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Ramirez-Franco J, Debreux K, Sangiardi M, Belghazi M, Kim Y, Lee SH, Lévêque C, Seagar M, El Far O. The downregulation of Kv 1 channels in Lgi1 -/-mice is accompanied by a profound modification of its interactome and a parallel decrease in Kv 2 channels. Neurobiol Dis 2024; 196:106513. [PMID: 38663634 DOI: 10.1016/j.nbd.2024.106513] [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: 11/08/2023] [Revised: 03/12/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024] Open
Abstract
In animal models of LGI1-dependent autosomal dominant lateral temporal lobe epilepsy, Kv1 channels are downregulated, suggesting their crucial involvement in epileptogenesis. The molecular basis of Kv1 channel-downregulation in LGI1 knock-out mice has not been elucidated and how the absence of this extracellular protein induces an important modification in the expression of Kv1 remains unknown. In this study we analyse by immunofluorescence the modifications in neuronal Kv1.1 and Kv1.2 distribution throughout the hippocampal formation of LGI1 knock-out mice. We show that Kv1 downregulation is not restricted to the axonal compartment, but also takes place in the somatodendritic region and is accompanied by a drastic decrease in Kv2 expression levels. Moreover, we find that the downregulation of these Kv channels is associated with a marked increase in bursting patterns. Finally, mass spectrometry uncovered key modifications in the Kv1 interactome that highlight the epileptogenic implication of Kv1 downregulation in LGI1 knock-out animals.
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Affiliation(s)
- Jorge Ramirez-Franco
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
| | - Kévin Debreux
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Marion Sangiardi
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Maya Belghazi
- Marseille Protéomique (MaP), Plateforme Protéomique IMM, CNRS FR3479, Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13009 Marseille, France
| | - Yujin Kim
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Suk-Ho Lee
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Christian Lévêque
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Michael Seagar
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Oussama El Far
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
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Zhao T, Wang L, Chen F. Potassium channel-related epilepsy: Pathogenesis and clinical features. Epilepsia Open 2024; 9:891-905. [PMID: 38560778 PMCID: PMC11145612 DOI: 10.1002/epi4.12934] [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: 04/25/2023] [Revised: 03/11/2024] [Accepted: 03/17/2024] [Indexed: 04/04/2024] Open
Abstract
Variants in potassium channel-related genes are one of the most important mechanisms underlying abnormal neuronal excitation and disturbances in the cellular resting membrane potential. These variants can cause different forms of epilepsy, which can seriously affect the physical and mental health of patients, especially those with refractory epilepsy or status epilepticus, which are common among pediatric patients and are potentially life-threatening. Variants in potassium ion channel-related genes have been reported in few studies; however, to our knowledge, no systematic review has been published. This study aimed to summarize the epilepsy phenotypes, functional studies, and pharmacological advances associated with different potassium channel gene variants to assist clinical practitioners and drug development teams to develop evidence-based medicine and guide research strategies. PubMed and Google Scholar were searched for relevant literature on potassium channel-related epilepsy reported in the past 5-10 years. Various common potassium ion channel gene variants can lead to heterogeneous epilepsy phenotypes, and functional effects can result from gene deletions and compound effects. Administration of select anti-seizure medications is the primary treatment for this type of epilepsy. Most patients are refractory to anti-seizure medications, and some novel anti-seizure medications have been found to improve seizures. Use of targeted drugs to correct aberrant channel function based on the type of potassium channel gene variant can be used as an evidence-based pathway to achieve precise and individualized treatment for children with epilepsy. PLAIN LANGUAGE SUMMARY: In this article, the pathogenesis and clinical characteristics of epilepsy caused by different types of potassium channel gene variants are reviewed in the light of the latest research literature at home and abroad, with the expectation of providing a certain theoretical basis for the diagnosis and treatment of children with this type of disease.
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Affiliation(s)
- Tong Zhao
- Hebei Children's HospitalShijiazhuangHebeiChina
| | - Le Wang
- Hebei Children's HospitalShijiazhuangHebeiChina
| | - Fang Chen
- Hebei Children's HospitalShijiazhuangHebeiChina
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Sun WB, Fu JX, Chen YL, Li HF, Wu ZY, Chen DF. Both gain- and loss-of-function variants of KCNA1 are associated with paroxysmal kinesigenic dyskinesia. J Genet Genomics 2024:S1673-8527(24)00066-3. [PMID: 38570113 DOI: 10.1016/j.jgg.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/05/2024]
Abstract
KCNA1 is the coding gene for Kv1.1 voltage-gated potassium-channel α subunit. Three variants of KCNA1 have been reported to manifest as paroxysmal kinesigenic dyskinesia (PKD), but the correlation between them remains unclear due to the phenotypic complexity of KCNA1 variants as well as the rarity of PKD cases. Using the whole exome sequencing followed by Sanger sequencing, we screen for potential pathogenic KCNA1 variants in patients clinically diagnosed with paroxysmal movement disorders and identify three previously unreported missense variants of KCNA1 in three unrelated Chinese families. The proband of one family (c.496G>A, p.A166T) manifests as episodic ataxia type 1, and the other two (c.877G>A, p.V293I and c.1112C>A, p.T371A) manifest as PKD. The pathogenicity of these variants is confirmed by functional studies, suggesting that p.A166T and p.T371A cause a loss-of-function of the channel, while p.V293I leads to a gain-of-function with the property of voltage-dependent gating and activation kinetic affected. By reviewing the locations of PKD-manifested KCNA1 variants in Kv1.1 protein, we find that these variants tend to cluster around the pore domain, which is similar to epilepsy. Thus, our study strengthens the correlation between KCNA1 variants and PKD and provides more information on genotype-phenotype correlations of KCNA1 channelopathy.
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Affiliation(s)
- Wan-Bing Sun
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China
| | - Jing-Xin Fu
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Yu-Lan Chen
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Hong-Fu Li
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China
| | - Zhi-Ying Wu
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310012, China.
| | - Dian-Fu Chen
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310012, China.
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Wang W, Zhang Y, Li X, E Q, Jiang Z, Shi Q, Huang Y, Wang J, Huang Y. KCNA1 promotes the growth and invasion of glioblastoma cells through ferroptosis inhibition via upregulating SLC7A11. Cancer Cell Int 2024; 24:7. [PMID: 38172959 PMCID: PMC10765868 DOI: 10.1186/s12935-023-03199-9] [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: 10/13/2023] [Accepted: 12/27/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND The high invasiveness and infiltrative nature of Glioblastoma (GBM) pose significant challenges for surgical removal. This study aimed to investigate the role of KCNA1 in GBM progression. METHODS CCK8, colony formation assay, scratch assay, transwell assay, and 3D tumor spheroid invasion assays were to determine how KCNA1 affects the growth and invasion of GBM cells. Subsequently, to confirm the impact of KCNA1 in ferroptosis, western blot, transmission electron microscopy and flow cytometry were conducted. To ascertain the impact of KCNA1 in vivo, patient-derived orthotopic xenograft models were established. RESULTS In functional assays, KCNA1 promotes the growth and invasion of GBM cells. Besides, KCNA1 can increase the expression of SLC7A11 and protect cells from ferroptosis. The vivo experiments demonstrated that knocking down KCNA1 inhibited the growth and infiltration of primary tumors in mice and extended survival time. CONCLUSION Therefore, our research suggests that KCNA1 may promote tumor growth and invasion by upregulating the expression of SLC7A11 and inhibiting ferroptosis, making it a promising therapeutic target for GBM.
