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Gimeno-Ferrer F, Eitner A, Schaible HG, Richter F. Galanin diminishes cortical spreading depolarization across rodents - A candidate for treatment? Neurosci Lett 2024; 832:137814. [PMID: 38723760 DOI: 10.1016/j.neulet.2024.137814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/29/2024] [Accepted: 05/06/2024] [Indexed: 05/12/2024]
Abstract
Galanin (Gal) is a neuropeptide with the potential to ameliorate cortical spreading depolarization (CSD), an electrophysiological phenomenon occurring after brain injury or in migraine aura. Gal is expressed in all cortical neurons both in rat and in mouse cortices. Here we investigated whether the effect of Gal on CSD previously described in the rat is conserved in the mouse cortex. In rats, the topical application of Gal to the cortex for 1 h did not induce any change in CSD amplitudes, propagation velocity, or threshold of elicitation. Rather, topical application of Gal for 3 h was necessary to obtain a significant decrease in these CSD parameters and to develop a remarkable increase in the KCl threshold to elicit a CSD in rat cortex. In contrast, the topical application of Gal on cortical surface for 1 h in mice was sufficient to significantly attenuate CSD amplitudes and increase threshold. A thinner cortex, a faster diffusion or different affinity/expression of receptors for Gal are possible reasons to explain this difference in the time course between rats and mice. Our data are relevant to postulate Gal as a potential target for inhibition of CSD under pathological situations such as stroke or ischemia. SIGNIFICANCE STATEMENT: The neuropeptide Galanin (Gal) is expressed in all neurons throughout the cerebral cortex, both in rats and mice, and is able to reduce or even inhibit Cortical Spreading Depolarization, thus, Gal has the potential to control neuronal excitability that may identify Gal as a target in drug development against CSD.
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Affiliation(s)
- Fátima Gimeno-Ferrer
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, D-07740 Jena, Germany; Present address: University of Augsburg, Faculty of Medicine, Institute for Theoretical Medicine, Vascular Biology Lab, D-86159 Augsburg, Germany
| | - Annett Eitner
- Department of Trauma, Hand and Reconstructive Surgery, Experimental Trauma Surgery, Jena University Hospital, D-07740 Jena, Germany
| | - Hans-Georg Schaible
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, D-07740 Jena, Germany
| | - Frank Richter
- Institute of Physiology 1/Neurophysiology, Jena University Hospital, D-07740 Jena, Germany.
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Sun X, Yu Z, Xu Y, Pu S, Gao X. The role of spexin in energy metabolism. Peptides 2023; 164:170991. [PMID: 36914115 DOI: 10.1016/j.peptides.2023.170991] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/15/2023]
Abstract
Spexin, also identified as neuropeptide Q (NPQ), is a 14 amino acid peptide discovered by bioinformatic methods. It has a conserved structure in many species and is widely expressed in the central nervous system and peripheral tissues. It has an associated receptor, galanin receptor 2/3 (GALR2/3). Mature spexin peptides can exert various functions by activating GALR2/3, such as inhibiting food intake, inhibiting lipid absorption, reducing body weight, and improving insulin resistance. Spexin is expressed in the adrenal gland, pancreas, visceral fat, and thyroid, with the highest expression in the adrenal gland, followed by the pancreas. Physiologically, spexin and insulin interact in pancreatic islets. Spexin may be one of the regulators of endocrine function in the pancreas. Spexin is a possible indicator of insulin resistance and it has a variety of functional properties, here we review its role in energy metabolism.
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Affiliation(s)
- Xiaotong Sun
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China.
| | - Ziwei Yu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Yuxin Xu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Shengdan Pu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Xinyuan Gao
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
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3
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Metcalf CS, Gagangras S, Bulaj G, White HS. Synergistic effects of the galanin analog 810-2 with the antiseizure medication levetiracetam in rodent seizure models. Epilepsia 2022; 63:3090-3099. [PMID: 36177529 DOI: 10.1111/epi.17420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE The use of many antiseizure medications (ASMs) is limited due to pharmacoresistance and dose-limiting side effects, suggesting an unmet need for novel therapeutic approaches. The neuropeptide galanin reduces seizures in several preclinical seizure and epilepsy models, but its clinical utility is limited due to rapid metabolism and poor blood-brain barrier penetration. The lead galanin analog 810-2 is systemically bioavailable and reduces seizures when administered alone. Further development of this analog, with the potential for use as an add-on therapy in patients with epilepsy, requires a better understanding of the use of this analog in combination with approved ASMs. We sought to evaluate 810-2 in combination with commonly used ASMs in rodent models of seizures. METHODS The mouse 6-Hz seizure assay was used to test efficacy of 810-2 in combination with levetiracetam (LEV), valproic acid (VPA), or lacosamide (LCM) using a 1:1 dose ratio in isobolographic studies. Further characterization was performed for the combination of 810-2 and LEV in the mouse corneal kindling and rat 6-Hz assays. RESULTS Whereas the combination of 810-2 with VPA and LCM yielded additive interactions, the combination of 810-2 with LEV demonstrated a synergistic interaction in the mouse 6-Hz assay. Supra-additive effects were also observed in the mouse corneal kindling and rat 6-Hz assays for this combination. SIGNIFICANCE The combination of 810-2 with LEV suggests the potential for this galanin analog to be further developed as an add-on therapy for patients with epilepsy, particularly when coadministered with LEV.
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Affiliation(s)
- Cameron S Metcalf
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Saurabh Gagangras
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Grzegorz Bulaj
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
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4
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Caniceiro AB, Bueschbell B, Schiedel AC, Moreira IS. Class A and C GPCR Dimers in Neurodegenerative Diseases. Curr Neuropharmacol 2022; 20:2081-2141. [PMID: 35339177 PMCID: PMC9886835 DOI: 10.2174/1570159x20666220327221830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/21/2022] [Accepted: 03/23/2022] [Indexed: 11/22/2022] Open
Abstract
Neurodegenerative diseases affect over 30 million people worldwide with an ascending trend. Most individuals suffering from these irreversible brain damages belong to the elderly population, with onset between 50 and 60 years. Although the pathophysiology of such diseases is partially known, it remains unclear upon which point a disease turns degenerative. Moreover, current therapeutics can treat some of the symptoms but often have severe side effects and become less effective in long-term treatment. For many neurodegenerative diseases, the involvement of G proteincoupled receptors (GPCRs), which are key players of neuronal transmission and plasticity, has become clearer and holds great promise in elucidating their biological mechanism. With this review, we introduce and summarize class A and class C GPCRs, known to form heterodimers or oligomers to increase their signalling repertoire. Additionally, the examples discussed here were shown to display relevant alterations in brain signalling and had already been associated with the pathophysiology of certain neurodegenerative diseases. Lastly, we classified the heterodimers into two categories of crosstalk, positive or negative, for which there is known evidence.
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Affiliation(s)
- Ana B. Caniceiro
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; ,These authors contributed equally to this work.
| | - Beatriz Bueschbell
- PhD Programme in Experimental Biology and Biomedicine, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão, 3030-789 Coimbra, Portugal; ,These authors contributed equally to this work.
