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Palus K, Chmielewska-Krzesińska M, Jana B, Całka J. Glyphosate-induced changes in the expression of galanin and GALR1, GALR2 and GALR3 receptors in the porcine small intestine wall. Sci Rep 2024; 14:8905. [PMID: 38632282 PMCID: PMC11024183 DOI: 10.1038/s41598-024-59581-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 04/12/2024] [Indexed: 04/19/2024] Open
Abstract
Glyphosate is the active ingredient of glyphosate-based herbicides and the most commonly used pesticide in the world. The goal of the present study was to verify whether low doses of glyphosate (equivalent to the environmental exposure) evoke changes in galanin expression in intramural neurons in the small intestine in pigs and to quantitatively determine changes in the level of galanin receptor encoding mRNA (GALR1, GALR2, GALR3) in the small intestine wall. The experiment was conducted on 15 sexually immature gilts divided into three study groups: control (C)-animals receiving empty gelatin capsules; experimental 1 (G1)-animals receiving a low dose of glyphosate (0.05 mg/kg b.w./day); experimental 2 (G2)-animals receiving a higher dose of glyphosate (0.5 mg/kg b.w./day) orally in gelatine capsules for 28 days. Glyphosate ingestion led to an increase in the number of GAL-like immunoreactive intramural neurons in the porcine small intestine. The results of RT-PCR showed a significant increase in the expression of mRNA, which encodes the GAL-receptors in the ileum, a decreased expression in the duodenum and no significant changes in the jejunum. Additionally, intoxication with glyphosate increased the expression of SOD2-encoding mRNA in the duodenum and decreased it in the jejunum and ileum, but it did not affect SOD1 expression. The results suggest that it may be a consequence of the cytotoxic and/or neurotoxic properties of glyphosate and/or its ability to induce oxidative stress.
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MESH Headings
- Animals
- Female
- Galanin/metabolism
- Glyphosate/metabolism
- Glyphosate/toxicity
- Intestine, Small/drug effects
- Intestine, Small/metabolism
- Receptor, Galanin, Type 2/drug effects
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- RNA, Messenger/metabolism
- Sus scrofa/genetics
- Swine
- Receptor, Galanin, Type 1/drug effects
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 3/drug effects
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Herbicides/toxicity
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Affiliation(s)
- Katarzyna Palus
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719, Olsztyn, Poland.
| | - Małgorzata Chmielewska-Krzesińska
- Department of Pathophysiology, Forensic Veterinary Medicine and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland
| | - Barbara Jana
- Division of Reproductive Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-078, Olsztyn, Poland
| | - Jarosław Całka
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719, Olsztyn, Poland
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2
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Beltran-Casanueva R, Hernández-García A, Serrano-Castro PJ, Sánchez-Pérez JA, Barbancho-Fernández MA, García-Casares N, Fuxe K, Borroto-Escuela DO, Narváez M. Long-term enhancements in antidepressant efficacy and neurogenesis: Effects of intranasal co-administration of neuropeptide Y 1 receptor (NPY1R) and galanin receptor 2 (GALR2) agonists in the ventral hippocampus. FASEB J 2024; 38:e23595. [PMID: 38572811 DOI: 10.1096/fj.202400087r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/27/2024] [Accepted: 03/25/2024] [Indexed: 04/05/2024]
Abstract
This study evaluates the sustained antidepressant-like effects and neurogenic potential of a 3-day intranasal co-administration regimen of galanin receptor 2 (GALR2) agonist M1145 and neuropeptide Y Y1 receptor (NPY1R) agonist [Leu31, Pro34]NPY in the ventral hippocampus of adult rats, with outcomes analyzed 3 weeks post-treatment. Utilizing the forced swimming test (FST), we found that this co-administration significantly enhances antidepressant-like behaviors, an effect neutralized by the GALR2 antagonist M871, highlighting the synergistic potential of these neuropeptides in modulating mood-related behaviors. In situ proximity ligation assay (PLA) indicated a significant increase in GALR2/NPYY1R heteroreceptor complexes in the ventral hippocampal dentate gyrus, suggesting a molecular basis for the behavioral outcomes observed. Moreover, proliferating cell nuclear antigen (PCNA) immunolabeling revealed increased cell proliferation in the subgranular zone of the dentate gyrus, specifically in neuroblasts as evidenced by co-labeling with doublecortin (DCX), without affecting quiescent neural progenitors or astrocytes. The study also noted a significant uptick in the number of DCX-positive cells and alterations in dendritic morphology in the ventral hippocampus, indicative of enhanced neuronal differentiation and maturation. These morphological changes highlight the potential of these agonists to facilitate the functional integration of new neurons into existing neural circuits. By demonstrating the long-lasting effects of a brief, 3-day intranasal administration of GALR2 and NPY1R agonists, our findings contribute significantly to the understanding of neuropeptide-mediated neuroplasticity and herald novel therapeutic strategies for the treatment of depression and related mood disorders, emphasizing the therapeutic promise of targeting neurogenesis and neuronal maturation processes.
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Affiliation(s)
- Rasiel Beltran-Casanueva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Aracelis Hernández-García
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Departamento de Docencia e Investigación, Universidad de Ciencias Médicas de Holguín, Hospital Pedíatrico Universitario Octavio de la Concepción de la Pedraja, Holguín, Cuba
| | - Pedro Jesús Serrano-Castro
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
| | - Jose Andrés Sánchez-Pérez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Psychiatry, Hospital Universitario Virgen de la Victoria, Málaga, Spain
| | | | - Natalia García-Casares
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Manuel Narváez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
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3
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Gallagher DM, O'Harte FPM, Irwin N. An update on galanin and spexin and their potential for the treatment of type 2 diabetes and related metabolic disorders. Peptides 2024; 171:171096. [PMID: 37714335 DOI: 10.1016/j.peptides.2023.171096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/04/2023] [Accepted: 09/11/2023] [Indexed: 09/17/2023]
Abstract
Spexin (SPX) and galanin (GAL) are two neuropeptides widely expressed in the central nervous system as well as within peripheral tissues in humans and other species. SPX and GAL mediate their biological actions through binding and activation of galanin receptors (GALR), namely GALR1, GALR2 and GLAR3. GAL appears to trigger all three galanin receptors, whereas SPX interacts more specifically with GALR2 and GLAR3. Whilst the biological effects of GAL have been well-described over the years, in-depth knowledge of physiological action profile of SPX is still in its preliminary stages. However, it is recognised that both peptides play a significant role in modulating overall energy homeostasis, suggesting possible therapeutically exploitable benefits in diseases such as obesity and type 2 diabetes mellitus. Accordingly, although both peptides activate GALR's, it appears GAL may be more useful for the treatment of eating disorders such as anorexia and bulimia, whereas SPX may find therapeutic application for obesity and obesity-driven forms of diabetes. This short narrative review aims to provide an up-to-date account of SPX and GAL biology together with putative approaches on exploiting these peptides for the treatment of metabolic disorders.
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Affiliation(s)
- Daniel M Gallagher
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK
| | - Finbarr P M O'Harte
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK
| | - Nigel Irwin
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK.
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4
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Kiezun J, Kiezun M, Krazinski BE, Paukszto L, Koprowicz-Wielguszewska A, Kmiec Z, Godlewski J. Galanin Receptors (GALR1, GALR2, and GALR3) Immunoexpression in Enteric Plexuses of Colorectal Cancer Patients: Correlation with the Clinico-Pathological Parameters. Biomolecules 2022; 12:biom12121769. [PMID: 36551197 PMCID: PMC9775555 DOI: 10.3390/biom12121769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022] Open
Abstract
Galanin (GAL) is an important neurotransmitter released by the enteric nervous system (ENS) neurons located in the muscularis externa and submucosa enteric plexuses that acts by binding to GAL receptors 1, 2 and 3 (GALR1, 2 and 3). In our previous studies, the GAL immunoexpression was compared in colorectal cancer (CRC) tissue and the adjacent parts of the large intestine wall including myenteric and submucosal plexuses. Recently we have also found that expression levels of GALR1 and GALR3 proteins are elevated in CRC tissue as compared with their expression in epithelial cells of unchanged mucosa. Moreover, higher GALR3 immunoreactivity in CRC cells correlated with better prognosis of CRC patients. To understand the distribution of GALRs in enteric plexuses distal and close to CRC invasion, in the present study we decided to evaluate GALRs expression within the myenteric and submucosal plexuses located proximally and distally to the cancer invasion and correlated the GALRs expression levels with the clinico-pathological data of CRC patients. The immunohistochemical and immunofluorescent methods showed only slightly decreased immunoexpression of GALR1 and GALR3 in myenteric plexuses close to cancer but did not reveal any correlation in the immunoexpression of all three GAL receptors in myenteric plexuses and tumour progression. No significant changes were found between the expression levels of GALRs in submucosal plexuses distal and close to the tumour. However, elevated GALR1 expression in submucosal plexuses in vicinity of CRC correlated with poor prognosis, higher tumour grading and shorter overall survival. When myenteric plexuses undergo morphological and functional alterations characteristic for atrophy, GALRs maintain or only slightly decrease their expression status. In contrast, the correlation between high expression of GALR1 in the submucosal plexuses and overall survival of CRC patients suggest that GAL and GALRs can act as a components of local neuro-paracrine pro-proliferative pathways accelerating the invasion and metastasis of cancer cell. The obtained results suggest an important role of GALR1 in submucosal plexuses function during the progression of CRC and imply that GALR1 expression in submucosal plexuses of ENS could be an important predictive factor for CRC progression.
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Affiliation(s)
- Jacek Kiezun
- Department of Human Histology and Embryology, School of Medicine, University of Warmia and Mazury in Olsztyn, Warszawska Street 30, 10-082 Olsztyn, Poland
- Correspondence: ; Tel.: +48-89-524-53-06
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Street 1a, 10-719 Olsztyn, Poland
| | - Bartlomiej Emil Krazinski
- Department of Human Histology and Embryology, School of Medicine, University of Warmia and Mazury in Olsztyn, Warszawska Street 30, 10-082 Olsztyn, Poland
| | - Lukasz Paukszto
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-719 Olsztyn, Poland
| | - Anna Koprowicz-Wielguszewska
- Department of Human Histology and Embryology, School of Medicine, University of Warmia and Mazury in Olsztyn, Warszawska Street 30, 10-082 Olsztyn, Poland
| | - Zbigniew Kmiec
- Department of Histology, Faculty of Medicine, Medical University of Gdansk, Sklodowskiej-Curie Street 3a, 80-211 Gdansk, Poland
| | - Janusz Godlewski
- Department of Human Histology and Embryology, School of Medicine, University of Warmia and Mazury in Olsztyn, Warszawska Street 30, 10-082 Olsztyn, Poland
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5
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Heo Y, Ishimoto N, Jeon YE, Yun JH, Ohki M, Anraku Y, Sasaki M, Kita S, Fukuhara H, Ikuta T, Kawakami K, Inoue A, Maenaka K, Tame JRH, Lee W, Park SY. Structure of the human galanin receptor 2 bound to galanin and Gq reveals the basis of ligand specificity and how binding affects the G-protein interface. PLoS Biol 2022; 20:e3001714. [PMID: 35913979 PMCID: PMC9371267 DOI: 10.1371/journal.pbio.3001714] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 08/11/2022] [Accepted: 06/15/2022] [Indexed: 11/18/2022] Open
Abstract
Galanin is a neuropeptide expressed in the central and peripheral nervous systems, where it regulates various processes including neuroendocrine release, cognition, and nerve regeneration. Three G-protein coupled receptors (GPCRs) for galanin have been discovered, which is the focus of efforts to treat diseases including Alzheimer’s disease, anxiety, and addiction. To understand the basis of the ligand preferences of the receptors and to assist structure-based drug design, we used cryo-electron microscopy (cryo-EM) to solve the molecular structure of GALR2 bound to galanin and a cognate heterotrimeric G-protein, providing a molecular view of the neuropeptide binding site. Mutant proteins were assayed to help reveal the basis of ligand specificity, and structural comparison between the activated GALR2 and inactive hβ2AR was used to relate galanin binding to the movements of transmembrane (TM) helices and the G-protein interface.
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Affiliation(s)
- Yunseok Heo
- Structural Biochemistry & Molecular Biophysics Laboratory, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute (KBSI), Chungbuk, Korea
| | - Naito Ishimoto
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Ye-Eun Jeon
- Structural Biochemistry & Molecular Biophysics Laboratory, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Ji-Hye Yun
- Structural Biochemistry & Molecular Biophysics Laboratory, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
- PCG-Biotech, Ltd., Seoul, Korea
| | - Mio Ohki
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Yuki Anraku
- Faculty of Pharmaceutical Sciences and Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Hokkaido, Japan
| | - Mina Sasaki
- Faculty of Pharmaceutical Sciences and Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Hokkaido, Japan
| | - Shunsuke Kita
- Faculty of Pharmaceutical Sciences and Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Hokkaido, Japan
| | - Hideo Fukuhara
- Faculty of Pharmaceutical Sciences and Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Hokkaido, Japan
| | - Tatsuya Ikuta
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Katsumi Maenaka
- Faculty of Pharmaceutical Sciences and Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Hokkaido, Japan
| | - Jeremy R. H. Tame
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Weontae Lee
- Structural Biochemistry & Molecular Biophysics Laboratory, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
- PCG-Biotech, Ltd., Seoul, Korea
- * E-mail: (WL); (S-YP)
| | - Sam-Yong Park
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
- * E-mail: (WL); (S-YP)
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Wang M, Zhu Z, Kan Y, Yu M, Guo W, Ju M, Wang J, Yi S, Han S, Shang W, Zhang Z, Zhang L, Fang P. Treatment with spexin mitigates diet-induced hepatic steatosis in vivo and in vitro through activation of galanin receptor 2. Mol Cell Endocrinol 2022; 552:111688. [PMID: 35654225 DOI: 10.1016/j.mce.2022.111688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/28/2022] [Accepted: 05/25/2022] [Indexed: 01/12/2023]
Abstract
It was reported that spexin as an adipocyte-secreted protein could regulate obesity and insulin resistance. However, the specific metabolic contribution of spexin to fatty liver remains incompletely understood. Herein, we investigated the effects of spexin on hepatosteatosis and explored the underlying molecular mechanisms. HFD-fed mice were injected with spexin and/or GALR2 antagonist M871, while PA-induced HepG2 cells were treated with spexin in the absence or presence of M871 for 12 h, respectively. Gene expression in liver tissues and hepatocytes was assessed by qRT-PCR and western blotting, respectively. The results showed that body weight, visceral fat content, liver lipid droplet formation, hepatic intracellular triglyceride, and serum triglyceride were reduced in spexin-treated mice. Furthermore, spexin increased the expression of hepatic CPT1A, PPARα, SIRT1, KLF9, PGC-1α and PEPCK in vivo and in vitro. Additionally, spexin treatment improved glucose tolerance and insulin sensitivity in mice fed the HFD. Interestingly, these spexin-mediated beneficial effects were abolished by the GALR2 antagonist M871 in mice fed HFD and PA-induced HepG2 cells, suggesting that spexin mitigated HFD-induced hepatic steatosis by activating the GALR2, thereby increasing CPT1A, PPARα, SIRT1, KLF9, PGC-1α and PEPCK expression. Taken together, these data suggest that spexin ameliorates NAFLD by improving lipolysis and fatty acid oxidation via activation of GALR2 signaling.
