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Boal F, Cinato M, Timotin A, Münzberg H, Qualls-Creekmore E, Kramar S, Loi H, Roncalli J, Keita S, Tronchere H, Kunduzova O. Galanin Regulates Myocardial Mitochondrial ROS Homeostasis and Hypertrophic Remodeling Through GalR2. Front Pharmacol 2022; 13:869179. [PMID: 35431947 PMCID: PMC9011366 DOI: 10.3389/fphar.2022.869179] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/01/2022] [Indexed: 11/25/2022] Open
Abstract
The regulatory peptide galanin is broadly distributed in the central nervous systems and peripheral tissues where it modulates numerous physiological and pathological processes through binding to its three G-protein-coupled receptors, GalR1-3. However, the function and identity of the galaninergic system in the heart remain unclear. Therefore, we investigated the expression of the galanin receptors in cardiac cells and tissues and found that GalR2 is the dominant receptor subtype in adult mouse hearts, cardiomyocytes and H9C2 cardiomyoblasts. In vivo, genetic suppression of GalR2 promotes cardiac hypertrophy, fibrosis and mitochondrial oxidative stress in the heart. In vitro, GalR2 silencing by siRNA abolished the beneficial effects of galanin on cell hypertrophy and mitochondrial reactive oxygen species (ROS) production. These findings unravel new insights into the role of galaninergic system in the heart and suggest novel therapeutic strategies in heart disease.
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Affiliation(s)
- Frederic Boal
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Mathieu Cinato
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Andrei Timotin
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Heike Münzberg
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, CA, United States
| | - Emily Qualls-Creekmore
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, CA, United States
| | - Solomiia Kramar
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Halyna Loi
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Jerome Roncalli
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France.,Department of Cardiology, Toulouse University Hospital, Toulouse, France
| | - Sokhna Keita
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Helene Tronchere
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
| | - Oksana Kunduzova
- National Institute of Health and Medical Research (INSERM) U1297, Toulouse, France.,Paul Sabatier University, Toulouse, France
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Mohd Zahir I, Ogawa S, Dominic NA, Soga T, Parhar IS. Spexin and Galanin in Metabolic Functions and Social Behaviors With a Focus on Non-Mammalian Vertebrates. Front Endocrinol (Lausanne) 2022; 13:882772. [PMID: 35692389 PMCID: PMC9174643 DOI: 10.3389/fendo.2022.882772] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/19/2022] [Indexed: 01/31/2023] Open
Abstract
Spexin (SPX) and galanin (GAL) are two neuropeptides that are phylogenetically related and have descended from a common ancestral gene. Considerable attention has been given to these two multifunctional neuropeptides because they share GAL receptors 1,2, and 3. Since GAL and SPX-synthesizing neurons have been detected in several brain areas, therefore, it can be speculated that SPX and GAL are involved in various neurophysiological functions. Several studies have shown the functions of these two neuropeptides in energy regulation, reproduction, and response to stress. SPX acts as a satiety factor to suppress food intake, while GAL has the opposite effect as an orexigenic factor. There is evidence that SPX acts as an inhibitor of reproductive functions by suppressing gonadotropin release, while GAL modulates the activity of gonadotropin-releasing hormone (GnRH) neurons in the brain and gonadotropic cells in the pituitary. SPX and GAL are responsive to stress. Furthermore, SPX can act as an anxiolytic factor, while GAL exerts anti-depressant and pro-depressive effects depending on the receptor it binds. This review describes evidence supporting the central roles of SPX and GAL neuropeptides in energy balance, reproduction, stress, and social behaviors, with a particular focus on non-mammalian vertebrate systems.
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Affiliation(s)
- Izzati Mohd Zahir
- Brain Research Institute Monash Sunway, School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
| | - Satoshi Ogawa
- Brain Research Institute Monash Sunway, School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
| | | | - Tomoko Soga
- Brain Research Institute Monash Sunway, School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
| | - Ishwar S. Parhar
- Brain Research Institute Monash Sunway, School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
- *Correspondence: Ishwar S. Parhar,
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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] [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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Neuropeptidergic Control of Feeding: Focus on the Galanin Family of Peptides. Int J Mol Sci 2021; 22:ijms22052544. [PMID: 33802616 PMCID: PMC7961366 DOI: 10.3390/ijms22052544] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 02/24/2021] [Accepted: 02/27/2021] [Indexed: 12/16/2022] Open
Abstract
Obesity/overweight are important health problems due to metabolic complications. Dysregulation of peptides exerting orexigenic/anorexigenic effects must be investigated in-depth to understand the mechanisms involved in feeding behaviour. One of the most important and studied orexigenic peptides is galanin (GAL). The aim of this review is to update the mechanisms of action and physiological roles played by the GAL family of peptides (GAL, GAL-like peptide, GAL message-associated peptide, alarin) in the control of food intake and to review the involvement of these peptides in metabolic diseases and food intake disorders in experimental animal models and humans. The interaction between GAL and NPY in feeding and energy metabolism, the relationships between GAL and other substances involved in food intake mechanisms, the potential pharmacological strategies to treat food intake disorders and obesity and the possible clinical applications will be mentioned and discussed. Some research lines are suggested to be developed in the future, such as studies focused on GAL receptor/neuropeptide Y Y1 receptor interactions in hypothalamic and extra-hypothalamic nuclei and sexual differences regarding the expression of GAL in feeding behaviour. It is also important to study the possible GAL resistance in obese individuals to better understand the molecular mechanisms by which GAL regulates insulin/glucose metabolism. GAL does not exert a pivotal role in weight regulation and food intake, but this role is crucial in fat intake and also exerts an important action by regulating the activity of other key compounds under conditions of stress/altered diet.
