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Renigunta V, Xhaferri N, Shaikh IG, Schlegel J, Bisen R, Sanvido I, Kalpachidou T, Kummer K, Oliver D, Leitner MG, Lindner M. A versatile functional interaction between electrically silent K V subunits and K V7 potassium channels. Cell Mol Life Sci 2024; 81:301. [PMID: 39003683 DOI: 10.1007/s00018-024-05312-1] [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: 03/12/2024] [Revised: 05/23/2024] [Accepted: 06/10/2024] [Indexed: 07/15/2024]
Abstract
Voltage-gated K+ (KV) channels govern K+ ion flux across cell membranes in response to changes in membrane potential. They are formed by the assembly of four subunits, typically from the same family. Electrically silent KV channels (KVS), however, are unable to conduct currents on their own. It has been assumed that these KVS must obligatorily assemble with subunits from the KV2 family into heterotetrameric channels, thereby giving rise to currents distinct from those of homomeric KV2 channels. Herein, we show that KVS subunits indeed also modulate the activity, biophysical properties and surface expression of recombinant KV7 isoforms in a subunit-specific manner. Employing co-immunoprecipitation, and proximity labelling, we unveil the spatial coexistence of KVS and KV7 within a single protein complex. Electrophysiological experiments further indicate functional interaction and probably heterotetramer formation. Finally, single-cell transcriptomic analyses identify native cell types in which this KVS and KV7 interaction may occur. Our findings demonstrate that KV cross-family interaction is much more versatile than previously thought-possibly serving nature to shape potassium conductance to the needs of individual cell types.
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Affiliation(s)
- Vijay Renigunta
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Nermina Xhaferri
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Imran Gousebasha Shaikh
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Jonathan Schlegel
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Rajeshwari Bisen
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Ilaria Sanvido
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Kai Kummer
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Dominik Oliver
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany
| | - Michael G Leitner
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Moritz Lindner
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, 35037, Marburg, Germany.
- The Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
- Department of Ophthalmology, Philipps University Marburg, 35037, Marburg, Germany.
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2
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Hong H, Koo EJ, Park Y, Song G, Joo SY, Kim JA, Gee HY, Jung J, Park K, Han GC, Choie JY, Kim SH. Vestibular hair cells are more prone to damage by excessive acceleration insult in the mouse with KCNQ4 dysfunction. Sci Rep 2024; 14:15260. [PMID: 38956136 PMCID: PMC11219875 DOI: 10.1038/s41598-024-66115-9] [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: 11/17/2023] [Accepted: 06/27/2024] [Indexed: 07/04/2024] Open
Abstract
KCNQ4 is a voltage-gated K+ channel was reported to distribute over the basolateral surface of type 1 vestibular hair cell and/or inner surface of calyx and heminode of the vestibular nerve connected to the type 1 vestibular hair cells of the inner ear. However, the precise localization of KCNQ4 is still controversial and little is known about the vestibular phenotypes caused by KCNQ4 dysfunction or the specific role of KCNQ4 in the vestibular organs. To investigate the role of KCNQ4 in the vestibular organ, 6-g hypergravity stimulation for 24 h, which represents excessive mechanical stimulation of the sensory epithelium, was applied to p.W277S Kcnq4 transgenic mice. KCNQ4 was detected on the inner surface of calyx of the vestibular afferent in transmission electron microscope images with immunogold labelling. Vestibular function decrease was more severe in the Kcnq4p.W277S/p.W277S mice than in the Kcnq4+/+ and Kcnq4+/p.W277S mice after the stimulation. The vestibular function loss was resulted from the loss of type 1 vestibular hair cells, which was possibly caused by increased depolarization duration. Retigabine, a KCNQ activator, prevented hypergravity-induced vestibular dysfunction and hair cell loss. Patients with KCNQ4 mutations also showed abnormal clinical vestibular function tests. These findings suggest that KCNQ4 plays an essential role in calyx and afferent of type 1 vestibular hair cell preserving vestibular function against excessive mechanical stimulation.
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Affiliation(s)
- Hansol Hong
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea
| | - Eun Ji Koo
- Department of Otorhinolaryngology, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Yesai Park
- Department of Otorhinolaryngology, Incheon St. Mary's Hospital, Catholic University College of Medicine, Incheon, Republic of Korea
| | - Gabae Song
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea
| | - Sun Young Joo
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jung Ah Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Heon Yung Gee
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jinsei Jung
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea
| | - Kangyoon Park
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea
| | - Gyu Cheol Han
- Department of Otorhinolaryngology, Gachon University College of Medicine, Incheon, Republic of Korea.
| | - Jae Young Choie
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea.
| | - Sung Huhn Kim
- Department of Otorhinolaryngology, Won-Sang Lee Institute for Hearing Loss, Yonsei University College of Medicine and Graduate School of Medicine, Seoul, Republic of Korea.
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3
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Zhang Y, Xue Y, Ma Y, Du X, Lu B, Wang Y, Yan Z. Improved classification and pathogenicity assessment by comprehensive functional studies in a large data set of KCNQ2 variants. Life Sci 2024; 339:122378. [PMID: 38142737 DOI: 10.1016/j.lfs.2023.122378] [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: 10/08/2023] [Revised: 12/11/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023]
Abstract
AIMS The paucity of functional annotations on hundreds of KCNQ2 variants impedes the diagnosis and treatment of KCNQ2-related disorders. The aims of this work were to determine the functional properties of 331 clinical KCNQ2 variants, interpreted the pathogenicity of 331 variants using functional data,and explored the association between homomeric channel functions and phenotypes. MAIN METHODS We collected 145 KCNQ2 variants from 232 epilepsy patients and 186 KCNQ2 missense variants from the ClinVar database. Whole-cell patch-clamp recording was used to classify the function of 331 variants. Subsequently, we proposed 24 criteria for the pathogenicity interpretation of KCNQ2 variants and used them to assess pathogenicity of 331 variants. Finally, we analyzed the clinical phenotypes of patients carrying these variants, and explored the correlations between functional mechanisms and phenotypes. KEY FINDINGS In the homozygous state, 287 were classified as loss-of-function and 14 as gain-of-function. In the more clinically relative heterozygous state, 200 variants exhibited functional impairment, 121 of which showed dominant-negative effects on wild-type KCNQ2 subunits. After introducing functional data as strong-level evidence to interpret pathogenicity, over half of variants (169/331) were reclassified and 254 were classified as pathogenic/likely pathogenic. Moreover, dominant-negative effect and haploinsufficiency were identified as primary mechanisms in DEE/ID and SeLNE, respectively. The degree of impairment of channel function correlated with the phenotype severity. SIGNIFICANCE Our study reveals the possible cause of KCNQ2-related disorders at the molecular level, provides compelling evidence for clinical classification of KCNQ2 variants, and expands the knowledge of correlations between functional mechanisms and phenotypes.
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Affiliation(s)
- Yuwei Zhang
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China; Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China.
| | - Yuqing Xue
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China; Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China.
| | - Yu Ma
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Xiaonan Du
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China.
| | - Yi Wang
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China.
| | - Zhiqiang Yan
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China; Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China.
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4
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Zhang H, Li H, Lu M, Wang S, Ma X, Wang F, Liu J, Li X, Yang H, Zhang F, Shen H, Buckley NJ, Gamper N, Yamoah EN, Lv P. Repressor element 1-silencing transcription factor deficiency yields profound hearing loss through K v7.4 channel upsurge in auditory neurons and hair cells. eLife 2022; 11:76754. [PMID: 36125121 PMCID: PMC9525063 DOI: 10.7554/elife.76754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Repressor element 1-silencing transcription factor (REST) is a transcriptional repressor that recognizes neuron-restrictive silencer elements in the mammalian genomes in a tissue- and cell-specific manner. The identity of REST target genes and molecular details of how REST regulates them are emerging. We performed conditional null deletion of Rest (cKO), mainly restricted to murine hair cells (HCs) and auditory neurons (aka spiral ganglion neurons [SGNs]). Null inactivation of full-length REST did not affect the development of normal HCs and SGNs but manifested as progressive hearing loss in adult mice. We found that the inactivation of REST resulted in an increased abundance of Kv7.4 channels at the transcript, protein, and functional levels. Specifically, we found that SGNs and HCs from Rest cKO mice displayed increased Kv7.4 expression and augmented Kv7 currents; SGN’s excitability was also significantly reduced. Administration of a compound with Kv7.4 channel activator activity, fasudil, recapitulated progressive hearing loss in mice. In contrast, inhibition of the Kv7 channels by XE991 rescued the auditory phenotype of Rest cKO mice. Previous studies identified some loss-of-function mutations within the Kv7.4-coding gene, Kcnq4, as a causative factor for progressive hearing loss in mice and humans. Thus, the findings reveal that a critical homeostatic Kv7.4 channel level is required for proper auditory functions.
