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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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Cheng H, Wang Y, Chen J, Chen Z. The piriform cortex in epilepsy: What we learn from the kindling model. Exp Neurol 2020; 324:113137. [DOI: 10.1016/j.expneurol.2019.113137] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/14/2022]
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Devilbiss DM. Consequences of tuning network function by tonic and phasic locus coeruleus output and stress: Regulating detection and discrimination of peripheral stimuli. Brain Res 2018; 1709:16-27. [PMID: 29908165 DOI: 10.1016/j.brainres.2018.06.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/23/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022]
Abstract
Flexible and adaptive behaviors have evolved with increasing complexity and numbers of neuromodulator systems. The neuromodulatory locus coeruleus-norepinephrine (LC-NE) system is central to regulating cognitive function in a behaviorally-relevant and arousal-dependent manner. Through its nearly ubiquitous efferent projections, the LC-NE system acts to modulate neuron function on a cell-by-cell basis and exert a spectrum of actions across different brain regions to optimize target circuit function. As LC neuron activity, NE signaling, and arousal level increases, cognitive performance improves over an inverted-U shaped curve. Additionally, LC neurons burst phasically in relation to novel or salient sensory stimuli and top-down decision- or response-related processes. Together, the variety of LC activity patterns and complex actions of the LC-NE system indicate that the LC-NE system may dynamically regulate the function of target neural circuits. The manner in which neural networks encode, represent, and perform neurocomputations continue to be revealed. This has improved our ability to understand the optimization of neural circuits by NE and generation of flexible and adaptive goal-directed behaviors. In this review, the rat vibrissa somatosensory system is explored as a model neural circuit to bridge known modulatory actions of NE and changes in cognitive function. It is argued that fluid transitions between neural computational states reflect the ability of this sensory system to shift between two principal functions: detection of novel or salient sensory information and detailed descriptions of sensory information. Such flexibility in circuit function is likely critical for producing context-appropriate sensory signal processing. Nonetheless, many challenges remain including providing a causal link between NE mediated changes in sensory neural coding and perceptual changes, as well as extending these principles to higher cognitive functions including behavioral flexibility and decision making.
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Affiliation(s)
- David M Devilbiss
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084, United States.
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Galanin contributes to monoaminergic dysfunction and to dependent neurobehavioral comorbidities of epilepsy. Exp Neurol 2016; 289:64-72. [PMID: 28013000 DOI: 10.1016/j.expneurol.2016.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/23/2016] [Accepted: 12/20/2016] [Indexed: 01/01/2023]
Abstract
Status epilepticus (SE) in rats, along with chronic epilepsy, leads to the development of behavioral impairments resembling depressive disorder and/or attention deficit/hyperactivity disorder (ADHD), thus reflecting respective comorbidities in epilepsy patients. Suppressed neurotransmitter tone in the raphe nucleus (RN)-prefrontal cortex (PFC) serotonergic pathway and in the locus coeruleus (LC)-PFC noradrenergic pathway underlies depressive- and impulsive-like behavioral deficits respectively. We examined possible mechanisms leading to the monoamine dysfunction in brainstem efferents, namely modulatory effects of the neuropeptide galanin on serotonin (5-HT) and norepinephrine (NE) signaling. SE was induced in young adult male Wistar rats by LiCl and pilocarpine. Epileptic rats were categorized vis-à-vis behavioral deficits as not impaired, "depressed" and "impulsive". Depressive- and impulsive-like behaviors were examined in the forced swimming test (FST). The strength of serotonergic transmission in RN-PFC and of noradrenergic transmission in LC-PFC was analyzed using in vivo fast scan cyclic voltammetry. Galanin receptor type 1 (GalR1)/type 2 (GalR2) antagonist M40, and a preferential GalR2 antagonist M871 were administered over 3days locally into either RN or LC by means of ALZET osmotic minipumps connected to locally implanted infusion cannulas. Intra-RN injection of M40 improved serotonergic tone and depressive-like behavior in epileptic "depressed" rats. Intra-LC injection of M40 improved noradrenergic tone and impulsive-like behavior in epileptic "impulsive" rats. The effects of M40 were only observed in impaired subjects. The treatment did not modify neurotransmission and behavior in naïve and epileptic not impaired rats; in "depressed" rats the effects were limited to serotonergic transmission and immobility, while in "impulsive" rats - to noradrenergic transmission and struggling behavior. Intra-RN administration of M871 exacerbated depressive-like behavior, but had no effects on any other of the examined parameters in any category of animals. These findings suggest that endogenous galanin, acting through GalR1 may be involved in the pathophysiology of epilepsy-associated depression and ADHD via inhibiting RN-PFC serotonergic and LC-PFC noradrenergic transmissions respectively.