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Affiliation(s)
- Mengyuan Wang
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Ziyue Zhu
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Yue Kan
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Mei Yu
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Wancheng Guo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Mengxian Ju
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Junjun Wang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Shuxin Yi
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Shiyu Han
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Wenbin Shang
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China.
| | - Li Zhang
- Hanlin College, Nanjing University of Chinese Medicine, Taizhou, 225300, China.
| | - Penghua Fang
- Key Laboratory for Metabolic Diseases in Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China; Hanlin College, Nanjing University of Chinese Medicine, Taizhou, 225300, China.
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7
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Kiezun J, Godlewski J, Krazinski BE, Kozielec Z, Kmiec Z. Galanin Receptors (GalR1, GalR2, and GalR3) Expression in Colorectal Cancer Tissue and Correlations to the Overall Survival and Poor Prognosis of CRC Patients. Int J Mol Sci 2022; 23:ijms23073735. [PMID: 35409094 PMCID: PMC8998502 DOI: 10.3390/ijms23073735] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/23/2022] [Accepted: 03/25/2022] [Indexed: 01/11/2023] Open
Abstract
Colorectal cancer (CRC) is the second most common cause of cancer in women and the third in men. The postoperative pathomorphological evaluation of patients with CRC is extremely important for future therapeutic decisions. Although our previous studies demonstrated high galanin (GAL) presence within tumor tissue and an elevated concentration of GAL in the serum of CRC patients, to date, there is a lack of data regarding GAL receptor (GalR) protein expression in CRC cells. Therefore, the aim of this study was to evaluate the presence of all three types of GalRs (GalR1, GalR2 and GalR3) within epithelial cells of the human colon and CRC tissue with the use of the immunohistochemical method and to correlate the results with the clinical-pathological data. We found stronger immunoreactivity of GalR1 and GalR3 in CRC cells compared to epithelial cells of the unchanged mucosa of the large intestine. No differences in the GalR2 protein immunoreactivity between the studied tissues were noted. We also found that the increased immunoexpression of the GalR3 in CRC tissue correlated with the better prognosis and longer survival (p < 0.0079) of CRC patients (n = 55). The obtained results suggest that GalR3 may play the role of a prognostic factor for CRC patients. Based on data from the TCGA-COAD project deposited in the GDC Data Portal, we also found that GalR mRNA in cancer samples and the adjacent normal tissue did not correlate with immunoexpression of the GalR proteins in CRC cells and epithelial cells of the unchanged mucosa.
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MESH Headings
- Colorectal Neoplasms/genetics
- Female
- Humans
- Male
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/metabolism
- Receptors, Galanin/genetics
- Receptors, Galanin/metabolism
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Affiliation(s)
- Jacek Kiezun
- Department of Human Histology and Embryology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland; (J.G.); (B.E.K.)
- Correspondence: ; Tel.: +48-89-524-53-06
| | - Janusz Godlewski
- Department of Human Histology and Embryology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland; (J.G.); (B.E.K.)
| | - Bartlomiej E. Krazinski
- Department of Human Histology and Embryology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, 10-082 Olsztyn, Poland; (J.G.); (B.E.K.)
| | - Zygmunt Kozielec
- Department of Pathomorphology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, 10-561 Olsztyn, Poland;
| | - Zbigniew Kmiec
- Department of Histology, Faculty of Medicine, Medical University of Gdansk, 80-211 Gdansk, Poland;
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Yu M, Han S, Wang M, Han L, Huang Y, Bo P, Fang P, Zhang Z. Baicalin protects against insulin resistance and metabolic dysfunction through activation of GALR2/GLUT4 signaling. Phytomedicine 2022; 95:153869. [PMID: 34923235 DOI: 10.1016/j.phymed.2021.153869] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 11/14/2021] [Accepted: 11/27/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Type 2 diabetes mellitus is a complex metabolic disorder associated with obesity, glucose intolerance and insulin resistance. Activation of GALR2 has been proposed as a therapeutic target for the treatment of insulin resistance. The previous studies showed that baicalin could mitigate insulin resistance, but the detailed mechanism of baicalin on insulin resistance has not been fully explored yet. PURPOSE In the present study, we evaluated whether baicalin mitigated insulin resistance via activation of GALR2 signaling pathway. STUDY DESIGN/METHODS Baicalin (25 mg/kg/d and 50 mg/kg/d) and/or GALR2 antagonist M871 (10 mg/kg/d) were injected individually or in combinations into obese mice once a day for three weeks, and normal and GALR2 knockdown myotubes were treated with baicalin (100 μM and 400 μM) or metformin (4 mM) in the absence or presence of M871 (800 nM) for 12 h, respectively. The molecular mechanism was explored in skeletal muscle and L6 myotubes. RESULTS The present findings showed that baicalin mitigated hyperglycemia and insulin resistance and elevated the levels of PGC-1α, GLUT4, p-p38MAPK, p-AKT and p-AS160 in skeletal muscle of obese mice. Strikingly, the baicalin-induced beneficial effects were abolished by GALR2 antagonist M871 in obese mice. In vitro, baicalin dramatically augmented glucose consumption and the activity of PGC1α-GLUT4 axis in myotubes through activation of p38MAPK and AKT pathways. Moreover, baicalin-induced elevations in glucose consumption related genes were abolished by GALR2 antagonist M871 or silencing of GALR2 in myotubes. CONCLUSIONS The present study for the first time demonstrated that baicalin protected against insulin resistance and metabolic dysfunction mainly through activation of GALR2-GLUT4 signal pathway. Our findings identified that activation of GALR2-GLUT4 signal pathway by baicalin could be a new therapeutic approach to treat insulin resistance and T2DM in clinic.
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Affiliation(s)
- Mei Yu
- Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Shiyu Han
- Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Mengyuan Wang
- Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Long Han
- Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Yujie Huang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China
| | - Penghua Fang
- Key Laboratory for Metabolic Diseases in Chinese Medicine, First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China; Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou 225300, China.
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China.
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9
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Kuipers A, Balaskó M, Pétervári E, Koller A, Brunner SM, Moll GN, Kofler B. Intranasal Delivery of a Methyllanthionine-Stabilized Galanin Receptor-2-Selective Agonist Reduces Acute Food Intake. Neurotherapeutics 2021; 18:2737-2752. [PMID: 34859381 PMCID: PMC8804135 DOI: 10.1007/s13311-021-01155-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2021] [Indexed: 11/27/2022] Open
Abstract
The regulatory (neuro)peptide galanin is widely distributed in the central and peripheral nervous systems, where it mediates its effects via three G protein-coupled receptors (GAL1-3R). Galanin has a vast diversity of biological functions, including modulation of feeding behavior. However, the clinical application of natural galanin is not practicable due to its rapid in vivo breakdown by peptidases and lack of receptor subtype specificity. Much effort has been put into the development of receptor-selective agonists and antagonists, and while receptor selectivity has been attained to some degree, most ligands show overlapping affinity. Therefore, we aimed to develop a novel ligand with specificity to a single galanin receptor subtype and increased stability. To achieve this, a lanthionine amino acid was enzymatically introduced into a galanin-related peptide. The residue's subsequent cyclization created a conformational constraint which increased the peptide's receptor specificity and proteolytic resistance. Further exchange of certain other amino acids resulted in a novel methyllanthionine-stabilized galanin receptor agonist, a G1pE-T3N-S6A-G12A-methyllanthionine[13-16]-galanin-(1-17) variant, termed M89b. M89b has exclusive specificity for GAL2R and a prolonged half-life in serum. Intranasal application of M89b to unfasted rats significantly reduced acute 24 h food intake inducing a drop in body weight. Combined administration of M89b and M871, a selective GAL2R antagonist, abolished the anorexigenic effect of M89b, indicating that the effect of M89b on food intake is indeed mediated by GAL2R. This is the first demonstration of in vivo activity of an intranasally administered lanthipeptide. Consequently, M89b is a promising candidate for clinical application as a galanin-related peptide-based therapeutic.
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Affiliation(s)
- Anneke Kuipers
- Lanthio Health B.V., Rozenburglaan 13B, 9727 DL, Groningen, Netherlands
| | - Márta Balaskó
- Institute for Translational Medicine, Medical School, University of Pécs, 12 Szigeti út, H-7624, Pécs, Hungary
| | - Erika Pétervári
- Institute for Translational Medicine, Medical School, University of Pécs, 12 Szigeti út, H-7624, Pécs, Hungary
| | - Andreas Koller
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstr. 48, 5020, Salzburg, Austria
- Research Program for Experimental Ophthalmology, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Susanne M Brunner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstr. 48, 5020, Salzburg, Austria
- Research Program for Experimental Ophthalmology, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Gert N Moll
- Lanthio Health B.V., Rozenburglaan 13B, 9727 DL, Groningen, Netherlands
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, Netherlands
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstr. 48, 5020, Salzburg, Austria.
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10
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Borroto-Escuela DO, Pita-Rodriguez M, Fores-Pons R, Barbancho MA, Fuxe K, Narváez M. Galanin and neuropeptide Y interactions elicit antidepressant activity linked to neuronal precursor cells of the dentate gyrus in the ventral hippocampus. J Cell Physiol 2021; 236:3565-3578. [PMID: 33044017 DOI: 10.1002/jcp.30092] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 01/18/2023]
Abstract
A need for new antidepressants is necessary since traditional antidepressants have several flaws. Neuropeptide Y(NPY) Y1 receptor (NPYY1R) and galanin (GAL) receptor 2 (GALR2) interact in several regions of the limbic system, including the hippocampus. The current study assesses the antidepressant effects induced by GALR2 and NPYY1R coactivation, together with the evaluation of cell proliferation through 5-Bromo-2'-deoxyuridine expression within the dentate gyrus of the ventral hippocampus (vDG). We employed in situ proximity ligation assay to manifest GALR2/NPYY1R heteroreceptor complexes. Additionally, the expression pattern of GALR2 and the activation of the extracellular-regulated kinases (ERK) pathway after GALR2 and NPYY1R costimulation in cell cultures were examined. GALR2 and NPYY1R coactivation resulted in sustained antidepressant behaviors in the FST after 24 h, linked to increased cell proliferation in the vDG. Moreover, an increased density of GALR2/NPYY1R heteroreceptor complexes was observed in vDG, on doublecortin-expressing neuroblasts. Recruitment of the GALR2 expression to the plasma membrane was observed upon the coactivation of GALR2 and NPYY1R in cell cultures, presumably associated to the enhanced effects on the activation of ERK pathway. GALR2 may promote the GALR2/NPYY1R heteroreceptor complexes formation in the ventral hippocampus. It may induce a transformation of cell proliferation toward a neuronal lineage by enhancement of ERK pathway. Thus, it may give the mechanism for the antidepressant behavior observed. These results may provide the basis for the development of heterobivalent agonist pharmacophores, targeting GALR2/NPYY1R heteromers, especially in the neuronal precursor cells of the dentate gyrus in the ventral hippocampus for the novel treatment of depression.
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Affiliation(s)
- Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Department of Biomolecular Science, Section of Physiology, University of Urbino, Urbino, Italy
- Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Mariana Pita-Rodriguez
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Departamento de Neurogenética, Instituto de Neurología y Neurocirugía, La Habana, Cuba
| | - Ramón Fores-Pons
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Miguel A Barbancho
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Manuel Narváez
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
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11
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Dong Y, Li CY, Zhang XM, Liu YN, Yang S, Li MN, Xu SL. The activation of galanin receptor 2 plays an antinociceptive effect in nucleus accumbens of rats with neuropathic pain. J Physiol Sci 2021; 71:6. [PMID: 33546583 PMCID: PMC10717428 DOI: 10.1186/s12576-021-00790-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 01/07/2021] [Indexed: 11/10/2022]
Abstract
Our previous research has shown that galanin plays an antinociceptive effect via binding to galanin receptors (GalRs) in nucleus accumbens (NAc). This study focused on the involvement of GalR2 in galanin-induced antinociceptive effect in NAc of neuropathic pain rats. The chronic constriction injury of sciatic nerve (CCI) was used to mimic neuropathic pain model. The hind paw withdrawal latency (HWL) to thermal stimulation and hind paw withdrawal threshold (HWT) to mechanical stimulation were measured as the indicators of pain threshold. The results showed that 14 and 28 days after CCI, the expression of GalR2 was up-regulated in bilateral NAc of rats, and intra-NAc injection of GalR2 antagonist M871 reversed galanin-induced increases in HWL and HWT of CCI rats. Furthermore, intra-NAc injection of GalR2 agonist M1145 induced increases in HWL and HWT at day 14 and day 28 after CCI, which could also be reversed by M871. Finally, we found that M1145-induced antinociceptive effect in NAc of CCI rats was stronger than that in intact rats. These results imply that the GalR2 is activated in the NAc from day 14 to day 28 after CCI and GalR2 is involved in the galanin-induced antinociceptive effect in NAc of CCI rats.
