1
|
Moura J, Oliveira J, Santos M, Costa S, Silva L, Lemos C, Barros J, Sequeiros J, Damásio J. Spinocerebellar Ataxias: Phenotypic Spectrum of PolyQ versus Non-Repeat Expansion Forms. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01723-9. [PMID: 39048885 DOI: 10.1007/s12311-024-01723-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2024] [Indexed: 07/27/2024]
Abstract
Spinocerebellar ataxias (SCA) are most frequently due to (CAG)n (coding for polyglutamine, polyQ) expansions and, less so, to expansion of other oligonucleotide repeats (non-polyQ) or other type of variants (non-repeat expansion SCA). In this study we compared polyQ and non-repeat expansion SCA, in a cohort of patients with hereditary ataxia followed at a tertiary hospital. From a prospective study, 88 patients (51 families) with SCA were selected, 74 (40 families) of whom genetically diagnosed. Thirty-eight patients (51.4%, 19 families) were confirmed as having a polyQ (no other repeat-expansions were identified) and 36 (48.6%, 21 families) a non-repeat expansion SCA. Median age-at-onset was 39.5 [30.0-45.5] for polyQ and 7.0 years [1.00-21.50] for non-repeat expansion SCA. PolyQ SCA were associated with cerebellar onset, and non-repeat expansion forms with non-cerebellar onset. Time to diagnosis was longer for non-repeat expansion SCA. The most common polyQ SCA were Machado-Joseph disease (MJD/SCA3) (73.7%) and SCA2 (15.8%); whereas in non-repeat expansion SCA ATX-CACNA1A (14.3%), ATP1A3-related ataxia, ATX-ITPR1, ATX/HSP-KCNA2, and ATX-PRKCG (9.5% each) predominated. Disease duration (up to inclusion) was significantly higher in non-repeat expansion SCA, but the difference in SARA score was not statistically significant. Cerebellar peduncles and pons atrophy were more common in polyQ ataxias, as was axonal neuropathy. SCA had a wide range of genetic etiology, age-at-onset and presentation. Proportion of polyQ and non-repeat expansion SCA was similar; the latter had a higher genetic heterogeneity. While polyQ ataxias were typically linked to cerebellar onset in adulthood, non-repeat expansion forms associated with early onset and non-cerebellar presentations.
Collapse
Affiliation(s)
- João Moura
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Jorge Oliveira
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Mariana Santos
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sara Costa
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Lénia Silva
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Carolina Lemos
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - José Barros
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - Jorge Sequeiros
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - Joana Damásio
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal.
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal.
| |
Collapse
|
2
|
Guo XB, Deng X, Wang J, Qi Y, Zhao W, Guan S. HAX-1 interferes in assembly of NLRP3-ASC to block microglial pyroptosis in cerebral I/R injury. Cell Death Discov 2024; 10:264. [PMID: 38811533 PMCID: PMC11136987 DOI: 10.1038/s41420-024-02005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/31/2024] Open
Abstract
Acute cerebral ischemia has a high rate of disability and death. Although timely recanalization therapy may rescue the ischemic brain tissue, cerebral ischemia-reperfusion injury has been shown to limit the therapeutic effects of vascular recanalization. Protein HAX-1 has been reported as a pro-survival protein that plays an important role in various disorders, particularly in association with the nervous system. However, the effects and mechanisms of HAX-1 in cerebral IR injury have yet to be elucidated. So, we aimed to investigate the effect of HAX-1 on microglial pyroptosis and explore its potential neuroprotective effects in ischemia-reperfusion injury. Our results show that the expression of HAX-1 decreased after cerebral IR injury, accompanied by an increase in pyroptosis pathway activation. In addition, HAX-1 could inhibit microglial pyroptosis both in vivo and in vitro and reduce the release of inflammatory mediators. The above neuroprotective effects might be partially mediated by inhibiting of interaction of NLRP3 and ASC through competitive binding, followed by the attenuation of NLRP3 inflammasome formation. In conclusion, Our findings support that HAX-1 exhibits a protective role in cerebral I/R injury, and further study on HAX-1 expression regulation will contribute to cerebral infarction therapy.