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Affiliation(s)
- Haiwei Zhang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Hongchen Li
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Mingshun Lu
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Shengnan Wang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Xueya Ma
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Fei Wang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Jiaxi Liu
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Xinyu Li
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Haichao Yang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Fan Zhang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Haitao Shen
- Laboratory of Pathology, Hebei Medical University, Hebei, China
| | - Noel J Buckley
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Nikita Gamper
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada Reno, Reno, United States
| | - Ping Lv
- Department of Pharmacology, Hebei Medical University, Hebei, China
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5
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Homma K. The Pathological Mechanisms of Hearing Loss Caused by KCNQ1 and KCNQ4 Variants. Biomedicines 2022; 10:biomedicines10092254. [PMID: 36140355 PMCID: PMC9496569 DOI: 10.3390/biomedicines10092254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/29/2022] Open
Abstract
Deafness-associated genes KCNQ1 (also associated with heart diseases) and KCNQ4 (only associated with hearing loss) encode the homotetrameric voltage-gated potassium ion channels Kv7.1 and Kv7.4, respectively. To date, over 700 KCNQ1 and over 70 KCNQ4 variants have been identified in patients. The vast majority of these variants are inherited dominantly, and their pathogenicity is often explained by dominant-negative inhibition or haploinsufficiency. Our recent study unexpectedly identified cell-death-inducing cytotoxicity in several Kv7.1 and Kv7.4 variants. Elucidation of this cytotoxicity mechanism and identification of its modifiers (drugs) have great potential for aiding the development of a novel pharmacological strategy against many pathogenic KCNQ variants. The purpose of this review is to disseminate this emerging pathological role of Kv7 variants and to underscore the importance of experimentally characterizing disease-associated variants.
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Affiliation(s)
- Kazuaki Homma
- Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; ; Tel.: +1-312-503-5344
- The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60608, USA
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6
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Zheng H, Yan X, Li G, Lin H, Deng S, Zhuang W, Yao F, Lu Y, Xia X, Yuan H, Jin L, Yan Z. Proactive functional classification of all possible missense single-nucleotide variants in KCNQ4. Genome Res 2022; 32:1573-1584. [PMID: 35760561 PMCID: PMC9435748 DOI: 10.1101/gr.276562.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/21/2022] [Indexed: 02/05/2023]
Abstract
Clinical exome sequencing has yielded extensive disease-related missense single-nucleotide variants (SNVs) of uncertain significance, leading to diagnostic uncertainty. KCNQ4 is one of the most commonly responsible genes for autosomal dominant nonsyndromic hearing loss. According to the gnomAD cohort, approximately one in 100 people harbors missense variants in KCNQ4 (missense variants with minor allele frequency > 0.1% were excluded), but most are of unknown consequence. To prospectively characterize the function of all 4085 possible missense SNVs of human KCNQ4, we recorded the whole-cell currents using the patch-clamp technique and categorized 1068 missense SNVs as loss of function, as well as 728 loss-of-function SNVs located in the transmembrane domains. Further, to mimic the heterozygous condition in Deafness nonsyndromic autosomal dominant 2 (DFNA2) patients caused by KCNQ4 variants, we coexpressed loss-of-function variants with wild-type KCNQ4 and found 516 variants showed impaired or only partially rescued heterogeneous channel function. Overall, our functional classification is highly concordant with the auditory phenotypes in Kcnq4 mutant mice and the assessments of pathogenicity in clinical variant interpretations. Taken together, our results provide strong functional evidence to support the pathogenicity classification of newly discovered KCNQ4 missense variants in clinical genetic testing.
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Affiliation(s)
- Honglan Zheng
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Xinhao Yan
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Guanluan Li
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Hengwei Lin
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Siqi Deng
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Wenhui Zhuang
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Fuqiang Yao
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
| | - Yu Lu
- Institute of Rare Diseases, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Xin Xia
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Huijun Yuan
- Institute of Rare Diseases, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Li Jin
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Zhiqiang Yan
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200438, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China
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7
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Frampton DJA, Choudhury K, Nikesjö J, Delemotte L, Liin SI. Subtype-specific responses of hKv7.4 and hKv7.5 channels to polyunsaturated fatty acids reveal an unconventional modulatory site and mechanism. eLife 2022; 11:77672. [PMID: 35642964 PMCID: PMC9159753 DOI: 10.7554/elife.77672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
The KV7.4 and KV7.5 subtypes of voltage-gated potassium channels play a role in important physiological processes such as sound amplification in the cochlea and adjusting vascular smooth muscle tone. Therefore, the mechanisms that regulate KV7.4 and KV7.5 channel function are of interest. Here, we study the effect of polyunsaturated fatty acids (PUFAs) on human KV7.4 and KV7.5 channels expressed in Xenopus oocytes. We report that PUFAs facilitate activation of hKV7.5 by shifting the V50 of the conductance versus voltage (G(V)) curve toward more negative voltages. This response depends on the head group charge, as an uncharged PUFA analogue has no effect and a positively charged PUFA analogue induces positive V50 shifts. In contrast, PUFAs inhibit activation of hKV7.4 by shifting V50 toward more positive voltages. No effect on V50 of hKV7.4 is observed by an uncharged or a positively charged PUFA analogue. Thus, the hKV7.5 channel's response to PUFAs is analogous to the one previously observed in hKV7.1-7.3 channels, whereas the hKV7.4 channel response is opposite, revealing subtype-specific responses to PUFAs. We identify a unique inner PUFA interaction site in the voltage-sensing domain of hKV7.4 underlying the PUFA response, revealing an unconventional mechanism of modulation of hKV7.4 by PUFAs.
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Affiliation(s)
- Damon J A Frampton
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Koushik Choudhury
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Johan Nikesjö
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Lucie Delemotte
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Sara I Liin
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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8
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Cui C, Zhang L, Qian F, Chen Y, Huang B, Wang F, Wang D, Lv J, Wang X, Yan Z, Guo L, Li GL, Shu Y, Liu D, Li H. A humanized murine model, demonstrating dominant progressive hearing loss caused by a novel KCNQ4 mutation (p.G228D) from a large Chinese family. Clin Genet 2022; 102:149-154. [PMID: 35599357 DOI: 10.1111/cge.14164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 11/27/2022]
Abstract
The pathogenic variants in KCNQ4 cause DFNA2 nonsyndromic hearing loss. However, the understanding of genotype-phenotype correlations between KCNQ4 and hearing is limited. Here, we identified a novel KCNQ4 mutation p.G228D from a Chinese family, including heterozygotes characterized by high-frequency hearing loss that is progressive across all frequencies and homozygotes with more severe hearing loss. We constructed a novel murine model with humanized homologous Kcnq4 mutation. The heterozygotes had mid-frequency and high-frequency hearing loss at 4 weeks, and moved toward all frequencies hearing loss at 12 weeks, while the homozygotes had severe-to-profound hearing loss at 8 weeks. The degeneration of outer hair cells (OHCs) was observed from basal to apical turn of cochlea. The reduced K+ currents and depolarized resting potentials were revealed in OHCs. Remarkably, we observed the loss of inner hair cells (IHCs) in the region corresponding to the frequency above 32 kHz at 8-12 weeks. The results suggest the degeneration of OHCs and IHCs may contribute to high-frequency hearing loss in DFNA2 over time. Our findings broaden the variants of KCNQ4 and provide a novel mouse model of progressive hearing loss, which contributes to an understanding of pathogenic mechanism and eventually treatment of DFNA2 progressive hearing loss.
