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Bárez-López S, Konopacka A, Cross SJ, Greenwood M, Skarveli M, Murphy D, Greenwood MP. Transcriptional and Post-Transcriptional Regulation of Oxytocin and Vasopressin Gene Expression by CREB3L1 and CAPRIN2. Neuroendocrinology 2022; 112:1058-1077. [PMID: 35051932 DOI: 10.1159/000522088] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/06/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Water homoeostasis is achieved by secretion of the peptide hormones arginine vasopressin (AVP) and oxytocin (OXT) that are synthesized by separate populations of magnocellular neurones (MCNs) in the supraoptic and paraventricular (PVN) nuclei of the hypothalamus. To further understand the molecular mechanisms that facilitate biosynthesis of AVP and OXT by MCNs, we have explored the spatiotemporal dynamic, both mRNA and protein expression, of two genes identified by our group as being important components of the osmotic defence response: Caprin2 and Creb3l1. METHODS By RNA in situ hybridization and immunohistochemistry, we have characterized the expression of Caprin2 and Creb3l1 in MCNs in the basal state, in response to dehydration, and during rehydration in the rat. RESULTS We found that Caprin2 and Creb3l1 are expressed in AVP and OXT MCNs and in response to dehydration expression increases in both MCN populations. Protein levels mirror the increase in transcript levels for both CREB3L1 and CAPRIN2. In view of increased CREB3L1 and CAPRIN2 expression in OXT neurones by dehydration, we explored OXT-specific functions for these genes. By luciferase assays, we demonstrate that CREB3L1 may be a transcription factor regulating Oxt gene expression. By RNA immunoprecipitation assays and Northern blot analysis of Oxt mRNA poly(A) tails, we have found that CAPRIN2 binds to Oxt mRNA and regulates its poly(A) tail length. Moreover, in response to dehydration, Caprin2 mRNA is subjected to nuclear retention, possibly to regulate Caprin2 mRNA availability in the cytoplasm. CONCLUSION The exploration of the spatiotemporal dynamics of Creb3l1- and Caprin2-encoded mRNAs and proteins has provided novel insights beyond the AVP-ergic system, revealing novel OXT-ergic system roles of these genes in the osmotic defence response.
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Affiliation(s)
- Soledad Bárez-López
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
| | - Agnieszka Konopacka
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
| | - Stephen J Cross
- Wolfson Bioimaging Facility, Biomedical Sciences Building, University of Bristol, Bristol, UK
| | - Mingkwan Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
| | - Marina Skarveli
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
| | - David Murphy
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
| | - Michael P Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, UK
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Pauža AG, Mecawi AS, Paterson A, Hindmarch CCT, Greenwood M, Murphy D, Greenwood MP. Osmoregulation of the transcriptome of the hypothalamic supraoptic nucleus: A resource for the community. J Neuroendocrinol 2021; 33:e13007. [PMID: 34297454 DOI: 10.1111/jne.13007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/25/2021] [Accepted: 06/20/2021] [Indexed: 01/13/2023]
Abstract
The hypothalamic supraoptic nucleus (SON) is a core osmoregulatory control centre that deciphers information about the metabolic state of the organism and orchestrates appropriate homeostatic (endocrine) and allostatic (behavioural) responses. We have used RNA sequencing to describe the polyadenylated transcriptome of the SON of the male Wistar Han rat. These data have been mined to generate comprehensive catalogues of functional classes of genes (enzymes, transcription factors, endogenous peptides, G protein coupled receptors, transporters, catalytic receptors, channels and other pharmacological targets) expressed in this nucleus in the euhydrated state, and that together form the basal substrate for its physiological interactions. We have gone on to show that fluid deprivation for 3 days (dehydration) results in changes in the expression levels of 2247 RNA transcripts, which have similarly been functionally catalogued, and further mined to describe enriched gene categories and putative regulatory networks (Regulons) that may have physiological importance in SON function related plasticity. We hope that the revelation of these genes, pathways and networks, most of which have no characterised roles in the SON, will encourage the neuroendocrine community to pursue new investigations into the new 'known-unknowns' reported in the present study.