Collapse
Affiliation(s)
- Xin-Bin Guo
- Department of Neuro-interventional Radiology, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe Road, 450052, Zhengzhou, China
| | - Xin Deng
- Department of Neuro-interventional Radiology, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe Road, 450052, Zhengzhou, China
| | - Jingjing Wang
- Department of Neuro-interventional Radiology, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe Road, 450052, Zhengzhou, China
| | - Yuruo Qi
- Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, School of Pharmaceutical Sciences, Zhengzhou University, 100 Kexue Avenue, 450001, Zhengzhou, Henan, China
| | - Wen Zhao
- Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, School of Pharmaceutical Sciences, Zhengzhou University, 100 Kexue Avenue, 450001, Zhengzhou, Henan, China.
| | - Sheng Guan
- Department of Neuro-interventional Radiology, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe Road, 450052, Zhengzhou, China.
| |
Collapse
|
3
|
Gazulla J, Berciano J. Potential Benefit of Channel Activators in Loss-of-Function Primary Potassium Channelopathies Causing Heredoataxia. CEREBELLUM (LONDON, ENGLAND) 2024; 23:833-837. [PMID: 37460907 DOI: 10.1007/s12311-023-01584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/29/2023] [Indexed: 03/20/2024]
Abstract
Potassium channels (KCN) are transmembrane complexes that regulate the resting membrane potential and the duration of action potentials in cells. The opening of KCN brings about an efflux of K+ ions that induces cell repolarization after depolarization, returns the transmembrane potential to its resting state, and enables for continuous spiking ability. The aim of this work was to assess the role of KCN dysfunction in the pathogenesis of hereditary ataxias and the mechanisms of action of KCN opening agents (KCO). In consequence, a review of the ad hoc medical literature was performed. Among hereditary KCN diseases causing ataxia, mutated Kv3.3, Kv4.3, and Kv1.1 channels provoke spinocerebellar ataxia (SCA) type 13, SCA19/22, and episodic ataxia type 1 (EA1), respectively. The K+ efflux was found to be reduced in experimental models of these diseases, resulting in abnormally prolonged depolarization and incomplete repolarization, thereby interfering with repetitive discharges in the cells. Hence, substances able to promote normal spiking activity in the cerebellum could provide symptomatic benefit. Although drugs used in clinical practice do not activate Kv3.3 or Kv4.3 directly, available KCO probably could ameliorate ataxic symptoms in SCA13 and SCA19/22, as verified with acetazolamide in EA1, and retigabine in a mouse model of hypokalemic periodic paralysis. To summarize, ataxia could possibly be improved by non-specific KCO in SCA13 and SCA19/22. The identification of new specific KCO agents will undoubtedly constitute a promising therapeutic strategy for these diseases.
Collapse
Affiliation(s)
- José Gazulla
- Department of Neurology, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Saragossa, Spain.
| | - José Berciano
- Department of Neurology, Hospital Universitario Marqués de Valdecilla (IDIVAL), University of Cantabria, CIBERNED, Avenida de Valdecilla S/N, 39008, Santander, Spain
| |
Collapse
|
4
|
Woolley PR, Wen X, Conway OM, Ender NA, Lee JH, Paull TT. Regulation of transcription patterns, poly(ADP-ribose), and RNA-DNA hybrids by the ATM protein kinase. Cell Rep 2024; 43:113896. [PMID: 38442018 PMCID: PMC11022685 DOI: 10.1016/j.celrep.2024.113896] [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: 06/01/2023] [Revised: 01/11/2024] [Accepted: 02/15/2024] [Indexed: 03/07/2024] Open
Abstract
The ataxia telangiectasia mutated (ATM) protein kinase is a master regulator of the DNA damage response and also an important sensor of oxidative stress. Analysis of gene expression in ataxia-telangiectasia (A-T) patient brain tissue shows that large-scale transcriptional changes occur in patient cerebellum that correlate with the expression level and guanine-cytosine (GC) content of transcribed genes. In human neuron-like cells in culture, we map locations of poly(ADP-ribose) and RNA-DNA hybrid accumulation genome-wide with ATM inhibition and find that these marks also coincide with high transcription levels, active transcription histone marks, and high GC content. Antioxidant treatment reverses the accumulation of R-loops in transcribed regions, consistent with the central role of reactive oxygen species in promoting these lesions. Based on these results, we postulate that transcription-associated lesions accumulate in ATM-deficient cells and that the single-strand breaks and PARylation at these sites ultimately generate changes in transcription that compromise cerebellum function and lead to neurodegeneration over time in A-T patients.