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Affiliation(s)
- Chong Cui
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Luping Zhang
- Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital, Nantong University, Nantong, China
| | - Fuping Qian
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, China
| | - Yuxin Chen
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Bowei Huang
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Fang Wang
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Daqi Wang
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jun Lv
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xuechun Wang
- Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital, Nantong University, Nantong, China
| | - Zhiqiang Yan
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Luo Guo
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China
| | - Geng-Lin Li
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China
| | - Yilai Shu
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Dong Liu
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, China.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Huawei Li
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, China
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9
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Kojima T, Wasano K, Takahashi S, Homma K. Cell death-inducing cytotoxicity in truncated KCNQ4 variants associated with DFNA2 hearing loss. Dis Model Mech 2021; 14:272416. [PMID: 34622280 PMCID: PMC8628632 DOI: 10.1242/dmm.049015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 09/22/2021] [Indexed: 01/30/2023] Open
Abstract
KCNQ4 encodes the homotetrameric voltage-dependent potassium ion channel Kv7.4, and is the causative gene for autosomal dominant nonsyndromic sensorineural hearing loss, DFNA2. Dominant-negative inhibition accounts for the observed dominant inheritance of many DFNA2-associated KCNQ4 variants. In addition, haploinsufficiency has been presumed as the pathological mechanism for truncated Kv7.4 variants lacking the C-terminal tetramerization region, as they are unlikely to exert a dominant-negative inhibitory effect. Such truncated Kv7.4 variants should result in relatively mild hearing loss when heterozygous; however, this is not always the case. In this study, we characterized Kv7.4Q71fs (c.211delC), Kv7.4W242X (c.725G>A) and Kv7.4A349fs (c.1044_1051del8) in heterologous expression systems and found that expression of these truncated Kv7.4 variants induced cell death. We also found similar cell death-inducing cytotoxic effects in truncated Kv7.1 (KCNQ1) variants, suggesting that the generality of our findings could account for the dominant inheritance of many, if not most, truncated Kv7 variants. Moreover, we found that the application of autophagy inducers can ameliorate the cytotoxicity, providing a novel insight for the development of alternative therapeutic strategies for Kv7.4 variants. Summary: Expression of truncated KCNQ4 variants lacking the C-terminal tetramerization domain results in cell-death inducing cytotoxicity, providing novel insight into the development of alternative therapeutic strategies for DFNA2 hearing loss.
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Affiliation(s)
- Takashi Kojima
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.,Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Koichiro Wasano
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.,Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Satoe Takahashi
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Kazuaki Homma
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.,The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60608, USA
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10
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A KCNQ4 c.546C>G Genetic Variant Associated with Late Onset Non-Syndromic Hearing Loss in a Taiwanese Population. Genes (Basel) 2021; 12:genes12111711. [PMID: 34828318 PMCID: PMC8618107 DOI: 10.3390/genes12111711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 11/19/2022] Open
Abstract
Clinical presentation is heterogeneous for autosomal dominant nonsyndromic hearing loss (ADNSHL). Variants of KCNQ4 gene is a common genetic factor of ADNSHL. Few studies have investigated the association between hearing impairment and the variant c.546C>G of KCNQ4. Here, we investigated the phenotype and clinical manifestations of the KCNQ4 variant. Study subjects were selected from the participants of the Taiwan Precision Medicine Initiative. In total, we enrolled 12 individuals with KCNQ4 c.546C>G carriers and 107 non-carriers, and performed pure tone audiometry (PTA) test and phenome-wide association (PheWAS) analysis for the patients. We found that c.546C>G variant was related to an increased risk of hearing loss. All patients with c.546C>G variant were aged >65 years and had sensorineural and high frequency hearing loss. Of these patients, a third (66.7%) showed moderate and progressive hearing loss, 41.7% complained of tinnitus and 16.7% complained of vertigo. Additionally, we found a significant association between KCNQ4 c.546C>G variant, aortic aneurysm, fracture of lower limb and polyneuropathy in diabetes. KCNQ4 c.546C>G is likely a potentially pathogenic variant of ADNSHL in the elderly population. Genetic counseling, annual audiogram and early assistive listening device intervention are highly recommended to prevent profound hearing impairment in this patient group.
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11
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Ledford HA, Park S, Muir D, Woltz RL, Ren L, Nguyen PT, Sirish P, Wang W, Sihn CR, George AL, Knollmann BC, Yamoah EN, Yarov-Yarovoy V, Zhang XD, Chiamvimonvat N. Different arrhythmia-associated calmodulin mutations have distinct effects on cardiac SK channel regulation. J Gen Physiol 2021; 152:211546. [PMID: 33211795 PMCID: PMC7681919 DOI: 10.1085/jgp.202012667] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/25/2020] [Accepted: 10/19/2020] [Indexed: 12/21/2022] Open
Abstract
Calmodulin (CaM) plays a critical role in intracellular signaling and regulation of Ca2+-dependent proteins and ion channels. Mutations in CaM cause life-threatening cardiac arrhythmias. Among the known CaM targets, small-conductance Ca2+-activated K+ (SK) channels are unique, since they are gated solely by beat-to-beat changes in intracellular Ca2+. However, the molecular mechanisms of how CaM mutations may affect the function of SK channels remain incompletely understood. To address the structural and functional effects of these mutations, we introduced prototypical human CaM mutations in human induced pluripotent stem cell–derived cardiomyocyte-like cells (hiPSC-CMs). Using structural modeling and molecular dynamics simulation, we demonstrate that human calmodulinopathy-associated CaM mutations disrupt cardiac SK channel function via distinct mechanisms. CaMD96V and CaMD130G mutants reduce SK currents through a dominant-negative fashion. By contrast, specific mutations replacing phenylalanine with leucine result in conformational changes that affect helix packing in the C-lobe, which disengage the interactions between apo-CaM and the CaM-binding domain of SK channels. Distinct mutant CaMs may result in a significant reduction in the activation of the SK channels, leading to a decrease in the key Ca2+-dependent repolarization currents these channels mediate. The findings in this study may be generalizable to other interactions of mutant CaMs with Ca2+-dependent proteins within cardiac myocytes.
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Affiliation(s)
- Hannah A Ledford
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA
| | - Seojin Park
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, NV
| | - Duncan Muir
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA
| | - Ryan L Woltz
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA
| | - Lu Ren
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA
| | - Phuong T Nguyen
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA
| | - Padmini Sirish
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA
| | - Wenying Wang
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, NV
| | - Choong-Ryoul Sihn
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, NV
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Björn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, School of Medicine, Vanderbilt University, Nashville, TN
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, NV
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA
| | - Xiao-Dong Zhang
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA
| | - Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA
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12
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Zhuang W, Yan Z. The S2-S3 Loop of Kv7.4 Channels Is Essential for Calmodulin Regulation of Channel Activation. Front Physiol 2021; 11:604134. [PMID: 33551832 PMCID: PMC7854705 DOI: 10.3389/fphys.2020.604134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/23/2020] [Indexed: 11/16/2022] Open
Abstract
Kv7.4 (KCNQ4) voltage-gated potassium channels control excitability in the inner ear and the central auditory pathway. Mutations in Kv7.4 channels result in inherited progressive deafness in humans. Calmodulin (CaM) is crucial for regulating Kv7 channels, but how CaM affects Kv7 activity has remained unclear. Here, based on electrophysiological recordings, we report that the third EF hand (EF3) of CaM controls the calcium-dependent regulation of Kv7.4 activation and that the S2–S3 loop of Kv7.4 is essential for the regulation mediated by CaM. Overexpression of the mutant CaM1234, which loses the calcium binding ability of all four EF hands, facilitates Kv7.4 activation by accelerating activation kinetics and shifting the voltage dependence of activation leftwards. The single mutant CaM3, which loses the calcium binding ability of the EF3, phenocopies facilitating effects of CaM1234 on Kv7.4 activation. Kv7.4 channels co-expressed with wild-type (WT) CaM show inhibited activation when intracellular calcium levels increase, while Kv7.4 channels co-expressed with CaM1234 or CaM3 are insensitive to calcium. Mutations C156A, C157A, C158V, R159, and R161A, which are located within the Kv7.4 S2–S3 loop, dramatically facilitate activation of Kv7.4 channels co-expressed with WT CaM but have no effect on activation of Kv7.4 channels co-expressed with CaM3, indicating that these five mutations decrease the inhibitory effect of Ca2+/CaM. The double mutation C156A/R159A decreases Ca2+/CaM binding and completely abolishes CaM-mediated calcium-dependent regulation of Kv7.4 activation. Taken together, our results provide mechanistic insights into CaM regulation of Kv7.4 activation and highlight the crucial role of the Kv7.4 S2–S3 loop in CaM regulation.
