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Aydogan Avşar P, Akkuş M. ZO-1 Serum Levels as a Potential Biomarker for Psychotic Disorder. Clin Neuropharmacol 2024; 47:67-71. [PMID: 38743599 DOI: 10.1097/wnf.0000000000000590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
OBJECTIVE There are limited studies in the literature on the relationship between intestinal and blood-brain barrier permeability and the etiology of schizophrenia. We hypothesized that the difference in serum ZO-1 levels in patients with schizophrenia may affect the severity of the disease. The aim of this study was to investigate the role of changes in serum ZO-1 concentrations in the etiopathogenesis of patients with schizophrenia. METHODS A total of 46 patients, 34 with schizophrenia, 12 with a first psychotic attack, and 37 healthy controls, were included in the study. Symptom severity was determined by applying the Positive and Negative Syndrome Scale and the Clinical Global Impression-Severity Scale. Serum ZO-1 levels were measured from venous blood samples. RESULTS Serum ZO-1 levels were higher in patients with psychotic disorder compared to healthy controls. There was no statistically significant difference between the groups in the first psychotic attack group and the schizophrenia patients. There was a statistically significant positive correlation between serum ZO-1 levels and Positive and Negative Syndrome Scale positive symptom score. CONCLUSIONS These findings regarding ZO-1 levels suggest that dysregulation of the blood-brain barrier in psychotic disorder may play a role in the etiology of the disorder.
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Affiliation(s)
- Pinar Aydogan Avşar
- Department of Child and Adolescent Psychiatry, Alanya Alaaddin Keykubat University Training and Research Hospital, Alanya, Turkey
| | - Merve Akkuş
- Department of Psychiatry, Kütahya Health Sciences University, Evliya Celebi Education and Research Hospital, Kütahya, Turkey
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2
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Parent HH, Niswender CM. Therapeutic Potential for Metabotropic Glutamate Receptor 7 Modulators in Cognitive Disorders. Mol Pharmacol 2024; 105:348-358. [PMID: 38423750 PMCID: PMC11026152 DOI: 10.1124/molpharm.124.000874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/05/2024] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
Metabotropic glutamate receptor 7 (mGlu7) is the most highly conserved and abundantly expressed mGlu receptor in the human brain. The presynaptic localization of mGlu7, coupled with its low affinity for its endogenous agonist, glutamate, are features that contribute to the receptor's role in modulating neuronal excitation and inhibition patterns, including long-term potentiation, in various brain regions. These characteristics suggest that mGlu7 modulation may serve as a novel therapeutic strategy in disorders of cognitive dysfunction, including neurodevelopmental disorders that cause impairments in learning, memory, and attention. Primary mutations in the GRM7 gene have recently been identified as novel causes of neurodevelopmental disorders, and these patients exhibit profound intellectual and cognitive disability. Pharmacological tools, such as agonists, antagonists, and allosteric modulators, have been the mainstay for targeting mGlu7 in its endogenous homodimeric form to probe effects of its function and modulation in disease models. However, recent research has identified diversity in dimerization, as well as trans-synaptic interacting proteins, that also play a role in mGlu7 signaling and pharmacological properties. These novel findings represent exciting opportunities in the field of mGlu receptor drug discovery and highlight the importance of further understanding the functions of mGlu7 in complex neurologic conditions at both the molecular and physiologic levels. SIGNIFICANCE STATEMENT: Proper expression and function of mGlu7 is essential for learning, attention, and memory formation at the molecular level within neural circuits. The pharmacological targeting of mGlu7 is undergoing a paradigm shift by incorporating an understanding of receptor interaction with other cis- and trans- acting synaptic proteins, as well as various intracellular signaling pathways. Based upon these new findings, mGlu7's potential as a drug target in the treatment of cognitive disorders and learning impairments is primed for exploration.
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Affiliation(s)
- Harrison H Parent
- Department of Pharmacology (H.H.P., C.M.N.), Warren Center for Neuroscience Drug Discovery (H.H.P., C.M.N.), Vanderbilt Brain Institute (C.M.N.), and Vanderbilt Institute for Chemical Biology (C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N.)
| | - Colleen M Niswender
- Department of Pharmacology (H.H.P., C.M.N.), Warren Center for Neuroscience Drug Discovery (H.H.P., C.M.N.), Vanderbilt Brain Institute (C.M.N.), and Vanderbilt Institute for Chemical Biology (C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N.)
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3
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Zhao X, He Z, Li Y, Yang X, Li B. Atypical absence seizures and gene variants: A gene-based review of etiology, electro-clinical features, and associated epilepsy syndrome. Epilepsy Behav 2024; 151:109636. [PMID: 38232560 DOI: 10.1016/j.yebeh.2024.109636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/01/2024] [Accepted: 01/05/2024] [Indexed: 01/19/2024]
Abstract
Atypical absence seizures are generalized non-convulsive seizures that often occur in children with cognitive impairment. They are common in refractory epilepsy and have been recognized as one of the hallmarks of developmental epileptic encephalopathies. Notably, pathogenic variants associated with AAS, such as GABRG2, GABRG3, SLC6A1, CACNB4, SCN8A, and SYNGAP1, are also linked to developmental epileptic encephalopathies. Atypical absences differ from typical absences in that they are frequently drug-resistant and the prognosis is dependent on the etiology or related epileptic syndromes. To improve clinicians' understanding of atypical absences and provide novel perspectives for clinical treatment, we have reviewed the electro-clinical characteristics, etiologies, treatment, and prognosis of atypical absences, with a focus on the etiology of advancements in gene variants, shedding light on potential avenues for improved clinical management.
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Affiliation(s)
| | - Zimeng He
- Shandong University, Jinan, Shandong, China
| | - Yumei Li
- Shandong University, Jinan, Shandong, China
| | - Xiaofan Yang
- Shandong University, Jinan, Shandong, China; Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, China.
| | - Baomin Li
- Shandong University, Jinan, Shandong, China; Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, China.
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4
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Januel L, Chatron N, Rivier-Ringenbach C, Cabet S, Labalme A, Sahin Y, Darvish H, Kruer M, Bakhtiari S, Sanlaville D, de Sainte Agathe JM, Lesca G. GRM7-related disorder: five additional patients from three independent families and review of the literature. Eur J Med Genet 2024; 67:104893. [PMID: 38070825 DOI: 10.1016/j.ejmg.2023.104893] [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: 06/07/2023] [Revised: 10/22/2023] [Accepted: 12/03/2023] [Indexed: 12/19/2023]
Abstract
Developmental and epileptic encephalopathies (DEEs) refer to a group of severe epileptic syndromes characterized by seizures as well as a developmental delay which can be a consequence of the underlying etiology and/or the epileptic encephalopathy. The genes responsible for DEEs are numerous and their number is increasing since the availability of Next-Generation Sequencing. Pathogenic variants in GRM7, encoding the metabotropic glutamate receptor 7, were recently shown as a cause of a severe DEE with autosomal recessive inheritance. To date, only ten patients have been reported in the literature, generally with severe phenotypes including early-onset epilepsy, microcephaly, brain anomalies, and spasticity. We report here 5 patients from 3 independent families with biallelic variants in the GRM7 gene. We review the literature and provide further elements for the understanding of the genotype-phenotype correlation of this rare syndrome.
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Affiliation(s)
- Louis Januel
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Génétique, Bron, France.
| | - Nicolas Chatron
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Génétique, Bron, France; Institut NeuroMyoGene PNMG, CNRS UMR5310, INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | | | - Sara Cabet
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Radiologie, Bron, France
| | - Audrey Labalme
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Génétique, Bron, France
| | | | - Hossein Darvish
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Michael Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Damien Sanlaville
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Génétique, Bron, France; Institut NeuroMyoGene PNMG, CNRS UMR5310, INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | | | - Gaetan Lesca
- Hospices Civils de Lyon, Groupe Hospitalier Est, Service de Génétique, Bron, France; Institut NeuroMyoGene PNMG, CNRS UMR5310, INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
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5
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Lindquist BE, Timbie C, Voskobiynyk Y, Paz JT. Thalamocortical circuits in generalized epilepsy: Pathophysiologic mechanisms and therapeutic targets. Neurobiol Dis 2023; 181:106094. [PMID: 36990364 PMCID: PMC10192143 DOI: 10.1016/j.nbd.2023.106094] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/02/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023] Open
Abstract
Generalized epilepsy affects 24 million people globally; at least 25% of cases remain medically refractory. The thalamus, with widespread connections throughout the brain, plays a critical role in generalized epilepsy. The intrinsic properties of thalamic neurons and the synaptic connections between populations of neurons in the nucleus reticularis thalami and thalamocortical relay nuclei help generate different firing patterns that influence brain states. In particular, transitions from tonic firing to highly synchronized burst firing mode in thalamic neurons can cause seizures that rapidly generalize and cause altered awareness and unconsciousness. Here, we review the most recent advances in our understanding of how thalamic activity is regulated and discuss the gaps in our understanding of the mechanisms of generalized epilepsy syndromes. Elucidating the role of the thalamus in generalized epilepsy syndromes may lead to new opportunities to better treat pharmaco-resistant generalized epilepsy by thalamic modulation and dietary therapy.
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Affiliation(s)
- Britta E Lindquist
- UCSF Department of Neurology, Division of Neurocritical Care, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Clare Timbie
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America; Kavli Institute for Fundamental Neuroscience, UCSF, United States of America.