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Affiliation(s)
- Audrys G Pauža
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, University of Bristol, Bristol, UK
| | - André Souza Mecawi
- Laboratory of Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Alex Paterson
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, University of Bristol, Bristol, UK
- Bristol Genomics Facility, University of Bristol, Bristol, UK
| | - Charles C T Hindmarch
- Queen's Cardiopulmonary Unit (QCPU), Department of Medicine, Translational Institute of Medicine (TIME), Queen's University, Kingston, ON, Canada
| | - Mingkwan Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, University of Bristol, Bristol, UK
| | - David Murphy
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, University of Bristol, Bristol, UK
| | - Michael P Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, University of Bristol, Bristol, UK
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Greenwood M, Paterson A, Rahman PA, Gillard BT, Langley S, Iwasaki Y, Murphy D, Greenwood MP. Transcription factor Creb3l1 regulates the synthesis of prohormone convertase enzyme PC1/3 in endocrine cells. J Neuroendocrinol 2020; 32:e12851. [PMID: 32319174 PMCID: PMC7359860 DOI: 10.1111/jne.12851] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/31/2020] [Accepted: 03/31/2020] [Indexed: 12/23/2022]
Abstract
Transcription factor cAMP responsive element-binding protein 3 like 1 (Creb3l1) is a non-classical endoplasmic reticulum stress molecule that is emerging as an important component for cellular homeostasis, particularly within cell types with high peptide secretory capabilities. We have previously shown that Creb3l1 serves an important role in body fluid homeostasis through its transcriptional control of the gene coding for antidiuretic hormone arginine vasopressin in the neuropeptide-rich magnocellular neurones of the supraoptic nucleus. In response to osmotic stimuli such as dehydration, vasopressin magnocellular neurones undergo remarkable transcriptome changes, including increased Creb3l1 expression, to ensure that the supply of vasopressin meets demand. To determine where else Creb3l1 fits into the secretory cell supply chain, we performed RNA-sequencing of Creb3l1 knockdown anterior pituitary mouse corticotroph cell line AtT20. The target chosen for further investigation was Pcsk1, which encodes proprotein convertase enzyme 1 (PC1/3). PC1/3 is crucial for processing of neuropeptides and peptide hormones such as pro-opiomelanocortin (POMC), proinsulin, proglucagon, vasopressin and oxytocin. Viral manipulations in supraoptic nuclei by over-expression of Creb3l1 increased Pcsk1, whereas Creb3l1 knockdown decreased Pcsk1 expression. In vitro promoter activity and binding studies showed that Creb3l1 was a transcription factor of the Pcsk1 gene binding directly to a G-box motif in the promoter. In the dehydrated rat anterior pituitary, Creb3l1 and Pcsk1 expression decreased in parallel compared to control, supporting our findings from manipulations in AtT20 cells and the supraoptic nucleus. No relationship was observed between Creb3l1 and Pcsk1 expression in the neurointermediate lobe of the pituitary, indicating a different mechanism of PC1/3 synthesis by these POMC-synthesising cells. Therefore, Creb3l1, by regulating the expression of Pcsk1, does not control the processing of POMC peptides in the intermediate lobe.
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Affiliation(s)
- Mingkwan Greenwood
- Translational Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
| | - Alex Paterson
- Translational Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
| | | | | | - Sydney Langley
- Translational Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
| | | | - David Murphy
- Translational Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
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Khan AM, Grant AH, Martinez A, Burns GAPC, Thatcher BS, Anekonda VT, Thompson BW, Roberts ZS, Moralejo DH, Blevins JE. Mapping Molecular Datasets Back to the Brain Regions They are Extracted from: Remembering the Native Countries of Hypothalamic Expatriates and Refugees. ADVANCES IN NEUROBIOLOGY 2018; 21:101-193. [PMID: 30334222 PMCID: PMC6310046 DOI: 10.1007/978-3-319-94593-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article focuses on approaches to link transcriptomic, proteomic, and peptidomic datasets mined from brain tissue to the original locations within the brain that they are derived from using digital atlas mapping techniques. We use, as an example, the transcriptomic, proteomic and peptidomic analyses conducted in the mammalian hypothalamus. Following a brief historical overview, we highlight studies that have mined biochemical and molecular information from the hypothalamus and then lay out a strategy for how these data can be linked spatially to the mapped locations in a canonical brain atlas where the data come from, thereby allowing researchers to integrate these data with other datasets across multiple scales. A key methodology that enables atlas-based mapping of extracted datasets-laser-capture microdissection-is discussed in detail, with a view of how this technology is a bridge between systems biology and systems neuroscience.