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Affiliation(s)
- Yan Dong
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Chong-Yang Li
- Department of Oncology, Affiliated Hospital, Yunnan University, Kunming, Yunnan, China
| | - Xiao-Min Zhang
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Ya-Nan Liu
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Shuang Yang
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Meng-Nan Li
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Shi-Lian Xu
- Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China.
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12
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Wong MKH, He M, Sze KH, Huang T, Ko WKW, Bian ZX, Wong AOL. Mouse Spexin: (I) NMR Solution Structure, Docking Models for Receptor Binding, and Histological Expression at Tissue Level. Front Endocrinol (Lausanne) 2021; 12:681646. [PMID: 34276561 PMCID: PMC8285161 DOI: 10.3389/fendo.2021.681646] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/27/2021] [Indexed: 01/10/2023] Open
Abstract
Spexin (SPX), a highly conserved neuropeptide, is known to have diverse functions and has been implicated/associated with pathological conditions, including obesity, diabetes, anorexia nervosa, and anxiety/mood disorders. Although most of the studies on SPX involved the mouse model, the solution structure of mouse SPX, structural aspects for SPX binding with its receptors GalR2/3, and its cellular expression/distribution in mouse tissues are largely unknown. Using CD and NMR spectroscopies, the solution structure of mouse SPX was shown to be in the form of a helical peptide with a random coil from Asn1 to Pro4 in the N-terminal followed by an α-helix from Gln5 to Gln14 in the C-terminus. The molecular surface of mouse SPX is largely hydrophobic with Lys11 as the only charged residue in the α-helix. Based on the NMR structure obtained, docking models of SPX binding with mouse GalR2 and GalR3 were constructed by homology modeling and MD simulation. The models deduced reveal that the amino acids in SPX, especially Asn1, Leu8, and Leu10, could interact with specific residues in ECL1&2 and TMD2&7 of GalR2 and GalR3 by H-bonding/hydrophobic interactions, which provides the structural evidence to support the idea that the two receptors can act as the cognate receptors for SPX. For tissue distribution of SPX, RT-PCR based on 28 tissues/organs harvested from the mouse demonstrated that SPX was ubiquitously expressed at the tissue level with notable signals detected in the brain, GI tract, liver, gonad, and adrenal gland. Using immunohistochemical staining, protein signals of SPX could be located in the liver, pancreas, white adipose tissue, muscle, stomach, kidney, spleen, gonad, adrenal, and hypothalamo-pituitary axis in a cell type-specific manner. Our results, as a whole, not only can provide the structural information for ligand/receptor interaction for SPX but also establish the anatomical basis for our on-going studies to examine the physiological functions of SPX in the mouse model.
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Affiliation(s)
- Matthew K. H. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Mulan He
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kong Hung Sze
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong, Hong Kong
| | - Tao Huang
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Wendy K. W. Ko
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Zhao-Xiang Bian
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Anderson O. L. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
- *Correspondence: Anderson O. L. Wong,
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Wang L, Tran A, Lee J, Belsham DD. Palmitate differentially regulates Spexin, and its receptors Galr2 and Galr3, in GnRH neurons through mechanisms involving PKC, MAPKs, and TLR4. Mol Cell Endocrinol 2020; 518:110991. [PMID: 32841709 DOI: 10.1016/j.mce.2020.110991] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/03/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023]
Abstract
The function of the gonadotropin-releasing hormone (GnRH) neuron is critical to maintain reproductive function and a significant decrease in GnRH can lead to disorders affecting fertility, including hypogonadotropic hypogonadism. Spexin (SPX) is a novel hypothalamic neuropeptide that exerts inhibitory effects on reproduction and feeding by acting through galanin receptor 2 (GALR2) and galanin receptor 3 (GALR3). Fatty acids can act as nutritional signals that regulate the hypothalamic-pituitary-gonadal (HPG) axis, and elevated levels of circulating saturated fatty acids associated with high fat diet (HFD)-feeding have been shown to induce neuroinflammation, endoplasmic reticulum stress and hormonal resistance in the hypothalamus, as well as alter neuropeptide expression. We previously demonstrated that palmitate, the most common saturated fatty acid in a HFD, elevates the expression of Spx, Galr2 and Galr3 mRNA in a model of appetite-regulating neuropeptide Y hypothalamic neurons. Here, we found that Spx, Galr2 and Galr3 mRNA were also significantly induced by palmitate in a model of reproductive GnRH neurons, mHypoA-GnRH/GFP. As a follow-up to our previous report, we examined the molecular pathways by which Spx and galanin receptor mRNA was regulated in this cell line. Furthermore, we performed inhibitor studies, which revealed that the effect of palmitate on Spx and Galr3 mRNA involved activation of the innate immune receptor TLR4, and we detected differential regulation of the three genes by the protein kinases PKC, JNK, ERK, and p38. However, the intracellular metabolism of palmitate to ceramide did not appear to be involved in the palmitate-mediated gene regulation. Overall, this suggests that SPX may play a role in reproduction at the level of the hypothalamus and the pathways by which Spx, Galr2 and Galr3 are altered by fatty acids could provide insight into the mechanisms underlying reproductive dysfunction in obesity.
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Affiliation(s)
- Lu Wang
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Andy Tran
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Juliette Lee
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Denise D Belsham
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada; Medicine, Faculty of Medicine, University of Toronto, Ontario, Canada; Obstetrics and Gynecology, Faculty of Medicine, University of Toronto, Ontario, Canada.
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15
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Lee YN, Reyes-Alcaraz A, Yun S, Lee CS, Hwang JI, Seong JY. Exploring the molecular structures that confer ligand selectivity for galanin type II and III receptors. PLoS One 2020; 15:e0230872. [PMID: 32231393 PMCID: PMC7108740 DOI: 10.1371/journal.pone.0230872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/10/2020] [Indexed: 01/09/2023] Open
Abstract
Galanin receptors (GALRs) belong to the superfamily of G-protein coupled receptors. The three GALR subtypes (GALR1, GALR2, and GALR3) are activated by their endogenous ligands: spexin (SPX) and galanin (GAL). The synthetic SPX-based GALR2-specific agonist, SG2A, plays a dual role in the regulation of appetite and depression-like behaviors. Little is known, however, about the molecular interaction between GALR2 and SG2A. Using site-directed mutagenesis and domain swapping between GALR2 and GALR3, we identified residues in GALR2 that promote interaction with SG2A and residues in GALR3 that inhibit interaction with SG2A. In particular, Phe103, Phe106, and His110 in the transmembrane helix 3 (TM3) domain; Val193, Phe194, and Ser195 in the TM5 domain; and Leu273 in the extracellular loop 3 (ECL3) domain of GALR2 provide favorable interactions with the Asn5, Ala7, Phe11, and Pro13 residues of SG2A. Our results explain how SG2A achieves selective interaction with GALR2 and inhibits interaction with GALR3. The results described here can be used broadly for in silico virtual screening of small molecules for the development of GALR subtype-specific agonists and/or antagonists.
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MESH Headings
- Amino Acid Sequence
- Animals
- HEK293 Cells
- Humans
- Ligands
- Mice
- Mutation
- Protein Domains
- Receptor, Galanin, Type 2/chemistry
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/chemistry
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Substrate Specificity
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Affiliation(s)
- Yoo-Na Lee
- The GPCR laboratory, Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
| | - Arfaxad Reyes-Alcaraz
- The GPCR laboratory, Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
- College of Pharmacy, University of Houston, Houston, Texas, United States of America
| | - Seongsik Yun
- The GPCR laboratory, Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
| | - Cheol Soon Lee
- Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jong-Ik Hwang
- The GPCR laboratory, Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae Young Seong
- The GPCR laboratory, Graduate School of Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea
- * E-mail:
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Petrescu AD, Grant S, Williams E, Frampton G, Parks N, Blaney H, Davies M, John R, Reinhart EH, McMillin M, DeMorrow S. Coordinated Targeting of Galanin Receptors on Cholangiocytes and Hepatic Stellate Cells Ameliorates Liver Fibrosis in Multidrug Resistance Protein 2 Knockout Mice. Am J Pathol 2020; 190:586-601. [PMID: 31953035 PMCID: PMC7074378 DOI: 10.1016/j.ajpath.2019.10.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/20/2019] [Accepted: 10/22/2019] [Indexed: 01/12/2023]
Abstract
Galanin (Gal) is a peptide with a role in neuroendocrine regulation of the liver. In this study, we assessed the role of Gal and its receptors, Gal receptor 1 (GalR1) and Gal receptor 2 (GalR2), in cholangiocyte proliferation and liver fibrosis in multidrug resistance protein 2 knockout (Mdr2KO) mice as a model of chronic hepatic cholestasis. The distribution of Gal, GalR1, and GalR2 in specific liver cell types was assessed by laser-capture microdissection and confocal microscopy. Galanin immunoreactivity was detected in cholangiocytes, hepatic stellate cells (HSCs), and hepatocytes. Cholangiocytes expressed GalR1, whereas HSCs and hepatocytes expressed GalR2. Strategies were used to either stimulate or block GalR1 and GalR2 in FVB/N (wild-type) and Mdr2KO mice and measure biliary hyperplasia and hepatic fibrosis by quantitative PCR and immunostaining of specific markers. Galanin treatment increased cholangiocyte proliferation and fibrogenesis in both FVB/N and Mdr2KO mice. Suppression of GalR1, GalR2, or both receptors in Mdr2KO mice resulted in reduced bile duct mass and hepatic fibrosis. In vitro knockdown of GalR1 in cholangiocytes reduced α-smooth muscle actin expression in LX-2 cells treated with cholangiocyte-conditioned media. A GalR2 antagonist inhibited HSC activation when Gal was administered directly to LX-2 cells, but not via cholangiocyte-conditioned media. These data demonstrate that Gal contributes not only to cholangiocyte proliferation but also to liver fibrogenesis via the coordinate activation of GalR1 in cholangiocytes and GalR2 in HSCs.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/genetics
- Animals
- Bile Ducts/metabolism
- Cell Proliferation
- Cholestasis/metabolism
- Cholestasis/pathology
- Disease Models, Animal
- Epithelial Cells/metabolism
- Female
- Galanin/genetics
- Galanin/metabolism
- Hepatic Stellate Cells/metabolism
- Hepatic Stellate Cells/pathology
- Liver/metabolism
- Liver/pathology
- Liver Cirrhosis/metabolism
- Liver Cirrhosis/pathology
- Mice
- Mice, Knockout
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- ATP-Binding Cassette Sub-Family B Member 4
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Affiliation(s)
- Anca D Petrescu
- Research Division, Central Texas Veterans Health Care System, Temple, Texas; Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas
| | - Stephanie Grant
- Research Division, Central Texas Veterans Health Care System, Temple, Texas; Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas
| | - Elaina Williams
- Research Division, Central Texas Veterans Health Care System, Temple, Texas; Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas
| | - Gabriel Frampton
- Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, Texas
| | | | - Hanna Blaney
- Department of Internal Medicine, Baylor Scott & White Health, Temple, Texas
| | - Marcus Davies
- Department of Internal Medicine, Baylor Scott & White Health, Temple, Texas
| | - Rebekah John
- Department of Internal Medicine, Baylor Scott & White Health, Temple, Texas
| | - Evan H Reinhart
- Department of Internal Medicine, Baylor Scott & White Health, Temple, Texas
| | - Matthew McMillin
- Research Division, Central Texas Veterans Health Care System, Temple, Texas; Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, Texas
| | - Sharon DeMorrow
- Research Division, Central Texas Veterans Health Care System, Temple, Texas; Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas; Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, Texas.
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17
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Abstract
Expression of neuropeptides and their corresponding receptors has been demonstrated in different cancer types, where they can play a role in tumor cell growth, invasion, and migration. Human galanin (GAL) is a 30-amino-acid regulatory neuropeptide which acts through three G protein-coupled receptors, GAL1-R, GAL2-R, and GAL3-R that differ in their signal transduction pathways. GAL and galanin receptors (GALRs) are expressed by different tumors, and direct involvement of GAL in tumorigenesis has been shown. Despite its strong expression in the central nervous system (CNS), the role of GAL in CNS tumors has not been extensively studied. To date, GAL peptide expression, GAL receptor binding and mRNA expression have been reported in glioma, meningioma, and pituitary adenoma. However, data on the cellular distribution of GALRs are sparse. The aim of the present study was to examine the expression of GAL and GALRs in different brain tumors by immunohistochemistry. Anterior pituitary gland (n = 7), pituitary adenoma (n = 9) and glioma of different WHO grades I-IV (n = 55) were analyzed for the expression of GAL and the three GALRs with antibodies recently extensively validated for specificity. While high focal GAL immunoreactivity was detected in up to 40% of cells in the anterior pituitary gland samples, only one pituitary adenoma showed focal GAL expression, at a low level. In the anterior pituitary, GAL1-R and GAL3-R protein expression was observed in up to 15% of cells, whereas receptor expression was not detected in pituitary adenoma. In glioma, diffuse and focal GAL staining was noticed in the majority of cases. GAL1-R was observed in eight out of nine glioma subtypes. GAL2-R immunoreactivity was not detected in glioma and pituitary adenoma, while GAL3-R expression was significantly associated to high-grade glioma (WHO grade IV). Most interestingly, expression of GAL and GALRs was observed in tumor-infiltrating immune cells, including neutrophils and glioma-associated macrophages/microglia. The presence of GALRs on tumor-associated immune cells, especially macrophages, indicates that GAL signaling contributes to homeostasis of the tumor microenvironment. Thus, our data indicate that GAL signaling in tumor-supportive myeloid cells could be a novel therapeutic target.
