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Dysfunctional Heteroreceptor Complexes as Novel Targets for the Treatment of Major Depressive and Anxiety Disorders. Cells 2022; 11:cells11111826. [PMID: 35681521 PMCID: PMC9180493 DOI: 10.3390/cells11111826] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/10/2022] [Accepted: 05/20/2022] [Indexed: 02/01/2023] Open
Abstract
Among mental diseases, major depressive disorder (MDD) and anxiety deserve a special place due to their high prevalence and their negative impact both on society and patients suffering from these disorders. Consequently, the development of novel strategies designed to treat them quickly and efficiently, without or at least having limited side effects, is considered a highly important goal. Growing evidence indicates that emerging properties are developed on recognition, trafficking, and signaling of G-protein coupled receptors (GPCRs) upon their heteromerization with other types of GPCRs, receptor tyrosine kinases, and ionotropic receptors such as N-methyl-D-aspartate (NMDA) receptors. Therefore, to develop new treatments for MDD and anxiety, it will be important to identify the most vulnerable heteroreceptor complexes involved in MDD and anxiety. This review focuses on how GPCRs, especially serotonin, dopamine, galanin, and opioid heteroreceptor complexes, modulate synaptic and volume transmission in the limbic networks of the brain. We attempt to provide information showing how these emerging concepts can contribute to finding new ways to treat both MDD and anxiety disorders.
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Kraichely KN, Clinkscales SE, Hendy CM, Mendoza EA, Parnham S, Giuliano MW. Minimal Increments of Hydrophobic Collapse within the N-Terminus of the Neuropeptide Galanin. Biochemistry 2022; 61:1151-1166. [PMID: 35622960 DOI: 10.1021/acs.biochem.2c00141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The neuropeptide galanin has a 35-year history as an intriguing target in drug design owing to its implication as a potential anticonvulsant and neuronal trophic factor among many other therapeutically interesting functions including analgesia and mood alteration. In this study, we report the structural characterization of three synthetic fragments of the galanin N-terminus in buffered aqueous solution: hGal(2-12)KK, hGal(1-12)KK, and hGal(1-17)KK. High-field two-dimensional 1H-1H nuclear magnetic resonance (NMR) data were acquired for these fragments and used to derive distance restraints. We further utilized modified hydrogen bonding and dihedral restraints to reflect chemical shift patterns in the data, which revealed the signature of a weakly folded helix. Together, these sets of restraints were used to generate NMR structures of all three fragments, which depict a core of hydrophobic residues that cluster together regardless of the presence of a helical structure, and correspond to residues in the N-terminus of galanin that have been previously shown to be critical for binding its receptors. The helical structure only appears following the inclusion of Gly(1) in the sequence, and at longer sequence lengths, unlike many other peptides, the helix does not propagate. Rather, a few turns of poorly ordered helix appear to be a secondary consequence of clusters of hydrophobic sidechains that are conserved across all of the peptides in this study; the helices themselves appear ordered as a consequence of this clustering, and these clusters compare directly to those observed recently to make contacts between galanin and two of its receptor subtypes. Collapsed hydrophobic residues therefore organize and compose the functional core of human galanin and raise interesting questions about the nature of the conformational order in ligands that bind cell surface receptors.
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Affiliation(s)
- Katelyn N Kraichely
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424, United States
| | - Sarah E Clinkscales
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424, United States
| | - Cecilia M Hendy
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424, United States
| | - Eric A Mendoza
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424, United States
| | - Stuart Parnham
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Michael W Giuliano
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424, United States
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3
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Exploring the role of neuropeptides in depression and anxiety. Prog Neuropsychopharmacol Biol Psychiatry 2022; 114:110478. [PMID: 34801611 DOI: 10.1016/j.pnpbp.2021.110478] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/13/2021] [Accepted: 11/13/2021] [Indexed: 12/24/2022]
Abstract
Depression is one of the most prevalent forms of mental disorders and is the most common cause of disability in the Western world. Besides, the harmful effects of stress-related mood disorders on the patients themselves, they challenge the health care system with enormous social and economic impacts. Due to the high proportion of patients not responding to existing drugs, finding new treatment strategies has become an important topic in neurobiology, and there is much evidence that neuropeptides are not only involved in the physiology of stress but may also be clinically important. Based on preclinical trial data, new neuropharmaceutical candidates may target neuropeptides and their receptors and are expected to be essential and valuable tools in the treatment of psychiatric disorders. In the current article, we have summarized data obtained from animal models of depressive disorder and transgenic mouse models. We also focus on previously published research data of clinical studies on corticotropin-releasing hormone (CRH), galanin (GAL), neuropeptide Y (NPY), neuropeptide S (NPS), Oxytocin (OXT), vasopressin (VP), cholecystokinin (CCK), and melanin-concentrating hormone (MCH) stress research fields.
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Abebe EC, Mengstie MA, Seid MA, Dejenie TA. Regulatory effects and potential therapeutic implications of alarin in depression, and arguments on its receptor. Front Psychiatry 2022; 13:1051235. [PMID: 36506414 PMCID: PMC9732279 DOI: 10.3389/fpsyt.2022.1051235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022] Open
Abstract
Alarin is a pleiotropic peptide involved in a multitude of putative biological activities, notably, it has a regulatory effect on depression-like behaviors. Although further elucidating research is needed, animal-based cumulative evidence has shown the antidepressant-like effects of alarin. In light of its regulatory role in depression, alarin could be used as a promising antidepressant in future treatment for depression. Nevertheless, the available information is still insufficient and the therapeutic relevance of alarin in depression is still of concern. Moreover, a plethora of studies have reported that the actions of alarin, including antidepressant activities, are mediated by a separate yet unidentified receptor, highlighting the need for more extensive research. This review focuses on the current understanding of the regulatory effects and future therapeutic relevance of alarin on depression, and the arguments on its receptors.
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Affiliation(s)
- Endeshaw Chekol Abebe
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Misganaw Asmamaw Mengstie
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Mohammed Abdu Seid
- Department of Physiology, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Tadesse Asmamaw Dejenie
- Department of Medical Biochemistry, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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5
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Bhave VM, Nectow AR. The dorsal raphe nucleus in the control of energy balance. Trends Neurosci 2021; 44:946-960. [PMID: 34663507 DOI: 10.1016/j.tins.2021.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/04/2021] [Accepted: 09/23/2021] [Indexed: 01/07/2023]
Abstract
Energy balance is orchestrated by an extended network of highly interconnected nuclei across the central nervous system. While much is known about the hypothalamic circuits regulating energy homeostasis, the 'extra-hypothalamic' circuits involved are relatively poorly understood. In this review, we focus on the brainstem's dorsal raphe nucleus (DRN), integrating decades of research linking this structure to the physiologic and behavioral responses that maintain proper energy stores. DRN neurons sense and respond to interoceptive and exteroceptive cues related to energy imbalance and in turn induce appropriate alterations in energy intake and expenditure. The DRN is also molecularly differentiable, with different populations playing distinct and often opposing roles in controlling energy balance. These populations are integrated into the extended circuit known to regulate energy balance. Overall, this review summarizes the key evidence demonstrating an important role for the DRN in regulating energy balance.
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Affiliation(s)
- Varun M Bhave
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Alexander R Nectow
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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Involvement of Neuropeptide Galanin Receptors 2 and 3 in Learning, Memory and Anxiety in Aging Mice. Molecules 2021; 26:molecules26071978. [PMID: 33915732 PMCID: PMC8037218 DOI: 10.3390/molecules26071978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 01/19/2023] Open
Abstract
The neuropeptide galanin (GAL), which is expressed in limbic brain structures, has a strong impact on the regulation of mood and behavior. GAL exerts its effects via three G protein-coupled receptors (GAL1-3-R). Little is known about the effects of aging and loss of GAL-Rs on hippocampal-mediated processes connected to neurogenesis, such as learning, memory recall and anxiety, and cell proliferation and survival in the dorsal dentate gyrus (dDG) in mice. Our results demonstrate that loss of GAL3-R, but not GAL2-R, slowed learning and induced anxiety in older (12-14-month-old) mice. Lack of GAL2-R increased cell survival (BrdU incorporation) in the dDG of young mice. However, normal neurogenesis was observed in vitro using neural stem and precursor cells obtained from GAL2-R and GAL3-R knockouts upon GAL treatment. Interestingly, we found sub-strain differences between C57BL/6J and C57BL/6N mice, the latter showing faster learning, less anxiety and lower cell survival in the dDG. We conclude that GAL-R signaling is involved in cognitive functions and can modulate the survival of cells in the neurogenic niche, which might lead to new therapeutic applications. Furthermore, we observed that the mouse sub-strain had a profound impact on the behavioral parameters analyzed and should therefore be carefully considered in future studies.
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Steinbusch HWM, Dolatkhah MA, Hopkins DA. Anatomical and neurochemical organization of the serotonergic system in the mammalian brain and in particular the involvement of the dorsal raphe nucleus in relation to neurological diseases. PROGRESS IN BRAIN RESEARCH 2021; 261:41-81. [PMID: 33785137 DOI: 10.1016/bs.pbr.2021.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The brainstem is a neglected brain area in neurodegenerative diseases, including Alzheimer's and Parkinson's disease, frontotemporal lobar degeneration and autonomic dysfunction. In Depression, several observations have been made in relation to changes in one particular the Dorsal Raphe Nucleus (DRN) which also points toward as key area in various age-related and neurodevelopmental diseases. The DRN is further thought to be related to stress regulated processes and cognitive events. It is involved in neurodegeneration, e.g., amyloid plaques, neurofibrillary tangles, and impaired synaptic transmission in Alzheimer's disease as shown in our autopsy findings. The DRN is a phylogenetically old brain area, with projections that reach out to a large number of regions and nuclei of the central nervous system, particularly in the forebrain. These ascending projections contain multiple neurotransmitters. One of the main reasons for the past and current interest in the DRN is its involvement in depression, and its main transmitter serotonin. The DRN also points toward the increased importance and focus of the brainstem as key area in various age-related and neurodevelopmental diseases. This review describes the morphology, ascending projections and the complex neurotransmitter nature of the DRN, stressing its role as a key research target into the neural bases of depression.
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Affiliation(s)
- Harry W M Steinbusch
- Department of Cellular Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands; Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology-DGIST, Daegu, South Korea.
| | | | - David A Hopkins
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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Yu M, Fang P, Wang H, Shen G, Zhang Z, Tang Z. Beneficial effects of galanin system on diabetic peripheral neuropathic pain and its complications. Peptides 2020; 134:170404. [PMID: 32898581 DOI: 10.1016/j.peptides.2020.170404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 11/16/2022]
Abstract
Diabetic peripheral neuropathic pain (DPNP) is a distal spontaneous pain, caused by lesion of sensory neurons and accompanied by depression and anxiety frequently, which reduce life quality of patients and increase society expenditure. To date, antidepressants, serotonin-noradrenaline reuptake inhibitors and anticonvulsants are addressed as first-line therapy to DPNP, alone or jointly. It is urgently necessary to develop novel agents to treat DPNP and its complications. Evidences indicate that neuropeptide galanin can regulate multiple physiologic and pathophysiological processes. Pain, depression and anxiety may upregulate galanin expression. In return, galanin can modulate depression, anxiety, pain threshold and pain behaviors. This article provides a new insight into regulative effects of galanin and its subtype receptors on antidepressant, antianxiety and against DPNP. Through activating GALR1, galanin reinforces depression-like and anxiogenic-like behaviors, but exerts antinociceptive roles. While via activating GALR2, galanin is referred to as anti-depressive and anti-anxiotropic compounds, and at low and high concentration facilitates and inhibits nociceptor activity, respectively. The mechanism of the galanin roles is relative to increase in K+ currents and decrease in Ca2+ currents, as well as neurotrophic and neuroprotective roles. These data are helpful to develop novel drugs to treat DPNP and its complications.