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Affiliation(s)
- Arshad M Khan
- UTEP Systems Neuroscience Laboratory, University of Texas at El Paso, El Paso, TX, USA.
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA.
- Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, USA.
| | - Alice H Grant
- UTEP Systems Neuroscience Laboratory, University of Texas at El Paso, El Paso, TX, USA
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
- Graduate Program in Pathobiology, University of Texas at El Paso, El Paso, TX, USA
| | - Anais Martinez
- UTEP Systems Neuroscience Laboratory, University of Texas at El Paso, El Paso, TX, USA
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
- Graduate Program in Pathobiology, University of Texas at El Paso, El Paso, TX, USA
| | - Gully A P C Burns
- Information Sciences Institute, Viterbi School of Engineering, University of Southern California, Marina del Rey, CA, USA
| | - Brendan S Thatcher
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Vishwanath T Anekonda
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Benjamin W Thompson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Zachary S Roberts
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Daniel H Moralejo
- Division of Neonatology, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, USA
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Greenwood MP, Greenwood M, Gillard BT, Chitra Devi R, Murphy D. Regulation of cAMP Responsive Element Binding Protein 3-Like 1 (Creb3l1) Expression by Orphan Nuclear Receptor Nr4a1. Front Mol Neurosci 2017; 10:413. [PMID: 29311806 PMCID: PMC5732970 DOI: 10.3389/fnmol.2017.00413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/28/2017] [Indexed: 12/28/2022] Open
Abstract
Cyclic AMP (cAMP) inducible transcription factor cAMP responsive element binding protein 3 like 1 (Creb3l1) is strongly activated in the hypothalamus in response to hyperosmotic cues such as dehydration (DH). We have recently shown that Creb3l1 expression is upregulated by cAMP pathways in vitro, however the exact mechanisms are not known. Here we show that increasing Creb3l1 transcription by raising cAMP levels in mouse pituitary AtT20 cells automatically initiates cleavage of Creb3l1, leading to a greater abundance of the transcriptionally active N-terminal portion. Inhibiting protein synthesis indicated that de novo protein synthesis of an intermediary transcription factor was required for Creb3l1 induction. Strategic mining of our microarray data from dehydrated rodent hypothalamus revealed four candidates, reduced to two by analysis of acute hyperosmotic-induced transcriptional activation profiles in the hypothalamus, and one, orphan nuclear receptor Nr4a1, by direct shRNA mediated silencing in AtT20 cells. We show that activation of Creb3l1 transcription by Nr4a1 involves interaction with a single NBRE site in the promoter region. The ability to activate Creb3l1 transcription by this pathway in vitro is dictated by the level of methylation of a CpG island within the proximal promoter/5′UTR of this gene. We thus identify a novel cAMP-Nr4a1-Creb3l1 transcriptional pathway in AtT20 cells and also, our evidence would suggest, in the hypothalamus.
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Affiliation(s)
| | - Mingkwan Greenwood
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Benjamin T Gillard
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - R Chitra Devi
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - David Murphy
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.,Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Wang ZP, Wang D, Wang CL, Xie WJ, Zhu YF, Chen XW. Transcriptome characterization of HPG axis from Chinese sea perch Lateolabrax maculatus. JOURNAL OF FISH BIOLOGY 2017; 91:1407-1418. [PMID: 28913865 DOI: 10.1111/jfb.13459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
Here the transcriptome and differential gene expression in the adult brain and gonads of the Chinese sea perch Lateolabrax maculatus were reported. A total of 78 256 909 clean reads were generated from the adult brain, ovary and testis by using the Illumina HiSeq2000 platform and assembled into 274 909 contigs. A total of 31 683 unigenes were annotated based on sequence similarity and 20 702 unigenes were found to exhibit 8237 gene ontology terms and 3888 signal pathways. Transcripts of 26 623 unigenes were present in all of the tissues, whereas pairwise comparisons revealed that 671/367, 496/315 and 1668/580 unigenes were up-down regulated by at least two-fold between the brain and ovary, ovary and testis and brain and testis, respectively. Homology search led to the identification of reproduction-associated genes of the brain-gonad axis, including those involved in sex differentiation and maintenance. The data provided an integrated and comprehensive transcriptome resource for L. maculatus, which could be used for further research on hypothalamus-pituitary-gonad axis gene function, reproduction regulation and sex-biased gene expression.