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Affiliation(s)
- Wenhui Zhuang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Human Phenome Institute, Fudan University, Shanghai, China
| | - Zhiqiang Yan
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Human Phenome Institute, Fudan University, Shanghai, China.,Shenzhen Bay Laboratory, Institute of Molecular Physiology, Shenzhen, China
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13
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Segin S, Berlin M, Richter C, Medert R, Flockerzi V, Worley P, Freichel M, Camacho Londoño JE. Cardiomyocyte-Specific Deletion of Orai1 Reveals Its Protective Role in Angiotensin-II-Induced Pathological Cardiac Remodeling. Cells 2020; 9:cells9051092. [PMID: 32354146 PMCID: PMC7290784 DOI: 10.3390/cells9051092] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/22/2020] [Accepted: 04/24/2020] [Indexed: 12/11/2022] Open
Abstract
Pathological cardiac remodeling correlates with chronic neurohumoral stimulation and abnormal Ca2+ signaling in cardiomyocytes. Store-operated calcium entry (SOCE) has been described in adult and neonatal murine cardiomyocytes, and Orai1 proteins act as crucial ion-conducting constituents of this calcium entry pathway that can be engaged not only by passive Ca2+ store depletion but also by neurohumoral stimuli such as angiotensin-II. In this study, we, therefore, analyzed the consequences of Orai1 deletion for cardiomyocyte hypertrophy in neonatal and adult cardiomyocytes as well as for other features of pathological cardiac remodeling including cardiac contractile function in vivo. Cellular hypertrophy induced by angiotensin-II in embryonic cardiomyocytes from Orai1-deficient mice was blunted in comparison to cells from litter-matched control mice. Due to lethality of mice with ubiquitous Orai1 deficiency and to selectively analyze the role of Orai1 in adult cardiomyocytes, we generated a cardiomyocyte-specific and temporally inducible Orai1 knockout mouse line (Orai1CM–KO). Analysis of cardiac contractility by pressure-volume loops under basal conditions and of cardiac histology did not reveal differences between Orai1CM–KO mice and controls. Moreover, deletion of Orai1 in cardiomyocytes in adult mice did not protect them from angiotensin-II-induced cardiac remodeling, but cardiomyocyte cross-sectional area and cardiac fibrosis were enhanced. These alterations in the absence of Orai1 go along with blunted angiotensin-II-induced upregulation of the expression of Myoz2 and a lack of rise in angiotensin-II-induced STIM1 and Orai3 expression. In contrast to embryonic cardiomyocytes, where Orai1 contributes to the development of cellular hypertrophy, the results obtained from deletion of Orai1 in the adult myocardium reveal a protective function of Orai1 against the development of angiotensin-II-induced cardiac remodeling, possibly involving signaling via Orai3/STIM1-calcineurin-NFAT related pathways.
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Affiliation(s)
- Sebastian Segin
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Michael Berlin
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Christin Richter
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
| | - Rebekka Medert
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany;
| | - Paul Worley
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA;
| | - Marc Freichel
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Juan E. Camacho Londoño
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany; (S.S.); (M.B.); (C.R.); (R.M.); (M.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
- Correspondence: ; Tel.: +49-6221-54-86863; Fax: +49-6221-54-8644
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14
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Perez-Flores MC, Lee JH, Park S, Zhang XD, Sihn CR, Ledford HA, Wang W, Kim HJ, Timofeyev V, Yarov-Yarovoy V, Chiamvimonvat N, Rabbitt RD, Yamoah EN. Cooperativity of K v7.4 channels confers ultrafast electromechanical sensitivity and emergent properties in cochlear outer hair cells. SCIENCE ADVANCES 2020; 6:eaba1104. [PMID: 32285007 PMCID: PMC7141818 DOI: 10.1126/sciadv.aba1104] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/14/2020] [Indexed: 05/22/2023]
Abstract
The mammalian cochlea relies on active electromotility of outer hair cells (OHCs) to resolve sound frequencies. OHCs use ionic channels and somatic electromotility to achieve the process. It is unclear, though, how the kinetics of voltage-gated ionic channels operate to overcome extrinsic viscous drag on OHCs at high frequency. Here, we report ultrafast electromechanical gating of clustered Kv7.4 in OHCs. Increases in kinetics and sensitivity resulting from cooperativity among clustered-Kv7.4 were revealed, using optogenetics strategies. Upon clustering, the half-activation voltage shifted negative, and the speed of activation increased relative to solitary channels. Clustering also rendered Kv7.4 channels mechanically sensitive, confirmed in consolidated Kv7.4 channels at the base of OHCs. Kv7.4 clusters provide OHCs with ultrafast electromechanical channel gating, varying in magnitude and speed along the cochlea axis. Ultrafast Kv7.4 gating provides OHCs with a feedback mechanism that enables the cochlea to overcome viscous drag and resolve sounds at auditory frequencies.
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Affiliation(s)
- Maria C. Perez-Flores
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Jeong H. Lee
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Seojin Park
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Xiao-Dong Zhang
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Choong-Ryoul Sihn
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Hannah A. Ledford
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
| | - Wenying Wang
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Hyo Jeong Kim
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Valeriy Timofeyev
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Richard D. Rabbitt
- Departments of Biomedical Engineering, Otolaryngology, and Neuroscience Program, University of Utah, Salt Lake City, UT 84112, USA
- Corresponding author. (E.N.Y.); (R.D.R.)
| | - Ebenezer N. Yamoah
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
- Corresponding author. (E.N.Y.); (R.D.R.)
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15
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Molecular basis and restoration of function deficiencies of Kv7.4 variants associated with inherited hearing loss. Hear Res 2020; 388:107884. [PMID: 31995783 DOI: 10.1016/j.heares.2020.107884] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 11/20/2022]
Abstract
Deafness non-syndromic autosomal dominant 2 (DFNA2) is characterized by symmetric, predominantly high-frequency sensorineural hearing loss that is progressive across all frequencies. The disease is associated with variants of a potassium voltage-gated channel subfamily Q member 4 gene, KCNQ4 (Kv7.4). Here, we studied nine recently identified Kv7.4 variants in DFNA2 pedigrees, including V230E, E260K, D262V, Y270H, W275R, G287R, P291L, P291S and S680F. We proved that the variant S680F did not alter the channel function while the other eight variants resulted in function deficiencies. We further proved that the two variants E260K and P291S showed reduced cell membrane expressions while the other seven variants showed moderate cell surface expressions. Thus, trafficking deficiency is not a common mechanism underlying channel dysfunction. Next, we studied two variants, V230E and G287R, using molecular dynamics simulation. We showed that V230E stabilized Kv7.4 channel in the closed state by forming an additional hydrogen bond with a basic residue K325, while G287R distorted the selectivity filter and blocked the pore region of Kv7.4 channel. Moreover, by co-expressing wild-type (WT) and variant proteins in vitro, we demonstrated that the heterogeneous Kv7.4 channel currents were reduced compared to the WT channel currents and the reduction could be rescued by a Kv7.4 opener retigabine. Our study provided the underlying mechanisms and suggested a potential alternative therapeutic approach for DFNA2.
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16
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Jung J, Lin H, Koh YI, Ryu K, Lee JS, Rim JH, Choi HJ, Lee HJ, Kim HY, Yu S, Jin H, Lee JH, Lee MG, Namkung W, Choi JY, Gee HY. Rare KCNQ4 variants found in public databases underlie impaired channel activity that may contribute to hearing impairment. Exp Mol Med 2019; 51:1-12. [PMID: 31434872 PMCID: PMC6802650 DOI: 10.1038/s12276-019-0300-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 04/01/2019] [Accepted: 05/06/2019] [Indexed: 02/08/2023] Open
Abstract
KCNQ4 is frequently mutated in autosomal dominant non-syndromic hearing loss (NSHL), a typically late-onset, initially high-frequency loss that progresses over time (DFNA2). Most KCNQ4 mutations linked to hearing loss are clustered around the pore region of the protein and lead to loss of KCNQ4-mediated potassium currents. To understand the contribution of KCNQ4 variants to NSHL, we surveyed public databases and found 17 loss-of-function and six missense KCNQ4 variants affecting amino acids around the pore region. The missense variants have not been reported as pathogenic and are present at a low frequency (minor allele frequency < 0.0005) in the population. We examined the functional impact of these variants, which, interestingly, induced a reduction in potassium channel activity without altering expression or trafficking of the channel protein, being functionally similar to DFNA2-associated KCNQ4 mutations. Therefore, these variants may be risk factors for late-onset hearing loss, and individuals harboring any one of these variants may develop hearing loss during adulthood. Reduced channel activity could be rescued by KCNQ activators, suggesting the possibility of medical intervention. These findings indicate that KCNQ4 variants may contribute more to late-onset NSHL than expected, and therefore, genetic screening for this gene is important for the prevention and treatment of NSHL.