| | - Anke C. Schiedel
- Department of Pharmaceutical & Medicinal Chemistry, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany;
| | - Irina S. Moreira
- University of Coimbra, Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; ,Center for Neuroscience and Cell Biology, Center for Innovative Biomedicine and Biotechnology, 3004-504 Coimbra, Portugal,Address correspondence to this author at the Center for Neuroscience and Cell Biology, Center for Innovative Biomedicine and Biotechnology, 3004-504 Coimbra, Portugal; E-mail:
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5
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Komuro Y, Galas L, Morozov YM, Fahrion JK, Raoult E, Lebon A, Tilot AK, Kikuchi S, Ohno N, Vaudry D, Rakic P, Komuro H. The Role of Galanin in Cerebellar Granule Cell Migration in the Early Postnatal Mouse during Normal Development and after Injury. J Neurosci 2021; 41:8725-8741. [PMID: 34462307 PMCID: PMC8528496 DOI: 10.1523/jneurosci.0900-15.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 11/21/2022] Open
Abstract
Galanin, one of the most inducible neuropeptides, is widely present in developing brains, and its expression is altered by pathologic events (e.g., epilepsy, ischemia, and axotomy). The roles of galanin in brain development under both normal and pathologic conditions have been hypothesized, but the question of how galanin is involved in fetal and early postnatal brain development remains largely unanswered. In this study, using granule cell migration in the cerebellum of early postnatal mice (both sexes) as a model system, we examined the role of galanin in neuronal cell migration during normal development and after brain injury. Here we show that, during normal development, endogenous galanin participates in accelerating granule cell migration via altering the Ca2+ and cAMP signaling pathways. Upon brain injury induced by the application of cold insults, galanin levels decrease at the lesion sites, but increase in the surroundings of lesion sites. Granule cells exhibit the following corresponding changes in migration: (1) slowing down migration at the lesion sites; and (2) accelerating migration in the surroundings of lesion sites. Experimental manipulations of galanin signaling reduce the lesion site-specific changes in granule cell migration, indicating that galanin plays a role in such deficits in neuronal cell migration. The present study suggests that manipulating galanin signaling may be a potential therapeutic target for acutely injured brains during development.SIGNIFICANCE STATEMENT Deficits in neuronal cell migration caused by brain injury result in abnormal development of cortical layers, but the underlying mechanisms remain to be determined. Here, we report that on brain injury, endogenous levels of galanin, a neuropeptide, are altered in a lesion site-specific manner, decreasing at the lesion sites but increasing in the surroundings of lesion sites. The changes in galanin levels positively correlate with the migration rate of immature neurons. Manipulations of galanin signaling ameliorate the effects of injury on neuronal migration and cortical layer development. These results shed a light on galanin as a potential therapeutic target for acutely injured brains during development.
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Affiliation(s)
- Yutaro Komuro
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Ludovic Galas
- Regional Platform for Cell Imaging of Normandy, INSERM, Université de Rouen Normandie, 76000 Rouen, France
| | - Yury M Morozov
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510
| | - Jennifer K Fahrion
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Emilie Raoult
- Regional Platform for Cell Imaging of Normandy, INSERM, Université de Rouen Normandie, 76000 Rouen, France
| | - Alexis Lebon
- Regional Platform for Cell Imaging of Normandy, INSERM, Université de Rouen Normandie, 76000 Rouen, France
| | - Amanda K Tilot
- Department of Genomic Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Shin Kikuchi
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Nobuhiko Ohno
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Aichi 444-8787, Japan
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - David Vaudry
- Regional Platform for Cell Imaging of Normandy, INSERM, Université de Rouen Normandie, 76000 Rouen, France
- Neuropeptides, Neuronal Death and Cell Plasticity Team, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, INSERM U1239, Université de Rouen Normandie, 76000 Rouen, France
| | - Pasko Rakic
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510
- Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, Connecticut 06510
| | - Hitoshi Komuro
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510
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Atabey M, Aykota MR, Özel Mİ, Arslan G. Short-term changes and correlations of plasma spexin, kisspeptin, and galanin levels after laparoscopic sleeve gastrectomy. Surg Today 2021; 51:651-658. [PMID: 33555434 DOI: 10.1007/s00595-021-02240-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/08/2021] [Indexed: 12/24/2022]
Abstract
PURPOSE To determine the circulating levels of spexin, kisspeptin, galanin, and the correlations between these peptides after laparoscopic sleeve gastrectomy (LSG). METHODS The plasma levels of the spexin, kisspeptin, and galanin and metabolic parameters (body mass index, weight loss, % excess weight loss, body fat, fasting glucose, HbA1C, and cholesterol levels) were measured (baseline, 1 month, and 3 months) and correlated in thirty adult individuals with obesity (22 female and 8 male) after LSG. RESULTS The body mass index (BMI), body fat, fasting glucose, total and low-density lipoprotein cholesterol decreased, while high-density lipoprotein cholesterol and % EWL (excess weight loss) increased at 3 months after surgery. The plasma spexin levels increased at 3 months, kisspeptin levels increased at 1 month and stabilized afterward, and galanin levels decreased at 3 months after LSG. Significant correlations were found between metabolic parameters with spexin, kisspeptin, and galanin. In addition, spexin and kisspeptin were negatively correlated with galanin, while spexin was positively correlated with kisspeptin. CONCLUSIONS The biochemical data reveal evidence that LSG causes an increase in the levels of spexin, and kisspeptin and a decrease in galanin levels. Our findings, therefore, suggest a possible interaction between these novel peptides, which have potential roles in obesity and glucose metabolism.
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Affiliation(s)
- Mustafa Atabey
- Department of General Surgery, Faculty of Medicine, University of Biruni, Istanbul, Turkey.
| | - Muhammed Raşid Aykota
- Department of General Surgery, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Mehmet İlker Özel
- Department of General Surgery, Şarkışla Public Hospital, Sivas, Turkey
| | - Gökhan Arslan
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
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Insights into Potential Targets for Therapeutic Intervention in Epilepsy. Int J Mol Sci 2020; 21:ijms21228573. [PMID: 33202963 PMCID: PMC7697405 DOI: 10.3390/ijms21228573] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.
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CSF levels of a set of neurotrophic factors (brain-derived neurotrophic factor, nerve growth factor) and neuropeptides (neuropeptide Y, galanin) in epileptic children. J Clin Neurosci 2020; 76:41-45. [PMID: 32327377 DOI: 10.1016/j.jocn.2020.04.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 04/12/2020] [Indexed: 01/03/2023]
Abstract
This paper aims to investigate the possible roles of a set of neurotrophic factors (brain-derived neurotrophic factor-BDNF, nerve growth factor-NGF) and neuropeptides (neuropeptide Y-NPY, and galanin) in children with active epileptogenesis. The cerebrospinal fluid (CSF) levels of BDNF, NPY, NGF and galanin were measured with enzyme-linked immunosorbent assays in epileptic children (n = 73) and controls (n = 64). There were no significant alterations in the CSF levels of BDNF, NPY and NGF in epileptic children with active clinical seizures compared with the levels of controls. However profoundly depressed galanin levels were found in infants with epileptic encephalopathy (mean ± SD:0.63 ± 0.19 pg/ml) and significantly increased galanin levels were measured in children with drug resistant epilepsy during the period of status epilepticus (mean ± SD: 6.92 ± 1.19, pg/ml pg/ml) compared with the levels of controls. Depressed levels of galanin might reflect a defective anti-epileptogenic effect of galanin in infants with epileptic encephalopathy. On the contrary, increased CSF levels of galanin might be a result of anti-epileptogenic effects of this peptide in epileptic children with status epilepticus.
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Clinical value of a set of neuropeptides in term and preterm neonates with seizures: Brain derived neurotrophic factor, galanin and neuropeptide Y. J Clin Neurosci 2020; 74:168-174. [PMID: 32098713 DOI: 10.1016/j.jocn.2020.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 02/10/2020] [Indexed: 12/26/2022]
Abstract
The aim of our study to investigate clinical value of a set of neuropeptides (brain derived neurotrophic factor-BDNF, galanin and neuropeptide Y-NPY) in critically ill neonates. A total of 53 neonates (preterm: 26, term: 27) evaluated with lumbar pucture for etiologic evaluation were consequtively included into the study. Serum and CSF levels of the neuropeptides were measured in the first 48 h of life. All infants were prospectively followed for prognostic outcome (survival and neurodevelopmental) at the first year of life. The study cohort was categorized into four groups with respect to seizure development; preterm neonates with or without seizure and term neonates with or without seizure. Mean CSF levels of NPY (pg/ml) were significantly higher in term neonates with than those without seizures (389.76 vs. 122.66) and galanin (3.31 vs. 1.55) respectively. Term neonates with seizures had significantly higher serum levels of NPY (ng/mL) as compared with neonates without seizures (54.00 vs. 9.10). No significant difference was noted in serum and CSF levels for the set of neuropeptides in neonates with respect to prognostic outcome. Serum NPY and CSF NPY and galanin levels have a potential role for detection of clinical seizures in term neonates.