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Affiliation(s)
- Weichao Wang
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Yang Zhang
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, 215000, China
| | - Xuetao Li
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Qinzi E
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Zuoyu Jiang
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Qikun Shi
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Yu Huang
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China
| | - Jian Wang
- Department of Neurosurgery, TaiCang Hospital of Traditional Chinese Medicine, Suzhou, 215000, China.
| | - Yulun Huang
- Department of Neurosurgery, Dushu Lake Hospital Affiliated of Soochow University, Suzhou, 215000, China.
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, 215000, China.
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Borowicz-Reutt K, Czernia J, Krawczyk M. Genetic Background of Epilepsy and Antiepileptic Treatments. Int J Mol Sci 2023; 24:16280. [PMID: 38003469 PMCID: PMC10671416 DOI: 10.3390/ijms242216280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/01/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Advanced identification of the gene mutations causing epilepsy syndromes is expected to translate into faster diagnosis and more effective treatment of these conditions. Over the last 5 years, approximately 40 clinical trials on the treatment of genetic epilepsies have been conducted. As a result, some medications that are not regular antiseizure drugs (e.g., soticlestat, fenfluramine, or ganaxolone) have been introduced to the treatment of drug-resistant seizures in Dravet, Lennox-Gastaut, maternally inherited chromosome 15q11.2-q13.1 duplication (Dup 15q) syndromes, and protocadherin 19 (PCDH 19)-clusterig epilepsy. And although the effects of soticlestat, fenfluramine, and ganaxolone are described as promising, they do not significantly affect the course of the mentioned epilepsy syndromes. Importantly, each of these syndromes is related to mutations in several genes. On the other hand, several mutations can occur within one gene, and different gene variants may be manifested in different disease phenotypes. This complex pattern of inheritance contributes to rather poor genotype-phenotype correlations. Hence, the detection of a specific mutation is not synonymous with a precise diagnosis of a specific syndrome. Bearing in mind that seizures develop as a consequence of the predominance of excitatory over inhibitory processes, it seems reasonable that mutations in genes encoding sodium and potassium channels, as well as glutamatergic and gamma-aminobutyric (GABA) receptors, play a role in the pathogenesis of epilepsy. In some cases, different pathogenic variants of the same gene can result in opposite functional effects, determining the effectiveness of therapy with certain medications. For instance, seizures related to gain-of-function (GoF) mutations in genes encoding sodium channels can be successfully treated with sodium channel blockers. On the contrary, the same drugs may aggravate seizures related to loss-of-function (LoF) variants of the same genes. Hence, knowledge of gene mutation-treatment response relationships facilitates more favorable selection of drugs for anticonvulsant therapy.
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Affiliation(s)
- Kinga Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Toxicology, Medical University of Lublin, Jaczewskiego 8b, 20-090 Lublin, Poland; (J.C.); (M.K.)
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6
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Schlüter A, Vélez-Santamaría V, Verdura E, Rodríguez-Palmero A, Ruiz M, Fourcade S, Planas-Serra L, Launay N, Guilera C, Martínez JJ, Homedes-Pedret C, Albertí-Aguiló MA, Zulaika M, Martí I, Troncoso M, Tomás-Vila M, Bullich G, García-Pérez MA, Sobrido-Gómez MJ, López-Laso E, Fons C, Del Toro M, Macaya A, Beltran S, Gutiérrez-Solana LG, Pérez-Jurado LA, Aguilera-Albesa S, de Munain AL, Casasnovas C, Pujol A. ClinPrior: an algorithm for diagnosis and novel gene discovery by network-based prioritization. Genome Med 2023; 15:68. [PMID: 37679823 PMCID: PMC10486091 DOI: 10.1186/s13073-023-01214-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/24/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Whole-exome sequencing (WES) and whole-genome sequencing (WGS) have become indispensable tools to solve rare Mendelian genetic conditions. Nevertheless, there is still an urgent need for sensitive, fast algorithms to maximise WES/WGS diagnostic yield in rare disease patients. Most tools devoted to this aim take advantage of patient phenotype information for prioritization of genomic data, although are often limited by incomplete gene-phenotype knowledge stored in biomedical databases and a lack of proper benchmarking on real-world patient cohorts. METHODS We developed ClinPrior, a novel method for the analysis of WES/WGS data that ranks candidate causal variants based on the patient's standardized phenotypic features (in Human Phenotype Ontology (HPO) terms). The algorithm propagates the data through an interactome network-based prioritization approach. This algorithm was thoroughly benchmarked using a synthetic patient cohort and was subsequently tested on a heterogeneous prospective, real-world series of 135 families affected by hereditary spastic paraplegia (HSP) and/or cerebellar ataxia (CA). RESULTS ClinPrior successfully identified causative variants achieving a final positive diagnostic yield of 70% in our real-world cohort. This includes 10 novel candidate genes not previously associated with disease, 7 of which were functionally validated within this project. We used the knowledge generated by ClinPrior to create a specific interactome for HSP/CA disorders thus enabling future diagnoses as well as the discovery of novel disease genes. CONCLUSIONS ClinPrior is an algorithm that uses standardized phenotype information and interactome data to improve clinical genomic diagnosis. It helps in identifying atypical cases and efficiently predicts novel disease-causing genes. This leads to increasing diagnostic yield, shortening of the diagnostic Odysseys and advancing our understanding of human illnesses.