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Affiliation(s)
- Jinsei Jung
- Department of Otorhinolaryngology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Haiyue Lin
- Department of Otorhinolaryngology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Young Ik Koh
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Kunhi Ryu
- Yonsei University College of Pharmacy, Incheon, 21983, Korea
| | - Joon Suk Lee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - John Hoon Rim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Hye Ji Choi
- Department of Otorhinolaryngology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Hak Joon Lee
- Department of Otorhinolaryngology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Hye-Youn Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Seyoung Yu
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Hyunsoo Jin
- Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Ji Hyun Lee
- Department of Dermatology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 03722, Korea
| | - Min Goo Lee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Wan Namkung
- Yonsei University College of Pharmacy, Incheon, 21983, Korea
| | - Jae Young Choi
- Department of Otorhinolaryngology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea.
| | - Heon Yung Gee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 03722, Korea.
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17
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Wong VSC, Meadows M, Goldberg D, Willis DE. Semaphorin 3A induces acute changes in membrane excitability in spiral ganglion neurons in vitro. Eur J Neurosci 2019; 50:1741-1758. [PMID: 30706560 DOI: 10.1111/ejn.14360] [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: 07/20/2018] [Revised: 01/10/2019] [Accepted: 01/23/2019] [Indexed: 11/29/2022]
Abstract
The development and survival of spiral ganglion neurons (SGNs) are dependent on multiple trophic factors as well as membrane electrical activity. Semaphorins (Sema) constitute a family of membrane-associated and secreted proteins that have garnered significant attention as a potential SGN "navigator" during cochlea development. Previous studies using mutant mice demonstrated that Sema3A plays a role in the SGN pathfinding. The mechanisms, however, by which Sema3A shapes SGNs firing behavior are not known. In these studies, we found that Sema3A plays a novel role in regulating SGN resting membrane potential and excitability. Using dissociated SGN from pre-hearing (P3-P5) and post-hearing mice (P12-P15), we recorded membrane potentials using whole-cell patch clamp recording techniques in apical and basal SGN populations. Recombinant Sema3A was applied to examine the effects on intrinsic membrane properties and action potentials evoked by current injections. Apical and basal SGNs from newborn mice treated with recombinant Sema3A (100 ng/ml) displayed a higher resting membrane potential, higher threshold, decreased amplitude, and prolonged latency and duration of spikes. Although a similar phenomenon was observed in SGNs from post-hearing mice, the resting membrane potential was essentially indistinguishable before and after Sema3A exposure. Sema3A-mediated changes in membrane excitability were associated with a significant decrease in K+ and Ca2+ currents. Sema3A acts through linopirdine-sensitive K+ channels in apical, but not in the basal SGNs. Therefore, Sema3A induces differential effects in SGN membrane excitability that are dependent on age and location, and constitutes an additional early and novel effect of Sema3A SGNs in vitro.
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Affiliation(s)
| | - Marc Meadows
- The Vollum Institute, Oregon Health and Science University, Portland, Oregon
| | - David Goldberg
- The Burke Neurological Institute, White Plains, New York
| | - Dianna E Willis
- The Burke Neurological Institute, White Plains, New York.,Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
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18
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Whole-exome sequencing identifies two novel mutations in KCNQ4 in individuals with nonsyndromic hearing loss. Sci Rep 2018; 8:16659. [PMID: 30413759 PMCID: PMC6226507 DOI: 10.1038/s41598-018-34876-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/27/2018] [Indexed: 11/09/2022] Open
Abstract
Mutations in potassium voltage-gated channel subfamily Q member 4 (KCNQ4) are etiologically linked to a type of nonsyndromic hearing loss, deafness nonsyndromic autosomal dominant 2 (DFNA2). We performed whole-exome sequencing for 98 families with hearing loss and found mutations in KCNQ4 in five families. In this study, we characterized two novel mutations in KCNQ4: a missense mutation (c.796G>T; p.Asp266Tyr) and an in-frame deletion mutation (c.259_267del; p.Val87_Asn89del). p.Asp266Tyr located in the channel pore region resulted in early onset and moderate hearing loss, whereas p.Val87_Asn89del located in the N-terminal cytoplasmic region resulted in late onset and high frequency-specific hearing loss. When heterologously expressed in HEK 293 T cells, both mutant proteins did not show defects in protein trafficking to the plasma membrane or in interactions with wild-type (WT) KCNQ4 channels. Patch-clamp analysis demonstrated that both p.Asp266Tyr and p.Val87_Asn89del mutant channels lost conductance and were completely unresponsive to KCNQ activators, such as retigabine, zinc pyrithione, and ML213. Channels assembled from WT-p.Asp266Tyr concatemers, like those from WT-WT concatemers, exhibited conductance and responsiveness to KCNQ activators. However, channels assembled from WT-p.Val87_Asn89del concatemers showed impaired conductance, suggesting that p.Val87_Asn89del caused complete loss-of-function with a strong dominant-negative effect on functional WT channels. Therefore, the main pathological mechanism may be related to loss of K+ channel activity, not defects in trafficking.
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19
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Pawlak-Osiñska K, Linkowska K, Grzybowski T. Genes important for otoneurological diagnostic purposes - current status and future prospects. ACTA ACUST UNITED AC 2018; 38:242-250. [PMID: 29984802 DOI: 10.14639/0392-100x-1692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/12/2017] [Indexed: 11/23/2022]
Abstract
SUMMARY This review focuses on the current knowledge of the genes responsible for non-syndromic hearing loss that can be useful for otoneurological diagnostic purposes. From among a large number of genes that have been associated with non-syndromic hearing impairment, we selected several best-known genes, including the COCH gene, GJB2, GJB6 and SLC26A4, and we describe their role and effects of mutations and prevalence of mutations in various populations. Next, we focus on genes associated with tinnitus. Important areas for further research include assessment of genes potentially involved in pathophysiology of tinnitus and vertigo, which have traditionally been considered as being of otological aetiology, while advances in neuroimaging techniques have increasingly shifted studies toward neurological correlations.
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Affiliation(s)
- K Pawlak-Osiñska
- Department of Otolaryngology and Oncology Collegium Medicum in Bydgoszcz Nicolaus Copernicus University, Skłodowskiej-Curie 9, Bydgoszcz, Poland
| | - K Linkowska
- Department of Forensic Medicine Division of Molecular and Forensic Genetics Collegium Medicum in Bydgoszcz Nicolaus Copernicus University, Skłodowskiej-Curie 9, Bydgoszcz, Poland
| | - T Grzybowski
- Department of Forensic Medicine Division of Molecular and Forensic Genetics Collegium Medicum in Bydgoszcz Nicolaus Copernicus University, Skłodowskiej-Curie 9, Bydgoszcz, Poland
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20
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Sihn CR, Kim HJ, Woltz RL, Yarov-Yarovoy V, Yang PC, Xu J, Clancy CE, Zhang XD, Chiamvimonvat N, Yamoah EN. Mechanisms of Calmodulin Regulation of Different Isoforms of Kv7.4 K+ Channels. J Biol Chem 2015; 291:2499-509. [PMID: 26515070 DOI: 10.1074/jbc.m115.668236] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Indexed: 01/17/2023] Open
Abstract
Calmodulin (CaM), a Ca(2+)-sensing protein, is constitutively bound to IQ domains of the C termini of human Kv7 (hKv7, KCNQ) channels to mediate Ca(2+)-dependent reduction of Kv7 currents. However, the mechanism remains unclear. We report that CaM binds to two isoforms of the hKv7.4 channel in a Ca(2+)-independent manner but that only the long isoform (hKv7.4a) is regulated by Ca(2+)/CaM. Ca(2+)/CaM mediate reduction of the hKv7.4a channel by decreasing the channel open probability and altering activation kinetics. We took advantage of a known missense mutation (G321S) that has been linked to progressive hearing loss to further examine the inhibitory effects of Ca(2+)/CaM on the Kv7.4 channel. Using multidisciplinary techniques, we demonstrate that the G321S mutation may destabilize CaM binding, leading to a decrease in the inhibitory effects of Ca(2+) on the channels. Our study utilizes an expression system to dissect the biophysical properties of the WT and mutant Kv7.4 channels. This report provides mechanistic insights into the critical roles of Ca(2+)/CaM regulation of the Kv7.4 channel under physiological and pathological conditions.
