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Winter J, Meyer M, Berger I, Royer M, Bianchi M, Kuffner K, Peters S, Stang S, Langgartner D, Hartmann F, Schmidtner AK, Reber SO, Bosch OJ, Bludau A, Slattery DA, van den Burg EH, Jurek B, Neumann ID. Chronic oxytocin-driven alternative splicing of Crfr2α induces anxiety. Mol Psychiatry 2023; 28:4742-4755. [PMID: 34035479 PMCID: PMC10914602 DOI: 10.1038/s41380-021-01141-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 03/25/2021] [Accepted: 04/20/2021] [Indexed: 12/26/2022]
Abstract
The neuropeptide oxytocin (OXT) has generated considerable interest as potential treatment for psychiatric disorders, including anxiety and autism spectrum disorders. However, the behavioral and molecular consequences associated with chronic OXT treatment and chronic receptor (OXTR) activation have scarcely been studied, despite the potential therapeutic long-term use of intranasal OXT. Here, we reveal that chronic OXT treatment over two weeks increased anxiety-like behavior in rats, with higher sensitivity in females, contrasting the well-known anxiolytic effect of acute OXT. The increase in anxiety was transient and waned 5 days after the infusion has ended. The behavioral effects of chronic OXT were paralleled by activation of an intracellular signaling pathway, which ultimately led to alternative splicing of hypothalamic corticotropin-releasing factor receptor 2α (Crfr2α), an important modulator of anxiety. In detail, chronic OXT shifted the splicing ratio from the anxiolytic membrane-bound (mCRFR2α) form of CRFR2α towards the soluble CRFR2α (sCRFR2α) form. Experimental induction of alternative splicing mimicked the anxiogenic effects of chronic OXT, while sCRFR2α-knock down reduced anxiety-related behavior of male rats. Furthermore, chronic OXT treatment triggered the release of sCRFR2α into the cerebrospinal fluid with sCRFR2α levels positively correlating with anxiety-like behavior. In summary, we revealed that the shifted splicing ratio towards expression of the anxiogenic sCRFR2α underlies the adverse effects of chronic OXT treatment on anxiety.
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Affiliation(s)
- Julia Winter
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Magdalena Meyer
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Ilona Berger
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Melanie Royer
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Marta Bianchi
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Kerstin Kuffner
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Sebastian Peters
- Department of Neurology, University Hospital Regensburg, Regensburg, Germany
| | - Simone Stang
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Dominik Langgartner
- Laboratory for Molecular Psychosomatics, Department of Psychosomatic Medicine and Psychotherapy, University of Ulm, Ulm, Germany
| | - Finn Hartmann
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Anna K Schmidtner
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Stefan O Reber
- Laboratory for Molecular Psychosomatics, Department of Psychosomatic Medicine and Psychotherapy, University of Ulm, Ulm, Germany
| | - Oliver J Bosch
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Anna Bludau
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - David A Slattery
- Laboratory of Translational Psychiatry, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University of Frankfurt, Frankfurt am Main, Germany
| | - Erwin H van den Burg
- Center for Psychiatric Neurosciences, University Hospital Lausanne, Lausanne, Switzerland
| | - Benjamin Jurek
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany
| | - Inga D Neumann
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany.
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Squillacioti C, Pelagalli A, Liguori G, Mirabella N. Urocortins in the mammalian endocrine system. Acta Vet Scand 2019; 61:46. [PMID: 31585551 PMCID: PMC6778379 DOI: 10.1186/s13028-019-0480-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 09/21/2019] [Indexed: 12/13/2022] Open
Abstract
Urocortins (Ucns), peptides belonging to the corticotropin-releasing hormone (CRH) family, are classified into Ucn1, Ucn2, and Ucn3. They are involved in regulating several body functions by binding to two G protein-coupled receptors: receptor type 1 (CRHR1) and type 2 (CRHR2). In this review, we provide a historical overview of research on Ucns and their receptors in the mammalian endocrine system. Although the literature on the topic is limited, we focused our attention particularly on the main role of Ucns and their receptors in regulating the hypothalamic–pituitary–adrenal and thyroid axes, reproductive organs, pancreas, gastrointestinal tract, and other tissues characterized by “diffuse” endocrine cells in mammals. The prominent function of these peptides in health conditions led us to also hypothesize an action of Ucn agonists/antagonists in stress and in various diseases with its critical consequences on behavior and physiology. The potential role of the urocortinergic system is an intriguing topic that deserves further in-depth investigations to develop novel strategies for preventing stress-related conditions and treating endocrine diseases.