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Affiliation(s)
- Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Valentina Vélez-Santamaría
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Neurology Department, Neuromuscular Unit, Bellvitge University Hospital, Universitat de Barcelona, Barcelona, Spain
| | - Edgard Verdura
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Agustí Rodríguez-Palmero
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Unit, Pediatrics Department, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Stéphane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Laura Planas-Serra
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Nathalie Launay
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Cristina Guilera
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Juan José Martínez
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - Christian Homedes-Pedret
- Neurology Department, Neuromuscular Unit, Bellvitge University Hospital, Universitat de Barcelona, Barcelona, Spain
- Neurology Department, Hospital Universitari General de Catalunya, Barcelona, Spain
| | - M Antonia Albertí-Aguiló
- Neurology Department, Neuromuscular Unit, Bellvitge University Hospital, Universitat de Barcelona, Barcelona, Spain
| | - Miren Zulaika
- Neuromuscular Area, Group of Neurodegenerative Diseases, Biodonostia Health Research Institute (Biodonostia HRI), San Sebastian, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Itxaso Martí
- Neuromuscular Area, Group of Neurodegenerative Diseases, Biodonostia Health Research Institute (Biodonostia HRI), San Sebastian, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Pediatric Neurology Department, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Mónica Troncoso
- Pediatric Neurology Department, Central Campus, Hospital Clínico San Borja Arriarán, Universidad de Chile, Santiago, Chile
| | - Miguel Tomás-Vila
- Neuropediatrics Department, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Gemma Bullich
- Centro Nacional Análisis Genómico (CNAG) - Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Baldiri Reixac 4, Barcelona, Spain
| | - M Asunción García-Pérez
- Pediatric Neurology Unit, Pediatrics Department, Hospital Universitario Fundación Alcorcón, Madrid, Spain
| | - María-Jesús Sobrido-Gómez
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Coruña Institute of Biomedical Research (INIBIC), A Coruña, Spain
- Hospital Clínico Universitario, A Coruña, Spain
| | - Eduardo López-Laso
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Unit, Pediatrics Department, Reina Sofía University Hospital, Córdoba, Spain
- Maimonides Institute For Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain
| | - Carme Fons
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Department, Sant Joan de Déu University Hospital, Member of the ERN EpiCARE, Barcelona, Spain
- Sant Joan de Déu Research Institute, (IRSJD), Barcelona, Spain
| | - Mireia Del Toro
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Department, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain
- Pediatric Neurology Research Group, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Alfons Macaya
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Department, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain
- Pediatric Neurology Research Group, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sergi Beltran
- Centro Nacional Análisis Genómico (CNAG) - Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Baldiri Reixac 4, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Departament de Genètica, Facultat de Biologia, Microbiologia i Estadística, Universitat de Barcelona (UB), Barcelona, 08028, Spain
| | - Luis G Gutiérrez-Solana
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Pediatric Neurology Department, Children's University Hospital Niño Jesús, Madrid, Spain
| | - Luis A Pérez-Jurado
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
- Genetics Service, Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Sergio Aguilera-Albesa
- Pediatric Neurology Unit, Pediatrics Department, Navarra Health Service, Pamplona, Spain
- Navarrabiomed, Biomedical Research Center, Pamplona, Spain
| | - Adolfo López de Munain
- Neuromuscular Area, Group of Neurodegenerative Diseases, Biodonostia Health Research Institute (Biodonostia HRI), San Sebastian, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Neurology Department, Donostia University Hospital, San Sebastian, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain.
- Neurology Department, Neuromuscular Unit, Bellvitge University Hospital, Universitat de Barcelona, Barcelona, Spain.
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Hospital Duran i Reynals, Gran Via 199, L'Hospitalet de Llobregat, Barcelona, 08908, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain.
- Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Catalonia, Spain.
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Wang X, Mei D, Lu Z, Zhang Y, Sun Y, Lu T, Yan H, Yue W. Genome-wide association study identified six loci associated with adverse drug reactions to aripiprazole in schizophrenia patients. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2023; 9:44. [PMID: 37491364 PMCID: PMC10368716 DOI: 10.1038/s41537-023-00369-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/19/2023] [Indexed: 07/27/2023]
Abstract
Aripiprazole is recommended for routine use in schizophrenia patients. However, the biological mechanism for the adverse drug reactions (ADRs) among schizophrenia patients with the antipsychotic drug aripiprazole is far from clear. To explore the potential genetic factors that may cause movement-related adverse antipsychotic effects in patients, we conducted an association analysis between movement-related ADRs and SNPs in schizophrenia patients receiving aripiprazole monotherapy. In this study, multiple ADRs of 384 patients were quantified within 6-week treatment, and the scores of movement-related ADRs at baseline and follow-up time points during treatment were obtained. The highest score record was used as the quantitative index in analysis, and genetic analysis at the genome-wide level was conducted. The SNP rs4149181 in SLC22A8 [P = 2.28 × 10-8] showed genome-wide significance, and rs2284223 in ADCYAP1R1 [P = 9.76 × 10-8], rs73258503 in KCNIP4 [P = 1.39 × 10-7], rs678428 in SMAD9 [P = 4.70 × 10-7], rs6421034 in NAP1L4 [P = 6.80 × 10-7], and rs1394796 in ERBB4 [P = 8.60 × 10-7] were found to be significantly associated with movement-related ADRs. The combined prediction model of these six loci showed acceptable performance in predicting adverse events [area under the curve (AUC): 0.84]. Combined with the function and network of the above genes and other candidate loci (KCNA1, CACNG1, etc.), we hypothesize that SLC22A8 and KCNIP4-Kv channel perform their respective functions as transporter or channel and participate in the in vivo metabolism or effects of aripiprazole. The above results imply the important function of ion transporters and channels in movement-related adverse antipsychotic effects in aripiprazole monotherapy schizophrenia patients.
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Affiliation(s)
- Xueping Wang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China
| | - Dongli Mei
- School of Nursing, Peking University, 10019, Beijing, China
| | - Zhe Lu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China
| | - Yuyanan Zhang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China
| | - Yaoyao Sun
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China
| | - Tianlan Lu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China
| | - Hao Yan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China.
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China.
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China.
| | - Weihua Yue
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China.
- National Clinical Research Center for Mental Disorders & NHC Key Laboratory of Mental Health (Peking University), 100191, Beijing, China.
- Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No. 2018RU006), Beijing, China.
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China.
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Paulhus K, Glasscock E. Novel Genetic Variants Expand the Functional, Molecular, and Pathological Diversity of KCNA1 Channelopathy. Int J Mol Sci 2023; 24:8826. [PMID: 37240170 PMCID: PMC10219020 DOI: 10.3390/ijms24108826] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
The KCNA1 gene encodes Kv1.1 voltage-gated potassium channel α subunits, which are crucial for maintaining healthy neuronal firing and preventing hyperexcitability. Mutations in the KCNA1 gene can cause several neurological diseases and symptoms, such as episodic ataxia type 1 (EA1) and epilepsy, which may occur alone or in combination, making it challenging to establish simple genotype-phenotype correlations. Previous analyses of human KCNA1 variants have shown that epilepsy-linked mutations tend to cluster in regions critical for the channel's pore, whereas EA1-associated mutations are evenly distributed across the length of the protein. In this review, we examine 17 recently discovered pathogenic or likely pathogenic KCNA1 variants to gain new insights into the molecular genetic basis of KCNA1 channelopathy. We provide the first systematic breakdown of disease rates for KCNA1 variants in different protein domains, uncovering potential location biases that influence genotype-phenotype correlations. Our examination of the new mutations strengthens the proposed link between the pore region and epilepsy and reveals new connections between epilepsy-related variants, genetic modifiers, and respiratory dysfunction. Additionally, the new variants include the first two gain-of-function mutations ever discovered for KCNA1, the first frameshift mutation, and the first mutations located in the cytoplasmic N-terminal domain, broadening the functional and molecular scope of KCNA1 channelopathy. Moreover, the recently identified variants highlight emerging links between KCNA1 and musculoskeletal abnormalities and nystagmus, conditions not typically associated with KCNA1. These findings improve our understanding of KCNA1 channelopathy and promise to enhance personalized diagnosis and treatment for individuals with KCNA1-linked disorders.