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Affiliation(s)
- Z P Wang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - D Wang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - C L Wang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - W J Xie
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Y F Zhu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - X W Chen
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
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Song 宋志林 Z, Roncal-Jimenez CA, Lanaspa-Garcia MA, Oppelt SA, Kuwabara M, Jensen T, Milagres T, Andres-Hernando A, Ishimoto T, Garcia GE, Johnson G, MacLean PS, Sanchez-Lozada LG, Tolan DR, Johnson RJ. Role of fructose and fructokinase in acute dehydration-induced vasopressin gene expression and secretion in mice. J Neurophysiol 2016; 117:646-654. [PMID: 27852737 DOI: 10.1152/jn.00781.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/10/2016] [Indexed: 12/13/2022] Open
Abstract
Fructose stimulates vasopressin in humans and can be generated endogenously by activation of the polyol pathway with hyperosmolarity. We hypothesized that fructose metabolism in the hypothalamus might partly control vasopressin responses after acute dehydration. Wild-type and fructokinase-knockout mice were deprived of water for 24 h. The supraoptic nucleus was evaluated for vasopressin and markers of the aldose reductase-fructokinase pathway. The posterior pituitary vasopressin and serum copeptin levels were examined. Hypothalamic explants were evaluated for vasopressin secretion in response to exogenous fructose. Water restriction increased serum and urine osmolality and serum copeptin in both groups of mice, although the increase in copeptin in wild-type mice was larger than that in fructokinase-knockout mice. Water-restricted, wild-type mice showed an increase in vasopressin and aldose reductase mRNA, sorbitol, fructose and uric acid in the supraoptic nucleus. In contrast, fructokinase-knockout mice showed no change in vasopressin or aldose reductase mRNA, and no changes in sorbitol or uric acid, although fructose levels increased. With water restriction, vasopressin in the pituitary of wild-type mice was significantly less than that of fructokinase-knockout mice, indicating that fructokinase-driven vasopressin secretion overrode synthesis. Fructose increased vasopressin release in hypothalamic explants that was not observed in fructokinase-knockout mice. In situ hybridization documented fructokinase mRNA in the supraoptic nucleus, paraventricular nucleus and suprachiasmatic nucleus. Acute dehydration activates the aldose reductase-fructokinase pathway in the hypothalamus and partly drives the vasopressin response. Exogenous fructose increases vasopressin release in hypothalamic explants dependent on fructokinase. Nevertheless, circulating vasopressin is maintained and urinary concentrating is not impaired. NEW & NOTEWORTHY This study increases our understanding of the mechanisms leading to vasopressin release under conditions of water restriction (acute dehydration). Specifically, these studies suggest that the aldose reductase-fructokinase pathways may be involved in vasopressin synthesis in the hypothalamus and secretion by the pituitary in response to acute dehydration. Nevertheless, mice undergoing water restriction remain capable of maintaining sufficient vasopressin (copeptin) levels to allow normal urinary concentration. Further studies of the aldose reductase-fructokinase system in vasopressin regulation appear indicated.