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Dedic N, Chen A, Deussing JM. The CRF Family of Neuropeptides and their Receptors - Mediators of the Central Stress Response. Curr Mol Pharmacol 2018; 11:4-31. [PMID: 28260504 PMCID: PMC5930453 DOI: 10.2174/1874467210666170302104053] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 11/26/2015] [Accepted: 08/03/2016] [Indexed: 12/12/2022]
Abstract
Background: Dysregulated stress neurocircuits, caused by genetic and/or environmental changes, underlie the development of many neuropsychiatric disorders. Corticotropin-releasing factor (CRF) is the major physiological activator of the hypothalamic-pituitary-adrenal (HPA) axis and conse-quently a primary regulator of the mammalian stress response. Together with its three family members, urocortins (UCNs) 1, 2, and 3, CRF integrates the neuroendocrine, autonomic, metabolic and behavioral responses to stress by activating its cognate receptors CRFR1 and CRFR2. Objective: Here we review the past and current state of the CRF/CRFR field, ranging from pharmacologi-cal studies to genetic mouse models and virus-mediated manipulations. Results: Although it is well established that CRF/CRFR1 signaling mediates aversive responses, includ-ing anxiety and depression-like behaviors, a number of recent studies have challenged this viewpoint by revealing anxiolytic and appetitive properties of specific CRF/CRFR1 circuits. In contrast, the UCN/CRFR2 system is less well understood and may possibly also exert divergent functions on physiol-ogy and behavior depending on the brain region, underlying circuit, and/or experienced stress conditions. Conclusion: A plethora of available genetic tools, including conventional and conditional mouse mutants targeting CRF system components, has greatly advanced our understanding about the endogenous mecha-nisms underlying HPA system regulation and CRF/UCN-related neuronal circuits involved in stress-related behaviors. Yet, the detailed pathways and molecular mechanisms by which the CRF/UCN-system translates negative or positive stimuli into the final, integrated biological response are not completely un-derstood. The utilization of future complementary methodologies, such as cell-type specific Cre-driver lines, viral and optogenetic tools will help to further dissect the function of genetically defined CRF/UCN neurocircuits in the context of adaptive and maladaptive stress responses.
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Affiliation(s)
- Nina Dedic
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr, 2-10, 80804 Munich. Germany
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr, 2-10, 80804 Munich. Germany
| | - Jan M Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr, 2-10, 80804 Munich. Germany
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Deussing JM, Chen A. The Corticotropin-Releasing Factor Family: Physiology of the Stress Response. Physiol Rev 2018; 98:2225-2286. [DOI: 10.1152/physrev.00042.2017] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The physiological stress response is responsible for the maintenance of homeostasis in the presence of real or perceived challenges. In this function, the brain activates adaptive responses that involve numerous neural circuits and effector molecules to adapt to the current and future demands. A maladaptive stress response has been linked to the etiology of a variety of disorders, such as anxiety and mood disorders, eating disorders, and the metabolic syndrome. The neuropeptide corticotropin-releasing factor (CRF) and its relatives, the urocortins 1–3, in concert with their receptors (CRFR1, CRFR2), have emerged as central components of the physiological stress response. This central peptidergic system impinges on a broad spectrum of physiological processes that are the basis for successful adaptation and concomitantly integrate autonomic, neuroendocrine, and behavioral stress responses. This review focuses on the physiology of CRF-related peptides and their cognate receptors with the aim of providing a comprehensive up-to-date overview of the field. We describe the major molecular features covering aspects of gene expression and regulation, structural properties, and molecular interactions, as well as mechanisms of signal transduction and their surveillance. In addition, we discuss the large body of published experimental studies focusing on state-of-the-art genetic approaches with high temporal and spatial precision, which collectively aimed to dissect the contribution of CRF-related ligands and receptors to different levels of the stress response. We discuss the controversies in the field and unravel knowledge gaps that might pave the way for future research directions and open up novel opportunities for therapeutic intervention.