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Affiliation(s)
| | - Edward Glasscock
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA;
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9
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Salpietro V, Galassi Deforie V, Efthymiou S, O'Connor E, Marcé‐Grau A, Maroofian R, Striano P, Zara F, Morrow MM, Reich A, Blevins A, Sala‐Coromina J, Accogli A, Fortuna S, Alesandrini M, Au PYB, Singhal NS, Cogne B, Isidor B, Hanna MG, Macaya A, Kullmann DM, Houlden H, Männikkö R. De novo KCNA6 variants with attenuated K V 1.6 channel deactivation in patients with epilepsy. Epilepsia 2023; 64:443-455. [PMID: 36318112 PMCID: PMC10108282 DOI: 10.1111/epi.17455] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Mutations in the genes encoding neuronal ion channels are a common cause of Mendelian neurological diseases. We sought to identify novel de novo sequence variants in cases with early infantile epileptic phenotypes and neurodevelopmental anomalies. METHODS Following clinical diagnosis, we performed whole exome sequencing of the index cases and their parents. Identified channel variants were expressed in Xenopus oocytes and their functional properties assessed using two-electrode voltage clamp. RESULTS We identified novel de novo variants in KCNA6 in four unrelated individuals variably affected with neurodevelopmental disorders and seizures with onset in the first year of life. Three of the four identified mutations affect the pore-lining S6 α-helix of KV 1.6. A prominent finding of functional characterization in Xenopus oocytes was that the channel variants showed only minor effects on channel activation but slowed channel closure and shifted the voltage dependence of deactivation in a hyperpolarizing direction. Channels with a mutation affecting the S6 helix display dominant effects on channel deactivation when co-expressed with wild-type KV 1.6 or KV 1.1 subunits. SIGNIFICANCE This is the first report of de novo nonsynonymous variants in KCNA6 associated with neurological or any clinical features. Channel variants showed a consistent effect on channel deactivation, slowing the rate of channel closure following normal activation. This specific gain-of-function feature is likely to underlie the neurological phenotype in our patients. Our data highlight KCNA6 as a novel channelopathy gene associated with early infantile epileptic phenotypes and neurodevelopmental anomalies.
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Affiliation(s)
- Vincenzo Salpietro
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Department of Biotechnological and Applied Clinical Sciences (DISCAB)University of L'AquilaL'AquilaItaly
| | | | - Stephanie Efthymiou
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Emer O'Connor
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Anna Marcé‐Grau
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Reza Maroofian
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Unit of Pediatric NeurologyIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | | | | | | | - Júlia Sala‐Coromina
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Andrea Accogli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | - Marie Alesandrini
- Neuropediatrics UnitCentre Hospitalier Universitaire NantesNantesFrance
| | - P. Y. Billie Au
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of MedicineUniversity of CalgaryAlbertaCalgaryCanada
| | - Nilika Shah Singhal
- Departments of Neurology and Pediatrics, UCSF Benioff Children's HospitalUniversity of CaliforniaCaliforniaSan FranciscoUSA
| | - Benjamin Cogne
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Bertrand Isidor
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Michael G. Hanna
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Queen Square Centre for Neuromuscular DiseasesNational Hospital for Neurology and NeurosurgeryLondonUK
| | - Alfons Macaya
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Dimitri M. Kullmann
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, University College LondonLondonUK
| | - Henry Houlden
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Roope Männikkö
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
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10
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Garg D, Mohammad S, Shukla A, Sharma S. Genetic Links to Episodic Movement Disorders: Current Insights. Appl Clin Genet 2023; 16:11-30. [PMID: 36883047 PMCID: PMC9985884 DOI: 10.2147/tacg.s363485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
Episodic or paroxysmal movement disorders (PxMD) are conditions, which occur episodically, are transient, usually have normal interictal periods, and are characterized by hyperkinetic disorders, including ataxia, chorea, dystonia, and ballism. Broadly, these comprise paroxysmal dyskinesias (paroxysmal kinesigenic and non-kinesigenic dyskinesia [PKD/PNKD], paroxysmal exercise-induced dyskinesias [PED]) and episodic ataxias (EA) types 1-9. Classification of paroxysmal dyskinesias has traditionally been clinical. However, with advancement in genetics and the discovery of the molecular basis of several of these disorders, it is becoming clear that phenotypic pleiotropy exists, that is, the same variant may give rise to a variety of phenotypes, and the classical understanding of these disorders requires a new paradigm. Based on molecular pathogenesis, paroxysmal disorders are now categorized as synaptopathies, transportopathies, channelopathies, second-messenger related disorders, mitochondrial or others. A genetic paradigm also has an advantage of identifying potentially treatable disorders, such as glucose transporter 1 deficiency syndromes, which necessitates a ketogenic diet, and ADCY5-related disorders, which may respond to caffeine. Clues for a primary etiology include age at onset below 18 years, presence of family history and fixed triggers and attack duration. Paroxysmal movement disorder is a network disorder, with both the basal ganglia and the cerebellum implicated in pathogenesis. Abnormalities in the striatal cAMP turnover pathway may also be contributory. Although next-generation sequencing has restructured the approach to paroxysmal movement disorders, the genetic underpinnings of several entities remain undiscovered. As more genes and variants continue to be reported, these will lead to enhanced understanding of pathophysiological mechanisms and precise treatment.
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Affiliation(s)
- Divyani Garg
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Shekeeb Mohammad
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, The University of Sydney, Westmead, New South Wales, Australia
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College and Hospital, Manipal, India
| | - Suvasini Sharma
- Department of Pediatrics (Neurology Division), Lady Hardinge Medical College and Kalawati Saran Hospital, New Delhi, India
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11
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Dinoi G, Morin M, Conte E, Mor Shaked H, Coppola MA, D’Adamo MC, Elpeleg O, Liantonio A, Hartmann I, De Luca A, Blunck R, Russo A, Imbrici P. Clinical and Functional Study of a De Novo Variant in the PVP Motif of Kv1.1 Channel Associated with Epilepsy, Developmental Delay and Ataxia. Int J Mol Sci 2022; 23:ijms23158079. [PMID: 35897654 PMCID: PMC9331732 DOI: 10.3390/ijms23158079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 02/05/2023] Open
Abstract
Mutations in the KCNA1 gene, encoding the voltage-gated potassium channel Kv1.1, have been associated with a spectrum of neurological phenotypes, including episodic ataxia type 1 and developmental and epileptic encephalopathy. We have recently identified a de novo variant in KCNA1 in the highly conserved Pro-Val-Pro motif within the pore of the Kv1.1 channel in a girl affected by early onset epilepsy, ataxia and developmental delay. Other mutations causing severe epilepsy are located in Kv1.1 pore domain. The patient was initially treated with a combination of antiepileptic drugs with limited benefit. Finally, seizures and ataxia control were achieved with lacosamide and acetazolamide. The aim of this study was to functionally characterize Kv1.1 mutant channel to provide a genotype–phenotype correlation and discuss therapeutic options for KCNA1-related epilepsy. To this aim, we transfected HEK 293 cells with Kv1.1 or P403A cDNAs and recorded potassium currents through whole-cell patch-clamp. P403A channels showed smaller potassium currents, voltage-dependent activation shifted by +30 mV towards positive potentials and slower kinetics of activation compared with Kv1.1 wild-type. Heteromeric Kv1.1+P403A channels, resembling the condition of the heterozygous patient, confirmed a loss-of-function biophysical phenotype. Overall, the functional characterization of P403A channels correlates with the clinical symptoms of the patient and supports the observation that mutations associated with severe epileptic phenotype cluster in a highly conserved stretch of residues in Kv1.1 pore domain. This study also strengthens the beneficial effect of acetazolamide and sodium channel blockers in KCNA1 channelopathies.
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Affiliation(s)
- Giorgia Dinoi
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
| | - Michael Morin
- Department of Physics, Université de Montréal, Montreal, QC H3C 3J7, Canada; (M.M.); (R.B.)
