1
|
Tang J, Huang X. Transcriptome analysis of human dental pulp cells cultured on a novel cell-adhesive fragment by RNA sequencing. Gene 2024; 927:148709. [PMID: 38901533 DOI: 10.1016/j.gene.2024.148709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/09/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
AIM The aim of the present work was to find an efficient method for safe and reliable expansion of human dental pulp cells (hDPCs) in vitro. Here, we examined the effect of a novel recombinant E8 fragment of Laminin-511 (iMatrix-511) in hDPCs regarding viability and cell spreading. Further, we investigated the underlying mechanisms governing its effects in hDPCs using RNA sequencing (RNA-seq). METHODOLOGY hDPCs were obtained from caries-free maxilla third molars (n = 3). CCK-8 assay was conducted to measure the viability of cells cultured on iMatrix-511 and two other ECM proteins. Cell morphology was observed by phase contrast microscope. RNA-seq of hDPCs cultured on iMatrix-511 or noncoated control was performed on Illumina NovaseqTM 6000 platform. RESULTS iMatrix-511 (0.5 μg/cm2) enhanced the viability of hDPCs to an extent better than COL-1 and gelatin. Short term culture of hDPCs on iMatrix-511 resulted in 233 differentially expressed genes (DEGs). The top 12 most upregulated genes were XIAP, AL354740, MRFAP1, AC012321, KCND3, TMEM120B, AC009812, GET1-SH3BGR, CNTN3, AC090409, GEN1 and PIK3IP1, whereas the top 12 most downregulated genes were SFN, KRT17, RAB4B-EGLN2, CSTA, KCTD11, ATP6V1G2-DDX39B, AC010323, SBSN, LYPD3, FOSB, AC022400 and CHI3L1. qPCR validation confirmed the significant upregulation of GEN1, KCND3, PIK3IP1 and MRFAP1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed, with genes enriched in various extracellular matrix interaction, estrogen and fat metabolism-related functions and pathways. CONCLUSIONS iMatrix-511 facilitated spreading and proliferation of hDPCs. It enhances expression of anti-apoptotic genes, while inhibits expression of epidermis development-related genes.
Collapse
Affiliation(s)
- Jia Tang
- School and Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, Shanghai 200072, PR China
| | - Xiaofeng Huang
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, PR China.
| |
Collapse
|
2
|
Egido-Betancourt HX, Strowd Iii RE, Raab-Graham KF. Potential roles of voltage-gated ion channel disruption in Tuberous Sclerosis Complex. Front Mol Neurosci 2024; 17:1404884. [PMID: 39253727 PMCID: PMC11381416 DOI: 10.3389/fnmol.2024.1404884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 06/27/2024] [Indexed: 09/11/2024] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a lynchpin disorder, as it results in overactive mammalian target of rapamycin (mTOR) signaling, which has been implicated in a multitude of disease states. TSC is an autosomal dominant disease where 90% of affected individuals develop epilepsy. Epilepsy results from aberrant neuronal excitability that leads to recurring seizures. Under neurotypical conditions, the coordinated activity of voltage-gated ion channels keep neurons operating in an optimal range, thus providing network stability. Interestingly, loss or gain of function mutations in voltage-gated potassium, sodium, or calcium channels leads to altered excitability and seizures. To date, little is known about voltage-gated ion channel expression and function in TSC. However, data is beginning to emerge on how mTOR signaling regulates voltage-gated ion channel expression in neurons. Herein, we provide a comprehensive review of the literature describing common seizure types in patients with TSC, and suggest possible parallels between acquired epilepsies with known voltage-gated ion channel dysfunction. Furthermore, we discuss possible links toward mTOR regulation of voltage-gated ion channels expression and channel kinetics and the underlying epileptic manifestations in patients with TSC.
Collapse
Affiliation(s)
- Hailey X Egido-Betancourt
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Roy E Strowd Iii
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Kimberly F Raab-Graham
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| |
Collapse
|
3
|
Liu L, Ren D, Li K, Ji L, Feng M, Li Z, Meng L, He G, Shi Y. Unraveling schizophrenia's genetic complexity through advanced causal inference and chromatin 3D conformation. Schizophr Res 2024; 270:476-485. [PMID: 38996525 DOI: 10.1016/j.schres.2024.07.005] [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: 01/18/2024] [Revised: 07/01/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024]
Abstract
Schizophrenia is a polygenic complex disease with a heritability as high as 80 %, yet the mechanism of polygenic interaction in its pathogenesis remains unclear. Studying the interaction and regulation of schizophrenia susceptibility genes is crucial for unraveling the pathogenesis of schizophrenia and developing antipsychotic drugs. Therefore, we developed a bioinformatics method named GRACI (Gene Regulation Analysis based on Causal Inference) based on the principles of information theory, a causal inference model, and high order chromatin 3D conformation. GRACI captures the interaction and regulatory relationships between schizophrenia susceptibility genes by analyzing genotyping data. Two datasets, comprising 1459 and 2065 samples respectively, were analyzed, and the gene networks from both datasets were constructed. GRACI showcased superior accuracy when compared to widely adopted methods for detecting gene-gene interactions and intergenic regulation. This alignment was further substantiated by its correlation with chromatin high-order conformation patterns. Using GRACI, we identified three potential genes-KCNN3, KCNH1, and KCND3-that are directly associated with schizophrenia pathogenesis. Furthermore, the results of GRACI on the standalone dataset illustrated the method's applicability to other complex diseases. GRACI download: https://github.com/liuliangjie19/GRACI.
Collapse
Affiliation(s)
- Liangjie Liu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Decheng Ren
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Keyi Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Lei Ji
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Mofan Feng
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Zhuoheng Li
- Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, MI 48109, USA
| | - Luming Meng
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510630, China
| | - Guang He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Yi Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Research Institute for Doping Control, Shanghai University of Sport, Shanghai 200438, China.
| |
Collapse
|
4
|
Reis MC, Mandler L, Kang J, Oliver D, Halaszovich C, Nolte D. A novel KCND3 variant in the N-terminus impairs the ionic current of Kv4.3 and is associated with SCA19/22. J Cell Mol Med 2024; 28:e70039. [PMID: 39180521 PMCID: PMC11344468 DOI: 10.1111/jcmm.70039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 07/05/2024] [Indexed: 08/26/2024] Open
Abstract
Spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of autosomal dominant movement disorders. Among the SCAs associated with impaired ion channel function, SCA19/22 is caused by pathogenic variants in KCND3, which encodes the voltage-gated potassium channel Kv4.3. SCA19/22 is clinically characterized by ataxia, dysarthria and oculomotor dysfunction in combination with other signs and symptoms, including mild cognitive impairment, peripheral neuropathy and pyramidal signs. The known KCND3 pathogenic variants are localized either in the transmembrane segments, the connecting loops, or the C-terminal region of Kv4.3. We have identified a novel pathogenic variant, c.455A>G (p.D152G), localized in the N-terminus of Kv4.3. It is located in the immediate neighbourhood of the T1 domain, which is responsible for multimerization with the β-subunit KChIP2b and thus for the formation of functional heterooctamers. Electrophysiological studies showed that p.D152G does not affect channel gating, but reduces the ionic current in Kv4.3, even though the variant is not located in the transmembrane domains. Impaired channel trafficking to the plasma membrane may contribute to this effect. In a patient with a clinical picture corresponding to SCA19/22, p.D152G is the first pathogenic variant in the N-terminus of Kv4.3 to be described to date with an effect on ion channel activity.
Collapse
Affiliation(s)
| | - Laura Mandler
- Institute of Human GeneticsJustus‐Liebig‐University GiessenGiessenGermany
- Present address:
Department of NeurologyJustus‐Liebig‐University GiessenGiessenGermany
| | - Jun‐Suk Kang
- Department of NeurologyGoethe‐University FrankfurtFrankfurtGermany
- Present address:
NeuropraxisFrankfurtGermany
| | - Dominik Oliver
- Institute of PhysiologyPhilipps‐University MarburgMarburgGermany
| | | | - Dagmar Nolte
- Institute of Human GeneticsJustus‐Liebig‐University GiessenGiessenGermany
| |
Collapse
|
5
|
Bhat S, Rousseau J, Michaud C, Lourenço CM, Stoler JM, Louie RJ, Clarkson LK, Lichty A, Koboldt DC, Reshmi SC, Sisodiya SM, Hoytema van Konijnenburg EMM, Koop K, van Hasselt PM, Démurger F, Dubourg C, Sullivan BR, Hughes SS, Thiffault I, Tremblay ES, Accogli A, Srour M, Blunck R, Campeau PM. Mono-allelic KCNB2 variants lead to a neurodevelopmental syndrome caused by altered channel inactivation. Am J Hum Genet 2024; 111:761-777. [PMID: 38503299 PMCID: PMC11023922 DOI: 10.1016/j.ajhg.2024.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 02/23/2024] [Accepted: 02/25/2024] [Indexed: 03/21/2024] Open
Abstract
Ion channels mediate voltage fluxes or action potentials that are central to the functioning of excitable cells such as neurons. The KCNB family of voltage-gated potassium channels (Kv) consists of two members (KCNB1 and KCNB2) encoded by KCNB1 and KCNB2, respectively. These channels are major contributors to delayed rectifier potassium currents arising from the neuronal soma which modulate overall excitability of neurons. In this study, we identified several mono-allelic pathogenic missense variants in KCNB2, in individuals with a neurodevelopmental syndrome with epilepsy and autism in some individuals. Recurrent dysmorphisms included a broad forehead, synophrys, and digital anomalies. Additionally, we selected three variants where genetic transmission has not been assessed, from two epilepsy studies, for inclusion in our experiments. We characterized channel properties of these variants by expressing them in oocytes of Xenopus laevis and conducting cut-open oocyte voltage clamp electrophysiology. Our datasets indicate no significant change in absolute conductance and conductance-voltage relationships of most disease variants as compared to wild type (WT), when expressed either alone or co-expressed with WT-KCNB2. However, variants c.1141A>G (p.Thr381Ala) and c.641C>T (p.Thr214Met) show complete abrogation of currents when expressed alone with the former exhibiting a left shift in activation midpoint when expressed alone or with WT-KCNB2. The variants we studied, nevertheless, show collective features of increased inactivation shifted to hyperpolarized potentials. We suggest that the effects of the variants on channel inactivation result in hyper-excitability of neurons, which contributes to disease manifestations.