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Tuduri P, Bouquier N, Girard B, Moutin E, Thouaye M, Perroy J, Bertaso F, Ster J. Modulation of Hippocampal Network Oscillation by PICK1-Dependent Cell Surface Expression of mGlu3 Receptors. J Neurosci 2022; 42:8897-8911. [PMID: 36202617 PMCID: PMC9698693 DOI: 10.1523/jneurosci.0063-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 09/27/2022] [Accepted: 09/30/2022] [Indexed: 12/29/2022] Open
Abstract
Metabotropic glutamate receptor Type 3 (mGlu3) controls the sleep/wake architecture, which plays a role in the glutamatergic pathophysiology of schizophrenia. Interestingly, mGlu3 receptor expression is decreased in the brain of schizophrenic patients. However, little is known about the molecular mechanisms regulating mGlu3 receptors at the cell membrane. Subcellular receptor localization is strongly dependent on protein-protein interactions. Here we show that mGlu3 interacts with PICK1 and that this scaffolding protein is important for mGlu3 surface expression and function in hippocampal primary cultures. Disruption of their interaction via an mGlu3 C-terminal mimicking peptide or an inhibitor of the PDZ domain of PICK1 altered the functional expression of mGlu3 receptors in neurons. We next investigated the impact of disrupting the mGlu3-PICK1 interaction on hippocampal theta oscillations in vitro and in vivo in WT male mice. We found a decreased frequency of theta oscillations in organotypic hippocampal slices, similar to what was previously observed in mGlu3 KO mice. In addition, hippocampal theta power was reduced during rapid eye movement sleep, non-rapid eye movement (NREM) sleep, and wake states after intraventricular administration of the mGlu3 C-terminal mimicking peptide. Targeting the mGlu3-PICK1 complex could thus be relevant to the pathophysiology of schizophrenia.SIGNIFICANCE STATEMENT Dysregulation of the glutamatergic system might play a role in the pathophysiology of schizophrenia. Metabotropic glutamate receptors Type 3 (mGlu3) have been proposed as potential targets for schizophrenia. Understanding the molecular mechanisms regulating mGlu3 receptor at the cell membrane is critical toward comprehending how their dysfunction contributes to the pathogenesis of schizophrenia. Here we describe that the binding of the signaling and scaffolding protein PICK1 to mGlu3 receptors is important for their localization and physiological functions. The identification of new proteins that associate specifically to mGlu3 receptors will advance our understanding of the regulatory mechanisms associated with their targeting and function and ultimately might provide new therapeutic strategies to counter these psychiatric conditions.
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Affiliation(s)
- Pola Tuduri
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Nathalie Bouquier
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Benoit Girard
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Enora Moutin
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Maxime Thouaye
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Julie Perroy
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Federica Bertaso
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
| | - Jeanne Ster
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34094, France
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Sørensen AT, Rombach J, Gether U, Madsen KL. The Scaffold Protein PICK1 as a Target in Chronic Pain. Cells 2022; 11:cells11081255. [PMID: 35455935 PMCID: PMC9031029 DOI: 10.3390/cells11081255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/23/2022] [Accepted: 03/30/2022] [Indexed: 02/05/2023] Open
Abstract
Well-tolerated and effective drugs for treating chronic pain conditions are urgently needed. Most chronic pain patients are not effectively relieved from their pain and suffer from debilitating drug side effects. This has not only drastic negative consequences for the patients’ quality of life, but also constitute an enormous burden on society. It is therefore of great interest to explore new potent targets for effective pain treatment with fewer side effects and without addiction liability. A critical component of chronic pain conditions is central sensitization, which involves the reorganization and strengthening of synaptic transmission within nociceptive pathways. Such changes are considered as maladaptive and depend on changes in the surface expression and signaling of AMPA-type glutamate receptors (AMPARs). The PDZ-domain scaffold protein PICK1 binds the AMPARs and has been suggested to play a key role in these maladaptive changes. In the present paper, we review the regulation of AMPARs by PICK1 and its relation to pain pathology. Moreover, we highlight other pain-relevant PICK1 interactions, and we evaluate various compounds that target PICK1 and have been successfully tested in pain models. Finally, we evaluate the potential on-target side effects of interfering with the action of PICK1 action in CNS and beyond. We conclude that PICK1 constitutes a valid drug target for the treatment of inflammatory and neuropathic pain conditions without the side effects and abuse liability associated with current pain medication.
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8
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Liu Y, Wang Y, Yang J, Xu T, Tan C, Zhang P, Liu Q, Chen Y. G-alpha interacting protein interacting protein, C terminus 1 regulates epileptogenesis by increasing the expression of metabotropic glutamate receptor 7. CNS Neurosci Ther 2021; 28:126-138. [PMID: 34676980 PMCID: PMC8673704 DOI: 10.1111/cns.13746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 12/31/2022] Open
Abstract
Aims It has been reported that the G‐alpha interacting protein (GAIP) interacting protein, C terminus 1 (GIPC1/GIPC) engages in vesicular trafficking, receptor transport and expression, and endocytosis. However, its role in epilepsy is unclear. Therefore, in this study, we aimed to explore the role of GIPC1 in epilepsy and its possible underlying mechanism. Methods The expression patterns of GIPC1 in patients with temporal lobe epilepsy (TLE) and in mice with kainic acid (KA)‐induced epilepsy were detected. Behavioral video monitoring and hippocampal local field potential (LFP) recordings were carried out to determine the role of GIPC1 in epileptogenesis after overexpression of GIPC1. Coimmunoprecipitation (Co‐IP) assay and high‐resolution immunofluorescence staining were conducted to investigate the relationship between GIPC1 and metabotropic glutamate receptor 7 (mGluR7). In addition, the expression of mGluR7 after overexpression of GIPC1 was measured, and behavioral video monitoring and LFP recordings after antagonism of mGluR7 were performed to explore the possible mechanism mediated by GIPC1. Results GIPC1 was downregulated in the brain tissues of patients with TLE and mice with KA‐induced epilepsy. After overexpression of GIPC1, prolonged latency period, decreased epileptic seizures and reduced seizure severity in behavioral analyses, and fewer and shorter abnormal brain discharges in LFP recordings of KA‐induced epileptic mice were observed. The result of the Co‐IP assay showed the interaction between GIPC1 and mGluR7, and the high‐resolution immunofluorescence staining also showed the colocalization of these two proteins. Additionally, along with GIPC1 overexpression, the total and cell membrane expression levels of mGluR7 were also increased. And after antagonism of mGluR7, increased epileptic seizures and aggravated seizure severity in behavioral analyses and more and longer abnormal brain discharges in LFP recordings were observed. Conclusion GIPC1 regulates epileptogenesis by interacting with mGluR7 and increasing its expression.
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Affiliation(s)
- Yong Liu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - You Wang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Juan Yang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China.,Department of Neurology, The Affiliated Hospital of Zunyi Medical University, Guizhou, China
| | - Tao Xu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Changhong Tan
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Peng Zhang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Qiankun Liu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Yangmei Chen
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
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Inhibition of AKT/GSK3β/CREB Pathway Improves the Responsiveness to AMPA Receptor Antagonists by Regulating GRIA1 Surface Expression in Chronic Epilepsy Rats. Biomedicines 2021; 9:biomedicines9040425. [PMID: 33919872 PMCID: PMC8103519 DOI: 10.3390/biomedicines9040425] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 12/15/2022] Open
Abstract
α-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) has been reported as one of the targets for treatment of epilepsy. Although maladaptive regulation of surface expression of glutamate ionotropic receptor AMPA type subunit 1 (GRIA1) subunit is relevant to the responsiveness to AMPAR antagonists (perampanel and GYKI 52466) in LiCl-pilocarpine-induced chronic epilepsy rats, the underlying mechanisms of refractory seizures to AMPAR antagonists have yet been unclear. In the present study, we found that both AMPAR antagonists restored the up-regulations of GRIA1 surface expression and Src family-mediated glycogen synthase kinase 3β (GSK3β)-Ca2+/cAMP response element-binding protein (CREB) phosphorylations to control levels in responders (whose seizure activities were responsive to AMPAR) but not non-responders (whose seizure activities were uncontrolled by AMPAR antagonists). In addition, 3-chloroacetyl indole (3CAI, an AKT inhibitor) co-treatment attenuated spontaneous seizure activities in non-responders, accompanied by reductions in AKT/GSK3β/CREB phosphorylations and GRIA1 surface expression. Although AMPAR antagonists reduced GRIA2 tyrosine (Y) phosphorylations in responders, they did not affect GRIA2 surface expression and protein interacting with C kinase 1 (PICK1) protein level in both responders and non-responders. Therefore, our findings suggest that dysregulation of AKT/GSK3β/CREB-mediated GRIA1 surface expression may be responsible for refractory seizures in non-responders, and that this pathway may be a potential target to improve the responsiveness to AMPAR antagonists.
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10
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Gregory KJ, Goudet C. International Union of Basic and Clinical Pharmacology. CXI. Pharmacology, Signaling, and Physiology of Metabotropic Glutamate Receptors. Pharmacol Rev 2020; 73:521-569. [PMID: 33361406 DOI: 10.1124/pr.119.019133] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors respond to glutamate, the major excitatory neurotransmitter in the mammalian brain, mediating a modulatory role that is critical for higher-order brain functions such as learning and memory. Since the first mGlu receptor was cloned in 1992, eight subtypes have been identified along with many isoforms and splice variants. The mGlu receptors are transmembrane-spanning proteins belonging to the class C G protein-coupled receptor family and represent attractive targets for a multitude of central nervous system disorders. Concerted drug discovery efforts over the past three decades have yielded a wealth of pharmacological tools including subtype-selective agents that competitively block or mimic the actions of glutamate or act allosterically via distinct sites to enhance or inhibit receptor activity. Herein, we review the physiologic and pathophysiological roles for individual mGlu receptor subtypes including the pleiotropic nature of intracellular signal transduction arising from each. We provide a comprehensive analysis of the in vitro and in vivo pharmacological properties of prototypical and commercially available orthosteric agonists and antagonists as well as allosteric modulators, including ligands that have entered clinical trials. Finally, we highlight emerging areas of research that hold promise to facilitate rational design of highly selective mGlu receptor-targeting therapeutics in the future. SIGNIFICANCE STATEMENT: The metabotropic glutamate receptors are attractive therapeutic targets for a range of psychiatric and neurological disorders. Over the past three decades, intense discovery efforts have yielded diverse pharmacological tools acting either competitively or allosterically, which have enabled dissection of fundamental biological process modulated by metabotropic glutamate receptors and established proof of concept for many therapeutic indications. We review metabotropic glutamate receptor molecular pharmacology and highlight emerging areas that are offering new avenues to selectively modulate neurotransmission.