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Affiliation(s)
- Choong-Ryoul Sihn
- From the Department of Physiology and Cell Biology, Program in Communication Science, School of Medicine, University of Nevada, Reno, Reno, Nevada 85997
| | - Hyo Jeong Kim
- the Department of Internal Medicine, Division of Cardiovascular Medicine
| | - Ryan L Woltz
- the Department of Internal Medicine, Division of Cardiovascular Medicine
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, and the Northern California Health Care System, Department of Veterans Affairs, Mather, California 95655, and
| | - Pei-Chi Yang
- Department of Pharmacology, University of California, Davis, Davis, California 95616
| | - Jun Xu
- the Department of Engineering Technology, College of Science and Technology, Tarleton State University, Stephenville, Texas 76402
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Davis, California 95616
| | - Xiao-Dong Zhang
- the Department of Internal Medicine, Division of Cardiovascular Medicine, the Northern California Health Care System, Department of Veterans Affairs, Mather, California 95655, and
| | - Nipavan Chiamvimonvat
- the Department of Internal Medicine, Division of Cardiovascular Medicine, the Northern California Health Care System, Department of Veterans Affairs, Mather, California 95655, and
| | - Ebenezer N Yamoah
- From the Department of Physiology and Cell Biology, Program in Communication Science, School of Medicine, University of Nevada, Reno, Reno, Nevada 85997,
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21
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Mousavi Nik A, Gharaie S, Jeong Kim H. Cellular mechanisms of mutations in Kv7.1: auditory functions in Jervell and Lange-Nielsen syndrome vs. Romano-Ward syndrome. Front Cell Neurosci 2015; 9:32. [PMID: 25705178 PMCID: PMC4319400 DOI: 10.3389/fncel.2015.00032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 01/19/2015] [Indexed: 01/06/2023] Open
Abstract
As a result of cell-specific functions of voltage-activated K+ channels, such as Kv7.1, mutations in this channel produce profound cardiac and auditory defects. At the same time, the massive diversity of K+ channels allows for compensatory substitution of mutant channels by other functional channels of their type to minimize defective phenotypes. Kv7.1 represents a clear example of such functional dichotomy. While several point mutations in the channel result in a cardio-auditory syndrome called Jervell and Lange-Nielsen syndrome (JLNS), about 100-fold mutations result in long QT syndrome (LQTS) denoted as Romano–Ward syndrome (RWS), which has an intact auditory phenotype. To determine whether the cellular mechanisms for the diverse phenotypic outcome of Kv7.1 mutations, are dependent on the tissue-specific function of the channel and/or specialized functions of the channel, we made series of point mutations in hKv7.1 ascribed to JLNS and RWS. For JLNS mutations, all except W248F yielded non-functional channels when expressed alone. Although W248F at the end of the S4 domain yielded a functional current, it underwent marked inactivation at positive voltages, rendering the channel non-functional. We demonstrate that by definition, none of the JLNS mutants operated in a dominant negative (DN) fashion. Instead, the JLNS mutants have impaired membrane trafficking, trapped in the endoplasmic reticulum (ER) and Cis-Golgi. The RWS mutants exhibited varied functional phenotypes. However, they can be summed up as exhibiting DN effects. Phenotypic differences between JLNS and RWS may stem from tissue-specific functional requirements of cardiac vs. inner ear non-sensory cells.
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Affiliation(s)
- Atefeh Mousavi Nik
- Department of Anesthesiology and Pain Medicine, Center for Neuroscience, School of Medicine, University of California, Davis Davis, CA, USA
| | - Somayeh Gharaie
- Department of Anesthesiology and Pain Medicine, Center for Neuroscience, School of Medicine, University of California, Davis Davis, CA, USA
| | - Hyo Jeong Kim
- Department of Anesthesiology and Pain Medicine, Center for Neuroscience, School of Medicine, University of California, Davis Davis, CA, USA
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22
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Young JC. The role of the cytosolic HSP70 chaperone system in diseases caused by misfolding and aberrant trafficking of ion channels. Dis Model Mech 2015; 7:319-29. [PMID: 24609033 PMCID: PMC3944492 DOI: 10.1242/dmm.014001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Protein-folding diseases are an ongoing medical challenge. Many diseases within this group are genetically determined, and have no known cure. Among the examples in which the underlying cellular and molecular mechanisms are well understood are diseases driven by misfolding of transmembrane proteins that normally function as cell-surface ion channels. Wild-type forms are synthesized and integrated into the endoplasmic reticulum (ER) membrane system and, upon correct folding, are trafficked by the secretory pathway to the cell surface. Misfolded mutant forms traffic poorly, if at all, and are instead degraded by the ER-associated proteasomal degradation (ERAD) system. Molecular chaperones can assist the folding of the cytosolic domains of these transmembrane proteins; however, these chaperones are also involved in selecting misfolded forms for ERAD. Given this dual role of chaperones, diseases caused by the misfolding and aberrant trafficking of ion channels (referred to here as ion-channel-misfolding diseases) can be regarded as a consequence of insufficiency of the pro-folding chaperone activity and/or overefficiency of the chaperone ERAD role. An attractive idea is that manipulation of the chaperones might allow increased folding and trafficking of the mutant proteins, and thereby partial restoration of function. This Review outlines the roles of the cytosolic HSP70 chaperone system in the best-studied paradigms of ion-channel-misfolding disease--the CFTR chloride channel in cystic fibrosis and the hERG potassium channel in cardiac long QT syndrome type 2. In addition, other ion channels implicated in ion-channel-misfolding diseases are discussed.
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Affiliation(s)
- Jason C Young
- McGill University, Department of Biochemistry, Groupe de Recherche Axé sur la Structure des Protéines, 3649 Promenade Sir William Osler, Montreal, QC H3G 0B1, Canada
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23
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Wang H, Zhao Y, Yi Y, Gao Y, Liu Q, Wang D, Li Q, Lan L, Li N, Guan J, Yin Z, Han B, Zhao F, Zong L, Xiong W, Yu L, Song L, Yi X, Yang L, Petit C, Wang Q. Targeted high-throughput sequencing identifies pathogenic mutations in KCNQ4 in two large Chinese families with autosomal dominant hearing loss. PLoS One 2014; 9:e103133. [PMID: 25116015 PMCID: PMC4130520 DOI: 10.1371/journal.pone.0103133] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/27/2014] [Indexed: 11/18/2022] Open
Abstract
Autosomal dominant non-syndromic hearing loss (ADNSHL) is highly heterogeneous, among them, KCNQ4 is one of the most frequent disease-causing genes. More than twenty KCNQ4 mutations have been reported, but none of them were detected in Chinese mainland families. In this study, we identified a novel KCNQ4 mutation in a five generation Chinese family with 84 members and a known KCNQ4 mutation in a six generation Chinese family with 66 members. Mutation screening of 30 genes for ADNSHL was performed in the probands from thirty large Chinese families with ADNSHL by targeted region capture and high-throughput sequencing. The candidate variants and the co-segregation of the phenotype were verified by polymerase chain reaction (PCR) amplification and Sanger sequencing in all ascertained family members. Then we identified a novel KCNQ4 mutation p.W275R in exon 5 and a known KCNQ4 mutation p.G285S in exon 6 in two large Chinese ADNSHL families segregating with post-lingual high frequency-involved and progressive sensorineural hearing loss. This is the first report of KCNQ4 mutation in Chinese mainland families. KCNQ4, a member of voltage-gated potassium channel family, is likely to be a common gene in Chinese patients with ADNSHL. The results also support that the combination of targeted enrichment and high-throughput sequencing is a valuable molecular diagnostic tool for autosomal dominant hereditary deafness.