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Tekgul H, Simsek E, Erdoğan MA, Yiğittürk G, Erbaş O, Taşkıran D. The potential effects of anticonvulsant drugs on neuropeptides and neurotrophins in pentylenetetrazol kindled seizures in the rat. Int J Neurosci 2019; 130:193-203. [PMID: 31518546 DOI: 10.1080/00207454.2019.1667791] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose: Neuropeptides and neurotrophic factors are thought to be involved in epileptogenesis. This study aims to investigate the potential effects of anticonvulsant drugs on neuropeptides (galanin and neuropeptide Y) and neurotrophic factors (BDNF and NGF) in pentylenetetrazol (PTZ)-kindled seizures in the rat.Methods: Forty-eight adult male Sprague-Dawley rats were included in the study. The animals were divided into 8 groups of six rats. Group 1 was defined as naïve control, and received no medication. Group 2 (PTZ + saline) was treated with sub-convulsive doses of PTZ (35 mg/kg) and saline i.p. for 14 days. For anticonvulsant treatments, Groups 3-8 were treated with 200 mg/kg levetiracetam (PTZ + LEV), 1 mg/kg midazolam (PTZ + MDZ), 80 mg/kg phenytoin (PTZ + PHT), 80 mg/kg topiramate (PTZ + TPR), 40 mg/kg lamotrigine (PTZ + LMT) and 50 mg/kg sodium valproate (PTZ + SV), respectively. All anticonvulsant drugs were injected 30 min prior to PTZ injection throughout 14 days. Following treatment period, behavioral, biochemical and immunohistochemical studies were performed.Results: PTZ + saline group revealed significantly decreased galanin, NPY, BDNF and NGF levels compared to control. PTZ + MDZ group had significantly increased galanin, BDNF and NGF levels compared to saline group. Also, PTZ + LEV group showed increased BDNF levels. PTZ + saline group revealed significantly lower neuron count and higher GFAP (+) cells in hippocampal CA1-CA3 regions. All anticonvulsants significantly reduced hippocampal astrogliosis whereas only midazolam, levetiracetam, sodium valproate and lamotrigine prevented neuronal loss.Conclusion: Our results suggested that anticonvulsant drugs may reduce the severity of seizures, and exert neuroprotective effects by altering the expression of neuropeptides and neurotrophins in the epileptogenic hippocampus.
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Affiliation(s)
- Hasan Tekgul
- Neurology Division, Department of Pediatrics, Ege University School of Medicine, Izmir, Turkey
| | - Erdem Simsek
- Neurology Division, Department of Pediatrics, Ege University School of Medicine, Izmir, Turkey
| | - Mumin Alper Erdoğan
- Department of Physiology, Katip Çelebi University School of Medicine, Izmir, Turkey
| | - Gürkan Yiğittürk
- Department of Histology and Embryology, Muğla Sıtkı Koçman University School of Medicine, Izmir, Turkey
| | - Oytun Erbaş
- Department of Physiology, Istanbul Bilim University School of Medicine, Istanbul, Turkey
| | - Dilek Taşkıran
- Department of Physiology, Ege University School of Medicine, Izmir, Turkey
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11
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Luo H, Liu Z, Liu B, Li H, Yang Y, Xu ZQD. Virus-Mediated Overexpression of ETS-1 in the Ventral Hippocampus Counteracts Depression-Like Behaviors in Rats. Neurosci Bull 2019; 35:1035-1044. [PMID: 31327148 DOI: 10.1007/s12264-019-00412-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 05/27/2019] [Indexed: 12/28/2022] Open
Abstract
ETS-1 is a transcription factor that is a member of the E26 transformation-specific (ETS) family. Galanin receptor 2 (GalR2), a subtype of receptors of the neuropeptide galanin, has been shown to have an antidepressant-like effect after activation in rodents. Our previous study has shown that overexpression of ETS-1 increases the expression of GalR2 in PC12 phaeochromocytoma cells. However, whether ETS-1 has an antidepressant-like effect is still unclear. In this study, we found that chronic mild stress (CMS) decreased the expression of both ETS-1 and GalR2 in the ventral hippocampus of rats. Meanwhile, we demonstrated that overexpression of ETS-1 increased the expression of GalR2 in primary hippocampal neurons. Importantly, we showed that overexpression of ETS-1 in the ventral hippocampus counteracted the depression-like behaviors of CMS rats. Furthermore, we found that overexpression of ETS-1 increased the level of downstream phosphorylated extracellular signal-regulated protein kinases 1 and 2 (p-ERK1/2) of GalR2 in the ventral hippocampus of CMS rats. Taken together, our findings suggest that ETS-1 has an antidepressant-like effect in rats, which might be mediated by increasing the level of GalR2 and its downstream p-ERK1/2 in the ventral hippocampus.
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Affiliation(s)
- Hanjiang Luo
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Major Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Zijin Liu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Major Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Bo Liu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Major Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Hui Li
- Department of Anatomy, Capital Medical University, Beijing, 100069, China
| | - Yutao Yang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Major Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China.
| | - Zhi-Qing David Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Major Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China.
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12
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Drexel M, Locker F, Kofler B, Sperk G. Effects of galanin receptor 2 and receptor 3 knockout in mouse models of acute seizures. Epilepsia 2018; 59:e166-e171. [PMID: 30298565 PMCID: PMC6282553 DOI: 10.1111/epi.14573] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/07/2018] [Accepted: 09/10/2018] [Indexed: 12/04/2022]
Abstract
There exists solid evidence that endogenous galanin and galanin agonists exert anticonvulsive actions mediated both by galanin 1 receptor (GAL1‐R) and galanin 2 receptor (GAL2‐R). We have now investigated whether depletion of the recently identified third galanin receptor, GAL3‐R, and that of GAL2‐R, alters the threshold to the systemically applied γ‐aminobutyric acid (GABA) antagonist pentylenetetrazole (PTZ) or to intrahippocampally administered kainic acid (KA). In neither model, GAL3‐KO mice differed in their latency to the first seizure, mean seizure duration, total number of seizures, or time spent in seizures compared to wild‐type controls. In addition, consistent with previous data, the response to PTZ was not altered in GAL2‐KO mice. In contrast, intrahippocampal KA resulted in a significantly increased number of seizures and time spent in seizures in GAL2‐KO mice, although the latency to the first seizure and the duration of individual seizures was not altered. These results are consistent with the previous data showing that GAL2‐R knockdown does not affect the number of perforant path stimulations required for initiating status epilepticus but significantly increases the seizure severity during the ongoing status. In conclusion, our data support a specific role of GAL2‐R but not of GAL3‐R in mediating the anticonvulsive actions of endogenous galanin.
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Affiliation(s)
- Meinrad Drexel
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Felix Locker
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Kofler
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Günther Sperk
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
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Lin CY, Huang T, Zhao L, Zhong LLD, Lam WC, Fan BM, Bian ZX. Circulating Spexin Levels Negatively Correlate With Age, BMI, Fasting Glucose, and Triglycerides in Healthy Adult Women. J Endocr Soc 2018; 2:409-419. [PMID: 29687092 PMCID: PMC5905385 DOI: 10.1210/js.2018-00020] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/29/2018] [Indexed: 12/15/2022] Open
Abstract
Context Spexin is a newly identified neuropeptide that is involved in satiety control, glucose, and lipids metabolism. It has also been related to human diseases, such as obesity and type 2 diabetes. However, whether spexin changes with age or not is still unclear. Objective The aim of this study is to investigate the relationship between circulating spexin levels and age and to study their interaction effects on body mass index (BMI), fasting glucose, and -lipids. Design and Participants This is a cross-sectional study, including 68 healthy adult women whose ages are in a wide range (minimum: 23; median: 38.5; maximum: 64). Outcome Measures The serum spexin levels were measured by an enzyme-linked immunosorbent assay. Fasting glucose, total cholesterol, triglycerides (TG), alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, urea, and creatinine were measured by routine biochemical test. Shapiro-Wilk’s test, Spearman and Pearson correlation analyses, χ2 test, and two-way analysis of variance were used to interpret the data. Results Serum spexin levels are significantly correlated with age (Spearman r = −0.277, P = 0.022), BMI (Spearman r = −0.445, P < 0.001), fasting glucose (Spearman r = −0.302, P = 0.014), and TG (Spearman r = −0.324, P = 0.008). Spexin levels independently predict the risk of high BMI and high fasting glucose. No interaction effects of spexin and age on BMI and fasting glucose were found. Conclusions Circulating spexin levels decrease with age, suggesting a possible role of this peptide in aging-related functions and disorders. Further investigations are needed to expand the clinical significance of this finding.