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Affiliation(s)
- Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
| | - Cyril Goudet
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
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11
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Park D, Park S, Song J, Kang M, Lee S, Horak M, Suh YH. N‐linked glycosylation of the mGlu7 receptor regulates the forward trafficking and transsynaptic interaction with Elfn1. FASEB J 2020; 34:14977-14996. [DOI: 10.1096/fj.202001544r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/14/2020] [Accepted: 08/27/2020] [Indexed: 01/13/2023]
Affiliation(s)
- Da‐ha Park
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
| | - Sunha Park
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
| | - Jae‐man Song
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
| | - Minji Kang
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
| | - Sanghyeon Lee
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
| | - Martin Horak
- Institute of Physiology of the Czech Academy of Sciences Institute of Experimental Medicine of the Czech Academy of Sciences Prague 4 Czech Republic
| | - Young Ho Suh
- Department of Biomedical Sciences Neuroscience Research Institute Transplantation Research Institute Seoul National University College of Medicine Seoul South Korea
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12
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Neuroligin 2 regulates absence seizures and behavioral arrests through GABAergic transmission within the thalamocortical circuitry. Nat Commun 2020; 11:3744. [PMID: 32719346 PMCID: PMC7385104 DOI: 10.1038/s41467-020-17560-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 07/08/2020] [Indexed: 12/20/2022] Open
Abstract
Epilepsy and autism spectrum disorders (ASD) are two distinct brain disorders but have a high rate of co-occurrence, suggesting shared pathogenic mechanisms. Neuroligins are cell adhesion molecules important in synaptic function and ASD, but their role in epilepsy remains unknown. In this study, we show that Neuroligin 2 (NLG2) knockout mice exhibit abnormal spike and wave discharges (SWDs) and behavioral arrests characteristic of absence seizures. The anti-absence seizure drug ethosuximide blocks SWDs and rescues behavioral arrests and social memory impairment in the knockout mice. Restoring GABAergic transmission either by optogenetic activation of the thalamic reticular nucleus (nRT) presynaptic terminals or postsynaptic NLG2 expression in the thalamic neurons reduces the SWDs and behavioral arrests in the knockout mice. These results indicate that NLG2-mediated GABAergic transmission at the nRT-thalamic circuit represents a common mechanism underlying both epileptic seizures and ASD. Neuroligins are postsynaptic cell adhesion molecules that are involved in synapse function and autism spectrum disorder. The authors show that NLG2-mediated GABAergic transmission at the thalamic reticular nucleus-thalamic circuit is a common mechanism underlying epileptic seizures and ASD.
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13
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Fisher NM, Gould RW, Gogliotti RG, McDonald AJ, Badivuku H, Chennareddy S, Buch AB, Moore AM, Jenkins MT, Robb WH, Lindsley CW, Jones CK, Conn PJ, Niswender CM. Phenotypic profiling of mGlu 7 knockout mice reveals new implications for neurodevelopmental disorders. GENES BRAIN AND BEHAVIOR 2020; 19:e12654. [PMID: 32248644 DOI: 10.1111/gbb.12654] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/03/2020] [Accepted: 03/26/2020] [Indexed: 12/17/2022]
Abstract
Neurodevelopmental disorders are characterized by deficits in communication, cognition, attention, social behavior and/or motor control. Previous studies have pointed to the involvement of genes that regulate synaptic structure and function in the pathogenesis of these disorders. One such gene, GRM7, encodes the metabotropic glutamate receptor 7 (mGlu7 ), a G protein-coupled receptor that regulates presynaptic neurotransmitter release. Mutations and polymorphisms in GRM7 have been associated with neurodevelopmental disorders in clinical populations; however, limited preclinical studies have evaluated mGlu7 in the context of this specific disease class. Here, we show that the absence of mGlu7 in mice is sufficient to alter phenotypes within the domains of social behavior, associative learning, motor function, epilepsy and sleep. Moreover, Grm7 knockout mice exhibit an attenuated response to amphetamine. These findings provide rationale for further investigation of mGlu7 as a potential therapeutic target for neurodevelopmental disorders such as idiopathic autism, attention deficit hyperactivity disorder and Rett syndrome.
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Affiliation(s)
- Nicole M Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Robert W Gould
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Rocco G Gogliotti
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Annalise J McDonald
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Hana Badivuku
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Susmita Chennareddy
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Aditi B Buch
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Annah M Moore
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew T Jenkins
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - W Hudson Robb
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Carrie K Jones
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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14
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Marafi D, Mitani T, Isikay S, Hertecant J, Almannai M, Manickam K, Abou Jamra R, El-Hattab AW, Rajah J, Fatih JM, Du H, Karaca E, Bayram Y, Punetha J, Rosenfeld JA, Jhangiani SN, Boerwinkle E, Akdemir ZC, Erdin S, Hunter JV, Gibbs RA, Pehlivan D, Posey JE, Lupski JR. Biallelic GRM7 variants cause epilepsy, microcephaly, and cerebral atrophy. Ann Clin Transl Neurol 2020; 7:610-627. [PMID: 32286009 PMCID: PMC7261753 DOI: 10.1002/acn3.51003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 01/29/2023] Open
Abstract
Objective Defects in ion channels and neurotransmitter receptors are implicated in developmental and epileptic encephalopathy (DEE). Metabotropic glutamate receptor 7 (mGluR7), encoded by GRM7, is a presynaptic G‐protein‐coupled glutamate receptor critical for synaptic transmission. We previously proposed GRM7 as a candidate disease gene in two families with neurodevelopmental disorders (NDDs). One additional family has been published since. Here, we describe three additional families with GRM7 biallelic variants and deeply characterize the associated clinical neurological and electrophysiological phenotype and molecular data in 11 affected individuals from six unrelated families. Methods Exome sequencing and family‐based rare variant analyses on a cohort of 220 consanguineous families with NDDs revealed three families with GRM7 biallelic variants; three additional families were identified through literature search and collaboration with a clinical molecular laboratory. Results We compared the observed clinical features and variants of 11 affected individuals from the six unrelated families. Identified novel deleterious variants included two homozygous missense variants (c.2671G>A:p.Glu891Lys and c.1973G>A:p.Arg685Gln) and one homozygous stop‐gain variant (c.1975C>T:p.Arg659Ter). Developmental delay, neonatal‐ or infantile‐onset epilepsy, and microcephaly were universal. Three individuals had hypothalamic–pituitary–axis dysfunction without pituitary structural abnormality. Neuroimaging showed cerebral atrophy and hypomyelination in a majority of cases. Two siblings demonstrated progressive loss of myelination by 2 years in both and an acquired microcephaly pattern in one. Five individuals died in early or late childhood. Conclusion Detailed clinical characterization of 11 individuals from six unrelated families demonstrates that rare biallelic GRM7 pathogenic variants can cause DEEs, microcephaly, hypomyelination, and cerebral atrophy.
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Affiliation(s)
- Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Department of Pediatrics, Faculty of Medicine, Kuwait University, P.O. Box 24923, 13110, Safat, Kuwait
| | - Tadahiro Mitani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Sedat Isikay
- Department of Physiotherapy and Rehabilitation, School of Health Sciences, Hasan Kalyoncu University, Gaziantep, 27000, Turkey
| | - Jozef Hertecant
- Pediatric Metabolic and Genetics Division, Tawam Hospital, Al Ain, Abu Dhabi, United Arab Emirates
| | - Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, 11525, Saudi Arabia
| | - Kandamurugu Manickam
- Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, 04103, Leipzig, Germany
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Jaishen Rajah
- Sheikh Khalifa Medical City (SKMC), P.O. Box: 51900, Abu Dhabi, United Arab Emirates
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Ender Karaca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Yavuz Bayram
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jaya Punetha
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030
| | - Eric Boerwinkle
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030.,Human Genetics Center, University of Texas Health Science Center at Houston, Houston, Texas
| | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Serkan Erdin
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Jill V Hunter
- Texas Children's Hospital, Houston, Texas, 77030.,Department of Radiology, Baylor College of Medicine, Houston, Texas, 77030
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Texas Children's Hospital, Houston, Texas, 77030.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030.,Texas Children's Hospital, Houston, Texas, 77030.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, 77030
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15
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Turner C, De Luca M, Wolfheimer J, Hernandez N, Madsen KL, Schmidt HD. Administration of a novel high affinity PICK1 PDZ domain inhibitor attenuates cocaine seeking in rats. Neuropharmacology 2020; 164:107901. [PMID: 31805281 PMCID: PMC6954965 DOI: 10.1016/j.neuropharm.2019.107901] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/27/2019] [Accepted: 12/02/2019] [Indexed: 12/17/2022]
Abstract
Protein interacting with C kinase-1 (PICK1) regulates intra-cellular trafficking of GluA2-containing AMPA receptors, a process known to play a critical role in cocaine-seeking behavior. This suggests that PICK1 may represent a molecular target for developing novel pharmacotherapies to treat cocaine craving-induced relapse. Emerging evidence indicates that inhibition of PICK1 attenuates the reinstatement of cocaine-seeking behavior, an animal model of relapse. Here, we show that systemic administration of TAT-P4-(DATC5)2, a novel high-affinity peptide inhibitor of the PICK1 PDZ domain, dose-dependently attenuated the reinstatement of cocaine seeking in rats at doses that did not produce operant learning deficits or suppress locomotor activity. We also show that systemic TAT-P4-(DATC5)2 penetrated the brain where it was visualized in the nucleus accumbens shell. Consistent with these effects, infusions of TAT-P4-(DATC5)2 directly into the accumbens shell reduced cocaine, but not sucrose, seeking. The effects of TAT-P4-(DATC5)2 on cocaine seeking are likely due, in part, to inhibition of PICK1 in medium spiny neurons (MSNs) of the accumbens shell as TAT-P4-(DATC5)2 was shown to accumulate in striatal neurons and bind PICK1. Taken together, these findings highlight a novel role for PICK1 in the reinstatement of cocaine seeking and support future studies examining the efficacy of peptide inhibitors of PICK1 in animal and human models of cocaine relapse.