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Guo L, He B, Fang P, Bo P, Zhang Z. Activation of central galanin receptor 2 mitigated insulin resistance in adipocytes of diabetic rats. J Endocrinol Invest 2021; 44:515-522. [PMID: 32588381 DOI: 10.1007/s40618-020-01336-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/12/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE Our and other's studies showed that administration of neuropeptide galanin may mitigate insulin resistance via promoting glucose transporter 4 (GLUT4) expression and translocation in rats. The objective of this study is to investigate whether galanin receptor 2 (GAL2-R) in brain mediates the ameliorative effect of galanin on insulin resistance in adipose tissues of type 2 diabetic rats. METHODS In this study galanin, GAL2-R agonist M1145 and GAL2-R antagonist M871 were respectively or cooperatively injected into intracerebroventricles of type 2 diabetic rats once a day for successive fifteen days. Then the plasma and fat tissues of rats were used to estimate the alterations of insulin resistance indexes. RESULTS The central administration of galanin enhanced 2-deoxy-[3H]-D-glucose, peroxisome proliferator-activated receptor γ and adiponectin levels, food intake and body weight, GLUT4 mRNA expression and GLUT4 concentration in plasma membranes, as well as homeostasis model assessment-insulin resistance index. Those effects of galanin may be blocked by M817, and imitated by M1145 except for food intake and body weight. CONCLUSION Those results suggest that central GAL2-R mediates the beneficial effects of galanin on insulin sensitivity in type 2 diabetic rats. GAL2-R agonist may be taken as a potential antidiabetic agent to treat insulin resistance and type 2 diabetes.
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Affiliation(s)
- L Guo
- Department of Physical Education, Chuzhou College, Chuzhou, 239012, Anhui, China
| | - B He
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Nantong Street #98, Yangzhou, 225001, China
| | - P Fang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Nantong Street #98, Yangzhou, 225001, China
| | - P Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Nantong Street #98, Yangzhou, 225001, China
| | - Z Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Nantong Street #98, Yangzhou, 225001, China.
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Mills EG, Izzi-Engbeaya C, Abbara A, Comninos AN, Dhillo WS. Functions of galanin, spexin and kisspeptin in metabolism, mood and behaviour. Nat Rev Endocrinol 2021; 17:97-113. [PMID: 33273729 DOI: 10.1038/s41574-020-00438-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
The bioactive peptides galanin, spexin and kisspeptin have a common ancestral origin and their pathophysiological roles are increasingly the subject of investigation. Evidence suggests that these bioactive peptides play a role in the regulation of metabolism, pancreatic β-cell function, energy homeostasis, mood and behaviour in several species, including zebrafish, rodents and humans. Galanin signalling suppresses insulin secretion in animal models (but not in humans), is potently obesogenic and plays putative roles governing certain evolutionary behaviours and mood modulation. Spexin decreases insulin secretion and has potent anorectic, analgesic, anxiolytic and antidepressive-like effects in animal models. Kisspeptin modulates glucose-stimulated insulin secretion, food intake and/or energy expenditure in animal models and humans. Furthermore, kisspeptin is implicated in the control of reproductive behaviour in animals, modulation of human sexual and emotional brain processing, and has antidepressive and fear-suppressing effects. In addition, galanin-like peptide is a further member of the galaninergic family that plays emerging key roles in metabolism and behaviour. Therapeutic interventions targeting galanin, spexin and/or kisspeptin signalling pathways could therefore contribute to the treatment of conditions ranging from obesity to mood disorders. However, many gaps and controversies exist, which must be addressed before the therapeutic potential of these bioactive peptides can be established.
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Affiliation(s)
- Edouard G Mills
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - Chioma Izzi-Engbeaya
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Ali Abbara
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Alexander N Comninos
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Waljit S Dhillo
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK.
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK.
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7
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Genders SG, Scheller KJ, Djouma E. Neuropeptide modulation of addiction: Focus on galanin. Neurosci Biobehav Rev 2020; 110:133-149. [DOI: 10.1016/j.neubiorev.2018.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
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Leidmaa E, Gazea M, Patchev AV, Pissioti A, Christian Gassen N, Kimura M, Liposits Z, Kallo I, Almeida OFX. Blunted leptin sensitivity during hedonic overeating can be reinstated by activating galanin 2 receptors (Gal2R) in the lateral hypothalamus. Acta Physiol (Oxf) 2020; 228:e13345. [PMID: 31310704 DOI: 10.1111/apha.13345] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022]
Abstract
AIM Since foods with high hedonic value are often consumed in excess of energetic needs, this study was designed to identify the mechanisms that may counter anorexigenic signalling in the presence of hedonic foods in lean animals. METHODS Mice, in different states of satiety (fed/fasted, or fed/fasted and treated with ghrelin or leptin, respectively), were allowed to choose between high-fat/high-sucrose and standard foods. Intake of each food type and the activity of hypothalamic neuropetidergic neurons that regulate appetite were monitored. In some cases, food choice was monitored in leptin-injected fasted mice that received microinjections of galanin receptor agonists into the lateral hypothalamus. RESULTS Appetite-stimulating orexin neurons in the lateral hypothalamus are rapidly activated when lean, satiated mice consume a highly palatable food (PF); such activation (upregulated c-Fos expression) occurred even after administration of the anorexigenic hormone leptin and despite intact leptin signalling in the hypothalamus. The ability of leptin to restrain PF eating is restored when a galanin receptor 2 (Gal2R) agonist is injected into the lateral hypothalamus. CONCLUSION Hedonically-loaded foods interrupt the inhibitory actions of leptin on orexin neurons and interfere with the homeostatic control of feeding. Overeating of palatable foods can be curtailed in lean animals by activating Gal2R in the lateral hypothalamus.