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Affiliation(s)
- Zhilin Song 宋志林
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado; .,Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Carlos A Roncal-Jimenez
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Miguel A Lanaspa-Garcia
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Sarah A Oppelt
- Department of Biology, Boston University, Boston, Massachusetts
| | - Masanari Kuwabara
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Thomas Jensen
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado.,Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Tamara Milagres
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Ana Andres-Hernando
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Takuji Ishimoto
- Departments of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan; and
| | - Gabriela E Garcia
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Ginger Johnson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Paul S MacLean
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado, Aurora, Colorado
| | | | - Dean R Tolan
- Department of Biology, Boston University, Boston, Massachusetts
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
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Greenwood MP, Greenwood M, Mecawi AS, Antunes-Rodrigues J, Paton JFR, Murphy D. Rasd1, a small G protein with a big role in the hypothalamic response to neuronal activation. Mol Brain 2016; 9:1. [PMID: 26739966 PMCID: PMC4704412 DOI: 10.1186/s13041-015-0182-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/23/2015] [Indexed: 12/28/2022] Open
Abstract
Background Rasd1 is a member of the Ras family of monomeric G proteins that was first identified as a dexamethasone inducible gene in the pituitary corticotroph cell line AtT20. Using microarrays we previously identified increased Rasd1 mRNA expression in the rat supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus in response to increased plasma osmolality provoked by fluid deprivation and salt loading. RASD1 has been shown to inhibit adenylyl cyclase activity in vitro resulting in the inhibition of the cAMP-PKA-CREB signaling pathway. Therefore, we tested the hypothesis that RASD1 may inhibit cAMP stimulated gene expression in the brain. Results We show that Rasd1 is expressed in vasopressin neurons of the PVN and SON, within which mRNA levels are induced by hyperosmotic cues. Dexamethasone treatment of AtT20 cells decreased forskolin stimulation of c-Fos, Nr4a1 and phosphorylated CREB expression, effects that were mimicked by overexpression of Rasd1, and inhibited by knockdown of Rasd1. These effects were dependent upon isoprenylation, as both farnesyltransferase inhibitor FTI-277 and CAAX box deletion prevented Rasd1 inhibition of cAMP-induced gene expression. Injection of lentiviral vector into rat SON expressing Rasd1 diminished, whereas CAAX mutant increased, cAMP inducible genes in response to osmotic stress. Conclusions We have identified two mechanisms of Rasd1 induction in the hypothalamus, one by elevated glucocorticoids in response to stress, and one in response to increased plasma osmolality resulting from osmotic stress. We propose that the abundance of RASD1 in vasopressin expressing neurons, based on its inhibitory actions on CREB phosphorylation, is an important mechanism for controlling the transcriptional responses to stressors in both the PVN and SON. These effects likely occur through modulation of cAMP-PKA-CREB signaling pathway in the brain.
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Affiliation(s)
| | - Mingkwan Greenwood
- School of Clinical Sciences, University of Bristol, Bristol, BS1 3NY, UK.
| | - Andre S Mecawi
- School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil. .,Department of Physiology, University of Malaya, Kuala Lumpur, 50603, Malaysia. .,Department of Physiological Sciences, Biology Institute, Federal Rural University of Rio de Janeiro, Seropedica, Rio de Janeiro, Brazil.
| | | | - Julian F R Paton
- School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK.
| | - David Murphy
- School of Clinical Sciences, University of Bristol, Bristol, BS1 3NY, UK. .,Department of Physiology, University of Malaya, Kuala Lumpur, 50603, Malaysia.
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Greenwood MP, Greenwood M, Paton JFR, Murphy D. Control of Polyamine Biosynthesis by Antizyme Inhibitor 1 Is Important for Transcriptional Regulation of Arginine Vasopressin in the Male Rat Hypothalamus. Endocrinology 2015; 156:2905-17. [PMID: 25961839 PMCID: PMC4511134 DOI: 10.1210/en.2015-1074] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The polyamines spermidine and spermine are small cations present in all living cells. In the brain, these cations are particularly abundant in the neurons of the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus, which synthesize the neuropeptide hormones arginine vasopressin (AVP) and oxytocin. We recently reported increased mRNA expression of antizyme inhibitor 1 (Azin1), an important regulator of polyamine synthesis, in rat SON and PVN as a consequence of 3 days of dehydration. Here we show that AZIN1 protein is highly expressed in both AVP- and oxytocin-positive magnocellular neurons of the SON and PVN together with antizyme 1 (AZ1), ornithine decarboxylase, and polyamines. Azin1 mRNA expression increased in the SON and PVN as a consequence of dehydration, salt loading, and acute hypertonic stress. In organotypic hypothalamic cultures, addition of the irreversible ornithine decarboxylase inhibitor DL-2-(difluoromethyl)-ornithine hydrochloride significantly increased the abundance of heteronuclear AVP but not heteronuclear oxytocin. To identify the function of Azin1 in vivo, lentiviral vectors that either overexpress or knock down Azin1 were stereotaxically delivered into the SON and/or PVN. Azin1 short hairpin RNA delivery resulted in decreased plasma osmolality and had a significant effect on food intake. The expression of AVP mRNA was also significantly increased in the SON by Azin1 short hairpin RNA. In contrast, Azin1 overexpression in the SON decreased AVP mRNA expression. We have therefore identified AZIN1, and hence by inference, polyamines as novel regulators of the expression of the AVP gene.