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Affiliation(s)
- Mei Yu
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China; Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Penghua Fang
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China
| | - Hua Wang
- Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Guiqin Shen
- Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China.
| | - Zongxiang Tang
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China.
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Demsie DG, Altaye BM, Weldekidan E, Gebremedhin H, Alema NM, Tefera MM, Bantie AT. Galanin Receptors as Drug Target for Novel Antidepressants: Review. Biologics 2020; 14:37-45. [PMID: 32368008 PMCID: PMC7183331 DOI: 10.2147/btt.s240715] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 03/19/2020] [Indexed: 11/23/2022]
Abstract
Galanin (GAL) is a 29-amino-acid neuropeptide that serves multiple physiological functions throughout the central and peripheral nervous system. Its role involves in a range of physiological and pathological functions including control of food intake, neuro-protection, neuronal regeneration, energy expenditure, reproduction, water balance, mood, nociception and various neuroendocrine functions. The use of currently available antidepressant drugs raises concerns regarding efficacy and onset of action; therefore, the need for antidepressants with novel mechanisms is increasing. Presently, various studies revealed the link between GAL and depression. Attenuation of depressive symptoms is achieved through inhibition of GalR1 and GalR3 and activation of GalR2. However, lack of receptor selectivity of ligands has limited the complete elucidation of effects of different receptors in depression-like behavior. Studies have suggested that GAL enhances the action of selective serotonin reuptake inhibitors (SSRIs) and promotes availability of transcription proteins. This review addresses the role of GAL, GAL receptors (GALRs) ligands including selective peptides, and the mechanism of ligand receptor interaction in attenuating depressive symptoms.
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Affiliation(s)
- Desalegn Getnet Demsie
- College of Medicine and Health Sciences, Department of Pharmacy, Adigrat University, Adigrat, Ethiopia
| | | | - Etsay Weldekidan
- College of Medicine and Health Sciences, Department of Pharmacy, Adigrat University, Adigrat, Ethiopia
| | - Hagazi Gebremedhin
- College of Medicine and Health Sciences, Department of Pharmacy, Adigrat University, Adigrat, Ethiopia
| | | | | | - Abere Tilahun Bantie
- College of Medicine and Health Sciences, Department of Anesthesia, Adigrat University, Adigrat, Ethiopia
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10
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Genders SG, Scheller KJ, Djouma E. Neuropeptide modulation of addiction: Focus on galanin. Neurosci Biobehav Rev 2020; 110:133-149. [DOI: 10.1016/j.neubiorev.2018.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
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Tillage RP, Sciolino NR, Plummer NW, Lustberg D, Liles LC, Hsiang M, Powell JM, Smith KG, Jensen P, Weinshenker D. Elimination of galanin synthesis in noradrenergic neurons reduces galanin in select brain areas and promotes active coping behaviors. Brain Struct Funct 2020; 225:785-803. [PMID: 32065256 DOI: 10.1007/s00429-020-02035-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 01/27/2020] [Indexed: 01/08/2023]
Abstract
Accumulating evidence indicates that disruption of galanin signaling is associated with neuropsychiatric disease, but the precise functions of this neuropeptide remain largely unresolved due to lack of tools for experimentally disrupting its transmission in a cell type-specific manner. To examine the function of galanin in the noradrenergic system, we generated and crossed two novel knock-in mouse lines to create animals lacking galanin specifically in noradrenergic neurons (GalcKO-Dbh). We observed reduced levels of galanin peptide in pons, hippocampus, and prefrontal cortex of GalcKO-Dbh mice, indicating that noradrenergic neurons are a significant source of galanin to those brain regions, while midbrain and hypothalamic galanin levels were comparable to littermate controls. In these same brain regions, we observed no change in levels of norepinephrine or its major metabolite at baseline or after an acute stressor, suggesting that loss of galanin does not affect noradrenergic synthesis or turnover. GalcKO-Dbh mice had normal performance in tests of depression, learning, and motor-related behavior, but had an altered response in some anxiety-related tasks. Specifically, GalcKO-Dbh mice showed increased marble and shock probe burying and had a reduced latency to eat in a novel environment, indicative of a more proactive coping strategy. Together, these findings indicate that noradrenergic neurons provide a significant source of galanin to discrete brain areas, and noradrenergic-specific galanin opposes adaptive coping responses.
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Affiliation(s)
- Rachel P Tillage
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA, 30322, USA
| | - Natale R Sciolino
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Nicholas W Plummer
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Daniel Lustberg
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA, 30322, USA
| | - L Cameron Liles
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA, 30322, USA
| | - Madeline Hsiang
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Jeanne M Powell
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Kathleen G Smith
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Patricia Jensen
- Neurobiology Laboratory, Developmental Neurobiology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA, 30322, USA.
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Werner FM, Coveñas R. Therapeutic Effect of Novel Antidepressant Drugs Acting at Specific Receptors of Neurotransmitters and Neuropeptides. Curr Pharm Des 2020; 25:388-395. [PMID: 30969164 DOI: 10.2174/1381612825666190410165243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 03/13/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Major depression is a frequent psychiatric disease. One- third of the depressive patients remain treatment-resistant; thus, it is urgent to find novel antidepressant drugs. OBJECTIVE In major depression, in several brain areas the neural networks involved and the alterations of neurotransmitters and neuropeptides are updated. According to these networks, new pharmacological agents and effective combinations of antidepressant drugs achieving a more efficacious antidepressant treatment are suggested. RESULTS In the neural networks, the prefrontal cortex has been included. In this brain area, glutamatergic neurons, which receive an activating potential from D2 dopaminergic neurons, presynaptically inhibit M1 muscarinic cholinergic neurons via NMDA receptors. Medium spiny GABAergic/somatostatin neurons, which receive projections from M1 muscarinic cholinergic neurons, presynaptically inhibit D2 dopaminergic neurons via GABAA/somatostatin1 receptors. The combination of an NMDA receptor antagonist with an M1 muscarinic cholinergic receptor antagonist can achive a rapid, long-lasting antidepressant effect. CONCLUSION In preclinical studies, the antidepressant effect of orvepitant, an NK1 receptor antagonist, has been demonstrated: this antagonist reaches a complete blockade of NK1 receptors. In clinical studies, the combination of an NMDA receptor antagonist with an M1 muscarinic cholinergic receptor antagonist should be investigated indepth as well as the therapeutic effect of orvepitant. In clinical studies, the antidepressant effect of a triple reuptake inhibitor should be examined and compared to current antidepressant drugs.
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Affiliation(s)
- Felix-Martin Werner
- Höhere Berufsfachschule für Altenpflege und Ergotherapie der Euro Akademie Pößneck, Pößneck, Germany.,Institute of Neurosciences of Castilla y León (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems, University of Salamanca, Salamanca, Spain
| | - Rafael Coveñas
- Institute of Neurosciences of Castilla y León (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems, University of Salamanca, Salamanca, Spain
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Li Y, Gao M, Zeng K, Xing JX, Xu FL, Xuan JF, Xia X, Liu YP, Yao J, Wang BJ. Association Between Polymorphisms in the 5' Region of the GALR1 Gene and Schizophrenia in the Northern Chinese Han Population: A Case-Control Study. Neuropsychiatr Dis Treat 2020; 16:1519-1532. [PMID: 32606704 PMCID: PMC7306470 DOI: 10.2147/ndt.s256644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/22/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Epidemiological studies have shown that genetic factors are among the causes of schizophrenia. Galanin receptor 1 is an inhibitory receptor of galanin that is widely distributed in the central nervous system. This study mainly explored the relationship between polymorphisms of the 5' region of the GALR1 gene and schizophrenia in the northern Chinese Han population. METHODS A 1545 bp fragment of the 5' regulatory region of the GALR1 gene was amplified and sequenced in 289 schizophrenia patients and 347 healthy controls. RESULTS Among the haplotypes composed of the 16 detected SNPs, the haplotype H3 was identified as conferring a risk of schizophrenia (p=0.011, OR=1.430, 95% CI=1.084-1.886). In addition, the haplotypes H4 and H7 were both protective against schizophrenia (p=0.024, OR=0.526, 95% CI=0.298-0.927; p=0.037, OR=0.197, 95% CI=0.044-0.885, respectively). In the subgroup analysis by sex, it was found that seven SNP alleles (rs72978691, rs11662010, rs11151014, rs11151015, rs13306374, rs5373, rs13306375) conferred a risk of schizophrenia in females (p<0.05), while allele G of rs7242919 (p=0.007) was protective against schizophrenia in females. Moreover, the rs72978691 AA+AC genotype (p=0.006, OR=1.874, 95% CI=1.196-2.937, power=0.780), rs7242919 CC+CG genotype (p=0.002, OR=2.027, 95% CI=1.292-3.180, power=0.861), rs11151014 GG+GT genotype (p=0.008, OR=1.834, 95% CI=1.168-2.879, power=0.735), rs11151015 GG+AG genotype (p=0.002, OR=2.013, 95% CI =1.291-3.137, power=0.843), rs13306374 CC+AC genotype (p=0.006, OR=1.881, 95% CI=1.198-2.953, power=0.788), and rs13306375 GG+AG genotype (p=0.006, OR=1.868, 95% CI=1.194-2.921, power=0.770) increased the risk of schizophrenia in females. The haplotype FH2 consisting of rs72978691, rs11662010, rs7242919, rs11151014, rs11151015, rs13306374, rs5373, and rs13306375 may also be associated with the risk of schizophrenia in females (p=0.024). CONCLUSION This study identified an association between polymorphisms in the 5' region of the GALR1 gene and schizophrenia, especially in females.