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Affiliation(s)
- Este Leidmaa
- Max Planck Institute of Psychiatry Munich Germany
- Graduate School of Systems Neuroscience Munich University Planegg‐Martinsried Germany
- Institute of Molecular Psychiatry Bonn Germany
| | - Mary Gazea
- Max Planck Institute of Psychiatry Munich Germany
| | | | | | | | | | - Zsolt Liposits
- Institute of Experimental Medicine Hungarian Academy of Sciences Budapest Hungary
| | - Imre Kallo
- Institute of Experimental Medicine Hungarian Academy of Sciences Budapest Hungary
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Fang P, He B, Yu M, Shi M, Zhu Y, Zhang Z, Bo P. Central galanin receptor 2 mediates galanin action to promote systemic glucose metabolism of type 2 diabetic rats. Biochem Pharmacol 2018; 156:241-247. [PMID: 30170096 DOI: 10.1016/j.bcp.2018.08.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/22/2018] [Indexed: 12/22/2022]
Abstract
Although recent results of our and other studies have showed that galanin (GAL) is an antidiabetic and anti-inflammatory neuropeptide, the molecular mechanism how central GAL regulates energy homeostasis and insulin sensitivity is still not fully understood. The aim of this study was to investigate whether central type 2 of GAL receptors (GALR2) are involved in the regulation of systemic glucose metabolism and its underlying mechanisms. In the present study, type 2 diabetic rats were intracerebroventricularly (i.c.v.) given 100 nM/kg/d GALR2 agonist M1145 or GALR2 antagonist M871 in 5 μl artificial cerebrospinal fluid once a day for consecutive 21 days. Then insulin resistance indexes, inflammatory factor and many genes associated with the function of glucose metabolism were examined in peripheral tissues. The present findings showed that the intracerebroventricular injection of M1145 or M871 respectively increased or decreased glucose infusion rates in hyperinsulinemic euglycemic clamp tests, but attenuated or enhanced the plasma inflammatory factors and glucose concentration in type 2 diabetic rats. Moreover, administration of M1145 markedly increased PGC-1α and GLUT4 expression in skeletal muscles and adipocytes of type 2 diabetic rats. In conclusion, activation of central GALR2 promotes glucose metabolism and ameliorates insulin resistance mainly through the PGC-1α/GLUT4 pathways. The central GALR2 is crucial to whole-body insulin sensitivity and energy homeostasis.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou 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
| | - Biao He
- College of Physical Education, Anhui Normal University, Wuhu 241003, China
| | - Mei Yu
- Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou 225300, 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 225001, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China.
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 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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10
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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] [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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11
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Timotin A, Pisarenko O, Sidorova M, Studneva I, Shulzhenko V, Palkeeva M, Serebryakova L, Molokoedov A, Veselova O, Cinato M, Tronchere H, Boal F, Kunduzova O. Myocardial protection from ischemia/reperfusion injury by exogenous galanin fragment. Oncotarget 2017; 8:21241-21252. [PMID: 28177906 PMCID: PMC5400580 DOI: 10.18632/oncotarget.15071] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/09/2017] [Indexed: 12/20/2022] Open
Abstract
Background and purpose Galanin is a multifunctional neuropeptide with pleiotropic roles. The present study was designed to evaluate the potential effects of galanin (2-11) (G1) on functional and metabolic abnormalities in response to myocardial ischemia-reperfusion (I/R) injury. Experimental approach Peptide G1 was synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase method. The chemical structure was identified by 1H-NMR spectroscopy and mass spectrometry. Experiments were conducted using a rat model of I/R injury in vivo, isolated perfused rat hearts ex vivo and cultured rat cardiomyoblast H9C2 cells in vitro. Cardiac function, infarct size, myocardial energy metabolism, hemodynamic parameters, plasma levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) were measured in order to evaluate the effects of G1 on myocardial I/R injury. Key results Treatment with G1 increased cell viability in a dose-dependent manner, inhibited cell apoptosis and excessive mitochondrial reactive oxygen species (ROS) production in response to oxidative stress in H9C2 cells. Pre- or postischemic infusion of G1 enhanced functional and metabolic recovery during reperfusion of the ischemic isolated rat heart. Administration of G1 at the onset of reperfusion significantly reduced infarct size and plasma levels of CK-MB and LDH in rats subjected to myocardial I/R injury. Conclusions and implications These data provide the first evidence for cardioprotective activity of galanin G1 against myocardial I/R injury. Therefore, peptide G1 may represent a promising treatment strategy for ischemic heart disease.
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Affiliation(s)
- Andrei Timotin
- National Institute of Health and Medical Research (INSERM), Toulouse, France.,University of Toulouse, UPS, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Oleg Pisarenko
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Maria Sidorova
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Irina Studneva
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Valentin Shulzhenko
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Marina Palkeeva
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Larisa Serebryakova
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Aleksander Molokoedov
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Oksana Veselova
- Russian Cardiology Research-and-Production Complex, Moscow, Russian Federation, Russia
| | - Mathieu Cinato
- National Institute of Health and Medical Research (INSERM), Toulouse, France.,University of Toulouse, UPS, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Helene Tronchere
- National Institute of Health and Medical Research (INSERM), Toulouse, France.,University of Toulouse, UPS, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Frederic Boal
- National Institute of Health and Medical Research (INSERM), Toulouse, France.,University of Toulouse, UPS, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Oksana Kunduzova
- National Institute of Health and Medical Research (INSERM), Toulouse, France.,University of Toulouse, UPS, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
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12
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The galanin-3 receptor antagonist, SNAP 37889, suppresses alcohol drinking and morphine self-administration in mice. Neuropharmacology 2017; 118:1-12. [DOI: 10.1016/j.neuropharm.2017.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/17/2017] [Accepted: 03/02/2017] [Indexed: 02/07/2023]
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13
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Fang P, Yu M, He B, Guo L, Huang X, Kong G, Shi M, Zhu Y, Bo P, Zhang Z. Central injection of GALR1 agonist M617 attenuates diabetic rat skeletal muscle insulin resistance through the Akt/AS160/GLUT4 pathway. Mech Ageing Dev 2017; 162:122-128. [DOI: 10.1016/j.mad.2016.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 03/17/2016] [Accepted: 03/31/2016] [Indexed: 12/27/2022]
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14
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Webling K, Runesson J, Lang A, Saar I, Kofler B, Langel Ü. Ala 5-galanin (2-11) is a GAL 2R specific galanin analogue. Neuropeptides 2016; 60:75-82. [PMID: 27592409 DOI: 10.1016/j.npep.2016.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 12/18/2022]
Abstract
It is over 30years since the regulatory peptide galanin was discovered by Professor Mutt and co-workers. Galanin exerts its effects by binding to three galanin G-protein coupled receptors, namely GAL1R, GAL2R and GAL3R. Each galanin receptor has a different distribution in the central nervous system and the peripheral nervous system as well as distinctive signaling pathways, which implicates that the receptors are involved in different biological- and pathological effects. The delineation of the galaninergic system is however difficult due to a lack of stable, specific galanin receptor ligands. Herein, a new short GAL2R specific ligand, Ala5-galanin (2-11), is presented. The galanin (2-11) modified analogue Ala5-galanin (2-11) was tested in 125I-galanin competitive binding studies for the three galanin receptors and the G-protein coupled receptor signaling properties was tested by the ability to influence second-messenger molecules like inositol phosphate and cyclic adenosine monophosphate. In addition, two different label-free real-time assays, namely EnSpire® based on an optical biosensor and xCELLigence® based on an electric biosensor, were used for evaluating the signaling properties using cell lines with different levels of receptor expression. Ala5-galanin (2-11) was subsequently found to be a full agonist for GAL2R with more than 375-fold preference for GAL2R compared to both GAL1R and GAL3R. The single amino acid substitution of serine to alanine at position 5 in the short ligand galanin (2-11) resulted in a ligand subsequently unable to bind neither GAL3R nor GAL1R, even at concentrations as high as 0.1mM.