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Affiliation(s)
- Christopher Turner
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Marta De Luca
- Department of Neurosciences, Faculty of Health Sciences, University of Copenhagen Blegdamsvej 3, DK, 2200, Copenhagen, Denmark
| | - Jordan Wolfheimer
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nicole Hernandez
- Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kenneth Lindegaard Madsen
- Department of Neurosciences, Faculty of Health Sciences, University of Copenhagen Blegdamsvej 3, DK, 2200, Copenhagen, Denmark
| | - Heath D Schmidt
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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16
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Zhu L, Chen L, Xu P, Lu D, Dai S, Zhong L, Han Y, Zhang M, Xiao B, Chang L, Wu Q. Genetic and molecular basis of epilepsy-related cognitive dysfunction. Epilepsy Behav 2020; 104:106848. [PMID: 32028124 DOI: 10.1016/j.yebeh.2019.106848] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 02/02/2023]
Abstract
Epilepsy is a common neurological disease characterized by recurrent seizures. About 70 million people were affected by epilepsy or epileptic seizures. Epilepsy is a complicated complex or symptomatic syndromes induced by structural, functional, and genetic causes. Meanwhile, several comorbidities are accompanied by epileptic seizures. Cognitive dysfunction is a long-standing complication associated with epileptic seizures, which severely impairs quality of life. Although the definitive pathogenic mechanisms underlying epilepsy-related cognitive dysfunction remain unclear, accumulating evidence indicates that multiple risk factors are probably involved in the development and progression of cognitive dysfunction in patients with epilepsy. These factors include the underlying etiology, recurrent seizures or status epilepticus, structural damage that induced secondary epilepsy, genetic variants, and molecular alterations. In this review, we summarize several theories that may explain the genetic and molecular basis of epilepsy-related cognitive dysfunction.
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Affiliation(s)
- Lin Zhu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Lu Chen
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Puying Xu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Di Lu
- Biomedicine Engineering Research Center, Kunming Medical University, 1168 Chun Rong West Road, Kunming, Yunnan 650500, PR China
| | - Shujuan Dai
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Lianmei Zhong
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Yanbing Han
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, Hunan 410008, PR China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, Hunan 410008, PR China
| | - Lvhua Chang
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China.
| | - Qian Wu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China.
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17
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Chánez-Paredes S, Montoya-García A, Schnoor M. Cellular and pathophysiological consequences of Arp2/3 complex inhibition: role of inhibitory proteins and pharmacological compounds. Cell Mol Life Sci 2019; 76:3349-3361. [PMID: 31073744 PMCID: PMC11105272 DOI: 10.1007/s00018-019-03128-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 02/06/2023]
Abstract
The actin-related protein complex 2/3 (Arp2/3) generates branched actin networks important for many cellular processes such as motility, vesicular trafficking, cytokinesis, and intercellular junction formation and stabilization. Activation of Arp2/3 requires interaction with actin nucleation-promoting factors (NPFs). Regulation of Arp2/3 activity is achieved by endogenous inhibitory proteins through direct binding to Arp2/3 and competition with NPFs or by binding to Arp2/3-induced actin filaments and disassembly of branched actin networks. Arp2/3 inhibition has recently garnered more attention as it has been associated with attenuation of cancer progression, neurotoxic effects during drug abuse, and pathogen invasion of host cells. In this review, we summarize current knowledge on expression, inhibitory mechanisms and function of endogenous proteins able to inhibit Arp2/3 such as coronins, GMFs, PICK1, gadkin, and arpin. Moreover, we discuss cellular consequences of pharmacological Arp2/3 inhibition.
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Affiliation(s)
- Sandra Chánez-Paredes
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico
| | - Armando Montoya-García
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico
| | - Michael Schnoor
- Department for Molecular Biomedicine, CINVESTAV-IPN, Av. IPN 2508, San Pedro Zacatenco, GAM, 07360, Mexico City, Mexico.
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18
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Yu Y, Nguyen DT, Jiang J. G protein-coupled receptors in acquired epilepsy: Druggability and translatability. Prog Neurobiol 2019; 183:101682. [PMID: 31454545 DOI: 10.1016/j.pneurobio.2019.101682] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/09/2019] [Accepted: 08/15/2019] [Indexed: 02/06/2023]
Abstract
As the largest family of membrane proteins in the human genome, G protein-coupled receptors (GPCRs) constitute the targets of more than one-third of all modern medicinal drugs. In the central nervous system (CNS), widely distributed GPCRs in neuronal and nonneuronal cells mediate numerous essential physiological functions via regulating neurotransmission at the synapses. Whereas their abnormalities in expression and activity are involved in various neuropathological processes. CNS conditions thus remain highly represented among the indications of GPCR-targeted agents. Mounting evidence from a large number of animal studies suggests that GPCRs play important roles in the regulation of neuronal excitability associated with epilepsy, a common CNS disease afflicting approximately 1-2% of the population. Surprisingly, none of the US Food and Drug Administration (FDA)-approved (>30) antiepileptic drugs (AEDs) suppresses seizures through acting on GPCRs. This disparity raises concerns about the translatability of these preclinical findings and the druggability of GPCRs for seizure disorders. The currently available AEDs intervene seizures predominantly through targeting ion channels and have considerable limitations, as they often cause unbearable adverse effects, fail to control seizures in over 30% of patients, and merely provide symptomatic relief. Thus, identifying novel molecular targets for epilepsy is highly desired. Herein, we focus on recent progresses in understanding the comprehensive roles of several GPCR families in seizure generation and development of acquired epilepsy. We also dissect current hurdles hindering translational efforts in developing GPCRs as antiepileptic and/or antiepileptogenic targets and discuss the counteracting strategies that might lead to a potential cure for this debilitating CNS condition.
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Affiliation(s)
- Ying Yu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Drug Discovery Center, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Davis T Nguyen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Drug Discovery Center, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jianxiong Jiang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Drug Discovery Center, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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19
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Reiner A, Levitz J. Glutamatergic Signaling in the Central Nervous System: Ionotropic and Metabotropic Receptors in Concert. Neuron 2019; 98:1080-1098. [PMID: 29953871 DOI: 10.1016/j.neuron.2018.05.018] [Citation(s) in RCA: 348] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/19/2018] [Accepted: 05/10/2018] [Indexed: 12/28/2022]
Abstract
Glutamate serves as both the mammalian brain's primary excitatory neurotransmitter and as a key neuromodulator to control synapse and circuit function over a wide range of spatial and temporal scales. This functional diversity is decoded by two receptor families: ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). The challenges posed by the complexity and physiological importance of each of these subtypes has limited our appreciation and understanding of how these receptors work in concert. In this review, by comparing both receptor families with a focus on their crosstalk, we argue for a more holistic understanding of neural glutamate signaling.
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Affiliation(s)
- Andreas Reiner
- Department of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA.
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20
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Girard B, Tuduri P, Moreno MP, Sakkaki S, Barboux C, Bouschet T, Varrault A, Vitre J, McCort-Tranchepain I, Dairou J, Acher F, Fagni L, Marchi N, Perroy J, Bertaso F. The mGlu7 receptor provides protective effects against epileptogenesis and epileptic seizures. Neurobiol Dis 2019; 129:13-28. [PMID: 31051234 DOI: 10.1016/j.nbd.2019.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/28/2019] [Accepted: 04/29/2019] [Indexed: 01/26/2023] Open
Abstract
Finding new targets to control or reduce seizure activity is essential to improve the management of epileptic patients. We hypothesized that activation of the pre-synaptic and inhibitory metabotropic glutamate receptor type 7 (mGlu7) reduces spontaneous seizures. We tested LSP2-9166, a recently developed mGlu7/4 agonist with unprecedented potency on mGlu7 receptors, in two paradigms of epileptogenesis. In a model of chemically induced epileptogenesis (pentylenetetrazole systemic injection), LSP2-9166 induces an anti-epileptogenic effect rarely observed in preclinical studies. In particular, we found a bidirectional modulation of seizure progression by mGlu4 and mGlu7 receptors, the latter preventing kindling. In the intra-hippocampal injection of kainic acid mouse model that mimics the human mesial temporal lobe epilepsy, we found that LSP2-9166 reduces seizure frequency and hippocampal sclerosis. LSP2-9166 also acts as an anti-seizure drug on established seizures in both models tested. Specific modulation of the mGlu7 receptor could represent a novel approach to reduce pathological network remodeling.
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Affiliation(s)
- Benoit Girard
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | - Pola Tuduri
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | | | - Sophie Sakkaki
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | | | | | - Annie Varrault
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | - Jihane Vitre
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | | | | | | | - Laurent Fagni
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | - Nicola Marchi
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
| | - Julie Perroy
- IGF, CNRS, INSERM, Univ Montpellier, Montpellier, France
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21
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Celli R, Santolini I, Van Luijtelaar G, Ngomba RT, Bruno V, Nicoletti F. Targeting metabotropic glutamate receptors in the treatment of epilepsy: rationale and current status. Expert Opin Ther Targets 2019; 23:341-351. [PMID: 30801204 DOI: 10.1080/14728222.2019.1586885] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Several drugs targeting the GABAergic system are used in the treatment of epilepsy, but only one drug targeting glutamate receptors is on the market. This is surprising because an imbalance between excitatory and inhibitory neurotransmission lies at the core of the pathophysiology of epilepsy. One possible explanation is that drug development has been directed towards the synthesis of molecules that inhibit the activity of ionotropic glutamate receptors. These receptors mediate fast excitatory synaptic transmission in the central nervous system (CNS) and their blockade may cause severe adverse effects such as sedation, cognitive impairment, and psychotomimetic effects. Metabotropic glutamate (mGlu) receptors are more promising drug targets because these receptors modulate synaptic transmission rather than mediate it. Areas covered: We review the current evidence that links mGlu receptor subtypes to the pathophysiology and experimental treatment of convulsive and absence seizures. Expert opinion: While mGlu5 receptor negative allosteric modulators have the potential to be protective against convulsive seizures and hyperactivity-induced neurodegeneration, drugs that enhance mGlu5 and mGlu7 receptor function may have beneficial effects in the treatment of absence epilepsy. Evidence related to the other mGlu receptor subtypes is more fragmentary; further investigations are required for an improved understanding of their role in the generation and propagation of seizures.