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Sprissler RS, Wagnon JL, Bunton-Stasyshyn RK, Meisler MH, Hammer MF. Altered gene expression profile in a mouse model of SCN8A encephalopathy. Exp Neurol 2016; 288:134-141. [PMID: 27836728 DOI: 10.1016/j.expneurol.2016.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/06/2016] [Accepted: 11/03/2016] [Indexed: 02/07/2023]
Abstract
SCN8A encephalopathy is a severe, early-onset epilepsy disorder resulting from de novo gain-of-function mutations in the voltage-gated sodium channel Nav1.6. To identify the effects of this disorder on mRNA expression, RNA-seq was performed on brain tissue from a knock-in mouse expressing the patient mutation p.Asn1768Asp (N1768D). RNA was isolated from forebrain, cerebellum, and brainstem both before and after seizure onset, and from age-matched wildtype littermates. Altered transcript profiles were observed only in forebrain and only after seizures. The abundance of 50 transcripts increased more than 3-fold and 15 transcripts decreased more than 3-fold after seizures. The elevated transcripts included two anti-convulsant neuropeptides and more than a dozen genes involved in reactive astrocytosis and response to neuronal damage. There was no change in the level of transcripts encoding other voltage-gated sodium, potassium or calcium channels. Reactive astrocytosis was observed in the hippocampus of mutant mice after seizures. There is considerable overlap between the genes affected in this genetic model of epilepsy and those altered by chemically induced seizures, traumatic brain injury, ischemia, and inflammation. The data support the view that gain-of-function mutations of SCN8A lead to pathogenic alterations in brain function contributing to encephalopathy.
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Affiliation(s)
- Ryan S Sprissler
- ARL Division of Biotechnology, University of Arizona, Tucson, AZ 85721, USA
| | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Miriam H Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Michael F Hammer
- ARL Division of Biotechnology, University of Arizona, Tucson, AZ 85721, USA; Department of Neurology, University of Arizona, Tucson, AZ 85721, USA.
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Flynn SP, White HS. Regulation of glucose and insulin release following acute and repeated treatment with the synthetic galanin analog NAX-5055. Neuropeptides 2015; 50:35-42. [PMID: 25690510 PMCID: PMC4402648 DOI: 10.1016/j.npep.2015.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 11/19/2014] [Accepted: 01/05/2015] [Indexed: 12/12/2022]
Abstract
The neuropeptide galanin is widely expressed in both the central and peripheral nervous systems. However there is limited understanding of how individual galanin receptor (GalR1, 2, and 3) subtypes mediate the physiological activity of galanin in vivo. To address this issue we utilized NAX-5055, a systemically available, metabolically stable galanin analog. NAX-5055 displays a preference for GalR1 receptors and possesses potent anticonvulsant activity in vivo, suggesting that NAX-5055 engages central galanin receptors. To determine if NAX-5055 also modulates the activity of peripheral galanin receptors, we evaluated the effect of NAX-5055 on blood glucose and insulin levels in mice. Acute and repeated (once daily for four days) systemic administration of NAX-5055 (4 mg/kg) significantly increased blood glucose levels compared to vehicle treated mice. However, a hyperglycemic response was not observed following systemic administration of NAX-805-1, a scrambled analog of NAX-5055, with critical receptor binding residues, Trp(2) and Tyr(9), reversed. These results suggest that chemical modifications independent of the galanin backbone of NAX-5055 are not responsible for the hyperglycemic response. The effect of NAX-5055 on glucose homeostasis was further evaluated with a glucose tolerance test (GTT). Mice administered either acute or repeated (once daily for four days) injections of NAX-5055 (4 mg/kg) displayed impaired glucose handling and reduced insulin response to an acute glucose (1g/kg) challenge. Here we have shown that systemic administration of a centrally active GalR1-preferring galanin analog produces acute hyperglycemia and an inhibition of insulin release in vivo and that these effects are not attenuated with repeated administration. NAX-5055 thus provides a new pharmacological tool to further the understanding of function of both central and peripheral GalR1 receptors in vivo.