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Affiliation(s)
- Kristin Webling
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden.
| | - Johan Runesson
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden
| | - Andreas Lang
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Indrek Saar
- Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Barbara Kofler
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Ülo Langel
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden; Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
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15
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Mikulášková B, Maletínská L, Zicha J, Kuneš J. The role of food intake regulating peptides in cardiovascular regulation. Mol Cell Endocrinol 2016; 436:78-92. [PMID: 27450151 DOI: 10.1016/j.mce.2016.07.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/07/2016] [Accepted: 07/19/2016] [Indexed: 12/11/2022]
Abstract
Obesity is a risk factor that worsens cardiovascular events leading to higher morbidity and mortality. However, the exact mechanisms of relation between obesity and cardiovascular events are unclear. Nevertheless, it has been demonstrated that pharmacological therapy for obesity has great potential to improve some cardiovascular problems. Therefore, it is important to determine the common mechanisms regulating both food intake and blood pressure. Several hormones produced by peripheral tissues work together with neuropeptides involved in the regulation of both food intake and blood pressure. Anorexigenic (food intake lowering) hormones such as leptin, glucagon-like peptide-1 and cholecystokinin cooperate with α-melanocyte-stimulating hormone, cocaine- and amphetamine-regulated peptide as well as prolactin-releasing peptide. Curiously their collective actions result in increased sympathetic activity, especially in the kidney, which could be one of the factors responsible for the blood pressure increases seen in obesity. On the other hand, orexigenic (food intake enhancing) peptides, especially ghrelin released from the stomach and acting in the brain, cooperates with orexins, neuropeptide Y, melanin-concentrating hormone and galanin, which leads to decreased sympathetic activity and blood pressure. This paradox should be intensively studied in the future. Moreover, it is important to know that the hypothalamus together with the brainstem seem to be major structures in the regulation of food intake and blood pressure. Thus, the above mentioned regions might be essential brain components in the transmission of peripheral signals to the central effects. In this short review, we summarize the current information on cardiovascular effects of food intake regulating peptides.
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Affiliation(s)
- B Mikulášková
- Institute of Physiology AS CR, Prague, Czech Republic; Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
| | - L Maletínská
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
| | - J Zicha
- Institute of Physiology AS CR, Prague, Czech Republic
| | - J Kuneš
- Institute of Physiology AS CR, Prague, Czech Republic; Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
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16
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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] [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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17
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Bu L, Chang X, Cheng X, Yao Q, Su B, Sheng C, Qu S. Activated central galanin type 1 receptor alleviated insulin resistance in diabetic rat muscle. J Neurosci Res 2016; 94:947-55. [PMID: 27410235 DOI: 10.1002/jnr.23775] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Le Bu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Xusheng Chang
- Department of General Surgery; Yancheng City First People's Hospital; Yancheng City Jiangsu People's Republic of China
| | - Xiaoyun Cheng
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Qian Yao
- Key Laboratory of Sichuan Province of Medicinal Chemistry; Chengdu University; Chengdu People's Republic of China
| | - Bin Su
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Chunjun Sheng
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Shen Qu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
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18
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Reyes-Alcaraz A, Lee YN, Son GH, Kim NH, Kim DK, Yun S, Kim DH, Hwang JI, Seong JY. Development of Spexin-based Human Galanin Receptor Type II-Specific Agonists with Increased Stability in Serum and Anxiolytic Effect in Mice. Sci Rep 2016; 6:21453. [PMID: 26907960 PMCID: PMC4764904 DOI: 10.1038/srep21453] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/22/2016] [Indexed: 01/16/2023] Open
Abstract
The novel neuropeptide spexin (SPX) was discovered to activate galanin receptor 2 (GALR2) and 3 (GALR3) but not galanin receptor 1 (GALR1). Although GALR2 is known to display a function, particularly in anxiety, depression, and appetite regulation, the further determination of its function would benefit from a more stable and selective agonist that acts only at GALR2. In the present study, we developed a GALR2-specific agonist with increased stability in serum. As galanin (GAL) showed a low affinity to GALR3, the residues in SPX were replaced with those in GAL, revealing that particular mutations such as Gln5 → Asn, Met7 → Ala, Lys11 → Phe, and Ala13 → Pro significantly decreased potencies toward GALR3 but not toward GALR2. Quadruple (Qu) mutation of these residues still retained potency to GALR2 but totally abolished the potency to both GALR3 and GALR1. The first amino acid modifications or D-Asn1 substitution significantly increased the stability when they are incubated in 100% fetal bovine serum. Intracerebroventricular administration of the mutant peptide with D-Asn1 and quadruple substitution (dN1-Qu) exhibited an anxiolytic effect in mice. Taken together, the GALR2-specific agonist with increased stability can greatly help delineation of GALR2-mediated functions and be very useful for treatments of anxiety disorder.