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MESH Headings
- Adenoma/genetics
- Adenoma/metabolism
- Adenoma/pathology
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Brain Neoplasms/genetics
- Brain Neoplasms/metabolism
- Brain Neoplasms/pathology
- Child
- Child, Preschool
- Galanin/genetics
- Galanin/metabolism
- Gene Expression Regulation, Neoplastic
- Glioma/genetics
- Glioma/metabolism
- Glioma/pathology
- Humans
- Middle Aged
- Pituitary Neoplasms/genetics
- Pituitary Neoplasms/metabolism
- Pituitary Neoplasms/pathology
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Receptors, Galanin/genetics
- Receptors, Galanin/metabolism
- Young Adult
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Affiliation(s)
- Sarah Falkenstetter
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Julia Leitner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Susanne M. Brunner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Tim N. Rieder
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
- *Correspondence: Barbara Kofler
| | - Serge Weis
- Division of Neuropathology, Department of Pathology and Neuropathology, Neuromed, School of Medicine Campus, Kepler University Hospital, Johannes Kepler University, Linz, Austria
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18
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Chen K, Yan JQ, Sun B, Luo X, Wang N, Lyu B. [Nutritional status alters the mRNA expressions of galanin and its receptors in taste buds of rats]. Sheng Li Xue Bao 2019; 71:294-300. [PMID: 31008489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The nutritional and metabolic status alters the peripheral taste perception and food intake by participating in the modulation of taste information integration. The taste receptors and neuropeptides in the taste buds are the important targets of this modulation process. To explore the effects of nutritional status on the expressions of galanin and its receptors in the taste buds, we compared the mRNA levels of galanin and its specific receptor GalR2 in the taste buds among the high-fat diet induced obese rats (HF), chronically restricted diet rats (CR) and control rats. The high-fat diet, half of chow diet, and normal chow diet were given to HF, CR and control groups for 6 weeks, respectively. The body weight and some metabolic indexes, including blood glucose, triglyceride and cholesterol levels were detected. The mRNA expressions of galanin and its receptors in taste buds were determined using real-time PCR. Results showed that compared with control rats, the body weights, levels of blood glucose and triglyceride were significantly elevated in HF rats; while the mRNA expressions of galanin and GalR2 were dramatically decreased. However, galanin mRNA expression in CR rats was increased to 2.3 times of that in control group. Considering the results obtained from our previous studies, we conclude that the behavioral changes in tasting choice of HF rats may be related to the expressions of galanin and GalR2 in the taste buds. The changes of galanin and GalR2 in taste buds are involved in the peripheral mechanism of nutritional status regulating taste perception and feeding behavior in rats.
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Affiliation(s)
- Ke Chen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Jian-Qun Yan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| | - Bo Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Xiao Luo
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Nan Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Bo Lyu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
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19
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Chen SH, Lue JH, Hsiao YJ, Lai SM, Wang HY, Lin CT, Chen YC, Tsai YJ. Elevated galanin receptor type 2 primarily contributes to mechanical hypersensitivity after median nerve injury. PLoS One 2018; 13:e0199512. [PMID: 29928003 PMCID: PMC6013116 DOI: 10.1371/journal.pone.0199512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 06/09/2018] [Indexed: 12/22/2022] Open
Abstract
In this study, we investigated temporal changes in galanin receptor type 2 (GalR2) expression in NF200-, galanin-, neuropeptide Y (NPY)-, and neuronal nitric oxide synthase (nNOS)-like immunoreactive (LI) dorsal root ganglion (DRG) neurons after median nerve chronic constriction injury (CCI), and the effects of GalR2 on c-Fos expression in the cuneate nucleus (CN). Double immunofluorescence labeling methods were used to appraise changes in GalR2 expression in NF200-LI, galanin-LI, NPY-LI, and nNOS-LI DRG neurons after CCI. The von Frey assay was used to assess the efficiency of intraplantar administration of saline, M871 (a GalR2 antagonist), or AR-M1896 (a GalR2 agonist) on neuropathic signs of rats with CCI. The effects of alterations in c-Fos expression were assessed in all treatments. The percentage of GalR2-LI neurons in lesioned DRGs increased and peaked at 1 week after CCI. We further detected that percentages of GalR2-LI neurons labeled for NF200, galanin, NPY, and nNOS significantly increased following CCI. Furthermore, M871 remarkably attenuated tactile allodynia, but the sensation was slightly aggravated by AR-M1896 after CCI. Consequentially, after electrical stimulation of the CCI-treated median nerve, the number of c-Fos-LI neurons in the cuneate nucleus (CN) was significantly reduced in the M871 group, whereas it increased in the AR-M1896 group. These results suggest that activation of GalR2, probably through NPY or nitric oxide, induces c-Fos expression in the CN and transmits mechanical allodynia sensations to the thalamus.
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Affiliation(s)
- Seu-Hwa Chen
- Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - June-Horng Lue
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yung-Jung Hsiao
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shu-Mei Lai
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsin-Ying Wang
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chi-Te Lin
- Department of Nursing, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Ya-Chin Chen
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Ju Tsai
- Graduate Institute of Biomedical and Pharmaceutical Science, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
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20
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Fang P, Zhang L, Yu M, Sheng Z, Shi M, Zhu Y, Zhang Z, Bo P. Activiated galanin receptor 2 attenuates insulin resistance in skeletal muscle of obese mice. Peptides 2018; 99:92-98. [PMID: 29183756 DOI: 10.1016/j.peptides.2017.11.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 11/24/2017] [Accepted: 11/24/2017] [Indexed: 01/28/2023]
Abstract
The results of our and other's studies showed that activation of galanin receptor 1 could mitigate insulin resistance via promoting glucose transporter 4 (GLUT4) expression and translocation in the skeletal muscle of rats. But no literature are available regarding the effect of galanin receptor 2 (GALR2) on insulin resistance in skeletal muscle of type 2 diabetes. Herein, in this study we intended to survey the effect of GALR2 and its signal mechanisms in the mice with high fat diet-induced obese. The mice were intraperitoneally injected with vehicle, GALR2 agonist M1145 and antagonist M871 respectively once a day for continuous 21 days. The skeletal muscles were processed for determination of glucose uptake, and GLUT4 mRNA and protein expression levels. The PGC-1α, AKT, p38MAPK, AS160, pAKT, pP38MAPK and pAS160 expression levels were quantitatively assessed too. We found that pharmacological activation of GALR2 enhanced energy expenditure, and increased GLUT4 expression and translocation in skeletal muscle of mice during high-fat diet regimens. Activation of GALR2 alleviated insulin resistance through P38MAPK/PGC-1α/GLUT4 and AKT/AS160/GLUT4 pathway in the skeletal muscle of mice. Overall, these results identify that GALR2 is a regulator of insulin resistance and activation of GALR2 represents a promising strategy against obesity-induced insulin resistance.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Nanjing University of Chinese Medicine Hanlin College, Taizhou, Jiangsu, 225300, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Lei Zhang
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Mei Yu
- Department of Physiology, Nanjing University of Chinese Medicine Hanlin College, Taizhou, Jiangsu, 225300, China
| | - Zhongqi Sheng
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Mingyi Shi
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Yan Zhu
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China.
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China.
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21
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Kramáriková I, Šípková J, Šída P, Hynie S, Klenerová V. The Effect of Stress on the Galaninergic System in the Rat Adenohypophysis: mRNA Expression and Immunohistochemistry of Galanin Receptors. Folia Biol (Praha) 2017; 63:197-201. [PMID: 29687773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The neuropeptide galanin is a widely distributed neurotransmitter/neuromodulator that regulates a variety of physiological processes and also participates in the regulation of stress responses. The effect of stress is dependent on the activity of the hypothalamic-adenohypophyseal-adrenal axis. Although the adenohypophysis is a crucial part of this axis, galanin peptides and their receptors have not yet been identified in this part of the pituitary after activation of the stress response. Since there are many controversies about the occurrence of individual galanin receptor subtypes in the adenohypophysis under basal conditions, we decided to verify their presence immunohistochemically, and we clearly demonstrated that the adenohypophysis expresses neuropeptides galanin, galanin-like peptide, and subtypes of galanin receptors GalR1, GalR2 and GalR3. The specificity of the reactions was confirmed by Western blots for galanin receptors. Using real-time qPCR we also demonstrated the presence of three GalR subtypes, with the highest expression of GalR2. In addition, we tested the effect of stress. We found that acute stress did not induce any changes in the GalR2 expression, but increased expression of GalR1 and decreased that of GalR3. We confirmed the involvement of the galanin system in the stress regulation in the adenohypophysis.
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MESH Headings
- Animals
- Blotting, Western
- Galanin/metabolism
- Immunohistochemistry
- Pituitary Gland, Anterior/metabolism
- RNA, Messenger/metabolism
- Rats
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/metabolism
- Receptors, Galanin/metabolism
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Affiliation(s)
- I Kramáriková
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - J Šípková
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - P Šída
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - S Hynie
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - V Klenerová
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic
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22
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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23
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Webling K, Groves-Chapman JL, Runesson J, Saar I, Lang A, Sillard R, Jakovenko E, Kofler B, Holmes PV, Langel Ü. Pharmacological stimulation of GAL1R but not GAL2R attenuates kainic acid-induced neuronal cell death in the rat hippocampus. Neuropeptides 2016; 58:83-92. [PMID: 26764217 DOI: 10.1016/j.npep.2015.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/23/2015] [Accepted: 12/07/2015] [Indexed: 02/08/2023]
Abstract
The neuropeptide galanin is widely distributed in the central and peripheral nervous systems and part of a bigger family of bioactive peptides. Galanin exerts its biological activity through three G-protein coupled receptor subtypes, GAL1-3R. Throughout the last 20years, data has accumulated that galanin can have a neuroprotective effect presumably mediated through the activation of GAL1R and GAL2R. In order to test the pharmaceutical potential of galanin receptor subtype selective ligands to inhibit excitotoxic cell death, the GAL1R selective ligand M617 and the GAL2R selective ligand M1145 were compared to the novel GAL1/2R ligand M1154, in their ability to reduce the excitotoxic effects of intracerebroventricular injected kainate acid in rats. The peptide ligands were evaluated in vitro for their binding preference in a competitive (125)I-galanin receptor subtype binding assay, and G-protein signaling was evaluated using both classical signaling and a label-free real-time technique. Even though there was no significant difference in the time course or severity of the kainic acid induced epileptic behavior in vivo, administration of either M617 or M1154 before kainic acid administration significantly attenuated the neuronal cell death in the hippocampus. Our results indicate the potential therapeutic value of agonists selective for GAL1R in the prevention of neuronal cell death.
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MESH Headings
- Animals
- Bradykinin/analogs & derivatives
- Bradykinin/pharmacology
- Cell Death/drug effects
- Cell Line, Tumor
- Cyclic AMP/metabolism
- Galanin/analogs & derivatives
- Galanin/pharmacology
- Hippocampus/drug effects
- Hippocampus/pathology
- Humans
- Kainic Acid/toxicity
- Ligands
- Male
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Peptide Fragments/pharmacology
- Protein Binding
- Rats
- Rats, Sprague-Dawley
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/metabolism
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Affiliation(s)
- Kristin Webling
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691, Stockholm, Sweden.
| | - Jessica L Groves-Chapman
- Neuroscience Program, Biomedical and Health Science Institute, Department of Psychology, The University of Georgia, Athens, GA, USA
| | - Johan Runesson
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691, Stockholm, Sweden
| | - Indrek Saar
- Institute of technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia
| | - 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, 5020, Salzburg, Austria
| | - Rannar Sillard
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691, Stockholm, Sweden
| | - Erik Jakovenko
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691, Stockholm, Sweden
| | - 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, 5020, Salzburg, Austria
| | - Philip V Holmes
- Neuroscience Program, Biomedical and Health Science Institute, Department of Psychology, The University of Georgia, Athens, GA, USA
| | - 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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24
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Benjamin ER, Haftl SL, Xanthos DN, Crumley G, Hachicha M, Valenzano KJ. A Miniaturized Column Chromatography Method for Measuring Receptor-Mediated Inositol Phosphate Accumulation. ACTA ACUST UNITED AC 2016; 9:343-53. [PMID: 15191651 DOI: 10.1177/1087057103262841] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Inositol phosphates (IPs), such as 1,4,5-inositol-trisphosphate (IP3), comprise a ubiquitous intracellular signaling cascade initiated in response to G protein-coupled receptor-mediated activation of phospholipase C. Classical methods for measuring intracellular accumulation of these molecules include time-consuming high-performance liquid chromatography (HPLC) separation or large-volume, gravity-fed anion-exchange column chromatography. More recent approaches, such as radio-receptor and AlphaScreen™ assays, offer higher throughput. However, these techniques rely on measurement of IP3itself, rather than its accumulation with other downstream IPs, and often suffer from poor signal-to-noise ratios due to the transient nature of IP3. The authors have developed a miniaturized, anion-exchange chromatography method for measuring inositol phosphate accumulation in cells that takes advantage of signal amplification achieved through measuring IP3and downstream IPs. This assay uses centrifugation of 96-well-formatted anion-exchange mini-columns for the isolation of radiolabeled inositol phosphates from cell extracts, followed by low-background dry-scintillation counting. This improved assay method measures receptor-mediated IP accumulation with signal-to-noise and pharmacological values comparable to the classical large-volume, column-based methods. Assay validation data for recombinant muscarinic receptor 1, galanin receptor 2, and rat astrocyte metabotropic glutamate receptor 5 are presented. This miniaturized protocol reduces reagent usage and assay time as compared to large-column methods and is compatible with standard 96-well scintillation counters.
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MESH Headings
- Animals
- Astrocytes/metabolism
- Base Sequence
- CHO Cells
- Cell Line
- Chromatography, Ion Exchange/instrumentation
- Chromatography, Ion Exchange/methods
- Cricetinae
- DNA, Complementary/genetics
- Humans
- Inositol 1,4,5-Trisphosphate
- Inositol Phosphates/analysis
- Inositol Phosphates/metabolism
- Miniaturization/instrumentation
- Miniaturization/methods
- Rats
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Metabotropic Glutamate 5
- Receptor, Muscarinic M1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Metabotropic Glutamate/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Signal Transduction
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Affiliation(s)
- Elfrida R Benjamin
- Purdue Pharma Discovery Research, 6 Cedarbrook Drive, Cranbury, NJ 08512, USA.