Collapse
Affiliation(s)
- Shreyas Bhat
- Center for Interdisciplinary Research on Brain and Learning (CIRCA), Department of Physics and Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, Canada
| | - Justine Rousseau
- Centre de Recherche Du Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC H3T 1C5, Canada
| | - Coralie Michaud
- Centre de Recherche Du Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC H3T 1C5, Canada
| | | | - Joan M Stoler
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | | | | | - Angie Lichty
- Greenwood Genetic Center, Greenwood, SC 29646, USA
| | - Daniel C Koboldt
- Steve and Cindy Rasmussen Institute for Genomic Medicine at Nationwide Children's Hospital, Columbus, OH, USA
| | - Shalini C Reshmi
- Steve and Cindy Rasmussen Institute for Genomic Medicine at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London WC1N 3BG, UK
| | | | - Klaas Koop
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Peter M van Hasselt
- Department of Genetics, Section Metabolic Diagnostics, University Medical Center Utrecht, Utrecht, the Netherlands
| | | | - Christèle Dubourg
- Department of Molecular Genetics and Genomics, Rennes University Hospital, Rennes, France; Université de Rennes, CNRS, IGDR, UMR 6290 Rennes, France
| | - Bonnie R Sullivan
- Division of Clinical Genetics, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO, USA
| | - Susan S Hughes
- Division of Clinical Genetics, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, MO, USA
| | - Isabelle Thiffault
- Departments of Pediatrics and of Pathology and Laboratory Medicine, Children's Mercy Kansas City, Kansas City, MO, USA
| | - Elisabeth Simard Tremblay
- Department of Neurology and Neurosurgery, McGill University Health Centre, Montréal, QC, Canada; Department of Pediatrics, Division of Pediatric Neurology, McGill University, Montréal, QC, Canada
| | - Andrea Accogli
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre, Montréal, QC, Canada; Department of Human Genetics, Faculty of Medicine, McGill University, Montral, QC H3A 1B1, Canada
| | - Myriam Srour
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, Montréal, QC, Canada; Department of Human Genetics, Faculty of Medicine, McGill University, Montral, QC H3A 1B1, Canada
| | - Rikard Blunck
- Center for Interdisciplinary Research on Brain and Learning (CIRCA), Department of Physics and Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, Canada.
| | | |
Collapse
|
6
|
Khan R, Chaturvedi P, Sahu P, Ludhiadch A, Singh P, Singh G, Munshi A. Role of Potassium Ion Channels in Epilepsy: Focus on Current Therapeutic Strategies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:67-87. [PMID: 36578258 DOI: 10.2174/1871527322666221227112621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Epilepsy is one of the prevalent neurological disorders characterized by disrupted synchronization between inhibitory and excitatory neurons. Disturbed membrane potential due to abnormal regulation of neurotransmitters and ion transport across the neural cell membrane significantly contributes to the pathophysiology of epilepsy. Potassium ion channels (KCN) regulate the resting membrane potential and are involved in neuronal excitability. Genetic alterations in the potassium ion channels (KCN) have been reported to result in the enhancement of the release of neurotransmitters, the excitability of neurons, and abnormal rapid firing rate, which lead to epileptic phenotypes, making these ion channels a potential therapeutic target for epilepsy. The aim of this study is to explore the variations reported in different classes of potassium ion channels (KCN) in epilepsy patients, their functional evaluation, and therapeutic strategies to treat epilepsy targeting KCN. METHODOLOGY A review of all the relevant literature was carried out to compile this article. RESULTS A large number of variations have been reported in different genes encoding various classes of KCN. These genetic alterations in KCN have been shown to be responsible for disrupted firing properties of neurons. Antiepileptic drugs (AEDs) are the main therapeutic strategy to treat epilepsy. Some patients do not respond favorably to the AEDs treatment, resulting in pharmacoresistant epilepsy. CONCLUSION Further to address the challenges faced in treating epilepsy, recent approaches like optogenetics, chemogenetics, and genome editing, such as clustered regularly interspaced short palindromic repeats (CRISPR), are emerging as target-specific therapeutic strategies.
Collapse
Affiliation(s)
- Rahul Khan
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Pragya Chaturvedi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Prachi Sahu
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Abhilash Ludhiadch
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, 151001 India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| |
Collapse
|
7
|
Ågren R, Geerdink N, Brunner HG, Paucar M, Kamsteeg EJ, Sahlholm K. An E280K Missense Variant in KCND3/Kv4.3-Case Report and Functional Characterization. Int J Mol Sci 2023; 24:10924. [PMID: 37446101 DOI: 10.3390/ijms241310924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
A five-year-old girl presented with headache attacks, clumsiness, and a history of transient gait disturbances. She and her father, mother, twin sister, and brother underwent neurological evaluation, neuroimaging, and exome sequencing covering 357 genes associated with movement disorders. Sequencing revealed the new variant KCND3 c.838G>A, p.E280K in the father and sisters, but not in the mother and brother. KCND3 encodes voltage-gated potassium channel D3 (Kv4.3) and mutations have been associated with spinocerebellar ataxia type 19/22 (SCA19/22) and cardiac arrhythmias. SCA19/22 is characterized by ataxia, Parkinsonism, peripheral neuropathy, and sometimes, intellectual disability. Neuroimaging, EEG, and ECG were unremarkable. Mild developmental delay with impaired fluid reasoning was observed in both sisters, but not in the brother. None of the family members demonstrated ataxia or parkinsonism. In Xenopus oocyte electrophysiology experiments, E280K was associated with a rightward shift in the Kv4.3 voltage-activation relationship of 11 mV for WT/E280K and +17 mV for E280K/E280K relative to WT/WT. Steady-state inactivation was similarly right-shifted. Maximal peak current amplitudes were similar for WT/WT, WT/E280K, and E280K/E280K. Our data indicate that Kv4.3 E280K affects channel activation and inactivation and is associated with developmental delay. However, E280K appears to be relatively benign considering it does not result in overt ataxia.
Collapse
Affiliation(s)
- Richard Ågren
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Niels Geerdink
- Department of Pediatrics, Rijnstate Hospital, 6815 AD Arnhem, The Netherlands
| | - Han G Brunner
- Department of Human Genetics, Donders Centre for Brain, Cognition and Behavior, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Department of Clinical Genetics, MUMC Maastricht, GROW School for Oncology and Developmental Biology, MHENS School for Mental Health and Neuroscience, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
| | - Martin Paucar
- Department of Neurology, Karolinska University Hospital, 141 86 Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud UMC, 6525 GA Nijmegen, The Netherlands
| | - Kristoffer Sahlholm
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Integrative Medical Biology, Wallenberg Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| |
Collapse
|
8
|
Iezzi D, Curti L, Ranieri G, Gerace E, Costa A, Ilari A, La Rocca A, Luceri C, D'Ambrosio M, Silvestri L, Scardigli M, Mannaioni G, Masi A. Acute rapamycin rescues the hyperexcitable phenotype of accumbal medium spiny neurons in the valproic acid rat model of autism spectrum disorder. Pharmacol Res 2022; 183:106401. [PMID: 35987482 DOI: 10.1016/j.phrs.2022.106401] [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: 06/06/2022] [Revised: 08/04/2022] [Accepted: 08/14/2022] [Indexed: 11/17/2022]
Abstract
We previously demonstrated that prenatal exposure to valproic acid (VPA), an environmental model of autism spectrum disorder (ASD), leads to a hyperexcitable phenotype associated with downregulation of inward-rectifying potassium currents in nucleus accumbens (NAc) medium spiny neurons (MSNs) of adolescent rats. Aberrant mTOR pathway function has been associated with autistic-like phenotypes in multiple animal models, including gestational exposure to VPA. The purpose of this work was to probe the involvement of the mTOR pathway in VPA-induced alterations of striatal excitability. Adolescent male Wistar rats prenatally exposed to VPA were treated acutely with the mTOR inhibitor rapamycin and used for behavioral tests, ex vivo brain slice electrophysiology, single-neuron morphometric analysis, synaptic protein quantification and gene expression analysis in the NAc. We report that postnatal rapamycin ameliorates the social deficit and reverts the abnormal excitability, but not the inward-rectifying potassium current defect, of accumbal MSNs. Synaptic transmission and neuronal morphology were largely unaffected by prenatal VPA exposure or postnatal rapamycin treatment. Transcriptome analysis revealed extensive deregulation of genes implied in neurodevelopmental disorders and ionic mechanisms exerted by prenatal VPA, which was partially reverted by postnatal rapamycin. The results of this work support the existence of antagonistic interaction between mTOR and VPA-induced pathways on social behavior, neurophysiological phenotype and gene expression profile, thus prompting further investigation of the mTOR pathway in the quest for specific therapeutic targets in ASD.
Collapse
Affiliation(s)
- D Iezzi
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy; Institut de Neurobiologie de la MEDiterranée - INMED, 163, Avenue de Luminy - Parc Scientifique, 13009, Marseille, France
| | - L Curti
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - G Ranieri
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - E Gerace
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - A Costa
- Università degli Studi di Firenze, Dipartimento di Scienze della Salute, viale Pieraccini 6, 50139, Firenze, Italy
| | - A Ilari
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - A La Rocca
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - C Luceri
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - M D'Ambrosio
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - L Silvestri
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via Sansone 1, 50019, Sesto Fiorentino, Italy; European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - M Scardigli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via Sansone 1, 50019, Sesto Fiorentino, Italy; European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - G Mannaioni
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy
| | - A Masi
- Università degli Studi di Firenze, Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino - NEUROFARBA, viale Pieraccini 6, 50139, Firenze, Italy.
| |
Collapse
|
9
|
Li M, Liu F, Hao X, Fan Y, Li J, Hu Z, Shi J, Fan L, Zhang S, Ma D, Guo M, Xu Y, Shi C. Rare KCND3 Loss-of-Function Mutation Associated With the SCA19/22. Front Mol Neurosci 2022; 15:919199. [PMID: 35813061 PMCID: PMC9261871 DOI: 10.3389/fnmol.2022.919199] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/19/2022] [Indexed: 12/15/2022] Open
Abstract
Spinocerebellar ataxia 19/22 (SCA19/22) is a rare neurodegenerative disorder caused by mutations of the KCND3 gene, which encodes the Kv4. 3 protein. Currently, only 22 KCND3 single-nucleotide mutation sites of SCA19/22 have been reported worldwide, and detailed pathogenesis remains unclear. In this study, Sanger sequencing was used to screen 115 probands of cerebellar ataxia families in 67 patients with sporadic cerebellar ataxia and 200 healthy people to identify KCND3 mutations. Mutant gene products showed pathogenicity damage, and the polarity was changed. Next, we established induced pluripotent stem cells (iPSCs) derived from SCA19/22 patients. Using a transcriptome sequencing technique, we found that protein processing in the endoplasmic reticulum was significantly enriched in SCA19/22-iPS-derived neurons and was closely related to endoplasmic reticulum stress (ERS) and apoptosis. In addition, Western blotting of the SCA19/22-iPS-derived neurons showed a reduction in Kv4.3; but, activation of transcription factor 4 (ATF4) and C/EBP homologous protein was increased. Therefore, the c.1130 C>T (p.T377M) mutation of the KCND3 gene may mediate misfold and aggregation of Kv4.3, which activates the ERS and further induces neuron apoptosis involved in SCA19/22.