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Affiliation(s)
| | - Yoo-Na Lee
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Gi Hoon Son
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Nam Hoon Kim
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Dong-Kyu Kim
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Seongsik Yun
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Dong-Hoon Kim
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Jong-Ik Hwang
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Jae Young Seong
- Graduate School of Medicine, Korea University, Seoul 02841, Republic of Korea
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19
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Zhang Z, Fang P, He B, Guo L, Runesson J, Langel Ü, Shi M, Zhu Y, Bo P. Central Administration of Galanin Receptor 1 Agonist Boosted Insulin Sensitivity in Adipose Cells of Diabetic Rats. J Diabetes Res 2016; 2016:9095648. [PMID: 27127795 PMCID: PMC4835658 DOI: 10.1155/2016/9095648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 01/18/2023] Open
Abstract
Our previous studies testified the beneficial effect of central galanin on insulin sensitivity of type 2 diabetic rats. The aim of the study was further to investigate whether central M617, a galanin receptor 1 agonist, can benefit insulin sensitivity. The effects of intracerebroventricular administration of M617 on insulin sensitivity and insulin signaling were evaluated in adipose tissues of type 2 diabetic rats. The results showed that central injection of M617 significantly increased plasma adiponectin contents, glucose infusion rates in hyperinsulinemic-euglycemic clamp tests, GLUT4 mRNA expression levels, GLUT4 contents in plasma membranes, and total cell membranes of the adipose cells but reduced the plasma C-reactive protein concentration in nondiabetic and diabetic rats. The ratios of GLUT4 contents were higher in plasma membranes to total cell membranes in both nondiabetic and diabetic M617 groups than each control. In addition, the central administration of M617 enhanced the ratios of pAkt/Akt and pAS160/AS160, but not phosphorylative cAMP response element-binding protein (pCREB)/CREB in the adipose cells of nondiabetic and diabetic rats. These results suggest that excitation of central galanin receptor 1 facilitates insulin sensitivity via activation of the Akt/AS160 signaling pathway in the fat cells of type 2 diabetic rats.
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MESH Headings
- Adipocytes/drug effects
- Adipocytes/metabolism
- Adiponectin/blood
- Animals
- Biomarkers/blood
- Bradykinin/administration & dosage
- Bradykinin/analogs & derivatives
- C-Reactive Protein/analysis
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/genetics
- Disease Models, Animal
- GTPase-Activating Proteins/metabolism
- Galanin/administration & dosage
- Glucose Transporter Type 4/genetics
- Glucose Transporter Type 4/metabolism
- Hypoglycemic Agents/pharmacology
- Injections, Intraventricular
- Insulin/pharmacology
- Insulin Resistance
- Male
- Peptide Fragments/administration & dosage
- Phosphorylation
- Proto-Oncogene Proteins c-akt/metabolism
- Rats, Wistar
- Receptor, Galanin, Type 1/agonists
- Receptor, Galanin, Type 1/metabolism
- Signal Transduction/drug effects
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Affiliation(s)
- Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Penghua Fang
- Department of Physiology, School of Hanlin, Nanjing University of Chinese Medicine, Taizhou, Jiangsu 225300, China
- Key Laboratory of Gerontology, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Biao He
- Key Laboratory of Gerontology, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Lili Guo
- Key Laboratory of Gerontology, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Johan Runesson
- Department of Neurochemistry, Arrhenius Laboratories for Natural Sciences Stockholm University, 10691 Stockholm, Sweden
| | - Ülo Langel
- Department of Neurochemistry, Arrhenius Laboratories for Natural Sciences Stockholm University, 10691 Stockholm, Sweden
| | - Mingyi Shi
- Key Laboratory of Gerontology, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Yan Zhu
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
- *Yan Zhu: and
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
- Key Laboratory of Gerontology, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
- *Ping Bo:
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20
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Type 2 diabetes mellitus as a disorder of galanin resistance. Exp Gerontol 2015; 73:72-7. [PMID: 26585047 DOI: 10.1016/j.exger.2015.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 11/10/2015] [Accepted: 11/12/2015] [Indexed: 12/16/2022]
Abstract
The increasing prevalence of type 2 diabetes mellitus with its high morbidity and mortality becomes an important health problem. The multifactorial etiology of type 2 diabetes mellitus is relative to many gene and molecule alterations, and increased insulin resistance. Besides these, however, there are still other predisposing and risk factors accounting for type 2 diabetes mellitus not to be identified and recognized. Emerging evidence indicated that defects in galanin function played a crucial role in development of type 2 diabetes mellitus. Galanin homeostasis is tightly relative to insulin resistance and is regulated by blood glucose. Hyperglycemia, hyperinsulinism, enhanced plasma galanin levels and decreased galanin receptor activities are some of the characters of type 2 diabetes mellitus. The discrepancy between high insulin level and low glucose handling is named as insulin resistance. Similarly, the discrepancy between high galanin level and low glucose handling may be denominated as galanin resistance too. In this review, the characteristic milestones of type 2 diabetes mellitus were condensed as two analogical conceptual models, obesity-hyper-insulin-insulin resistance-type 2 diabetes mellitus and obesity-hyper-galanin-galanin resistance-type 2 diabetes mellitus. Both galanin resistance and insulin resistance are correlative with each other. Conceptualizing the etiology of type 2 diabetes mellitus as a disorder of galanin resistance may inspire a new concept to deepen our knowledge about pathogenesis of type 2 diabetes mellitus, eventually leading to novel preventive and therapeutic interventions for type 2 diabetes mellitus.
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21
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Fang P, He B, Shi M, Kong G, Dong X, Zhu Y, Bo P, Zhang Z. The regulative effect of galanin family members on link of energy metabolism and reproduction. Peptides 2015; 71:240-9. [PMID: 26188174 DOI: 10.1016/j.peptides.2015.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 06/27/2015] [Accepted: 07/03/2015] [Indexed: 12/22/2022]
Abstract
It is essential for the species survival that an efficient coordination between energy storage and reproduction through endocrine regulation. The neuropeptide galanin, one of the endocrine hormones, can potently coordinate energy metabolism and the activities of hypothalamic-pituitary-gonadal reproductive axis to adjust synthesis and release of metabolic and reproductive hormones in animals and humans. However, few papers have summarized the regulative effect of the galanin family members on the link of energy storage and reproduction as yet. To address this issue, this review attempts to summarize the current information available about the regulative effect of galanin, galanin-like peptide and alarin on the metabolic and reproductive events, with special emphasis on the interactions between galanin and hypothalamic gonadotropin-releasing hormone, pituitary luteinizing hormone and ovarian hormones. This research line will further deepen our understanding of the physiological roles of the galanin family in regulating the link of energy metabolism and reproduction.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Nanjing University of Chinese Medicine Hanlin College, Taizhou 225300, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China
| | - Biao He
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China
| | - Mingyi Shi
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China
| | - Guimei Kong
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, China
| | - Xiaoyun Dong
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, China
| | - Yan Zhu
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China.