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Affiliation(s)
- Cheng-Yuan Lin
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Yunnan Minzu University-Hong Kong Baptist University Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Kunming, China
| | - Tao Huang
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China
| | - Ling Zhao
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China
| | - Linda L D Zhong
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China
| | - Wai Ching Lam
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China
| | - Bao-Min Fan
- Yunnan Minzu University-Hong Kong Baptist University Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Kunming, China
| | - Zhao-Xiang Bian
- Institute of Brain and Gut Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.,Hong Kong Chinese Medicine Clinical Study Centre, Hong Kong Baptist University, Hong Kong Special Administrative Region, China
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14
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Navidhamidi M, Ghasemi M, Mehranfard N. Epilepsy-associated alterations in hippocampal excitability. Rev Neurosci 2018; 28:307-334. [PMID: 28099137 DOI: 10.1515/revneuro-2016-0059] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/03/2016] [Indexed: 11/15/2022]
Abstract
The hippocampus exhibits a wide range of epilepsy-related abnormalities and is situated in the mesial temporal lobe, where limbic seizures begin. These abnormalities could affect membrane excitability and lead to overstimulation of neurons. Multiple overlapping processes refer to neural homeostatic responses develop in neurons that work together to restore neuronal firing rates to control levels. Nevertheless, homeostatic mechanisms are unable to restore normal neuronal excitability, and the epileptic hippocampus becomes hyperexcitable or hypoexcitable. Studies show that there is hyperexcitability even before starting recurrent spontaneous seizures, suggesting although hippocampal hyperexcitability may contribute to epileptogenesis, it alone is insufficient to produce epileptic seizures. This supports the concept that the hippocampus is not the only substrate for limbic seizure onset, and a broader hyperexcitable limbic structure may contribute to temporal lobe epilepsy (TLE) seizures. Nevertheless, seizures also occur in conditions where the hippocampus shows a hypoexcitable phenotype. Since TLE seizures most often originate in the hippocampus, it could therefore be assumed that both hippocampal hypoexcitability and hyperexcitability are undesirable states that make the epileptic hippocampal network less stable and may, under certain conditions, trigger seizures.
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15
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Abstract
INTRODUCTION Epilepsy is one of the most common neurological diseases affecting approximately 50 million people worldwide. Despite many advances in epilepsy research, nearly a third of patients with epilepsy have refractory or pharmacoresistant epilepsy. Despite the approval of a dozen antiepileptic drugs (AEDs) over the past decade, there are no agents that halt the development of epilepsy. Thus, newer and better AEDs that can prevent refractory seizures and modify the disease are needed for curing epilepsy. Areas covered: In this article, we highlight the recent advances and emerging trends in new and innovative drugs for epilepsy and seizure disorders. We review in detail top new drugs that are currently in clinical trials or agents that are under development and have novel mechanisms of action. Expert commentary: Among the new agents under clinical investigation, the majority were originally developed for treating other neurological diseases (everolimus, fenfluramine, nalutozan, bumetanide, and valnoctamide); several have mechanisms of action similar to those of conventional AEDs (AP, ganaxolone, and YKP3089); and some new agents represent novel mechanisms of actions (huperzine-A, cannabidiol, tonabersat, and VX-765).
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Affiliation(s)
- Iyan Younus
- a Department of Neuroscience and Experimental Therapeutics, College of Medicine , Texas A&M Health Science Center , Bryan , TX , USA
| | - Doodipala Samba Reddy
- a Department of Neuroscience and Experimental Therapeutics, College of Medicine , Texas A&M Health Science Center , Bryan , TX , USA
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16
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Preclinical Analgesic and Safety Evaluation of the GalR2-preferring Analog, NAX 810-2. Neurochem Res 2017; 42:1983-1994. [PMID: 28382595 DOI: 10.1007/s11064-017-2229-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 10/24/2022]
Abstract
The potential clinical utility of galanin peptidic analogs has been hindered by poor metabolic stability, lack of brain penetration, and hyperglycemia. In addition to possessing potent anticonvulsant efficacy, galanin analogs are analgesic in various assays. The purpose of these studies was to evaluate the lead galanin receptor type 2 (GalR2)-preferring analog, NAX 810-2, in various pain assays, as well as determine any potential for insulin inhibition, growth hormone stimulation, and cognitive impairment. NAX 810-2 was evaluated in mouse (carrageenan, formalin, tail flick, plantar incision) and rat pain models (partial sciatic nerve ligation). NAX 810-2 dose-dependently increased paw withdrawal latency following plantar administration of carrageenan (ED50 4.7 mg/kg). At a dose of 8 mg/kg, NAX 810-2 significantly attenuated nociceptive behaviors following plantar administration of formalin, and this was observed for both phase I (acute) and phase II (inflammatory) components of the formalin behavioral response. NAX-810-2 was active at higher doses in the mouse tail flick model (ED50 20.2 mg/kg) and similarly, reduced mechanical allodynia following plantar incision in mice at a dose of 24 mg/kg. NAX 810-2 also reduced mechanical allodynia in the partial sciatic nerve ligation model at a dose of 4 mg/kg. In addition, NAX 810-2 did not impair insulin secretion at doses of 2.5 and 8 mg/kg (acutely) or at a dose of 8 mg/kg given daily for 5 days. Similarly, 8 mg/kg (twice daily, 5 days) of NAX 810-2 did not increase growth hormone levels. These results demonstrate that NAX 810-2 possesses a favorable pre-clinical profile as a novel and first-in-class analgesic.
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Bialer M, Johannessen SI, Levy RH, Perucca E, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Thirteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIII). Epilepsia 2017; 58:181-221. [PMID: 28111749 DOI: 10.1111/epi.13634] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 01/05/2023]
Abstract
The Thirteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIII) took place in Madrid, Spain, on June 26-29, 2016, and was attended by >200 delegates from 31 countries. The present Progress Report provides an update on experimental and clinical results for drugs presented at the Conference. Compounds for which summary data are presented include an AED approved in 2016 (brivaracetam), 12 drugs in phase I-III clinical development (adenosine, allopregnanolone, bumetanide, cannabidiol, cannabidivarin, 2-deoxy-d-glucose, everolimus, fenfluramine, huperzine A, minocycline, SAGE-217, and valnoctamide) and 6 compounds or classes of compounds for which only preclinical data are available (bumetanide derivatives, sec-butylpropylacetamide, FV-082, 1OP-2198, NAX 810-2, and SAGE-689). Overall, the results presented at the Conference show that considerable efforts are ongoing into discovery and development of AEDs with potentially improved therapeutic profiles compared with existing agents. Many of the drugs discussed in this report show innovative mechanisms of action and many have shown promising results in patients with pharmacoresistant epilepsies, including previously neglected rare and severe epilepsy syndromes.