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Affiliation(s)
- Michael P Greenwood
- School of Clinical Sciences (M.P.G., M.G., D.M.), University of Bristol, Bristol BS1 3NY, United Kingdom; School of Physiology and Pharmacology (J.F.R.P.), University of Bristol, Bristol BS8 1TD, United Kingdom; and Department of Physiology (D.M.), University of Malaya, Kuala Lumpur, Malaysia 50603
| | - Mingkwan Greenwood
- School of Clinical Sciences (M.P.G., M.G., D.M.), University of Bristol, Bristol BS1 3NY, United Kingdom; School of Physiology and Pharmacology (J.F.R.P.), University of Bristol, Bristol BS8 1TD, United Kingdom; and Department of Physiology (D.M.), University of Malaya, Kuala Lumpur, Malaysia 50603
| | - Julian F R Paton
- School of Clinical Sciences (M.P.G., M.G., D.M.), University of Bristol, Bristol BS1 3NY, United Kingdom; School of Physiology and Pharmacology (J.F.R.P.), University of Bristol, Bristol BS8 1TD, United Kingdom; and Department of Physiology (D.M.), University of Malaya, Kuala Lumpur, Malaysia 50603
| | - David Murphy
- School of Clinical Sciences (M.P.G., M.G., D.M.), University of Bristol, Bristol BS1 3NY, United Kingdom; School of Physiology and Pharmacology (J.F.R.P.), University of Bristol, Bristol BS8 1TD, United Kingdom; and Department of Physiology (D.M.), University of Malaya, Kuala Lumpur, Malaysia 50603
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A RNA-Seq Analysis of the Rat Supraoptic Nucleus Transcriptome: Effects of Salt Loading on Gene Expression. PLoS One 2015; 10:e0124523. [PMID: 25897513 PMCID: PMC4405539 DOI: 10.1371/journal.pone.0124523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/16/2015] [Indexed: 11/19/2022] Open
Abstract
Magnocellular neurons (MCNs) in the hypothalamo-neurohypophysial system (HNS) are highly specialized to release large amounts of arginine vasopressin (Avp) or oxytocin (Oxt) into the blood stream and play critical roles in the regulation of body fluid homeostasis. The MCNs are osmosensory neurons and are excited by exposure to hypertonic solutions and inhibited by hypotonic solutions. The MCNs respond to systemic hypertonic and hypotonic stimulation with large changes in the expression of their Avp and Oxt genes, and microarray studies have shown that these osmotic perturbations also cause large changes in global gene expression in the HNS. In this paper, we examine gene expression in the rat supraoptic nucleus (SON) under normosmotic and chronic salt-loading SL) conditions by the first time using "new-generation", RNA sequencing (RNA-Seq) methods. We reliably detect 9,709 genes as present in the SON by RNA-Seq, and 552 of these genes were changed in expression as a result of chronic SL. These genes reflect diverse functions, and 42 of these are involved in either transcriptional or translational processes. In addition, we compare the SON transcriptomes resolved by RNA-Seq methods with the SON transcriptomes determined by Affymetrix microarray methods in rats under the same osmotic conditions, and find that there are 6,466 genes present in the SON that are represented in both data sets, although 1,040 of the expressed genes were found only in the microarray data, and 2,762 of the expressed genes are selectively found in the RNA-Seq data and not the microarray data. These data provide the research community a comprehensive view of the transcriptome in the SON under normosmotic conditions and the changes in specific gene expression evoked by salt loading.