- CIRCA, Center for Interdisciplinary Research on Brain and Learning, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
| | - Hagar Mor Shaked
- Department of Genetics, Hadassah Medical Center, Jerusalem 91120, Israel; (H.M.S.); (O.E.)
| | - Maria Antonietta Coppola
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
| | | | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem 91120, Israel; (H.M.S.); (O.E.)
| | - Antonella Liantonio
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
| | - Inbar Hartmann
- Pediatric Neurology Clinic, Shamir Medical Center (Assaf Harofeh), Zerifin 7033001, Israel;
| | - Annamaria De Luca
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
| | - Rikard Blunck
- Department of Physics, Université de Montréal, Montreal, QC H3C 3J7, Canada; (M.M.); (R.B.)
- CIRCA, Center for Interdisciplinary Research on Brain and Learning, Université de Montréal, Montreal, QC H3C 3J7, Canada
- Department of Pharmacology and Physiology, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Angelo Russo
- Child Neurology Unit, IRCCS, Institute of Neurological Sciences of Bologna, 40139 Bologna, Italy;
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (G.D.); (E.C.); (M.A.C.); (A.L.); (A.D.L.)
- Correspondence:
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12
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Bhattacharjee S, Deenadayalu A, Paramanandam V. Interictal Headache, Pseudodystonia, and Persistent Ataxia in Episodic Ataxia Type 1 Due to a Novel
KCNA1
Gene Mutation. Mov Disord Clin Pract 2021; 9:272-274. [DOI: 10.1002/mdc3.13381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 11/07/2022] Open
Affiliation(s)
- Shakya Bhattacharjee
- Autonomic Neurology The National Hospital for Neurology & Neurosurgery London United Kingdom
| | - Anu Deenadayalu
- Internal Medicine Limerick University Hospital Limerick Ireland
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13
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Aiba I, Noebels JL. Kcnq2/Kv7.2 controls the threshold and bi-hemispheric symmetry of cortical spreading depolarization. Brain 2021; 144:2863-2878. [PMID: 33768249 PMCID: PMC8536937 DOI: 10.1093/brain/awab141] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/22/2021] [Accepted: 03/20/2021] [Indexed: 12/03/2022] Open
Abstract
Spreading depolarization is a slowly propagating wave of massive cellular depolarization associated with acute brain injury and migraine aura. Genetic studies link depolarizing molecular defects in Ca2+ flux, Na+ current in interneurons, and glial Na+-K+ ATPase with spreading depolarization susceptibility, emphasizing the important roles of synaptic activity and extracellular ionic homeostasis in determining spreading depolarization threshold. In contrast, although gene mutations in voltage-gated potassium ion channels that shape intrinsic membrane excitability are frequently associated with epilepsy susceptibility, it is not known whether epileptogenic mutations that regulate membrane repolarization also modify spreading depolarization threshold and propagation. Here we report that the Kcnq2/Kv7.2 potassium channel subunit, frequently mutated in developmental epilepsy, is a spreading depolarization modulatory gene with significant control over the seizure-spreading depolarization transition threshold, bi-hemispheric cortical expression, and diurnal temporal susceptibility. Chronic DC-band cortical EEG recording from behaving conditional Kcnq2 deletion mice (Emx1cre/+::Kcnq2flox/flox) revealed spontaneous cortical seizures and spreading depolarization. In contrast to the related potassium channel deficient model, Kv1.1-KO mice, spontaneous cortical spreading depolarizations in Kcnq2 cKO mice are tightly coupled to the terminal phase of seizures, arise bilaterally, and are observed predominantly during the dark phase. Administration of the non-selective Kv7.2 inhibitor XE991 to Kv1.1-KO mice partly reproduced the Kcnq2 cKO-like spreading depolarization phenotype (tight seizure coupling and bilateral symmetry) in these mice, indicating that Kv7.2 currents can directly and actively modulate spreading depolarization properties. In vitro brain slice studies confirmed that Kcnq2/Kv7.2 depletion or pharmacological inhibition intrinsically lowers the cortical spreading depolarization threshold, whereas pharmacological Kv7.2 activators elevate the threshold to multiple depolarizing and hypometabolic spreading depolarization triggers. Together these results identify Kcnq2/Kv7.2 as a distinctive spreading depolarization regulatory gene, and point to spreading depolarization as a potentially significant pathophysiological component of KCNQ2-linked epileptic encephalopathy syndromes. Our results also implicate KCNQ2/Kv7.2 channel activation as a potential adjunctive therapeutic target to inhibit spreading depolarization incidence.
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Affiliation(s)
- Isamu Aiba
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jeffrey L Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
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14
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Harvey S, King MD, Gorman KM. Paroxysmal Movement Disorders. Front Neurol 2021; 12:659064. [PMID: 34177764 PMCID: PMC8232056 DOI: 10.3389/fneur.2021.659064] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/20/2021] [Indexed: 11/13/2022] Open
Abstract
Paroxysmal movement disorders (PxMDs) are a clinical and genetically heterogeneous group of movement disorders characterized by episodic involuntary movements (dystonia, dyskinesia, chorea and/or ataxia). Historically, PxMDs were classified clinically (triggers and characteristics of the movements) and this directed single-gene testing. With the advent of next-generation sequencing (NGS), how we classify and investigate PxMDs has been transformed. Next-generation sequencing has enabled new gene discovery (RHOBTB2, TBC1D24), expansion of phenotypes in known PxMDs genes and a better understanding of disease mechanisms. However, PxMDs exhibit phenotypic pleiotropy and genetic heterogeneity, making it challenging to predict genotype based on the clinical phenotype. For example, paroxysmal kinesigenic dyskinesia is most commonly associated with variants in PRRT2 but also variants identified in PNKD, SCN8A, and SCL2A1. There are no radiological or biochemical biomarkers to differentiate genetic causes. Even with NGS, diagnosis rates are variable, ranging from 11 to 51% depending on the cohort studied and technology employed. Thus, a large proportion of patients remain undiagnosed compared to other neurological disorders such as epilepsy, highlighting the need for further genomic research in PxMDs. Whole-genome sequencing, deep-sequencing, copy number variant analysis, detection of deep-intronic variants, mosaicism and repeat expansions, will improve diagnostic rates. Identifying the underlying genetic cause has a significant impact on patient care, modification of treatment, long-term prognostication and genetic counseling. This paper provides an update on the genetics of PxMDs, description of PxMDs classified according to causative gene rather than clinical phenotype, highlighting key clinical features and providing an algorithm for genetic testing of PxMDs.