Collapse
Affiliation(s)
- Mengjie Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Fen Liu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Xiaoyan Hao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Yu Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Jiadi Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Zhengwei Hu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Jingjing Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Department of Cell Biology and Medical Genetics, Basic Medical College of Zhengzhou University, Zhengzhou, China
| | - Liyuan Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Shuo Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Dongrui Ma
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Mengnan Guo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Yuming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Department of Cell Biology and Medical Genetics, Basic Medical College of Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, China
- The Henan Medical Key Laboratory of Hereditary Neurodegenerative Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- The Key Laboratory of Cerebrovascular Diseases Prevention and Treatment, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Changhe Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, China
- The Henan Medical Key Laboratory of Hereditary Neurodegenerative Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- The Key Laboratory of Cerebrovascular Diseases Prevention and Treatment, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- *Correspondence: Changhe Shi
| |
Collapse
|
10
|
Morrison ME. Virtual/Remote Labs for Fluorescent Immunocytochemistry or Western Blotting: The Next Best Thing to Being There. JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2022; 20:A219-A225. [PMID: 38323057 PMCID: PMC10653236 DOI: 10.59390/xcgj3727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 02/08/2024]
Abstract
The SARS CoV-2 pandemic forced many college courses to convert to remote instruction almost overnight in the middle of the spring 2020 teaching semester. This article presents two molecular biology labs formerly performed in person by students but converted into virtual labs. The virtual immunocytochemistry experiment teaches the specificity of antibody staining, principles of fluorescent microscopy, diversity of brain cell types and morphologies, and journal article Figure construction skills. The virtual Western blotting experiment teaches sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the specificity of antibody binding, and graph creation and interpretation skills. Both virtual experiments use professionally-produced web-based videos of scientists conducting the lab procedures. Students must answer questions about the techniques and analyze real experimental data generated by past students to take a quiz and write a journal article-style lab report. At the whole-class level, student quiz and lab report scores from these virtual labs were not statistically different from those from the in-person versions of the same labs from a previous semester, using t tests with the Bonferroni correction. On the virtual Western blot quiz, students who did the virtual version actually scored higher than students who did the in-person version. These results were significant when the 2020 data were analyzed by within-student paired t tests for in-person labs done before COVID-19 versus those done virtually after dismissal for all-remote instruction. The students learned the laboratory concepts and data analysis skills just as well virtually as their predecessors had in person. However, the students trained virtually reported that they could not enter the lab and actually do Western blotting or fluorescent immunocytochemistry with their own hands without extensive additional training. These virtual experiments can be done with data included in the supplemental materials or can easily be adapted for any micrographs or Western blotting images available from previous lab experiments, or in the published literature. When COVID-19 or other public health emergencies necessitate remote instruction and we can't use the best practice of hands-on lab work, virtual labs can be the next best thing to being there.
Collapse
Affiliation(s)
- Mary E Morrison
- Biology Department and Neuroscience Program, Lycoming College, Williamsport, PA 17701
| |
Collapse
|
11
|
Ye W, Zhao H, Dai Y, Wang Y, Lo YH, Jan LY, Lee CH. Activation and closed-state inactivation mechanisms of the human voltage-gated K V4 channel complexes. Mol Cell 2022; 82:2427-2442.e4. [PMID: 35597238 DOI: 10.1016/j.molcel.2022.04.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/03/2022] [Accepted: 04/24/2022] [Indexed: 12/30/2022]
Abstract
The voltage-gated ion channel activity depends on both activation (transition from the resting state to the open state) and inactivation. Inactivation is a self-restraint mechanism to limit ion conduction and is as crucial to membrane excitability as activation. Inactivation can occur when the channel is open or closed. Although open-state inactivation is well understood, the molecular basis of closed-state inactivation has remained elusive. We report cryo-EM structures of human KV4.2 channel complexes in inactivated, open, and closed states. Closed-state inactivation of KV4 involves an unprecedented symmetry breakdown for pore closure by only two of the four S4-S5 linkers, distinct from known mechanisms of open-state inactivation. We further capture KV4 in a putative resting state, revealing how voltage sensor movements control the pore. Moreover, our structures provide insights regarding channel modulation by KChIP2 and DPP6 auxiliary subunits. Our findings elucidate mechanisms of closed-state inactivation and voltage-dependent activation of the KV4 channel.
Collapse
Affiliation(s)
- Wenlei Ye
- Department of Physiology, University of California, San Francisco, CA 94158, USA
| | - Hongtu Zhao
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yaxin Dai
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yingdi Wang
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yu-Hua Lo
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Lily Yeh Jan
- Department of Physiology, University of California, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA.
| | - Chia-Hsueh Lee
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| |
Collapse
|
12
|
Benarroch E. What Is the Role of Potassium Channels in Ataxia? Neurology 2021; 97:938-941. [PMID: 34782409 DOI: 10.1212/wnl.0000000000012870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 11/15/2022] Open
|
13
|
Rare Gain-of-Function KCND3 Variant Associated with Cerebellar Ataxia, Parkinsonism, Cognitive Dysfunction, and Brain Iron Accumulation. Int J Mol Sci 2021; 22:ijms22158247. [PMID: 34361012 PMCID: PMC8347726 DOI: 10.3390/ijms22158247] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/08/2023] Open
Abstract
Loss-of-function mutations in the KV4.3 channel-encoding KCND3 gene are linked to neurodegenerative cerebellar ataxia. Patients suffering from neurodegeneration associated with iron deposition may also present with cerebellar ataxia. The mechanism underlying brain iron accumulation remains unclear. Here, we aim to ascertain the potential pathogenic role of KCND3 variant in iron accumulation-related cerebellar ataxia. We presented a patient with slowly progressive cerebellar ataxia, parkinsonism, cognitive impairment, and iron accumulation in the basal ganglia and the cerebellum. Whole exome sequencing analyses identified in the patient a heterozygous KCND3 c.1256G>A (p.R419H) variant predicted to be disease-causing by multiple bioinformatic analyses. In vitro biochemical and immunofluorescence examinations revealed that, compared to the human KV4.3 wild-type channel, the p.R419H variant exhibited normal protein abundance and subcellular localization pattern. Electrophysiological investigation, however, demonstrated that the KV4.3 p.R419H variant was associated with a dominant increase in potassium current amplitudes, as well as notable changes in voltage-dependent gating properties leading to enhanced potassium window current. These observations indicate that, in direct contrast with the loss-of-function KCND3 mutations previously reported in cerebellar ataxia patients, we identified a rare gain-of-function KCND3 variant that may expand the clinical and molecular spectra of neurodegenerative cerebellar disorders associated with brain iron accumulation.
Collapse
|
14
|
Xiao Z, Zhao P, Wu X, Kong X, Wang R, Liang S, Tang C, Liu Z. Variation of Two S3b Residues in K V4.1-4.3 Channels Underlies Their Different Modulations by Spider Toxin κ-LhTx-1. Front Pharmacol 2021; 12:692076. [PMID: 34177600 PMCID: PMC8222713 DOI: 10.3389/fphar.2021.692076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/27/2021] [Indexed: 11/13/2022] Open
Abstract
The naturally occurred peptide toxins from animal venoms are valuable pharmacological tools in exploring the structure-function relationships of ion channels. Herein we have identified the peptide toxin κ-LhTx-1 from the venom of spider Pandercetes sp (the Lichen huntsman spider) as a novel selective antagonist of the KV4 family potassium channels. κ-LhTx-1 is a gating-modifier toxin impeded KV4 channels' voltage sensor activation, and mutation analysis has confirmed its binding site on channels' S3b region. Interestingly, κ-LhTx-1 differently modulated the gating of KV4 channels, as revealed by toxin inhibiting KV4.2/4.3 with much more stronger voltage-dependence than that for KV4.1. We proposed that κ-LhTx-1 trapped the voltage sensor of KV4.1 in a much more stable resting state than that for KV4.2/4.3 and further explored the underlying mechanism. Swapping the non-conserved S3b segments between KV4.1(280FVPK283) and KV4.3(275VMTN278) fully reversed their voltage-dependence phenotypes in inhibition by κ-LhTx-1, and intensive mutation analysis has identified P282 in KV4.1, D281 in KV4.2 and N278 in KV4.3 being the key residues. Furthermore, the last two residues in this segment of each KV4 channel (P282/K283 in KV4.1, T280/D281 in KV4.2 and T277/N278 in KV4.3) likely worked synergistically as revealed by our combinatorial mutations analysis. The present study has clarified the molecular basis in KV4 channels for their different modulations by κ-LhTx-1, which have advanced our understanding on KV4 channels' structure features. Moreover, κ-LhTx-1 might be useful in developing anti-arrhythmic drugs given its high affinity, high selectivity and unique action mode in interacting with the KV4.2/4.3 channels.
Collapse
Affiliation(s)
- Zhen Xiao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Piao Zhao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiangyue Wu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiangjin Kong
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Ruiwen Wang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Songping Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Zhonghua Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| |
Collapse
|
15
|
Novel KCND3 Variant Underlying Nonprogressive Congenital Ataxia or SCA19/22 Disrupt K V4.3 Protein Expression and K+ Currents with Variable Effects on Channel Properties. Int J Mol Sci 2021; 22:ijms22094986. [PMID: 34067185 PMCID: PMC8125845 DOI: 10.3390/ijms22094986] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 02/07/2023] Open
Abstract
KCND3 encodes the voltage-gated potassium channel KV4.3 that is highly expressed in the cerebellum, where it regulates dendritic excitability and calcium influx. Loss-of-function KV4.3 mutations have been associated with dominant spinocerebellar ataxia (SCA19/22). By targeted NGS sequencing, we identified two novel KCND3 missense variants of the KV4.3 channel: p.S347W identified in a patient with adult-onset pure cerebellar syndrome and p.W359G detected in a child with congenital nonprogressive ataxia. Neuroimaging showed mild cerebellar atrophy in both patients. We performed a two-electrode voltage-clamp recording of KV4.3 currents in Xenopus oocytes: both the p.G345V (previously reported in a SCA19/22 family) and p.S347W mutants exhibited reduced peak currents by 50%, while no K+ current was detectable for the p.W359G mutant. We assessed the effect of the mutations on channel gating by measuring steady-state voltage-dependent activation and inactivation properties: no significant alterations were detected in p.G345V and p.S347W disease-associated variants, compared to controls. KV4.3 expression studies in HEK293T cells showed 53% (p.G345V), 45% (p.S347W) and 75% (p.W359G) reductions in mutant protein levels compared with the wildtype. The present study broadens the spectrum of the known phenotypes and identifies additional variants for KCND3-related disorders, outlining the importance of SCA gene screening in early-onset and congenital ataxia.