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou 225001, China; Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China.
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22
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Freimann K, Kurrikoff K, Langel Ü. Galanin receptors as a potential target for neurological disease. Expert Opin Ther Targets 2015. [PMID: 26220265 DOI: 10.1517/14728222.2015.1072513] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Galanin is a 29/30 amino acid long neuropeptide that is widely expressed in the brains of many mammals. Galanin exerts its biological activities through three different G protein-coupled receptors, GalR1, GalR2 and GalR3. The widespread distribution of galanin and its receptors in the CNS and the various physiological and pharmacological effects of galanin make the galanin receptors attractive drug targets. AREAS COVERED This review provides an overview of the role of galanin and its receptors in the CNS, the involvement of the galaninergic system in various neurological diseases and the development of new galanin receptor-specific ligands. EXPERT OPINION Recent advances and novel approaches in migrating the directions of subtype-selective ligand development and chemical modifications of the peptide backbone highlight the importance of the galanin neurochemical system as a potential target for drug development.
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Affiliation(s)
- Krista Freimann
- a 1 University of Tartu, Institute of Technology , Tartu, Estonia +372 737 4871 ;
| | - Kaido Kurrikoff
- b 2 University of Tartu, Institute of Technology , Tartu, Estonia
| | - Ülo Langel
- c 3 University of Tartu, Institute of Technology , Tartu, Estonia.,d 4 Stockholm University, Arrhenius Laboratories for Natural Science, Department of Neurochemistry , Stockholm, Sweden
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23
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Lang R, Gundlach AL, Holmes FE, Hobson SA, Wynick D, Hökfelt T, Kofler B. Physiology, signaling, and pharmacology of galanin peptides and receptors: three decades of emerging diversity. Pharmacol Rev 2015; 67:118-75. [PMID: 25428932 DOI: 10.1124/pr.112.006536] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Galanin was first identified 30 years ago as a "classic neuropeptide," with actions primarily as a modulator of neurotransmission in the brain and peripheral nervous system. Other structurally-related peptides-galanin-like peptide and alarin-with diverse biologic actions in brain and other tissues have since been identified, although, unlike galanin, their cognate receptors are currently unknown. Over the last two decades, in addition to many neuronal actions, a number of nonneuronal actions of galanin and other galanin family peptides have been described. These include actions associated with neural stem cells, nonneuronal cells in the brain such as glia, endocrine functions, effects on metabolism, energy homeostasis, and paracrine effects in bone. Substantial new data also indicate an emerging role for galanin in innate immunity, inflammation, and cancer. Galanin has been shown to regulate its numerous physiologic and pathophysiological processes through interactions with three G protein-coupled receptors, GAL1, GAL2, and GAL3, and signaling via multiple transduction pathways, including inhibition of cAMP/PKA (GAL1, GAL3) and stimulation of phospholipase C (GAL2). In this review, we emphasize the importance of novel galanin receptor-specific agonists and antagonists. Also, other approaches, including new transgenic mouse lines (such as a recently characterized GAL3 knockout mouse) represent, in combination with viral-based techniques, critical tools required to better evaluate galanin system physiology. These in turn will help identify potential targets of the galanin/galanin-receptor systems in a diverse range of human diseases, including pain, mood disorders, epilepsy, neurodegenerative conditions, diabetes, and cancer.
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Affiliation(s)
- Roland Lang
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Andrew L Gundlach
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Fiona E Holmes
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Sally A Hobson
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - David Wynick
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Tomas Hökfelt
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Barbara Kofler
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
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24
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Decaffeinated green coffee bean extract attenuates diet-induced obesity and insulin resistance in mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:718379. [PMID: 24817902 PMCID: PMC4003760 DOI: 10.1155/2014/718379] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/02/2014] [Indexed: 01/22/2023]
Abstract
This study investigated whether decaffeinated green coffee bean extract prevents obesity and improves insulin resistance and elucidated its mechanism of action. Male C57BL/6N mice (N = 48) were divided into six dietary groups: chow diet, HFD, HFD-supplemented with 0.1%, 0.3%, and 0.9% decaffeinated green coffee bean extract, and 0.15% 5-caffeoylquinic acid. Based on the reduction in HFD-induced body weight gain and increments in plasma lipids, glucose, and insulin levels, the minimum effective dose of green coffee bean extract appears to be 0.3%. Green coffee bean extract resulted in downregulation of genes involved in WNT10b- and galanin-mediated adipogenesis and TLR4-mediated proinflammatory pathway and stimulation of GLUT4 translocation to the plasma membrane in white adipose tissue. Taken together, decaffeinated green coffee bean extract appeared to reverse HFD-induced fat accumulation and insulin resistance by downregulating the genes involved in adipogenesis and inflammation in visceral adipose tissue.
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25
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Fang P, Shi M, Yu M, Guo L, Bo P, Zhang Z. Endogenous peptides as risk markers to assess the development of insulin resistance. Peptides 2014; 51:9-14. [PMID: 24184593 DOI: 10.1016/j.peptides.2013.10.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/19/2013] [Accepted: 10/21/2013] [Indexed: 01/15/2023]
Abstract
Insulin resistance, the reciprocal of insulin sensitivity, is known to be a characteristic of type 2 diabetes mellitus, and is regarded as an important mechanism in the pathogenesis. The hallmark of insulin resistance is a gradual break-down of insulin-regulative glucose uptake by muscle and adipose tissues in subjects. Insulin resistance is increasingly estimated in various disease conditions to examine and assess their etiology, pathogenesis and consequences. Although our understanding of insulin resistance has tremendously been improved in recent years, certain aspects of its estimation and etiology still remain elusive to clinicians and researchers. There are numerous factors involved in pathogenesis and mechanisms of insulin resistance. Recent studies have provided compelling clues about some peptides and proteins, including galanin, galanin-like peptide, ghrelin, adiponectin, retinol binding protein 4 (RBP4) and CRP, which may be used to simplify and to improve the determination of insulin resistance. And alterations of these peptide levels may be recognized as risk markers of developing insulin resistance and type 2 diabetes mellitus. This review examines the updated information for these peptides, highlighting the relations between these peptide levels and insulin resistance. The plasma high ghrelin, RBP4 and CRP as well as low galanin, GALP and adiponectin levels may be taken as the markers of deteriorating insulin resistance. An increase in the knowledge of these marker proteins and peptides will help us correctly diagnose and alleviate insulin resistance in clinic and study.