Collapse
Affiliation(s)
- Phillip R Woolley
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Xuemei Wen
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Olivia M Conway
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Nicolette A Ender
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Ji-Hoon Lee
- Department of Biological Sciences, Research Center of Ecomimetics, Chonnam National University, Gwangju 61186, Republic of Korea.
| | - Tanya T Paull
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA.
| |
Collapse
|
5
|
Woolley PR, Wen X, Conway OM, Ender NA, Lee JH, Paull TT. Regulation of transcription patterns, poly-ADP-ribose, and RNA-DNA hybrids by the ATM protein kinase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570417. [PMID: 38106035 PMCID: PMC10723464 DOI: 10.1101/2023.12.06.570417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The ATM protein kinase is a master regulator of the DNA damage response and also an important sensor of oxidative stress. Analysis of gene expression in Ataxia-telangiectasia patient brain tissue shows that large-scale transcriptional changes occur in patient cerebellum that correlate with expression level and GC content of transcribed genes. In human neuron-like cells in culture we map locations of poly-ADP-ribose and RNA-DNA hybrid accumulation genome-wide with ATM inhibition and find that these marks also coincide with high transcription levels, active transcription histone marks, and high GC content. Antioxidant treatment reverses the accumulation of R-loops in transcribed regions, consistent with the central role of ROS in promoting these lesions. Based on these results we postulate that transcription-associated lesions accumulate in ATM-deficient cells and that the single-strand breaks and PARylation at these sites ultimately generate changes in transcription that compromise cerebellum function and lead to neurodegeneration over time in A-T patients.
Collapse
Affiliation(s)
- Phillip R. Woolley
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712
| | - Xuemei Wen
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712
| | - Olivia M. Conway
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712
| | - Nicolette A. Ender
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712
| | - Ji-Hoon Lee
- Department of Biological Sciences, Research Center of Ecomimetics, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Tanya T. Paull
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712
| |
Collapse
|
6
|
Li S, Shang D, Du Y, Li Y, Liu R. Epilepsy as the symptom of a spinocerebellar ataxia 13 in a patient presenting with a mutation in the KCNC3 gene. BMC Neurol 2023; 23:246. [PMID: 37365508 DOI: 10.1186/s12883-023-03304-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023] Open
Abstract
BACKGROUND The spinocerebellar ataxias (SCAs) refer to a diverse group of neurodegenerative illnesses that vary clinically and genetically. One of the rare subtypes within this group is SCA13, caused by mutations in the KCNC3 gene. Currently, the prevalence of SCA13 remains uncertain, with only a couple of cases being documented in the Chinese population. This study presented a case study of SCA13, where the patient exhibited clinical symptoms of epilepsy and ataxia. The confirmation of the diagnosis was done through Whole Exome Sequncing. CASE PRESENTATION Since childhood, the seventeen-year-old patient has not been capable of participating in numerous sporting activities and has experienced multiple episodes of unconsciousness within the last two years. The neurological evaluation showed a lack of coordination in the lower limbs. Cerebellar atrophy was detected through brain magnetic resonance imaging (MRI). The patient's gene detection results showed that they exhibit a heterozygous c.1268G > A mutation in the KCNC3 gene located at chr19:50826942. Antiepileptic treatment was promptly administered to the patient, and as a result, her epileptic seizures were resolved quickly. She has since remained free of seizures. After a one-year follow-up, there was no apparent improvement in the patient's health status except seizure free, which may have worsened. CONCLUSION The case study highlights the importance of actively combining cranial MRI with genetic detection in patients with ataxia of no known cause, particularly in children and young patients, to establish an possibly obvious detection. Patients who are young and have ataxia that is first accompanied by extrapyramidal and epilepsy syndromes should be aware of the potential of having SCA13.
Collapse
Affiliation(s)
- Shao Li
- Department of Neurology, Luoyang Central Hospital Affiliated to Zhengzhou University, NO. 288, Middle Zhongzhou Road, Xigong Square, Luoyang, 471000, China.