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Affiliation(s)
| | | | | | | | - Valeria Bruno
- a IRCCS NEUROMED , Pozzilli , Italy.,d Departments of Physiology and Pharmacology , University Sapienza , Rome , Italy
| | - Ferdinando Nicoletti
- a IRCCS NEUROMED , Pozzilli , Italy.,d Departments of Physiology and Pharmacology , University Sapienza , Rome , Italy
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22
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Pereira V, Goudet C. Emerging Trends in Pain Modulation by Metabotropic Glutamate Receptors. Front Mol Neurosci 2019; 11:464. [PMID: 30662395 PMCID: PMC6328474 DOI: 10.3389/fnmol.2018.00464] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/30/2018] [Indexed: 12/20/2022] Open
Abstract
Pain is an essential protective mechanism meant to prevent tissue damages in organisms. On the other hand, chronic or persistent pain caused, for example, by inflammation or nerve injury is long lasting and responsible for long-term disability in patients. Therefore, chronic pain and its management represents a major public health problem. Hence, it is critical to better understand chronic pain molecular mechanisms to develop innovative and efficient drugs. Over the past decades, accumulating evidence has demonstrated a pivotal role of glutamate in pain sensation and transmission, supporting glutamate receptors as promising potential targets for pain relieving drug development. Glutamate is the most abundant excitatory neurotransmitter in the brain. Once released into the synapse, glutamate acts through ionotropic glutamate receptors (iGluRs), which are ligand-gated ion channels triggering fast excitatory neurotransmission, and metabotropic glutamate receptors (mGluRs), which are G protein-coupled receptors modulating synaptic transmission. Eight mGluRs subtypes have been identified and are divided into three classes based on their sequence similarities and their pharmacological and biochemical properties. Of note, all mGluR subtypes (except mGlu6 receptor) are expressed within the nociceptive pathways where they modulate pain transmission. This review will address the role of mGluRs in acute and persistent pain processing and emerging pharmacotherapies for pain management.
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Affiliation(s)
- Vanessa Pereira
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
| | - Cyril Goudet
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
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23
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Liu X, Fuentes EJ. Emerging Themes in PDZ Domain Signaling: Structure, Function, and Inhibition. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 343:129-218. [PMID: 30712672 PMCID: PMC7185565 DOI: 10.1016/bs.ircmb.2018.05.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Post-synaptic density-95, disks-large and zonula occludens-1 (PDZ) domains are small globular protein-protein interaction domains widely conserved from yeast to humans. They are composed of ∼90 amino acids and form a classical two α-helical/six β-strand structure. The prototypical ligand is the C-terminus of partner proteins; however, they also bind internal peptide sequences. Recent findings indicate that PDZ domains also bind phosphatidylinositides and cholesterol. Through their ligand interactions, PDZ domain proteins are critical for cellular trafficking and the surface retention of various ion channels. In addition, PDZ proteins are essential for neuronal signaling, memory, and learning. PDZ proteins also contribute to cytoskeletal dynamics by mediating interactions critical for maintaining cell-cell junctions, cell polarity, and cell migration. Given their important biological roles, it is not surprising that their dysfunction can lead to multiple disease states. As such, PDZ domain-containing proteins have emerged as potential targets for the development of small molecular inhibitors as therapeutic agents. Recent data suggest that the critical binding function of PDZ domains in cell signaling is more than just glue, and their binding function can be regulated by phosphorylation or allosterically by other binding partners. These studies also provide a wealth of structural and biophysical data that are beginning to reveal the physical features that endow this small modular domain with a central role in cell signaling.
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Affiliation(s)
- Xu Liu
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Ernesto J. Fuentes
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, United States
- Corresponding author: E-mail:
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24
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Fisher NM, Seto M, Lindsley CW, Niswender CM. Metabotropic Glutamate Receptor 7: A New Therapeutic Target in Neurodevelopmental Disorders. Front Mol Neurosci 2018; 11:387. [PMID: 30405350 PMCID: PMC6206046 DOI: 10.3389/fnmol.2018.00387] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/01/2018] [Indexed: 12/27/2022] Open
Abstract
Neurodevelopmental disorders (NDDs) are characterized by a wide range of symptoms including delayed speech, intellectual disability, motor dysfunction, social deficits, breathing problems, structural abnormalities, and epilepsy. Unfortunately, current treatment strategies are limited and innovative new approaches are sorely needed to address these complex diseases. The metabotropic glutamate receptors are a class of G protein-coupled receptors that act to modulate neurotransmission across many brain structures. They have shown great promise as drug targets for numerous neurological and psychiatric diseases. Moreover, the development of subtype-selective allosteric modulators has allowed detailed studies of each receptor subtype. Here, we focus on the metabotropic glutamate receptor 7 (mGlu7) as a potential therapeutic target for NDDs. mGlu7 is expressed widely throughout the brain in regions that correspond to the symptom domains listed above and has established roles in synaptic physiology and behavior. Single nucleotide polymorphisms and mutations in the GRM7 gene have been associated with idiopathic autism and other NDDs in patients. In rodent models, existing literature suggests that decreased mGlu7 expression and/or function may lead to symptoms that overlap with those of NDDs. Furthermore, potentiation of mGlu7 activity has shown efficacy in a mouse model of Rett syndrome. In this review, we summarize current findings that provide rationale for the continued development of mGlu7 modulators as potential therapeutics.
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Affiliation(s)
- Nicole M Fisher
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States
| | - Mabel Seto
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States
| | - Craig W Lindsley
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States.,Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Colleen M Niswender
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, United States
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25
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Ogiwara I, Miyamoto H, Tatsukawa T, Yamagata T, Nakayama T, Atapour N, Miura E, Mazaki E, Ernst SJ, Cao D, Ohtani H, Itohara S, Yanagawa Y, Montal M, Yuzaki M, Inoue Y, Hensch TK, Noebels JL, Yamakawa K. Nav1.2 haplodeficiency in excitatory neurons causes absence-like seizures in mice. Commun Biol 2018; 1:96. [PMID: 30175250 PMCID: PMC6115194 DOI: 10.1038/s42003-018-0099-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Mutations in the SCN2A gene encoding a voltage-gated sodium channel Nav1.2 are associated with epilepsies, intellectual disability, and autism. SCN2A gain-of-function mutations cause early-onset severe epilepsies, while loss-of-function mutations cause autism with milder and/or later-onset epilepsies. Here we show that both heterozygous Scn2a-knockout and knock-in mice harboring a patient-derived nonsense mutation exhibit ethosuximide-sensitive absence-like seizures associated with spike-and-wave discharges at adult stages. Unexpectedly, identical seizures are reproduced and even more prominent in mice with heterozygous Scn2a deletion specifically in dorsal-telencephalic (e.g., neocortical and hippocampal) excitatory neurons, but are undetected in mice with selective Scn2a deletion in inhibitory neurons. In adult cerebral cortex of wild-type mice, most Nav1.2 is expressed in excitatory neurons with a steady increase and redistribution from proximal (i.e., axon initial segments) to distal axons. These results indicate a pivotal role of Nav1.2 haplodeficiency in excitatory neurons in epilepsies of patients with SCN2A loss-of-function mutations.
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Affiliation(s)
- Ikuo Ogiwara
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Department of Physiology, Nippon Medical School, Tokyo, 113-8602, Japan
| | - Hiroyuki Miyamoto
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Laboratory for Neuronal Circuit Development, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,PRESTO, Japan Science and Technology Agency, Saitama, 332-0012, Japan
| | - Tetsuya Tatsukawa
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Tetsushi Yamagata
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Tojo Nakayama
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Department of Pediatrics, Tohoku University School of Medicine, Sendai, 980-8574, Japan.,Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Nafiseh Atapour
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Laboratory for Neuronal Circuit Development, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Department of Medicine (Royal Melbourne Hospital), Melbourne Brain Centre, University of Melbourne, Parkville, VIC, 3050, Australia
| | - Eriko Miura
- Department of Physiology, School of Medicine, Keio University, Tokyo, 160-8582, Japan
| | - Emi Mazaki
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Sara J Ernst
- Department of Neurology, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Dezhi Cao
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, 420-8688, Japan.,Neurology Department, Shenzhen Children's Hospital, 518026, Guangdong, China
| | - Hideyuki Ohtani
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, 420-8688, Japan
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,FIRST, Japan Science and Technology Agency, Saitama, 332-0012, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan.,CREST, Japan Science and Technology Agency, Saitama, 332-0012, Japan
| | - Mauricio Montal
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Michisuke Yuzaki
- Department of Physiology, School of Medicine, Keio University, Tokyo, 160-8582, Japan
| | - Yushi Inoue
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, 420-8688, Japan
| | - Takao K Hensch
- Laboratory for Neuronal Circuit Development, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA.,Department of Neurology, FM Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jeffrey L Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.
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26
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Suh YH, Chang K, Roche KW. Metabotropic glutamate receptor trafficking. Mol Cell Neurosci 2018; 91:10-24. [PMID: 29604330 DOI: 10.1016/j.mcn.2018.03.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/07/2018] [Accepted: 03/26/2018] [Indexed: 01/14/2023] Open
Abstract
The metabotropic glutamate receptors (mGlu receptors) are G protein-coupled receptors that bind to the excitatory neurotransmitter glutamate and are important in the modulation of neuronal excitability, synaptic transmission, and plasticity in the central nervous system. Trafficking of mGlu receptors in and out of the synaptic plasma membrane is a fundamental mechanism modulating excitatory synaptic function through regulation of receptor abundance, desensitization, and signaling profiles. In this review, we cover the regulatory mechanisms determining surface expression and endocytosis of mGlu receptors, with particular focus on post-translational modifications and receptor-protein interactions. The literature we review broadens our insight into the precise events defining the expression of functional mGlu receptors at synapses, and will likely contribute to the successful development of novel therapeutic targets for a variety of developmental, neurological, and psychiatric disorders.