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Affiliation(s)
- Susan Harvey
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Kathleen M Gorman
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
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15
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Indumathy J, Pruitt A, Gautier NM, Crane K, Glasscock E. Kv1.1 deficiency alters repetitive and social behaviors in mice and rescues autistic-like behaviors due to Scn2a haploinsufficiency. Brain Behav 2021; 11:e02041. [PMID: 33484493 PMCID: PMC8035482 DOI: 10.1002/brb3.2041] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/29/2020] [Accepted: 12/31/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Autism spectrum disorder (ASD) and epilepsy are highly comorbid, suggesting potential overlap in genetic etiology, pathophysiology, and neurodevelopmental abnormalities; however, the nature of this relationship remains unclear. This work investigated how two ion channel mutations, one associated with autism (Scn2a-null) and one with epilepsy (Kcna1-null), interact to modify genotype-phenotype relationships in the context of autism. Previous studies have shown that Scn2a+/- ameliorates epilepsy in Kcna1-/- mice, improving survival, seizure characteristics, and brain-heart dynamics. Here, we tested the converse, whether Kcna1 deletion modifies ASD-like repetitive and social behaviors in Scn2a+/- mice. METHODS Mice were bred with various combinations of Kcna1 and Scn2a knockout alleles. Animals were assessed for repetitive behaviors using marble burying, grooming, and nestlet shredding tests and for social behaviors using sociability and social novelty preference tests. RESULTS Behavioral testing revealed drastic reductions in all repetitive behaviors in epileptic Kcna1-/- mice, but relatively normal social interactions. In contrast, mice with partial Kcna1 deletion (Kcna1+/- ) exhibited increased self-grooming and decreased sociability suggestive of ASD-like features similar to those observed in Scn2a+/- mice. In double-mutant Scn2a+/- ; Kcna1+/- mice, the two mutations interacted to partially normalize ASD-like behaviors associated with each mutation independently. CONCLUSIONS Taken together, these findings suggest that Kv1.1 subunits are important in pathways and neural networks underlying ASD and that Kcna1 may be a therapeutic target for treatment of Scn2a-associated ASD.
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Affiliation(s)
- Jagadeeswaran Indumathy
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLAUSA
- Present address:
Department of Biological SciencesSouthern Methodist UniversityDallasTXUSA
| | - April Pruitt
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLAUSA
| | - Nicole M. Gautier
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLAUSA
| | - Kaitlin Crane
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLAUSA
| | - Edward Glasscock
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLAUSA
- Present address:
Department of Biological SciencesSouthern Methodist UniversityDallasTXUSA
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de Gusmão CM, Garcia L, Mikati MA, Su S, Silveira-Moriyama L. Paroxysmal Genetic Movement Disorders and Epilepsy. Front Neurol 2021; 12:648031. [PMID: 33833732 PMCID: PMC8021799 DOI: 10.3389/fneur.2021.648031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/22/2021] [Indexed: 01/08/2023] Open
Abstract
Paroxysmal movement disorders include paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia, and episodic ataxias. In recent years, there has been renewed interest and recognition of these disorders and their intersection with epilepsy, at the molecular and pathophysiological levels. In this review, we discuss how these distinct phenotypes were constructed from a historical perspective and discuss how they are currently coalescing into established genetic etiologies with extensive pleiotropy, emphasizing clinical phenotyping important for diagnosis and for interpreting results from genetic testing. We discuss insights on the pathophysiology of select disorders and describe shared mechanisms that overlap treatment principles in some of these disorders. In the near future, it is likely that a growing number of genes will be described associating movement disorders and epilepsy, in parallel with improved understanding of disease mechanisms leading to more effective treatments.
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Affiliation(s)
- Claudio M. de Gusmão
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
| | - Lucas Garcia
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
| | - Mohamad A. Mikati
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Samantha Su
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Laura Silveira-Moriyama
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
- Education Unit, University College London Institute of Neurology, University College London, London, United Kingdom
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Musculoskeletal Features without Ataxia Associated with a Novel de novo Mutation in KCNA1 Impairing the Voltage Sensitivity of Kv1.1 Channel. Biomedicines 2021; 9:biomedicines9010075. [PMID: 33466780 PMCID: PMC7829709 DOI: 10.3390/biomedicines9010075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/02/2021] [Accepted: 01/06/2021] [Indexed: 02/06/2023] Open
Abstract
The KCNA1 gene encodes the α subunit of the voltage-gated Kv1.1 potassium channel that critically regulates neuronal excitability in the central and peripheral nervous systems. Mutations in KCNA1 have been classically associated with episodic ataxia type 1 (EA1), a movement disorder triggered by physical and emotional stress. Additional features variably reported in recent years include epilepsy, myokymia, migraine, paroxysmal dyskinesia, hyperthermia, hypomagnesemia, and cataplexy. Interestingly, a few individuals with neuromyotonia, either isolated or associated with skeletal deformities, have been reported carrying variants in the S2–S3 transmembrane segments of Kv1.1 channels in the absence of any other symptoms. Here, we have identified by whole-exome sequencing a novel de novo variant, T268K, in KCNA1 in a boy displaying recurrent episodes of neuromyotonia, muscle hypertrophy, and skeletal deformities. Through functional analysis in heterologous cells and structural modeling, we show that the mutation, located at the extracellular end of the S3 helix, causes deleterious effects, disrupting Kv1.1 function by altering the voltage dependence of activation and kinetics of deactivation, likely due to abnormal interactions with the voltage sensor in the S4 segment. Our study supports previous evidence suggesting that specific residues within the S2 and S3 segments of Kv1.1 result in a distinctive phenotype with predominant musculoskeletal presentation.
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Yuan H, Yuan H, Wang Q, Ye W, Yao R, Xu W, Liu Y. Two novel KCNA1 variants identified in two unrelated Chinese families affected by episodic ataxia type 1 and neurodevelopmental disorders. Mol Genet Genomic Med 2020; 8:e1434. [PMID: 32705822 PMCID: PMC7549609 DOI: 10.1002/mgg3.1434] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/03/2020] [Accepted: 07/11/2020] [Indexed: 12/19/2022] Open
Abstract
Background Pathogenic KCNA1 variants have been linked to episodic ataxia type 1 (EA1), a rare neurological syndrome characterized by continuous myokymia and attacks of generalized ataxia that can be triggered by fever, abrupt movements, emotional stress, and fatigue. Currently, over 40 KCNA1 variants have been identified in individuals with EA1. Methods A male patient displayed partial seizures in addition to EA1 symptoms, often triggered by fever. A sibling presented with typical EA1 symptoms, seizures, and learning difficulties. In addition, the older brother displayed cognitive impairment, developmental delay, and slurred speech, which were absent in his younger sister. Whole‐exome sequencing was performed for the patients. Results A novel de novo missense variant in KCNA1 (p.Ala261Thr) was identified in the male patient, which is located in a base of the 3rd transmembrane domain (S3). The other novel KCNA1 variant (p.Gly376Ser) was identified in the sibling and was inherited from an unaffected father with low‐level mosaicism. The variant was located in the S5–S6 extracellular linker of the voltage sensor domain of the Kv channel. Next, we systematically reviewed the available clinical phenotypes of individuals with EA1 and observed that individuals with KCNA1 variants at the C‐terminus were more likely to suffer from seizures and neurodevelopmental disorders than those with variants at the N‐terminus. Conclusion Our study expands the mutation spectrum of KCNA1 and improves our understanding of the genotype–phenotype correlations of KCNA1. Definitive genetic diagnosis is beneficial for the genetic counseling and clinical management of individuals with EA1.