| | - Dandan Shang
- Department of Neurology, Luoyang Central Hospital Affiliated to Zhengzhou University, NO. 288, Middle Zhongzhou Road, Xigong Square, Luoyang, 471000, China
| | - Yanjiao Du
- Department of Neurology, Luoyang Central Hospital Affiliated to Zhengzhou University, NO. 288, Middle Zhongzhou Road, Xigong Square, Luoyang, 471000, China
| | - Yan Li
- Department of Neurology, Luoyang Central Hospital Affiliated to Zhengzhou University, NO. 288, Middle Zhongzhou Road, Xigong Square, Luoyang, 471000, China
| | - Ruihua Liu
- Department of Neurology, Luoyang Central Hospital Affiliated to Zhengzhou University, NO. 288, Middle Zhongzhou Road, Xigong Square, Luoyang, 471000, China
| |
Collapse
|
7
|
Kapfhammer JP, Shimobayashi E. Viewpoint: spinocerebellar ataxias as diseases of Purkinje cell dysfunction rather than Purkinje cell loss. Front Mol Neurosci 2023; 16:1182431. [PMID: 37426070 PMCID: PMC10323145 DOI: 10.3389/fnmol.2023.1182431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/22/2023] [Indexed: 07/11/2023] Open
Abstract
Spinocerebellar ataxias (SCAs) are a group of hereditary neurodegenerative diseases mostly affecting cerebellar Purkinje cells caused by a wide variety of different mutations. One subtype, SCA14, is caused by mutations of Protein Kinase C gamma (PKCγ), the dominant PKC isoform present in Purkinje cells. Mutations in the pathway in which PKCγ is active, i.e., in the regulation of calcium levels and calcium signaling in Purkinje cells, are the cause of several other variants of SCA. In SCA14, many of the observed mutations in the PKCγ gene were shown to increase the basal activity of PKCγ, raising the possibility that increased activity of PKCγ might be the cause of most forms of SCA14 and might also be involved in the pathogenesis of SCA in related subtypes. In this viewpoint and review article we will discuss the evidence for and against such a major role of PKCγ basal activity and will suggest a hypothesis of how PKCγ activity and the calcium signaling pathway may be involved in the pathogenesis of SCAs despite the different and sometimes opposing effects of mutations affecting these pathways. We will then widen the scope and propose a concept of SCA pathogenesis which is not primarily driven by cell death and loss of Purkinje cells but rather by dysfunction of Purkinje cells which are still present and alive in the cerebellum.
Collapse
|
8
|
Huang H, Shakkottai VG. Targeting Ion Channels and Purkinje Neuron Intrinsic Membrane Excitability as a Therapeutic Strategy for Cerebellar Ataxia. Life (Basel) 2023; 13:1350. [PMID: 37374132 DOI: 10.3390/life13061350] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/03/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
In degenerative neurological disorders such as Parkinson's disease, a convergence of widely varying insults results in a loss of dopaminergic neurons and, thus, the motor symptoms of the disease. Dopamine replacement therapy with agents such as levodopa is a mainstay of therapy. Cerebellar ataxias, a heterogeneous group of currently untreatable conditions, have not been identified to have a shared physiology that is a target of therapy. In this review, we propose that perturbations in cerebellar Purkinje neuron intrinsic membrane excitability, a result of ion channel dysregulation, is a common pathophysiologic mechanism that drives motor impairment and vulnerability to degeneration in cerebellar ataxias of widely differing genetic etiologies. We further propose that treatments aimed at restoring Purkinje neuron intrinsic membrane excitability have the potential to be a shared therapy in cerebellar ataxia akin to levodopa for Parkinson's disease.
Collapse
Affiliation(s)
- Haoran Huang
- Medical Scientist Training Program, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Vikram G Shakkottai
- Department of Neurology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
9
|
Nitta Y, Sugie A. Studies of neurodegenerative diseases using Drosophila and the development of novel approaches for their analysis. Fly (Austin) 2022; 16:275-298. [PMID: 35765969 PMCID: PMC9336468 DOI: 10.1080/19336934.2022.2087484] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The use of Drosophila in neurodegenerative disease research has contributed to the identification of modifier genes for the pathology. The basis for neurodegenerative disease occurrence in Drosophila is the conservation of genes across species and the ability to perform rapid genetic analysis using a compact brain. Genetic findings previously discovered in Drosophila can reveal molecular pathologies involved in human neurological diseases in later years. Disease models using Drosophila began to be generated during the development of genetic engineering. In recent years, results of reverse translational research using Drosophila have been reported. In this review, we discuss research on neurodegenerative diseases; moreover, we introduce various methods for quantifying neurodegeneration in Drosophila.
