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Kandel MB, Zhuang GZ, Goins WF, Marzulli M, Zhang M, Glorioso JC, Kang Y, Levitt AE, Kwok WM, Levitt RC, Sarantopoulos KD. rdHSV-CA8 non-opioid analgesic gene therapy decreases somatosensory neuronal excitability by activating Kv7 voltage-gated potassium channels. Front Mol Neurosci 2024; 17:1398839. [PMID: 38783904 PMCID: PMC11112096 DOI: 10.3389/fnmol.2024.1398839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 04/18/2024] [Indexed: 05/25/2024] Open
Abstract
Chronic pain is common and inadequately treated, making the development of safe and effective analgesics a high priority. Our previous data indicate that carbonic anhydrase-8 (CA8) expression in dorsal root ganglia (DRG) mediates analgesia via inhibition of neuronal ER inositol trisphosphate receptor-1 (ITPR1) via subsequent decrease in ER calcium release and reduction of cytoplasmic free calcium, essential to the regulation of neuronal excitability. This study tested the hypothesis that novel JDNI8 replication-defective herpes simplex-1 viral vectors (rdHSV) carrying a CA8 transgene (vHCA8) reduce primary afferent neuronal excitability. Whole-cell current clamp recordings in small DRG neurons showed that vHCA8 transduction caused prolongation of their afterhyperpolarization (AHP), an essential regulator of neuronal excitability. This AHP prolongation was completely reversed by the specific Kv7 channel inhibitor XE-991. Voltage clamp recordings indicate an effect via Kv7 channels in vHCA8-infected small DRG neurons. These data demonstrate for the first time that vHCA8 produces Kv7 channel activation, which decreases neuronal excitability in nociceptors. This suppression of excitability may translate in vivo as non-opioid dependent behavioral- or clinical analgesia, if proven behaviorally and clinically.
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Affiliation(s)
- Munal B. Kandel
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Gerald Z. Zhuang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, United States
| | - William F. Goins
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Marco Marzulli
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Mingdi Zhang
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Joseph C. Glorioso
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Yuan Kang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Alexandra E. Levitt
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Wai-Meng Kwok
- Department of Anesthesiology and Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Roy C. Levitt
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- John T. MacDonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, United States
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Konstantinos D. Sarantopoulos
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
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2
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Rey Hipolito AG, van der Heijden ME, Sillitoe RV. Physiology of Dystonia: Animal Studies. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:163-215. [PMID: 37482392 DOI: 10.1016/bs.irn.2023.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Dystonia is currently ranked as the third most prevalent motor disorder. It is typically characterized by involuntary muscle over- or co-contractions that can cause painful abnormal postures and jerky movements. Dystonia is a heterogenous disorder-across patients, dystonic symptoms vary in their severity, body distribution, temporal pattern, onset, and progression. There are also a growing number of genes that are associated with hereditary dystonia. In addition, multiple brain regions are associated with dystonic symptoms in both genetic and sporadic forms of the disease. The heterogeneity of dystonia has made it difficult to fully understand its underlying pathophysiology. However, the use of animal models has been used to uncover the complex circuit mechanisms that lead to dystonic behaviors. Here, we summarize findings from animal models harboring mutations in dystonia-associated genes and phenotypic animal models with overt dystonic motor signs resulting from spontaneous mutations, neural circuit perturbations, or pharmacological manipulations. Taken together, an emerging picture depicts dystonia as a result of brain-wide network dysfunction driven by basal ganglia and cerebellar dysfunction. In the basal ganglia, changes in dopaminergic, serotonergic, noradrenergic, and cholinergic signaling are found across different animal models. In the cerebellum, abnormal burst firing activity is observed in multiple dystonia models. We are now beginning to unveil the extent to which these structures mechanistically interact with each other. Such mechanisms inspire the use of pre-clinical animal models that will be used to design new therapies including drug treatments and brain stimulation.
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Affiliation(s)
- Alejandro G Rey Hipolito
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Meike E van der Heijden
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Roy V Sillitoe
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States; Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States; Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States; Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States.
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3
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Bertling E, Blaesse P, Seja P, Kremneva E, Gateva G, Virtanen MA, Summanen M, Spoljaric I, Uvarov P, Blaesse M, Paavilainen VO, Vutskits L, Kaila K, Hotulainen P, Ruusuvuori E. Carbonic anhydrase seven bundles filamentous actin and regulates dendritic spine morphology and density. EMBO Rep 2021; 22:e50145. [PMID: 33719157 PMCID: PMC8025036 DOI: 10.15252/embr.202050145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 01/14/2021] [Accepted: 01/28/2021] [Indexed: 01/02/2023] Open
Abstract
Intracellular pH is a potent modulator of neuronal functions. By catalyzing (de)hydration of CO2 , intracellular carbonic anhydrase (CAi ) isoforms CA2 and CA7 contribute to neuronal pH buffering and dynamics. The presence of two highly active isoforms in neurons suggests that they may serve isozyme-specific functions unrelated to CO2 -(de)hydration. Here, we show that CA7, unlike CA2, binds to filamentous actin, and its overexpression induces formation of thick actin bundles and membrane protrusions in fibroblasts. In CA7-overexpressing neurons, CA7 is enriched in dendritic spines, which leads to aberrant spine morphology. We identified amino acids unique to CA7 that are required for direct actin interactions, promoting actin filament bundling and spine targeting. Disruption of CA7 expression in neocortical neurons leads to higher spine density due to increased proportion of small spines. Thus, our work demonstrates highly distinct subcellular expression patterns of CA7 and CA2, and a novel, structural role of CA7.
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Affiliation(s)
- Enni Bertling
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Peter Blaesse
- Institute of Physiology IWestfälische Wilhelms‐Universität MünsterMünsterGermany
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Patricia Seja
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Mari A Virtanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Milla Summanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Inkeri Spoljaric
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pavel Uvarov
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Laszlo Vutskits
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Kai Kaila
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pirta Hotulainen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Eva Ruusuvuori
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
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4
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Fujiwara Y, Yamane S, Harada N, Ikeguchi-Ogura E, Usui R, Nakamura T, Iwasaki K, Suzuki K, Yabe D, Hayashi Y, Inagaki N. Carbonic anhydrase 8 (CAR8) negatively regulates GLP-1 secretion from enteroendocrine cells in response to long-chain fatty acids. Am J Physiol Gastrointest Liver Physiol 2021; 320:G617-G626. [PMID: 33533304 DOI: 10.1152/ajpgi.00312.2020] [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: 08/27/2020] [Accepted: 01/30/2021] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin secreted from enteroendocrine preproglucagon (PPG)-expressing cells (traditionally known as L cells) in response to luminal nutrients that potentiates insulin secretion. Augmentation of endogenous GLP-1 secretion might well represent a novel therapeutic target for diabetes treatment in addition to the incretin-associated drugs currently in use. In this study, we found that PPG cells substantially express carbonic anhydrase 8 (CAR8), which has been reported to inhibit inositol 1,4,5-trisphosphate (IP3) binding to the IP3 receptor and subsequent Ca2+ efflux from the endoplasmic reticulum in neuronal cells. In vitro experiments using STC-1 cells demonstrated that Car8 knockdown increases long-chain fatty acid (LCFA)-stimulated GLP-1 secretion. This effect was reduced in the presence of phospholipase C (PLC) inhibitor; in addition, Car8 knockdown increased the intracellular Ca2+ elevation caused by α-linolenic acid, indicating that CAR8 exerts its effect on GLP-1 secretion via the PLC/IP3/Ca2+ pathway. Car8wdl null mutant mice showed significant increase in GLP-1 response to oral corn oil administration compared with that in wild-type littermates, with no significant change in intestinal GLP-1 content. These results demonstrate that CAR8 negatively regulates GLP-1 secretion from PPG cells in response to LCFAs, suggesting the possibility of augmentation of postprandial GLP-1 secretion by CAR8 inhibition.NEW & NOTEWORTHY This study focused on the physiological significance of carbonic anhydrase 8 (CAR8) in GLP-1 secretion from enteroendocrine preproglucagon (PPG)-expressing cells. We found an inhibitory role of CAR8 in LCFA-induced GLP-1 secretion in vitro and in vivo, suggesting a novel therapeutic approach to diabetes and obesity through augmentation of postprandial GLP-1 secretion by CAR8 inhibition.
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Affiliation(s)
- Yuta Fujiwara
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shunsuke Yamane
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Norio Harada
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Eri Ikeguchi-Ogura
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Ryota Usui
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Toshihiro Nakamura
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kanako Iwasaki
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kazuyo Suzuki
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Daisuke Yabe
- Department of Diabetes and Endocrinology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Yoshitaka Hayashi
- Department of Endocrinology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology, and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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5
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Upadhyay U, Zhuang GZ, Diatchenko L, Parisien M, Kang Y, Sarantopoulos KD, Martin ER, Smith SB, Maixner W, Levitt RC. Reversion mutation of cDNA CA8-204 minigene construct produces a truncated functional peptide that regulates calcium release in vitro and produces profound analgesia in vivo. Mamm Genome 2020; 31:287-294. [PMID: 33247772 DOI: 10.1007/s00335-020-09848-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/18/2020] [Indexed: 01/05/2023]
Abstract
Intracellular calcium is critical in orchestrating neuronal excitability and analgesia. Carbonic anhydrase-8 (CA8) regulates intracellular calcium signaling through allosteric inhibition of neuronal inositol trisphosphate receptor 1 (ITPR1) to produce profound analgesia. Recently, we reported the "G" allele at rs6471859 represents cis-eQTL regulating alternative splicing of a 1697 bp transcript (CA8-204G) with a retained intron, alternative polyadenylation site and a new stop codon producing a functional 26 kDa peptide with an extended exon 3. In this study we show the reversion mutation (G to C) at rs6471859 within the CA8-204G expression vector also produced a stable 1697 bp transcript (CA8-204C) coding for a smaller peptide (~ 22 kDa) containing only the first three CA8 exons. Surprisingly, this peptide inhibited ITPR1 (pITPR1) activation, ITPR1-mediated calcium release in vitro; and produced profound analgesia in vivo. This is the first report showing CA8-204C codes for a functional peptide sufficient to regulate calcium signaling and produce profound analgesia.
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Affiliation(s)
- Udita Upadhyay
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Gerald Z Zhuang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Luda Diatchenko
- Department of Anesthesiology, Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Marc Parisien
- Department of Anesthesiology, Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Yuan Kang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Konstantinos D Sarantopoulos
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Eden R Martin
- John T. MacDonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Shad B Smith
- Department of Anesthesiology, Center for Translational Pain Medicine, Duke University School of Medicine, Durham, NC, USA
| | - William Maixner
- Department of Anesthesiology, Center for Translational Pain Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Roy C Levitt
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA.