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Affiliation(s)
- Ya Li
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Meng Gao
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Kuo Zeng
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Jia-Xin Xing
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Feng-Ling Xu
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Jin-Feng Xuan
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Xi Xia
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Yong-Ping Liu
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Jun Yao
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
| | - Bao-Jie Wang
- School of Forensic Medicine, China Medical University, Shenyang 110122, People's Republic of China
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Keszler G, Molnár Z, Rónai Z, Sasvári-Székely M, Székely A, Kótyuk E. Association between anxiety and non-coding genetic variants of the galanin neuropeptide. PLoS One 2019; 14:e0226228. [PMID: 31881033 PMCID: PMC6934320 DOI: 10.1371/journal.pone.0226228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/21/2019] [Indexed: 12/28/2022] Open
Abstract
Background Galanin, an inhibitory neuropeptide and cotransmitter has long been known to co-localize with noradrenaline and serotonin in the central nervous system. Several human studies demonstrated altered galanin expression levels in major depressive disorder and anxiety. Pharmacological modulation of galanin signaling and transgenic strategies provide further proof for the involvement of the galanin system in the pathophysiology of mood disorders. Little is known, however, on the dynamic regulation of galanin expression at the transcriptional level. The aim of the present study was to seek genetic association of non-coding single nucleotide variations in the galanin gene with anxiety and depression. Methods Six single nucleotide polymorphisms (SNP) occurring either in the regulatory 5’ or 3’ flanking regions or within intronic sequences of the galanin gene have been genotyped with a high-throughput TaqMan OpenArray qPCR system in 526 healthy students (40% males). Depression and anxiety scores were obtained by filling in the Hospital Anxiety and Depression Scale (HADS) questionnaire. Data were analyzed by ANCOVA and Bonferroni correction was applied for multiple testing. Linkage disequilibrium (LD) analysis was used to map two haploblocks in the analyzed region. Results and conclusions A single-locus and a haplotype genetic association proved to be statistically significant. In single-marker analysis, the T allele of the rs1042577 SNP within the 3’ untranslated region of the galanin gene associated with greater levels of anxiety (HADS scores were 7.05±4.0 vs 6.15±.15; p = 0.000407). Haplotype analysis revealed an association of the rs948854 C_rs4432027_C allele combination with anxiety [F(1,1046) = 4.140, p = 0.042141, η2 = 0.004, power = 0.529]. Neither of these associations turned out to be gender-specific. These promoter polymorphisms are supposed to participate in epigenetic regulation of galanin expression by creating potentially methylatable CpG dinucleotides. The functional importance of the rs1042577_T allele remains to be elucidated.
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Affiliation(s)
- Gergely Keszler
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Zsuzsanna Molnár
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Zsolt Rónai
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Mária Sasvári-Székely
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Anna Székely
- MTA-ELTE Lendület Adaptation Research Group, Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Eszter Kótyuk
- MTA-ELTE Lendület Adaptation Research Group, Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
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15
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Flores-Burgess A, Millón C, Gago B, García-Durán L, Cantero-García N, Coveñas R, Narváez JA, Fuxe K, Santín L, Díaz-Cabiale Z. Galanin (1–15)-fluoxetine interaction in the novel object recognition test. Involvement of 5-HT1A receptors in the prefrontal cortex of the rats. Neuropharmacology 2019; 155:104-112. [DOI: 10.1016/j.neuropharm.2019.05.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/07/2019] [Accepted: 05/18/2019] [Indexed: 10/26/2022]
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16
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Millón C, Flores-Burgess A, Gago B, Alén F, Orio L, García-Durán L, Narváez JA, Fuxe K, Santín L, Díaz-Cabiale Z. Role of the galanin N-terminal fragment (1-15) in anhedonia: Involvement of the dopaminergic mesolimbic system. J Psychopharmacol 2019; 33:737-747. [PMID: 31081442 DOI: 10.1177/0269881119844188] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Anhedonia is a core feature of depressive disorders. The galanin N-terminal fragment (1-15) plays a role in mood regulation since it induces depression and anxiogenic-like effects in rats. In this study, we analysed galanin N-terminal fragment (1-15) actions in anhedonic-like behaviours in rats using operant and non-operant tests and the areas involved with these effects. METHODS Galanin N-terminal fragment (1-15) effects were analysed in saccharin self-administration, sucrose preference, novelty-suppressed feeding and female urine sniffing tests. The areas involved in galanin N-terminal fragment (1-15)-mediated effects were studied with positron emission tomography for in vivo imaging, and we analysed the ventral tegmental area and nucleus accumbens. Galanin N-terminal fragment (1-15) had effects on the mRNA expression of the dopamine transporters Dat and Vmat2; the C-Fos gene; the dopamine receptors D1, D2, D3, D5; and the galanin receptors 1 and 2. RESULTS Galanin N-terminal fragment (1-15) at a concentration of 3 nmol induced a strong anhedonia-like phenotype in all tests. The involvement of galanin receptor 2 was demonstrated with the galanin receptor 2 antagonist M871 (3 nmol). The 18F-fluorodeoxyglucose positron emission tomography images indicated the action of galanin N-terminal fragment (1-15) over several nuclei of the limbic system. Galanin N-terminal fragment (1-15)-mediated effects also involved changes in the expression of Dat, Vmat2, D3 and galanin receptors in the ventral tegmental area as well as the expression of C-Fos, D1, D2 and D3 and TH immunoreactivity in the nucleus accumbens. CONCLUSIONS Our results indicated that galanin N-terminal fragment (1-15) exerts strong anhedonic-like effects and that this effect was accompanied by changes in the dopaminergic mesolimbic system. These results may provide a basis for the development of novel therapeutic strategies using galanin N-terminal fragment (1-15) analogues for the treatment of depression and reward-related diseases.
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Affiliation(s)
- Carmelo Millón
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain.,2 Departamento de Psicobiología y Metodología en Ciencias del Comportamiento, Facultad de Psicología, Universidad Complutense de Madrid, Madrid, Spain
| | - Antonio Flores-Burgess
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
| | - Belén Gago
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
| | - Francisco Alén
- 2 Departamento de Psicobiología y Metodología en Ciencias del Comportamiento, Facultad de Psicología, Universidad Complutense de Madrid, Madrid, Spain
| | - Laura Orio
- 2 Departamento de Psicobiología y Metodología en Ciencias del Comportamiento, Facultad de Psicología, Universidad Complutense de Madrid, Madrid, Spain
| | - Laura García-Durán
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
| | - José A Narváez
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
| | - Kjell Fuxe
- 3 Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Luis Santín
- 4 Universidad de Málaga, Facultad de Psicología, Instituto de Investigación Biomédica de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
| | - Zaida Díaz-Cabiale
- 1 Universidad de Málaga, Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
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17
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Yun S, Reyes-Alcaraz A, Lee YN, Yong HJ, Choi J, Ham BJ, Sohn JW, Kim DH, Son GH, Kim H, Kwon SG, Kim DS, Kim BC, Hwang JI, Seong JY. Spexin-Based Galanin Receptor Type 2 Agonist for Comorbid Mood Disorders and Abnormal Body Weight. Front Neurosci 2019; 13:391. [PMID: 31057364 PMCID: PMC6482256 DOI: 10.3389/fnins.2019.00391] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/04/2019] [Indexed: 01/18/2023] Open
Abstract
Despite the established comorbidity between mood disorders and abnormal eating behaviors, the underlying molecular mechanism and therapeutics remain to be resolved. Here, we show that a spexin-based galanin receptor type 2 agonist (SG2A) simultaneously normalized mood behaviors and body weight in corticosterone pellet-implanted (CORTI) mice, which are underweight and exhibit signs of anhedonia, increased anxiety, and depression. Administration of SG2A into the lateral ventricle produced antidepressive and anxiolytic effects in CORTI mice. Additionally, SG2A led to a recovery of body weight in CORTI mice while it induced significant weight loss in normal mice. In Pavlovian fear-conditioned mice, SG2A decreased contextual and auditory fear memory consolidation but accelerated the extinction of acquired fear memory without altering innate fear and recognition memory. The main action sites of SG2A in the brain may include serotonergic neurons in the dorsal raphe nucleus for mood control, and proopiomelanocortin/corticotropin-releasing hormone neurons in the hypothalamus for appetite and body weight control. Furthermore, intranasal administration of SG2A exerted the same anxiolytic and antidepressant-like effects and decreased food intake and body weight in a dose-dependent manner. Altogether, these results indicate that SG2A holds promise as a clinical treatment for patients with comorbid mood disorders and abnormal appetite/body weight.
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Affiliation(s)
- Seongsik Yun
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | | | - Yoo-Na Lee
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | - Hyo Jeong Yong
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | - Jeewon Choi
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Byung-Joo Ham
- Department of Psychiatry, College of Medicine, Korea University, Seoul, South Korea
| | - Jong-Woo Sohn
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Dong-Hoon Kim
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | - Gi Hoon Son
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | - Hyun Kim
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | | | | | | | - Jong-Ik Hwang
- Graduate School of Medicine, Korea University, Seoul, South Korea
| | - Jae Young Seong
- Graduate School of Medicine, Korea University, Seoul, South Korea
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18
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Hökfelt T, Barde S, Xu ZQD, Kuteeva E, Rüegg J, Le Maitre E, Risling M, Kehr J, Ihnatko R, Theodorsson E, Palkovits M, Deakin W, Bagdy G, Juhasz G, Prud’homme HJ, Mechawar N, Diaz-Heijtz R, Ögren SO. Neuropeptide and Small Transmitter Coexistence: Fundamental Studies and Relevance to Mental Illness. Front Neural Circuits 2018; 12:106. [PMID: 30627087 PMCID: PMC6309708 DOI: 10.3389/fncir.2018.00106] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/05/2018] [Indexed: 12/31/2022] Open
Abstract
Neuropeptides are auxiliary messenger molecules that always co-exist in nerve cells with one or more small molecule (classic) neurotransmitters. Neuropeptides act both as transmitters and trophic factors, and play a role particularly when the nervous system is challenged, as by injury, pain or stress. Here neuropeptides and coexistence in mammals are reviewed, but with special focus on the 29/30 amino acid galanin and its three receptors GalR1, -R2 and -R3. In particular, galanin's role as a co-transmitter in both rodent and human noradrenergic locus coeruleus (LC) neurons is addressed. Extensive experimental animal data strongly suggest a role for the galanin system in depression-like behavior. The translational potential of these results was tested by studying the galanin system in postmortem human brains, first in normal brains, and then in a comparison of five regions of brains obtained from depressed people who committed suicide, and from matched controls. The distribution of galanin and the four galanin system transcripts in the normal human brain was determined, and selective and parallel changes in levels of transcripts and DNA methylation for galanin and its three receptors were assessed in depressed patients who committed suicide: upregulation of transcripts, e.g., for galanin and GalR3 in LC, paralleled by a decrease in DNA methylation, suggesting involvement of epigenetic mechanisms. It is hypothesized that, when exposed to severe stress, the noradrenergic LC neurons fire in bursts and release galanin from their soma/dendrites. Galanin then acts on somato-dendritic, inhibitory galanin autoreceptors, opening potassium channels and inhibiting firing. The purpose of these autoreceptors is to act as a 'brake' to prevent overexcitation, a brake that is also part of resilience to stress that protects against depression. Depression then arises when the inhibition is too strong and long lasting - a maladaption, allostatic load, leading to depletion of NA levels in the forebrain. It is suggested that disinhibition by a galanin antagonist may have antidepressant activity by restoring forebrain NA levels. A role of galanin in depression is also supported by a recent candidate gene study, showing that variants in genes for galanin and its three receptors confer increased risk of depression and anxiety in people who experienced childhood adversity or recent negative life events. In summary, galanin, a neuropeptide coexisting in LC neurons, may participate in the mechanism underlying resilience against a serious and common disorder, MDD. Existing and further results may lead to an increased understanding of how this illness develops, which in turn could provide a basis for its treatment.