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Affiliation(s)
- Haiming Yuan
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
| | - Huihua Yuan
- Dongguan Maternal and Child Health Care HospitalDongguanChina
| | - Qingming Wang
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
| | - Wanhua Ye
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
| | - Ruixia Yao
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
| | - Wanfang Xu
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
| | - Yanhui Liu
- Dongguan Maternal and Child Health Care HospitalDongguanChina
- Dongguan Institute of Reproductive and Genetic ResearchDongguanChina
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D'Adamo MC, Liantonio A, Conte E, Pessia M, Imbrici P. Ion Channels Involvement in Neurodevelopmental Disorders. Neuroscience 2020; 440:337-359. [PMID: 32473276 DOI: 10.1016/j.neuroscience.2020.05.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/14/2022]
Abstract
Inherited and sporadic mutations in genes encoding for brain ion channels, affecting membrane expression or biophysical properties, have been associated with neurodevelopmental disorders characterized by epilepsy, cognitive and behavioral deficits with significant phenotypic and genetic heterogeneity. Over the years, the screening of a growing number of patients and the functional characterization of newly identified mutations in ion channels genes allowed to recognize new phenotypes and to widen the clinical spectrum of known diseases. Furthermore, advancements in understanding disease pathogenesis at atomic level or using patient-derived iPSCs and animal models have been pivotal to orient therapeutic intervention and to put the basis for the development of novel pharmacological options for drug-resistant disorders. In this review we will discuss major improvements and critical issues concerning neurodevelopmental disorders caused by dysfunctions in brain sodium, potassium, calcium, chloride and ligand-gated ion channels.
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Affiliation(s)
- Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | | | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta; Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy.
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20
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Kundap UP, Paudel YN, Shaikh MF. Animal Models of Metabolic Epilepsy and Epilepsy Associated Metabolic Dysfunction: A Systematic Review. Pharmaceuticals (Basel) 2020; 13:ph13060106. [PMID: 32466498 PMCID: PMC7345684 DOI: 10.3390/ph13060106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a serious neurological disorder affecting around 70 million people globally and is characterized by spontaneous recurrent seizures. Recent evidence indicates that dysfunction in metabolic processes can lead to the alteration of neuronal and network excitability, thereby contributing to epileptogenesis. Developing a suitable animal model that can recapitulate all the clinical phenotypes of human metabolic epilepsy (ME) is crucial yet challenging. The specific environment of many symptoms as well as the primary state of the applicable neurobiology, genetics, and lack of valid biomarkers/diagnostic tests are the key factors that hinder the process of developing a suitable animal model. The present systematic review summarizes the current state of available animal models of metabolic dysfunction associated with epileptic disorders. A systematic search was performed by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model. A range of electronic databases, including google scholar, Springer, PubMed, ScienceDirect, and Scopus, were scanned between January 2000 and April 2020. Based on the selection criteria, 23 eligible articles were chosen and are discussed in the current review. Critical analysis of the selected literature delineated several available approaches that have been modeled into metabolic epilepsy and pointed out several drawbacks associated with the currently available models. The result describes available models of metabolic dysfunction associated with epileptic disorder, such as mitochondrial respiration deficits, Lafora disease (LD) model-altered glycogen metabolism, causing epilepsy, glucose transporter 1 (GLUT1) deficiency, adiponectin responsive seizures, phospholipid dysfunction, glutaric aciduria, mitochondrial disorders, pyruvate dehydrogenase (PDH) α-subunit gene (PDHA1), pyridoxine dependent epilepsy (PDE), BCL2-associated agonist of cell death (BAD), Kcna1 knock out (KO), and long noncoding RNAs (lncRNA) cancer susceptibility candidate 2 (lncRNA CASC2). Finally, the review highlights certain focus areas that may increase the possibilities of developing more suitable animal models and underscores the importance of the rationalization of animal models and evaluation methods for studying ME. The review also suggests the pressing need of developing precise robust animal models and evaluation methods for investigating ME.
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Affiliation(s)
- Uday Praful Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
| | - Yam Nath Paudel
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
- Correspondence: ; Tel.: +60-3-551-44-483
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21
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Chow CY, Absalom N, Biggs K, King GF, Ma L. Venom-derived modulators of epilepsy-related ion channels. Biochem Pharmacol 2020; 181:114043. [PMID: 32445870 DOI: 10.1016/j.bcp.2020.114043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Epilepsy is characterised by spontaneous recurrent seizures that are caused by an imbalance between neuronal excitability and inhibition. Since ion channels play fundamental roles in the generation and propagation of action potentials as well as neurotransmitter release at a subset of excitatory and inhibitory synapses, their dysfunction has been linked to a wide variety of epilepsies. Indeed, these unique proteins are the major biological targets for antiepileptic drugs. Selective targeting of a specific ion channel subtype remains challenging for small molecules, due to the high level of homology among members of the same channel family. As a consequence, there is a growing trend to target ion channels with biologics. Venoms are the best known natural source of ion channel modulators, and venom peptides are increasingly recognised as potential therapeutics due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Here we describe the major ion channel families involved in the pathogenesis of various types of epilepsy, including voltage-gated Na+, K+, Ca2+ channels, Cys-loop receptors, ionotropic glutamate receptors and P2X receptors, and currently available venom-derived peptides that target these channel proteins. Although only a small number of venom peptides have successfully progressed to the clinic, there is reason to be optimistic about their development as antiepileptic drugs, notwithstanding the challenges associated with development of any class of peptide drug.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nathan Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kimberley Biggs
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia.
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22
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Clinical and Genetic Overview of Paroxysmal Movement Disorders and Episodic Ataxias. Int J Mol Sci 2020; 21:ijms21103603. [PMID: 32443735 PMCID: PMC7279391 DOI: 10.3390/ijms21103603] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/15/2022] Open
Abstract
Paroxysmal movement disorders (PMDs) are rare neurological diseases typically manifesting with intermittent attacks of abnormal involuntary movements. Two main categories of PMDs are recognized based on the phenomenology: Paroxysmal dyskinesias (PxDs) are characterized by transient episodes hyperkinetic movement disorders, while attacks of cerebellar dysfunction are the hallmark of episodic ataxias (EAs). From an etiological point of view, both primary (genetic) and secondary (acquired) causes of PMDs are known. Recognition and diagnosis of PMDs is based on personal and familial medical history, physical examination, detailed reconstruction of ictal phenomenology, neuroimaging, and genetic analysis. Neurophysiological or laboratory tests are reserved for selected cases. Genetic knowledge of PMDs has been largely incremented by the advent of next generation sequencing (NGS) methodologies. The wide number of genes involved in the pathogenesis of PMDs reflects a high complexity of molecular bases of neurotransmission in cerebellar and basal ganglia circuits. In consideration of the broad genetic and phenotypic heterogeneity, a NGS approach by targeted panel for movement disorders, clinical or whole exome sequencing should be preferred, whenever possible, to a single gene approach, in order to increase diagnostic rate. This review is focused on clinical and genetic features of PMDs with the aim to (1) help clinicians to recognize, diagnose and treat patients with PMDs as well as to (2) provide an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.