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
- John T. MacDonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA.
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA.
- University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8010A (R-371), Miami, FL, 33136, USA.
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6
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Rare CACNA1A mutations leading to congenital ataxia. Pflugers Arch 2020; 472:791-809. [DOI: 10.1007/s00424-020-02396-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 01/03/2023]
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7
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Sanyanga TA, Tastan Bishop Ö. Structural Characterization of Carbonic Anhydrase VIII and Effects of Missense Single Nucleotide Variations to Protein Structure and Function. Int J Mol Sci 2020; 21:E2764. [PMID: 32316137 PMCID: PMC7215520 DOI: 10.3390/ijms21082764] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 12/13/2022] Open
Abstract
Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues. The effects of four pathogenic nsSNVs, S100A, S100P, G162R and R237Q, and two benign S100L and E109D variants on CA-VIII structure and function was then investigated using molecular dynamics (MD) simulations, dynamic cross correlation (DCC) and dynamic residue network (DRN) analysis. SiteMap and CPORT analyses identified 38 unique CA-VIII residues that could potentially bind to ITPR1. MD analysis revealed less conformational sampling within the variant proteins and highlighted potential increases to variant protein rigidity. Dynamic cross correlation (DCC) showed that wild-type (WT) protein residue motion is predominately anti-correlated, with variant proteins showing no correlation to greater residue correlation. DRN revealed variant-associated increases to the accessibility of the N-terminal binding site residues, which could have implications for associations with ITPR1, and further highlighted differences to the mechanism of benign and pathogenic variants. SNV presence is associated with a reduction to the usage of Trp37 in all variants, which has implications for CA-VIII stability. The differences to variant mechanisms can be further investigated to understand pathogenesis of CAMRQ3, enhancing precision medicine-related studies into CA-VIII.
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MESH Headings
- Binding Sites
- Biomarkers, Tumor/chemistry
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Cerebellar Ataxia/genetics
- Cerebellar Ataxia/pathology
- Databases, Genetic
- Humans
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Intellectual Disability/genetics
- Intellectual Disability/pathology
- Molecular Dynamics Simulation
- Mutation, Missense
- Polymorphism, Single Nucleotide
- Protein Binding
- Protein Interaction Maps
- Protein Stability
- Protein Structure, Tertiary
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Affiliation(s)
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa;
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8
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Kuo SH, Louis ED, Faust PL, Handforth A, Chang SY, Avlar B, Lang EJ, Pan MK, Miterko LN, Brown AM, Sillitoe RV, Anderson CJ, Pulst SM, Gallagher MJ, Lyman KA, Chetkovich DM, Clark LN, Tio M, Tan EK, Elble RJ. Current Opinions and Consensus for Studying Tremor in Animal Models. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1036-1063. [PMID: 31124049 PMCID: PMC6872927 DOI: 10.1007/s12311-019-01037-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tremor is the most common movement disorder; however, we are just beginning to understand the brain circuitry that generates tremor. Various neuroimaging, neuropathological, and physiological studies in human tremor disorders have been performed to further our knowledge of tremor. But, the causal relationship between these observations and tremor is usually difficult to establish and detailed mechanisms are not sufficiently studied. To overcome these obstacles, animal models can provide an important means to look into human tremor disorders. In this manuscript, we will discuss the use of different species of animals (mice, rats, fruit flies, pigs, and monkeys) to model human tremor disorders. Several ways to manipulate the brain circuitry and physiology in these animal models (pharmacology, genetics, and lesioning) will also be discussed. Finally, we will discuss how these animal models can help us to gain knowledge of the pathophysiology of human tremor disorders, which could serve as a platform towards developing novel therapies for tremor.
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Affiliation(s)
- Sheng-Han Kuo
- Department of Neurology, Columbia University, 650 West 168th Street, Room 305, New York, NY, 10032, USA.
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 800 Howard Avenue, Ste Lower Level, New Haven, CT, 06519, USA.
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA.
- Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
| | - Adrian Handforth
- Neurology Service, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Su-Youne Chang
- Department of Neurologic Surgery and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Billur Avlar
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Eric J Lang
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Ming-Kai Pan
- Department of Medical Research and Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lauren N Miterko
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
| | - Amanda M Brown
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Collin J Anderson
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | | | - Kyle A Lyman
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Lorraine N Clark
- Department of Pathology and Cell Biology, Columbia University Medical Center and the New York Presbyterian Hospital, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Murni Tio
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Rodger J Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
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9
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Beaudin M, Matilla-Dueñas A, Soong BW, Pedroso JL, Barsottini OG, Mitoma H, Tsuji S, Schmahmann JD, Manto M, Rouleau GA, Klein C, Dupre N. The Classification of Autosomal Recessive Cerebellar Ataxias: a Consensus Statement from the Society for Research on the Cerebellum and Ataxias Task Force. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1098-1125. [PMID: 31267374 PMCID: PMC6867988 DOI: 10.1007/s12311-019-01052-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
There is currently no accepted classification of autosomal recessive cerebellar ataxias, a group of disorders characterized by important genetic heterogeneity and complex phenotypes. The objective of this task force was to build a consensus on the classification of autosomal recessive ataxias in order to develop a general approach to a patient presenting with ataxia, organize disorders according to clinical presentation, and define this field of research by identifying common pathogenic molecular mechanisms in these disorders. The work of this task force was based on a previously published systematic scoping review of the literature that identified autosomal recessive disorders characterized primarily by cerebellar motor dysfunction and cerebellar degeneration. The task force regrouped 12 international ataxia experts who decided on general orientation and specific issues. We identified 59 disorders that are classified as primary autosomal recessive cerebellar ataxias. For each of these disorders, we present geographical and ethnical specificities along with distinctive clinical and imagery features. These primary recessive ataxias were organized in a clinical and a pathophysiological classification, and we present a general clinical approach to the patient presenting with ataxia. We also identified a list of 48 complex multisystem disorders that are associated with ataxia and should be included in the differential diagnosis of autosomal recessive ataxias. This classification is the result of a consensus among a panel of international experts, and it promotes a unified understanding of autosomal recessive cerebellar disorders for clinicians and researchers.
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Affiliation(s)
- Marie Beaudin
- Axe Neurosciences, CHU de Québec-Université Laval, Québec, QC, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | - Antoni Matilla-Dueñas
- Department of Neuroscience, Health Sciences Research Institute Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
| | - Bing-Weng Soong
- Department of Neurology, Shuang Ho Hospital and Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan, Republic of China
- National Yang-Ming University School of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
| | - Jose Luiz Pedroso
- Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Orlando G Barsottini
- Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan
| | - Shoji Tsuji
- The University of Tokyo, Tokyo, Japan
- International University of Health and Welfare, Chiba, Japan
| | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000, Charleroi, Belgium
- Service des Neurosciences, UMons, Mons, Belgium
| | | | | | - Nicolas Dupre
- Axe Neurosciences, CHU de Québec-Université Laval, Québec, QC, Canada.
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada.
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10
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Finno CJ, Peterson J, Kang M, Park S, Bordbari MH, Durbin-Johnson B, Settles M, Perez-Flores MC, Lee JH, Yamoah EN. Single-Cell RNA-seq Reveals Profound Alterations in Mechanosensitive Dorsal Root Ganglion Neurons with Vitamin E Deficiency. iScience 2019; 21:720-735. [PMID: 31733517 PMCID: PMC6864320 DOI: 10.1016/j.isci.2019.10.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/16/2019] [Accepted: 10/28/2019] [Indexed: 12/26/2022] Open
Abstract
Ninety percent of Americans consume less than the estimated average requirements of dietary vitamin E (vitE). Severe vitE deficiency due to genetic mutations in the tocopherol transfer protein (TTPA) in humans results in ataxia with vitE deficiency (AVED), with proprioceptive deficits and somatosensory degeneration arising from dorsal root ganglia neurons (DRGNs). Single-cell RNA-sequencing of DRGNs was performed in Ttpa−/− mice, an established model of AVED. In stark contrast to expected changes in proprioceptive neurons, Ttpa−/− DRGNs showed marked upregulation of voltage-gated Ca2+ and K+ channels in mechanosensitive, tyrosine-hydroxylase positive (TH+) DRGNs. The ensuing significant conductance changes resulted in reduced excitability in mechanosensitive Ttpa−/− DRGNs. A highly supplemented vitE diet (600 mg dl-α-tocopheryl acetate/kg diet) prevented the cellular and molecular alterations and improved mechanosensation. VitE deficiency profoundly alters the molecular signature and functional properties of mechanosensitive TH+ DRGN, representing an intriguing shift of the prevailing paradigm from proprioception to mechanical sensation. vitE deficiency alters gene expression in DRGs Mechanosensitive TH+ DRG neurons are most affected K+ and Ca2+ current densities are increased in vitE-deficient TH+ DRG neurons High-dose vitE supplementation prevents the molecular phenotype
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Affiliation(s)
- Carrie J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | - Janel Peterson
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Mincheol Kang
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Seojin Park
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Matthew H Bordbari
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Blythe Durbin-Johnson
- Bioinformatics Core Facility, Genome Center, University of California, Davis, CA 95616, USA
| | - Matthew Settles
- Bioinformatics Core Facility, Genome Center, University of California, Davis, CA 95616, USA
| | - Maria C Perez-Flores
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Jeong H Lee
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Ebenezer N Yamoah
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
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11
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Upadhyay U, Zhuang GZ, Diatchenko L, Parisien M, Kang Y, Sarantopoulos KD, Martin ER, Smith SB, Maixner W, Levitt RC. Profound analgesia is associated with a truncated peptide resulting from tissue specific alternative splicing of DRG CA8-204 regulated by an exon-level cis-eQTL. PLoS Genet 2019; 15:e1008226. [PMID: 31199789 PMCID: PMC6615631 DOI: 10.1371/journal.pgen.1008226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 07/09/2019] [Accepted: 05/31/2019] [Indexed: 12/13/2022] Open
Abstract
Carbonic anhydrase-8 (CA8) is an intracellular protein that functions as an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1) critical to intracellular Ca++ release, synaptic functions and neuronal excitability. We showed previously that murine nociception and analgesic responses are regulated by the expression of this gene in dorsal root ganglion (DRG) associated with a cis-eQTL. In this report, we identify an exon-level cis-eQTL (rs6471859) that regulates human DRG CA8 alternative splicing, producing a truncated 1,697bp transcript (e.g., CA8-204). Our functional genomic studies show the “G” allele at rs6471859 produces a cryptic 3’UTR splice site regulating expression of CA8-204. We developed constructs to study the expression and function of the naturally occurring CA8-204G transcript (G allele at rs6471859), CA8-204C (C allele at rs6471859 reversion mutation) and CA8-201 (full length transcript). CA8-204G transcript expression occurred predominantly in non-neuronal cells (HEK293), while CA8-204C expression was restricted to neuronal derived cells (NBL) in vitro. CA8-204G produced a stable truncated transcript in HEK293 cells that was barely detectable in NBL cells. We also show CA8-204 produces a stable peptide that inhibits pITPR1 and Ca++ release in HEK293 cells. These results imply homozygous G/G individuals at rs6471859, which are common in the general population, produce exclusively CA8-204G that is barely detectable in neuronal cells. CA8 null mutations that greatly impact neuronal functions are associated with severe forms of spinal cerebellar ataxia, and our data suggest G/G homozygotes should display a similar phenotype. To address this question, we show in vivo using AAV8-FLAG-CA8-204G and AAV8-V5-CA8-201 gene transfer delivered via intra-neural sciatic nerve injection (SN), that these viral constructs are able to transduce DRG cells and produce similar analgesic and anti-hyperalgesic responses to inflammatory pain. Immunohistochemistry (IHC) examinations of DRG tissues further show CA8-204G peptide is expressed in advillin expressing neuronal cells, but to a lesser extent compared to glial cells. These findings explain why G/G homozygotes that exclusively produce this truncated functional peptide in DRG evade a severe phenotype. These genomic studies significantly advance the literature regarding structure-function studies on CA8-ITPR1 critical to calcium signaling pathways, synaptic functioning, neuronal excitability and analgesic responses. Carbonic anhydrase-8 (CA8) inhibits IP3 binding to the inositol trisphosphate receptor-1(ITPR1), which regulates intracellular calcium signaling critical to neuronal functions. Recessive CA8-null mutants are associated with spinocerebellar ataxia and neurodegenerative disorders. We have previously demonstrated that nociception and analgesic responses are associated with a DRG cis-eQTL that regulates murine expression of this gene. This study focuses on a human DRG exon-level cis-eQTL (rs6471859) that regulates CA8-204 alternative splicing producing a truncated 1,697bp transcript. Herein, we demonstrate the “G” allele at rs6471859 produces a cryptic 3’UTR splice site regulating tissue-specific CA8-204 expression. In vitro studies show the “G” allele (CA8-204G) produces a stable peptide that inhibits ITPR1 activation and Ca++ release in non-neuronal cells, but not in neuronal cells. However, using AAV8 gene transfer in vivo we show CA8-204G peptide is expressed in both glial and to a lesser extent in neuronal cells, producing profound analgesia and anti-hyperalgesia using inflammatory pain models, similar to the full length CA8-201 positive control. These data significantly extend our understanding of CA8 structure-function, demonstrating the truncated peptide may represent a novel therapeutic candidate.
