Arts, Providence, RI 02903, USA.
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Abstract
Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens clearly have a key role in skin aging homeostasis as evidenced by the accelerated decline in skin appearance seen in the perimenopausal years. Estrogens improve skin in many ways. Among these, they increase collagen content and skin thickness and improve skin moisture. However, despite the knowledge that estrogens have such important effects on skin, the cellular and subcellular sites and mechanisms of estrogen action are still poorly understood. Estrogen receptors (ERs) have been detected in skin, and recent studies suggest that estrogens exert their effect in skin through the same molecular pathways used in other non-reproductive tissues. Although systemic hormone replacement therapy (HRT) has been used for many years, recent trials have reported a significant increased risk of breast cancer and other pathologies with this treatment. This has led to reconsider the risks and benefits of HRT. For this reason, systemic HRT cannot be recommended today to treat skin aging. Currently, intensive research is conducted to develop new drugs called selective ER modulators (SERMs). These drugs exert mixed estrogenic and antiestrogenic effects depending on the tissue and cell type. One might expect in the future such a drug targeting specifically the skin without systemic side effects.
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Mehra RD, Sharma K, Nyakas C, Vij U. Estrogen receptor alpha and beta immunoreactive neurons in normal adult and aged female rat hippocampus: a qualitative and quantitative study. Brain Res 2005; 1056:22-35. [PMID: 16122717 DOI: 10.1016/j.brainres.2005.06.073] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 06/28/2005] [Accepted: 06/29/2005] [Indexed: 11/21/2022]
Abstract
We have studied the distribution pattern and levels of expression of two estrogen receptor (ER) subtypes, ERalpha and ERbeta, in the normal adult (n = 10) and the aged (n = 10) female rat hippocampus with the objective to establish baseline data and the changes that occur during aging. Techniques including immunohistochemical localization, co-localization with double immunofluorescence and confocal microscopy, image analysis including neuronal counts/mm(2) area and measurements of optical density (OD) of immunoreactivity in immunoreactive neurons and Western blot analysis have been used. The results revealed ERalpha and ERbeta positive neurons in all subfields of the hippocampus with maximum presence in the stratum pyramidale of CA3. Some stained neurons in CA3 exhibited pyramidal neuron like morphological characteristics; such neurons were not found in CA1. All other immunoreactive neurons showed non-pyramidal neuron like morphological characteristics. Neuronal counts revealed a significant decrease in the number of immunoreactive neurons in CA3-CA1 of aged hippocampus. The percent decrease in counts of the immunoreactive neurons/mm(2) area in the aged rat (compared to the adult) was 78% for the ERalpha and 88% for the ERbeta (P < 0.001) in CA3. In CA1, it was 56% (P < 0.001) and 41% (P < 0.01) respectively. The OD of immunoreactivity was significantly decreased (P < 0.01) in CA3 but increased (P < 0.01) in the CA1 immunoreactive neurons. Western blot analysis also showed a significant decline (P < 0.01) in the levels of the ERalpha and ERbeta proteins in the aged hippocampus. Co-localization revealed that the two ER subtypes do co-exist in the same hippocampal neurons.
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Affiliation(s)
- Raj D Mehra
- Department of Anatomy, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India.
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46
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Viso-León MC, Ripoll C, Nadal A. Oestradiol rapidly inhibits Ca2+ signals in ciliary neurons through classical oestrogen receptors in cytoplasm. Pflugers Arch 2005; 449:33-41. [PMID: 15258764 DOI: 10.1007/s00424-004-1308-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Oestrogen plays a key role in a great variety of actions in the nervous system, either through classical or alternative pathways. The classical pathways are initiated after oestrogen binding to the oestrogen receptors ERalpha or ERbeta, which translocate from the cytoplasm to the nucleus and act there as transcription factors. Alternative pathways are initiated at the plasma membrane and cytoplasm, via binding to classical or non-classical ERs. Using isolated ciliary ganglion neurons from the chick embryo and Ca2+ imaging, we demonstrated that a 10-min exposure to 17beta-oestradiol reduces Ca2+ influx through the plasma membrane. This effect was not reproduced by oestradiol conjugated to bovine serum albumin, which does not cross the plasma membrane, indicating that 17beta-oestradiol was acting intracellularly. ERalpha was detected in the cytoplasm by immunostaining and its involvement in the regulation of Ca2+ influx by ICI182,780 inhibition. The phosphatidylinositol-3 kinase (Pi3-kinase) inhibitor wortmannin and the nitric oxide synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME) both blocked the oestradiol effect. The oestradiol effect was reproduced by 8Br-cGMP and abolished in the presence of the cGMP-dependent protein kinase (PKG) inhibitor KT5823. Our study indicates that 17beta-oestradiol can regulate Ca2+ influx via PI3-kinase, NOS and PKG after activation of cytoplasmic ER.