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Affiliation(s)
- Meir Bialer
- Faculty of Medicine, School of Pharmacy and David R. Bloom Center for Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Svein I Johannessen
- The National Center for Epilepsy, Sandvika, Norway.,Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - René H Levy
- Department of Pharmaceutics and Neurological Surgery, University of Washington, Seattle, Washington, U.S.A
| | - Emilio Perucca
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.,C. Mondino National Neurological Institute, Pavia, Italy
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, U.S.A
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Metcalf CS, Klein BD, McDougle DR, Zhang L, Kaufmann D, Bulaj G, White HS. Preclinical evaluation of intravenous NAX 810-2, a novel GalR2-preferring analog, for anticonvulsant efficacy and pharmacokinetics. Epilepsia 2017; 58:239-246. [PMID: 28098336 DOI: 10.1111/epi.13647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2016] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Potential clinical utility of galanin or peptidic analogs has been hindered by poor metabolic stability, lack of brain penetration, and hyperglycemia due to galanin receptor subtype 1 (GalR1) activation. NAX 810-2, a galanin receptor subtype 2 (GalR2)-preferring galanin analog, possesses 15-fold greater affinity for GalR2 over GalR1 and protects against seizures in the mouse 6 Hz, corneal kindling, and Frings audiogenic seizure models. The purpose of these studies was to further evaluate the preclinical efficacy and pharmacokinetics of NAX 810-2 in mice. METHODS NAX 810-2 was administered by intravenous (i.v.; tail vein, bolus) injection to fully kindled (corneal kindling assay) or naive CF-1 mice (6 Hz assay and pharmacokinetic studies). Plasma NAX 810-2 levels were determined from trunk blood samples. NAX 810-2 was also added to human plasma at various concentrations for determination of plasma protein binding. RESULTS In the mouse corneal kindling model, NAX 810-2 dose-dependently blocked seizures following intravenous administration (median effective dose [ED50 ], 0.5 mg/kg). In the mouse 6 Hz (32 mA) seizure model, it was demonstrated that NAX 810-2 dose-dependently blocked seizures following bolus administration (0.375-1.5 mg/kg, i.v.; ED50 , 0.7 mg/kg), with a time-to-peak effect of 0.5 h posttreatment. Motor impairment was observed at 1.5 mg/kg, i.v., whereas one-half of this dose, 0.75 mg/kg, i.v., was maximally effective in the 6 Hz test. Plasma levels of NAX 810-2 show linear pharmacokinetics following intravenous administration and a half-life of 1.2 h. Functional agonist activity studies demonstrate that NAX 810-2 effectively activates GalR2 at therapeutic concentrations. SIGNIFICANCE These studies further suggest the potential utility of NAX 810-2 as a novel therapy for epilepsy.
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Affiliation(s)
- Cameron S Metcalf
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,NeuroAdjuvants, Inc., Salt Lake City, Utah, U.S.A
| | - Brian D Klein
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,NeuroAdjuvants, Inc., Salt Lake City, Utah, U.S.A
| | | | - Liuyin Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A
| | - Dan Kaufmann
- Department of Neurology, University of Utah Health Sciences Center, Salt Lake City, Utah, U.S.A
| | - Grzegorz Bulaj
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A
| | - H Steve White
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, U.S.A
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19
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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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20
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He B, Fang P, Guo L, Shi M, Zhu Y, Xu B, Bo P, Zhang Z. Beneficial effects of neuropeptide galanin on reinstatement of exercise-induced somatic and psychological trauma. J Neurosci Res 2016; 95:1036-1043. [DOI: 10.1002/jnr.23869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 07/01/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Biao He
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention Ministry of Education, School of Physical Education and Health Care, East China Normal University; Shanghai China
| | - Penghua Fang
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Lili Guo
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Mingyi Shi
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Yan Zhu
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Bo Xu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention Ministry of Education, School of Physical Education and Health Care, East China Normal University; Shanghai China
| | - Ping Bo
- Key Laboratory of Gerontal Medicine, Medical College, Yangzhou University; Yangzhou Jiangsu China
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
| | - Zhenwen Zhang
- Department of Endocrinology; Clinical Medical College, Yangzhou University; Yangzhou Jiangsu China
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21
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Constantin S, Wray S. Galanin Activates G Protein Gated Inwardly Rectifying Potassium Channels and Suppresses Kisspeptin-10 Activation of GnRH Neurons. Endocrinology 2016; 157:3197-212. [PMID: 27359210 PMCID: PMC4967115 DOI: 10.1210/en.2016-1064] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
GnRH neurons are regulated by hypothalamic kisspeptin neurons. Recently, galanin was identified in a subpopulation of kisspeptin neurons. Although the literature thoroughly describes kisspeptin activation of GnRH neurons, little is known about the effects of galanin on GnRH neurons. This study investigated whether galanin could alter kisspeptin signaling to GnRH neurons. GnRH cells maintained in explants, known to display spontaneous calcium oscillations, and a long-lasting calcium response to kisspeptin-10 (kp-10), were used. First, transcripts for galanin receptors (GalRs) were examined. Only GalR1 was found in GnRH neurons. A series of experiments was then performed to determine the action of galanin on kp-10 activated GnRH neurons. Applied after kp-10 activation, galanin 1-16 (Gal1-16) rapidly suppressed kp-10 activation. Applied with kp-10, Gal1-16 prevented kp-10 activation until its removal. To determine the mechanism by which galanin inhibited kp-10 activation of GnRH neurons, Gal1-16 and galanin were applied to spontaneously active GnRH neurons. Both inhibited GnRH neuronal activity, independent of GnRH neuronal inputs. This inhibition was mimicked by a GalR1 agonist but not by GalR2 or GalR2/3 agonists. Although Gal1-16 inhibition relied on Gi/o signaling, it was independent of cAMP levels but sensitive to blockers of G protein-coupled inwardly rectifying potassium channels. A newly developed bioassay for GnRH detection showed Gal1-16 decreased the kp-10-evoked GnRH secretion below detection threshold. Together, this study shows that galanin is a potent regulator of GnRH neurons, possibly acting as a physiological break to kisspeptin excitation.
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Affiliation(s)
- Stephanie Constantin
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
| | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
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22
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Characterization of the Rat GAL2R Promoter: Positive Role of ETS-1 in Regulation of the Rat GAL2R Gene in PC12 Cells. Mol Neurobiol 2016; 54:4421-4431. [PMID: 27349435 DOI: 10.1007/s12035-016-9986-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
Abstract
Galanin receptor 2 (GAL2R) is a G protein-coupled receptor for the neuropeptide galanin that regulates many important physiological functions and pathological processes. To investigate the molecular mechanism governing GAL2R gene transcription, the rat GAL2R promoter was isolated and analyzed. We found that the region from -320 to -300 of the GAL2R promoter contains two putative ETS-1 elements and plays an important role in regulating GAL2R promoter activity. We also showed that transcription factor ETS-1 bound to this region in vitro and in vivo. Overexpression of ETS-1 significantly increased GAL2R promoter activity and transcription of the GAL2R gene, whereas knockdown of ETS-1 produced the opposite effects. In addition, we showed that ETS-1 recruited co-activator p300 to the GAL2R promoter. These data indicate a role for ETS-1 in the control of the GAL2R gene expression and provide a basis for understanding the transcriptional regulation of the GAL2R gene.
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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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Do traditional anti-seizure drugs have a future? A review of potential anti-seizure drugs in clinical development. Pharmacol Res 2016; 104:38-48. [DOI: 10.1016/j.phrs.2015.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/08/2015] [Accepted: 12/08/2015] [Indexed: 12/11/2022]
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Differential Effect of Neuropeptides on Excitatory Synaptic Transmission in Human Epileptic Hippocampus. J Neurosci 2015; 35:9622-31. [PMID: 26134645 DOI: 10.1523/jneurosci.3973-14.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Development of novel disease-modifying treatment strategies for neurological disorders, which at present have no cure, represents a major challenge for today's neurology. Translation of findings from animal models to humans represents an unresolved gap in most of the preclinical studies. Gene therapy is an evolving innovative approach that may prove useful for clinical applications. In animal models of temporal lobe epilepsy (TLE), gene therapy treatments based on viral vectors encoding NPY or galanin have been shown to effectively suppress seizures. However, how this translates to human TLE remains unknown. A unique possibility to validate these animal studies is provided by a surgical therapeutic approach, whereby resected epileptic tissue from temporal lobes of pharmacoresistant patients are available for neurophysiological studies in vitro. To test whether NPY and galanin have antiepileptic actions in human epileptic tissue as well, we applied these neuropeptides directly to human hippocampal slices in vitro. NPY strongly decreased stimulation-induced EPSPs in dentate gyrus and CA1 (up to 30 and 55%, respectively) via Y2 receptors, while galanin had no significant effect. Receptor autoradiographic binding revealed the presence of both NPY and galanin receptors, while functional receptor binding was only detected for NPY, suggesting that galanin receptor signaling may be impaired. These results underline the importance of validating findings from animal studies in human brain tissue, and advocate for NPY as a more appropriate candidate than galanin for future gene therapy trials in pharmacoresistant TLE patients.