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Affiliation(s)
- Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Zhi-Qing David Xu
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Eugenia Kuteeva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Joelle Rüegg
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- The Center for Molecular Medicine, Stockholm, Sweden
- Swedish Toxicology Sciences Research Center, Swetox, Södertälje, Sweden
| | - Erwan Le Maitre
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mårten Risling
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jan Kehr
- Pronexus Analytical AB, Solna, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Robert Ihnatko
- Department of Clinical Chemistry, Linköping University, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry, Linköping University, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Miklos Palkovits
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - William Deakin
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester, United Kingdom
| | - Gyorgy Bagdy
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
- MTA-SE Neuropsychopharmacology and Neurochemistry Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary
- NAP 2-SE New Antidepressant Target Research Group, Hungarian Brain Research Program, Semmelweis University, Budapest, Hungary
| | - Gabriella Juhasz
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester, United Kingdom
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
- SE-NAP2 Genetic Brain Imaging Migraine Research Group, Hungarian Brain Research Program, Semmelweis University, Budapest, Hungary
| | | | - Naguib Mechawar
- Douglas Hospital Research Centre, Verdun, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | | | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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19
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Podlasz P, Jakimiuk A, Kasica-Jarosz N, Czaja K, Wasowicz K. Neuroanatomical Localization of Galanin in Zebrafish Telencephalon and Anticonvulsant Effect of Galanin Overexpression. ACS Chem Neurosci 2018; 9:3049-3059. [PMID: 30095254 DOI: 10.1021/acschemneuro.8b00239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Galanin is a neuropeptide widely expressed in the nervous system, but it is also present in non-neuronal locations. In the brain, galanin may function as an inhibitory neurotransmitter. Several studies have shown that galanin is involved in seizure regulation and can modulate epileptic activity in the brain. The overall goal of the study was to establish zebrafish as a model to study the antiepileptic effect of galanin. The goal of this study was achieved by (1) determining neuroanatomical localization of galanin in zebrafish lateral pallium, which is considered to be the zebrafish homologue of the mammalian hippocampus, the brain region essential for initiation of seizures, and (2) testing the anticonvulsant effect of galanin overexpression. Whole mount immunofluorescence staining and pentylenotetrazole (PTZ)-seizure model in larval zebrafish using automated analysis of motor function and qPCR were used in the study. Immunohistochemical staining of zebrafish larvae revealed numerous galanin-IR fibers innervating the subpallium, but only scarce fibers reaching the dorsal parts of telencephalon, including lateral pallium. In three-month old zebrafish, galanin-IR innervation of the telencephalon was similar; however, many more galanin-IR fibers reached the dorsal telencephalon, but in the lateral pallium only scarce galanin-IR fibers were visible. qRT-PCR revealed, as expected, a strong increase in the expression of galanin in the Tg(hsp70l:galn) line after heat shock; however, also without heat shock, the galanin expression was several-fold higher than in the control animals. Galanin overexpression resulted in downregulation of c-fos after PTZ treatment. Behavioral analysis showed that galanin overexpression inhibited locomotor activity in PTZ-treated and control larvae. The obtained results show that galanin overexpression reduced the incidence of seizure-like behavior episodes and their intensity but had no significant effect on their duration. The findings indicate that in addition to antiepileptic action, galanin modulates arousal behavior and demonstrates a sedative effect. The current study showed that galanin overexpression correlated with a potent anticonvulsant effect in the zebrafish PTZ-seizure model.
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Affiliation(s)
- Piotr Podlasz
- Department of Pathophysiology, Forensic Veterinary and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Anna Jakimiuk
- Department of Pathophysiology, Forensic Veterinary and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Natalia Kasica-Jarosz
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Krzysztof Czaja
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States
| | - Krzysztof Wasowicz
- Department of Pathophysiology, Forensic Veterinary and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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20
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de Souza MM, Silote GP, Herbst LS, Funck VR, Joca SRL, Beijamini V. The antidepressant-like effect of galanin in the dorsal raphe nucleus of rats involves GAL 2 receptors. Neurosci Lett 2018; 681:26-30. [PMID: 29787787 DOI: 10.1016/j.neulet.2018.05.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/18/2018] [Indexed: 01/27/2023]
Abstract
Galanin is a neuropeptide distributed in human and rat brain regions that are involved with emotional regulation, such as the dorsal raphe nucleus (DRN). Galanin effects in the DRN are mediated by GAL1 and GAL2 receptors. Intracerebral infusion of a GAL2 (AR-M1896) or a GAL1 (M617) agonist induced either antidepressant or depressive-like effect, respectively, in rats exposed to the forced swimming test (FST). However, it is not clear if GAL1 and/or GAL2 receptors present in the DRN would be involved in such effects. Therefore, we investigated the effects induced by intra-DRN infusion of galanin (0.3 nmol), AR-M1896 (1 nmol, GAL2 agonist), or M617 (GAL1 agonist) in rats exposed to the FST. Galanin and AR-M1896 intra-DRN administration induced antidepressant-like effect in the FST. However, M617 did not induce any change in the FST. Neither M617 nor AR-M1896 changed the locomotor activity of rats in the open field test. Intra-DRN pre-treatment with M871 (1 nmol), a selective GAL2 antagonist, counteracted the antidepressant-like effect induced by galanin. These results suggest that galanin signaling through GAL2 receptors in the DRN produces triggers antidepressant-like effect.
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Affiliation(s)
- Mayara Machado de Souza
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Gabriela Pandini Silote
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil; Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Leticia Santos Herbst
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Vinicius Rafael Funck
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Samia Regiane Lourenço Joca
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
| | - Vanessa Beijamini
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil.
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Fang P, Yu M, Wan D, Zhang L, Han L, Shen Z, Shi M, Zhu Y, Zhang Z, Bo P. Regulatory effects of galanin system on development of several age-related chronic diseases. Exp Gerontol 2017; 95:88-97. [DOI: 10.1016/j.exger.2017.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 02/07/2023]
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22
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Millón C, Flores-Burgess A, Narváez M, Borroto-Escuela DO, Gago B, Santín L, Castilla-Ortega E, Narváez JÁ, Fuxe K, Díaz-Cabiale Z. The neuropeptides Galanin and Galanin(1-15) in depression-like behaviours. Neuropeptides 2017; 64:39-45. [PMID: 28196617 DOI: 10.1016/j.npep.2017.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/11/2022]
Abstract
Galanin is a 29 amino acid neuropeptide widely distributed in neurons within the central nervous system. Galanin exerts its biological activities through three different G protein-receptors and participates in a number of functions, including mood regulation. Not only Galanin but also Galanin N-terminal fragments like Galanin(1-15) are active at the central level. In this work, we review the latest findings in studies on Galanin and Galanin(1-15) in depression-related behaviours. Our focus is on animal models for depression, and we pay some attention to research data obtained in human studies. Since Serotonin (5-HT), especially through 5-HT1A, and Galanin receptors interact at both pre-and postsynaptic level, the development of drugs targeting potential GAL1-GAL2-5-HT1A heteroreceptor complexes linked to the raphe-hippocampal 5-HT neurons may represent new treatment strategies in depression.
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Affiliation(s)
- Carmelo Millón
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
| | - Antonio Flores-Burgess
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Manuel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | | | - Belén Gago
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Luis Santín
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Departamento de Psicobiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Estela Castilla-Ortega
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Departamento de Psicobiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - José Ángel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Zaida Díaz-Cabiale
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
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23
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Khan D, Khan M, Runesson J, Zaben M, Gray WP. GalR3 mediates galanin proliferative effects on postnatal hippocampal precursors. Neuropeptides 2017; 63:14-17. [PMID: 28431685 DOI: 10.1016/j.npep.2017.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 02/23/2017] [Accepted: 04/05/2017] [Indexed: 11/16/2022]
Abstract
Galanin, a neuropeptide co-released from noradrenergic and serotonergic projection neurons to the dentate gyrus, has recently emerged as an important mediator for signaling neuronal activity to the subgranular neurogenic stem cell niche supporting adult hippocampal neurogenesis. Galanin and its receptors appear to play key roles in depression-like behavior, and effects on hippocampal neurogenesis are relevant to pharmacological strategies for treating depression, which in part appear to rely on restoring altered neurogenesis. We previously demonstrated that the GalR2/3 receptor agonist Gal 2-11 is proliferative and proneurogenic for postnatal hippocampal progenitor cells; however, the specific receptor mediation remained to be identified. With the recent availability of M1145 (a specific GalR2 agonist), and SNAP 37889 (GalR3 specific antagonist), we extend our previous studies and show that while M1145 has no proliferative effect, the co-treatment of postnatal rat hippocampal progenitors with Gal 2-11 and SNAP 37889 completely abolished the Gal 2-11 proliferative effects. Taken together, these results clearly demonstrate that GalR3 and not GalR2 is the specific receptor subtype that mediates the proliferative effects of galanin on hippocampal progenitor cells. These results implicate GALR3 in the mediation of galanin neurogenic effects and, potentially, its neurogenic anti-depressant effects.
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Affiliation(s)
- D Khan
- Institute of Psychological Medicine and Clinical Neurosciences, Neurosciences and Mental Health Research Institute NMHRI, Room 3.33, Hadyn Ellis Building, Cardiff CF24 4HQ, United Kingdom
| | - M Khan
- Institute of Psychological Medicine and Clinical Neurosciences, Neurosciences and Mental Health Research Institute NMHRI, Room 3.33, Hadyn Ellis Building, Cardiff CF24 4HQ, United Kingdom
| | - Johan Runesson
- Institute of Psychological Medicine and Clinical Neurosciences, Neurosciences and Mental Health Research Institute NMHRI, Room 3.33, Hadyn Ellis Building, Cardiff CF24 4HQ, United Kingdom
| | - M Zaben
- Institute of Psychological Medicine and Clinical Neurosciences, Neurosciences and Mental Health Research Institute NMHRI, Room 3.33, Hadyn Ellis Building, Cardiff CF24 4HQ, United Kingdom
| | - W P Gray
- Institute of Psychological Medicine and Clinical Neurosciences, Neurosciences and Mental Health Research Institute NMHRI, Room 3.33, Hadyn Ellis Building, Cardiff CF24 4HQ, United Kingdom.
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Flores-Burgess A, Millón C, Gago B, Narváez M, Borroto-Escuela DO, Mengod G, Narváez JA, Fuxe K, Santín L, Díaz-Cabiale Z. Galanin (1-15) enhancement of the behavioral effects of Fluoxetine in the forced swimming test gives a new therapeutic strategy against depression. Neuropharmacology 2017; 118:233-241. [PMID: 28288814 DOI: 10.1016/j.neuropharm.2017.03.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/17/2017] [Accepted: 03/07/2017] [Indexed: 11/16/2022]
Abstract
The pharmacological treatment of major depression is mainly based on drugs elevating serotonergic (5-HT) activity. Specifically, selective 5-HT reuptake inhibitors, including Fluoxetine (FLX), are the most commonly used for treatment of major depression. However, the understanding of the mechanism of action of FLX beyond its effect of elevating 5-HT is limited. The interaction between serotoninergic system and neuropeptides signaling could be a key aspect. We examined the ability of the neuropeptide Galanin(1-15) [GAL(1-15)] to modulate the behavioral effects of FLX in the forced swimming test (FST) and studied feasible molecular mechanisms. The data show that GAL(1-15) enhances the antidepressant-like effects induced by FLX in the FST, and we demonstrate the involvement of GALR1/GALR2 heteroreceptor complex in the GAL(1-15)-mediated effect using in vivo rat models for siRNA GALR1 or GALR2 knockdown. Importantly, 5-HT1A receptors (5HT1A-R) also participate in the GAL(1-15)/FLX interactions since the 5HT1AR antagonist WAY100635 blocked the behavioral effects in the FST induced by the coadministration of GAL(1-15) and FLX. The mechanism underlying GAL(1-15)/FLX interactions affected the binding characteristics as well as the mRNA levels of 5-HT1A-R specifically in the dorsal hippocampus while leaving unaffected mRNA levels and affinity and binding sites of this receptor in the dorsal raphe. The results open up the possibility to use GAL(1-15) as for a combination therapy with FLX as a novel strategy for treatment of depression.