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Affiliation(s)
- Penghua Fang
- Research Institution of Combining Chinese Traditional and Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China; Department of Physiology, Nanjing University of Chinese Medicine Hanlin College, Taizhou, Jiangsu 225300, China
| | - Mingyi Shi
- Research Institution of Combining Chinese Traditional and Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Mei Yu
- Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu 225300, China
| | - Lili Guo
- Research Institution of Combining Chinese Traditional and Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Ping Bo
- Research Institution of Combining Chinese Traditional and Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China
| | - Zhenwen Zhang
- Research Institution of Combining Chinese Traditional and Western Medicine, Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China; Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, China.
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26
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Yu M, Fang P, Shi M, Zhu Y, Sun Y, Li Q, Bo P, Zhang Z. Galanin receptors possibly modulate the obesity-induced change in pain threshold. Peptides 2013; 44:55-9. [PMID: 23528516 DOI: 10.1016/j.peptides.2013.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 02/19/2013] [Accepted: 02/19/2013] [Indexed: 12/19/2022]
Abstract
Pain threshold may be up-regulated or down-regulated according to gender, age, race/ethnic and psychological state. Previous studies indicated that obesity may change pain threshold, both nociceptive and antinociceptive, which resulted from obesity-reduced variation of neuroendocrine. However there is a limited understanding of its molecular mechanism underlying this variation. A lot of evidence supports that galanin increases food intake and body weight to induce obesity in animals. This peptide may also modulate nociceptive susceptibility via central galanin receptor 1 and peripheral galanin receptor 2 in dorsal root ganglion. Whereas injury and obesity may up-regulate the galanin expression and stimulate its secretion to elevate the plasma levels of subjects. Pain may increase the risk of obesity through reduced physical activity. In this review, we highlighted the multiple bilateral interrelation between obesity and pain sensitivity, between galanin and obesity and between galanin and injure-induced pain. In view of the above, we reasoned that galanin receptors possibly participated in the modulation of the obesity-induced change in pain threshold, which need further direct evidence to support as yet. This review is helpful to explore the mechanism that galanin receptors regulate the obesity-induced change of pain sensitivity and to contribute to our understanding of the relation among galanin, obesity and pain threshold.
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Affiliation(s)
- Mei Yu
- Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu 225300, China
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27
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Saar I, Lahe J, Langel K, Runesson J, Webling K, Järv J, Rytkönen J, Närvänen A, Bartfai T, Kurrikoff K, Langel Ü. Novel systemically active galanin receptor 2 ligands in depression-like behavior. J Neurochem 2013; 127:114-23. [PMID: 23600864 DOI: 10.1111/jnc.12274] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/31/2013] [Accepted: 03/31/2013] [Indexed: 11/30/2022]
Abstract
Neuropeptide galanin and its three G-protein coupled receptors, galanin receptor type 1-galanin receptor type 3 (GalR1-GalR3), are involved in the regulation of numerous physiological and disease processes, and thus represent tremendous potential in neuroscience research and novel drug lead development. One of the areas where galanin is involved is depression. Previous studies have suggested that activation of GalR2 leads to attenuation of depression-like behavior. Unfortunately, lack of in vivo usable subtype specific ligands hinders testing the role of galanin in depression mechanisms. In this article, we utilize an approach of increasing in vivo usability of peptide-based ligands, acting upon CNS. Thus, we have synthesized a series of novel systemically active galanin analogs, with modest preferential binding toward GalR2. We have shown that specific chemical modifications to the galanin backbone increase brain levels upon i.v. injection of the peptides. Several of the new peptides, similar to a common clinically used antidepressant medication imipramine, exerted antidepressant-like effect in forced swim test, a mouse model of depression, at a surprisingly low dose range (< 0.5 mg/kg). We chose one of the peptides, J18, for more thorough study, and showed its efficacy also in another mouse depression model (tail suspension test), and demonstrated that its antidepressant-like effect upon i.v. administration can be blocked by i.c.v. galanin receptor antagonist M35. The effect of the J18 was also abolished in GalR2KO animals. All this suggests that systemically administered peptide analog J18 exerts its biological effect through activation of GalR2 in the brain. The novel galanin analogs represent potential drug leads and a novel pharmaceutical intervention for depression.
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Affiliation(s)
- Indrek Saar
- Institute of Technology, University of Tartu, Tartu, Estonia; Department of Neurochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden
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28
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Saar I, Runesson J, Järv J, Kurrikoff K, Langel Ü. Novel Galanin Receptor Subtype Specific Ligand in Depression Like Behavior. Neurochem Res 2012. [DOI: 10.1007/s11064-012-0933-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Anderson ME, Runesson J, Saar I, Langel U, Robinson JK. Galanin, through GalR1 but not GalR2 receptors, decreases motivation at times of high appetitive behavior. Behav Brain Res 2012; 239:90-3. [PMID: 23142608 DOI: 10.1016/j.bbr.2012.10.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 10/24/2012] [Accepted: 10/29/2012] [Indexed: 01/20/2023]
Abstract
Galanin is a 29/30-amino acid long neuropeptide that has been implicated in many physiological and behavioral functions. Previous research has shown that i.c.v. administration of galanin strongly stimulates food intake in sated rats when food is freely available, but fails to stimulate this consumption when an operant response requirement is present. Using fixed ratio (FR) schedules, we sought to further clarify galanin's role in motivated behavior by administering galanin i.c.v. to rats working on fixed ratio schedules requiring either a low work condition (FR1) or higher work conditions (FR>1) to obtain a 0.2% saccharin reward. Rats in the FR>1 group were assigned to either an FR3, FR5 or FR7 schedule of reinforcement. The rate of reinforcement decreased for only the FR>1 group as compared to saline controls. Furthermore, injections of GalR1 receptor agonist M617 led to a similar, marginally significant decrease in the number of reinforcers received in the FR>1 condition, but a decrease was not seen after injections of GalR2 receptor agonist M1153. Taken together, these results show that galanin may be playing a role in decreasing motivation at times of high appetitive behavior, and that this effect is likely mediated by the GalR1 receptor.