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Affiliation(s)
- Udita Upadhyay
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Gerald Z. Zhuang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Luda Diatchenko
- Alan Edwards Centre for Research on Pain, McGill University Department of Anesthesiology, Montreal, Quebec, Canada
| | - Marc Parisien
- Alan Edwards Centre for Research on Pain, McGill University Department of Anesthesiology, Montreal, Quebec, Canada
| | - Yuan Kang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Konstantinos D. Sarantopoulos
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Eden R. Martin
- John T. MacDonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Shad B. Smith
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - William Maixner
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Roy C. Levitt
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- John T. MacDonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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12
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Miterko LN, Sillitoe RV. Climbing Fiber Development Is Impaired in Postnatal Car8 wdl Mice. THE CEREBELLUM 2019; 17:56-61. [PMID: 28940157 DOI: 10.1007/s12311-017-0886-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The cerebellum is critical for an array of motor functions. During postnatal development, the Purkinje cells (PCs) guide afferent topography to establish the final circuit. Perturbing PC morphogenesis or activity during development can result in climbing fiber (CF) multi-innervation or mis-patterning. Structural defects during circuit formation typically have long-term effects on behavior as they contribute to the phenotype of movement disorders such as cerebellar ataxia. The Car8 wdl mouse is one model in which early circuit destruction influences movement. However, although the loss of Car8 leads to the mis-wiring of afferent maps and abnormal PC firing, adult PC morphology is largely intact and there is no neurodegeneration. Here, we sought to uncover how defects in afferent connectivity arise in Car8 wdl mutants to resolve how functional deficits persist in motor diseases with subtle neuropathology. To address this problem, we analyzed CF development during the first 3 weeks of life. By immunolabeling CF terminals with VGLUT2, we found evidence of premature CF synapse elimination and delayed translocation from PC somata at postnatal day (P) 10 in Car8 wdl mice. Surprisingly, by P15, the wiring normalized, suggesting that CAR8 regulates the early but not the late stages of CF development. The data support the hypothesis of a defined sequence of events for cerebellar circuits to establish function.
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Affiliation(s)
- Lauren N Miterko
- Department of Pathology and Immunology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Program in Developmental Biology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA. .,Program in Developmental Biology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA. .,Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.
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13
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Miterko LN, White JJ, Lin T, Brown AM, O'Donovan KJ, Sillitoe RV. Persistent motor dysfunction despite homeostatic rescue of cerebellar morphogenesis in the Car8 waddles mutant mouse. Neural Dev 2019; 14:6. [PMID: 30867000 PMCID: PMC6417138 DOI: 10.1186/s13064-019-0130-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 02/20/2019] [Indexed: 12/19/2022] Open
Abstract
Background Purkinje cells play a central role in establishing the cerebellar circuit. Accordingly, disrupting Purkinje cell development impairs cerebellar morphogenesis and motor function. In the Car8wdl mouse model of hereditary ataxia, severe motor deficits arise despite the cerebellum overcoming initial defects in size and morphology. Methods To resolve how this compensation occurs, we asked how the loss of carbonic anhydrase 8 (CAR8), a regulator of IP3R1 Ca2+ signaling in Purkinje cells, alters cerebellar development in Car8wdl mice. Using a combination of histological, physiological, and behavioral analyses, we determined the extent to which the loss of CAR8 affects cerebellar anatomy, neuronal firing, and motor coordination during development. Results Our results reveal that granule cell proliferation is reduced in early postnatal mutants, although by the third postnatal week there is enhanced and prolonged proliferation, plus an upregulation of Sox2 expression in the inner EGL. Modified circuit patterning of Purkinje cells and Bergmann glia accompany these granule cell adjustments. We also find that although anatomy eventually normalizes, the abnormal activity of neurons and muscles persists. Conclusions Our data show that losing CAR8 only transiently restricts cerebellar growth, but permanently damages its function. These data support two current hypotheses about cerebellar development and disease: (1) Sox2 expression may be upregulated at sites of injury and contribute to the rescue of cerebellar structure and (2) transient delays to developmental processes may precede permanent motor dysfunction. Furthermore, we characterize waddles mutant mouse morphology and behavior during development and propose a Sox2-positive, cell-mediated role for rescue in a mouse model of human motor diseases. Electronic supplementary material The online version of this article (10.1186/s13064-019-0130-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lauren N Miterko
- Department of Pathology and Immunology, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Program in Developmental Biology, Baylor College of Medicine, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Joshua J White
- Department of Pathology and Immunology, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Department of Neuroscience, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Tao Lin
- Department of Pathology and Immunology, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Amanda M Brown
- Department of Pathology and Immunology, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Department of Neuroscience, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Kevin J O'Donovan
- Department of Chemistry and Life Science, United States Military Academy, West Point, New York, 10996, USA.,Burke Neurological Institute, Weill Cornell Medicine, White Plains, 10605, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA. .,Department of Neuroscience, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA. .,Program in Developmental Biology, Baylor College of Medicine, Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA. .,Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.
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14
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Aberrant IP 3 receptor activities revealed by comprehensive analysis of pathological mutations causing spinocerebellar ataxia 29. Proc Natl Acad Sci U S A 2018; 115:12259-12264. [PMID: 30429331 DOI: 10.1073/pnas.1811129115] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Spinocerebellar ataxia type 29 (SCA29) is autosomal dominant congenital ataxia characterized by early-onset motor delay, hypotonia, and gait ataxia. Recently, heterozygous missense mutations in an intracellular Ca2+ channel, inositol 1,4,5-trisphosphate (IP3) receptor type 1 (IP3R1), were identified as a cause of SCA29. However, the functional impacts of these mutations remain largely unknown. Here, we determined the molecular mechanisms by which pathological mutations affect IP3R1 activity and Ca2+ dynamics. Ca2+ imaging using IP3R-null HeLa cells generated by genome editing revealed that all SCA29 mutations identified within or near the IP3-binding domain of IP3R1 completely abolished channel activity. Among these mutations, R241K, T267M, T267R, R269G, R269W, S277I, K279E, A280D, and E497K impaired IP3 binding to IP3R1, whereas the T579I and N587D mutations disrupted channel activity without affecting IP3 binding, suggesting that T579I and N587D compromise channel gating mechanisms. Carbonic anhydrase-related protein VIII (CA8) is an IP3R1-regulating protein abundantly expressed in cerebellar Purkinje cells and is a causative gene of congenital ataxia. The SCA29 mutation V1538M within the CA8-binding site of IP3R1 completely eliminated its interaction with CA8 and CA8-mediated IP3R1 inhibition. Furthermore, pathological mutations in CA8 decreased CA8-mediated suppression of IP3R1 by reducing protein stability and the interaction with IP3R1. These results demonstrated the mechanisms by which pathological mutations cause IP3R1 dysfunction, i.e., the disruption of IP3 binding, IP3-mediated gating, and regulation via the IP3R-modulatory protein. The resulting aberrant Ca2+ homeostasis may contribute to the pathogenesis of cerebellar ataxia.