Collapse
|
16
|
Paucar M, Ågren R, Li T, Lissmats S, Bergendal Å, Weinberg J, Nilsson D, Savichetva I, Sahlholm K, Nilsson J, Svenningsson P. V374A KCND3 Pathogenic Variant Associated With Paroxysmal Ataxia Exacerbations. NEUROLOGY-GENETICS 2021; 7:e546. [PMID: 33575485 PMCID: PMC7862093 DOI: 10.1212/nxg.0000000000000546] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/27/2020] [Indexed: 12/27/2022]
Abstract
Objective Ataxia channelopathies share common features such as slow motor progression and variable degrees of cognitive dysfunction. Mutations in potassium voltage-gated channel subfamily D member 3 (KCND3), encoding the K+ channel, Kv4.3, are associated with spinocerebellar ataxia (SCA) 19, allelic with SCA22. Mutations in potassium voltage-gated channel subfamily C member 3 (KCNC3), encoding another K+ channel, Kv3.3, cause SCA13. First, a comprehensive phenotype assessment was carried out in a family with autosomal dominant ataxia harboring 2 genetic variants in KCNC3 and KCND3. To evaluate the physiological impact of these variants on channel currents, in vitro studies were performed. Methods Clinical and psychometric evaluations, neuroimaging, and genotyping of a family (mother and son) affected by ataxia were carried out. Heterozygous and homozygous Kv3.3 A671V and Kv4.3 V374A variants were evaluated in Xenopus laevis oocytes using 2-electrode voltage-clamp. The influence of Kv4 conductance on neuronal activity was investigated computationally using a Purkinje neuron model. Results The main clinical findings were consistent with adult-onset ataxia with cognitive dysfunction and acetazolamide-responsive paroxysmal motor exacerbations in the index case. Despite cognitive deficits, fluorodeoxyglucose (FDG)-PET displayed hypometabolism mainly in the severely atrophic cerebellum. Genetic analyses revealed the new variant c.1121T>C (V374A) in KCND3 and c.2012T>C (A671V) in KCNC3. In vitro electrophysiology experiments on Xenopus oocytes demonstrated that the V374A mutant was nonfunctional when expressed on its own. Upon equal co-expression of wild-type (WT) and V374A channel subunits, Kv4.3 currents were significantly reduced in a dominant negative manner, without alterations of the gating properties of the channel. By contrast, Kv3.3 A671V, when expressed alone, exhibited moderately reduced currents compared with WT, with no effects on channel activation or inactivation. Immunohistochemistry demonstrated adequate cell membrane translocation of the Kv4.3 V374A variant, thus suggesting an impairment of channel function, rather than of expression. Computational modeling predicted an increased Purkinje neuron firing frequency upon reduced Kv4.3 conductance. Conclusions Our findings suggest that Kv4.3 V374A is likely pathogenic and associated with paroxysmal ataxia exacerbations, a new trait for SCA19/22. The present FDG PET findings contrast with a previous study demonstrating widespread brain hypometabolism in SCA19/22.
Collapse
Affiliation(s)
- Martin Paucar
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Richard Ågren
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Tianyi Li
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Simon Lissmats
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Åsa Bergendal
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Jan Weinberg
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Daniel Nilsson
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Irina Savichetva
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Kristoffer Sahlholm
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Johanna Nilsson
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| | - Per Svenningsson
- Department of Clinical Neuroscience (M.P., R.Å., T.L., Å.B., J.N., P.S.), Department of Molecular Medicine and Surgery (D.N.), Center for Molecular Medicine (D.N.), and Science for Life Laboratory (D.N.), Karolinska Institutet (S.L., I.S.), Stockholm; Department of Neurology (M.P., J.W., P.S.), Department of Clinical Genetics (D.N.), Department of Nuclear Medicine (I.S.), and Department of Neurophysiology (J.N.), Karolinska University Hospital (R.Å.), Stockholm; Department of Integrative Medical Biology (K.S.), Umeå University; and Department of Medical Sciences (J.N.), Örebro University, Sweden
| |
Collapse
|
17
|
Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
Collapse
Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| |
Collapse
|
18
|
KCND3-Related Neurological Disorders: From Old to Emerging Clinical Phenotypes. Int J Mol Sci 2020; 21:ijms21165802. [PMID: 32823520 PMCID: PMC7461103 DOI: 10.3390/ijms21165802] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
KCND3 encodes the voltage-gated potassium ion channel subfamily D member 3, a six trans-membrane protein (Kv4.3), involved in the transient outward K+ current. KCND3 defect causes both cardiological and neurological syndromes. From a neurological perspective, Kv4.3 defect has been associated to SCA type 19/22, a complex neurological disorder encompassing a wide spectrum of clinical features beside ataxia. To better define the phenotypic spectrum and course of KCND3-related neurological disorder, we review the clinical presentation and evolution in 68 reported cases. We delineated two main clinical phenotypes according to the age of onset. Neurodevelopmental disorder with epilepsy and/or movement disorders with ataxia later in the disease course characterized the early onset forms, while a prominent ataxic syndrome with possible cognitive decline, movement disorders, and peripheral neuropathy were observed in the late onset forms. Furthermore, we described a 37-year-old patient with a de novo KCND3 variant [c.901T>C (p.Ser301Pro)], previously reported in dbSNP as rs79821338, and a clinical phenotype paradigmatic of the early onset forms with neurodevelopmental disorder, epilepsy, parkinsonism-dystonia, and ataxia in adulthood, further expanding the clinical spectrum of this condition.
Collapse
|
19
|
Inter-Regulation of K v4.3 and Voltage-Gated Sodium Channels Underlies Predisposition to Cardiac and Neuronal Channelopathies. Int J Mol Sci 2020; 21:ijms21145057. [PMID: 32709127 PMCID: PMC7404392 DOI: 10.3390/ijms21145057] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/04/2020] [Accepted: 07/10/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Genetic variants in voltage-gated sodium channels (Nav) encoded by SCNXA genes, responsible for INa, and Kv4.3 channels encoded by KCND3, responsible for the transient outward current (Ito), contribute to the manifestation of both Brugada syndrome (BrS) and spinocerebellar ataxia (SCA19/22). We examined the hypothesis that Kv4.3 and Nav variants regulate each other’s function, thus modulating INa/Ito balance in cardiomyocytes and INa/I(A) balance in neurons. Methods: Bicistronic and other constructs were used to express WT or variant Nav1.5 and Kv4.3 channels in HEK293 cells. INa and Ito were recorded. Results: SCN5A variants associated with BrS reduced INa, but increased Ito. Moreover, BrS and SCA19/22 KCND3 variants associated with a gain of function of Ito, significantly reduced INa, whereas the SCA19/22 KCND3 variants associated with a loss of function (LOF) of Ito significantly increased INa. Auxiliary subunits Navβ1, MiRP3 and KChIP2 also modulated INa/Ito balance. Co-immunoprecipitation and Duolink studies suggested that the two channels interact within the intracellular compartments and biotinylation showed that LOF SCN5A variants can increase Kv4.3 cell-surface expression. Conclusion: Nav and Kv4.3 channels modulate each other’s function via trafficking and gating mechanisms, which have important implications for improved understanding of these allelic cardiac and neuronal syndromes.
Collapse
|
20
|
Kessi M, Chen B, Peng J, Tang Y, Olatoutou E, He F, Yang L, Yin F. Intellectual Disability and Potassium Channelopathies: A Systematic Review. Front Genet 2020; 11:614. [PMID: 32655623 PMCID: PMC7324798 DOI: 10.3389/fgene.2020.00614] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/20/2020] [Indexed: 01/15/2023] Open
Abstract
Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in ID is poorly understood. Therefore, we aimed to evaluate the relationship between ID and potassium channelopathies. We hypothesized that potassium channelopathies are strongly associated with ID initiation, and that both gain- and loss-of-function mutations lead to ID. This systematic review explores the burden of potassium channelopathies, possible mechanisms, advancements using animal models, therapies, and existing gaps. The literature search encompassed both PubMed and Embase up to October 2019. A total of 75 articles describing 338 cases were included in this review. Nineteen channelopathies were identified, affecting the following genes: KCNMA1, KCNN3, KCNT1, KCNT2, KCNJ10, KCNJ6, KCNJ11, KCNA2, KCNA4, KCND3, KCNH1, KCNQ2, KCNAB1, KCNQ3, KCNQ5, KCNC1, KCNB1, KCNC3, and KCTD3. Twelve of these genes presented both gain- and loss-of-function properties, three displayed gain-of-function only, three exhibited loss-of-function only, and one had unknown function. How gain- and loss-of-function mutations can both lead to ID remains largely unknown. We identified only a few animal studies that focused on the mechanisms of ID in relation to potassium channelopathies and some of the few available therapeutic options (channel openers or blockers) appear to offer limited efficacy. In conclusion, potassium channelopathies contribute to the initiation of ID in several instances and this review provides a comprehensive overview of which molecular players are involved in some of the most prominent disease phenotypes.
Collapse
Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China.,Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Mawenzi Regional Referral Hospital, Moshi, Tanzania
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Yulin Tang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Eleonore Olatoutou
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| |
Collapse
|
21
|
Loss-of-function BK channel mutation causes impaired mitochondria and progressive cerebellar ataxia. Proc Natl Acad Sci U S A 2020; 117:6023-6034. [PMID: 32132200 DOI: 10.1073/pnas.1920008117] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Despite a growing number of ion channel genes implicated in hereditary ataxia, it remains unclear how ion channel mutations lead to loss-of-function or death of cerebellar neurons. Mutations in the gene KCNMA1, encoding the α-subunit of the BK channel have emerged as responsible for a variety of neurological phenotypes. We describe a mutation (BKG354S) in KCNMA1, in a child with congenital and progressive cerebellar ataxia with cognitive impairment. The mutation in the BK channel selectivity filter dramatically reduced single-channel conductance and ion selectivity. The BKG354S channel trafficked normally to plasma, nuclear, and mitochondrial membranes, but caused reduced neurite outgrowth, cell viability, and mitochondrial content. Small interfering RNA (siRNA) knockdown of endogenous BK channels had similar effects. The BK activator, NS1619, rescued BKG354S cells but not siRNA-treated cells, by selectively blocking the mutant channels. When expressed in cerebellum via adenoassociated virus (AAV) viral transfection in mice, the mutant BKG354S channel, but not the BKWT channel, caused progressive impairment of several gait parameters consistent with cerebellar dysfunction from 40- to 80-d-old mice. Finally, treatment of the patient with chlorzoxazone, a BK/SK channel activator, partially improved motor function, but ataxia continued to progress. These studies indicate that a loss-of-function BK channel mutation causes ataxia and acts by reducing mitochondrial and subsequently cellular viability.