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Affiliation(s)
- Jan M. Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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Winter J, Jurek B. The interplay between oxytocin and the CRF system: regulation of the stress response. Cell Tissue Res 2018; 375:85-91. [PMID: 29911261 DOI: 10.1007/s00441-018-2866-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/31/2018] [Indexed: 01/28/2023]
Abstract
Oxytocin (OT) has drawn the attention of researchers since 1930. Since then, many aspects of oxytocin have been uncovered, such as reproductive functions, dampening anxiety, enhancing socioemotional behavior, or regulating genomic effects on a cellular level. Here, we want to focus on the interaction between the OT system and the stress/corticotropin-releasing factor (CRF)-system of the brain. Depending on the nature of the stressor, OT is released simultaneously or directly after the stress from the neurohypophysis into the periphery and/or via somato-dendritic release in stress-sensitive brain areas. This stress-induced OT release might serve to modulate or dampen the stress response; however, the functional relevance is not yet fully understood. In this review, we will describe the effects of OT and discuss the interplay between OT and CRF on a cellular, physiological, and behavioral level.
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Affiliation(s)
- Julia Winter
- Department of Behavioral and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany.
| | - Ben Jurek
- Department of Behavioral and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany
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Abstract
Corticotrophin-releasing hormone (CRH) is the pivotal neuroendocrine peptide hormone associated with the regulation of the stress response in vertebrates. However, CRH-like peptides are also found in a number of invertebrate species. The origin of this peptide can be traced to a common ancestor of lineages leading to chordates and to arthropods, postulated to occur some 500 million years ago. Evidence indicates the presence of a single CRH-like receptor and a soluble binding protein system that acted to transduce and regulate the actions of the early CRH peptide. In vertebrates, genome duplications led to the divergence of CRH receptors into CRH1 and CRH2 forms in tandem with the development of four paralogous ligand lineages that included CRH; urotensin I/urocortin (Ucn), Ucn2 and Ucn3. In addition, taxon-specific genome duplications led to further local divergences in CRH ligands and receptors. Functionally, the CRH ligand-receptor system evolved initially as a molecular system to integrate early diuresis and nutrient acquisition. As multicellular organisms evolved into more complex forms, this ligand-receptor system became integrated with the organismal stress response to coordinate homoeostatic challenges with internal energy usage. In vertebrates, CRH and the CRH1 receptor became associated with the hypothalamo-pituitary-adrenal/interrenal axis and the initial stress response, whereas the CRH2 receptor was selected to play a greater role in diuresis, nutrient acquisition and the latter aspects of the stress response.
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Affiliation(s)
- David A Lovejoy
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Belinda S W Chang
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, CanadaDepartment of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Nathan R Lovejoy
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Jon del Castillo
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
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Wood SK, Zhang XY, Reyes BA, Lee CS, Van Bockstaele EJ, Valentino RJ. Cellular adaptations of dorsal raphe serotonin neurons associated with the development of active coping in response to social stress. Biol Psychiatry 2013; 73:1087-94. [PMID: 23452664 PMCID: PMC3648616 DOI: 10.1016/j.biopsych.2013.01.026] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Social stress is a risk factor for affective disorders for certain vulnerable individuals. Stress and depression are linked in part through regulation of the dorsal raphe (DR)-serotonin (5-HT) system by the stress-related neuropeptide, corticotropin-releasing factor (CRF). We used a rat social stress model that shows individual differences in coping strategies to determine whether differences in CRF-5-HT interactions underlie individual differences in the vulnerability to social stress. METHODS Rats were exposed to the resident-intruder model of social stress for 5 days. In vivo single-unit recordings assessed DR-5-HT neuronal responses to CRF and immunoelectron microscopy assessed CRF1 and CRF2 cellular localization 24 hours after the last stress. RESULTS Rats responded to social stress passively, assuming defeat with short latencies (48%), or actively, with proactive behaviors and longer defeat latencies (LL, 52%). Whereas CRF (30 ng, intra-DR) inhibited 5-HT neuronal activity of control and SL rats, it activated 5-HT neurons of LL rats, an effect that was CRF2-mediated. Consistent with this, social stress promoted CRF1 internalization together with CRF2 recruitment to the plasma membrane of DR neurons selectively in LL rats. CONCLUSIONS These data suggest that a proactive coping strategy toward social stress is associated with a redistribution of CRF1 and CRF2 in DR-5-HT neurons that primes the system to be activated by subsequent stress. The lack of this adaptation in passive coping rats may contribute to their depressive-like phenotype. These studies provide a cellular mechanism for individual differences in stress responses and consequences.