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15
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Shimobayashi E, Kapfhammer JP. Calcium Signaling, PKC Gamma, IP3R1 and CAR8 Link Spinocerebellar Ataxias and Purkinje Cell Dendritic Development. Curr Neuropharmacol 2018; 16:151-159. [PMID: 28554312 PMCID: PMC5883377 DOI: 10.2174/1570159x15666170529104000] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/16/2017] [Accepted: 05/25/2017] [Indexed: 01/05/2023] Open
Abstract
Background Spinocerebellar ataxias (SCAs) are a group of cerebellar diseases characterized by progressive ataxia and cerebellar atrophy. Several forms of SCAs are caused by missense mutations or deletions in genes related to calcium signaling in Purkinje cells. Among them, spinocerebellar ataxia type 14 (SCA14) is caused by missense mutations in PRKCG gene which encodes protein kinase C gamma (PKCγ). It is remarkable that in several cases in which SCA is caused by point mutations in an individual gene, the affected genes are involved in the PKCγ signaling pathway and calcium signaling which is not only crucial for proper Purkinje cell function but is also involved in the control of Purkinje cell dendritic development. In this review, we will focus on the PKCγ signaling related genes and calcium signaling related genes then discuss their role for both Purkinje cell dendritic development and cerebellar ataxia. Methods Research related to SCAs and Purkinje cell dendritic development is reviewed. Results PKCγ dysregulation causes abnormal Purkinje cell dendritic development and SCA14. Carbonic anhydrase related protein 8 (Car8) encoding CAR8 and Itpr1 encoding IP3R1were identified as upregulated genes in one of SCA14 mouse model. IP3R1, CAR8 and PKCγ proteins are strongly and specifically expressed in Purkinje cells. The common function among them is that they are involved in the regulation of calcium homeostasis in Purkinje cells and their dysfunction causes ataxia in mouse and human. Furthermore, disruption of intracellular calcium homeostasis caused by mutations in some calcium channels in Purkinje cells links to abnormal Purkinje cell dendritic development and the pathogenesis of several SCAs. Conclusion Once PKCγ signaling related genes and calcium signaling related genes are disturbed, the normal dendritic development of Purkinje cells is impaired as well as the integration of signals from other neurons, resulting in abnormal development, cerebellar dysfunction and eventually Purkinje cell loss.
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Affiliation(s)
- Etsuko Shimobayashi
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland
| | - Josef P Kapfhammer
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland
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16
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Human carbonic anhydrase-8 AAV8 gene therapy inhibits nerve growth factor signaling producing prolonged analgesia and anti-hyperalgesia in mice. Gene Ther 2018; 25:297-311. [PMID: 29789638 PMCID: PMC6063772 DOI: 10.1038/s41434-018-0018-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/16/2018] [Accepted: 02/15/2018] [Indexed: 01/02/2023]
Abstract
Carbonic anhydrase-8 (Car8; murine gene symbol) is an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1), which regulates neuronal intracellular calcium release. We previously reported that wildtype Car8 overexpression corrects the baseline allodynia and hyperalgesia associated with calcium dysregulation in the waddle (wdl) mouse due to a 19 bp deletion in exon 8 of the Car8 gene. In this report, we provide preliminary evidence that overexpression of the human wildtype ortholog of Car8 (CA8WT), but not the reported CA8 S100P loss-of-function mutation (CA8MT); inhibits nerve growth factor (NGF)-induced phosphorylation of ITPR1, TrkA (NGF high affinity receptor); and ITPR1-mediated cytoplasmic free calcium release in vitro. Additionally, we show that gene-transfer using AAV8-V5-CA8WT viral particles via sciatic nerve injection demonstrates retrograde transport to dorsal root ganglia (DRG) producing prolonged V5-CA8WT expression, pITPR1 and pTrkA inhibition, and profound analgesia and anti-hyperalgesia in male C57BL/6J mice. AAV8-V5-CA8WT mediated overexpression prevented and treated allodynia and hyperalgesia associated with chronic neuropathic pain produced by the spinal nerve ligation (SNL) model. These AAV8-V5-CA8 data provide a proof-of-concept for precision medicine through targeted gene therapy of NGF-responsive somatosensory neurons as a long-acting local analgesic able to prevent and treat chronic neuropathic pain through regulating TrkA signaling, ITPR1 activation, and intracellular free calcium release by ITPR1.
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17
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Shakkottai VG, Batla A, Bhatia K, Dauer WT, Dresel C, Niethammer M, Eidelberg D, Raike RS, Smith Y, Jinnah HA, Hess EJ, Meunier S, Hallett M, Fremont R, Khodakhah K, LeDoux MS, Popa T, Gallea C, Lehericy S, Bostan AC, Strick PL. Current Opinions and Areas of Consensus on the Role of the Cerebellum in Dystonia. THE CEREBELLUM 2017; 16:577-594. [PMID: 27734238 DOI: 10.1007/s12311-016-0825-6] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A role for the cerebellum in causing ataxia, a disorder characterized by uncoordinated movement, is widely accepted. Recent work has suggested that alterations in activity, connectivity, and structure of the cerebellum are also associated with dystonia, a neurological disorder characterized by abnormal and sustained muscle contractions often leading to abnormal maintained postures. In this manuscript, the authors discuss their views on how the cerebellum may play a role in dystonia. The following topics are discussed: The relationships between neuronal/network dysfunctions and motor abnormalities in rodent models of dystonia. Data about brain structure, cerebellar metabolism, cerebellar connections, and noninvasive cerebellar stimulation that support (or not) a role for the cerebellum in human dystonia. Connections between the cerebellum and motor cortical and sub-cortical structures that could support a role for the cerebellum in dystonia. Overall points of consensus include: Neuronal dysfunction originating in the cerebellum can drive dystonic movements in rodent model systems. Imaging and neurophysiological studies in humans suggest that the cerebellum plays a role in the pathophysiology of dystonia, but do not provide conclusive evidence that the cerebellum is the primary or sole neuroanatomical site of origin.
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Affiliation(s)
- Vikram G Shakkottai
- Department of Neurology, University of Michigan, Room 4009, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. .,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| | - Amit Batla
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, UK
| | - Kailash Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, UK
| | - William T Dauer
- Department of Neurology, University of Michigan, Room 4009, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Christian Dresel
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Martin Niethammer
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - David Eidelberg
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Robert S Raike
- Global Research Organization, Medtronic Inc. Neuromodulation, Minneapolis, MN, USA
| | - Yoland Smith
- Yerkes National Primate Center and Department of Neurology, Emory University, Atlanta, GA, USA
| | - H A Jinnah
- Department of Neurology, Human Genetics and Pediatrics, Emory University, Atlanta, GA, USA
| | - Ellen J Hess
- Departments of Pharmacology and Neurology, Emory University, Atlanta, GA, USA
| | - Sabine Meunier
- Institut du Cerveau et de la Moelle épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR, S 1127, Paris, France.,Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Rachel Fremont
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences, and The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, New York, NY, USA
| | - Mark S LeDoux
- Departments of Neurology, and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Traian Popa
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Cécile Gallea
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,Centre de NeuroImagerie de Recherche - CENIR, ICM, F-75013, Paris, France
| | - Stéphane Lehericy
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Andreea C Bostan
- Systems Neuroscience Institute and Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter L Strick
- Systems Neuroscience Institute and Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Neurobiology, University of Pittsburgh Brain Institute, University of Pittsburgh, Pittsburgh, PA, USA
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18
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Levitt RC, Zhuang GY, Kang Y, Erasso DM, Upadhyay U, Ozdemir M, Fu ES, Sarantopoulos KD, Smith SB, Maixner W, Diatchenko L, Martin ER, Wiltshire T. Car8 dorsal root ganglion expression and genetic regulation of analgesic responses are associated with a cis-eQTL in mice. Mamm Genome 2017; 28:407-415. [PMID: 28547032 DOI: 10.1007/s00335-017-9694-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 04/28/2017] [Indexed: 01/15/2023]
Abstract
Carbonic anhydrase-8 (Car8 mouse gene symbol) is devoid of enzymatic activity, but instead functions as an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1) to regulate this intracellular calcium release channel important in synaptic functions and neuronal excitability. Causative mutations in ITPR1 and carbonic anhydrase-8 in mice and humans are associated with certain subtypes of spinal cerebellar ataxia (SCA). SCA mice are genetically deficient in dorsal root ganglia (DRG) Car8 expression and display mechanical and thermal hypersensitivity and susceptibility to subacute and chronic inflammatory pain behaviors. In this report, we show that DRG Car8 expression is variable across 25 naïve-inbred strains of mice, and this cis-regulated eQTL (association between rs27660559, rs27706398, and rs27688767 and DRG Car8 expression; P < 1 × 10-11) is correlated with nociceptive responses in mice. Next, we hypothesized that increasing DRG Car8 gene expression would inhibit intracellular calcium release required for morphine antinociception and might correlate with antinociceptive sensitivity of morphine and perhaps other analgesic agents. We show that mean DRG Car8 gene expression is directly related to the dose of morphine or clonidine needed to provide a half-maximal analgesic response (r = 0.93, P < 0.00002; r = 0.83, P < 0.0008, respectively), suggesting that greater DRG Car8 expression increases analgesic requirements. Finally, we show that morphine induces intracellular free calcium release using Fura 2 calcium imaging in a dose-dependent manner; V5-Car8 WT overexpression in NBL cells inhibits morphine-induced calcium increase. These findings highlight the 'morphine paradox' whereby morphine provides antinociception by increasing intracellular free calcium, while Car8 and other antinociceptive agents work by decreasing intracellular free calcium. This is the first study demonstrating that biologic variability associated with this cis-eQTL may contribute to differing analgesic responses through altered regulation of ITPR1-dependent calcium release in mice.
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Affiliation(s)
- Roy C Levitt
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA.
- Bruce W. Carter Miami Veterans Healthcare System, Miami, FL, USA.
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA.
- John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Gerald Y Zhuang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Yuan Kang
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Diana M Erasso
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Udita Upadhyay
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Mehtap Ozdemir
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Eugene S Fu
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | - Konstantinos D Sarantopoulos
- Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Rosenstiel Medical Sciences Building - Room 8052A (R-371), Miami, FL, 33136, USA
| | | | | | | | - Eden R Martin
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
- John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Tim Wiltshire
- Department of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
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19
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Berridge MJ. The Inositol Trisphosphate/Calcium Signaling Pathway in Health and Disease. Physiol Rev 2016; 96:1261-96. [DOI: 10.1152/physrev.00006.2016] [Citation(s) in RCA: 377] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many cellular functions are regulated by calcium (Ca2+) signals that are generated by different signaling pathways. One of these is the inositol 1,4,5-trisphosphate/calcium (InsP3/Ca2+) signaling pathway that operates through either primary or modulatory mechanisms. In its primary role, it generates the Ca2+ that acts directly to control processes such as metabolism, secretion, fertilization, proliferation, and smooth muscle contraction. Its modulatory role occurs in excitable cells where it modulates the primary Ca2+ signal generated by the entry of Ca2+ through voltage-operated channels that releases Ca2+ from ryanodine receptors (RYRs) on the internal stores. In carrying out this modulatory role, the InsP3/Ca2+ signaling pathway induces subtle changes in the generation and function of the voltage-dependent primary Ca2+ signal. Changes in the nature of both the primary and modulatory roles of InsP3/Ca2+ signaling are a contributory factor responsible for the onset of a large number human diseases.