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25
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Kerr N, Holmes FE, Hobson SA, Vanderplank P, Leard A, Balthasar N, Wynick D. The generation of knock-in mice expressing fluorescently tagged galanin receptors 1 and 2. Mol Cell Neurosci 2015; 68:258-71. [PMID: 26292267 PMCID: PMC4604734 DOI: 10.1016/j.mcn.2015.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/06/2015] [Accepted: 08/10/2015] [Indexed: 12/12/2022] Open
Abstract
The neuropeptide galanin has diverse roles in the central and peripheral nervous systems, by activating the G protein-coupled receptors Gal1, Gal2 and the less studied Gal3 (GalR1-3 gene products). There is a wealth of data on expression of Gal1-3 at the mRNA level, but not at the protein level due to the lack of specificity of currently available antibodies. Here we report the generation of knock-in mice expressing Gal1 or Gal2 receptor fluorescently tagged at the C-terminus with, respectively, mCherry or hrGFP (humanized Renilla green fluorescent protein). In dorsal root ganglia (DRG) neurons expressing the highest levels of Gal1-mCherry, localization to the somatic cell membrane was detected by live-cell fluorescence and immunohistochemistry, and that fluorescence decreased upon addition of galanin. In spinal cord, abundant Gal1-mCherry immunoreactive processes were detected in the superficial layers of the dorsal horn, and highly expressing intrinsic neurons of the lamina III/IV border showed both somatic cell membrane localization and outward transport of receptor from the cell body, detected as puncta within cell processes. In brain, high levels of Gal1-mCherry immunofluorescence were detected within thalamus, hypothalamus and amygdala, with a high density of nerve endings in the external zone of the median eminence, and regions with lesser immunoreactivity included the dorsal raphe nucleus. Gal2-hrGFP mRNA was detected in DRG, but live-cell fluorescence was at the limits of detection, drawing attention to both the much lower mRNA expression than to Gal1 in mice and the previously unrecognized potential for translational control by upstream open reading frames (uORFs).
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MESH Headings
- Animals
- Brain/metabolism
- Cells, Cultured
- Ganglia, Spinal/cytology
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Mice
- Mice, Transgenic
- Microscopy, Confocal
- Neurons/physiology
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Spinal Cord/metabolism
- Red Fluorescent Protein
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Affiliation(s)
- Niall Kerr
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Fiona E Holmes
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Sally-Ann Hobson
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Penny Vanderplank
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Alan Leard
- Wolfson Bioimaging Facility, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Nina Balthasar
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - David Wynick
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK.
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26
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Misawa K, Misawa Y, Kondo H, Mochizuki D, Imai A, Fukushima H, Uehara T, Kanazawa T, Mineta H. Aberrant methylation inactivates somatostatin and somatostatin receptor type 1 in head and neck squamous cell carcinoma. PLoS One 2015; 10:e0118588. [PMID: 25734919 PMCID: PMC4348545 DOI: 10.1371/journal.pone.0118588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/21/2015] [Indexed: 01/16/2023] Open
Abstract
PURPOSE The aim of this study was to define somatostatin (SST) and somatostatin receptor type 1 (SSTR1) methylation profiles for head and neck squamous cell carcinoma (HNSCC) tumors at diagnosis and follow up and to evaluate their prognostic significance and value as a biomarker. METHODS Gene expression was measured by quantitative RT-PCR. Promoter methylation status was determined by quantitative methylation-specific PCR (Q-MSP) in HNSCC. RESULTS Methylation was associated with transcription inhibition. SST methylation in 81% of HNSCC tumor specimens significantly correlated with tumor size (P = 0.043), stage (P = 0.008), galanin receptor type 2 (GALR2) methylation (P = 0.041), and tachykinin-1 (TAC1) (P = 0.040). SSTR1 hypermethylation in 64% of cases was correlated with tumor size (P = 0.037), stage (P = 0.037), SST methylation (P < 0.001), and expression of galanin (P = 0.03), GALR2 (P = 0.014), TAC1 (P = 0.023), and tachykinin receptor type 1 (TACR1) (P = 0.003). SST and SSTR1 promoter hypermethylation showed highly discriminating receiver operator characteristic curve profiles, which clearly distinguished HNSCC from adjacent normal mucosal tissues. Concurrent hypermethylation of galanin and SSTR1 promoters correlated with reduced disease-free survival (log-rank test, P = 0.0001). Among patients with oral cavity and oropharynx cancer, methylation of both SST and SSTR1 promoters correlated with reduced disease-free survival (log-rank test, P = 0.028). In multivariate logistic-regression analysis, concomitant methylation of galanin and SSTR1 was associated with an odds ratio for recurrence of 12.53 (95% CI, 2.62 to 59.8; P = 0.002). CONCLUSIONS CpG hypermethylation is a likely mechanism of SST and SSTR1 gene inactivation, supporting the hypothesis that SST and SSTR1 play a role in the tumorigenesis of HNSCC and that this hypermethylation may serve as an important biomarker.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Carcinoma, Squamous Cell/diagnosis
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/mortality
- Carcinoma, Squamous Cell/pathology
- CpG Islands
- DNA Methylation
- Female
- Galanin/genetics
- Galanin/metabolism
- Gene Expression Regulation, Neoplastic
- Head and Neck Neoplasms/diagnosis
- Head and Neck Neoplasms/genetics
- Head and Neck Neoplasms/mortality
- Head and Neck Neoplasms/pathology
- Humans
- Male
- Middle Aged
- Mouth Neoplasms/diagnosis
- Mouth Neoplasms/genetics
- Mouth Neoplasms/mortality
- Mouth Neoplasms/pathology
- Neoplasm Staging
- Odds Ratio
- Oropharyngeal Neoplasms/diagnosis
- Oropharyngeal Neoplasms/genetics
- Oropharyngeal Neoplasms/mortality
- Oropharyngeal Neoplasms/pathology
- Promoter Regions, Genetic
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
- Retrospective Studies
- Risk Factors
- Somatostatin/genetics
- Somatostatin/metabolism
- Squamous Cell Carcinoma of Head and Neck
- Survival Analysis
- Tachykinins/genetics
- Tachykinins/metabolism
- Transcription, Genetic
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Affiliation(s)
- Kiyoshi Misawa
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
- * E-mail:
| | - Yuki Misawa
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Haruki Kondo
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Daiki Mochizuki
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Atsushi Imai
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Hirofumi Fukushima
- Department of Head and Neck, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Takayuki Uehara
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate school of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Takeharu Kanazawa
- Department of Otolaryngology/Head and Neck Surgery, Jichi Medical University, Shimotsuke, Japan
| | - Hiroyuki Mineta
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
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Kim DK, Yun S, Son GH, Hwang JI, Park CR, Kim JI, Kim K, Vaudry H, Seong JY. Coevolution of the spexin/galanin/kisspeptin family: Spexin activates galanin receptor type II and III. Endocrinology 2014; 155:1864-73. [PMID: 24517231 DOI: 10.1210/en.2013-2106] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The novel neuropeptide spexin (SPX) was discovered using bioinformatics. The function of this peptide is currently under investigation. Here, we identified SPX along with a second SPX gene (SPX2) in vertebrate genomes. Syntenic analysis and relocating SPXs and their neighbor genes on reconstructed vertebrate ancestral chromosomes revealed that SPXs reside in the near vicinity of the kisspeptin (KISS) and galanin (GAL) family genes on the chromosomes. Alignment of mature peptide sequences showed some extent of sequence similarity among the 3 peptide groups. Gene structure analysis indicated that SPX is more closely related to GAL than KISS. These results suggest that the SPX, GAL, and KISS genes arose through local duplications before 2 rounds (2R) of whole-genome duplication. Receptors of KISS and GAL (GAL receptor [GALR]) are phylogenetically closest among rhodopsin-like G protein-coupled receptors, and synteny revealed the presence of 3 distinct receptor families KISS receptor, GALR1, and GALR2/3 before 2R. A ligand-receptor interaction study showed that SPXs activate human, Xenopus, and zebrafish GALR2/3 family receptors but not GALR1, suggesting that SPXs are natural ligands for GALR2/3. Particularly, SPXs exhibited much higher potency toward GALR3 than GAL. Together, these results identify the coevolution of SPX/GAL/KISS ligand genes with their receptor genes. This study demonstrates the advantage of evolutionary genomics to explore the evolutionary relationship of a peptide gene family that arose before 2R by local duplications.
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MESH Headings
- Animals
- Chromosome Mapping
- Databases, Nucleic Acid
- Databases, Protein
- Evolution, Molecular
- Galanin/chemistry
- Galanin/genetics
- Galanin/metabolism
- Gene Duplication
- HEK293 Cells
- Humans
- Kisspeptins/chemistry
- Kisspeptins/genetics
- Kisspeptins/metabolism
- Ligands
- Neuropeptides/chemistry
- Neuropeptides/genetics
- Neuropeptides/metabolism
- Peptide Hormones/chemistry
- Peptide Hormones/genetics
- Peptide Hormones/metabolism
- Phylogeny
- Protein Isoforms/chemistry
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/chemistry
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/chemistry
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/agonists
- Receptor, Galanin, Type 3/chemistry
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Kisspeptin-1
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Sequence Alignment
- Synteny
- Zebrafish Proteins/chemistry
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
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Affiliation(s)
- Dong-Kyu Kim
- Graduate School of Medicine (D.-K.K., S.Y., G.H.S., J.-I.H., C.R.P., J.Y.S.), Korea University, Seoul 136-705, Republic of Korea; Department of Life Science (J.I.K.), Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea; School of Biological Sciences (K.K.), Seoul National University, Seoul 151-742, Republic of Korea; and Laboratory of Neuronal and Neuroendocrine Differentiation and Communication (H.V.), Inserm U982, University of Rouen, 76821 Mont-St-Aignan, France
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28
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Ho JCW, Jacobs T, Wang Y, Leung FC. Identification and characterization of the chicken galanin receptor GalR2 and a novel GalR2-like receptor (GalR2-L). Gen Comp Endocrinol 2012; 179:305-12. [PMID: 22982974 DOI: 10.1016/j.ygcen.2012.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/29/2012] [Accepted: 09/02/2012] [Indexed: 01/13/2023]
Abstract
In mammals, the neuropeptide galanin exerts a variety of physiological roles in the neuroendocrine system through its interactions with three galanin receptor subtypes (GalR1, GalR2 and GalR3). However, little is known about the characteristics of galanin receptors in birds, and it is only recently that avian GalR1 and a novel GalR1-like receptor were first identified in chickens. In this study, we report the cDNA cloning and characterization of the other two chicken galanin receptors, the galanin type II receptor (cGalR2) and a novel GalR2-like receptor (GalR2-L), which share high degrees of similarity in sequence identity, gene structure and signaling properties. cGalR2 and cGalR2-L cDNAs encode two putative receptors of 371 and 370 amino acids, in which they show considerable amino acid sequence identities (65-67%, and 53-55%, respectively) with the mammalian GalR2. RT-PCR assays revealed that cGalR2 and cGalR2-L mRNA were widely expressed in the adult chicken tissues including the whole brain, intestine, lung, ovary, pituitary and different regions of the oviduct. As assayed with different luciferase reporter systems, chicken galanin (cGal 1-29) and human galanin-like peptide (hGALP 1-60) were demonstrated to stimulate the luciferase activities in Chinese hamster ovary cells expressing cGalR2 and cGalR2-L through the activations of cAMP/PKA, Ca(2+)/calcineurin and MAPK/ERK signaling pathways, hence suggesting that both receptors are functionally coupled to the G(s) and G(q) proteins. Furthermore, the previously identified cGalR1 and cGalR1-L were found to be solely coupled to the G(i/o) proteins, and the hGALP (1-60) exhibited only a low potency to cGalR1, cGalR1-L, cGalR2 and cGalR2-L activations.