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Affiliation(s)
- Young Ho Suh
- Department of Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, South Korea.
| | - Kai Chang
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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27
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Ngomba RT, van Luijtelaar G. Metabotropic glutamate receptors as drug targets for the treatment of absence epilepsy. Curr Opin Pharmacol 2018; 38:43-50. [PMID: 29547778 DOI: 10.1016/j.coph.2018.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/31/2018] [Indexed: 11/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are expressed in key regions of the cortex and the thalamus and are known to regulate spike and wave discharges (SWDs), the electroclinical hallmarks of absence seizures. Recent preclinical studies have highlighted the therapeutic potential of selective group I and III mGlu receptor subtype allosteric modulators, which can suppress pathological SWDs. Of particular interest are positive allosteric modulators (PAMs) for mGlu5 receptors, as they currently show the most promise as novel anti-absence epilepsy drugs. The rational design of novel selective positive and negative allosteric mGlu modulators, especially for the mGlu5 receptor, has been made possible following the recent crystallographic structure determination of group I mGlu receptors. Our current knowledge of the role of different mGlu receptor subtypes in absence epilepsy is outlined in this article.
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Affiliation(s)
- Richard Teke Ngomba
- School of Pharmacy in College of Science, University of Lincoln, Lincoln LN6 7TS, UK.
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28
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Manjunath GP, Ramanujam PL, Galande S. Structure function relations in PDZ-domain-containing proteins: Implications for protein networks in cellular signalling. J Biosci 2018; 43:155-171. [PMID: 29485124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Protein scaffolds as essential backbones for organization of supramolecular signalling complexes are a recurrent theme in several model systems. Scaffold proteins preferentially employ linear peptide binding motifs for recruiting their interaction partners. PDZ domains are one of the more commonly encountered peptide binding domains in several proteins including those involved in scaffolding functions. This domain is known for its promiscuity both in terms of ligand selection, mode of interaction with its ligands as well as its association with other protein interaction domains. PDZ domains are subject to several means of regulations by virtue of their functional diversity. Additionally, the PDZ domains are refractive to the effect of mutations and maintain their three-dimensional architecture under extreme mutational load. The biochemical and biophysical basis for this selectivity as well as promiscuity has been investigated and reviewed extensively. The present review focuses on the plasticity inherent in PDZ domains and its implications for modular organization as well as evolution of cellular signalling pathways in higher eukaryotes.
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Affiliation(s)
- G P Manjunath
- Indian Institute of Science Education and Research, Pune 411 008, India
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29
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Structure function relations in PDZ-domain-containing proteins: Implications for protein networks in cellular signalling. J Biosci 2017. [DOI: 10.1007/s12038-017-9727-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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30
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Palazzo E, Marabese I, de Novellis V, Rossi F, Maione S. Metabotropic Glutamate Receptor 7: From Synaptic Function to Therapeutic Implications. Curr Neuropharmacol 2017; 14:504-13. [PMID: 27306064 PMCID: PMC4983754 DOI: 10.2174/1570159x13666150716165323] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/20/2015] [Accepted: 07/14/2015] [Indexed: 11/22/2022] Open
Abstract
Metabotropic glutamate receptor 7 (mGluR7) is localized presynaptically at the active zone of neurotransmitter release. Unlike mGluR4 and mGluR8, which share mGluR7's presynaptic location, mGluR7 shows low affinity for glutamate and is activated only by high glutamate concentrations. Its wide distribution in the central nervous system (CNS) and evolutionary conservation across species suggest that mGluR7 plays a primary role in controlling excitatory synapse function. High mGluR7 expression has been observed in several brain regions that are critical for CNS functioning and are involved in neurological and psychiatric disorder development. Until the recent discovery of selective ligands for mGluR7, techniques to elucidate its role in neural function were limited to the use of knockout mice and gene silencing. Studies using these two techniques have revealed that mGluR7 modulates emotionality, stress and fear responses. N,N`-dibenzhydrylethane-1,2-diamine dihydrochloride (AMN082) was reported as the first selective mGluR7 allosteric agonist. Pharmacological effects of AMN082 have not completely confirmed the mGluR7-knockout mouse phenotype; this has been attributed to rapid receptor internalization after drug treatment and to the drug's apparent lack of in vivo selectivity. Therefore, the more recently developed mGluR7 negative allosteric modulators (NAMs) are crucial for understanding mGluR7 function and for exploiting its potential as a target for therapeutic interventions. This review presents the main findings regarding mGluR7's effect on modulation of synaptic function and its role in normal CNS function and in models of neurologic and psychiatric disorders.
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Affiliation(s)
- Enza Palazzo
- Department of Anesthesiology, Surgery and Emergency, The Second University of Naples, Piazza Luigi Miraglia 2, 80138 Naples, Italy.
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31
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32
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Multiple faces of protein interacting with C kinase 1 (PICK1): Structure, function, and diseases. Neurochem Int 2016; 98:115-21. [DOI: 10.1016/j.neuint.2016.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/02/2016] [Accepted: 03/02/2016] [Indexed: 11/19/2022]
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33
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Tassin V, Girard B, Chotte A, Fontanaud P, Rigault D, Kalinichev M, Perroy J, Acher F, Fagni L, Bertaso F. Phasic and Tonic mGlu7 Receptor Activity Modulates the Thalamocortical Network. Front Neural Circuits 2016; 10:31. [PMID: 27199672 PMCID: PMC4842779 DOI: 10.3389/fncir.2016.00031] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/05/2016] [Indexed: 11/13/2022] Open
Abstract
Mutation of the metabotropic glutamate receptor type 7 (mGlu7) induces absence-like epileptic seizures, but its precise role in the somatosensory thalamocortical network remains unknown. By combining electrophysiological recordings, optogenetics, and pharmacology, we dissected the contribution of the mGlu7 receptor at mouse thalamic synapses. We found that mGlu7 is functionally expressed at both glutamatergic and GABAergic synapses, where it can inhibit neurotransmission and regulate short-term plasticity. These effects depend on the PDZ-ligand of the receptor, as they are lost in mutant mice. Interestingly, the very low affinity of mGlu7 receptors for glutamate raises the question of how it can be activated, namely at GABAergic synapses and in basal conditions. Inactivation of the receptor activity with the mGlu7 negative allosteric modulator (NAM), ADX71743, enhances thalamic synaptic transmission. In vivo administration of the NAM induces a lethargic state with spindle and/or spike-and-wave discharges accompanied by a behavioral arrest typical of absence epileptic seizures. This provides evidence for mGlu7 receptor-mediated tonic modulation of a physiological function in vivo preventing synchronous and potentially pathological oscillations.
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Affiliation(s)
- Valériane Tassin
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | - Benoît Girard
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | - Apolline Chotte
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | - Pierre Fontanaud
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | | | | | - Julie Perroy
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | - Francine Acher
- CNRS, UMR-8601, Université Paris Descartes Paris, France
| | - Laurent Fagni
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
| | - Federica Bertaso
- CNRS, Institut de Génomique Fonctionnelle, UMR-5203Montpellier, France; INSERM, U1191Montpellier, France; UMR-5203, Université de MontpellierMontpellier, France
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34
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Li X, Markou A. Metabotropic Glutamate Receptor 7 (mGluR7) as a Target for the Treatment of Psychostimulant Dependence. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2016; 14:738-44. [PMID: 26022263 DOI: 10.2174/1871527314666150529145332] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 05/18/2015] [Indexed: 11/22/2022]
Abstract
Although few medications have been approved by the U.S. Food and Drug Administration (FDA) to assist people to quit tobacco smoking, there are no FDA-approved medications to treat dependence on other psychostimulant drugs, such as cocaine. The motivation to maintain psychostimulant drug seeking and self-administration involves alterations in glutamatergic neurotransmission. Thus, medications that modulate glutamate transmission may be effective treatments for psychostimulant dependence. One presynaptic inhibitory glutamate receptor that critically regulates glutamate transmission is the metabotropic glutamate 7 receptor (mGluR7). This review summarizes nonhuman experimental animal data that indicate a critical role for mGluR7 in drug-taking and drug-seeking behaviors for the psychostimulants cocaine and nicotine. AMN082, the only commercially available allosteric receptor agonist, has been used to investigate the role of mGluR7 in psychostimulant dependence. Systemic administration or microinjection of AMN082 into brain sites within the mesocorticolimbic system decreased self-administration and reinstatement of both cocaine and nicotine seeking. In vivo microdialysis results indicated that a nucleus accumbens-ventral pallidum γ-aminobutyric acid-ergic mechanism may underlie AMN082-induced antagonism of the reinforcing effects of cocaine, whereas a glutamate mGlu2/3 receptor mechanism underlies the AMN082-induced blockade of cocaine seeking. These findings indicate an important role for mGluR7 in mesolimbic areas in modulating the reinforcing effects of psychostimulant drugs, such as nicotine and cocaine, and the conditioned behaviors associated with drugs of abuse. Thus, selective mGluR7 agonists or positive allosteric modulators may have the potential to treat psychostimulant dependence.
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Affiliation(s)
| | - Athina Markou
- Department of Psychiatry, M/C 0603, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0603, USA.
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35
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Parihar R, Mishra R, Singh SK, Jayalakshmi S, Mehndiratta MM, Ganesh S. Association of the GRM4 gene variants with juvenile myoclonic epilepsy in an Indian population. J Genet 2015; 93:193-7. [PMID: 24840839 DOI: 10.1007/s12041-014-0334-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Rashmi Parihar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208 016, India.