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Affiliation(s)
- Antonio Flores-Burgess
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Carmelo Millón
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Belén Gago
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Manuel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain
| | | | - Guadalupe Mengod
- Department of Neurochemistry and Neuropharmacology, IIBB-CSIC,IDIBAPS,CIBERNED, Barcelona 08036, Spain
| | - José Angel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Luis Santín
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Zaida Díaz-Cabiale
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, Spain.
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Galanin contributes to monoaminergic dysfunction and to dependent neurobehavioral comorbidities of epilepsy. Exp Neurol 2016; 289:64-72. [PMID: 28013000 DOI: 10.1016/j.expneurol.2016.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/23/2016] [Accepted: 12/20/2016] [Indexed: 01/01/2023]
Abstract
Status epilepticus (SE) in rats, along with chronic epilepsy, leads to the development of behavioral impairments resembling depressive disorder and/or attention deficit/hyperactivity disorder (ADHD), thus reflecting respective comorbidities in epilepsy patients. Suppressed neurotransmitter tone in the raphe nucleus (RN)-prefrontal cortex (PFC) serotonergic pathway and in the locus coeruleus (LC)-PFC noradrenergic pathway underlies depressive- and impulsive-like behavioral deficits respectively. We examined possible mechanisms leading to the monoamine dysfunction in brainstem efferents, namely modulatory effects of the neuropeptide galanin on serotonin (5-HT) and norepinephrine (NE) signaling. SE was induced in young adult male Wistar rats by LiCl and pilocarpine. Epileptic rats were categorized vis-à-vis behavioral deficits as not impaired, "depressed" and "impulsive". Depressive- and impulsive-like behaviors were examined in the forced swimming test (FST). The strength of serotonergic transmission in RN-PFC and of noradrenergic transmission in LC-PFC was analyzed using in vivo fast scan cyclic voltammetry. Galanin receptor type 1 (GalR1)/type 2 (GalR2) antagonist M40, and a preferential GalR2 antagonist M871 were administered over 3days locally into either RN or LC by means of ALZET osmotic minipumps connected to locally implanted infusion cannulas. Intra-RN injection of M40 improved serotonergic tone and depressive-like behavior in epileptic "depressed" rats. Intra-LC injection of M40 improved noradrenergic tone and impulsive-like behavior in epileptic "impulsive" rats. The effects of M40 were only observed in impaired subjects. The treatment did not modify neurotransmission and behavior in naïve and epileptic not impaired rats; in "depressed" rats the effects were limited to serotonergic transmission and immobility, while in "impulsive" rats - to noradrenergic transmission and struggling behavior. Intra-RN administration of M871 exacerbated depressive-like behavior, but had no effects on any other of the examined parameters in any category of animals. These findings suggest that endogenous galanin, acting through GalR1 may be involved in the pathophysiology of epilepsy-associated depression and ADHD via inhibiting RN-PFC serotonergic and LC-PFC noradrenergic transmissions respectively.
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Alterations in the neuropeptide galanin system in major depressive disorder involve levels of transcripts, methylation, and peptide. Proc Natl Acad Sci U S A 2016; 113:E8472-E8481. [PMID: 27940914 DOI: 10.1073/pnas.1617824113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Major depressive disorder (MDD) is a substantial burden to patients, families, and society, but many patients cannot be treated adequately. Rodent experiments suggest that the neuropeptide galanin (GAL) and its three G protein-coupled receptors, GAL1-3, are involved in mood regulation. To explore the translational potential of these results, we assessed the transcript levels (by quantitative PCR), DNA methylation status (by bisulfite pyrosequencing), and GAL peptide by RIA of the GAL system in postmortem brains from depressed persons who had committed suicide and controls. Transcripts for all four members were detected and showed marked regional variations, GAL and galanin receptor 1 (GALR1) being most abundant. Striking increases in GAL and GALR3 mRNA levels, especially in the noradrenergic locus coeruleus and the dorsal raphe nucleus, in parallel with decreased DNA methylation, were found in both male and female suicide subjects as compared with controls. In contrast, GAL and GALR3 transcript levels were decreased, GALR1 was increased, and DNA methylation was increased in the dorsolateral prefrontal cortex of male suicide subjects, however, there were no changes in the anterior cingulate cortex. Thus, GAL and its receptor GALR3 are differentially methylated and expressed in brains of MDD subjects in a region- and sex-specific manner. Such an epigenetic modification in GALR3, a hyperpolarizing receptor, might contribute to the dysregulation of noradrenergic and serotonergic neurons implicated in the pathogenesis of MDD. Thus, one may speculate that a GAL3 antagonist could have antidepressant properties by disinhibiting the firing of these neurons, resulting in increased release of noradrenaline and serotonin in forebrain areas involved in mood regulation.
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Webling K, Runesson J, Lang A, Saar I, Kofler B, Langel Ü. Ala 5-galanin (2-11) is a GAL 2R specific galanin analogue. Neuropeptides 2016; 60:75-82. [PMID: 27592409 DOI: 10.1016/j.npep.2016.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 12/18/2022]
Abstract
It is over 30years since the regulatory peptide galanin was discovered by Professor Mutt and co-workers. Galanin exerts its effects by binding to three galanin G-protein coupled receptors, namely GAL1R, GAL2R and GAL3R. Each galanin receptor has a different distribution in the central nervous system and the peripheral nervous system as well as distinctive signaling pathways, which implicates that the receptors are involved in different biological- and pathological effects. The delineation of the galaninergic system is however difficult due to a lack of stable, specific galanin receptor ligands. Herein, a new short GAL2R specific ligand, Ala5-galanin (2-11), is presented. The galanin (2-11) modified analogue Ala5-galanin (2-11) was tested in 125I-galanin competitive binding studies for the three galanin receptors and the G-protein coupled receptor signaling properties was tested by the ability to influence second-messenger molecules like inositol phosphate and cyclic adenosine monophosphate. In addition, two different label-free real-time assays, namely EnSpire® based on an optical biosensor and xCELLigence® based on an electric biosensor, were used for evaluating the signaling properties using cell lines with different levels of receptor expression. Ala5-galanin (2-11) was subsequently found to be a full agonist for GAL2R with more than 375-fold preference for GAL2R compared to both GAL1R and GAL3R. The single amino acid substitution of serine to alanine at position 5 in the short ligand galanin (2-11) resulted in a ligand subsequently unable to bind neither GAL3R nor GAL1R, even at concentrations as high as 0.1mM.
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Affiliation(s)
- Kristin Webling
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden.
| | - Johan Runesson
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden
| | - Andreas Lang
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Indrek Saar
- Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Barbara Kofler
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Ülo Langel
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden; Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
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Pałasz A, Suszka-Świtek A, Filipczyk Ł, Bogus K, Rojczyk E, Worthington J, Krzystanek M, Wiaderkiewicz R. Escitalopram affects spexin expression in the rat hypothalamus, hippocampus and striatum. Pharmacol Rep 2016; 68:1326-1331. [PMID: 27710862 DOI: 10.1016/j.pharep.2016.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/13/2016] [Accepted: 09/01/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND Spexin (SPX) is a recently discovered neuropeptide that exhibits a large spectrum of central and peripheral regulatory activity, especially when considered as a potent anorexigenic factor. It has already been proven that antidepressants, including selective serotonin reuptake inhibitors (SSRI), can modulate peptidergic signaling in various brain structures. Despite these findings, there is so far no information regarding the influence of treatment with the SSRI antidepressant escitalopram on brain SPX expression. METHODS In this current study we measured SPX mRNA and protein expression in the selected brain structures (hypothalamus, hippocampus and striatum) of rats chronically treated with a 10mg/kg dose of escitalopram using quantitative Real-Time PCR and immunohistochemistry. RESULTS Strikingly, long-term (4 week) drug treatment led to the downregulation of SPX expression in the rat hypothalamus. This supports the hypothesis that SPX may be involved in the hypothalamic serotonin-dependent actions of SSRI antidepressants and possibly also in the central mechanism of body mass increase. Conversely, SPX expression increased in the hippocampus and striatum. CONCLUSIONS This is the first report of the effects of a neuropsychiatric medication on SPX expression in animal brain. Our findings shed a new light on the pharmacology of antidepressants and may contribute to a better understanding of the alternative mechanisms responsible for antidepressant action.
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Affiliation(s)
- Artur Pałasz
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland.
| | - Aleksandra Suszka-Świtek
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland
| | - Łukasz Filipczyk
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland
| | - Katarzyna Bogus
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland
| | - Ewa Rojczyk
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland
| | - John Worthington
- Manchester Immunology Group, Faculty of Life Sciences, University of Manchester, Greater Manchester, M13 9PT, UK; Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Marek Krzystanek
- Department and Clinic of Psychiatric Rehabilitation, School of Medicine in Katowice, Medical University of Silesia, Ziolowa 45/47, Katowice 40-635, Poland
| | - Ryszard Wiaderkiewicz
- Department of Histology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18, Katowice 40-752, Poland
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29
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He B, Fang P, Guo L, Shi M, Zhu Y, Xu B, Bo P, Zhang Z. Beneficial effects of neuropeptide galanin on reinstatement of exercise-induced somatic and psychological trauma. J Neurosci Res 2016; 95:1036-1043. [DOI: 10.1002/jnr.23869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 07/01/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Biao He
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention Ministry of Education, School of Physical Education and Health Care, East China Normal University; Shanghai China
| | - Penghua Fang
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Lili Guo
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Mingyi Shi
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Yan Zhu
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Bo Xu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention Ministry of Education, School of Physical Education and Health Care, East China Normal University; Shanghai China
| | - Ping Bo
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Zhenwen Zhang
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
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Wang P, Li H, Barde S, Zhang MD, Sun J, Wang T, Zhang P, Luo H, Wang Y, Yang Y, Wang C, Svenningsson P, Theodorsson E, Hökfelt TGM, Xu ZQD. Depression-like behavior in rat: Involvement of galanin receptor subtype 1 in the ventral periaqueductal gray. Proc Natl Acad Sci U S A 2016; 113:E4726-35. [PMID: 27457954 PMCID: PMC4987783 DOI: 10.1073/pnas.1609198113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The neuropeptide galanin coexists in rat brain with serotonin in the dorsal raphe nucleus and with noradrenaline in the locus coeruleus (LC), and it has been suggested to be involved in depression. We studied rats exposed to chronic mild stress (CMS), a rodent model of depression. As expected, these rats showed several endophenotypes relevant to depression-like behavior compared with controls. All these endophenotypes were normalized after administration of a selective serotonin reuptake inhibitor. The transcripts for galanin and two of its receptors, galanin receptor 1 (GALR1) and GALR2, were analyzed with quantitative real-time PCR using laser capture microdissection in the following brain regions: the hippocampal formation, LC, and ventral periaqueductal gray (vPAG). Only Galr1 mRNA levels were significantly increased, and only in the latter region. After knocking down Galr1 in the vPAG with an siRNA technique, all parameters of the depressive behavioral phenotype were similar to controls. Thus, the depression-like behavior in rats exposed to CMS is likely related to an elevated expression of Galr1 in the vPAG, suggesting that a GALR1 antagonist could have antidepressant effects.