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Affiliation(s)
- Sean P Flynn
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT 84108, USA; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84108, USA
| | - H Steve White
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT 84108, USA; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84108, USA.
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Yang H, Wu J, Guo R, Peng Y, Zheng W, Liu D, Song Z. Glycolysis in energy metabolism during seizures. Neural Regen Res 2014; 8:1316-26. [PMID: 25206426 PMCID: PMC4107649 DOI: 10.3969/j.issn.1673-5374.2013.14.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 03/27/2013] [Indexed: 01/23/2023] Open
Abstract
Studies have shown that glycolysis increases during seizures, and that the glycolytic metabolite lactic acid can be used as an energy source. However, how lactic acid provides energy for seizures and how it can participate in the termination of seizures remains unclear. We reviewed possible mechanisms of glycolysis involved in seizure onset. Results showed that lactic acid was involved in seizure onset and provided energy at early stages. As seizures progress, lactic acid reduces the pH of tissue and induces metabolic acidosis, which terminates the seizure. The specific mechanism of lactic acid-induced acidosis involves several aspects, which include lactic acid-induced inhibition of the glycolytic enzyme 6-diphosphate kinase-1, inhibition of the N-methyl-D-aspartate receptor, activation of the acid-sensitive 1A ion channel, strengthening of the receptive mechanism of the inhibitory neurotransmitter γ-minobutyric acid, and changes in the intra- and extracellular environment.
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Affiliation(s)
- Heng Yang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Jiongxing Wu
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Ren Guo
- Department of Pharmacy, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Yufen Peng
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Wen Zheng
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Ding Liu
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Zhi Song
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
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Nikitidou L, Torp M, Fjord-Larsen L, Kusk P, Wahlberg LU, Kokaia M. Encapsulated galanin-producing cells attenuate focal epileptic seizures in the hippocampus. Epilepsia 2013; 55:167-74. [DOI: 10.1111/epi.12470] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Litsa Nikitidou
- Experimental Epilepsy Group; Wallenberg Neuroscience Center; BMC A-11; Lund University Hospital; Lund Sweden
| | | | | | | | | | - Mérab Kokaia
- Experimental Epilepsy Group; Wallenberg Neuroscience Center; BMC A-11; Lund University Hospital; Lund Sweden
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Corticotropin-releasing factor acting at the locus coeruleus disrupts thalamic and cortical sensory-evoked responses. Neuropsychopharmacology 2012; 37:2020-30. [PMID: 22510725 PMCID: PMC3398725 DOI: 10.1038/npp.2012.50] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Stress and stress-related psychiatric disorders, including post-traumatic stress disorder, are associated with disruptions in sensory information processing. The neuropeptide, corticotropin-releasing factor (CRF), coordinates the physiological and behavioral responses to stress, in part, by activating the locus coeruleus-norepinephrine (LC-NE) projection system. Although the LC-NE system is an important modulator of sensory information processing, to date, the consequences of CRF activation of this system on sensory signal processing are poorly understood. The current study examined the dose-dependent actions of CRF at the LC on spontaneous and sensory-evoked discharge of neurons within the thalamus and cortex of the vibrissa somatosensory system in the awake, freely moving rat. Peri-LC infusions of CRF resulted in a dose-dependent suppression of sensory-evoked discharge in ventral posterior medial thalamic and barrel field cortical neurons. A concurrent increase in spontaneous activity was observed. This latter action is generally not found with iontophoretic application of NE to target neurons or stimulation of the LC-NE pathway. Net decreases in signal-to-noise of sensory-evoked responses within both regions suggest that under conditions associated with CRF release at the LC, including stress, the transfer of afferent information within sensory systems is impaired. Acutely, a suppression of certain types of sensory information may represent an adaptive response to an immediate unexpected stressor. Persistence of such effects could contribute to abnormalities of information processing seen in sensorimotor gating associated with stress and stress-related psychopathology.