Collapse
|
22
|
Jenkins CA, Kalmar L, Matiasek K, Mari L, Kyöstilä K, Lohi H, Schofield EC, Mellersh CS, De Risio L, Ricketts SL. Characterisation of canine KCNIP4: A novel gene for cerebellar ataxia identified by whole-genome sequencing two affected Norwegian Buhund dogs. PLoS Genet 2020; 16:e1008527. [PMID: 31999692 PMCID: PMC7012447 DOI: 10.1371/journal.pgen.1008527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/11/2020] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
A form of hereditary cerebellar ataxia has recently been described in the Norwegian Buhund dog breed. This study aimed to identify the genetic cause of the disease. Whole-genome sequencing of two Norwegian Buhund siblings diagnosed with progressive cerebellar ataxia was carried out, and sequences compared with 405 whole genome sequences of dogs of other breeds to filter benign common variants. Nine variants predicted to be deleterious segregated among the genomes in concordance with an autosomal recessive mode of inheritance, only one of which segregated within the breed when genotyped in additional Norwegian Buhunds. In total this variant was assessed in 802 whole genome sequences, and genotyped in an additional 505 unaffected dogs (including 146 Buhunds), and only four affected Norwegian Buhunds were homozygous for the variant. The variant identified, a T to C single nucleotide polymorphism (SNP) (NC_006585.3:g.88890674T>C), is predicted to cause a tryptophan to arginine substitution in a highly conserved region of the potassium voltage-gated channel interacting protein KCNIP4. This gene has not been implicated previously in hereditary ataxia in any species. Evaluation of KCNIP4 protein expression through western blot and immunohistochemical analysis using cerebellum tissue of affected and control dogs demonstrated that the mutation causes a dramatic reduction of KCNIP4 protein expression. The expression of alternative KCNIP4 transcripts within the canine cerebellum, and regional differences in KCNIP4 protein expression, were characterised through RT-PCR and immunohistochemistry respectively. The voltage-gated potassium channel protein KCND3 has previously been implicated in spinocerebellar ataxia, and our findings suggest that the Kv4 channel complex KCNIP accessory subunits also have an essential role in voltage-gated potassium channel function in the cerebellum and should be investigated as potential candidate genes for cerebellar ataxia in future studies in other species.
Collapse
Affiliation(s)
| | - Lajos Kalmar
- Department of Veterinary Medicine, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom
| | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität Munich, München, Germany
| | - Lorenzo Mari
- Neurology/Neurosurgery Service, Centre for Small Animal Studies, Animal Health Trust, Newmarket, Suffolk, United Kingdom
| | - Kaisa Kyöstilä
- Department of Veterinary Biosciences, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
| | - Hannes Lohi
- Department of Veterinary Biosciences, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
| | - Ellen C. Schofield
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, Suffolk, United Kingdom
| | - Cathryn S. Mellersh
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, Suffolk, United Kingdom
| | - Luisa De Risio
- Neurology/Neurosurgery Service, Centre for Small Animal Studies, Animal Health Trust, Newmarket, Suffolk, United Kingdom
| | - Sally L. Ricketts
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, Suffolk, United Kingdom
| |
Collapse
|
23
|
Allen NM, Weckhuysen S, Gorman K, King MD, Lerche H. Genetic potassium channel-associated epilepsies: Clinical review of the K v family. Eur J Paediatr Neurol 2020; 24:105-116. [PMID: 31932120 DOI: 10.1016/j.ejpn.2019.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/22/2022]
Abstract
Next-generation sequencing has enhanced discovery of many disease-associated genes in previously unexplained epilepsies, mainly in developmental and epileptic encephalopathies and familial epilepsies. We now classify these disorders according to the underlying molecular pathways, which encompass a diverse array of cellular and sub-cellular compartments/signalling processes including voltage-gated ion-channel defects. With the aim to develop and increase the use of precision medicine therapies, understanding the pathogenic mechanisms and consequences of disease-causing variants has gained major relevance in clinical care. The super-family of voltage-gated potassium channels is the largest and most diverse family among the ion channels, encompassing approximately 80 genes. Key potassium channelopathies include those affecting the KV, KCa and Kir families, a significant proportion of which have been implicated in neurological disease. As for other ion channel disorders, different pathogenic variants within any individual voltage-gated potassium channel gene tend to affect channel protein function differently, causing heterogeneous clinical phenotypes. The focus of this review is to summarise recent clinical developments regarding the key voltage-gated potassium (KV) family-related epilepsies, which now encompasses approximately 12 established disease-associated genes, from the KCNA-, KCNB-, KCNC-, KCND-, KCNV-, KCNQ- and KCNH-subfamilies.
Collapse
Affiliation(s)
- Nicholas M Allen
- Department of Paediatrics, National University of Ireland, Galway, Ireland; Department of Paediatrics (Neurology), Galway University Hospital, Ireland; Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
| | - Sarah Weckhuysen
- Neurogenetics Group, Center for Molecular Neurology, VIB-University of Antwerp, Antwerp, Belgium; Department of Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Kathleen Gorman
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tubingen, Germany
| |
Collapse
|
24
|
Bar C, Barcia G, Jennesson M, Le Guyader G, Schneider A, Mignot C, Lesca G, Breuillard D, Montomoli M, Keren B, Doummar D, Billette de Villemeur T, Afenjar A, Marey I, Gerard M, Isnard H, Poisson A, Dupont S, Berquin P, Meyer P, Genevieve D, De Saint Martin A, El Chehadeh S, Chelly J, Guët A, Scalais E, Dorison N, Myers CT, Mefford HC, Howell KB, Marini C, Freeman JL, Nica A, Terrone G, Sekhara T, Lebre A, Odent S, Sadleir LG, Munnich A, Guerrini R, Scheffer IE, Kabashi E, Nabbout R. Expanding the genetic and phenotypic relevance of
KCNB1
variants in developmental and epileptic encephalopathies: 27 new patients and overview of the literature. Hum Mutat 2019; 41:69-80. [DOI: 10.1002/humu.23915] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/28/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Claire Bar
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
| | - Giulia Barcia
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
- Department of genetics, Necker Enfants Malades hospitalAssistance Publique‐Hôpitaux de ParisParis France
| | | | - Gwenaël Le Guyader
- Department of geneticsUniversity hospital PoitiersPoitiers Cedex France
- EA3808‐NEUVACOD Unité Neurovasculaire et Troubles Cognitifs, Pôle Biologie SantéUniversité de PoitiersPoitiers France
| | - Amy Schneider
- Department of Medicine, Epilepsy Research Centre, Austin HealthThe University of MelbourneHeidelberg Victoria Australia
| | - Cyril Mignot
- Institut du Cerveau et de la Moelle épinière, INSERM, U 1127, CNRS UMR 7225Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Paris France
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | - Gaetan Lesca
- Department of geneticsHospices Civils de LyonLyon France
- Neurosciences centre of Lyon, INSERM U1028, UMR CNRS 5292Université Claude Bernard Lyon 1Bron Cedex France
| | - Delphine Breuillard
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
| | - Martino Montomoli
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Boris Keren
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | - Diane Doummar
- Department of Pediatric Neurology, Hôpital Armand TrousseauAP‐HPParis France
| | | | - Alexandra Afenjar
- Département de Génétique et Embryologie Médicale, Pathologies Congénitales du Cervelet‐LeucoDystrophies, Centre de Référence déficiences intellectuelles de causes rares, AP‐HP, Hôpital Armand Trousseau, GRC n°19Sorbonne UniversitéParis France
| | - Isabelle Marey
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | | | | | - Alice Poisson
- Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR‐Psy TeamCentre National de la Recherche Scientifique & Lyon 1 Claude Bernard UniversityVilleurbanne France
| | - Sophie Dupont
- Institut du Cerveau et de la Moelle épinière, INSERM, U 1127, CNRS UMR 7225Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Paris France
- Epileptology and Rehabilitation department, GH Pitie‐Salpêtrière‐Charles FoixAP‐HPParis France
| | - Patrick Berquin
- Department of pediatric neurology Amiens‐Picardie university hospitalUniversité de Picardie Jules VerneAmiens France
| | - Pierre Meyer
- Department of pediatric neurologyMontpellier university hospitalMontpellier France
- PhyMedExp, U1046 INSERMUMR9214 CNRSMontpellier France
| | - David Genevieve
- Service de génétique clinique et du Département de Génétique Médicale, Maladies Rares et Médecine Personnalisée, Centre de référence maladies rares anomalies du développementCHU MontpellierMontpellier France
| | - Anne De Saint Martin
- Department of Pediatric NeurologyStrasbourg University HospitalStrasbourg France
| | - Salima El Chehadeh
- Department of genetics, Hôpital de HautepierreHôpitaux Universitaires de StrasbourgStrasbourg France
| | - Jamel Chelly
- Department of genetics, Hôpital de HautepierreHôpitaux Universitaires de StrasbourgStrasbourg France
| | - Agnès Guët
- Department of PediatricLouis‐Mourier HospitalColombes France
| | - Emmanuel Scalais
- Department of Pediatric Neurology, Centre Hospitalier de LuxembourgLuxembourg CityLuxembourg City Luxembourg
| | - Nathalie Dorison
- Department of pediatric NeurosurgeryRothschild Foundation HospitalParis France
| | - Candace T. Myers
- Department of PediatricsUniversity of WashingtonSeattle Washington
| | - Heather C. Mefford
- Department of Pediatrics, Division of Genetic MedicineUniversity of WashingtonSeattle Washington
| | - Katherine B. Howell
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- Murdoch Children's Research InstituteMelbourne Victoria Australia
| | - Carla Marini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Jeremy L. Freeman
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- Murdoch Children's Research InstituteMelbourne Victoria Australia
| | - Anca Nica
- Department of Neurology, Center for Clinical Research (CIC 1414)Rennes University HospitalRennes France
| | - Gaetano Terrone
- Department of Translational Medical Sciences, Section of Pediatrics‐Child Neurology UnitFederico II UniversityNaples Italy
| | - Tayeb Sekhara
- Department of Pediatric NeurologyC.H.I.R.E.CBrussels Belgium
| | - Anne‐Sophie Lebre
- Department of genetics, Maison Blanche hospitalUniversity hospital, ReimsReims France
| | - Sylvie Odent
- Reference Centre for Rare Developmental AbnormalitiesCLAD‐Ouest, CHU RennesRennes France
- Institute of genetics and developmentCNRS UMR 6290, Rennes universityRennes France
| | - Lynette G. Sadleir
- Department of Paediatrics and Child HealthUniversity of OtagoWellington New Zealand
| | - Arnold Munnich
- Université Paris Descartes‐Sorbonne Paris CitéParis France
- Department of genetics, Necker Enfants Malades hospitalAssistance Publique‐Hôpitaux de ParisParis France
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Ingrid E. Scheffer
- Department of Medicine, Epilepsy Research Centre, Austin HealthThe University of MelbourneHeidelberg Victoria Australia
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- The Florey Institute of Neurosciences and Mental HealthHeidelberg Victoria Australia
| | - Edor Kabashi
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
| | - Rima Nabbout
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
| |
Collapse
|
25
|
Hsiao CT, Fu SJ, Liu YT, Lu YH, Zhong CY, Tang CY, Soong BW, Jeng CJ. Novel SCA19/22-associated KCND3 mutations disrupt human K V 4.3 protein biosynthesis and channel gating. Hum Mutat 2019; 40:2088-2107. [PMID: 31293010 DOI: 10.1002/humu.23865] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/05/2019] [Accepted: 07/07/2019] [Indexed: 11/07/2022]
Abstract
Mutations in the human voltage-gated K+ channel subunit KV 4.3-encoding KCND3 gene have been associated with the autosomal dominant neurodegenerative disorder spinocerebellar ataxia types 19 and 22 (SCA19/22). The precise pathophysiology underlying the dominant inheritance pattern of SCA19/22 remains elusive. Using cerebellar ataxia-specific targeted next-generation sequencing technology, we identified two novel KCND3 mutations, c.950 G>A (p.C317Y) and c.1123 C>T (p.P375S) from a cohort with inherited cerebellar ataxias in Taiwan. The patients manifested notable phenotypic heterogeneity that includes cognitive impairment. We employed in vitro heterologous expression systems to inspect the biophysical and biochemical properties of human KV 4.3 harboring the two novel mutations, as well as two previously reported but uncharacterized disease-related mutations, c.1013 T>A (p.V338E) and c.1130 C>T (p.T377M). Electrophysiological analyses revealed that all of these SCA19/22-associated KV 4.3 mutant channels manifested loss-of-function phenotypes. Protein chemistry and immunofluorescence analyses further demonstrated that these mutants displayed enhanced protein degradation and defective membrane trafficking. By coexpressing KV 4.3 wild-type with the disease-related mutants, we provided direct evidence showing that the mutants instigated anomalous protein biosynthesis and channel gating of KV 4.3. We propose that the dominant inheritance pattern of SCA19/22 may be explained by the dominant-negative effects of the mutants on protein biosynthesis and voltage-dependent gating of KV 4.3 wild-type channel.