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Greenwood MP, Mecawi AS, Hoe SZ, Mustafa MR, Johnson KR, Al-Mahmoud GA, Elias LLK, Paton JFR, Antunes-Rodrigues J, Gainer H, Murphy D, Hindmarch CCT. A comparison of physiological and transcriptome responses to water deprivation and salt loading in the rat supraoptic nucleus. Am J Physiol Regul Integr Comp Physiol 2015; 308:R559-68. [PMID: 25632023 DOI: 10.1152/ajpregu.00444.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/21/2015] [Indexed: 01/16/2023]
Abstract
Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, arginine vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. On osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function-related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared with euhydrated (EU) controls in terms of drinking and eating behavior, body weight, and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL and remined data from the SON that describes the transcriptome response to WD. From a list of 2,783 commonly regulated transcripts, we selected 20 genes for validation by qPCR. All of the 9 genes that have already been described as expressed or regulated in the SON by osmotic stimuli were confirmed in our models. Of the 11 novel genes, 5 were successfully validated while 6 were false discoveries.
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Affiliation(s)
| | - Andre S Mecawi
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil
| | - See Ziau Hoe
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kory R Johnson
- Clinical Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Ghada A Al-Mahmoud
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Al Tarfa, Doha, Qatar
| | - Lucila L K Elias
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian F R Paton
- School of Physiology and Pharmacology, University Walk, Bristol, United Kingdom; and
| | - Jose Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Harold Gainer
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - David Murphy
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Charles C T Hindmarch
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia;
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Abstract
Arginine vasopressin (AVP) is a neurohypophysial hormone regulating hydromineral homeostasis. Here we show that the mRNA encoding cAMP responsive element-binding protein-3 like-1 (CREB3L1), a transcription factor of the CREB/activating transcription factor (ATF) family, increases in expression in parallel with AVP expression in supraoptic nuclei (SONs) and paraventicular nuclei (PVNs) of dehydrated (DH) and salt-loaded (SL) rats, compared with euhydrated (EH) controls. In EH animals, CREB3L1 protein is expressed in glial cells, but only at a low level in SON and PVN neurons, whereas robust upregulation in AVP neurons accompanied DH and SL rats. Concomitantly, CREB3L1 is activated by cleavage, with the N-terminal domain translocating from the Golgi, via the cytosol, to the nucleus. We also show that CREB3L1 mRNA levels correlate with AVP transcription level in SONs and PVNs following sodium depletion, and as a consequence of diurnal rhythm in the suprachiasmatic nucleus. We tested the hypothesis that CREB3L1 activates AVP gene transcription. Both full-length and constitutively active forms of CREB3L1 (CREB3L1CA) induce the expression of rat AVP promoter-luciferase reporter constructs, whereas a dominant-negative mutant reduces expression. Rat AVP promoter deletion constructs revealed that CRE-like and G-box sequences in the region between -170 and -120 bp are important for CREB3L1 actions. Direct binding of CREB3L1 to the AVP promoter was shown by chromatin immunoprecipitation both in vitro and in the SON itself. Injection of a lentiviral vector expressing CREB3L1CA into rat SONs and PVNs resulted in increased AVP biosynthesis. We thus identify CREB3L1 as a regulator of AVP transcription in the rat hypothalamus.
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Hindmarch CCT, Franses P, Goodwin B, Murphy D. Whole transcriptome organisation in the dehydrated supraoptic nucleus. Braz J Med Biol Res 2013; 46:1000-1006. [PMID: 24345907 PMCID: PMC3935270 DOI: 10.1590/1414-431x20133328] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/11/2013] [Indexed: 01/20/2023] Open
Abstract
The supraoptic nucleus (SON) is part of the central osmotic circuitry that synthesises the hormone vasopressin (Avp) and transports it to terminals in the posterior lobe of the pituitary. Following osmotic stress such as dehydration, this tissue undergoes morphological, electrical and transcriptional changes to facilitate the appropriate regulation and release of Avp into the circulation where it conserves water at the level of the kidney. Here, the organisation of the whole transcriptome following dehydration is modelled to fit Zipf's law, a natural power law that holds true for all natural languages, that states if the frequency of word usage is plotted against its rank, then the log linear regression of this is -1. We have applied this model to our previously published euhydrated and dehydrated SON data to observe this trend and how it changes following dehydration. In accordance with other studies, our whole transcriptome data fit well with this model in the euhydrated SON microarrays, but interestingly, fit better in the dehydrated arrays. This trend was observed in a subset of differentially regulated genes and also following network reconstruction using a third-party database that mines public data. We make use of language as a metaphor that helps us philosophise about the role of the whole transcriptome in providing a suitable environment for the delivery of Avp following a survival threat like dehydration.