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Affiliation(s)
- Michael J. Berridge
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom
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20
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Zhao H, Carney KE, Falgoust L, Pan JW, Sun D, Zhang Z. Emerging roles of Na⁺/H⁺ exchangers in epilepsy and developmental brain disorders. Prog Neurobiol 2016; 138-140:19-35. [PMID: 26965387 DOI: 10.1016/j.pneurobio.2016.02.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/03/2016] [Accepted: 02/27/2016] [Indexed: 12/15/2022]
Abstract
Epilepsy is a common central nervous system (CNS) disease characterized by recurrent transient neurological events occurring due to abnormally excessive or synchronous neuronal activity in the brain. The CNS is affected by systemic acid-base disorders, and epileptic seizures are sensitive indicators of underlying imbalances in cellular pH regulation. Na(+)/H(+) exchangers (NHEs) are a family of membrane transporter proteins actively involved in regulating intracellular and organellar pH by extruding H(+) in exchange for Na(+) influx. Altering NHE function significantly influences neuronal excitability and plays a role in epilepsy. This review gives an overview of pH regulatory mechanisms in the brain with a special focus on the NHE family and the relationship between epilepsy and dysfunction of NHE isoforms. We first discuss how cells translocate acids and bases across the membrane and establish pH homeostasis as a result of the concerted effort of enzymes and ion transporters. We focus on the specific roles of the NHE family by detailing how the loss of NHE1 in two NHE mutant mice results in enhanced neuronal excitability in these animals. Furthermore, we highlight new findings on the link between mutations of NHE6 and NHE9 and developmental brain disorders including epilepsy, autism, and attention deficit hyperactivity disorder (ADHD). These studies demonstrate the importance of NHE proteins in maintaining H(+) homeostasis and their intricate roles in the regulation of neuronal function. A better understanding of the mechanisms underlying NHE1, 6, and 9 dysfunctions in epilepsy formation may advance the development of new epilepsy treatment strategies.
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Affiliation(s)
- Hanshu Zhao
- Department of Neurology, The First Affiliated Hospital of the Harbin Medical University, Harbin, China.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Karen E Carney
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lindsay Falgoust
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jullie W Pan
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA 15213, USA
| | - Zhongling Zhang
- Department of Neurology, The First Affiliated Hospital of the Harbin Medical University, Harbin, China
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21
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Bahamonde MI, Serra SA, Drechsel O, Rahman R, Marcé-Grau A, Prieto M, Ossowski S, Macaya A, Fernández-Fernández JM. A Single Amino Acid Deletion (ΔF1502) in the S6 Segment of CaV2.1 Domain III Associated with Congenital Ataxia Increases Channel Activity and Promotes Ca2+ Influx. PLoS One 2015; 10:e0146035. [PMID: 26716990 PMCID: PMC4696675 DOI: 10.1371/journal.pone.0146035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/11/2015] [Indexed: 02/07/2023] Open
Abstract
Mutations in the CACNA1A gene, encoding the pore-forming CaV2.1 (P/Q-type) channel α1A subunit, result in heterogeneous human neurological disorders, including familial and sporadic hemiplegic migraine along with episodic and progressive forms of ataxia. Hemiplegic Migraine (HM) mutations induce gain-of-channel function, mainly by shifting channel activation to lower voltages, whereas ataxia mutations mostly produce loss-of-channel function. However, some HM-linked gain-of-function mutations are also associated to congenital ataxia and/or cerebellar atrophy, including the deletion of a highly conserved phenylalanine located at the S6 pore region of α1A domain III (ΔF1502). Functional studies of ΔF1502 CaV2.1 channels, expressed in Xenopus oocytes, using the non-physiological Ba2+ as the charge carrier have only revealed discrete alterations in channel function of unclear pathophysiological relevance. Here, we report a second case of congenital ataxia linked to the ΔF1502 α1A mutation, detected by whole-exome sequencing, and analyze its functional consequences on CaV2.1 human channels heterologously expressed in mammalian tsA-201 HEK cells, using the physiological permeant ion Ca2+. ΔF1502 strongly decreases the voltage threshold for channel activation (by ~ 21 mV), allowing significantly higher Ca2+ current densities in a range of depolarized voltages with physiological relevance in neurons, even though maximal Ca2+ current density through ΔF1502 CaV2.1 channels is 60% lower than through wild-type channels. ΔF1502 accelerates activation kinetics and slows deactivation kinetics of CaV2.1 within a wide range of voltage depolarization. ΔF1502 also slowed CaV2.1 inactivation kinetic and shifted the inactivation curve to hyperpolarized potentials (by ~ 28 mV). ΔF1502 effects on CaV2.1 activation and deactivation properties seem to be of high physiological relevance. Thus, ΔF1502 strongly promotes Ca2+ influx in response to either single or trains of action potential-like waveforms of different durations. Our observations support a causative role of gain-of-function CaV2.1 mutations in congenital ataxia, a neurodevelopmental disorder at the severe-most end of CACNA1A-associated phenotypic spectrum.
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Affiliation(s)
- Maria Isabel Bahamonde
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Selma Angèlica Serra
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Oliver Drechsel
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Rubayte Rahman
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Anna Marcé-Grau
- Pediatric Neurology Research Group, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marta Prieto
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Stephan Ossowski
- Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Alfons Macaya
- Pediatric Neurology Research Group, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - José M. Fernández-Fernández
- Laboratori de Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail:
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22
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White JJ, Arancillo M, King A, Lin T, Miterko LN, Gebre SA, Sillitoe RV. Pathogenesis of severe ataxia and tremor without the typical signs of neurodegeneration. Neurobiol Dis 2015; 86:86-98. [PMID: 26586559 DOI: 10.1016/j.nbd.2015.11.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/30/2015] [Accepted: 11/11/2015] [Indexed: 11/27/2022] Open
Abstract
Neurological diseases are especially devastating when they involve neurodegeneration. Neuronal destruction is widespread in cognitive disorders such as Alzheimer's and regionally localized in motor disorders such as Parkinson's, Huntington's, and ataxia. But, surprisingly, the onset and progression of these diseases can occur without neurodegeneration. To understand the origins of diseases that do not have an obvious neuropathology, we tested how loss of CAR8, a regulator of IP3R1-mediated Ca(2+)-signaling, influences cerebellar circuit formation and neural function as movement deteriorates. We found that faulty molecular patterning, which shapes functional circuits called zones, leads to alterations in cerebellar wiring and Purkinje cell activity, but not to degeneration. Rescuing Purkinje cell function improved movement and reducing their Ca(2+) influx eliminated ectopic zones. Our findings in Car8(wdl) mutant mice unveil a pathophysiological mechanism that may operate broadly to impact motor and non-motor conditions that do not involve degeneration.
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Affiliation(s)
- Joshua J White
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Department of Neuroscience, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Marife Arancillo
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Annesha King
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Tao Lin
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Lauren N Miterko
- Program in Developmental Biology, Baylor College of Medicine, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Samrawit A Gebre
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Roy V Sillitoe
- Department of Pathology & Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Department of Neuroscience, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
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23
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Shimobayashi E, Wagner W, Kapfhammer JP. Carbonic Anhydrase 8 Expression in Purkinje Cells Is Controlled by PKCγ Activity and Regulates Purkinje Cell Dendritic Growth. Mol Neurobiol 2015; 53:5149-60. [PMID: 26399641 DOI: 10.1007/s12035-015-9444-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/14/2015] [Indexed: 10/23/2022]
Abstract
Purkinje cell dendritic development is severely compromised after chronic activation of protein kinase C (PKC). In a recent transgenic mouse model of spinocerebellar ataxia 14, the ser361-to-gly (S361G) mutation of the protein kinase C gamma (PKCγ) gene was expressed in Purkinje cells. Purkinje cells from these mutant mice in organotypic slice cultures have the same stunted dendritic tree as Purkinje cells after pharmacological activation of PKC. Because the transgene is exclusively present in Purkinje cells, cerebellar tissue from these mice is an attractive starting material for searching genes which might be interacting with PKCγ in Purkinje cells for inducing the stunted dendritic growth. We have performed a microarray analysis and identified several candidate genes with an increased messenger RNA (mRNA) expression in the PKCγ-S361G transgenic Purkinje cells. Out of these candidates, we have further studied carbonic anhydrase 8 (CA8). We show here that CA8 mRNA and protein expression is strongly induced in PKCγ-S361G transgenic Purkinje cells. Overexpression of CA8 in Purkinje cells in dissociated cultures strongly inhibited Purkinje cell dendritic development and produced a dendritic phenotype similar to PKCγ-S361G. There was no evidence for a direct binding of CA8 to either PKCγ or the type 1 IP3 receptor. Knockdown of CA8 with miRNA did not alter Purkinje cell dendritic development and did not protect Purkinje cells in dissociated cultures from the stunted dendritic growth induced by PKCγ-S361G or by PKC activation. Our results indicate that CA8 is a novel important regulator of Purkinje cell dendritic development and that its expression is controlled by PKCγ activity.
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Affiliation(s)
- Etsuko Shimobayashi
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, 4056, Basel, Switzerland
| | - Wolfgang Wagner
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Josef P Kapfhammer
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, 4056, Basel, Switzerland.
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24
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Jarius S, Wildemann B. 'Medusa-head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 1: Anti-mGluR1, anti-Homer-3, anti-Sj/ITPR1 and anti-CARP VIII. J Neuroinflammation 2015; 12:166. [PMID: 26377085 PMCID: PMC4574226 DOI: 10.1186/s12974-015-0356-y] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/02/2015] [Indexed: 01/09/2023] Open
Abstract
Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa-head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.