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36
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Dunn HA, Ferguson SSG. PDZ Protein Regulation of G Protein–Coupled Receptor Trafficking and Signaling Pathways. Mol Pharmacol 2015; 88:624-39. [DOI: 10.1124/mol.115.098509] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
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37
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Cortical alterations in a model for absence epilepsy and febrile seizures: in vivo findings in mice carrying a human GABA(A)R gamma2 subunit mutation. Neurobiol Dis 2015; 77:62-70. [PMID: 25731747 DOI: 10.1016/j.nbd.2015.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/17/2015] [Accepted: 02/19/2015] [Indexed: 01/21/2023] Open
Abstract
Childhood absence epilepsy (CAE) is one of the most common forms of epilepsy among children. The study of a large Australian family demonstrated that a point mutation in the gene encoding the gamma2 subunit of the GABA(A) receptor (G2R43Q) leads to an autosomal dominantly inherited form of CAE and febrile seizures (FS). In a transgenic mouse model carrying the gamma2 (R43Q) mutation heterozygous animals recapitulate the human phenotype. In-vitro experiments indicated that this point mutation impairs cortical inhibition and thus increases the likelihood of seizures. Here, using whole-cell (WC) and extracellular (EC) recordings as well as voltage-sensitive dye imaging (VSDI), we systematically searched for an in vivo correlate of cortical alterations caused by the G2R43Q mutation, as suggested by the mentioned in vitro results. We measured spontaneous and whisker-evoked activity in the primary somatosensory cortex and ventral posteriomedial nucleus of the thalamus (VPM) before and after intraperitoneal injection of the ictogenic substance pentylenetetrazol (PTZ) in urethane-anesthetized G2R43Q mice and controls in a blinded setting. Compared to wildtype controls in G2R43Q mice after PTZ injection we found 1.) Increased cortical spontaneous activity in layer 2/3 and layer 5/6 pyramidal neurons (increased standard deviation of the mean membrane potential in WC recordings), 2.) Increased variance of stimulus evoked cortical responses in VSDI experiments. 3.) The cortical effects are not due to increased strength or precision of thalamic output. In summary our findings support the hypothesis of a cortical pathology in this mouse model of human genetic absence epilepsy. Further study is needed to characterize underlying molecular mechanisms.
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Metabotropic glutamate receptors as drug targets: what's new? Curr Opin Pharmacol 2014; 20:89-94. [PMID: 25506748 DOI: 10.1016/j.coph.2014.12.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 11/23/2022]
Abstract
The question in the title: 'what's new?' has two facets. First, are 'clinical' expectations met with success? Second, is the number of CNS disorders targeted by mGlu drugs still increasing? The answer to the first question is 'no', because development program with promising drugs in the treatment of schizophrenia, Parkinson's disease, and Fragile X syndrome have been discontinued. Nonetheless, we continue to be optimistic because there is still the concrete hope that some of these drugs are beneficial in targeted subpopulations of patients. The answer to the second question is 'yes', because mGlu ligands are promising targets for 'new' disorders such as type-1 spinocerebellar ataxia and absence epilepsy. In addition, the increasing availability of pharmacological tools may push mGlu7 and mGlu8 receptors into the clinical scenario. After almost 30 years from their discovery, mGlu receptors are still alive.
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Grillo-Bosch D, Choquet D, Sainlos M. Inhibition of PDZ domain-mediated interactions. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 10:e531-40. [PMID: 24451645 DOI: 10.1016/j.ddtec.2012.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Modulating protein-protein interactions constitutes a promising strategy both for the investigation of biological mechanisms and for developing new therapeutic approaches. Among the many types of inter-actions, PDZ domain-mediated interactions (PDMIs) have emerged over the last decade as attractive targets in the drug discovery field. Indeed, these small domains are involved in the regulation of many signaling pathways and possess structural properties which are favorable for the design of competing ligands. Herein, we describe the recent approaches developed to inhibit this class of protein-protein interactions.
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Hsu WCJ, Nilsson CL, Laezza F. Role of the axonal initial segment in psychiatric disorders: function, dysfunction, and intervention. Front Psychiatry 2014; 5:109. [PMID: 25191280 PMCID: PMC4139700 DOI: 10.3389/fpsyt.2014.00109] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 08/06/2014] [Indexed: 12/22/2022] Open
Abstract
The progress of developing effective interventions against psychiatric disorders has been limited due to a lack of understanding of the underlying cellular and functional mechanisms. Recent research findings focused on exploring novel causes of psychiatric disorders have highlighted the importance of the axonal initial segment (AIS), a highly specialized neuronal structure critical for spike initiation of the action potential. In particular, the role of voltage-gated sodium channels, and their interactions with other protein partners in a tightly regulated macromolecular complex has been emphasized as a key component in the regulation of neuronal excitability. Deficits and excesses of excitability have been linked to the pathogenesis of brain disorders. Identification of the factors and regulatory pathways involved in proper AIS function, or its disruption, can lead to the development of novel interventions that target these mechanistic interactions, increasing treatment efficacy while reducing deleterious off-target effects for psychiatric disorders.
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Affiliation(s)
- Wei-Chun Jim Hsu
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Graduate Program in Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- M.D.–Ph.D. Combined Degree Program, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Carol Lynn Nilsson
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Sealy Center for Molecular Medicine, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Center for Addiction Research, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Center for Biomedical Engineering, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
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Elfn1 recruits presynaptic mGluR7 in trans and its loss results in seizures. Nat Commun 2014; 5:4501. [PMID: 25047565 DOI: 10.1038/ncomms5501] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 06/23/2014] [Indexed: 01/08/2023] Open
Abstract
GABAergic interneurons are highly heterogeneous, and much is unknown about the specification and functional roles of their neural circuits. Here we show that a transinteraction of Elfn1 and mGluR7 controls targeted interneuron synapse development and that loss of Elfn1 results in hyperactivity and sensory-triggered epileptic seizures in mice. Elfn1 protein increases during postnatal development and localizes to postsynaptic sites of somatostatin-containing interneurons (SOM-INs) in the hippocampal CA1 stratum oriens and dentate gyrus (DG) hilus. Elfn1 knockout (KO) mice have deficits in mGluR7 recruitment to synaptic sites on SOM-INs, and presynaptic plasticity is impaired at these synapses. In patients with epilepsy and attention deficit hyperactivity disorder (ADHD), we find damaging missense mutations of ELFN1 that are clustered in the carboxy-terminal region required for mGluR7 recruitment. These results reveal a novel mechanism for interneuron subtype-specific neural circuit establishment and define a common basis bridging neurological disorders.
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42
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Yin S, Niswender CM. Progress toward advanced understanding of metabotropic glutamate receptors: structure, signaling and therapeutic indications. Cell Signal 2014; 26:2284-97. [PMID: 24793301 DOI: 10.1016/j.cellsig.2014.04.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/27/2014] [Indexed: 12/24/2022]
Abstract
The metabotropic glutamate (mGlu) receptors are a group of Class C seven-transmembrane spanning/G protein-coupled receptors (7TMRs/GPCRs). These receptors are activated by glutamate, one of the standard amino acids and the major excitatory neurotransmitter. By activating G protein-dependent and non-G protein-dependent signaling pathways, mGlus modulate glutamatergic transmission both in the periphery and throughout the central nervous system. Since the discovery of the first mGlu receptor, and especially during the last decade, a great deal of progress has been made in understanding the signaling, structure, pharmacological manipulation and therapeutic indications of the 8 mGlu members.
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Affiliation(s)
- Shen Yin
- Department of Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical School, Nashville, TN 37232, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical School, Nashville, TN 37232, USA.
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Baumgart S, Jansen F, Bintig W, Kalbe B, Herrmann C, Klumpers F, Köster SD, Scholz P, Rasche S, Dooley R, Metzler-Nolte N, Spehr M, Hatt H, Neuhaus EM. The scaffold protein MUPP1 regulates odorant-mediated signaling in olfactory sensory neurons. J Cell Sci 2014; 127:2518-27. [PMID: 24652834 DOI: 10.1242/jcs.144220] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The olfactory signal transduction cascade transforms odor information into electrical signals by a cAMP-based amplification mechanism. The mechanisms underlying the very precise temporal and spatial organization of the relevant signaling components remains poorly understood. Here, we identify, using co-immunoprecipitation experiments, a macromolecular assembly of signal transduction components in mouse olfactory neurons, organized through MUPP1. Disruption of the PDZ signaling complex, through use of an inhibitory peptide, strongly impaired odor responses and changed the activation kinetics of olfactory sensory neurons. In addition, our experiments demonstrate that termination of the response is dependent on PDZ-based scaffolding. These findings provide new insights into the functional organization, and regulation, of olfactory signal transduction.
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Affiliation(s)
- Sabrina Baumgart
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Fabian Jansen
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Willem Bintig
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Benjamin Kalbe
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Christian Herrmann
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Fabian Klumpers
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - S David Köster
- Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Paul Scholz
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Sebastian Rasche
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Ruth Dooley
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland
| | - Nils Metzler-Nolte
- Chair of Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH-Aachen University, Worringer Weg 1, 52074 Aachen, Germany
| | - Hanns Hatt
- Cell Physiology, Faculty for Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Eva M Neuhaus
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany Pharmacology and Toxicology, University Hospital Jena, Drakendorfer Weg 1, 07743 Jena, Germany
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Modulation of short-term plasticity in the corticothalamic circuit by group III metabotropic glutamate receptors. J Neurosci 2014; 34:675-87. [PMID: 24403165 DOI: 10.1523/jneurosci.1477-13.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recurrent connections in the corticothalamic circuit underlie oscillatory behavior in this network and range from normal sleep rhythms to the abnormal spike-wave discharges seen in absence epilepsy. The propensity of thalamic neurons to fire postinhibitory rebound bursts mediated by low-threshold calcium spikes renders the circuit vulnerable to both increased excitation and increased inhibition, such as excessive excitatory cortical drive to thalamic reticular (RT) neurons or heightened inhibition of thalamocortical relay (TC) neurons by RT. In this context, a protective role may be played by group III metabotropic receptors (mGluRs), which are uniquely located in the presynaptic active zone and typically act as autoreceptors or heteroceptors to depress synaptic release. Here, we report that these receptors regulate short-term plasticity at two loci in the corticothalamic circuit in rats: glutamatergic cortical synapses onto RT neurons and GABAergic synapses onto TC neurons in somatosensory ventrobasal thalamus. The net effect of group III mGluR activation at these synapses is to suppress thalamic oscillations as assayed in vitro. These findings suggest a functional role of these receptors to modulate corticothalamic transmission and protect against prolonged activity in the network.