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Affiliation(s)
- C C T Hindmarch
- University of Bristol, The Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Bristol, UK
| | | | | | - D Murphy
- University of Bristol, The Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Bristol, UK
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Hazell GG, Hindmarch CC, Pope GR, Roper JA, Lightman SL, Murphy D, O’Carroll AM, Lolait SJ. G protein-coupled receptors in the hypothalamic paraventricular and supraoptic nuclei--serpentine gateways to neuroendocrine homeostasis. Front Neuroendocrinol 2012; 33:45-66. [PMID: 21802439 PMCID: PMC3336209 DOI: 10.1016/j.yfrne.2011.07.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 06/24/2011] [Accepted: 07/06/2011] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors in the mammalian genome. They are activated by a multitude of different ligands that elicit rapid intracellular responses to regulate cell function. Unsurprisingly, a large proportion of therapeutic agents target these receptors. The paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus are important mediators in homeostatic control. Many modulators of PVN/SON activity, including neurotransmitters and hormones act via GPCRs--in fact over 100 non-chemosensory GPCRs have been detected in either the PVN or SON. This review provides a comprehensive summary of the expression of GPCRs within the PVN/SON, including data from recent transcriptomic studies that potentially expand the repertoire of GPCRs that may have functional roles in these hypothalamic nuclei. We also present some aspects of the regulation and known roles of GPCRs in PVN/SON, which are likely complemented by the activity of 'orphan' GPCRs.
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Affiliation(s)
| | | | | | | | | | | | | | - Stephen J. Lolait
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, School of Clinical Sciences, University of Bristol, Whitson Street, Bristol BS1 3NY, UK
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Qiu J, Hindmarch CCT, Yao ST, Tasker JG, Murphy D. Transcriptomic analysis of the osmotic and reproductive remodeling of the female rat supraoptic nucleus. Endocrinology 2011; 152:3483-91. [PMID: 21791562 PMCID: PMC3159778 DOI: 10.1210/en.2011-1044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The supraoptic nucleus (SON) of the hypothalamus is an important integrative brain structure that coordinates responses to perturbations in water balance and regulates maternal physiology through the release of the neuropeptide hormones vasopressin and oxytocin into the circulation. Both dehydration and lactation evoke a dramatic morphological remodeling of the SON, a process known as function-related plasticity. We hypothesize that some of the changes seen in SON remodeling are mediated by differential gene expression, and have thus used microarrays to document global changes in transcript abundance that accompany chronic dehydration in female rats, and in lactation. In situ hybridization analysis has confirmed the differential expression of three of these genes, namely TNF-induced protein 6, gonadotropin-inducible transcription factor 1, and ornithine decarboxylase antizyme inhibitor 1. Comparison of differential gene expression patterns in male and female rats subjected to dehydration and in lactating rats has enabled the identification of common elements that are significantly enriched in gene classes with particular functions. Two of these are related to the requirement for increased protein synthesis and hormone delivery in the physiologically stimulated SON (translation initiation factor activity and endoplasmic reticulum-Golgi intermediate compartment, respectively), whereas others are consistent with the concept of SON morphological plasticity (collagen fibril organization, extracellular matrix organization and biogenesis, extracellular structure organization and biogenesis, and homophilic cell adhesion). We suggest that the genes coordinately regulated in the SON as a consequence of dehydration and lactation form a network that mediates the plastic processes operational in the physiologically activated SON.
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Affiliation(s)
- Jing Qiu
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Whitson Street, Bristol BS1 3NY, United Kingdom
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