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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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Spexin Enhances Bowel Movement through Activating L-type Voltage-dependent Calcium Channel via Galanin Receptor 2 in Mice. Sci Rep 2015; 5:12095. [PMID: 26160593 PMCID: PMC4498193 DOI: 10.1038/srep12095] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 06/05/2015] [Indexed: 12/21/2022] Open
Abstract
A novel neuropeptide spexin was found to be broadly expressed in various endocrine and nervous tissues while little is known about its functions. This study investigated the role of spexin in bowel movement and the underlying mechanisms. In functional constipation (FC) patients, serum spexin levels were significantly decreased. Consistently, in starved mice, the mRNA of spexin was significantly decreased in intestine and colon. Spexin injection increased the velocity of carbon powder propulsion in small intestine and decreased the glass beads expulsion time in distal colon in mice. Further, spexin dose-dependently stimulated the intestinal/colonic smooth muscle contraction. Galanin receptor 2 (GALR2) antagonist M871, but not Galanin receptor 3 (GALR3) antagonist SNAP37899, effectively suppressed the stimulatory effects of spexin on intestinal/colonic smooth muscle contraction, which could be eliminated by extracellular [Ca2+] removal and L-type voltage-dependentCa2+ channel (VDCC) inhibitor nifedipine. Besides, spexin dramatically increased the [Ca2+]i in isolated colonic smooth muscle cells. These data indicate that spexin can act on GALR2 receptor to regulate bowel motility by activating L-type VDCC. Our findings provide evidence for important physiological roles of spexin in GI functions. Selective action on spexin pathway might have therapeutic effects on GI diseases with motility disorders.
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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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Bialer M, Johannessen SI, Levy RH, Perucca E, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Twelfth Eilat Conference (EILAT XII). Epilepsy Res 2015; 111:85-141. [PMID: 25769377 DOI: 10.1016/j.eplepsyres.2015.01.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
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Yang X, Wang X. Potential mechanisms and clinical applications of mild hypothermia and electroconvulsive therapy on refractory status epilepticus. Expert Rev Neurother 2014; 15:135-44. [DOI: 10.1586/14737175.2015.992415] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Barreda-Gómez G, Giralt MT, Pazos A, Rodríguez-Puertas R. Galanin activated Gi/o-proteins in human and rat central nervous systems. Neuropeptides 2014; 48:295-304. [PMID: 25043784 DOI: 10.1016/j.npep.2014.06.002] [Citation(s) in RCA: 8] [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: 12/13/2013] [Revised: 05/19/2014] [Accepted: 06/16/2014] [Indexed: 11/29/2022]
Abstract
The neuropeptide galanin (GAL) is involved in the control of hormone secretion, nociception, feeding behavior, attention, learning and memory. The anatomical localization of galanin receptors in the brain has been described using autoradiography and immunohistochemistry, but both techniques are limited by the availability of specific radioligands or antibodies. Functional autoradiography provides an alternative method by combining anatomical resolution and information of the activity mediated by G-protein coupled receptors. The present study analyzes the functional GAL receptors coupled to Gi/o-proteins in human and rat brain nuclei using [(35)S]GTPγS autoradiography. The results show the anatomical distribution of Gi/o-proteins activated by GAL receptors that trigger intracellular signaling mechanisms. The activity mediated by GAL receptors in human and rat brain showed a good correlation of the net stimulation in areas such as spinal cord, periaqueductal gray, putamen, CA3 layers of hippocampus, substantia nigra and diverse thalamic nuclei. The functional GAL receptors coupled to Gi/o-proteins showed a similar pattern for both species in most of the areas analyzed, but some discrete nuclei showed differences in the activity mediated by GAL, such as the ventroposteromedial thalamic nucleus, or areas that regulate learning and memory processes in the hippocampus. Taken into consideration the present results, the rat could be used as an experimental model for the study of the physiological role of GAL-mediated neurotransmission and the modulation of GAL receptors activity in the human CNS.
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Affiliation(s)
- G Barreda-Gómez
- Dept. Pharmacology, Faculty of Medicine and Odontology, University of the Basque Country, E-48940 Leioa, Vizcaya, Spain
| | - M T Giralt
- Dept. Pharmacology, Faculty of Medicine and Odontology, University of the Basque Country, E-48940 Leioa, Vizcaya, Spain
| | - A Pazos
- Dept. Physiology and Pharmacology, Faculty of Medicine, University of Cantabria, 39011 Santander, Spain
| | - R Rodríguez-Puertas
- Dept. Pharmacology, Faculty of Medicine and Odontology, University of the Basque Country, E-48940 Leioa, Vizcaya, Spain.
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Cordero-Llana O, Rinaldi F, Brennan PA, Wynick D, Caldwell MA. Galanin promotes neuronal differentiation from neural progenitor cells in vitro and contributes to the generation of new olfactory neurons in the adult mouse brain. Exp Neurol 2014; 256:93-104. [PMID: 24726665 DOI: 10.1016/j.expneurol.2014.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 03/28/2014] [Accepted: 04/01/2014] [Indexed: 12/12/2022]
Abstract
Galanin is a pleiotropic neuropeptide widely expressed in the nervous system. It plays a role in many diverse physiological functions - including nociception, cognition and metabolism regulation - and acts as neurotrophic/neuroprotective factor for several neuronal populations. In this article we sought to determine the role of galanin on neural stem cell function and its contribution to the plasticity of the nervous system. Here we show that galanin and its receptors are expressed in neural progenitor cells (NPCs) isolated from the developing striatum. Stimulation with galanin results in upregulation of Bcl-Xl, Bcl-2, Mash-1 and Olig-2 that are part of well known pro-survival/pro-neuronal signalling pathways. Accordingly, treatment with galanin increases the number of neurons upon differentiation from these progenitors. We then show that these effects are recapitulated in NPCs isolated from the adult subventricular zone (SVZ), where galanin increases the total number of neurons and the number of newly-generated neurons upon differentiation in vitro. The significance of these findings is highlighted in the adult brain where loss of galanin leads to a marked decrease in the rate of adult SVZ neurogenesis and a reduction in the number of newly generated cells in the olfactory bulb. Interestingly, Gal-KO mice display normal performances in simple tasks of olfactory detection and discrimination, which points to the existence of a certain degree of redundancy in SVZ neurogenesis. Our findings establish the role of galanin as a modulator of neural stem cell function and support the importance of galanin for brain plasticity and repair.
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Affiliation(s)
- Oscar Cordero-Llana
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, School of Clinical Sciences, University of Bristol, BS1 3NY, UK
| | - Federica Rinaldi
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, School of Clinical Sciences, University of Bristol, BS1 3NY, UK
| | - Peter A Brennan
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, BS8 1TD, UK
| | - David Wynick
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, BS8 1TD, UK; School of Clinical Sciences, University of Bristol, Medical Sciences Building, University Walk, BS8 1TD, UK.
| | - Maeve A Caldwell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, School of Clinical Sciences, University of Bristol, BS1 3NY, UK; School of Clinical Sciences, University of Bristol, Medical Sciences Building, University Walk, BS8 1TD, UK.