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Affiliation(s)
- Hongyang Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Yali Zhao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | | | - Yun Gao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Qiong Liu
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Dayong Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Qian Li
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Lan Lan
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Na Li
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Jing Guan
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Zifang Yin
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Bing Han
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Feifan Zhao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Liang Zong
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Wenping Xiong
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Lan Yu
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | | | - Xin Yi
- BGI-Tianjin, Tianjin, China
| | | | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, Paris, France
- UMRS 1120, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
- Université Pierre et Marie Curie (Paris VI), Paris, France
- Collège de France, Paris, France
| | - Qiuju Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
- * E-mail:
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24
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Wang W, Kim HJ, Lee JH, Wong V, Sihn CR, Lv P, Perez Flores MC, Mousavi-Nik A, Doyle KJ, Xu Y, Yamoah EN. Functional significance of K+ channel β-subunit KCNE3 in auditory neurons. J Biol Chem 2014; 289:16802-13. [PMID: 24727472 DOI: 10.1074/jbc.m113.545236] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The KCNE3 β-subunit interacts with and regulates the voltage-dependent gating, kinetics, and pharmacology of a variety of Kv channels in neurons. Because a single neuron may express multiple KCNE3 partners, it is impossible to predict the overall functional relevance of the single transmembrane domain peptide on the pore-forming K(+) channel subunits with which it associates. In the inner ear, the role of KCNE3 is undefined, despite its association with Meniere disease and tinnitus. To gain insights on the functional significance of KCNE3 in auditory neurons, we examined the properties of spiral ganglion neurons (SGNs) in Kcne3 null mutant neurons relative to their age-matched controls. We demonstrate that null deletion of Kcne3 abolishes characteristic wide variations in the resting membrane potentials of SGNs and yields age-dependent alterations in action potential and firing properties of neurons along the contour of the cochlear axis, in comparison with age-matched wild-type neurons. The properties of basal SGNs were markedly altered in Kcne3(-/-) mice compared with the wild-type controls; these include reduced action potential latency, amplitude, and increased firing frequency. Analyses of the underlying conductance demonstrate that null mutation of Kcne3 results in enhanced outward K(+) currents, which is sufficient to explain the ensuing membrane potential changes. Additionally, we have demonstrated that KCNE3 may regulate the activity of Kv4.2 channels in SGNs. Finally, there were developmentally mediated compensatory changes that occurred such that, by 8 weeks after birth, the electrical properties of the null mutant neurons were virtually indistinguishable from the wild-type neurons, suggesting that ion channel remodeling in auditory neurons progresses beyond hearing onset.
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Affiliation(s)
- Wenying Wang
- From the Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang 050017, China, the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Hyo Jeong Kim
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Jeong-Han Lee
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Victor Wong
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Choong-Ryoul Sihn
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Ping Lv
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and the Department of Pharmacology, Hebei Medical University, Shijiazhuang 050017, China
| | - Maria Cristina Perez Flores
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Atefeh Mousavi-Nik
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Karen Jo Doyle
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
| | - Yanfang Xu
- From the Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang 050017, China,
| | - Ebenezer N Yamoah
- the Department of Anesthesiology and Pain Medicine, Program in Communication and Sensory Sciences, University of California at Davis School of Medicine, Davis, California 95618, and
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25
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Wang W, Kim HJ, Lv P, Tempel B, Yamoah EN. Association of the Kv1 family of K+ channels and their functional blueprint in the properties of auditory neurons as revealed by genetic and functional analyses. J Neurophysiol 2013; 110:1751-64. [PMID: 23864368 DOI: 10.1152/jn.00290.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Developmental plasticity in spiral ganglion neurons (SGNs) ensues from profound alterations in the functional properties of the developing hair cell (HC). For example, prehearing HCs are spontaneously active. However, at the posthearing stage, HC membrane properties transition to graded receptor potentials. The dendrotoxin (DTX)-sensitive Kv1 channel subunits (Kv1.1, 1.2, and 1.6) shape the firing properties and membrane potential of SGNs, and the expression of the channel undergoes developmental changes. Because of the stochastic nature of Kv subunit heteromultimerization, it has been difficult to determine physiologically relevant subunit-specific interactions and their functions in the underlying mechanisms of Kv1 channel plasticity in SGNs. Using Kcna2 null mutant mice, we demonstrate a surprising paradox in changes in the membrane properties of SGNs. The resting membrane potential of Kcna2(-/-) SGNs was significantly hyperpolarized compared with that of age-matched wild-type (WT) SGNs. Analyses of outward currents in the mutant SGNs suggest an apparent approximately twofold increase in outward K(+) currents. We show that in vivo and in vitro heteromultimerization of Kv1.2 and Kv1.4 α-subunits underlies the striking and unexpected alterations in the properties of SGNs. The results suggest that heteromeric interactions of Kv1.2 and Kv1.4 dominate the defining features of Kv1 channels in SGNs.
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Affiliation(s)
- Wenying Wang
- Program in Communication Science, Center for Neuroscience, University of California, Davis, School of Medicine, Davis, California
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26
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Gao Y, Yechikov S, Vázquez AE, Chen D, Nie L. Impaired surface expression and conductance of the KCNQ4 channel lead to sensorineural hearing loss. J Cell Mol Med 2013; 17:889-900. [PMID: 23750663 PMCID: PMC3729637 DOI: 10.1111/jcmm.12080] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/29/2013] [Indexed: 01/21/2023] Open
Abstract
KCNQ4, a voltage-gated potassium channel, plays an important role in maintaining cochlear ion homoeostasis and regulating hair cell membrane potential, both essential for normal auditory function. Mutations in the KCNQ4 gene lead to DFNA2, a subtype of autosomal dominant non-syndromic deafness that is characterized by progressive sensorineural hearing loss across all frequencies. Despite recent advances in the identification of pathogenic KCNQ4 mutations, the molecular aetiology of DFNA2 remains unknown. We report here that decreased cell surface expression and impaired conductance of the KCNQ4 channel are two mechanisms underlying hearing loss in DFNA2. In HEK293T cells, a dramatic decrease in cell surface expression was detected by immunofluorescent microscopy and confirmed by Western blot for the pathogenic KCNQ4 mutants L274H, W276S, L281S, G285C, G285S, G296S and G321S, while their overall cellular levels remained normal. In addition, none of these mutations affected tetrameric assembly of KCNQ4 channels. Consistent with these results, all mutants showed strong dominant-negative effects on the wild-type (WT) channel function. Most importantly, overexpression of HSP90β, a key component of the molecular chaperone network that controls the KCNQ4 biogenesis, significantly increased cell surface expression of the KCNQ4 mutants L281S, G296S and G321S. KCNQ4 surface expression was restored or considerably improved in HEK293T cells mimicking the heterozygous condition of these mutations in DFNA2 patients. Finally, our electrophysiological studies demonstrated that these mutations directly compromise the conductance of the KCNQ4 channel, since no significant change in KCNQ4 current was observed after KCNQ4 surface expression was restored or improved.
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Affiliation(s)
- Yanhong Gao
- Department of Otolaryngology, University of California Davis, Davis, CA, USA
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27
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Gao Y, Yechikov S, Vazquez AE, Chen D, Nie L. Distinct roles of molecular chaperones HSP90α and HSP90β in the biogenesis of KCNQ4 channels. PLoS One 2013; 8:e57282. [PMID: 23431407 PMCID: PMC3576372 DOI: 10.1371/journal.pone.0057282] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 01/21/2013] [Indexed: 01/30/2023] Open
Abstract
Loss-of-function mutations in the KCNQ4 channel cause DFNA2, a subtype of autosomal dominant non-syndromic deafness that is characterized by progressive sensorineural hearing loss. Previous studies have demonstrated that the majority of the pathogenic KCNQ4 mutations lead to trafficking deficiency and loss of KCNQ4 currents. Over the last two decades, various strategies have been developed to rescue trafficking deficiency of pathogenic mutants; the most exciting advances have been made by manipulating activities of molecular chaperones involved in the biogenesis and quality control of the target protein. However, such strategies have not been established for KCNQ4 mutants and little is known about the molecular chaperones governing the KCNQ4 biogenesis. To identify KCNQ4-associated molecular chaperones, a proteomic approach was used in this study. As a result, two major molecular chaperones, HSP70 and HSP90, were identified and then confirmed by reciprocal co-immunoprecipitation assays, suggesting that the HSP90 chaperone pathway might be involved in the KCNQ4 biogenesis. Manipulating chaperone expression further revealed that two different isoforms of HSP90, the inducible HSP90α and the constitutive HSP90β, had opposite effects on the cellular level of the KCNQ4 channel; that HSP40, HSP70, and HOP, three key components of the HSP90 chaperone pathway, were crucial in facilitating KCNQ4 biogenesis. In contrast, CHIP, a major E3 ubiquitin ligase, had an opposite effect. Collectively, our data suggest that HSP90α and HSP90β play key roles in controlling KCNQ4 homeostasis via the HSP40-HSP70-HOP-HSP90 chaperone pathway and the ubiquitin-proteasome pathway. Most importantly, we found that over-expression of HSP90β significantly improved cell surface expression of the trafficking-deficient, pathogenic KCNQ4 mutants L274H and W276S. KCNQ4 surface expression was restored by HSP90β in cells mimicking heterozygous conditions of the DFNA2 patients, even though it was not sufficient to rescue the function of KCNQ4 channels.