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Affiliation(s)
- S Jarius
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
| | - B Wildemann
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
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25
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Lamont MG, Weber JT. Mice deficient in carbonic anhydrase type 8 exhibit motor dysfunctions and abnormal calcium dynamics in the somatic region of cerebellar granule cells. Behav Brain Res 2015; 286:11-6. [DOI: 10.1016/j.bbr.2015.02.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 10/23/2022]
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26
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Carbonic anhydrase-8 regulates inflammatory pain by inhibiting the ITPR1-cytosolic free calcium pathway. PLoS One 2015; 10:e0118273. [PMID: 25734498 PMCID: PMC4347988 DOI: 10.1371/journal.pone.0118273] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/12/2015] [Indexed: 01/01/2023] Open
Abstract
Calcium dysregulation is causally linked with various forms of neuropathology including seizure disorders, multiple sclerosis, Huntington’s disease, Alzheimer’s, spinal cerebellar ataxia (SCA) and chronic pain. Carbonic anhydrase-8 (Car8) is an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1), which regulates intracellular calcium release fundamental to critical cellular functions including neuronal excitability, neurite outgrowth, neurotransmitter release, mitochondrial energy production and cell fate. In this report we test the hypothesis that Car8 regulation of ITPR1 and cytoplasmic free calcium release is critical to nociception and pain behaviors. We show Car8 null mutant mice (MT) exhibit mechanical allodynia and thermal hyperalgesia. Dorsal root ganglia (DRG) from MT also demonstrate increased steady-state ITPR1 phosphorylation (pITPR1) and cytoplasmic free calcium release. Overexpression of Car8 wildtype protein in MT nociceptors complements Car8 deficiency, down regulates pITPR1 and abolishes thermal and mechanical hypersensitivity. We also show that Car8 nociceptor overexpression alleviates chronic inflammatory pain. Finally, inflammation results in downregulation of DRG Car8 that is associated with increased pITPR1 expression relative to ITPR1, suggesting a possible mechanism of acute hypersensitivity. Our findings indicate Car8 regulates the ITPR1-cytosolic free calcium pathway that is critical to nociception, inflammatory pain and possibly other neuropathological states. Car8 and ITPR1 represent new therapeutic targets for chronic pain.
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27
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A new mouse allele of glutamate receptor delta 2 with cerebellar atrophy and progressive ataxia. PLoS One 2014; 9:e107867. [PMID: 25250835 PMCID: PMC4176021 DOI: 10.1371/journal.pone.0107867] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 08/21/2014] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar degenerations (SCDs) are a large class of sporadic or hereditary neurodegenerative disorders characterized by progressive motion defects and degenerative changes in the cerebellum and other parts of the CNS. Here we report the identification and establishment from a C57BL/6J mouse colony of a novel mouse line developing spontaneous progressive ataxia, which we refer to as ts3. Frequency of the phenotypic expression was consistent with an autosomal recessive Mendelian trait of inheritance, suggesting that a single gene mutation is responsible for the ataxic phenotype of this line. The onset of ataxia was observed at about three weeks of age, which slowly progressed until the hind limbs became entirely paralyzed in many cases. Micro-MRI study revealed significant cerebellar atrophy in all the ataxic mice, although individual variations were observed. Detailed histological analyses demonstrated significant atrophy of the anterior folia with reduced granule cells (GC) and abnormal morphology of cerebellar Purkinje cells (PC). Study by ultra-high voltage electron microscopy (UHVEM) further indicated aberrant morphology of PC dendrites and their spines, suggesting both morphological and functional abnormalities of the PC in the mutants. Immunohistochemical studies also revealed defects in parallel fiber (PF)-PC synapse formation and abnormal distal extension of climbing fibers (CF). Based on the phenotypic similarities of the ts3 mutant with other known ataxic mutants, we performed immunohistological analyses and found that expression levels of two genes and their products, glutamate receptor delta2 (grid2) and its ligand, cerebellin1 (Cbln1), are significantly reduced or undetectable. Finally, we sequenced the candidate genes and detected a large deletion in the coding region of the grid2 gene. Our present study suggests that ts3 is a new allele of the grid2 gene, which causes similar but different phenotypes as compared to other grid2 mutants.
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28
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Effects of carbonic anhydrase-related protein VIII on human cells harbouring an A8344G mitochondrial DNA mutation. Biochem J 2014; 459:149-60. [PMID: 24476000 DOI: 10.1042/bj20131235] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MERRF (myoclonus epilepsy associated with ragged-red fibres) is a maternally inherited mitochondrial encephalomyopathy with various syndromes involving both muscular and nervous systems. The most common mutation in MERRF syndrome, the A8344G mutation in mtDNA, has been associated with severe defects in the respiratory function of mitochondria. In the present study, we show that there is a significant decrease in CA8 (carbonic anhydrase-related protein VIII) in cybrids harbouring the MERRF A8344G mutation. CA8 deficiency and mutations were found to be associated with a distinctive lifelong gait disorder in wdl (Waddles) mice and novel syndromes characterized by cerebellar ataxia and mental retardation in humans. The results of the present study showed that overexpression of CA8 in MERRF cybrids significantly decreased cell death induced by STS (staurosporine) treatment, suggesting a protective function of CA8 in cells harbouring the A8344G mutation of mtDNA. Interestingly, an increase in the formation of LC3-II (microtubule-associated protein 1 light chain 3-II) was found in the cybrids with down-regulated CA8 expression, suggesting that reduced expression of CA8 leads to autophagy activation. Furthermore, cybrids exhibiting down-regulated CA8 showed increased cytosolic Ca2+ signals and reduced levels of phospho-Akt compared with those in the cybrids with overexpressed CA8, indicating that phospho-Akt is involved in the protection of cells by CA8. Our findings suggest that CA8 is involved in the autophagic pathway and may have a protective role in cultured cells from patients with MERRF. Targeting CA8 and the downstream autophagic pathway might help develop therapeutic agents for treatment of MERRF syndrome in the future.
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29
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Abstract
H(+) ions are remarkably efficient modulators of neuronal excitability. This renders brain functions highly sensitive to small changes in pH which are generated "extrinsically" via mechanisms that regulate the acid-base status of the whole organism; and "intrinsically", by activity-induced transmembrane fluxes and de novo generation of acid-base equivalents. The effects of pH changes on neuronal excitability are mediated by diverse, largely synergistically-acting mechanisms operating at the level of voltage- and ligand-gated ion channels and gap junctions. In general, alkaline shifts induce an increase in excitability which is often intense enough to trigger epileptiform activity, while acidosis has the opposite effect. Brain pH changes show a wide variability in their spatiotemporal properties, ranging from long-lasting global shifts to fast and highly localized transients that take place in subcellular microdomains. Thirteen catalytically-active mammalian carbonic anhydrase isoforms have been identified, whereof 11 are expressed in the brain. Distinct CA isoforms which have their catalytic sites within brain cells and the interstitial fluid exert a remarkably strong influence on the dynamics of pH shifts and, consequently, on neuronal functions. In this review, we will discuss the various roles of H(+) as an intra- and extracellular signaling factor in the brain, focusing on the effects mediated by CAs. Special attention is paid on the developmental expression patterns and actions of the neuronal isoform, CA VII. Studies on the various functions of CAs will shed light on fundamental mechanisms underlying neuronal development, signaling and plasticity; on pathophysiological mechanisms associated with epilepsy and related diseases; and on the modes of action of CA inhibitors used as CNS-targeting drugs.
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Affiliation(s)
- Eva Ruusuvuori
- Department of Biosciences, University of Helsinki, Helsinki, Finland,
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Aspatwar A, Tolvanen MEE, Jokitalo E, Parikka M, Ortutay C, Harjula SKE, Rämet M, Vihinen M, Parkkila S. Abnormal cerebellar development and ataxia in CARP VIII morphant zebrafish. Hum Mol Genet 2012; 22:417-32. [PMID: 23087022 DOI: 10.1093/hmg/dds438] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Congenital ataxia and mental retardation are mainly caused by variations in the genes that affect brain development. Recent reports have shown that mutations in the CA8 gene are associated with mental retardation and ataxia in humans and ataxia in mice. The gene product, carbonic anhydrase-related protein VIII (CARP VIII), is predominantly present in cerebellar Purkinje cells, where it interacts with the inositol 1,4,5-trisphosphate receptor type 1, a calcium channel. In this study, we investigated the effects of the loss of function of CARP VIII during embryonic development in zebrafish using antisense morpholino oligonucleotides against the CA8 gene. Knockdown of CA8 in zebrafish larvae resulted in a curved body axis, pericardial edema and abnormal movement patterns. Histologic examination revealed gross morphologic defects in the cerebellar region and in the muscle. Electron microscopy studies showed increased neuronal cell death in developing larvae injected with CA8 antisense morpholinos. These data suggest a pivotal role for CARP VIII during embryonic development. Furthermore, suppression of CA8 expression leads to defects in motor and coordination functions, mimicking the ataxic human phenotype. This work reveals an evolutionarily conserved function of CARP VIII in brain development and introduces a novel zebrafish model in which to investigate the mechanisms of CARP VIII-related ataxia and mental retardation in humans.
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Affiliation(s)
- Ashok Aspatwar
- Institute of Biomedical Technology and School of Medicine, University of Tampere and BioMediTech, Tampere 33014, Finland.
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31
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Abstract
Innervation of Purkinje cells (PCs) by multiple climbing fibers (CFs) is refined into mono-innervation during the first three postnatal weeks of rodents' lives. In this review article, we will integrate the current knowledge on developmental process and mechanisms of CF synapse elimination. In the 'creeper' stage of CF innervation (postnatal day 0 (P0)∼), CFs creep among PC somata to form transient synapses on immature dendrites. In the 'pericellular nest' stage (P5∼), CFs densely surround and innervate PC somata. CF innervation is then displaced to the apical portion of PC somata in the 'capuchon' stage (P9∼), and translocate to dendrites in the 'dendritic' (P12∼) stage. Along with the developmental changes in CF wiring, functional and morphological distinctions become larger among CF inputs. PCs are initially innervated by more than five CFs with similar strengths (∼P3). During P3-7 only a single CF is selectively strengthened (functional differentiation), and it undergoes dendritic translocation from P9 on (dendritic translocation). Following the functional differentiation, perisomatic CF synapses are eliminated nonselectively; this proceeds in two distinct phases. The early phase (P7-11) is conducted independently of parallel fiber (PF)-PC synapse formation, while the late phase (P12-17) critically depends on it. The P/Q-type voltage-dependent Ca(2+) channel in PCs triggers selective strengthening of single CF inputs, promotes dendritic translocation of the strengthened CFs, and drives the early phase of CF synapse elimination. In contrast, the late phase is mediated by the mGluR1-Gαq-PLCβ4-PKCγ signaling cascade in PCs driven at PF-PC synapses, whose structural connectivity is stabilized and maintained by the GluRδ2-Cbln1-neurexin system.