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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: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [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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Clynen E, Swijsen A, Raijmakers M, Hoogland G, Rigo JM. Neuropeptides as targets for the development of anticonvulsant drugs. Mol Neurobiol 2014; 50:626-46. [PMID: 24705860 PMCID: PMC4182642 DOI: 10.1007/s12035-014-8669-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 02/27/2014] [Indexed: 11/04/2022]
Abstract
Epilepsy is a common neurological disorder characterized by recurrent seizures. These seizures are due to abnormal excessive and synchronous neuronal activity in the brain caused by a disruption of the delicate balance between excitation and inhibition. Neuropeptides can contribute to such misbalance by modulating the effect of classical excitatory and inhibitory neurotransmitters. In this review, we discuss 21 different neuropeptides that have been linked to seizure disorders. These neuropeptides show an aberrant expression and/or release in animal seizure models and/or epilepsy patients. Many of these endogenous peptides, like adrenocorticotropic hormone, angiotensin, cholecystokinin, cortistatin, dynorphin, galanin, ghrelin, neuropeptide Y, neurotensin, somatostatin, and thyrotropin-releasing hormone, are able to suppress seizures in the brain. Other neuropeptides, such as arginine-vasopressine peptide, corticotropin-releasing hormone, enkephalin, β-endorphin, pituitary adenylate cyclase-activating polypeptide, and tachykinins have proconvulsive properties. For oxytocin and melanin-concentrating hormone both pro- and anticonvulsive effects have been reported, and this seems to be dose or time dependent. All these neuropeptides and their receptors are interesting targets for the development of new antiepileptic drugs. Other neuropeptides such as nesfatin-1 and vasoactive intestinal peptide have been less studied in this field; however, as nesfatin-1 levels change over the course of epilepsy, this can be considered as an interesting marker to diagnose patients who have suffered a recent epileptic seizure.
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Affiliation(s)
- Elke Clynen
- Biomedical Research Institute BIOMED, Hasselt University, Martelarenlaan 42, 3500, Hasselt, Belgium,
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Li L, Yu L, Kong Q. Exogenous galanin attenuates spatial memory impairment and decreases hippocampal beta-amyloid levels in rat model of Alzheimer's disease. Int J Neurosci 2013; 123:759-65. [DOI: 10.3109/00207454.2013.800976] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Agasse F, Xapelli S, Coronas V, Christiansen SH, Rosa AI, Sardá-Arroyo L, Santos T, Ferreira R, Schitine C, Harnois T, Bourmeyster N, Bragança J, Bernardino L, Malva JO, Woldbye DP. Galanin Promotes Neuronal Differentiation in Murine Subventricular Zone Cell Cultures. Stem Cells Dev 2013; 22:1693-708. [DOI: 10.1089/scd.2012.0161] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Fabienne Agasse
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Sara Xapelli
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Valérie Coronas
- Institut de Physiologie et Biologie Cellulaires, University of Poitiers, CNRS FRE 3511, Poitiers Cedex, France
| | - Søren H. Christiansen
- Protein Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Alexandra I. Rosa
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Laura Sardá-Arroyo
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Tiago Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Raquel Ferreira
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - Clarissa Schitine
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
- Neurochemistry Laboratory, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Thomas Harnois
- Institut de Physiologie et Biologie Cellulaires, University of Poitiers, CNRS FRE 3511, Poitiers Cedex, France
- CHU de Poitiers, Poitiers Cedex, France
| | - Nicolas Bourmeyster
- Institut de Physiologie et Biologie Cellulaires, University of Poitiers, CNRS FRE 3511, Poitiers Cedex, France
- CHU de Poitiers, Poitiers Cedex, France
| | - José Bragança
- Centre for Molecular and Structural Biomedicine, Institute for Biotechnology and Bioengineering, University of Algarve, Faro, Portugal
| | - Liliana Bernardino
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - João O. Malva
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
| | - David P.D. Woldbye
- Protein Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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Kothandan G, Gadhe CG, Cho SJ. Theoretical Characterization of Galanin Receptor Type 3 (Gal3) and Its Interaction with Agonist (GALANIN) and Antagonists (SNAP 37889 and SNAP 398299): AnIn SilicoAnalysis. Chem Biol Drug Des 2013; 81:757-74. [DOI: 10.1111/cbdd.12128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 02/13/2013] [Accepted: 02/25/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Gugan Kothandan
- Department of Bio-New Drug Development; College of Medicine; Chosun University; Gwangju; 501-759; Korea
| | - Changdev G. Gadhe
- Department of Bio-New Drug Development; College of Medicine; Chosun University; Gwangju; 501-759; Korea
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Sui Y, Vermeulen R, Hökfelt T, Horne MK, Stanić D. Female mice lacking cholecystokinin 1 receptors have compromised neurogenesis, and fewer dopaminergic cells in the olfactory bulb. Front Cell Neurosci 2013; 7:13. [PMID: 23459364 PMCID: PMC3584826 DOI: 10.3389/fncel.2013.00013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/03/2013] [Indexed: 12/17/2022] Open
Abstract
Neurogenesis in the adult rodent brain is largely restricted to the subependymal zone (SVZ) of the lateral ventricle and subgranular zone (SGZ) of the dentate gyrus (DG). We examined whether cholecystokinin (CCK) through actions mediated by CCK1 receptors (CCK1R) is involved in regulating neurogenesis. Proliferating cells in the SVZ, measured by 5-bromo-2-deoxyuridine (BrdU) injected 2 h prior to death or by immunoreactivity against Ki67, were reduced by 37 and 42%, respectively, in female (but not male) mice lacking CCK1Rs (CCK1R(-/-)) compared to wild-type (WT). Generation of neuroblasts in the SVZ and rostral migratory stream (RMS) was also affected, since the number of doublecortin (DCX)-immunoreactive (ir) neuroblasts in these regions decreased by 29%. In the SGZ of female CCK1R(-/-) mice, BrdU-positive (+), and Ki67-ir cells were reduced by 38 and 56%, respectively, while DCX-ir neuroblasts were down 80%. Subsequently, the effect of reduced SVZ/SGZ proliferation on the generation and survival of mature adult-born cells in female CCK1R(-/-) mice was examined. In the OB granule cell layer (GCL), the number of neuronal nuclei (NeuN)-ir and calretinin-ir cells was stable compared to WT, and 42 days after BrdU injections, the number of BrdU+ cells co-expressing GABA- or NeuN-like immunoreactivity (LI) was similar. Compared to WT, the granule cell layer of the DG in female CCK1R(-/-) mice had a similar number of calbindin-ir cells and BrdU+ cells co-expressing calbindin-LI 42 days after BrdU injections. However, the OB glomerular layer (GL) of CCK1R(-/-) female mice had 11% fewer NeuN-ir cells, 23% less TH-ir cells, and a 38% and 29% reduction in BrdU+ cells that co-expressed TH-LI or GABA-LI, respectively. We conclude that CCK, via CCK1Rs, is involved in regulating the generation of proliferating cells and neuroblasts in the adult female mouse brain, and mechanisms are in place to maintain steady neuronal populations in the OB and DG when the rate of proliferation is altered.