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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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Devilbiss DM, Waterhouse BD. Phasic and tonic patterns of locus coeruleus output differentially modulate sensory network function in the awake rat. J Neurophysiol 2010; 105:69-87. [PMID: 20980542 DOI: 10.1152/jn.00445.2010] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neurons of the nucleus locus coeruleus (LC) discharge with phasic bursts of activity superimposed on highly regular tonic discharge rates. Phasic bursts are elicited by bottom-up input mechanisms involving novel/salient sensory stimuli and top-down decision making processes; whereas tonic rates largely fluctuate according to arousal levels and behavioral states. Although it is generally believed that these two modes of activity differentially modulate information processing in LC targets, the unique role of phasic versus tonic LC output on signal processing in cells, circuits, and neural networks of waking animals is not well understood. In the current study, simultaneous recordings of individual neurons within ventral posterior medial thalamus and barrel field cortex of conscious rats provided evidence that each mode of LC output produces a unique modulatory impact on single neuron responsiveness to sensory-driven synaptic input and representations of sensory information across ensembles of simultaneously recorded cells. Each mode of LC activation specifically modulated the relationship between sensory-stimulus intensity and the subsequent responses of individual neurons and neural ensembles. Overall these results indicate that phasic versus tonic modes of LC discharge exert fundamentally different modulatory effects on target neuronal circuits within the rodent trigeminal somatosensory system. As such, each mode of LC output may differentially influence signal processing as a means of optimizing behaviorally relevant neural computations within this sensory network. Likely the ability of the LC system to differentially regulate neural responses and local circuit operations according to behavioral demands extends to other brain regions including those involved in higher cognitive functions.
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Affiliation(s)
- David M Devilbiss
- Department of Psychology, University of Wisconsin, Madison, Wisconsin 53706, USA.
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Boison D. Cell and gene therapies for refractory epilepsy. Curr Neuropharmacol 2010; 5:115-25. [PMID: 18615179 DOI: 10.2174/157015907780866938] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 03/07/2007] [Accepted: 03/08/2007] [Indexed: 12/20/2022] Open
Abstract
Despite recent advances in the development of antiepileptic drugs, refractory epilepsy remains a major clinical problem affecting up to 35% of patients with partial epilepsy. Currently, there are few therapies that affect the underlying disease process. Therefore, novel therapeutic concepts are urgently needed. The recent development of experimental cell and gene therapies may offer several advantages compared to conventional systemic pharmacotherapy: (i) Specificity to underlying pathogenetic mechanisms by rational design; (ii) specificity to epileptogenic networks by focal delivery; and (iii) avoidance of side effects. A number of naturally occurring brain substances, such as GABA, adenosine, and the neuropeptides galanin and neuropeptide Y, may function as endogenous anticonvulsants and, in addition, may interact with the process of epileptogenesis. Unfortunately, the systemic application of these compounds is compromised by limited bioavailability, poor penetration of the blood-brain barrier, or the widespread systemic distribution of their respective receptors. Therefore, in recent years a new field of cell and gene-based neuropharmacology has emerged, aimed at either delivering endogenous anticonvulsant compounds by focal intracerebral transplantation of bioengineered cells (ex vivo gene therapy), or by inducing epileptogenic brain areas to produce these compounds in situ (in vivo gene therapy). In this review, recent efforts to develop GABA-, adenosine-, galanin-, and neuropeptide Y- based cell and gene therapies are discussed. The neurochemical rationales for using these compounds are discussed, the advantages of focal applications are highlighted and preclinical cell transplantation and gene therapy studies are critically evaluated. Although many promising data have been generated recently, potential problems, such as long-term therapeutic efficacy, long-term safety, and efficacy in clinically relevant animal models, need to be addressed before clinical applications can be contemplated.