Collapse
Affiliation(s)
- Cheng-Tsung Hsiao
- Department of Internal Medicine, Taipei Veterans General Hospital Taoyuan Branch, Taoyuan, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
- Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ssu-Ju Fu
- Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yo-Tsen Liu
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Hsiang Lu
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ciao-Yu Zhong
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Yung Tang
- Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Bing-Wen Soong
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
- Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan
| | - Chung-Jiuan Jeng
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
26
|
Novel De Novo KCND3 Mutation in a Japanese Patient with Intellectual Disability, Cerebellar Ataxia, Myoclonus, and Dystonia. THE CEREBELLUM 2019; 17:237-242. [PMID: 28895081 DOI: 10.1007/s12311-017-0883-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Spinocerebellar ataxia 19/22 (SCA19/22) is a rare type of autosomal dominant SCA that was previously described in 11 families. We report the case of a 30-year-old Japanese man presenting with intellectual disability, early onset cerebellar ataxia, myoclonus, and dystonia without a family history. MRI showed cerebellar atrophy, and electroencephalograms showed paroxysmal sharp waves during hyperventilation and photic stimulation. Trio whole-exome sequencing analysis of DNA samples from the patient and his parents revealed a de novo novel missense mutation (c.1150G>A, p.G384S) in KCND3, the causative gene of SCA19/22, substituting for evolutionally conserved glycine. The mutation was predicted to be functionally deleterious by bioinformatic analysis. Although pure cerebellar ataxia is the most common clinical feature in SCA19/22 families, extracerebellar symptoms including intellectual disability and myoclonus are reported in a limited number of families, suggesting a genotype-phenotype correlation for particular mutations. Although autosomal recessive diseases are more common in patients with early onset sporadic cerebellar ataxia, the present study emphasizes that such a possibility of de novo mutation should be considered.
Collapse
|
27
|
Abstract
Spinocerebellar ataxia type 19 (SCA19), allelic with spinocerebellar ataxia type 22 (SCA22), is a rare syndrome caused by mutations in the KCND3 gene which encodes the potassium channel Kv4.3. Only 18 SCA19/22 families and sporadic cases of different ethnic backgrounds have been previously reported. As in other SCAs, the SCA19/22 phenotype is variable and usually consists of adult-onset slowly progressive ataxia and cognitive impairment; myoclonus and seizures; mild Parkinsonism occurs in some cases. Here we describe a Swedish SCA19/22 family spanning five generations and harboring the T377M mutation in KCND3. For the first time for this disease, 18F-fluorodeoxyglucose PET was assessed revealing widespread brain hypometabolism. In addition, we identified white matter abnormalities and found unusual features for SCA19/22 including early age of onset and fast rate of progression in the late course of disease in the oldest patient of this family.
Collapse
|
28
|
Peraza DA, Cercós P, Miaja P, Merinero YG, Lagartera L, Socuéllamos PG, Izquierdo García C, Sánchez SA, López-Hurtado A, Martín-Martínez M, Olivos-Oré LA, Naranjo JR, Artalejo AR, Gutiérrez-Rodríguez M, Valenzuela C. Identification of IQM-266, a Novel DREAM Ligand That Modulates K V4 Currents. Front Mol Neurosci 2019; 12:11. [PMID: 30787866 PMCID: PMC6373780 DOI: 10.3389/fnmol.2019.00011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/14/2019] [Indexed: 01/30/2023] Open
Abstract
Downstream Regulatory Element Antagonist Modulator (DREAM)/KChIP3/calsenilin is a neuronal calcium sensor (NCS) with multiple functions, including the regulation of A-type outward potassium currents (I A). This effect is mediated by the interaction between DREAM and KV4 potassium channels and it has been shown that small molecules that bind to DREAM modify channel function. A-type outward potassium current (I A) is responsible of the fast repolarization of neuron action potentials and frequency of firing. Using surface plasmon resonance (SPR) assays and electrophysiological recordings of KV4.3/DREAM channels, we have identified IQM-266 as a DREAM ligand. IQM-266 inhibited the KV4.3/DREAM current in a concentration-, voltage-, and time-dependent-manner. By decreasing the peak current and slowing the inactivation kinetics, IQM-266 led to an increase in the transmembrane charge ( Q K V 4.3 / DREAM ) at a certain range of concentrations. The slowing of the recovery process and the increase of the inactivation from the closed-state inactivation degree are consistent with a preferential binding of IQM-266 to a pre-activated closed state of KV4.3/DREAM channels. Finally, in rat dorsal root ganglion neurons, IQM-266 inhibited the peak amplitude and slowed the inactivation of I A. Overall, the results presented here identify IQM-266 as a new chemical tool that might allow a better understanding of DREAM physiological role as well as modulation of neuronal I A in pathological processes.
Collapse
Affiliation(s)
- Diego A Peraza
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Pilar Cercós
- Instituto de Química Médica (IQM), IQM-CSIC, Madrid, Spain
| | - Pablo Miaja
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain
| | - Yaiza G Merinero
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain
| | | | - Paula G Socuéllamos
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica & Departamento de Farmacología y Toxicología, Facultad de Veterinaria, UCM, Madrid, Spain
| | | | - Sara A Sánchez
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain
| | - Alejandro López-Hurtado
- Centro Nacional de Biotecnología (CNB), CNB-CSIC, Madrid, Spain.,Spanish Network for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Luis A Olivos-Oré
- Instituto Universitario de Investigación en Neuroquímica & Departamento de Farmacología y Toxicología, Facultad de Veterinaria, UCM, Madrid, Spain
| | - José R Naranjo
- Centro Nacional de Biotecnología (CNB), CNB-CSIC, Madrid, Spain.,Spanish Network for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio R Artalejo
- Instituto Universitario de Investigación en Neuroquímica & Departamento de Farmacología y Toxicología, Facultad de Veterinaria, UCM, Madrid, Spain
| | | | - Carmen Valenzuela
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBM), CSIC-UAM, Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
29
|
Wang J, Wen Y, Zhang Q, Yu S, Chen Y, Wu X, Zhang Y, Bao X. Gene mutational analysis in a cohort of Chinese children with unexplained epilepsy: Identification of a new KCND3 phenotype and novel genes causing Dravet syndrome. Seizure 2019; 66:26-30. [PMID: 30776697 DOI: 10.1016/j.seizure.2019.01.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 01/24/2019] [Accepted: 01/26/2019] [Indexed: 01/10/2023] Open
Abstract
PURPOSE This study aimed to investigate the genetic etiology of epilepsy in a cohort of Chinese children. METHODS Targeted next-generation sequencing (NGS) was performed for 120 patients with unexplained epilepsy, including 71 patients with early-onset epileptic encephalopathies, and 16 patients with Dravet syndrome (including three patients with a Dravet-like phenotype) but without SCN1A pathogenic variants. RESULTS Pathogenic variants of 14 genes were discovered in 22 patients (18%). A de novo KCND3 pathogenic variant (c.1174G > A, p.Val392Ile) was identified in a boy with refractory epilepsy, psychomotor regression, attention deficit, and visual decline. Pathogenic variants in other coding genes were excluded via whole exome sequencing. This KCND3 variant was previously confirmed to be pathogenic by Giudicessi, et al. However, the clinical profile was different: sudden death at 20 years old without any medical history of neurological disorders, nor with any diseases typically caused by KCND3 pathogenic variants such as Brugada syndrome, spinocerebellar ataxia type 19/22 or ataxia accompanied by epilepsy. This indicates that we have identified a new KCND3 phenotype. In addition, we also uncovered a GRIN1 pathogenic variant and a novel HCN1 pathogenic variant in the Dravet cohort. CONCLUSION Our study highlights the significant utility of NGS panels in the genetic diagnosis of pediatric epilepsy. Our findings indicate that KCND3 pathogenic variants may be responsible for a wider phenotypic spectrum than previously thought, by including childhood epileptic encephalopathy. Furthermore, this study provides evidence that GRIN1 and HCN1 are candidate genes for Dravet and Dravet-like phenotypes.