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Affiliation(s)
- John Chi Wang Ho
- School of Biological Sciences, The University of Hong Kong, Hong Kong
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29
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Holmes FE, Armenaki A, Iismaa TP, Einstein EB, Shine J, Picciotto MR, Wynick D, Zachariou V. Galanin negatively modulates opiate withdrawal via galanin receptor 1. Psychopharmacology (Berl) 2012; 220:619-25. [PMID: 21969124 PMCID: PMC3324978 DOI: 10.1007/s00213-011-2515-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 09/15/2011] [Indexed: 12/15/2022]
Abstract
RATIONALE The neuropeptide galanin has been shown to modulate opiate dependence and withdrawal. These effects could be mediated via activation of one or more of the three distinct G protein-coupled receptors, namely galanin receptors 1 (GalR1), 2 (GalR2), and 3 (GalR3). OBJECTIVES In this study, we used several transgenic mouse lines to further define the mechanisms underlying the role played by galanin and its receptors in the modulation of morphine dependence. First, transgenic mice expressing β-galactosidase under the control of the galanin promoter were used to assess the regulation of galanin expression in response to chronic morphine administration and withdrawal. Next, the behavioral responses to chronic morphine administration and withdrawal were tested in mice that over-express galanin, lack the GalR1 gene, or lack the GalR2 gene. METHODS Transgenic and matched wild-type mice were given increasing doses of morphine followed by precipitation of withdrawal by naloxone and behavioral responses to withdrawal were assessed. RESULTS Both morphine administration and withdrawal increased galanin gene transcription in the locus coeruleus (LC). Increasing galanin levels in the brain reduced signs of opiate withdrawal. Mice lacking GalR1 undergo more severe opiate withdrawal, whereas mice lacking GalR2 show no significant difference in withdrawal signs, compare with matched wild-type controls. CONCLUSIONS Opiate administration and withdrawal increase galanin expression in the LC. Galanin opposes the actions of morphine which leads to opiate dependence and withdrawal, an effect that is mediated via GalR1.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Brain/drug effects
- Brain/metabolism
- Galanin/metabolism
- Gene Expression Regulation
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Morphine/administration & dosage
- Morphine/adverse effects
- Naloxone/pharmacology
- Narcotic Antagonists/pharmacology
- Opioid-Related Disorders/physiopathology
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Substance Withdrawal Syndrome/physiopathology
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Affiliation(s)
- Fiona E Holmes
- Schools of Physiology and Pharmacology and Clinical Sciences, University of Bristol, Bristol, UK
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30
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Holm L, Hilke S, Adori C, Theodorsson E, Hökfelt T, Theodorsson A. Changes in galanin and GalR1 gene expression in discrete brain regions after transient occlusion of the middle cerebral artery in female rats. Neuropeptides 2012; 46:19-27. [PMID: 22197078 DOI: 10.1016/j.npep.2011.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/27/2011] [Accepted: 11/27/2011] [Indexed: 11/16/2022]
Abstract
Injury to neurons results in up-regulation of galanin in some central and peripheral systems, and it has been suggested that this neuropeptide may play a protective and trophic role, primarily mediated by galanin receptor 2 (GalR2). The objective of the present study was to investigate galanin, GalR1, GalR2 and GalR3 gene expression in the female rat brain 7 days after a 60-min unilateral occlusion of the middle cerebral artery followed by reperfusion. Quantitative real-time PCR was employed in punch-biopsies from the locus coeruleus, somatosensory cortex and dorsal hippocampal formation, including sham-operated rats as controls. Galanin gene expression showed a ∼2.5-fold increase and GalR1 a ∼1.5-fold increase in the locus coeruleus of the ischemic hemisphere compared to the control side. Furthermore, the GalR1 mRNA levels decreased by 35% in somatosensory cortex of the ischemic hemisphere. Immunohistochemical analysis indicated a depletion of galanin from cell bodies and dendrites in the locus coeruleus after middle cerebral artery occlusion. The present results suggest that a stroke-induced forebrain lesion up-regulates synthesis of galanin and GalR1 in the locus coeruleus, a noradrenergic cell group projecting to many forebrain areas, including cortex and the hippocampal formation. These results support the notion that galanin may play a role in the response of the central nervous system to injury.
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MESH Headings
- Animals
- Brain/metabolism
- Brain/pathology
- Disease Models, Animal
- Female
- Galanin/genetics
- Galanin/metabolism
- Gene Expression
- Infarction, Middle Cerebral Artery/genetics
- Infarction, Middle Cerebral Artery/metabolism
- Rats
- Rats, Sprague-Dawley
- Real-Time Polymerase Chain Reaction
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/genetics
- Reperfusion Injury/genetics
- Reperfusion Injury/pathology
- Up-Regulation/physiology
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Affiliation(s)
- Lovisa Holm
- Division of Clinical Chemistry, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, County Council of Östergötland, Linköping, Sweden
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31
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Christiansen SH. Regulation of the galanin system in the brainstem and hypothalamus by electroconvulsive stimulation in mice. Neuropeptides 2011; 45:337-41. [PMID: 21820174 DOI: 10.1016/j.npep.2011.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 06/27/2011] [Accepted: 07/12/2011] [Indexed: 12/01/2022]
Abstract
Induction of seizures by electroconvulsive stimulation (ECS) is amongst the most efficacious treatments for major depression. However, the working mechanism by which ECS exerts its antidepressant effects remains elusive. The galanin system is regulated by ECS in seizure-prone brain regions and has been shown to modulate depression-like behaviour. To further explore its potential role in the antidepressant effects of ECS the galanin system was investigated by in situ hybridisation and [(125)I]-galanin receptor binding during repeated ECS in the locus coeruleus, dorsal raphe and discrete nuclei of the hypothalamus. Adult mice were treated with ECS once daily for 14 consecutive days, a paradigm previously shown to exert antidepressant-like effects. Significant increases in galanin transcription were found in the locus coeruleus and dorsomedial nuclei of the hypothalamus. In addition, GalR2 mRNA levels in the ventro- and dorsomedial nuclei of the hypothalamus were upregulated whereas no GalR1 mRNA upregulation was observed. [(125)I]-galanin receptor binding was downregulated in the ventromedial nuclei of the hypothalamus and dorsal raphe. These data show that the galanin system is regulated by repeated ECS in brain regions involved in monoaminergic neurotransmission and stress modulation thus indicating a possible role of the galanin system in the therapeutic effects of ECS.
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Affiliation(s)
- S H Christiansen
- Psychiatric Centre Copenhagen, Rigshospitalet O-6102, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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Louridas M, Letourneau S, Lautatzis ME, Vrontakis M. Galanin is highly expressed in bone marrow mesenchymal stem cells and facilitates migration of cells both in vitro and in vivo. Biochem Biophys Res Commun 2009; 390:867-71. [PMID: 19840773 DOI: 10.1016/j.bbrc.2009.10.064] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 10/13/2009] [Indexed: 01/16/2023]
Abstract
Galanin peptide has recently been found to be highly abundant in early embryonic mouse mesenchyme, while galanin and its receptors are expressed in embryonic mouse stem cells. Bone marrow mesenchymal stem cells (BMMSCs) represent the primary source for adult stem cell therapy. In this study we examined the abundance of galanin and its receptors in BMMSCs and evaluated its possible function. Galanin mRNA and protein were highly expressed in BMMSCs cultures up to four passages, while among the three galanin receptor subtypes (GalR1, GalR2, and GalR3) only GalR2 and to a lesser extent GalR3 were expressed. Using chemotaxis and wound assays we found that galanin protein increased the migration of BMMSCs. Furthermore, increased serum galanin levels in a galanin transgenic model enhanced the mobilization (homing) of injected BMMSCs in vivo. These data suggest a role for galanin in BMMSC migration, probably through activation of the GalR2 receptor.
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Affiliation(s)
- Marisa Louridas
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Man, Canada
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Kanazawa T, Kommareddi PK, Iwashita T, Kumar B, Misawa K, Misawa Y, Jang I, Nair TS, Iino Y, Carey TE. Galanin receptor subtype 2 suppresses cell proliferation and induces apoptosis in p53 mutant head and neck cancer cells. Clin Cancer Res 2009; 15:2222-30. [PMID: 19276245 PMCID: PMC3315370 DOI: 10.1158/1078-0432.ccr-08-2443] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Galanin and its three receptors (GALR1-3) are expressed in many normal tissues, but silenced in some tumors. Contradictory roles for galanin and its receptors in various tumors have been reported. To understand their function, investigations of individual galanin receptors are necessary. In head and neck squamous carcinoma cells (HNSCC) with silenced GALR1 and GALR2, we showed that reexpressed GALR1 suppresses tumor cell proliferation via Erk1/2-mediated effects on cdk inhibitors and cyclin D1. Others showed that GALR2 could induce apoptosis in neuroblastoma cells with wild-type p53, whereas GALR2 stimulated proliferation in small cell lung cancer. In this study, we investigated the role of GALR2 in HNSCC cells that have mutant p53 and do not express GALR1. EXPERIMENTAL DESIGN UM-SCC-1, a human oral carcinoma cell line with a splice site mutation causing a 46-bp p53 off-frame deletion, was stably transfected to express GALR2 (UM-SCC-1-GALR2). RESULTS Galanin treatment of UM-SCC-1-GALR2 caused morphologic changes and a marked decrease in cell number that were not observed in UM-SCC-1-mock cells. Galanin and GALR2 resulted in decreased bromodeoxyuridine incorporation, p27(Kip1) and p57(Kip2) up-regulation, and decreased cyclin D1 expression. These effects were similar to GALR1 signaling in HNSCC, but GALR2 also induced caspase-3-dependent apoptosis, which was confirmed by Annexin-V staining and DNA fragmentation analysis. These were not observed with GALR1. CONCLUSION This study shows that GALR2 reexpression can inhibit cell proliferation and induce apoptosis in HNSCC cells with mutant p53. GALR2 may be a feasible target for HNSCC therapy.
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Affiliation(s)
- Takeharu Kanazawa
- Laboratory of Head and Neck Cancer Biology, The University of Michigan, Ann Arbor, Michigan, USA.
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Lu X, Ross B, Sanchez-Alavez M, Zorrilla EP, Bartfai T. Phenotypic analysis of GalR2 knockout mice in anxiety- and depression-related behavioral tests. Neuropeptides 2008; 42:387-97. [PMID: 18554714 PMCID: PMC3399724 DOI: 10.1016/j.npep.2008.04.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 03/20/2008] [Accepted: 04/21/2008] [Indexed: 11/18/2022]
Abstract
Neuropeptide galanin modulates a variety of central nervous system functions by signaling through three G-protein-coupled receptor subtypes, GalR1 through GalR3. Galanin and its receptors are expressed at high levels in the limbic structures of the rodent brain. Intracerebroventricular injection of galanin has been shown to modulate depression and anxiety-like behaviors in the rat. We have previously shown that chronic antidepressant treatments increase the binding of a GalR2-preferring ligand, galanin (2-11), to the dorsal raphe nucleus (DRN) of the rat, which, along with the finding that intra-DRN infusion of galanin (2-11) increases the release of serotonin in the hippocampus, suggests that GalR2 signaling might exert antidepressant-like actions by modulating ascending serotonergic outflow. Recently, two research groups reported their phenotypic analysis of a GalR2 knockout (GalR2KO) mouse line, produced by gene-trapping method and maintained on a 129S1/SvImJ genetic background. The only positive finding in that GalR2KO mouse line was an anxiogenic-like phenotype specific to the elevated plus-maze. Because it is known that genetic background can affect the outcome of behavioral tests, in the present study, we analyzed a separate GalR2KO line, which was produced by targeted deletion and maintained on a C57BL/6 background, using a different set of depression- and anxiety-related tests. GalR2KO mice exhibited a more persistent depressive-like phenotype in the learned helplessness paradigm as well as increased immobility in the tail suspension test when results from the present studies were combined by fixed effect meta-analysis with that reported by Gottsch and colleagues. GalR2KO mutants showed anxiety-like behavior comparable to wild-type littermates in the elevated plus-maze, open-field, and light-dark transfer tests. The present findings are consistent with a predicted antidepressant-like effect of GalR2 signaling, suggesting that GalR2 might be a valid drug target for depressive disorders.
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Affiliation(s)
- Xiaoying Lu
- The Harold L Dorris Neurological Institute, Department of Molecular and Integrative Neurosciences, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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35
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Ye YL, Qi YT, Shan L, Zou LJ, Gao LC, Yuan CG. [The expression of galanin and galanin receptor-2 in the brain of chronic stress model of depression]. Fen Zi Xi Bao Sheng Wu Xue Bao 2007; 40:380-386. [PMID: 18198579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The expression of galanin and galanin receptor-2 in hippocampus and dorsal raphe nucleus of depression model was studied. The chronic stress rat model was adopted as the modal of depression. Open-field test was used to observe the transformation of their behavior and HPLC-EC was employed to analysis the level of blood serum cortisol. The method of in situ hybridization was used for testing the expression of Galanin and galanin receptor-2 in hippocampus and dorsal raphe nucleus and the method of RT-PCR was used to further analysis of the expression. The results showed that the locomotion activity decreased extremely after chronic stress, but the level of serum cortisol increased evidently. The expression of Galanin and its receptor-2 in hippocampus and dorsal raphe nucleus increased obviously. The higher expression for galanin and galanin receptor-2 in some brain area suggested that galanin probably takes part in the modulation of the function of neurons during the stress process.
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Affiliation(s)
- Yi Lei Ye
- School of Life Science, East China Normal University, Shanghai 200062, China
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36
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Chambers G, Whitelaw CM, Robinson JE, Evans NP. Distribution of galanin receptor-2 immunoreactive neurones in the ovine hypothalamus: no evidence for involvement in the control of gonadotrophin-releasing hormone secretion. J Neuroendocrinol 2007; 19:966-73. [PMID: 18001326 DOI: 10.1111/j.1365-2826.2007.01609.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Galanin is a small neuropeptide that mediates its effects via three receptor isoforms: galanin receptor-1, galanin receptor-2 and galanin receptor-3 (Gal-R1, Gal-R2 and Gal-R3). Galanin is thought to be an important intermediate in signalling in the hypothalamic-pituitary-gonadal axis and has been widely detected in the ovine hypothalamus. The expression of galanin and Gal-R1 has been reported to fluctuate during the reproductive cycle. Although the distribution of Gal-R1 has been determined in the ovine hypothalamus, the distribution of Gal-R2 was hitherto unknown. Using immunohistological and immunofluorescence techniques, we have mapped the distribution of Gal-R2 in the ovine hypothalamus, collected during the follicular phase of the oestrous cycle and examined colocalisation of Gal-R2 with oestrogen receptor alpha (ERalpha) and gonadotrophin-releasing hormone (GnRH). Gal-R2 was expressed in several regions of the hypothalamus (supraoptic nucleus, paraventricular nucleus, ventromedial nucleus, arcuate nucleus) but not as widely expressed as Gal-R1. Areas of Gal-R2 expression overlapped with those reported for Gal-R1. We observed that, in certain defined regions of the hypothalamus, up to 50% of neurones that express Gal-R2 also express ERalpha. No neurones coexpressed Gal-R2 and GnRH. Thus, we conclude that, in follicular phase animals, this receptor plays little or no role in direct intermediary signal transmission in GnRH-mediated control of the reproductive cycle.