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Affiliation(s)
- M Carmen Viso-León
- Institut de Bioenginyeria, Universitat Miguel Hernández d'Elx, Campus de Sant Joan, Carretera Alacant-Valéncia Km 87, 03550 Sant Joan d'Alacant, Spain
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Kalita K, Szymczak S, Kaczmarek L. Non-nuclear estrogen receptor beta and alpha in the hippocampus of male and female rats. Hippocampus 2005; 15:404-12. [PMID: 15669092 DOI: 10.1002/hipo.20066] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Estrogens play important roles in the brain, acting through two receptor types, ERalpha and ERbeta, both recognized as transcription factors. In this study, we investigated the ERbeta mRNA and protein expression in the male and female rat brain, focusing on the hippocampus, and comparing with well-known ERalpha expression patterns. Extranuclear ERbeta localization, as shown by light microscopic immunocytochemistry and tissue fractionation experiments, was noted in the hippocampus, whereas nuclear ERbeta was present in the amygdala. Despite these marked differences in subcellular localizations, similar expression levels of ERbeta proteins as well as the profile of ERbeta mRNA isoforms were observed in the two brain structures. ERalpha was localized to the nucleus more so than ERbeta, yet not without an extranuclear component. Our results suggest that cytoplasmic estrogen receptors may play an important role in hippocampal physiology.
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Affiliation(s)
- Katarzyna Kalita
- Department of Molecular and Cellular Neurobiology, Nencki Institute, Warsaw, Poland
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Cordey M, Pike CJ. Neuroprotective properties of selective estrogen receptor agonists in cultured neurons. Brain Res 2005; 1045:217-23. [PMID: 15910780 DOI: 10.1016/j.brainres.2005.03.032] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Revised: 03/12/2005] [Accepted: 03/15/2005] [Indexed: 11/21/2022]
Abstract
To investigate the role of the estrogen receptor (ER) in mediating neuroprotection, the neuroprotective profiles of selective ER agonists for ERalpha and ERbeta, propylpyrazole triol (PPT) and 2,3-bis(4-hydroxyphenyl) proprionitrile (DPN), respectively, were compared to that of 17beta-estradiol and 17alpha-estradiol in primary neuron cultures challenged by beta-amyloid toxicity. All compounds were found to be neuroprotective in an ER-dependent manner. However, protein kinase C (PKC) inhibition completely blocked the protective effects of 17beta-estradiol and 17alpha-estradiol and significantly attenuated PPT but not DPN neuroprotection. These data indicate that estrogen-mediated neuroprotection likely involves a variety of mechanisms and that protection due to PKC activation is more likely due to ERalpha compared to ERbeta.
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Affiliation(s)
- Myriam Cordey
- Neuroscience Graduate Program and Andrus Gerontology Center, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089-0191, USA
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Fried G, Andersson E, Csöregh L, Enmark E, Gustafsson JA, Aanesen A, Osterlund C. Estrogen receptor beta is expressed in human embryonic brain cells and is regulated by 17beta-estradiol. Eur J Neurosci 2005; 20:2345-54. [PMID: 15525276 DOI: 10.1111/j.1460-9568.2004.03693.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to study estrogen effects on developing human neurons, we have established primary cultures of neurons and glia from 8-13-week human embryo cortex and spinal cord. The neuronal identity of the cultures was verified using the neuronal synaptic vesicle and neuronal endosomal membrane markers synaptotagmin, synapsin and synaptophysin, and the glial contribution to the mixed glial-neuronal cultures was verified using the glial marker glial fibrillary acidic protein (GFAP). We here report expression of estrogen receptor beta (ERbeta) in these cells using RT-PCR and sequencing, RNAse protection assay, immunohistochemistry and immunoblotting. We found that both neuronal and mixed glial-neuronal cultures expressed ERbeta. Treatment with 17beta-estradiol gave an increased expression of ERbeta in both types of cultures. These results suggest that ERbeta is expressed in fetal brain and thus may mediate effects of estrogen in the developing nervous system. Furthermore, the results suggest that expression of ERbeta in fetal brain may be regulated by estrogen.
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Affiliation(s)
- G Fried
- Department of Woman and Child Health, Karolinska Institute, Division of Obstetrics and Gynecology, S-171-76 Stockholm, Sweden.
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Huang Y, Huang YL, Zhang S, Zhu YC, Yao T. Estradiol acutely attenuates glutamate-induced calcium overload in primarily cultured rat hippocampal neurons through a membrane receptor-dependent mechanism. Brain Res 2005; 1026:254-60. [PMID: 15488487 DOI: 10.1016/j.brainres.2004.08.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2004] [Indexed: 11/21/2022]
Abstract
Increasing lines of evidence indicate that estrogen acts as a neuroprotective agent through a nongenomic mechanism. We tested the hypothesis that 17beta-estradiol could rapidly attenuate glutamate-induced calcium (Ca2+) overload in rat primary hippocampal neurons via a membrane receptor-dependent mechanism. The bulk cytosolic intracellular Ca2+ level was measured in neurons with fluorescent Ca2+ probe fluo3. Preexposure of primary cultured hippocampal neurons to 17beta-estradiol for 3 min attenuated intracellular Ca2+ increase induced by glutamate in a concentration-dependent manner. The action of 17beta-estradiol was reversible after washout. Administration of membrane-impermeable 17beta-estradiol conjugated to bovine serum albumin (E2-BSA) produced the same effect, suggesting possible involvement of cell membrane receptors. ICI 182,780, a specific estrogen receptor (ER) antagonist, blocked the neuronal response to 17beta-estradiol and estradiol BSA, indicating a role of specific ERs. The present study demonstrates that 17beta-estradiol acutely reduces glutamate-stimulated intracellular Ca2+ increase via ERs probably on the cell surface of the hippocampal neurons.
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Affiliation(s)
- Ying Huang
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032, People's Republic of China
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