Collapse
Affiliation(s)
- Yohei Nitta
- Brain Research Institute, Niigata University, Niigata, Japan
| | - Atsushi Sugie
- Brain Research Institute, Niigata University, Niigata, Japan,CONTACT Atsushi Sugie Brain Research Institute, Niigata University, Niigata, Japan
| |
Collapse
|
10
|
Kolesnikova TO, Demin KA, Costa FV, Zabegalov KN, de Abreu MS, Gerasimova EV, Kalueff AV. Towards Zebrafish Models of CNS Channelopathies. Int J Mol Sci 2022; 23:ijms232213979. [PMID: 36430455 PMCID: PMC9693542 DOI: 10.3390/ijms232213979] [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: 09/14/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Channelopathies are a large group of systemic disorders whose pathogenesis is associated with dysfunctional ion channels. Aberrant transmembrane transport of K+, Na+, Ca2+ and Cl- by these channels in the brain induces central nervous system (CNS) channelopathies, most commonly including epilepsy, but also migraine, as well as various movement and psychiatric disorders. Animal models are a useful tool for studying pathogenesis of a wide range of brain disorders, including channelopathies. Complementing multiple well-established rodent models, the zebrafish (Danio rerio) has become a popular translational model organism for neurobiology, psychopharmacology and toxicology research, and for probing mechanisms underlying CNS pathogenesis. Here, we discuss current prospects and challenges of developing genetic, pharmacological and other experimental models of major CNS channelopathies based on zebrafish.
Collapse
Affiliation(s)
| | - Konstantin A. Demin
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
| | - Fabiano V. Costa
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | | | - Murilo S. de Abreu
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| | - Elena V. Gerasimova
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | - Allan V. Kalueff
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, 197758 St. Petersburg, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
- Scientific Research Institute of Neurosciences and Medicine, 630117 Novosibirsk, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| |
Collapse
|
11
|
Mukherjee S, Cassini TA, Hu N, Yang T, Li B, Shen W, Moth CW, Rinker DC, Sheehan JH, Cogan JD, Newman JH, Hamid R, Macdonald RL, Roden DM, Meiler J, Kuenze G, Phillips JA, Capra JA. Personalized structural biology reveals the molecular mechanisms underlying heterogeneous epileptic phenotypes caused by de novo KCNC2 variants. HGG ADVANCES 2022; 3:100131. [PMID: 36035247 PMCID: PMC9399384 DOI: 10.1016/j.xhgg.2022.100131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/11/2022] [Indexed: 11/28/2022] Open
Abstract
Whole-exome sequencing (WES) in the clinic has identified several rare monogenic developmental and epileptic encephalopathies (DEE) caused by ion channel variants. However, WES often fails to provide actionable insight for rare diseases, such as DEEs, due to the challenges of interpreting variants of unknown significance (VUS). Here, we describe a "personalized structural biology" (PSB) approach that leverages recent innovations in the analysis of protein 3D structures to address this challenge. We illustrate this approach in an Undiagnosed Diseases Network (UDN) individual with DEE symptoms and a de novo VUS in KCNC2 (p.V469L), the Kv3.2 voltage-gated potassium channel. A nearby KCNC2 variant (p.V471L) was recently suggested to cause DEE-like phenotypes. Computational structural modeling suggests that both affect protein function. However, despite their proximity, the p.V469L variant is likely to sterically block the channel pore, while the p.V471L variant is likely to stabilize the open state. Biochemical and electrophysiological analyses demonstrate heterogeneous loss-of-function and gain-of-function effects, as well as differential response to 4-aminopyridine treatment. Molecular dynamics simulations illustrate that the pore of the p.V469L variant is more constricted, increasing the energetic barrier for K+ permeation, whereas the p.V471L variant stabilizes the open conformation. Our results implicate variants in KCNC2 as causative for DEE and guide the interpretation of a UDN individual. They further delineate the molecular basis for the heterogeneous clinical phenotypes resulting from two proximal pathogenic variants. This demonstrates how the PSB approach can provide an analytical framework for individualized hypothesis-driven interpretation of protein-coding VUS.