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Affiliation(s)
- Susan K. Wood
- Department of Anesthesia and Critical Care Medicine, Division of Stress Neurobiology, The Children’s Hospital of Philadelphia, Civic Center Blvd., Philadelphia, PA 19104
| | - Xiao-Yan Zhang
- Department of Anesthesia and Critical Care Medicine, Division of Stress Neurobiology, The Children’s Hospital of Philadelphia, Civic Center Blvd., Philadelphia, PA 19104
| | - Beverly A.S. Reyes
- Department of Neuroscience, Thomas Jefferson University, Farber Institute for Neurosciences, Philadelphia, PA 19107
| | - Catherine S. Lee
- Department of Anesthesia and Critical Care Medicine, Division of Stress Neurobiology, The Children’s Hospital of Philadelphia, Civic Center Blvd., Philadelphia, PA 19104
| | - Elisabeth J. Van Bockstaele
- Department of Neuroscience, Thomas Jefferson University, Farber Institute for Neurosciences, Philadelphia, PA 19107
| | - Rita J. Valentino
- Department of Anesthesia and Critical Care Medicine, Division of Stress Neurobiology, The Children’s Hospital of Philadelphia, Civic Center Blvd., Philadelphia, PA 19104
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Kelemen O, Convertini P, Zhang Z, Wen Y, Shen M, Falaleeva M, Stamm S. Function of alternative splicing. Gene 2013; 514:1-30. [PMID: 22909801 PMCID: PMC5632952 DOI: 10.1016/j.gene.2012.07.083] [Citation(s) in RCA: 504] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/21/2012] [Accepted: 07/30/2012] [Indexed: 12/15/2022]
Abstract
Almost all polymerase II transcripts undergo alternative pre-mRNA splicing. Here, we review the functions of alternative splicing events that have been experimentally determined. The overall function of alternative splicing is to increase the diversity of mRNAs expressed from the genome. Alternative splicing changes proteins encoded by mRNAs, which has profound functional effects. Experimental analysis of these protein isoforms showed that alternative splicing regulates binding between proteins, between proteins and nucleic acids as well as between proteins and membranes. Alternative splicing regulates the localization of proteins, their enzymatic properties and their interaction with ligands. In most cases, changes caused by individual splicing isoforms are small. However, cells typically coordinate numerous changes in 'splicing programs', which can have strong effects on cell proliferation, cell survival and properties of the nervous system. Due to its widespread usage and molecular versatility, alternative splicing emerges as a central element in gene regulation that interferes with almost every biological function analyzed.
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Affiliation(s)
- Olga Kelemen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Paolo Convertini
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhaiyi Zhang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Yuan Wen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Marina Falaleeva
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
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Furness SGB, Wootten D, Christopoulos A, Sexton PM. Consequences of splice variation on Secretin family G protein-coupled receptor function. Br J Pharmacol 2012; 166:98-109. [PMID: 21718310 DOI: 10.1111/j.1476-5381.2011.01571.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The Secretin family of GPCRs are endocrine peptide hormone receptors that share a common genomic organization and are the subject of a wide variety of alternative splicing. All GPCRs contain a central seven transmembrane domain responsible for transducing signals from the outside of the cell as well as extracellular amino and intracellular carboxyl termini. Members of the Secretin receptor family have a relatively large N-terminus and a variety of lines of evidence support a common mode of ligand binding and a common ligand binding fold. These receptors are best characterized as coupling to intracellular signalling pathways via G(αs) and G(αq) but are also reported to couple to a multitude of other signalling pathways. The intracellular loops are implicated in regulating the interaction between the receptor and heterotrimeric G protein complexes. Alternative splicing of exons encoding both the extracellular N-terminal domain as well as the extracellular loops of some family members has been reported and as expected these splice variants display altered ligand affinity as well as differential activation by endogenous ligands. Various forms of alternative splicing have also been reported to alter intracellular loops 1 and 3 as well as the C-terminus and as one might expect these display differences in signalling bias towards downstream effectors. These diverse pharmacologies require that the physiological role of these splice variants be addressed but should provide unique opportunities for drug design and development.