Collapse
Affiliation(s)
- Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Shujie Yu
- Department of Neurology, Harbin Children's Hospital, Harbin 150010, Heilongjiang Province, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - YueHua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
| |
Collapse
|
30
|
Calloe K. Doctoral Dissertation: The transient outward potassium current in healthy and diseased hearts. Acta Physiol (Oxf) 2019; 225 Suppl 717:e13225. [PMID: 30628199 DOI: 10.1111/apha.13225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Kirstine Calloe
- Section for Anatomy; Biochemistry and Physiology; Department for Veterinary and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Frederiksberg C Denmark
| |
Collapse
|
31
|
Synofzik M, Helbig KL, Harmuth F, Deconinck T, Tanpaiboon P, Sun B, Guo W, Wang R, Palmaer E, Tang S, Schaefer GB, Gburek-Augustat J, Züchner S, Krägeloh-Mann I, Baets J, de Jonghe P, Bauer P, Chen SRW, Schöls L, Schüle R. De novo ITPR1 variants are a recurrent cause of early-onset ataxia, acting via loss of channel function. Eur J Hum Genet 2018; 26:1623-1634. [PMID: 29925855 PMCID: PMC6189112 DOI: 10.1038/s41431-018-0206-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 03/26/2018] [Accepted: 06/05/2018] [Indexed: 12/26/2022] Open
Abstract
We explored the clinico-genetic basis of spinocerebellar ataxia 29 (SCA29) by determining the frequency, phenotype, and functional impact of ITPR1 missense variants associated with early-onset ataxia (EOA). Three hundred thirty one patients from a European EOA target cohort (n = 120), US-American EOA validation cohort (n = 72), and early-onset epileptic encephalopathy (EOEE) control cohort (n = 139) were screened for de novo ITPR1 variants. The target cohort was also screened for inherited ITPR1 variants. The variants' functional impact was determined by IP3-induced Ca2+ release in HEK293 cells. 3/120 patients (2.5%) from the target cohort and 4/72 patients (5.5%) from the validation cohort, but none from the EOEE control cohort, carried de novo ITPR1 variants. However, most ITPR1 variants (7/10 = 70%) in the target cohort were inherited from a healthy parent, with 3/6 patients carrying disease-causing variants in other genes. This suggests limited or no phenotypic impact of many ITPR1 missense variants, even if ultra-rare and well-conserved. While common bioinformatics tools did not discriminate de novo from other ITPR1 variants, functional characterization demonstrated reduced IP3-induced Ca2+ release for all de novo variants, including the recurrent c.805C>T (p.(R269W)) variant. In sum, these findings show that de novo ITPR1 missense variants are a recurrent cause of EOA (SCA29) across independent cohorts, acting via loss of IP3 channel function. Inherited ITPR1 variants are also enriched in EOA, but often without strong impact, albeit rare and well-conserved. Functional studies allow identifying ITPR1 variants with large impact, likely disease-causing. Such functional confirmation is warranted for inherited ITPR1 variants before making a SCA29 diagnosis.
Collapse
Affiliation(s)
- Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
- German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany.
| | | | - Florian Harmuth
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tine Deconinck
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
| | - Pranoot Tanpaiboon
- Division of Genetics and Metabolism, Children's National Health System, Washington, USA
| | - Bo Sun
- Libin Cardiovascular Institute of Alberta, Departments of Physiology & Pharmacology, and Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Departments of Physiology & Pharmacology, and Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Departments of Physiology & Pharmacology, and Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Erika Palmaer
- Division of Clinical Genomics, Ambry Genetics, Aliso Viejo, CA, USA
| | - Sha Tang
- Division of Clinical Genomics, Ambry Genetics, Aliso Viejo, CA, USA
| | - G Bradley Schaefer
- Division of Medical Genetics, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Janina Gburek-Augustat
- Department of Neuropediatrics, Children's University Hospital, Tübingen, Germany
- Department of Paediatric Neurology and Metabolic Disorders, Centre for Paediatrics and Adolescent Medicine, Hannover Medical School, Hannover, Germany
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, USA
| | | | - Jonathan Baets
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
- Department of Neurology, Antwerp University Hospital, Edegem, Belgium
- Laboratories of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter de Jonghe
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
- Department of Neurology, Antwerp University Hospital, Edegem, Belgium
- Laboratories of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
- Centogene AG, Rostock, Germany
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Departments of Physiology & Pharmacology, and Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Rebecca Schüle
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| |
Collapse
|
32
|
Johnson SA, Spollen WG, Manshack LK, Bivens NJ, Givan SA, Rosenfeld CS. Hypothalamic transcriptomic alterations in male and female California mice ( Peromyscus californicus) developmentally exposed to bisphenol A or ethinyl estradiol. Physiol Rep 2018; 5:5/3/e13133. [PMID: 28196854 PMCID: PMC5309579 DOI: 10.14814/phy2.13133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/15/2016] [Accepted: 12/26/2016] [Indexed: 12/22/2022] Open
Abstract
Bisphenol A (BPA) is an endocrine‐disrupting chemical (EDC) prevalent in many household items. Rodent models and human epidemiological studies have linked this chemical to neurobehavior impairments. In California mice, developmental exposure to BPA results in sociosexual disorders at adulthood, including communication and biparental care deficits, behaviors that are primarily regulated by the hypothalamus. Thus, we sought to examine the transcriptomic profile in this brain region of juvenile male and female California mice offspring exposed from periconception through lactation to BPA or ethinyl estradiol (EE, estrogen present in birth control pills and considered a positive estrogen control for BPA studies). Two weeks prior to breeding, P0 females were fed a control diet, or this diet supplemented with 50 mg BPA/kg feed weight or 0.1 ppb EE, and continued on the diets through lactation. At weaning, brains from male and female offspring were collected, hypothalamic RNA isolated, and RNA‐seq analysis performed. Results indicate that BPA and EE groups clustered separately from controls with BPA and EE exposure leading to unique set of signature gene profiles. Kcnd3 was downregulated in the hypothalamus of BPA‐ and EE‐exposed females, whereas Tbl2, Topors, Kif3a, and Phactr2 were upregulated in these groups. Comparison of transcripts differentially expressed in BPA and EE groups revealed significant enrichment of gene ontology terms associated with microtubule‐based processes. Current results show that perinatal exposure to BPA or EE can result in several transcriptomic alterations, including those associated with microtubule functions, in the hypothalamus of California mice. It remains to be determined whether these genes mediate BPA‐induced behavioral disruptions.
Collapse
Affiliation(s)
- Sarah A Johnson
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Biomedical Sciences, University of Missouri, Columbia, Missouri.,Animal Sciences, University of Missouri, Columbia, Missouri
| | - William G Spollen
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Informatics Research Core Facility University of Missouri, Columbia, Missouri
| | - Lindsey K Manshack
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Nathan J Bivens
- DNA Core Facility, University of Missouri, Columbia, Missouri
| | - Scott A Givan
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri .,Informatics Research Core Facility University of Missouri, Columbia, Missouri.,Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri
| | - Cheryl S Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri .,Biomedical Sciences, University of Missouri, Columbia, Missouri.,Genetics Area Program, University of Missouri, Columbia, Missouri.,Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, Missouri
| |
Collapse
|
33
|
Hoxha E, Balbo I, Miniaci MC, Tempia F. Purkinje Cell Signaling Deficits in Animal Models of Ataxia. Front Synaptic Neurosci 2018; 10:6. [PMID: 29760657 PMCID: PMC5937225 DOI: 10.3389/fnsyn.2018.00006] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/09/2018] [Indexed: 12/19/2022] Open
Abstract
Purkinje cell (PC) dysfunction or degeneration is the most frequent finding in animal models with ataxic symptoms. Mutations affecting intrinsic membrane properties can lead to ataxia by altering the firing rate of PCs or their firing pattern. However, the relationship between specific firing alterations and motor symptoms is not yet clear, and in some cases PC dysfunction precedes the onset of ataxic signs. Moreover, a great variety of ionic and synaptic mechanisms can affect PC signaling, resulting in different features of motor dysfunction. Mutations affecting Na+ channels (NaV1.1, NaV1.6, NaVβ4, Fgf14 or Rer1) reduce the firing rate of PCs, mainly via an impairment of the Na+ resurgent current. Mutations that reduce Kv3 currents limit the firing rate frequency range. Mutations of Kv1 channels act mainly on inhibitory interneurons, generating excessive GABAergic signaling onto PCs, resulting in episodic ataxia. Kv4.3 mutations are responsible for a complex syndrome with several neurologic dysfunctions including ataxia. Mutations of either Cav or BK channels have similar consequences, consisting in a disruption of the firing pattern of PCs, with loss of precision, leading to ataxia. Another category of pathogenic mechanisms of ataxia regards alterations of synaptic signals arriving at the PC. At the parallel fiber (PF)-PC synapse, mutations of glutamate delta-2 (GluD2) or its ligand Crbl1 are responsible for the loss of synaptic contacts, abolishment of long-term depression (LTD) and motor deficits. At the same synapse, a correct function of metabotropic glutamate receptor 1 (mGlu1) receptors is necessary to avoid ataxia. Failure of climbing fiber (CF) maturation and establishment of PC mono-innervation occurs in a great number of mutant mice, including mGlu1 and its transduction pathway, GluD2, semaphorins and their receptors. All these models have in common the alteration of PC output signals, due to a variety of mechanisms affecting incoming synaptic signals or the way they are processed by the repertoire of ionic channels responsible for intrinsic membrane properties. Although the PC is a final common pathway of ataxia, the link between specific firing alterations and neurologic symptoms has not yet been systematically studied and the alterations of the cerebellar contribution to motor signals are still unknown.
Collapse
Affiliation(s)
- Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy
| | - Ilaria Balbo
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy
| | - Maria Concetta Miniaci
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy.,National Institute of Neuroscience (INN), Turin, Italy
| |
Collapse
|
34
|
Carpenter JC, Schorge S. The voltage-gated channelopathies as a paradigm for studying epilepsy-causing genes. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
35
|
Bushart DD, Shakkottai VG. Ion channel dysfunction in cerebellar ataxia. Neurosci Lett 2018; 688:41-48. [PMID: 29421541 DOI: 10.1016/j.neulet.2018.02.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/02/2018] [Indexed: 12/31/2022]
Abstract
Cerebellar ataxias constitute a heterogeneous group of disorders that result in impaired speech, uncoordinated limb movements, and impaired balance, often ultimately resulting in wheelchair confinement. Motor dysfunction in ataxia can be attributed to dysfunction and degeneration of neurons in the cerebellum and its associated pathways. Recent work has suggested the importance of cerebellar neuronal dysfunction resulting from mutations in specific ion-channels that regulate membrane excitability in the pathogenesis of cerebellar ataxia in humans. Importantly, even in ataxias not directly due to ion-channel mutations, transcriptional changes resulting in ion-channel dysfunction are tied to motor dysfunction and degeneration in models of disease. In this review, we describe the role that ion-channel dysfunction plays in a variety of cerebellar ataxias, and postulate that a potential therapeutic strategy that targets specific ion-channels exists for cerebellar ataxia.
Collapse
Affiliation(s)
- David D Bushart
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor MI, USA
| | - Vikram G Shakkottai
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor MI, USA; Department of Neurology, University of Michigan, 4009 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
36
|
|
37
|
Symonds JD, Zuberi SM. Genetics update: Monogenetics, polygene disorders and the quest for modifying genes. Neuropharmacology 2017; 132:3-19. [PMID: 29037745 DOI: 10.1016/j.neuropharm.2017.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/19/2022]
Abstract
The genetic channelopathies are a broad collection of diseases. Many ion channel genes demonstrate wide phenotypic pleiotropy, but nonetheless concerted efforts have been made to characterise genotype-phenotype relationships. In this review we give an overview of the factors that influence genotype-phenotype relationships across this group of diseases as a whole, using specific individual channelopathies as examples. We suggest reasons for the limitations observed in these relationships. We discuss the role of ion channel variation in polygenic disease and highlight research that has contributed to unravelling the complex aetiological nature of these conditions. We focus specifically on the quest for modifying genes in inherited channelopathies, using the voltage-gated sodium channels as an example. Epilepsy related to genetic channelopathy is one area in which precision medicine is showing promise. We will discuss the successes and limitations of precision medicine in these conditions. This article is part of the Special Issue entitled 'Channelopathies.'