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Affiliation(s)
- Peng Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hui Li
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Ming-Dong Zhang
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden; Division of Molecular Neurobiology, Department of Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Jing Sun
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Tong Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Pan Zhang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hanjiang Luo
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Yongjun Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Yutao Yang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Chuanyue Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Per Svenningsson
- Center for Molecular Medicine, Department of Neurology and Clinical Neuroscience, Karolinska Institutet and Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linkoping University, SE-58183 Linkoping, Sweden
| | - Tomas G M Hökfelt
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden;
| | - Zhi-Qing David Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China;
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31
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Petschner P, Juhasz G, Tamasi V, Adori C, Tothfalusi L, Hökfelt T, Bagdy G. Chronic venlafaxine treatment fails to alter the levels of galanin system transcripts in normal rats. Neuropeptides 2016; 57:65-70. [PMID: 26891823 DOI: 10.1016/j.npep.2016.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/22/2016] [Accepted: 01/31/2016] [Indexed: 11/16/2022]
Abstract
It is widely accepted that efficacy and speed of current antidepressants' therapeutic effect are far from optimal. Thus, there is a need for the development of antidepressants with new mechanisms of action. The neuropeptide galanin and its receptors (GalR1, GalR2 and GalR3) are among the promising targets. However, it is not clear whether or not the galanin system is involved in the antidepressant effect exerted by the currently much used inhibitors of the reuptake of serotonin and/or noradrenaline. To answer this question we administered the selective serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine (40mg/kg/day via osmotic minipumps) to normal rats and examined the levels of the transcripts for galanin and GalR1-3 after a 3-week venlafaxine treatment in the dorsal raphe, hippocampus and frontal cortex. These areas are known to be involved in the effects of antidepressants and in depression itself. Venlafaxine failed to alter the expression of any of the galanin system genes in these areas. Our results show that one of the most efficient, currently used SNRIs does not alter transcript levels of galanin or its three receptors in normal rats. These findings suggest that the pro- and antidepressive-like effects of galanin reported in animal experiments may employ a novel mechanism(s).
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Affiliation(s)
- Peter Petschner
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Gabriella Juhasz
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE-NAP B Genetic Brain Imaging Migraine Research Group, Hungarian Academy of Sciences, Semmelweis University, Hungary
| | - Viola Tamasi
- Department of Genetics-, Cell and Immunobiology, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Csaba Adori
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; Retzius Laboratory, Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177, Stockholm, Sweden
| | - Laszlo Tothfalusi
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Tomas Hökfelt
- Retzius Laboratory, Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177, Stockholm, Sweden
| | - Gyorgy Bagdy
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary.
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32
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Kawa L, Barde S, Arborelius UP, Theodorsson E, Agoston D, Risling M, Hökfelt T. Expression of galanin and its receptors are perturbed in a rodent model of mild, blast-induced traumatic brain injury. Exp Neurol 2016; 279:159-167. [PMID: 26928087 DOI: 10.1016/j.expneurol.2016.02.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 02/22/2016] [Accepted: 02/24/2016] [Indexed: 01/05/2023]
Abstract
The symptomatology, mood and cognitive disturbances seen in post-traumatic stress disorder (PTSD) and mild blast-induced traumatic brain injury (mbTBI) overlap considerably. However the pathological mechanisms underlying the two conditions are currently unknown. The neuropeptide galanin has been suggested to play a role in the development of stress and mood disorders. Here we applied bio- and histochemical methods with the aim to elucidate the nature of any changes in the expression of galanin and its receptors in a rodent model of mbTBI. In situ hybridization and quantitative polymerase chain reaction studies revealed significant, injury-induced changes, in some cases lasting at least for one week, in the mRNA levels of galanin and/or its three receptors, galanin receptor 1-3 (GalR1-3). Such changes were seen in several forebrain regions, and the locus coeruleus. In the ventral periaqueductal gray GalR1 mRNA levels were increased, while GalR2 were decreased. Analysis of galanin peptide levels using radioimmunoassay demonstrated an increase in several brain regions including the locus coeruleus, dorsal hippocampal formation and amygdala. These findings suggest a role for the galanin system in the endogenous response to mbTBI, and that pharmacological studies of the effects of activation or inhibition of different galanin receptors in combination with functional assays of behavioral recovery may reveal promising targets for new therapeutic strategies in mbTBI.
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Affiliation(s)
- Lizan Kawa
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden.
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden
| | - Ulf P Arborelius
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry, Linköping University, Linköping, Sweden
| | - Denes Agoston
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden; Department of Anatomy, Physiology and Genetics, The Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814, United States
| | - Mårten Risling
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden.
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE 171 77 Stockholm, Sweden
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Galanin (1-15) enhances the antidepressant effects of the 5-HT1A receptor agonist 8-OH-DPAT: involvement of the raphe-hippocampal 5-HT neuron system. Brain Struct Funct 2016; 221:4491-4504. [PMID: 26792005 DOI: 10.1007/s00429-015-1180-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
Abstract
Galanin N-terminal fragment (1-15) [GAL(1-15)] is associated with depression-related and anxiogenic-like effects in rats. In this study, we analyzed the ability of GAL(1-15) to modulate 5-HT1A receptors (5-HT1AR), a key receptor in depression. GAL(1-15) enhanced the antidepressant effects induced by the 5-HT1AR agonist 8-OH-DPAT in the forced swimming test. These effects were stronger than the ones induced by Galanin (GAL). This action involved interactions at receptor level since GAL(1-15) affected the binding characteristics and the mRNA levels of 5-HT1AR in the dorsal hippocampus and dorsal raphe. The involvement of the GALR2 was demonstrated with the GALR2 antagonist M871. Proximity ligation assay experiments indicated that 5-HT1AR are in close proximity with GALR1 and GALR2 in both regions and in raphe RN33B cells. The current results indicate that GAL(1-15) enhances the antidepressant effects induced by 8-OH-DPAT acting on 5-HT1AR operating as postjunctional or as autoreceptors. These results may give the basis for the development of drugs targeting potential GALR1-GALR2-5-HT1AR heteroreceptor complexes linked to the raphe-hippocampal 5-HT neurons for the treatment of depression.
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Weinshenker D, Holmes PV. Regulation of neurological and neuropsychiatric phenotypes by locus coeruleus-derived galanin. Brain Res 2015; 1641:320-37. [PMID: 26607256 DOI: 10.1016/j.brainres.2015.11.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/27/2015] [Accepted: 11/12/2015] [Indexed: 12/28/2022]
Abstract
Decades of research confirm that noradrenergic locus coeruleus (LC) neurons are essential for arousal, attention, motivation, and stress responses. While most studies on LC transmission focused unsurprisingly on norepinephrine (NE), adrenergic signaling cannot account for all the consequences of LC activation. Galanin coexists with NE in the vast majority of LC neurons, yet the precise function of this neuropeptide has proved to be surprisingly elusive given our solid understanding of the LC system. To elucidate the contribution of galanin to LC physiology, here we briefly summarize the nature of stimuli that drive LC activity from a neuroanatomical perspective. We go on to describe the LC pathways in which galanin most likely exerts its effects on behavior, with a focus on addiction, depression, epilepsy, stress, and Alzheimer׳s disease. We propose a model in which LC-derived galanin has two distinct functions: as a neuromodulator, primarily acting via the galanin 1 receptor (GAL1), and as a trophic factor, primarily acting via galanin receptor 2 (GAL2). Finally, we discuss how the recent advances in neuropeptide detection, optogenetics and chemical genetics, and galanin receptor pharmacology can be harnessed to identify the roles of LC-derived galanin definitively. This article is part of a Special Issue entitled SI: Noradrenergic System.
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Affiliation(s)
- David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, 615 Michael St., Whitehead 301, Atlanta, GA 30322, USA.
| | - Philip V Holmes
- Neuroscience Program, Biomedical and Health Sciences Institute and Psychology Department, University of Georgia, Athens, GA 30602, USA.
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Ogbonmwan YE, Sciolino NR, Groves-Chapman JL, Freeman KG, Schroeder JP, Edwards GL, Holmes PV, Weinshenker D. The galanin receptor agonist, galnon, attenuates cocaine-induced reinstatement and dopamine overflow in the frontal cortex. Addict Biol 2015; 20:701-13. [PMID: 25053279 PMCID: PMC4305031 DOI: 10.1111/adb.12166] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Relapse represents one of the most significant problems in the long-term treatment of drug addiction. Cocaine blocks plasma membrane monoamine transporters and increases dopamine (DA) overflow in the brain, and DA is critical for the motivational and primary reinforcing effects of the drug as well as cocaine-primed reinstatement of cocaine seeking in rats, a model of relapse. Thus, modulators of the DA system may be effective for the treatment of cocaine dependence. The endogenous neuropeptide galanin inhibits DA transmission, and both galanin and the synthetic galanin receptor agonist, galnon, interfere with some rewarding properties of cocaine. The purpose of this study was to further assess the effects of galnon on cocaine-induced behaviors and neurochemistry in rats. We found that galnon attenuated cocaine-induced motor activity, reinstatement and DA overflow in the frontal cortex at a dose that did not reduce baseline motor activity, stable self-administration of cocaine, baseline extracellular DA levels or cocaine-induced DA overflow in the nucleus accumbens (NAc). Similar to cocaine, galnon had no effect on stable food self-administration but reduced food-primed reinstatement. These results indicate that galnon can diminish cocaine-induced hyperactivity and relapse-like behavior, possibly in part by modulating DA transmission in the frontal cortex.