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Affiliation(s)
- Maria E Anderson
- Department of Psychology, Stony Brook University, Stony Brook, NY 11794, USA
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30
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Fang P, Yu M, Shi M, Zhang Z, Sui Y, Guo L, Bo P. Galanin peptide family as a modulating target for contribution to metabolic syndrome. Gen Comp Endocrinol 2012; 179:115-20. [PMID: 22909974 DOI: 10.1016/j.ygcen.2012.07.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 12/23/2022]
Abstract
Metabolic syndrome (MetS) is defined as abdominal central obesity, atherogenic dyslipidemia, insulin resistance, glucose intolerance and hypertension. The rapid increasing prevalence of MetS and the consequent diseases, such as type 2 diabetes mellitus and cardiovascular disorder, are becoming a global epidemic health problem. Despite considerable research into the etiology of this complex disease, the precise mechanism underlying MetS and the association of this complex disease with the development of type 2 diabetes mellitus and increased cardiovascular disease remains elusive. Therefore, researchers continue to actively search for new MetS treatments. Recent animal studies have indicated that the galanin peptide family of peptides may increase food intake, glucose intolerance, fat preference and the risk for obesity and dyslipidemia while decreasing insulin resistance and blood pressure, which diminishes the probability of type 2 diabetes mellitus and hypertension. To date, however, few papers have summarized the role of the galanin peptide family in modulating MetS. Through a summary of available papers and our recent studies, this study reviews the updated evidences of the effect that the galanin peptide family has on the clustering of MetS components, including obesity, dyslipidemia, insulin resistance and hypertension. This line of research will further deepen our understanding of the relationship between the galanin peptide family and the mechanisms underlying MetS, which will help develop new therapeutic strategies for this complex disease.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou, Jiangsu 225300, China
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31
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Fang P, Yu M, Guo L, Bo P, Zhang Z, Shi M. Galanin and its receptors: a novel strategy for appetite control and obesity therapy. Peptides 2012; 36:331-9. [PMID: 22664322 DOI: 10.1016/j.peptides.2012.05.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/24/2012] [Accepted: 05/24/2012] [Indexed: 12/14/2022]
Abstract
The rapid increase in the prevalence of overweight and obesity is becoming an important health problem. Overweight and obesity may cause several metabolic complications, including type 2 diabetes mellitus, hyperlipidemia, high cholesterol, coronary artery disease as well as hypertension. Prevention and treatment of obesity will benefit the treatment of these related diseases. Current strategies for treatment of obesity are not adequately effective and are frequently companied with many side effects. Thus, new ways to treat obesity are urgently needed. Galanin is undoubtedly involved in the regulation of food intake and body weight. The aim of this review is to provide up-to-date knowledge concerning the roles of central and peripheral galanin as well as its receptors in the regulation of metabolism, obesity and appetite. We also highlight the mechanisms of galanin and its receptors in experimental obesity, trying to establish a novel anti-obesity strategy.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Yangzhou University, Yangzhou, Jiangsu, China
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32
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Central nervous system regulation of food intake and energy expenditure: role of galanin-mediated feeding behavior. Neurosci Bull 2012; 27:407-12. [PMID: 22108817 DOI: 10.1007/s12264-011-1841-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Galanin is a neuropeptide widely expressed in the brain. It is implicated in energy expenditure, feeding, and the regulation of body weight. Numerous studies have revealed that galanin regulates food intake via galanin receptors, 5-HT(1A) receptor and adrenergic α-2 receptor. In this review, we summarize recent findings that reveal the essential role of galanin in increasing food intake as well as body weight and that identify the individual galanin receptor subtypes involved in the brain's modulation of food intake and energy expenditure, to provide a theoretical basis for further studies of different aspects of galanin action.
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33
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Webling KEB, Runesson J, Bartfai T, Langel Ü. Galanin receptors and ligands. Front Endocrinol (Lausanne) 2012; 3:146. [PMID: 23233848 PMCID: PMC3516677 DOI: 10.3389/fendo.2012.00146] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/08/2012] [Indexed: 12/13/2022] Open
Abstract
The neuropeptide galanin was first discovered 30 years ago. Today, the galanin family consists of galanin, galanin-like peptide (GALP), galanin-message associated peptide (GMAP), and alarin and this family has been shown to be involved in a wide variety of biological and pathological functions. The effect is mediated through three GPCR subtypes, GalR1-3. The limited number of specific ligands to the galanin receptor subtypes has hindered the understanding of the individual effects of each receptor subtype. This review aims to summarize the current data of the importance of the galanin receptor subtypes and receptor subtype specific agonists and antagonists and their involvement in different biological and pathological functions.
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Affiliation(s)
- Kristin E. B. Webling
- Department of Neurochemistry, Arrhenius Laboratories for Natural Science, Stockholm UniversityStockholm, Sweden
- *Correspondence: Kristin E. B. Webling, Department of Neurochemistry, Arrhenius Laboratories for Natural Science, Stockholm University, Svante Arrheniusv. 21A, 10691 Stockholm, Sweden. e-mail:
| | - Johan Runesson
- Department of Neurochemistry, Arrhenius Laboratories for Natural Science, Stockholm UniversityStockholm, Sweden
| | - Tamas Bartfai
- Molecular and Integrative Neurosciences Department, The Scripps Research InstituteLa Jolla, CA, USA
| | - Ülo Langel
- Department of Neurochemistry, Arrhenius Laboratories for Natural Science, Stockholm UniversityStockholm, Sweden
- Institute of Technology, University of TartuTartu, Estonia
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