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23
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D’Adamo MC, Liantonio A, Rolland JF, Pessia M, Imbrici P. Kv1.1 Channelopathies: Pathophysiological Mechanisms and Therapeutic Approaches. Int J Mol Sci 2020; 21:ijms21082935. [PMID: 32331416 PMCID: PMC7215777 DOI: 10.3390/ijms21082935] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 12/27/2022] Open
Abstract
Kv1.1 belongs to the Shaker subfamily of voltage-gated potassium channels and acts as a critical regulator of neuronal excitability in the central and peripheral nervous systems. KCNA1 is the only gene that has been associated with episodic ataxia type 1 (EA1), an autosomal dominant disorder characterized by ataxia and myokymia and for which different and variable phenotypes have now been reported. The iterative characterization of channel defects at the molecular, network, and organismal levels contributed to elucidating the functional consequences of KCNA1 mutations and to demonstrate that ataxic attacks and neuromyotonia result from cerebellum and motor nerve alterations. Dysfunctions of the Kv1.1 channel have been also associated with epilepsy and kcna1 knock-out mouse is considered a model of sudden unexpected death in epilepsy. The tissue-specific association of Kv1.1 with other Kv1 members, auxiliary and interacting subunits amplifies Kv1.1 physiological roles and expands the pathogenesis of Kv1.1-associated diseases. In line with the current knowledge, Kv1.1 has been proposed as a novel and promising target for the treatment of brain disorders characterized by hyperexcitability, in the attempt to overcome limited response and side effects of available therapies. This review recounts past and current studies clarifying the roles of Kv1.1 in and beyond the nervous system and its contribution to EA1 and seizure susceptibility as well as its wide pharmacological potential.
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Affiliation(s)
- Maria Cristina D’Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
| | - Antonella Liantonio
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
| | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain Po Box 17666, UAE
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
- Correspondence:
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24
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Clinical Spectrum of KCNA1 Mutations: New Insights into Episodic Ataxia and Epilepsy Comorbidity. Int J Mol Sci 2020; 21:ijms21082802. [PMID: 32316562 PMCID: PMC7215408 DOI: 10.3390/ijms21082802] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the KCNA1 gene, which encodes voltage-gated Kv1.1 potassium channel α-subunits, cause a variety of human diseases, complicating simple genotype–phenotype correlations in patients. KCNA1 mutations are primarily associated with a rare neurological movement disorder known as episodic ataxia type 1 (EA1). However, some patients have EA1 in combination with epilepsy, whereas others have epilepsy alone. KCNA1 mutations can also cause hypomagnesemia and paroxysmal dyskinesia in rare cases. Why KCNA1 variants are associated with such phenotypic heterogeneity in patients is not yet understood. In this review, literature databases (PubMed) and public genetic archives (dbSNP and ClinVar) were mined for known pathogenic or likely pathogenic mutations in KCNA1 to examine whether patterns exist between mutation type and disease manifestation. Analyses of the 47 deleterious KCNA1 mutations that were identified revealed that epilepsy or seizure-related variants tend to cluster in the S1/S2 transmembrane domains and in the pore region of Kv1.1, whereas EA1-associated variants occur along the whole length of the protein. In addition, insights from animal models of KCNA1 channelopathy were considered, as well as the possible influence of genetic modifiers on disease expressivity and severity. Elucidation of the complex relationship between KCNA1 variants and disease will enable better diagnostic risk assessment and more personalized therapeutic strategies for KCNA1 channelopathy.
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25
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Manville RW, Abbott GW. Isoform-Selective KCNA1 Potassium Channel Openers Built from Glycine. J Pharmacol Exp Ther 2020; 373:391-401. [PMID: 32217768 DOI: 10.1124/jpet.119.264507] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/24/2020] [Indexed: 12/18/2022] Open
Abstract
Loss of function of voltage-gated potassium (Kv) channels is linked to a range of lethal or debilitating channelopathies. New pharmacological approaches are warranted to isoform-selectively activate specific Kv channels. One example is KCNA1 Potassium Voltage-Gated Channel Subfamily A Member 1 (KCNA1) (Kv1.1), an archetypal Shaker-type Kv channel, in which loss-of-function mutations cause episodic ataxia type 1 (EA1). EA1 causes constant myokomia and episodic bouts of ataxia and may associate with epilepsy and other disorders. We previously found that the inhibitory neurotransmitter γ-aminobutyric acid and modified versions of glycine directly activate Kv channels within the KCNQ subfamily, a characteristic favored by strong negative electrostatic surface potential near the neurotransmitter carbonyl group. Here, we report that adjusting the number and positioning of fluorine atoms within the fluorophenyl ring of glycine derivatives produces isoform-selective KCNA1 channel openers that are inactive against KCNQ2/3 channels, or even KCNA2, the closest relative of KCNA1. The findings refine our understanding of the molecular basis for KCNQ versus KCNA1 activation and isoform selectivity and constitute, to our knowledge, the first reported isoform-selective KCNA1 opener. SIGNIFICANCE STATEMENT: Inherited loss-of-function gene sequence variants in KCNA1, which encodes the KCNA1 (Kv1.1) voltage-gated potassium channel, cause episodic ataxia type 1 (EA1), a movement disorder also linked to epilepsy and developmental delay. We have discovered several isoform-specific KCNA1-activating small molecules, addressing a notable gap in the field and providing possible lead compounds and a novel chemical space for the development of potential future therapeutic drugs for EA1.
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Affiliation(s)
- Rían W Manville
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, California
| | - Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, California
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Wang X, Li G, Guo J, Zhang Z, Zhang S, Zhu Y, Cheng J, Yu L, Ji Y, Tao J. Kv1.3 Channel as a Key Therapeutic Target for Neuroinflammatory Diseases: State of the Art and Beyond. Front Neurosci 2020; 13:1393. [PMID: 31992966 PMCID: PMC6971160 DOI: 10.3389/fnins.2019.01393] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/10/2019] [Indexed: 12/26/2022] Open
Abstract
It remains a challenge for the effective treatment of neuroinflammatory disease, including multiple sclerosis (MS), stroke, epilepsy, and Alzheimer’s and Parkinson’s disease. The voltage-gated potassium Kv1.3 channel is of interest, which is considered as a novel therapeutic target for treating neuroinflammatory disorders due to its crucial role in subsets of T lymphocytes as well as microglial cells. Toxic animals, such as sea anemones, scorpions, spiders, snakes, and cone snails, can produce a variety of toxins that act on the Kv1.3 channel. The Stichodactyla helianthus K+ channel blocking toxin (ShK) from the sea anemone S. helianthus is proved as a classical blocker of Kv1.3. One of the synthetic analogs ShK-186, being developed as a therapeutic for autoimmune diseases, has successfully completed first-in-man Phase 1 trials. In addition to addressing the recent progress on the studies underlying the pharmacological characterizations of ShK on MS, the review will also explore the possibility for clinical treatment of ShK-like Kv1.3 blocking polypeptides on other neuroinflammatory diseases.
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Affiliation(s)
- Xiaoli Wang
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China,Institute of Biomembrane and Biopharmaceutics, Shanghai University, Shanghai, China
| | - Guoyi Li
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jingkang Guo
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, Shanghai, China
| | - Zhiping Zhang
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, Shanghai, China
| | - Shuzhang Zhang
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, Shanghai, China
| | - Yudan Zhu
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiwei Cheng
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lu Yu
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yonghua Ji
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, Shanghai, China,Xinhua Translational Institute for Cancer Pain, Shanghai, China
| | - Jie Tao
- Department of Neurology and Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China,Putuo Clinical Medical School, Anhui Medical University, Shanghai, China
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