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Affiliation(s)
- Yvonne E. Ogbonmwan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Natale R. Sciolino
- Graduate Program in Neuroscience, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602
| | - Jessica L. Groves-Chapman
- Graduate Program in Neuroscience, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602
| | - Kimberly G. Freeman
- Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602
| | - Jason P. Schroeder
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Gaylen L. Edwards
- Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602
| | - Philip V. Holmes
- Graduate Program in Neuroscience, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602
- Department of Psychology, University of Georgia, Athens, GA 30602
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
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Millón C, Flores-Burgess A, Narváez M, Borroto-Escuela DO, Santín L, Parrado C, Narváez JA, Fuxe K, Díaz-Cabiale Z. A role for galanin N-terminal fragment (1-15) in anxiety- and depression-related behaviors in rats. Int J Neuropsychopharmacol 2015; 18:pyu064. [PMID: 25522404 PMCID: PMC4360234 DOI: 10.1093/ijnp/pyu064] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Galanin (GAL) plays a role in mood regulation. In this study we analyzed the action of the active N-terminal fragment [GAL(1-15)] in anxiety- and depression-related behavioral tests in rats. METHODS The effect of GAL(1-15) was analyzed in the forced swimming test, tail suspension test, open field test, and light/dark test. The proximity of GAL1 and GAL2 receptors was examined with the proximity ligation assay (PLA). We tested the GAL receptors involved in GAL(1-15) effects with the GAL2 receptor antagonist M871 and with an in vivo model of siRNA GAL2 receptor knockdown or siRNA GAL1 receptor knockdown rats. The effects of GAL(1-15) were also studied in the cell line RN33B. RESULTS GAL(1-15) induced strong depression-like and anxiogenic-like effects in all the tests. These effects were stronger than the ones induced by GAL. The involvement of the GAL2 receptor was demonstrated with M871 and with the siRNA GAL2 receptor knockdown rats. The PLA indicated the possible existence of GAL1 and GAL2 heteroreceptor complexes in the dorsal hippocampus and especially in the dorsal raphe nucleus. In the siRNA GAL1 receptor knockdown rats the behavioral actions of GAL(1-15) disappeared, and in the siRNA GAL2 receptor knockdown rats the reductions of the behavioral actions of GAL(1-15) was linked to a disappearance of PLA. In the cell line RN33B, GAL(1-15) decreased 5-HT immunoreactivity more strongly than GAL. CONCLUSIONS Our results indicate that GAL(1-15) exerts strong depression-related and anxiogenic-like effects and may give the basis for the development of drugs targeting GAL1 and GAL2 heteroreceptor complexes in the raphe-limbic system for the treatment of depression and anxiety.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Zaida Díaz-Cabiale
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Campus de Teatinos s/n, 29071 Málaga, España (PhD Millón, Flores-Burgess, M Narváez, Parrado, JA Narváez, and Díaz-Cabiale); Department of Neuroscience, Karolinska Institute, Stockholm, Sweden (PhD Borroto-Escuela and Fuxe); Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Campus de Teatinos s/n, 29071 Málaga, España (PhD Santín).
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Sciolino NR, Smith JM, Stranahan AM, Freeman KG, Edwards GL, Weinshenker D, Holmes PV. Galanin mediates features of neural and behavioral stress resilience afforded by exercise. Neuropharmacology 2015; 89:255-64. [PMID: 25301278 PMCID: PMC4250306 DOI: 10.1016/j.neuropharm.2014.09.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/23/2014] [Accepted: 09/28/2014] [Indexed: 12/15/2022]
Abstract
Exercise promotes resilience to stress and increases galanin in the locus coeruleus (LC), but the question of whether changes in galanin signaling mediate the stress-buffering effects of exercise has never been addressed. To test the contributions of galanin to stress resilience, male Sprague Dawley rats received intracerebroventricular (ICV) cannulation for drug delivery and frontocortical cannulation for microdialysis, and were housed with or without a running wheel for 21d. Rats were acutely injected with vehicle or the galanin receptor antagonist M40 and exposed to a single session of either footshock or no stress. Other groups received galanin, the galanin receptor antagonist M40, or vehicle chronically for 21d prior to the stress session. Microdialysis sampling occurred during stress exposure and anxiety-related behavior was measured on the following day in the elevated plus maze. Dendritic spines were visualized by Golgi impregnation in medial prefrontal cortex (mPFC) pyramidal neurons and quantified. Exercise increased galanin levels in the LC. Under non-stressed conditions, anxiety-related behavior and dopamine levels were comparable between exercised and sedentary rats. In contrast, exposure to stress reduced open arm exploration in sedentary rats but not in exercise rats or those treated chronically with ICV galanin, indicating improved resilience. Both exercise and chronic, ICV galanin prevented the increased dopamine overflow and loss of dendritic spines observed after stress in sedentary rats. Chronic, but not acute M40 administration blocked the resilience-promoting effects of exercise. The results indicate that increased galanin levels promote features of resilience at both behavioral and neural levels.
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Affiliation(s)
- N R Sciolino
- Neuroscience Program, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602, USA.
| | - J M Smith
- Neuroscience Program, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602, USA.
| | - A M Stranahan
- Physiology Department, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA.
| | - K G Freeman
- Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA.
| | - G L Edwards
- Neuroscience Program, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602, USA; Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA.
| | - D Weinshenker
- Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - P V Holmes
- Neuroscience Program, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602, USA; Psychology Department, University of Georgia, Athens, GA 30602, USA.
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Wang YJ, Yang YT, Li H, Liu PZ, Wang CY, Xu ZQD. Plasma galanin is a biomarker for severity of major depressive disorder. Int J Psychiatry Med 2015; 48:109-19. [PMID: 25377152 DOI: 10.2190/pm.48.2.d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE This study investigated the association between plasma galanin level and depression severity. METHODS The severity of depression symptoms of 79 patients with major depressive disorder (MDD; 52 women and 27 men, 71 patients in onset, 8 in remission) was assessed using the 17-item Hamilton Depression Rating Scale. Venous fasting blood samples (5 mL) were taken from the 79 MDD patients, 35 healthy siblings, and 19 healthy controls, and plasma samples were prepared. Galanin levels in the plasma were measured by radioimmunoassay. RESULTS Plasma galanin in MDD patients was significantly higher than that of remission patients, healthy siblings, or healthy controls (P < 0.05) There was no significant difference between the healthy sibling and healthy control groups (P = 0.924). Plasma galanin of remission patients was also significantly higher than that of healthy controls (P < 0.05). There was no significant correlation between age and galanin levels in the 79 patients (r = 0.053, P = 0.646), nor was there a correlation between age and galanin levels when patients were stratified by gender (P > 0.05). There was a significant positive correlation between plasma galanin levels and depression severity in women MDD patients (r = 0.329, df = 42, P = 0.020), but not in men patients. CONCLUSIONS Plasma galanin levels may be an important biomarker for depression severity, especially in female patients.
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Affiliation(s)
- Yong-Jun Wang
- Tianjin AnDing Hospital, Capital Medical University, Beijing Tsinghua University, Beijing
| | - Yu-Tao Yang
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University
| | - Hui Li
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University
| | | | - Chuan-Yue Wang
- Beijing Key Laboratory of Mental Disorders, Capital Medical University
| | - Zhi-Qing David Xu
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University
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Alteration of behavioral changes and hippocampus galanin expression in chronic unpredictable mild stress-induced depression rats and effect of electroacupuncture treatment. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:179796. [PMID: 25530777 PMCID: PMC4233667 DOI: 10.1155/2014/179796] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/15/2014] [Accepted: 09/17/2014] [Indexed: 11/26/2022]
Abstract
To explore new noninvasive treatment options for depression, this study investigated the effects of electric acupuncture (EA) for depression rat models. Depression in rats was induced by unpredictable chronic mild stress (UCMS) combined with isolation for 21 days. Eighteen male Sprague-Dawley rats were randomly assigned into three groups: control, model, and EA groups. Rats were treated by EA once daily for 21 days. The results showed that body weight and sucrose consumption were significantly increased in EA group than in the model group. The crossing numbers and rearing numbers in the open field test significantly decreased in the model group but not in the EA group. And EA treatments upregulated levels of hippocampus galanin (Gal) in UCMS rats back to relative normal levels. The present study suggested that EA had antidepressant effects on UCMS model rats. The potential antidepressant effect may be related to upregulating Gal expression in hippocampus.
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40
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Jakob S, Schraut KG, Schmitt AG, Scholz CJ, Ortega G, Steinbusch HW, Lesch KP, van den Hove DLA. Differential effects of prenatal stress in female 5-HTT-deficient mice: towards molecular mechanisms of resilience. Dev Neurosci 2014; 36:454-64. [PMID: 25195605 DOI: 10.1159/000363695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 05/13/2014] [Indexed: 11/19/2022] Open
Abstract
Prenatal stress (PS) exposure is known to increase the risk of developing emotional disorders like major depression in later life. However, some individuals do not succumb to adversity following developmental stress exposure, a phenomenon referred to as resilience. To date, the molecular mechanisms explaining why some subjects are vulnerable and others more resilient to PS are far from understood. Recently, we have shown that the serotonin transporter (5-HTT) gene may play a modulating role in rendering individuals susceptible or resilient to PS. However, it is not clear which molecular players are mediating the interaction between PS and the 5-Htt genotype in the context of vulnerability and resilience to PS. For this purpose, we performed a microarray study with the help of Affymetrix GeneChip® Mouse Genome 430 2.0 Array, in which we separated wild-type and heterozygous 5-Htt-deficient (5-Htt+/-) PS offspring into susceptible and resilient offspring according to their performance in the forced swim test. Performance-oriented LIMMA analysis on the mRNA expression microarray data was followed by subsequent Spearman's correlation analysis linking the individual qRT-PCR mRNA expression data to various anxiety- and depression-related behavioral and neuroendocrine measures. Results indicate that, amongst others, Fos-induced growth factor (Figf), galanin receptor 3 (Galr3), growth hormone (Gh) and prolactin (Prl) were differentially expressed specifically in resilient offspring when compared to controls, and that the hippocampal expression of these genes showed several strong correlations with various measures of the hypothalamus-pituitary-adrenal axis (re)activity. In conclusion, there seems to be an intricate interplay between the expression of Figf, Galr3, Gh and Prl and neuroendocrine regulation, which may be critical in mediating resilience to PS exposure. More insight into the exact role of these molecular players may significantly enhance the development of new treatment strategies for stress-related emotional disorders.
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Affiliation(s)
- Sissi Jakob
- Department of Neuroscience, School for Mental Health and Neuroscience (MHENS), Maastricht University, Maastricht, The Netherlands
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Dhurandhar EJ, Keith SW. The aetiology of obesity beyond eating more and exercising less. Best Pract Res Clin Gastroenterol 2014; 28:533-44. [PMID: 25194173 DOI: 10.1016/j.bpg.2014.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 06/06/2014] [Accepted: 07/05/2014] [Indexed: 01/31/2023]
Abstract
Although recent increases in availability of energy dense, processed foods and reductions in institutionally driven physical activity have created an environment that is permissible for obesity to occur, several other factors may contribute to the development of obesity in this context. We review evidence for eleven such factors: endocrine disruptors, intrauterine effects, epigenetics, maternal age, differential fecundity and assortative mating by body mass index, microorganisms, reduction in variability of ambient temperatures, smoking cessation, sleep debt, and pharmaceutical iatrogenesis. Evidence for the role of endocrine disruptors, microorganisms, ambient temperatures, sleep and reproductive factors is accumulating, but additional research is needed to confirm the causative role of these factors in human obesity. However, the role of certain pharmaceuticals and smoking cessation in development of human obesity is clear. Practice points for consideration and future research needed are highlighted for each factor.
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Affiliation(s)
- Emily J Dhurandhar
- Department of Health Behavior, Office of Energetics, Nutrition Obesity Research Center, University of Alabama at Birmingham, 1665 University Blvd, RPHB 227J, Birmingham, AL 35205, USA.
| | - Scott W Keith
- Department of Pharmacology and Experimental Therapeutics, Division of Biostatistics, Thomas Jefferson University, 1015 Chestnut St., Suite M100, Phildelphia, PA 19107, USA.