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Teichmann A, Rutz C, Kreuchwig A, Krause G, Wiesner B, Schülein R. The Pseudo signal peptide of the corticotropin-releasing factor receptor type 2A prevents receptor oligomerization. J Biol Chem 2012; 287:27265-74. [PMID: 22689579 DOI: 10.1074/jbc.m112.360594] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-terminal signal peptides mediate the interaction of native proteins with the translocon complex of the endoplasmic reticulum membrane and are cleaved off during early protein biogenesis. The corticotropin-releasing factor receptor type 2a (CRF(2(a))R) possesses an N-terminal pseudo signal peptide, which represents a so far unique domain within the large protein family of G protein-coupled receptors (GPCRs). In contrast to a conventional signal peptide, the pseudo signal peptide remains uncleaved and consequently forms a hydrophobic extension at the N terminus of the receptor. The functional consequence of the presence of the pseudo signal peptide is not understood. Here, we have analyzed the significance of this domain for receptor dimerization/oligomerization in detail. To this end, we took the CRF(2(a))R and the homologous corticotropin-releasing factor receptor type 1 (CRF(1)R) possessing a conventional cleaved signal peptide and conducted signal peptide exchange experiments. Using single cell and single molecule imaging methods (fluorescence resonance energy transfer and fluorescence cross-correlation spectroscopy, respectively) as well as biochemical experiments, we obtained two novel findings; we could show that (i) the CRF(2(a))R is expressed exclusively as a monomer, and (ii) the presence of the pseudo signal peptide prevents its oligomerization. Thus, we have identified a novel functional domain within the GPCR protein family, which plays a role in receptor oligomerization and which may be useful to study the functional significance of this process in general.
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Affiliation(s)
- Anke Teichmann
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
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Lukkes JL, Staub DR, Dietrich A, Truitt W, Neufeld-Cohen A, Chen A, Johnson PL, Shekhar A, Lowry CA. Topographical distribution of corticotropin-releasing factor type 2 receptor-like immunoreactivity in the rat dorsal raphe nucleus: co-localization with tryptophan hydroxylase. Neuroscience 2011; 183:47-63. [PMID: 21453754 DOI: 10.1016/j.neuroscience.2011.03.047] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 03/04/2011] [Accepted: 03/22/2011] [Indexed: 01/07/2023]
Abstract
Corticotropin-releasing factor (CRF) and CRF-related neuropeptides are involved in the regulation of stress-related physiology and behavior. Members of the CRF family of neuropeptides bind to two known receptors, the CRF type 1 (CRF₁) receptor, and the CRF type 2 (CRF₂) receptor. Although the distribution of CRF₂ receptor mRNA expression has been extensively studied, the distribution of CRF₂ receptor protein has not been characterized. An area of the brain known to contain high levels of CRF₂ receptor mRNA expression and CRF₂ receptor binding is the dorsal raphe nucleus (DR). In the present study we investigated in detail the distribution of CRF₂ receptor immunoreactivity throughout the rostrocaudal extent of the DR. CRF₂ receptor-immunoreactive perikarya were observed throughout the DR, with the highest number and density in the mid-rostrocaudal DR. Dual immunofluorescence revealed that CRF₂ receptor immunoreactivity was frequently co-localized with tryptophan hydroxylase, a marker of serotonergic neurons. This study provides evidence that CRF₂ receptor protein is expressed in the DR, and that CRF₂ receptors are expressed in topographically organized subpopulations of cells in the DR, including serotonergic neurons. Furthermore, these data are consistent with the hypothesis that CRF₂ receptors play an important role in the regulation of stress-related physiology and behavior through actions on serotonergic and non-serotonergic neurons within the DR.
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Affiliation(s)
- J L Lukkes
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA.