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Affiliation(s)
- Yanhong Gao
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Sergey Yechikov
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Ana E. Vazquez
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
- * E-mail: (AEV); (LN)
| | - Dongyang Chen
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Liping Nie
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
- * E-mail: (AEV); (LN)
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28
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Spitzmaul G, Tolosa L, Winkelman BHJ, Heidenreich M, Frens MA, Chabbert C, de Zeeuw CI, Jentsch TJ. Vestibular role of KCNQ4 and KCNQ5 K+ channels revealed by mouse models. J Biol Chem 2013; 288:9334-44. [PMID: 23408425 DOI: 10.1074/jbc.m112.433383] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The function of sensory hair cells of the cochlea and vestibular organs depends on an influx of K(+) through apical mechanosensitive ion channels and its subsequent removal over their basolateral membrane. The KCNQ4 (Kv7.4) K(+) channel, which is mutated in DFNA2 human hearing loss, is expressed in the basal membrane of cochlear outer hair cells where it may mediate K(+) efflux. Like the related K(+) channel KCNQ5 (Kv7.5), KCNQ4 is also found at calyx terminals ensheathing type I vestibular hair cells where it may be localized pre- or postsynaptically. Making use of Kcnq4(-/-) mice lacking KCNQ4, as well as Kcnq4(dn/dn) and Kcnq5(dn/dn) mice expressing dominant negative channel mutants, we now show unambiguously that in adult mice both channels reside in postsynaptic calyx-forming neurons, but cannot be detected in the innervated hair cells. Accordingly, whole cell currents of vestibular hair cells did not differ between genotypes. Neither Kcnq4(-/-), Kcnq5(dn/dn) nor Kcnq4(-/-)/Kcnq5(dn/dn) double mutant mice displayed circling behavior found with severe vestibular impairment. However, a milder form of vestibular dysfunction was apparent from altered vestibulo-ocular reflexes in Kcnq4(-/-)/Kcnq5(dn/dn) and Kcnq4(-/-) mice. The larger impact of KCNQ4 may result from its preferential expression in central zones of maculae and cristae, which are innervated by phasic neurons that are more sensitive than the tonic neurons present predominantly in the surrounding peripheral zones where KCNQ5 is found. The impact of postsynaptic KCNQ4 on vestibular function may be related to K(+) removal and modulation of synaptic transmission.
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Affiliation(s)
- Guillermo Spitzmaul
- Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13125 Berlin, Germany
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Watabe T, Matsunaga T, Namba K, Mutai H, Inoue Y, Ogawa K. Moderate hearing loss associated with a novel KCNQ4 non-truncating mutation located near the N-terminus of the pore helix. Biochem Biophys Res Commun 2013; 432:475-9. [PMID: 23399560 DOI: 10.1016/j.bbrc.2013.01.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 10/27/2022]
Abstract
Genetic mutation is one of the causative factors for idiopathic progressive hearing loss. A patient with late-onset, moderate, and high-frequency hearing loss was found to have a novel, heterozygous KCNQ4 mutation, c.806_808delCCT, which led to a p.Ser260del located between S5 and the pore helix (PH). Molecular modeling analysis suggested that the p.Ser269del mutation could cause structural distortion and change in the electrostatic surface potential of the KCNQ4 channel protein, which may impede K+ transport. The present study supports the idea that a non-truncating mutation around the N-terminus of PH may be related to moderate hearing loss.
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Affiliation(s)
- Takahisa Watabe
- Department of Otolaryngology, Head and Neck Surgery, Keio University, School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
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Leitner MG, Feuer A, Ebers O, Schreiber DN, Halaszovich CR, Oliver D. Restoration of ion channel function in deafness-causing KCNQ4 mutants by synthetic channel openers. Br J Pharmacol 2012; 165:2244-59. [PMID: 21951272 DOI: 10.1111/j.1476-5381.2011.01697.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE DFNA2 is a frequent hereditary hearing disorder caused by loss-of-function mutations in the voltage-gated potassium channel KCNQ4 (Kv7.4). KCNQ4 mediates the predominant K(+) conductance, I(K,n) , of auditory outer hair cells (OHCs), and loss of KCNQ4 function leads to degeneration of OHCs resulting in progressive hearing loss. Here we explore the possible recovery of channel activity of mutant KCNQ4 induced by synthetic KCNQ channel openers. EXPERIMENTAL APPROACH Whole cell patch clamp recordings were performed on CHO cells transiently expressing KCNQ4 wild-type (wt) and DFNA2-relevant mutants, and from acutely isolated OHCs. KEY RESULTS Various known KCNQ channel openers robustly enhanced KCNQ4 currents. The strongest potentiation was observed with a combination of zinc pyrithione plus retigabine. A similar albeit less pronounced current enhancement was observed with native I(K,n) currents in rat OHCs. DFNA2 mutations located in the channel's pore region abolished channel function and these mutant channels were completely unresponsive to channel openers. However, the function of a DFNA2 mutation located in the proximal C-terminus was restored by the combined application of both openers. Co-expression of wt and KCNQ4 pore mutants suppressed currents to barely detectable levels. In this dominant-negative situation, channel openers essentially restored currents back to wt levels, most probably through strong activation of only the small fraction of homomeric wt channels. CONCLUSIONS AND IMPLICATIONS Our data suggest that by stabilizing the KCNQ4-mediated conductance in OHCs, chemical channel openers can protect against OHC degeneration and progression of hearing loss in DFNA2.
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Affiliation(s)
- Michael G Leitner
- Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
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Namba K, Mutai H, Kaneko H, Hashimoto S, Matsunaga T. In silico modeling of the pore region of a KCNQ4 missense mutant from a patient with hearing loss. BMC Res Notes 2012; 5:145. [PMID: 22420747 PMCID: PMC3374714 DOI: 10.1186/1756-0500-5-145] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/15/2012] [Indexed: 11/16/2022] Open
Abstract
Background Mutation of the voltage-gated potassium channel KCNQ4 causes DFNA2-type nonsyndromic autosomal dominant sensorineural hearing loss. KCNQ4 is expressed predominantly in the auditory sensory outer hair cells, which are critical for sound amplification. Results We sequenced KCNQ4 from Japanese patients with sensorineural hearing loss, and identified a novel missense mutation encoding a Tyr270His located at the N-terminus of the highly conserved pore helix sequence. As this patient was not accessible to us and information about them was limited, we used molecular modeling to investigate whether this novel mutation is hypothetically pathogenic. A careful examination of an in silico structural model of the KCNQ4 pore region revealed that the Tyr270His mutation caused an alteration in the electrostatic surface potential of the pore helix. Conclusion We propose two possible means by which the Tyr270His mutation causes hearing loss: a positively charged His270 side chain might enhance the helix dipole moment of the pore helix, thereby destabilizing the helix and/or the pore region, or it might disturb transport of K+ through the channel by electrostatic repulsion.
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Affiliation(s)
- Kazunori Namba
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan
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32
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Tune in to KCNQ. Nat Neurosci 2011; 15:8-10. [PMID: 22193251 DOI: 10.1038/nn.3012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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KCNQ4 K+ channels tune mechanoreceptors for normal touch sensation in mouse and man. Nat Neurosci 2011; 15:138-45. [DOI: 10.1038/nn.2985] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 10/11/2011] [Indexed: 12/11/2022]
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