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Affiliation(s)
- G Chambers
- Division of Cell Sciences, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, UK
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37
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Page AJ, Slattery JA, Brierley SM, Jacoby AS, Blackshaw LA. Involvement of galanin receptors 1 and 2 in the modulation of mouse vagal afferent mechanosensitivity. J Physiol 2007; 583:675-84. [PMID: 17627995 PMCID: PMC2277026 DOI: 10.1113/jphysiol.2007.135939] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
It is established that the gut peptide galanin reduces neuronal excitability via galanin receptor subtypes GALR1 and GALR3 and increases excitability via subtype GALR2. We have previously shown that galanin potently reduces mechanosensitivity in the majority of gastro-oesophageal vagal afferents, and potentiates sensitivity in a minority. These actions may have implications for therapeutic inhibition of gut afferent signalling. Here we investigated which galanin receptors are likely to mediate these effects. We performed quantitative RT-PCR on RNA from vagal (nodose) sensory ganglia, which indicated that all three GALR subtypes were expressed at similar levels. The responses of mouse gastro-oesophageal vagal afferents to graded mechanical stimuli were investigated before and during application of galanin receptor ligands to their peripheral endings. Two types of vagal afferents were tested: tension receptors, which respond to circumferential tension, and mucosal receptors which respond only to mucosal stroking. Galanin induced potent inhibition of mechanosensitivity in both types of afferents. This effect was totally lost in mice with targeted deletion of Galr1. The GALR1/2 agonist AR-M961 caused inhibition of mechanosensitivity in Galr1+/+ mice, but this was reversed to potentiation in Galr1-/- mice, indicating a minor role for GALR2 in potentiation of vagal afferents. We observed no functional evidence of GALR3 involvement, despite its expression in nodose ganglia. The current study highlights the complex actions of galanin at different receptor subtypes exhibiting parallels with the function of galanin in other systems.
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MESH Headings
- Animals
- Esophagus/innervation
- Galanin/metabolism
- Galanin/pharmacology
- Indoles/pharmacology
- Mechanotransduction, Cellular/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Nodose Ganglion/metabolism
- Peptide Fragments/pharmacology
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/deficiency
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/antagonists & inhibitors
- Receptor, Galanin, Type 3/metabolism
- Stomach/innervation
- Stress, Mechanical
- Vagus Nerve/cytology
- Vagus Nerve/drug effects
- Vagus Nerve/metabolism
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Affiliation(s)
- Amanda J Page
- Nerve Gut Research Laboratory, Department of Gastroenterology and Hepatology, Hanson Institute, Royal Adelaide Hospital, Adelaide, Australia.
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38
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Abstract
Expression of the neuropeptide galanin is up-regulated in many brain regions following nerve injury and in the basal forebrain of patients with Alzheimer's disease. We have previously demonstrated that galanin modulates hippocampal neuronal survival, although it was unclear which receptor subtype(s) mediates this effect. Here we report that the protective role played by galanin in hippocampal cultures is abolished in animals carrying a loss-of-function mutation in the second galanin receptor subtype (GalR2-MUT). Exogenous galanin stimulates the phosphorylation of the serine/threonine kinase Akt and extracellular signal-regulated kinase (ERK) in wild-type (WT) cultures by 435 +/- 5% and 278 +/- 2%, respectively. The glutamate-induced activation of Akt was abolished in cultures from galanin knockout animals, and was markedly attenuated in GalR2-MUT animals, compared with WT controls. In contrast, similar levels of glutamate-induced ERK activation were observed in both loss-of-function mutants, but were further increased in galanin over-expressing animals. Using specific inhibitors of either ERK or Akt confirms that a GalR2-dependent modulation in the activation of the Akt and ERK signalling pathways contributes to the protective effects of galanin. These findings imply that the rise in endogenous galanin observed either after brain injury or in various disease states is an adaptive response that reduces apoptosis by the activation of GalR2, and hence Akt and ERK.
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MESH Headings
- Animals
- Brain Damage, Chronic/genetics
- Brain Damage, Chronic/metabolism
- Brain Damage, Chronic/physiopathology
- Cytoprotection/drug effects
- Cytoprotection/genetics
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Extracellular Signal-Regulated MAP Kinases/drug effects
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Galanin/metabolism
- Galanin/pharmacology
- Glutamic Acid/metabolism
- Glutamic Acid/pharmacology
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hippocampus/physiopathology
- Male
- Mice
- Mice, Knockout
- Nerve Degeneration/genetics
- Nerve Degeneration/metabolism
- Nerve Degeneration/physiopathology
- Neurodegenerative Diseases/genetics
- Neurodegenerative Diseases/metabolism
- Neurodegenerative Diseases/physiopathology
- Neurons/drug effects
- Neurons/metabolism
- Organ Culture Techniques
- Proto-Oncogene Proteins c-akt/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Up-Regulation/drug effects
- Up-Regulation/physiology
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Affiliation(s)
- Caroline R Elliott-Hunt
- Departments of Pharmacology and Clinical Sciences South Bristol, Bristol University, Bristol, UK
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39
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Andreis PG, Malendowicz LK, Rebuffat P, Spinazzi R, Ziolkowska A, Nussdorfer GG. Galanin enhances corticosterone secretion from dispersed rat adrenocortical cells through the activation of GAL-R1 and GAL-R2 receptors coupled to the adenylate cyclase-dependent signaling cascade. Int J Mol Med 2007; 19:149-55. [PMID: 17143559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
Galanin is a regulatory peptide, which acts via three subtypes of receptors, named GAL-R1, GAL-R2 and GAL-R3. Reverse transcription-polymerase chain reaction demonstrated the expression of GAL-R1 and GAL-R2, but not GAL-R3 mRNAs in dispersed rat adrenal zona fasciculata-reticularis (inner) cells. The immuno-blockade of GAL-R1 and GAL-R2, but not GAL-R3, decreased the binding of [3H]galanin to dispersed cells, a complete inhibition being obtained only by the simultaneous blockade of both receptor subtypes. Galanin stimulated corticosterone and cyclic-AMP release from dispersed inner rat adrenocortical cells, while inositol triphosphate production was not affected. Again these responses to galanin were reversed by both the GAL-R1 and GAL-R2, but not the GAL-R3 immuno-blockade. The adenylate cyclase inhibitor SQ-22536 and the protein kinase (PK) A inhibitor H-89 abolished the corticosterone response of dispersed cells to galanin, while the phospholipase C inhibitor U-73122 and the PKC inhibitor calphostin-C were ineffective. We conclude that rat inner adrenocortical cells express GAL-R1 and GAL-R2 as mRNA and protein, and galanin stimulates corticosterone secretion acting via these receptor subtypes which are both coupled to the adenylate cyclase/PKA-dependent signaling pathway.
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Affiliation(s)
- Paola G Andreis
- Department of Anatomy and Physiology, Section of Anatomy, University of Padua, I-35121 Padua, Italy
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40
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Brumovsky P, Mennicken F, O'donnell D, Hökfelt T. Differential distribution and regulation of galanin receptors- 1 and -2 in the rat lumbar spinal cord. Brain Res 2006; 1085:111-20. [PMID: 16626647 DOI: 10.1016/j.brainres.2006.02.088] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 02/22/2006] [Accepted: 02/22/2006] [Indexed: 12/17/2022]
Abstract
The expression of the galanin receptor-1 and -2 (Gal(1) and Gal(2)) messenger ribonucleic acids (mRNAs) was studied in the lower spinal cord of rat by means of in situ hybridization, using ribonucleic acid probes (riboprobes). Naïve rats as well as rats with unilateral axotomy of the sciatic nerve or unilateral inflammation of the hindpaw were analyzed. In naïve rats, numerous Gal(1) mRNA-positive (+) neurons were detected in lamina (L) I-III. In addition, several Gal(1) mRNA(+) neurons were seen in deeper layers, including the ventral horns, area X, and the lateral spinal nucleus. In contrast, few and comparatively weakly labeled Gal(2) mRNA(+) neurons were observed, mostly in the ventral horns and in area X, with fewer in the dorsal horn and in the sympathetic and parasympathetic intermediate lateral cell columns. Axotomy induced a strong increase in intensity and number of Gal(2) mRNA(+) motoneurons ipsilateral to the lesion. In contrast, nerve cut or hindpaw inflammation did not alter the expression of Gal(1) or Gal(2) in the dorsal horn. The present (and previous) results suggest that galanin, acting through Gal(1) and Gal(2) receptors, has a modulatory role on spinal excitability, not only via interneurons in superficial dorsal horn, but also on neurons in deep layers and area X, as well as on the sympathetic and parasympathetic outflow. Furthermore, the nerve injury-induced Gal(2) upregulation in motor neurons suggests a role for galanin in survival/regeneration mechanisms.
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Affiliation(s)
- Pablo Brumovsky
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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41
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Mazarati AM, Baldwin RA, Shinmei S, Sankar R. In vivo interaction between serotonin and galanin receptors types 1 and 2 in the dorsal raphe: implication for limbic seizures. J Neurochem 2005; 95:1495-503. [PMID: 16219029 PMCID: PMC1343489 DOI: 10.1111/j.1471-4159.2005.03498.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The neuropeptide galanin suppresses seizure activity in the hippocampus by inhibiting glutamatergic neurotransmission. Galanin may also modulate limbic seizures through interaction with other neurotransmitters in neuronal populations that project to the hippocampus. We examined the role of galanin receptors types 1 and 2 in the dorsal raphe (DR) in the regulation of serotonergic transmission and limbic seizures. Infusion of a mixed agonist of galanin receptors types 1 and 2 [galanin (1-29)] into the DR augmented the severity of limbic seizures in both rats and wild-type mice and concurrently reduced serotonin concentration in the DR and hippocampus as measured by immunofluorescence or HPLC. In contrast, injection of the galanin receptor type 2 agonist galanin (2-11) mitigated the severity of seizures in both species and increased serotonin concentration in both areas. Injection of both galanin fragments into the DR of galanin receptor type 1 knockout mice exerted anticonvulsant effects. Both the proconvulsant activity of galanin (1-29) and seizure suppression by galanin (2-11) were abolished in serotonin-depleted animals. Our data indicate that, in the DR, galanin receptors types 1 and 2 modulate serotonergic transmission in a negative and a positive fashion, respectively, and that these effects translate into either facilitation or inhibition of limbic seizures.
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MESH Headings
- Animals
- Cell Count/methods
- Dose-Response Relationship, Drug
- Drug Interactions
- Electric Stimulation/adverse effects
- Electroencephalography/methods
- Galanin/pharmacology
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hippocampus/radiation effects
- Immunohistochemistry/methods
- Male
- Mice
- Mice, Knockout
- Norepinephrine/metabolism
- Peptide Fragments/pharmacology
- Raphe Nuclei/drug effects
- Raphe Nuclei/metabolism
- Rats
- Rats, Wistar
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/deficiency
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/metabolism
- Seizures/etiology
- Seizures/metabolism
- Serotonin/metabolism
- Serotonin Agents/pharmacology
- p-Chloroamphetamine/pharmacology
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Affiliation(s)
- Andrey M Mazarati
- Department of Pediatrics, Division of Pediatric Neurology, D. Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
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42
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Ding X, MacTavish D, Kar S, Jhamandas JH. Galanin attenuates beta-amyloid (Abeta) toxicity in rat cholinergic basal forebrain neurons. Neurobiol Dis 2005; 21:413-20. [PMID: 16246567 DOI: 10.1016/j.nbd.2005.08.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 08/05/2005] [Accepted: 08/16/2005] [Indexed: 01/05/2023] Open
Abstract
In brains of Alzheimer's disease (AD) patients, expression of the neuropeptide galanin is significantly upregulated and galanin-immunoreactive fibers hypertrophy and hyperinnervate cholinergic neurons of the basal forebrain. However, the role of galanin in AD, whether it is detrimental or neuroprotective, remains controversial. In this study, using primary cultured neurons from the rat basal forebrain, we show that pretreatment with galanin protects cholinergic neurons against beta-amyloid-induced apoptotic cell death as judged by visual observation, MTT assay, Live/dead cell assay, TUNEL and cleaved caspase-3 staining. These effects are mimicked by the galanin receptor 2 (GALR2) agonist, AR-M1896. Western blot analysis revealed Abeta-induced decrease in phospho-PKC and phospho-Akt levels was reversed by galanin. Galanin also attenuated cleavage of caspases-3 and -9 following exposure to Abeta. These findings support a neuroprotective role for galanin and may have implications for development of compounds based on this peptide to treat AD.
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Affiliation(s)
- Xiling Ding
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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43
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He B, Counts SE, Perez SE, Hohmann JG, Koprich JB, Lipton JW, Steiner RA, Crawley JN, Mufson EJ. Ectopic galanin expression and normal galanin receptor 2 and galanin receptor 3 mRNA levels in the forebrain of galanin transgenic mice. Neuroscience 2005; 133:371-80. [PMID: 15885921 DOI: 10.1016/j.neuroscience.2005.01.068] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 01/21/2005] [Accepted: 01/25/2005] [Indexed: 10/25/2022]
Abstract
The functional interactions of the neuropeptide galanin (GAL) occur through its binding to three G protein-coupled receptor subtypes: galanin receptor (GALR) 1, GALR2 and GALR3. Previously, we demonstrated that GALR1 mRNA expression was increased in the CA1 region of the hippocampus and discrete hypothalamic nuclei in galanin transgenic (GAL-tg) mice. This observation suggested a compensatory adjustment in cognate receptors in the face of chronic GAL exposure. To evaluate the molecular alterations to GALR2 and GALR3 in the forebrain of GAL overexpressing mice, we performed complementary quantitative, real-time PCR (qPCR), in situ hybridization, and immunohistochemistry in select forebrain regions of GAL-tg mice to characterize the neuronal distribution and magnitude of GAL mRNA and peptide expression and the consequences of genetically manipulating the neuropeptide GAL on the expression of GALR2 and GALR3 receptors. We found that GAL-tg mice displayed dramatic increases in GAL mRNA and peptide in the frontal cortex, posterior cortex, hippocampus, septal diagonal band complex, amygdala, piriform cortex, and olfactory bulb. Moreover, there was evidence for ectopic neuronal GAL expression in forebrain limbic regions that mediate cognitive and affective behaviors, including the piriform and entorhinal cortex and amygdala. Interestingly, regional qPCR analysis failed to reveal any changes in GALR2 or GALR3 expression in the GAL-tg mice, suggesting that, contrary to GALR1, these receptor genes are not under ligand-mediated regulatory control. The GAL-tg mouse model may provide a useful tool for the investigation of GAL ligand-receptor relationships and their role in normal cognitive and affective functions as well as in the onset of neurological disease.