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Affiliation(s)
- Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
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32
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Sherman TA, Rongali SC, Matthews TA, Pfeiffer J, Nehrke K. Identification of a nuclear carbonic anhydrase in Caenorhabditis elegans. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:808-17. [PMID: 22245567 DOI: 10.1016/j.bbamcr.2011.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 12/01/2011] [Accepted: 12/13/2011] [Indexed: 12/27/2022]
Abstract
BACKGROUND Carbonic anhydrases (CA) catalyze the inter-conversion of CO(2) with HCO(3) and H(+), and are involved in a wide variety of physiologic processes such as anion transport, pH regulation, and water balance. In mammals there are sixteen members of the classical α-type CA family, while the simple genetic model organism Caenorhabditis elegans codes for six αCA isoforms (cah-1 through cah-6). METHODS Fluorescent reporter constructs were used to analyze gene promoter usage, splice variation, and protein localization in transgenic worms. Catalytic activity of recombinant CA proteins was assessed using Hansson's histochemistry. CA's ability to regulate pH as a function of CO(2) and HCO(3) was measured using dynamic fluorescent imaging of genetically-targeted biosensors. RESULTS Each of the six CA genes was found to be expressed in a distinct repertoire of cell types. Surprisingly, worms also expressed a catalytically-active CA splice variant, cah-4a, in which an alternative first exon targeted the protein to the nucleus. Cah-4a expression was restricted mainly to the nervous system, where it was found in nearly all neurons, and recombinant CAH-4A protein could regulate pH in the nucleus. CONCLUSIONS In addition to establishing C. elegans as a platform for studying αCA function, this is the first example of a nuclear-targeted αCA in any organism to date. GENERAL SIGNIFICANCE A classical αCA isoform is targeted exclusively to the nucleus where its activity may impact nuclear physiologic and pathophysiologic responses.
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Affiliation(s)
- Teresa A Sherman
- Department of Medicine, University of Rochester Medical Center, Rochester, NY, USA
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33
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Kaya N, Aldhalaan H, Al-Younes B, Colak D, Shuaib T, Al-Mohaileb F, Al-Sugair A, Nester M, Al-Yamani S, Al-Bakheet A, Al-Hashmi N, Al-Sayed M, Meyer B, Jungbluth H, Al-Owain M. Phenotypical spectrum of cerebellar ataxia associated with a novel mutation in the CA8 gene, encoding carbonic anhydrase (CA) VIII. Am J Med Genet B Neuropsychiatr Genet 2011; 156B:826-34. [PMID: 21812104 DOI: 10.1002/ajmg.b.31227] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 07/12/2011] [Indexed: 11/12/2022]
Abstract
We define the neurological characteristics of familial cases from multiple branches of a large consanguineous family with cerebellar ataxia, mental retardation (MR), and dysequilibrium syndrome type 3 caused by a mutation in the recently cloned CA8 gene. The linkage analysis revealed a high logarithm of the odds (LOD) score region on 8q that harbors the CA8 in which a novel homozygous c.484G>A (p.G162R) mutation was identified in all seven affected members. The patients had variable cerebellar ataxia and mild cognitive impairment without quadrupedal gait. The brain MRI showed variable cerebellar volume loss and ill-defined peritrigonal white matter abnormalities. The Fluorodeoxyglucose Positron Emission Tomography (FDG PET) revealed hypometabolic cerebellar hemispheres, temporal lobes, and mesial cortex. This report expands the neurological and radiological phenotype associated with CA8 mutations. CA8 involvement should be considered in the differential diagnosis of other genetically unresolved autosomal recessive cerebellar ataxias.
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Affiliation(s)
- Namik Kaya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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Puthussery T, Gayet-Primo J, Taylor WR. Carbonic anhydrase-related protein VIII is expressed in rod bipolar cells and alters signaling at the rod bipolar to AII-amacrine cell synapse in the mammalian retina. Eur J Neurosci 2011; 34:1419-31. [PMID: 22004450 DOI: 10.1111/j.1460-9568.2011.07861.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mutation of the gene encoding carbonic anhydrase-related protein VIII (CAVIII) results in motor coordination deficits in mice and humans, due to loss of this protein in Purkinje cells of the cerebellum. Recent studies have indicated that the CAVIII gene, Car8, is also expressed in rod bipolar cells (RBCs), a critical glutamatergic neuron for scotopic vision. We investigated the localization of CAVIII in the mouse and macaque retina, and utilized the wdl mouse, which has a null mutation in the Car8 gene, to determine how the loss of CAVIII affects retinal signaling. CAVIII immunoreactivity was observed in RBCs, with particularly high staining intensity in the axon terminals. In addition, weaker staining was observed in a subset of cone bipolar cells and γ-aminobutyric acid (GABA)ergic amacrine cells. Light-evoked current and voltage responses of RBCs were not altered in the wdl mutant. However, light-evoked current responses from the AII-amacrine cell, a postsynaptic partner at the RBC ribbon synapse, were significantly larger, and more prolonged than in control mice. These changes could not be attributed to alterations in calcium current activation or inactivation, or to changes in the density of RBCs. Furthermore, no gross synaptic alterations were evident in the wdl mutant at the light or ultrastructural level. These data provide evidence that the CAVIII protein, which is highly conserved in vertebrates, is selectively expressed within neural circuits, and may be important for modulating retinal neurotransmission.
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Affiliation(s)
- T Puthussery
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Sciences University, Portland, OR, USA
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35
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Sharp BM, Chen H, Gong S, Wu X, Liu Z, Hiler K, Taylor WL, Matta SG. Gene expression in accumbens GABA neurons from inbred rats with different drug-taking behavior. GENES BRAIN AND BEHAVIOR 2011; 10:778-88. [PMID: 21745336 DOI: 10.1111/j.1601-183x.2011.00716.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Inbred Lewis and Fisher 344 rat strains differ greatly in drug self-administration; Lewis rats operantly self-administer drugs of abuse including nicotine, whereas Fisher self-administer poorly. As shown herein, operant food self-administration is similar. On the basis of their pivotal role in drug reward, we hypothesized that differences in basal gene expression in GABAergic neurons projecting from nucleus accumbens (NAcc) to ventral pallidum (VP) play a role in vulnerability to drug-taking behavior. The transcriptomes of NAcc shell-VP GABAergic neurons from these two strains were analyzed in adolescents, using a multidisciplinary approach that combined stereotaxic ionotophoretic brain microinjections, laser-capture microdissection (LCM) and microarray measurement of transcripts. Laser-capture microdissection enriched the gene transcripts detected in gamma-aminobutyric acid (GABA) neurons compared to the residual NAcc tissue: a ratio of neuron/residual >1 and false discovery rate (FDR) <5% yielded 6623 transcripts, whereas a ratio of >3 yielded 3514. Strain-dependent differences in gene expression within GABA neurons were identified; 322 vs. 60 transcripts showed 1.5-fold vs. 2-fold differences in expression (FDR < 5%). Classification by gene ontology showed that these 322 transcripts were widely distributed, without categorical enrichment. This is most consistent with a global change in GABA neuron function. Literature mining by Chilibot found 38 genes related to synaptic plasticity, signaling and gene transcription, all of which determine drug abuse; 33 genes have no known association with addiction or nicotine. In Lewis rats, upregulation of Mint-1, Cask, CamkII , Ncam1, Vsnl1, Hpcal1 and Car8 indicates that these transcripts likely contribute to altered signaling and synaptic function in NAcc GABA projection neurons to VP.
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Affiliation(s)
- B M Sharp
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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36
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Hartmann J, Henning HA, Konnerth A. mGluR1/TRPC3-mediated Synaptic Transmission and Calcium Signaling in Mammalian Central Neurons. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a006726. [PMID: 21441586 DOI: 10.1101/cshperspect.a006726] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Metabotropic glutamate receptors type 1 (mGluR1s) are required for a normal function of the mammalian brain. They are particularly important for synaptic signaling and plasticity in the cerebellum. Unlike ionotropic glutamate receptors that mediate rapid synaptic transmission, mGluR1s produce in cerebellar Purkinje cells a complex postsynaptic response consisting of two distinct signal components, namely a local dendritic calcium signal and a slow excitatory postsynaptic potential. The basic mechanisms underlying these synaptic responses were clarified in recent years. First, the work of several groups established that the dendritic calcium signal results from IP(3) receptor-mediated calcium release from internal stores. Second, it was recently found that mGluR1-mediated slow excitatory postsynaptic potentials are mediated by the transient receptor potential channel TRPC3. This surprising finding established TRPC3 as a novel postsynaptic channel for glutamatergic synaptic transmission.
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Affiliation(s)
- Jana Hartmann
- Institute of Neuroscience and Center for Integrated Protein Science, Technical University of Munich, Germany.
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37
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LeDoux MS. Animal models of dystonia: Lessons from a mutant rat. Neurobiol Dis 2010; 42:152-61. [PMID: 21081162 DOI: 10.1016/j.nbd.2010.11.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/15/2010] [Accepted: 11/09/2010] [Indexed: 01/25/2023] Open
Abstract
Dystonia is a motor sign characterized by involuntary muscle contractions which produce abnormal postures. Genetic factors contribute significantly to primary dystonia. In comparison, secondary dystonia can be caused by a wide variety of metabolic, structural, infectious, toxic and inflammatory insults to the nervous system. Although classically ascribed to dysfunction of the basal ganglia, studies of diverse animal models have pointed out that dystonia is a network disorder with important contributions from abnormal olivocerebellar signaling. In particular, work with the dystonic (dt) rat has engendered dramatic paradigm shifts in dystonia research. The dt rat manifests generalized dystonia caused by deficiency of the neuronally restricted protein caytaxin. Electrophysiological and biochemical studies have shown that defects at the climbing fiber-Purkinje cell synapse in the dt rat lead to abnormal bursting firing patterns in the cerebellar nuclei, which increases linearly with postnatal age. In a general sense, the dt rat has shown the scientific and clinical communities that dystonia can arise from dysfunctional cerebellar cortex. Furthermore, work with the dt rat has provided evidence that dystonia (1) is a neurodevelopmental network disorder and (2) can be driven by abnormal cerebellar output. In large part, work with other animal models has expanded upon studies in the dt rat and shown that primary dystonia is a multi-nodal network disorder associated with defective sensorimotor integration. In addition, experiments in genetically engineered models have been used to examine the underlying cellular pathologies that drive primary dystonia. This article is part of a Special Issue entitled "Advances in dystonia".
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Affiliation(s)
- Mark S LeDoux
- University of Tennessee Health Science Center, Department of Neurology, 855 Monroe Avenue, Link Building, Suite 415, Memphis, TN 38163, USA.