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Affiliation(s)
- Yi Sui
- Neurodegeneration Division, Florey Institute of Neuroscience and Mental Health, University of Melbourne Parkville, VIC, Australia ; Department of Neurology, Shenyang First People's Hospital Shenyang, China
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Casillas-Espinosa PM, Powell KL, O'Brien TJ. Regulators of synaptic transmission: roles in the pathogenesis and treatment of epilepsy. Epilepsia 2013; 53 Suppl 9:41-58. [PMID: 23216578 DOI: 10.1111/epi.12034] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synaptic transmission is the communication between a presynaptic and a postsynaptic neuron, and the subsequent processing of the signal. These processes are complex and highly regulated, reflecting their importance in normal brain functioning and homeostasis. Sustaining synaptic transmission depends on the continuing cycle of synaptic vesicle formation, release, and endocytosis, which requires proteins such as dynamin, syndapin, synapsin, and synaptic vesicle protein 2A. Synaptic transmission is regulated by diverse mechanisms, including presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors and signaling, and modulators of neurotransmission. Neurotransmitters released presynaptically can bind to their postsynaptic receptors, the inhibitory γ-aminobutyric acid (GABA)ergic receptors or the excitatory glutamate receptors. Once released, glutamate activates a variety of postsynaptic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA), kainate, and metabotropic receptors. The activation of the receptors triggers downstream signaling cascades generating a vast array of effects, which can be modulated by a numerous auxiliary regulatory subunits. Moreover, different neuropeptides such as neuropeptide Y, brain-derived neurotrophic factor (BDNF), somatostatin, ghrelin, and galanin, act as regulators of diverse synaptic functions and along with the classic neurotransmitters. Abnormalities in the regulation of synaptic transmission play a critical role in the pathogenesis of numerous brain diseases, including epilepsy. This review focuses on the different mechanisms involved in the regulation of synaptic transmission, which may play a role in the pathogenesis of epilepsy: the presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors, and modulators of neurotransmission, including the mechanism by which drugs can modulate the frequency and severity of epileptic seizures.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- The Departments of Medicine and Neurology, The Royal Melbourne Hospital, The Melbourne Brain Centre, The University of Melbourne, Parkville, Victoria, Australia
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Bialer M, Johannessen SI, Levy RH, Perucca E, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Eleventh Eilat Conference (EILAT XI). Epilepsy Res 2013; 103:2-30. [DOI: 10.1016/j.eplepsyres.2012.10.001] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 10/08/2012] [Indexed: 12/20/2022]
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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] [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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Galanin transgenic mice with elevated circulating galanin levels alleviate demyelination in a cuprizone-induced MS mouse model. PLoS One 2012; 7:e33901. [PMID: 22442732 PMCID: PMC3307774 DOI: 10.1371/journal.pone.0033901] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 02/19/2012] [Indexed: 01/15/2023] Open
Abstract
Multiple Sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system (CNS) with a presumed autoimmune etiology. Approved treatments for MS are immunoregulatory and are able to reduce the inflammatory components of the disease. However, these treatments do not suppress progressive clinical disability. Approaches that directly protect myelin-producing oligodendrocytes and enhance remyelination are likely to improve long-term outcomes and reduce the rate of axonal damage. Galanin (GAL) is a bioactive neuropeptide that is widely distributed throughout the nervous system and has diverse neuromodulatory effects. In this study, using the cuprizone (CPZ) demyelination model of MS, we demonstrate that GAL has pronounced neuroprotective effects with respect to demyelination and remyelination. Using our GAL transgenic mouse (GAL-Tg), we identified a novel attenuation of OLs against CPZ induced demyelination, which was exerted independently of progenitor cells. Alleviation of myelin breakdown in the GAL-Tg mice was observed to be significant. Furthermore, we observed changes in the expression of the GAL receptor GalR1 during the demyelination and remyelination processes. Our data strongly indicate that GAL has the capacity to influence the outcome of primary insults that directly target OLs, as opposed to cases where immune activation is the primary pathogenic event. Taken together, these results suggest that GAL is a promising next-generation target for the treatment of MS.
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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] [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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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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Sagi VN, Liu T, Lu X, Bartfai T, Roberts E. Synthesis and biological evaluation of novel pyrimidine derivatives as sub-micromolar affinity ligands of GalR2. Bioorg Med Chem Lett 2011; 21:7210-5. [PMID: 22018787 DOI: 10.1016/j.bmcl.2011.09.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 09/07/2011] [Accepted: 09/12/2011] [Indexed: 01/03/2023]
Abstract
GalR1 and GalR2 represent unique pharmacological targets for treatment of seizures and epilepsy. A novel series of 2,4,6-triaminopyrimidine derivatives were synthesized and found to have sub-micromolar affinity for GalR2. Optimization of a series of 2,4,6-triaminopyrimidines led to the discovery of several analogs with IC50 values ranging from 0.3 to 1 μM.
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Affiliation(s)
- Vasudeva Naidu Sagi
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, United States
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47
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Le Maître TW, Xia S, Le Maitre E, Dun XP, Lu J, Theodorsson E, Ogren SO, Hökfelt T, Xu ZQD. Galanin receptor 2 overexpressing mice display an antidepressive-like phenotype: possible involvement of the subiculum. Neuroscience 2011; 190:270-88. [PMID: 21672612 DOI: 10.1016/j.neuroscience.2011.05.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 04/21/2011] [Accepted: 05/04/2011] [Indexed: 01/13/2023]
Abstract
The behavioral phenotype of a transgenic mouse overexpressing a galanin receptor 2 (GalR2)-enhanced, green fluorescent protein (EGFP)-construct under the platelet-derived growth factor-B promoter, and of controls, was assessed in various behavioral tests, such as the Porsolt forced swim test, as well as the open field, elevated plus maze and passive avoidance tests. In addition, the distribution of GalR2-EGFP expressing cell bodies and processes was studied in the brain of these mice using histochemical methods. Three age groups of the transgenic mice demonstrated decreased levels of immobility in the forced swim test, indicative of antidepressive-like behavior and/or increased stress resistance. Anxiety-like behaviors, measured in two different tests, did not differ between the GalR2-overexpressing and the wild-type mice, nor did motor activity levels, emotional learning or memory behaviors. High levels of GalR2 mRNA and protein expression were observed in the presubiculum, subiculum, cingulate cortex, retrosplenial granular and agranular cortices, subregions of prefrontal cortex, and the olfactory bulb, regions which are directly or indirectly implicated in depression-like behavior. These results may contribute to the understanding of the pathophysiology of major depressive disorder and the role of GalR2 in the regulation of mood, and suggest a potential therapeutic effect by targeting the GalR2 for treatment of depressive disorders.
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Affiliation(s)
- T Wardi Le Maître
- Department of Neuroscience, Karolinska Institutet, Retzius Väg 8, S-17177 Stockholm, Sweden.
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Fornai F, Ruffoli R, Giorgi FS, Paparelli A. The role of locus coeruleus in the antiepileptic activity induced by vagus nerve stimulation. Eur J Neurosci 2011; 33:2169-78. [DOI: 10.1111/j.1460-9568.2011.07707.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Neuroanatomical localization and physiological properties of galanin suggest that the peptide may be involved in the regulation of seizures. Indeed, administration of galanin receptor agonists into brain areas pertinent to the initiation and propagation of epileptic activity attenuated seizure responses under conditions of animal models of epilepsy; pharmacological blocking of galanin receptors exerted proconvulsant effects. Functional deletion of both galanin and galanin type 1 receptor genes produced transgenic mice with either spontaneous seizure phenotype, or with enhanced susceptibility to seizure stimuli. At the same time, overexpression of galanin in seizure pathways, using both transgenic and virus vector transfection techniques, hindered the epileptic process. Galanin exerts anticonvulsant effects through both type 1 and type 2 receptors, with distinct downstream signaling cascades. Several synthetic agonists of galanin receptors with optimized bioavailability have been synthesized and inhibited experimental seizures upon systemic administration, thus opening an opportunity for the development of galanin-based antiepileptic drugs.
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Robertson CR, Flynn SP, White HS, Bulaj G. Anticonvulsant neuropeptides as drug leads for neurological diseases. Nat Prod Rep 2011; 28:741-62. [PMID: 21340067 DOI: 10.1039/c0np00048e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Anticonvulsant neuropeptides are best known for their ability to suppress seizures and modulate pain pathways. Galanin, neuropeptide Y, somatostatin, neurotensin, dynorphin, among others, have been validated as potential first-in-class anti-epileptic or/and analgesic compounds in animal models of epilepsy and pain, but their therapeutic potential extends to other neurological indications, including neurodegenerative and psychatric disorders. Disease-modifying properties of neuropeptides make them even more attractive templates for developing new-generation neurotherapeutics. Arguably, efforts to transform this class of neuropeptides into drugs have been limited compared to those for other bioactive peptides. Key challenges in developing neuropeptide-based anticonvulsants are: to engineer optimal receptor-subtype selectivity, to improve metabolic stability and to enhance their bioavailability, including penetration across the blood–brain barrier (BBB). Here, we summarize advances toward developing systemically active and CNS-penetrant neuropeptide analogs. Two main objectives of this review are: (1) to provide an overview of structural and pharmacological properties for selected anticonvulsant neuropeptides and their analogs and (2) to encourage broader efforts to convert these endogenous natural products into drug leads for pain, epilepsy and other neurological diseases.
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Affiliation(s)
- Charles R Robertson
- College of Pharmacy, Department of Medicinal Chemistry, 421 Wakara Way, STE. 360 Salt Lake City, UT 84108, USA
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