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Abstract
The complex mechanisms controlling human parturition involves mother, fetus, and placenta, and stress is a key element activating a series of physiological adaptive responses. Preterm birth is a clinical syndrome that shares several characteristics with term birth. A major role for the neuroendocrine mechanisms has been proposed, and placenta/membranes are sources for neurohormones and peptides. Oxytocin (OT) is the neurohormone whose major target is uterine contractility and placenta represents a novel source that contributes to the mechanisms of parturition. The CRH/urocortin (Ucn) family is another important neuroendocrine pathway involved in term and preterm birth. The CRH/Ucn family consists of four ligands: CRH, Ucn, Ucn2, and Ucn3. These peptides have a pleyotropic function and are expressed by human placenta and fetal membranes. Uterine contractility, blood vessel tone, and immune function are influenced by CRH/Ucns during pregnancy and undergo major changes at parturition. Among the others, neurohormones, relaxin, parathyroid hormone-related protein, opioids, neurosteroids, and monoamines are expressed and secreted from placental tissues at parturition. Preterm birth is the consequence of a premature and sustained activation of endocrine and immune responses. A preterm birth evidence for a premature activation of OT secretion as well as increased maternal plasma CRH levels suggests a pathogenic role of these neurohormones. A decrease of maternal serum CRH-binding protein is a concurrent event. At midgestation, placental hypersecretion of CRH or Ucn has been proposed as a predictive marker of subsequent preterm delivery. While placenta represents the major source for CRH, fetus abundantly secretes Ucn and adrenal dehydroepiandrosterone in women with preterm birth. The relevant role of neuroendocrine mechanisms in preterm birth is sustained by basic and clinic implications.
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Affiliation(s)
- Felice Petraglia
- University of Siena, Policlinico, Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics, and Reproductive Medicine, Viale Bracci, 53100 Siena, Italy.
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Stengel A, Taché Y. Corticotropin-releasing factor signaling and visceral response to stress. Exp Biol Med (Maywood) 2010; 235:1168-78. [PMID: 20881321 PMCID: PMC3169435 DOI: 10.1258/ebm.2010.009347] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Stress may cause behavioral and/or psychiatric manifestations such as anxiety and depression and also impact on the function of different visceral organs, namely the gastrointestinal and cardiovascular systems. During the past years substantial progress has been made in the understanding of the underlying mechanisms recruited by stressors. Activation of the corticotropin-releasing factor (CRF) signaling system is recognized to be involved in a large number of stress-related behavioral and somatic disorders. This review will outline the present knowledge on the distribution of the CRF system (ligands and receptors) expressed in the brain and peripheral viscera and its relevance in stress-induced alterations of gastrointestinal and cardiovascular functions and the therapeutic potential of CRF(1) receptor antagonists.
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Affiliation(s)
- Andreas Stengel
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Digestive Diseases Division, David Geffen School of Medicine at University of California Los Angeles, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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Larauche M, Kiank C, Tache Y. Corticotropin releasing factor signaling in colon and ileum: regulation by stress and pathophysiological implications. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2009; 60 Suppl 7:33-46. [PMID: 20388944 PMCID: PMC3295842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 12/11/2009] [Indexed: 05/29/2023]
Abstract
It is well established that central corticotropin releasing factor (CRF) signaling mediates the gastrointestinal responses to stress. However, as shown in the brain, both CRF receptors and ligands are also widely expressed in the colon and the ileum of humans and rodents, and stress modulates their expression. Several functional studies documented that peripheral injection of CRF or urocortin stimulates colonic transit, motility, Fos expression in myenteric neurons, and defecation through activation of CRF(1) receptors, whereas it decreases ileal contractility via CRF(2) receptors. Additionally, intraperitoneal administration of CRF induces colonic mast cells degranulation via both CRF(1) and CRF(2) receptors and increases ion secretion and mucosal permeability to macromolecules, which can in turn promote intestinal inflammation and alter visceral sensitivity. Most peripheral CRF-induced alterations of colonic and ileal functions mimic effects which are observed after stress exposure, and CRF receptor antagonists given peripherally prevent stress-induced GI dysfunction. Furthermore, CRF peptides can reproduce secretomotor and mucosal alterations in vitro. Therefore, accumulated clinical and preclinical evidence supports in addition to the brain, a role for peripheral CRF signaling in mediating stress-induced effects on gastrointestinal sensorimotor, mucosal and immune functions, that may be components of underlying mechanisms involved in stress-related impact on inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).
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Affiliation(s)
- M Larauche
- CURE, Digestive Diseases Research Center and Center for Neurobiology of Stress; Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine UCLA and VA Greater Los Angeles Healthcare System, Angeles, California, USA.
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