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Wang M, Chen Q, Li M, Zhou W, Ma T, Wang Y, Gu S. Alarin-induced antidepressant-like effects and their relationship with hypothalamus-pituitary-adrenal axis activity and brain derived neurotrophic factor levels in mice. Peptides 2014; 56:163-72. [PMID: 24768903 DOI: 10.1016/j.peptides.2014.04.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/11/2014] [Accepted: 04/11/2014] [Indexed: 12/22/2022]
Abstract
Alarin is a newly identified member of the galanin family of peptides. Galanin has been shown to exert regulatory effects on depression. Similar to galanin in distribution, alarin is also expressed in the medial amygdala and hypothalamus, i.e., regions interrelated with depression. However, it remains a puzzle whether alarin is involved in depression. Accordingly, we established the depression-like mouse model using behavioral tests to ascertain the possible involvement of alarin, with fluoxetine as a positive control. With the positive antidepressant-like effects of alarin, we further examined its relationship to HPA axis activity and brain-derived neurotrophic factor (BDNF) levels in different brain areas in a chronic unpredictable mild stress (CUMS) paradigm. In the acute studies, alarin produced a dose-related reduction in the immobility duration in tail suspension test (TST) in mice. In the open-field test, intracerebroventricular (i.c.v.) injection of alarin (1.0 nmol) did not impair locomotion or motor coordination in the treated mice. In the CUMS paradigm, alarin administration (1.0 nmol, i.c.v.) significantly improved murine behaviors (FST and locomotor activity), which was associated with a decrease in corticotropin-releasing hormone (CRH) mRNA levels in the hypothalamus, as well as a decline in serum levels of CRH, adrenocorticotropic hormone (ACTH) and corticosterone (CORT), all of which are key hormones of the HPA axis. Furthermore, alarin upregulated BDNF mRNA levels in the prefrontal cortex and hippocampus. These findings suggest that alarin may potentiate the development of new antidepressants, which would be further secured with the identification of its receptor(s).
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Affiliation(s)
- Ming Wang
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Qian Chen
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Mei Li
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Wei Zhou
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Tengfei Ma
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Yun Wang
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China
| | - Shuling Gu
- Department of Pharmacology, Xuzhou Medical College, Xuzhou, Jiangsu 221004, China.
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The potential antidepressant and antidiabetic effects of galanin system. Pharmacol Biochem Behav 2014; 120:82-7. [DOI: 10.1016/j.pbb.2014.02.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/17/2014] [Accepted: 02/22/2014] [Indexed: 11/17/2022]
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Abstract
The neuropeptide galanin (GAL) is widely distributed in the central and peripheral nervous systems. It is a modulator of various physiological and pathological processes, and it mediates its effects via three G protein-coupled receptors (GAL1-3 receptors). A role for GAL as a modulator of mood and anxiety was suggested, because GAL and its receptors are highly expressed in limbic brain structures of rodents. In recent years, numerous studies of animal models have suggested an involvement of GAL and GAL1 and GAL2 receptors in anxiety- and depression-related behavior. However, to date, there is sparse literature implicating GAL3 receptors in behavioral functions. Therefore, we studied the behavior of GAL3 receptor-deficient (GAL3-KO) mice to elucidate whether GAL3 receptors are involved in mediating behavior-associated actions of GAL. The GAL3-KO mouse line exhibited normal breeding and physical development. In addition to behavioral tests, phenotypic characterization included analysis of hematology, amino acid profiles, metabolism, and sudomotor function. In contrast to WT littermates, male GAL3-KO mice exhibited an anxiety-like phenotype in the elevated plus maze, open field, and light/dark box tests, and they were less socially affiliated than WT animals to a stranger mouse in a social interaction test. In conclusion, our data suggest involvement of GAL3 receptors in GAL-mediated effects on mood, anxiety, and behavior, making it a possible target for alternative treatment strategies for mood disorders.
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Kormos V, Gaszner B. Role of neuropeptides in anxiety, stress, and depression: from animals to humans. Neuropeptides 2013; 47:401-19. [PMID: 24210138 DOI: 10.1016/j.npep.2013.10.014] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/07/2013] [Accepted: 10/09/2013] [Indexed: 12/11/2022]
Abstract
Major depression, with its strikingly high prevalence, is the most common cause of disability in communities of Western type, according to data of the World Health Organization. Stress-related mood disorders, besides their deleterious effects on the patient itself, also challenge the healthcare systems with their great social and economic impact. Our knowledge on the neurobiology of these conditions is less than sufficient as exemplified by the high proportion of patients who do not respond to currently available medications targeting monoaminergic systems. The search for new therapeutical strategies became therefore a "hot topic" in neuroscience, and there is a large body of evidence suggesting that brain neuropeptides not only participate is stress physiology, but they may also have clinical relevance. Based on data obtained in animal studies, neuropeptides and their receptors might be targeted by new candidate neuropharmacons with the hope that they will become important and effective tools in the management of stress related mood disorders. In this review, we attempt to summarize the latest evidence obtained using animal models for mood disorders, genetically modified rodent models for anxiety and depression, and we will pay some attention to previously published clinical data on corticotropin releasing factor, urocortin 1, urocortin 2, urocortin 3, arginine-vasopressin, neuropeptide Y, pituitary adenylate-cyclase activating polypeptide, neuropeptide S, oxytocin, substance P and galanin fields of stress research.
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Affiliation(s)
- Viktória Kormos
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary; Molecular Pharmacology Research Group, János Szentágothai Research Center, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary; Department of Anatomy, Faculty of Medicine, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
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Nikitidou L, Torp M, Fjord-Larsen L, Kusk P, Wahlberg LU, Kokaia M. Encapsulated galanin-producing cells attenuate focal epileptic seizures in the hippocampus. Epilepsia 2013; 55:167-74. [DOI: 10.1111/epi.12470] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Litsa Nikitidou
- Experimental Epilepsy Group; Wallenberg Neuroscience Center; BMC A-11; Lund University Hospital; Lund Sweden
| | | | | | | | | | - Mérab Kokaia
- Experimental Epilepsy Group; Wallenberg Neuroscience Center; BMC A-11; Lund University Hospital; Lund Sweden
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Zhao X, Yun K, Seese RR, Wang Z. Galnon facilitates extinction of morphine-conditioned place preference but also potentiates the consolidation process. PLoS One 2013; 8:e76395. [PMID: 24146862 PMCID: PMC3795750 DOI: 10.1371/journal.pone.0076395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/30/2013] [Indexed: 12/17/2022] Open
Abstract
Learning and memory systems are intimately involved in drug addiction. Previous studies suggest that galanin, a neuropeptide that binds G-protein coupled receptors, plays essential roles in the encoding of memory. In the present study, we tested the function of galnon, a galanin receptor 1 and 2 agonist, in reward-associated memory, using conditioned place preference (CPP), a widely used paradigm in drug-associated memory. Either before or following CPP-inducing morphine administration, galnon was injected at four different time points to test the effects of galanin activation on different reward-associated memory processes: 15 min before CPP training (acquisition), immediately after CPP training (consolidation), 15 min before the post-conditioning test (retrieval), and multiple injection after post-tests (reconsolidation and extinction). Galnon enhanced consolidation and extinction processes of morphine-induced CPP memory, but the compound had no effect on acquisition, retrieval, or reconsolidation processes. Our findings demonstrate that a galanin receptor 1 and 2 agonist, galnon, may be used as a viable compound to treat drug addiction by facilitating memory extinction process.
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Affiliation(s)
- Xiaojie Zhao
- Department of Forensic Science, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, PR China
- Department of Forensic Medicine, Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Keming Yun
- School of Forensic Medicine, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Ronald R. Seese
- Department of Anatomy & Neurobiology, University of California Irvine, School of Medicine, Irvine, California, United States of America
| | - Zhenyuan Wang
- Department of Forensic Science, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, PR China
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48
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The role of galanin system in modulating depression, anxiety, and addiction-like behaviors after chronic restraint stress. Neuroscience 2013; 246:82-93. [DOI: 10.1016/j.neuroscience.2013.04.046] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 11/21/2022]
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49
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Saar I, Lahe J, Langel K, Runesson J, Webling K, Järv J, Rytkönen J, Närvänen A, Bartfai T, Kurrikoff K, Langel Ü. Novel systemically active galanin receptor 2 ligands in depression-like behavior. J Neurochem 2013; 127:114-23. [PMID: 23600864 DOI: 10.1111/jnc.12274] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/31/2013] [Accepted: 03/31/2013] [Indexed: 11/30/2022]
Abstract
Neuropeptide galanin and its three G-protein coupled receptors, galanin receptor type 1-galanin receptor type 3 (GalR1-GalR3), are involved in the regulation of numerous physiological and disease processes, and thus represent tremendous potential in neuroscience research and novel drug lead development. One of the areas where galanin is involved is depression. Previous studies have suggested that activation of GalR2 leads to attenuation of depression-like behavior. Unfortunately, lack of in vivo usable subtype specific ligands hinders testing the role of galanin in depression mechanisms. In this article, we utilize an approach of increasing in vivo usability of peptide-based ligands, acting upon CNS. Thus, we have synthesized a series of novel systemically active galanin analogs, with modest preferential binding toward GalR2. We have shown that specific chemical modifications to the galanin backbone increase brain levels upon i.v. injection of the peptides. Several of the new peptides, similar to a common clinically used antidepressant medication imipramine, exerted antidepressant-like effect in forced swim test, a mouse model of depression, at a surprisingly low dose range (< 0.5 mg/kg). We chose one of the peptides, J18, for more thorough study, and showed its efficacy also in another mouse depression model (tail suspension test), and demonstrated that its antidepressant-like effect upon i.v. administration can be blocked by i.c.v. galanin receptor antagonist M35. The effect of the J18 was also abolished in GalR2KO animals. All this suggests that systemically administered peptide analog J18 exerts its biological effect through activation of GalR2 in the brain. The novel galanin analogs represent potential drug leads and a novel pharmaceutical intervention for depression.
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Affiliation(s)
- Indrek Saar
- Institute of Technology, University of Tartu, Tartu, Estonia; Department of Neurochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden
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50
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Maejima T, Masseck OA, Mark MD, Herlitze S. Modulation of firing and synaptic transmission of serotonergic neurons by intrinsic G protein-coupled receptors and ion channels. Front Integr Neurosci 2013; 7:40. [PMID: 23734105 PMCID: PMC3661940 DOI: 10.3389/fnint.2013.00040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/03/2013] [Indexed: 11/13/2022] Open
Abstract
Serotonergic neurons project to virtually all regions of the central nervous system and are consequently involved in many critical physiological functions such as mood, sexual behavior, feeding, sleep/wake cycle, memory, cognition, blood pressure regulation, breathing, and reproductive success. Therefore, serotonin release and serotonergic neuronal activity have to be precisely controlled and modulated by interacting brain circuits to adapt to specific emotional and environmental states. We will review the current knowledge about G protein-coupled receptors and ion channels involved in the regulation of serotonergic system, how their regulation is modulating the intrinsic activity of serotonergic neurons and its transmitter release and will discuss the latest methods for controlling the modulation of serotonin release and intracellular signaling in serotonergic neurons in vitro and in vivo.
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Affiliation(s)
- Takashi Maejima
- Department of Zoology and Neurobiology, Ruhr-University Bochum Bochum, Germany
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