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38
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Xu X, Kedlaya R, Higuchi H, Ikeda S, Justice MJ, Setaluri V, Ikeda A. Mutation in archain 1, a subunit of COPI coatomer complex, causes diluted coat color and Purkinje cell degeneration. PLoS Genet 2010; 6:e1000956. [PMID: 20502676 PMCID: PMC2873907 DOI: 10.1371/journal.pgen.1000956] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 04/19/2010] [Indexed: 11/18/2022] Open
Abstract
Intracellular trafficking is critical for delivering molecules and organelles to their proper destinations to carry out normal cellular functions. Disruption of intracellular trafficking has been implicated in the pathogenesis of various neurodegenerative disorders. In addition, a number of genes involved in vesicle/organelle trafficking are also essential for pigmentation, and loss of those genes is often associated with mouse coat-color dilution and human hypopigmentary disorders. Hence, we postulated that screening for mouse mutants with both neurological defects and coat-color dilution will help identify additional factors associated with intracellular trafficking in neuronal cells. In this study, we characterized a mouse mutant with a unique N-ethyl-N-nitrosourea (ENU)-induced mutation, named nur17. nur17 mutant mice exhibit both coat-color dilution and ataxia due to Purkinje cell degeneration in the cerebellum. By positional cloning, we identified that the nur17 mouse carries a T-to-C missense mutation in archain 1 (Arcn1) gene which encodes the delta subunit of the coat protein I (COPI) complex required for intracellular trafficking. Consistent with this function, we found that intracellular trafficking is disrupted in nur17 melanocytes. Moreover, the nur17 mutation leads to common characteristics of neurodegenerative disorders such as abnormal protein accumulation, ER stress, and neurofibrillary tangles. Our study documents for the first time the physiological consequences of the impairment of the ARCN1 function in the whole animal and demonstrates a direct association between ARCN1 and neurodegeneration.
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Affiliation(s)
- Xinjie Xu
- Department of Medical Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Rajendra Kedlaya
- Department of Dermatology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Hitoshi Higuchi
- Department of Medical Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Monica J. Justice
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Vijayasaradhi Setaluri
- Department of Dermatology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
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Schorge S, van de Leemput J, Singleton A, Houlden H, Hardy J. Human ataxias: a genetic dissection of inositol triphosphate receptor (ITPR1)-dependent signaling. Trends Neurosci 2010; 33:211-9. [PMID: 20226542 PMCID: PMC4684264 DOI: 10.1016/j.tins.2010.02.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 02/17/2010] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
A persistent mystery about the ataxias has been why mutations in genes--many of which are expressed widely in the brain--primarily cause ataxia, and not, for example, epilepsy or dementia. Why should a polyglutamine stretch in the TATA-binding protein (that is important in all cells) particularly disrupt cerebellar coordination? We propose that advances in the genetics of cerebellar ataxias suggest a rational hypothesis for how so many different genes lead to predominantly cerebellar defects. We argue that the unifying feature of many genes involved in cerebellar ataxias is their impact on the signaling protein ITPR1 (inositiol 1,4,5-triphosphate receptor type 1), that underlies coincidence detection in Purkinje cells and could play an important role in cerebellar coordination.
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Affiliation(s)
- Stephanie Schorge
- Reta Lila Weston Laboratories and Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
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40
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Foskett JK. Inositol trisphosphate receptor Ca2+ release channels in neurological diseases. Pflugers Arch 2010; 460:481-94. [PMID: 20383523 DOI: 10.1007/s00424-010-0826-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 03/09/2010] [Accepted: 03/11/2010] [Indexed: 01/15/2023]
Abstract
The modulation of cytoplasmic Ca2+ concentration by release from internal stores through the inositol trisphosphate receptor (InsP3R) Ca2+ release channel is a ubiquitous signaling system involved in the regulation of numerous processes. Because of its ubiquitous expression and roles in regulating diverse cell physiological processes, it is not surprising that the InsP3R has been implicated in a number of disease states. However, relatively few mutations in InsP3R genes have been identified to date. Here, I will discuss mutations in the type 1 InsP3R that have been discovered by analyses of human patients and mice with neurological disorders. In addition, I will highlight diseases caused by mutations in other genes, including Huntington's and Alzheimer's diseases and some spinocerebellar ataxias, where the mutant proteins have been found to exert strong influences on InsP3R function that may link InsP3R to disease pathogenesis.
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Affiliation(s)
- J Kevin Foskett
- Department of Physiology, University of Pennsylvania School of Medicine, B39 Anatomy-Chemistry Bldg., 414 Guardian Dr., Philadelphia, PA 19104, USA.
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41
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Aspatwar A, Tolvanen ME, Parkkila S. Phylogeny and expression of carbonic anhydrase-related proteins. BMC Mol Biol 2010; 11:25. [PMID: 20356370 PMCID: PMC2873310 DOI: 10.1186/1471-2199-11-25] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 03/31/2010] [Indexed: 12/20/2022] Open
Abstract
Background Carbonic anhydrases (CAs) are found in many organisms, in which they contribute to several important biological processes. The vertebrate α-CA family consists of 16 subfamilies, three of which (VIII, X and XI) consist of acatalytic proteins. These are named carbonic anhydrase related proteins (CARPs), and their inactivity is due to absence of one or more Zn-binding histidine residues. In this study, we analyzed and evaluated the distribution of genes encoding CARPs in different organisms using bioinformatic methods, and studied their expression in mouse tissues using immunohistochemistry and real-time quantitative PCR. Results We collected 84 sequences, of which 22 came from novel or improved gene models which we created from genome data. The distribution of CARP VIII covers vertebrates and deuterostomes, and CARP X appears to be universal in the animal kingdom. CA10-like genes have had a separate history of duplications in the tetrapod and fish lineages. Our phylogenetic analysis showed that duplication of CA10 into CA11 has occurred only in tetrapods (found in mammals, frogs, and lizards), whereas an independent duplication of CA10 was found in fishes. We suggest the name CA10b for the second fish isoform. Immunohistochemical analysis showed a high expression level of CARP VIII in the mouse cerebellum, cerebrum, and also moderate expression in the lung, liver, salivary gland, and stomach. These results also demonstrated low expression in the colon, kidney, and Langerhans islets. CARP X was moderately expressed in the cerebral capillaries and the lung and very weakly in the stomach and heart. Positive signals for CARP XI were observed in the cerebellum, cerebrum, liver, stomach, small intestine, colon, kidney, and testis. In addition, the results of real-time quantitative PCR confirmed a wide distribution for the Car8 and Car11 mRNAs, whereas the expression of the Car10 mRNA was restricted to the frontal cortex, parietal cortex, cerebellum, midbrain, and eye. Conclusions CARP sequences have been strongly conserved between different species, and all three CARPs show high expression in the mouse brain and CARP VIII is also expressed in several other tissues. These findings suggest an important functional role for these proteins in mammals.
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Affiliation(s)
- Ashok Aspatwar
- Bioinformatics Group, Institute of Medical Technology, 33014 University of Tampere, Tampere, Finland.
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42
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Türkmen S, Guo G, Garshasbi M, Hoffmann K, Alshalah AJ, Mischung C, Kuss A, Humphrey N, Mundlos S, Robinson PN. CA8 mutations cause a novel syndrome characterized by ataxia and mild mental retardation with predisposition to quadrupedal gait. PLoS Genet 2009; 5:e1000487. [PMID: 19461874 PMCID: PMC2677160 DOI: 10.1371/journal.pgen.1000487] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 04/21/2009] [Indexed: 12/21/2022] Open
Abstract
We describe a consanguineous Iraqi family in which affected siblings had mild mental retardation and congenital ataxia characterized by quadrupedal gait. Genome-wide linkage analysis identified a 5.8 Mb interval on chromosome 8q with shared homozygosity among the affected persons. Sequencing of genes contained in the interval revealed a homozygous mutation, S100P, in carbonic anhydrase related protein 8 (CA8), which is highly expressed in cerebellar Purkinje cells and influences inositol triphosphate (ITP) binding to its receptor ITPR1 on the endoplasmatic reticulum and thereby modulates calcium signaling. We demonstrate that the mutation S100P is associated with proteasome-mediated degradation, and thus presumably represents a null mutation comparable to the Ca8 mutation underlying the previously described waddles mouse, which exhibits ataxia and appendicular dystonia. CA8 thus represents the third locus that has been associated with quadrupedal gait in humans, in addition to the VLDLR locus and a locus at chromosome 17p. Our findings underline the importance of ITP-mediated signaling in cerebellar function and provide suggestive evidence that congenital ataxia paired with cerebral dysfunction may, together with unknown contextual factors during development, predispose to quadrupedal gait in humans. We identified a homozygous missense mutation (S100P) in the gene encoding carbonic anhydrase VIII in a consanguineous Iraqi family in which affected siblings had mild mental retardation and congenital ataxia characterized by quadrupedal gait. The affected persons walk on their hands and feet with their legs held straight with a “bear-like” gait. Our results show that the mutation S100P induces proteasome-mediated degradation with a severe reduction of the level of CA8 protein. The waddles (wdl) mouse, a spontaneous animal model with ataxia, was previously shown to harbor a 19-bp deletion in Ca8 that leads to an almost complete lack of detectable Ca8 protein, resulting in abnormalities in cerebellar synaptic transmission. Therefore, we speculate that the reduction in CA8 protein concentration associated with the S100P mutation could result in similar pathophysiological effects. With the current report, alterations at three gene loci (CA8, VLDLR, and a yet-to-be discovered gene on chromosome 17p) have been reported to be associated with quadrupedal gait. It is unknown whether quadrupedal gait is related to specific molecular abnormalities or is an adaptive response to ataxia in some circumstances. However, we note that ataxia associated with mutations at all three loci is congenital and also associated with mental retardation, which is not generally a feature of other hereditary ataxias.
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MESH Headings
- Ataxia/congenital
- Ataxia/genetics
- Ataxia/physiopathology
- Base Sequence
- Biomarkers, Tumor/deficiency
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/physiology
- Cerebellar Ataxia/congenital
- Cerebellar Ataxia/genetics
- Cerebellar Ataxia/physiopathology
- Consanguinity
- DNA Primers/genetics
- Enzyme Stability
- Female
- Gait Ataxia/congenital
- Gait Ataxia/genetics
- Gait Ataxia/physiopathology
- Gait Disorders, Neurologic/genetics
- Gait Disorders, Neurologic/physiopathology
- Haplotypes
- Homozygote
- Humans
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Intellectual Disability/genetics
- Iraq
- Male
- Mutation, Missense
- Pedigree
- Signal Transduction
- Syndrome
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Affiliation(s)
- Seval Türkmen
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Gao Guo
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Masoud Garshasbi
- Max Planck Institute for Molecular Genetics, Berlin, Germany
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Katrin Hoffmann
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Claudia Mischung
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Andreas Kuss
- Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Nicholas Humphrey
- Centre for Philosophy of Natural and Social Science, London School of Economics, London, United Kingdom
| | - Stefan Mundlos
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Max Planck Institute for Molecular Genetics, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany
| | - Peter N. Robinson
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany
- * E-mail:
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Watanabe M. Molecular Mechanisms Governing Competitive Synaptic Wiring in Cerebellar Purkinje Cells. TOHOKU J EXP MED 2008; 214:175-90. [DOI: 10.1620/tjem.214.175] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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