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Fuxe K, Borroto-Escuela DO, Ciruela F, Guidolin D, Agnati LF. Receptor-receptor interactions in heteroreceptor complexes: a new principle in biology. Focus on their role in learning and memory. ACTA ACUST UNITED AC 2014. [DOI: 10.7243/2052-6946-2-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Iacovelli L, Felicioni M, Nisticò R, Nicoletti F, De Blasi A. Selective regulation of recombinantly expressed mGlu7 metabotropic glutamate receptors by G protein-coupled receptor kinases and arrestins. Neuropharmacology 2013; 77:303-12. [PMID: 24148810 DOI: 10.1016/j.neuropharm.2013.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/24/2013] [Accepted: 10/07/2013] [Indexed: 12/24/2022]
Abstract
mGlu7 receptors are coupled to Gi/Go-proteins and activate multiple transduction pathways, including inhibition of adenylyl cyclase activity and stimulation of ERK1/2 and JNK pathways. mGlu7 receptors play an important role in cognition and emotion and are involved in stress-related disorders such as anxiety and depression and in susceptibility to convulsive seizures. In spite of these potential clinical implications, little is known on the mechanisms that regulate mGlu7-receptor signaling. Here we show that mGlu7 receptor-dependent signaling pathways were regulated in a complementary manner by different GRK subtypes, with GRK4 affecting the adenylyl cyclase and the JNK pathways, and GRK2 selectively affecting the ERK1/2 pathway. Additionally we found that the two isoforms of non-visual arrestins, i.e. β-arrestin1 and β-arrestin2, exerted opposite effects on mGlu7-receptor signaling, with β-arrestin1 positively modulating ERK1/2 and inhibiting JNK, and β-arrestin2 doing the opposite. This represents a remarkable example of "reciprocal regulation" of receptor signaling by the two isoforms of β-arrestin. Finally we found that β-arrestin1 amplified mGlu7 receptor-dependent ERK1/2 activation in response to L-AP4 (an orthosteric agonist), but not in response to AMN082 (an atypical mGlu7-receptor allosteric agonist). The different effect of β-arrestin1 on L-AP4- and AMN082-stimulated ERK1/2 phosphorylation is in line with the emerging concept of β-arrestin-biased agonists. The present study may open new perspectives in elucidating the physio-pathological roles of the mGlu7 receptor and may provide new insights for the possibility to develop specific (biased) agonists that can selectively activate different signaling pathways.
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Affiliation(s)
- L Iacovelli
- Department of Physiology and Pharmacology "Vittorio Erspamer", University of Rome "Sapienza", P.le Aldo Moro, 5, 00185 Rome, Italy.
| | - M Felicioni
- IRCSS Fondazione Santa Lucia, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - R Nisticò
- Department of Physiology and Pharmacology "Vittorio Erspamer", University of Rome "Sapienza", P.le Aldo Moro, 5, 00185 Rome, Italy; IRCSS Fondazione Santa Lucia, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - F Nicoletti
- Department of Physiology and Pharmacology "Vittorio Erspamer", University of Rome "Sapienza", P.le Aldo Moro, 5, 00185 Rome, Italy; I.N.M. Neuromed, Località Camerelle, Pozzilli, Italy
| | - A De Blasi
- Dept. of Molecular Medicine, University of Rome "Sapienza", V.le Regina Elena 291, 00185 Rome, Italy
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Focant MC, Goursaud S, Boucherie C, Dumont AO, Hermans E. PICK1 expression in reactive astrocytes within the spinal cord of amyotrophic lateral sclerosis (ALS) rats. Neuropathol Appl Neurobiol 2013; 39:231-42. [PMID: 22624977 DOI: 10.1111/j.1365-2990.2012.01282.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AIMS The protein interacting with C kinase 1 (PICK1), a PDZ domain-containing protein mainly expressed in the central nervous system, interacts with the glutamate receptor subunit GluR2, with the glutamate transporter GLT-1b and with the enzyme serine racemase. These three proteins appear as key actors in the glutamate-mediated excitotoxicity associated with amyotrophic lateral sclerosis (ALS), in both patients and animal models of the disease. In this study, we examined the expression of PICK1 in the spinal cord of transgenic rats expressing a mutated form of the human superoxide dismutase 1 (hSOD1(G93A) ) during the progression of the disease. METHODS Expression of PICK1 was examined by real-time qPCR at presymptomatic and symptomatic stages as well as at end-stage. The expression of PICK1 in the different cell types of the spinal cord was examined by immunohistochemistry. RESULTS The overall expression of PICK1 is not modified in cervical and lumbar spinal cord of transgenic (hSOD1(G93A) ) rats during the progression of the disease. Nonetheless, immunohistochemical studies of lumbar ventral horns revealed a shift of PICK1 expression from motor neurones in healthy rats to activated astrocytes in end-stage hSOD1(G93A) animals. CONCLUSIONS Considering the documented influence of PICK1 expression on d-serine release and glutamate transport in astrocytes, these findings point to a potential implication of PICK1 in the progression of ALS.
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Affiliation(s)
- M C Focant
- Group of Neuropharmacology, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
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48
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Rickhag M, Owens WA, Winkler MT, Strandfelt KN, Rathje M, Sørensen G, Andresen B, Madsen KL, Jørgensen TN, Wörtwein G, Woldbye DPD, Sitte H, Daws LC, Gether U. Membrane-permeable C-terminal dopamine transporter peptides attenuate amphetamine-evoked dopamine release. J Biol Chem 2013; 288:27534-27544. [PMID: 23884410 DOI: 10.1074/jbc.m112.441295] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The dopamine transporter (DAT) is responsible for sequestration of extracellular dopamine (DA). The psychostimulant amphetamine (AMPH) is a DAT substrate, which is actively transported into the nerve terminal, eliciting vesicular depletion and reversal of DA transport via DAT. Here, we investigate the role of the DAT C terminus in AMPH-evoked DA efflux using cell-permeant dominant-negative peptides. A peptide, which corresponded to the last 24 C-terminal residues of DAT (TAT-C24 DAT) and thereby contained the Ca(2+)-calmodulin-dependent protein kinase IIα (CaMKIIα) binding domain and the PSD-95/Discs-large/ZO-1 (PDZ)-binding sequence of DAT, was made membrane-permeable by fusing it to the cell membrane transduction domain of the HIV-1 Tat protein (TAT-C24WT). The ability of TAT-C24WT but not a scrambled peptide (TAT-C24Scr) to block the CaMKIIα-DAT interaction was supported by co-immunoprecipitation experiments in heterologous cells. In heterologous cells, we also found that TAT-C24WT, but not TAT-C24Scr, decreased AMPH-evoked 1-methyl-4-phenylpyridinium efflux. Moreover, chronoamperometric recordings in striatum revealed diminished AMPH-evoked DA efflux in mice preinjected with TAT-C24WT. Both in heterologous cells and in striatum, the peptide did not further inhibit efflux upon KN-93-mediated inhibition of CaMKIIα activity, consistent with a dominant-negative action preventing binding of CaMKIIα to the DAT C terminus. This was further supported by the ability of a peptide with perturbed PDZ-binding sequence, but preserved CaMKIIα binding (TAT-C24AAA), to diminish AMPH-evoked DA efflux in vivo to the same extent as TAT-C24WT. Finally, AMPH-induced locomotor hyperactivity was attenuated following systemic administration of TAT-C24WT but not TAT-C24Scr. Summarized, our findings substantiate that DAT C-terminal protein-protein interactions are critical for AMPH-evoked DA efflux and suggest that it may be possible to target protein-protein interactions to modulate transporter function and interfere with psychostimulant effects.
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Affiliation(s)
- Mattias Rickhag
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - William A Owens
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Marie-Therese Winkler
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, A-1090 Vienna, Austria
| | - Kristine Nørgaard Strandfelt
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Mette Rathje
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Gunnar Sørensen
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark; Laboratory of Neuropsychiatry, Faculty of Health and Medical Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Bjørn Andresen
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Kenneth L Madsen
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Trine Nygaard Jørgensen
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Gitta Wörtwein
- Laboratory of Neuropsychiatry, Faculty of Health and Medical Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - David P D Woldbye
- Laboratory of Neuropsychiatry, Faculty of Health and Medical Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Harald Sitte
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University Vienna, A-1090 Vienna, Austria
| | - Lynette C Daws
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Ulrik Gether
- Molecular Neuropharmacology Laboratory, Lundbeck Foundation Center for Biomembranes in Nanomedicine, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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Bazyan AS, van Luijtelaar G. Neurochemical and behavioral features in genetic absence epilepsy and in acutely induced absence seizures. ISRN NEUROLOGY 2013; 2013:875834. [PMID: 23738145 PMCID: PMC3664506 DOI: 10.1155/2013/875834] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/06/2013] [Indexed: 02/08/2023]
Abstract
The absence epilepsy typical electroencephalographic pattern of sharp spikes and slow waves (SWDs) is considered to be due to an interaction of an initiation site in the cortex and a resonant circuit in the thalamus. The hyperpolarization-activated cyclic nucleotide-gated cationic I h pacemaker channels (HCN) play an important role in the enhanced cortical excitability. The role of thalamic HCN in SWD occurrence is less clear. Absence epilepsy in the WAG/Rij strain is accompanied by deficiency of the activity of dopaminergic system, which weakens the formation of an emotional positive state, causes depression-like symptoms, and counteracts learning and memory processes. It also enhances GABAA receptor activity in the striatum, globus pallidus, and reticular thalamic nucleus, causing a rise of SWD activity in the cortico-thalamo-cortical networks. One of the reasons for the occurrence of absences is that several genes coding of GABAA receptors are mutated. The question arises: what the role of DA receptors is. Two mechanisms that cause an infringement of the function of DA receptors in this genetic absence epilepsy model are proposed.
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Affiliation(s)
- A. S. Bazyan
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Russian Federation, 5A Butlerov Street, Moscow 117485, Russia
| | - G. van Luijtelaar
- Biological Psychology, Donders Centre for Cognition, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands
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50
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Focant MC, Hermans E. Protein interacting with C kinase and neurological disorders. Synapse 2013; 67:532-40. [DOI: 10.1002/syn.21657] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Accepted: 02/16/2013] [Indexed: 01/15/2023]
Affiliation(s)
- Marylène C. Focant
- Institute of Neuroscience, Université catholique de Louvain; Brussels; Belgium
| | - Emmanuel Hermans
- Institute of Neuroscience, Université catholique de Louvain; Brussels; Belgium
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