Collapse
Affiliation(s)
- Joseph D Symonds
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
| | - Sameer M Zuberi
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK.
| |
Collapse
|
38
|
Jiménez-Vargas JM, Possani LD, Luna-Ramírez K. Arthropod toxins acting on neuronal potassium channels. Neuropharmacology 2017; 127:139-160. [PMID: 28941737 DOI: 10.1016/j.neuropharm.2017.09.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Abstract
Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels. A brief description of the K+ channels classification and structure is included and a compendium of neuronal K+ channels and the arthropod toxins that modify them have been listed. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
Collapse
Affiliation(s)
- Juana María Jiménez-Vargas
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Karen Luna-Ramírez
- Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| |
Collapse
|
39
|
Huin V, Strubi-Vuillaume I, Dujardin K, Brion M, Delliaux M, Dellacherie D, Cuvellier JC, Cuisset JM, Riquet A, Moreau C, Defebvre L, Sablonnière B, Devos D. Expanding the phenotype of SCA19/22: Parkinsonism, cognitive impairment and epilepsy. Parkinsonism Relat Disord 2017; 45:85-89. [PMID: 28947073 DOI: 10.1016/j.parkreldis.2017.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/01/2017] [Accepted: 09/13/2017] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Spinocerebellar ataxia types 19 and 22 (SCA19/22) are rare conditions in which relatively isolated cerebellar involvement is frequently associated with cognitive impairment. Here, we report on new clinical features and provide details of the cognitive profile in two SCA19/22 families. METHODS Two families displaying an autosomal-dominant form of cerebellar ataxia underwent clinical examinations and genetic testing. RESULTS In addition to the classical clinical features of SCA, a wide spectrum of cognitive disorders (including visuospatial impairments) was observed. Eight patients had mild Parkinsonism, and five had epilepsy. Genetic testing showed that the KCND3 mutation (c.679_681delTTC, p.F227del) was present in both families. CONCLUSIONS Our findings broaden the phenotypic spectrum of SCA19/22, and suggest that KCND3 should be included in the list of candidate genes for epilepsy, Parkinsonism and cognitive impairment.
Collapse
Affiliation(s)
- Vincent Huin
- Univ. Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000, Lille, France; CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, F-59000, Lille, France.
| | - Isabelle Strubi-Vuillaume
- CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, F-59000, Lille, France
| | - Kathy Dujardin
- Univ. Lille, Inserm, CHU Lille, U1171 - Degenerative & vascular cognitive disorders, F-59000, Lille, France; CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France
| | - Marine Brion
- CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France
| | - Marie Delliaux
- CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France
| | - Delphine Dellacherie
- CHU Lille, Service de Neuropédiatrie, Hôpital Roger Salengro, F-59000, Lille, France
| | | | - Jean-Marie Cuisset
- CHU Lille, Service de Neuropédiatrie, Hôpital Roger Salengro, F-59000, Lille, France
| | - Audrey Riquet
- CHU Lille, Service de Neuropédiatrie, Hôpital Roger Salengro, F-59000, Lille, France
| | - Caroline Moreau
- Univ. Lille, Inserm, CHU Lille, U1171 - Degenerative & vascular cognitive disorders, F-59000, Lille, France; CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France
| | - Luc Defebvre
- Univ. Lille, Inserm, CHU Lille, U1171 - Degenerative & vascular cognitive disorders, F-59000, Lille, France; CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France
| | - Bernard Sablonnière
- Univ. Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000, Lille, France; CHU Lille, Institut de Biochimie et Biologie moléculaire, Centre de Biologie Pathologie et Génétique, F-59000, Lille, France
| | - David Devos
- Univ. Lille, Inserm, CHU Lille, U1171 - Degenerative & vascular cognitive disorders, F-59000, Lille, France; CHU Lille, Service de Neurologie et Pathologies du Mouvement, Hôpital Roger Salengro, F-59000, Lille, France; CHU Lille, Service de Pharmacologie médicale, Faculté de Médecine, F-59045, Lille, France
| |
Collapse
|
40
|
Venom-derived peptide inhibitors of voltage-gated potassium channels. Neuropharmacology 2017; 127:124-138. [PMID: 28689025 DOI: 10.1016/j.neuropharm.2017.07.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/02/2017] [Accepted: 07/04/2017] [Indexed: 12/11/2022]
Abstract
Voltage-gated potassium channels play a key role in human physiology and pathology. Reflecting their importance, numerous channelopathies have been characterised that arise from mutations in these channels or from autoimmune attack on the channels. Voltage-gated potassium channels are also the target of a broad range of peptide toxins from venomous organisms, including sea anemones, scorpions, spiders, snakes and cone snails; many of these peptides bind to the channels with high potency and selectivity. In this review we describe the various classes of peptide toxins that block these channels and illustrate the broad range of three-dimensional structures that support channel blockade. The therapeutic opportunities afforded by these peptides are also highlighted. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
Collapse
|
41
|
Ion Channel Genes and Epilepsy: Functional Alteration, Pathogenic Potential, and Mechanism of Epilepsy. Neurosci Bull 2017; 33:455-477. [PMID: 28488083 DOI: 10.1007/s12264-017-0134-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/20/2017] [Indexed: 01/29/2023] Open
Abstract
Ion channels are crucial in the generation and modulation of excitability in the nervous system and have been implicated in human epilepsy. Forty-one epilepsy-associated ion channel genes and their mutations are systematically reviewed. In this paper, we analyzed the genotypes, functional alterations (funotypes), and phenotypes of these mutations. Eleven genes featured loss-of-function mutations and six had gain-of-function mutations. Nine genes displayed diversified funotypes, among which a distinct funotype-phenotype correlation was found in SCN1A. These data suggest that the funotype is an essential consideration in evaluating the pathogenicity of mutations and a distinct funotype or funotype-phenotype correlation helps to define the pathogenic potential of a gene.
Collapse
|
42
|
Identification of six new genetic loci associated with atrial fibrillation in the Japanese population. Nat Genet 2017; 49:953-958. [DOI: 10.1038/ng.3842] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/20/2017] [Indexed: 11/08/2022]
|
43
|
Rinker JA, Fulmer DB, Trantham-Davidson H, Smith ML, Williams RW, Lopez MF, Randall PK, Chandler LJ, Miles MF, Becker HC, Mulholland PJ. Differential potassium channel gene regulation in BXD mice reveals novel targets for pharmacogenetic therapies to reduce heavy alcohol drinking. Alcohol 2017; 58:33-45. [PMID: 27432260 DOI: 10.1016/j.alcohol.2016.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/12/2016] [Accepted: 05/03/2016] [Indexed: 12/22/2022]
Abstract
Alcohol (ethanol) dependence is a chronic relapsing brain disorder partially influenced by genetics and characterized by an inability to regulate harmful levels of drinking. Emerging evidence has linked genes that encode KV7, KIR, and KCa2 K+ channels with variation in alcohol-related behaviors in rodents and humans. This led us to experimentally test relations between K+ channel genes and escalation of drinking in a chronic-intermittent ethanol (CIE) exposure model of dependence in BXD recombinant inbred strains of mice. Transcript levels for K+ channel genes in the prefrontal cortex (PFC) and nucleus accumbens (NAc) covary with voluntary ethanol drinking in a non-dependent cohort. Transcripts that encode KV7 channels covary negatively with drinking in non-dependent BXD strains. Using a pharmacological approach to validate the genetic findings, C57BL/6J mice were allowed intermittent access to ethanol to establish baseline consumption before they were treated with retigabine, an FDA-approved KV7 channel positive modulator. Systemic administration significantly reduced drinking, and consistent with previous evidence, retigabine was more effective at reducing voluntary consumption in high-drinking than low-drinking subjects. We evaluated the specific K+ channel genes that were most sensitive to CIE exposure and identified a gene subset in the NAc and PFC that were dysregulated in the alcohol-dependent BXD cohort. CIE-induced modulation of nine genes in the NAc and six genes in the PFC covaried well with the changes in drinking induced by ethanol dependence. Here we identified novel candidate genes in the NAc and PFC that are regulated by ethanol dependence and correlate with voluntary drinking in non-dependent and dependent BXD mice. The findings that Kcnq expression correlates with drinking and that retigabine reduces consumption suggest that KV7 channels could be pharmacogenetic targets to treat individuals with alcohol addiction.
Collapse
|
44
|
Jiang X, Lachance M, Rossignol E. Involvement of cortical fast-spiking parvalbumin-positive basket cells in epilepsy. PROGRESS IN BRAIN RESEARCH 2016; 226:81-126. [PMID: 27323940 DOI: 10.1016/bs.pbr.2016.04.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GABAergic interneurons of the parvalbumin-positive fast-spiking basket cells subtype (PV INs) are important regulators of cortical network excitability and of gamma oscillations, involved in signal processing and cognition. Impaired development or function of PV INs has been associated with epilepsy in various animal models of epilepsy, as well as in some genetic forms of epilepsy in humans. In this review, we provide an overview of some of the experimental data linking PV INs dysfunction with epilepsy, focusing on disorders of the specification, migration, maturation, synaptic function, or connectivity of PV INs. Furthermore, we reflect on the potential therapeutic use of cell-type specific stimulation of PV INs within active networks and on the transplantation of PV INs precursors in the treatment of epilepsy and its comorbidities.
Collapse
Affiliation(s)
- X Jiang
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - M Lachance
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - E Rossignol
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada.
| |
Collapse
|
45
|
Villa C, Combi R. Potassium Channels and Human Epileptic Phenotypes: An Updated Overview. Front Cell Neurosci 2016; 10:81. [PMID: 27064559 PMCID: PMC4811893 DOI: 10.3389/fncel.2016.00081] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/15/2016] [Indexed: 12/03/2022] Open
Abstract
Potassium (K+) channels are expressed in almost every cells and are ubiquitous in neuronal and glial cell membranes. These channels have been implicated in different disorders, in particular in epilepsy. K+ channel diversity depends on the presence in the human genome of a large number of genes either encoding pore-forming or accessory subunits. More than 80 genes encoding the K+ channels were cloned and they represent the largest group of ion channels regulating the electrical activity of cells in different tissues, including the brain. It is therefore not surprising that mutations in these genes lead to K+ channels dysfunctions linked to inherited epilepsy in humans and non-human model animals. This article reviews genetic and molecular progresses in exploring the pathogenesis of different human epilepsies, with special emphasis on the role of K+ channels in monogenic forms.
Collapse
Affiliation(s)
- Chiara Villa
- School of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Romina Combi
- School of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| |
Collapse
|