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MESH Headings
- Animals
- Galanin/genetics
- Galanin/metabolism
- Gene Expression Regulation/genetics
- Immunohistochemistry/methods
- In Situ Hybridization/methods
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Prosencephalon/anatomy & histology
- Prosencephalon/metabolism
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
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Affiliation(s)
- B He
- Department of Neurological Sciences, Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, USA
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44
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Hawes JJ, Brunzell DH, Wynick D, Zachariou V, Picciotto MR. GalR1, but not GalR2 or GalR3, levels are regulated by galanin signaling in the locus coeruleus through a cyclic AMP-dependent mechanism. J Neurochem 2005; 93:1168-76. [PMID: 15934937 PMCID: PMC1352153 DOI: 10.1111/j.1471-4159.2005.03105.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The galanin receptors GalR1, GalR2 and GalR3 are widely expressed throughout the mouse brain and are enriched in catecholaminergic nuclei. Here, we show that GalR1 protein levels are regulated by neuronal activity and changes in cAMP levels. GalR1, but not GalR2 or GalR3, is specifically up-regulated in the LC-like Cath.a cell line in a cAMP-dependent manner. GalR1 protein and mRNA levels are also up-regulated in the LC of galanin knockout mice, whereas GalR2 and GalR3 are not. Lack of galanin-maintained cAMP tone in the galanin knockout mouse appears to result in a loss of negative feedback resulting in increased levels of CREB phosphorylation and increased GalR1 expression. These findings suggest that changes in levels of GalR1 may play an important role in modulating signaling events and neuroplasticity underlying physiological functions of the LC.
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MESH Headings
- Animals
- Cell Line
- Cyclic AMP/physiology
- Cyclic AMP Response Element-Binding Protein/metabolism
- Feedback, Physiological
- Galanin/genetics
- Galanin/metabolism
- Locus Coeruleus/metabolism
- Male
- Mice
- Mice, Knockout/genetics
- Phosphorylation
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/metabolism
- Signal Transduction/physiology
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Affiliation(s)
- Jessica J. Hawes
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | | | - David Wynick
- Bristol U, Dept of Medicine, Bristol BS2 8HW, U.K
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45
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Barreda-Gómez G, Giralt MT, Rodríguez-Puertas R. G protein-coupled galanin receptor distribution in the rat central nervous system. Neuropeptides 2005; 39:153-6. [PMID: 15944004 DOI: 10.1016/j.npep.2004.12.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Accepted: 12/02/2004] [Indexed: 11/15/2022]
Abstract
The action of galanin in the central nervous system is mediated by at least three galanin receptor subtypes (GalR1, GalR2 and GalR3) which belong to the family of G protein-coupled receptors. GalR1 and GalR2 are coupled to G(i/o) proteins, although the latter may also be coupled to G(q/11) proteins. The aim of the present study was to identify the anatomical distribution and quantify the density of GalRs coupled to G proteins. The galanin (10(-6) M) stimulated guanosine 5'-(gamma-[35S] thio)triphosphate binding assay was used in tissue sections from the rat brain. Maximal percentages of stimulation over basal levels were found in the anterior olfactory nucleus and in the lateral olfactory tract nucleus ( approximately 54%). High levels of stimulation were recorded in diverse hypothalamic nuclei (16-28%), in the amygdala (central amygdaloid nucleus, 40%), in the spinal trigeminal tract (23%) and in layers 1-2 of the spinal cord (26%). Moderate binding stimulation (5-13%) was observed in thalamus, substantia nigra pars compacta, parabrachial nucleus, locus coeruleus and dorsal raphe nucleus. The lowest stimulation induced by galanin was recorded in diverse areas of the cortex, striatum, hippocampus and substantia nigra pars reticulata. The results show an anatomical distribution similar to that described for GalR1. However, in diverse brain areas, in which a high density of these receptors has previously been reported, only a moderate coupling to G proteins was found. These findings would suggest that the efficacy of galanin to induce an effective coupling of its receptors to G proteins could be different depending on the brain area.
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MESH Headings
- Amygdala/metabolism
- Animals
- Central Nervous System/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
- Hypothalamus/metabolism
- Male
- Olfactory Pathways/metabolism
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Galanin/metabolism
- Spinal Cord/metabolism
- Sulfur Radioisotopes
- Trigeminal Nucleus, Spinal/metabolism
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Affiliation(s)
- G Barreda-Gómez
- Department of Pharmacology, Faculty of Medicine and Odontology, University of Basque Country, E-48940-Leioa, Vizcaya, Spain
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46
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Lu X, Mazarati A, Sanna P, Shinmei S, Bartfai T. Distribution and differential regulation of galanin receptor subtypes in rat brain: effects of seizure activity. Neuropeptides 2005; 39:147-52. [PMID: 15944003 DOI: 10.1016/j.npep.2004.12.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Accepted: 12/02/2004] [Indexed: 11/18/2022]
Abstract
Galanin, acting at the GalR1-3 subtypes of galanin receptors, is involved in the regulation of cognition, mood, feeding, seizure activity and pain. The understanding of galanin's effects in molecular and cellular terms has been hampered by the lack of receptor subtype selective ligands and antibodies. Previous in situ hybridization data showed that GalR1 and GalR2 receptors are abundant in the rat brain, while the distribution of GalR3 is contradictory and most studies demonstrated a low expression levels in the rat brain. The distribution of galanin receptor subtypes at protein level is unknown. In the present study, we report the regional distribution of the galanin receptors: GalR1 and non-GalR1 receptors, using a recently synthesized high affinity GalR2/3 selective ligand, galanin (2-11), and galanin (1-29), as competitors, in saturating (125)I-galanin membrane binding assay. We show that paraventricular nucleus (PVN) express predominantly GalR1, whereas areas like the dorsal raphe nucleus (DRN), hippocampus and amygdala express both the GalR1 and non-GalR1 receptors. We speculate that the GalR2/3 binding sites detected by galanin (2-11) binding in our study probably represent mostly GalR2 receptors. In addition, we show regionally specific and subtype specific regulation of galanin receptors. Status epilepticus (SE), known to deplete galanin from axonal projections of locus coeruleus and septum/diagonal band neurons in the hippocampus and to induce galanin expression in a subset of hippocampal cells, down regulates GalR2 receptor mRNA and proteins by 30% without altering the GalR1 receptors.
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MESH Headings
- Amygdala/physiology
- Animals
- Brain/physiology
- CHO Cells
- Cricetinae
- Down-Regulation
- Galanin/metabolism
- Galanin/pharmacology
- Gene Expression
- Hippocampus/physiology
- Ligands
- Male
- Muscarinic Agonists
- Paraventricular Hypothalamic Nucleus/physiology
- Peptide Fragments/metabolism
- Peptide Fragments/pharmacology
- Pilocarpine
- Raphe Nuclei/physiology
- Rats
- Rats, Sprague-Dawley
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Receptors, Galanin/genetics
- Receptors, Galanin/metabolism
- Status Epilepticus/chemically induced
- Status Epilepticus/physiopathology
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Affiliation(s)
- Xiaoying Lu
- Department of Neuropharmacology, The Harold L. Dorris Neurological Research Center, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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47
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Abstract
Galanin(2-11) has been introduced as a receptor subtype selective ligand for the GalR2 subtype of the galanin receptors, and has gained use in pharmacological studies of galaninergic signaling in the past two years. By introducing l-Ala substitutions in the galanin(2-11) sequence, we have examined the amino acid residues which are of importance for binding to the GalR2 receptor. Our study shows that Trp2, Asn5, Gly8 and Tyr9 are of great importance for high affinity binding. When placed in an alpha-helical conformation, the side chains of these residues are, with the exception of Tyr9, displayed on the same "side" of the peptide. This information is useful in the rational design of non-peptide type GalR2 receptor ligands.
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Affiliation(s)
- Linda Lundström
- Department of Neurochemistry and Neurotoxicology, Stockholm University, Svante Arrheniusv. 21A, 106 91 Stockholm, Sweden.
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48
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Xia S, Kjaer S, Zheng K, Hu PS, Xu T, Hökfelt T, Xu ZQD. Constitutive and ligand-induced internalization of EGFP-tagged galanin R2 and Rl receptors in PC12 cells. Neuropeptides 2005; 39:173-8. [PMID: 15885774 DOI: 10.1016/j.npep.2005.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Accepted: 02/03/2005] [Indexed: 11/25/2022]
Abstract
In the present experiments trafficking of the galanin R1-(GALR1) and, in particular, the galanin R2 receptor (GALR2) was studied after fusion with enhanced green fluorescent protein (GALR1-EGFP and GALR2-EGFP) and transfection into PC12 cells. Both fusion proteins were predominantly localized on the plasma membrane and internalized in a dose dependent manner after incubation with galanin. Preincubation with M35 or M40 did not prevent galanin-induced internalization of GALR1-EGFP or GALR2-EGFP. However, AR-M1896, a selective GALR2 agonist, caused GALR2, but not GALR1 internalization. Hyperosmotic sucrose inhibited internalization of GALR2-EGFP. After co-incubation with galanin, GALR2-EGFP was co-localized with internalized Texas Red transferrin, a marker of the clathrin endocytic pathway. Experiments with protein synthesis inhibition and Texas Red transferrin suggest that GALR2 is constitutively internalized. Studies in progress will show if this is the case also for GALR1.
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MESH Headings
- Animals
- Bradykinin/analogs & derivatives
- Bradykinin/pharmacology
- Calcium Signaling/physiology
- Endocytosis/physiology
- Fluorescent Dyes/pharmacology
- Galanin/pharmacology
- Green Fluorescent Proteins/genetics
- Ligands
- Neurons/metabolism
- PC12 Cells
- Peptide Fragments/pharmacology
- Protein Transport/physiology
- Rats
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Transfection
- Xanthenes/pharmacology
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Affiliation(s)
- Sheng Xia
- Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden
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49
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Abstract
The distribution of immunoreactivity for the three identified neuropeptide galanin receptors, GalR1, GalR2, and GalR3, was determined in areas of the mouse brain involved in drug addiction, including the ventral tegmental area (VTA), substantia nigra (SN), nucleus accumbens (NA), and locus coeruleus (LC). All three galanin receptors are found in the VTA, SN, NA, and LC; however, GalR1 protein is most highly represented in the VTA, NA, and SN, suggesting that GalR1 may play a predominant role in galanin-mediated regulation of dopamine neurotransmission. GalR1 and GalR3 protein levels are high in the LC, suggesting that these isoforms may be important for galanin-mediated regulation of noradrenergic transmission during opiate withdrawal. Although the distribution of GalR1, GalR2, and GalR3 largely recapitulates the pattern of galanin binding throughout the brain, some discrepancies exist, suggesting that another galanin receptor(s) may be present in some brain areas. Overall, GalR1, GalR2, and GalR3 are distributed widely throughout the brain, correlate with widespread galanin binding, and colocalize with tyrosine hydroxylase in catecholaminergic brain areas.
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Affiliation(s)
- Jessica J Hawes
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06508, USA
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50
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Henson BS, Neubig RR, Jang I, Ogawa T, Zhang Z, Carey TE, D'Silva NJ. Galanin receptor 1 has anti-proliferative effects in oral squamous cell carcinoma. J Biol Chem 2005; 280:22564-71. [PMID: 15767248 DOI: 10.1074/jbc.m414589200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In the United States, oral cancer accounts for more deaths annually than cervical cancer, leukemias, or Hodgkin's lymphoma. Studies have shown that aberrations of chromosome 18q develop with tumor progression and are associated with significantly decreased survival in head and neck cancer patients. The G-protein-coupled receptor, galanin receptor 1 (GALR1), maps to this region of chromosome 18q. Although the role of GALR1 has been well characterized in neuronal cells, little is known regarding this receptor in non-neuronal cells. In this study, the expression, mitogenic function, and signaling mechanism of GALR1 are investigated in normal and malignant oral epithelial cells. mRNA expression was determined via reverse transcriptase-PCR. Protein quantification was done via immunoblot analysis and enzyme-linked immunosorbent assay. For functional and signaling studies, an inhibitory antibody was generated to the N-terminal ligand binding domain of GALR1. GALR1 protein and mRNA expression and GAL secretion were detected at variable levels in immortalized human oral keratinocytes and human oropharyngeal squamous cell carcinoma cell lines. Upon competitive inhibition of GALR1, proliferation was up-regulated in immortalized and malignant keratinocytes. Furthermore, studies with the inhibitory antibody and U0126, the MAPK inhibitor, show that GALR1 inhibits proliferation in immortalized and malignant keratinocytes by inactivating the MAPK pathway. GALR1s inhibitory effects on proliferation in epithelial cells raises the possibility that inactivation or disregulation of this receptor can lead to uncontrolled proliferation and neoplastic transformation.
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MESH Headings
- Animals
- Antibodies/chemistry
- Antineoplastic Agents/pharmacology
- Binding, Competitive
- Butadienes/pharmacology
- CHO Cells
- Carcinoma, Squamous Cell/drug therapy
- Carcinoma, Squamous Cell/pathology
- Cell Proliferation/drug effects
- Cell Transformation, Neoplastic
- Cells, Cultured
- Chromosomes, Human, Pair 18
- Cricetinae
- Culture Media, Conditioned/pharmacology
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Enzyme-Linked Immunosorbent Assay
- Galanin/chemistry
- Humans
- Immunoblotting
- Keratinocytes/cytology
- Keratinocytes/metabolism
- Ligands
- MAP Kinase Signaling System
- Models, Biological
- Mouth Neoplasms/drug therapy
- Nitriles/pharmacology
- Protein Binding
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/chemistry
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/metabolism
- Receptor, Galanin, Type 3/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Time Factors
- Transfection
- Up-Regulation
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Affiliation(s)
- Bradley S Henson
- Department of Oral Medicine, Pathology, and Oncology, University of Michigan School of Dentistry, Ann Arbor, 48109-0506, USA
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