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Affiliation(s)
- Detlev Boison
- RS Dow Neurobiology Laboratories, Legacy Research, Portland, OR 97232, USA.
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Mitsukawa K, Lu X, Bartfai T. Galanin, galanin receptors, and drug targets. EXPERIENTIA SUPPLEMENTUM (2012) 2010; 102:7-23. [PMID: 21299058 DOI: 10.1007/978-3-0346-0228-0_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Galanin, a neuropeptide widely expressed in the central and peripheral nervous systems and in the endocrine system, has been shown to regulate numerous physiological and pathological processes through interactions with three G-protein-coupled receptors, GalR1 through GalR3. Over the past decade, some of the receptor subtype-specific effects have been elucidated through pharmacological studies using subtype selective ligands, as well as through molecular approaches involving knockout animals. In this chapter, we summarize the current data which constitute the basis of targeting GalR1, GalR2, and GalR3 for the treatment of various human diseases and pathological conditions, including seizure, Alzheimer's disease, mood disorders, anxiety, alcohol intake in addiction, metabolic diseases, pain and solid tumors.
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Affiliation(s)
- K Mitsukawa
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Jones M, Perumal P, Vrontakis M. Presence of Galanin-Like Immunoreactivity in Mesenchymal and Neural Crest Origin Tissues During Embryonic Development in the Mouse. Anat Rec (Hoboken) 2009; 292:481-7. [DOI: 10.1002/ar.20850] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bulaj G, Green BR, Lee HK, Robertson CR, White K, Zhang L, Sochanska M, Flynn SP, Scholl EA, Pruess TH, Smith MD, White HS. Design, Synthesis, and Characterization of High-Affinity, Systemically-Active Galanin Analogues with Potent Anticonvulsant Activities. J Med Chem 2008; 51:8038-47. [DOI: 10.1021/jm801088x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Grzegorz Bulaj
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Brad R. Green
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Hee-Kyoung Lee
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Charles R. Robertson
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Karen White
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Liuyin Zhang
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Marianna Sochanska
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Sean P. Flynn
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Erika Adkins Scholl
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Timothy H. Pruess
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - Misty D. Smith
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
| | - H. Steve White
- Department of Medicinal Chemistry, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah 84108
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Kanter-Schlifke I, Toft Sørensen A, Ledri M, Kuteeva E, Hökfelt T, Kokaia M. Galanin gene transfer curtails generalized seizures in kindled rats without altering hippocampal synaptic plasticity. Neuroscience 2007; 150:984-92. [DOI: 10.1016/j.neuroscience.2007.09.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 09/10/2007] [Accepted: 09/28/2007] [Indexed: 11/26/2022]
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Abstract
The ketogenic diet (KD) is a broadly effective treatment for medically refractory epilepsy. Despite nearly a century of use, the mechanisms underlying its clinical efficacy remain unknown. In this review, we present one intersecting view of how the KD may exert its anticonvulsant activity against the backdrop of several seemingly disparate mechanistic theories. We summarize key insights gleaned from experimental and clinical studies of the KD, and focus particular attention on the role that ketone bodies, fatty acids, and limited glucose may play in seizure control. Chronic ketosis is anticipated to modify the tricarboxcylic acid cycle to increase GABA synthesis in brain, limit reactive oxygen species (ROS) generation, and boost energy production in brain tissue. Among several direct neuro-inhibitory actions, polyunsaturated fatty acids increased after KD induce the expression of neuronal uncoupling proteins (UCPs), a collective up-regulation of numerous energy metabolism genes, and mitochondrial biogenesis. These effects further limit ROS generation and increase energy production. As a result of limited glucose and enhanced oxidative phosphorylation, reduced glycolytic flux is hypothesized to activate metabolic K(ATP) channels and hyperpolarize neurons and/or glia. Although it is unlikely that a single mechanism, however well substantiated, will explain all of the diet's clinical benefits, these diverse, coordinated changes seem poised to stabilize synaptic function and increase the resistance to seizures throughout the brain.
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Affiliation(s)
- Kristopher J Bough
- Center for Drug Evaluation and Research, Food and Drug Administration, Rockville, Maryland 20855, USA.
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