Collapse
Affiliation(s)
- Souhrid Mukherjee
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Thomas A. Cassini
- Department of Internal Medicine, National Institutes of Health Clinical Center, Bethesda, MD 20814, USA
| | - Ningning Hu
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Tao Yang
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Bian Li
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Christopher W. Moth
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - David C. Rinker
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Jonathan H. Sheehan
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
- John T. Milliken Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joy D. Cogan
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Undiagnosed Diseases Network
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Pulmonary Hypertension Center, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- John T. Milliken Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Internal Medicine, National Institutes of Health Clinical Center, Bethesda, MD 20814, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, SAC 04103, Germany
- Department of Chemistry, Leipzig University, Leipzig, SAC 04109, Germany
- Department of Computer Science, Leipzig University, Leipzig, SAC 04109, Germany
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Bakar Computational Health Sciences Institute and Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John H. Newman
- Pulmonary Hypertension Center, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rizwan Hamid
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert L. Macdonald
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Dan M. Roden
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, SAC 04103, Germany
- Department of Chemistry, Leipzig University, Leipzig, SAC 04109, Germany
- Department of Computer Science, Leipzig University, Leipzig, SAC 04109, Germany
| | - Georg Kuenze
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, SAC 04103, Germany
| | - John A. Phillips
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - John A. Capra
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37235, USA
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Bakar Computational Health Sciences Institute and Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA 94143, USA
| |
Collapse
|
12
|
Gunthorpe MJ. Timing is everything: structural insights into the disease-linked Kv3 channels controlling fast action-potential firing in the brain. Nat Commun 2022; 13:4086. [PMID: 35840565 PMCID: PMC9287389 DOI: 10.1038/s41467-022-31537-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/21/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Martin J Gunthorpe
- Autifony Therapeutics Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK.
| |
Collapse
|
13
|
Pharmacological Screening of Venoms from Five Brazilian Micrurus Species on Different Ion Channels. Int J Mol Sci 2022; 23:ijms23147714. [PMID: 35887062 PMCID: PMC9318628 DOI: 10.3390/ijms23147714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 12/05/2022] Open
Abstract
Coral snake venoms from the Micrurus genus are a natural library of components with multiple targets, yet are poorly explored. In Brazil, 34 Micrurus species are currently described, and just a few have been investigated for their venom activities. Micrurus venoms are composed mainly of phospholipases A2 and three-finger toxins, which are responsible for neuromuscular blockade—the main envenomation outcome in humans. Beyond these two major toxin families, minor components are also important for the global venom activity, including Kunitz-peptides, serine proteases, 5′ nucleotidases, among others. In the present study, we used the two-microelectrode voltage clamp technique to explore the crude venom activities of five different Micrurus species from the south and southeast of Brazil: M. altirostris, M. corallinus, M. frontalis, M. carvalhoi and M. decoratus. All five venoms induced full inhibition of the muscle-type α1β1δε nAChR with different levels of reversibility. We found M. altirostris and M. frontalis venoms acting as partial inhibitors of the neuronal-type α7 nAChR with an interesting subsequent potentiation after one washout. We discovered that M. altirostris and M. corallinus venoms modulate the α1β2 GABAAR. Interestingly, the screening on KV1.3 showed that all five Micrurus venoms act as inhibitors, being totally reversible after the washout. Since this activity seems to be conserved among different species, we hypothesized that the Micrurus venoms may rely on potassium channel inhibitory activity as an important feature of their envenomation strategy. Finally, tests on NaV1.2 and NaV1.4 showed that these channels do not seem to be targeted by Micrurus venoms. In summary, the venoms tested are multifunctional, each of them acting on at least two different types of targets.
Collapse
|
14
|
Bushart DD, Shakkottai VG. Vulnerability of Human Cerebellar Neurons to Degeneration in Ataxia-Causing Channelopathies. Front Syst Neurosci 2022; 16:908569. [PMID: 35757096 PMCID: PMC9219590 DOI: 10.3389/fnsys.2022.908569] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/20/2022] [Indexed: 01/27/2023] Open
Abstract
Mutations in ion channel genes underlie a number of human neurological diseases. Historically, human mutations in ion channel genes, the so-called channelopathies, have been identified to cause episodic disorders. In the last decade, however, mutations in ion channel genes have been demonstrated to result in progressive neurodegenerative and neurodevelopmental disorders in humans, particularly with ion channels that are enriched in the cerebellum. This was unexpected given prior rodent ion channel knock-out models that almost never display neurodegeneration. Human ataxia-causing channelopathies that result in even haploinsufficiency can result in cerebellar atrophy and cerebellar Purkinje neuron loss. Rodent neurons with ion channel loss-of-function appear to, therefore, be significantly more resistant to neurodegeneration compared to human neurons. Fundamental differences in susceptibility of human and rodent cerebellar neurons in ataxia-causing channelopathies must therefore be present. In this review, we explore the properties of human neurons that may contribute to their vulnerability to cerebellar degeneration secondary to ion channel loss-of-function mutations. We present a model taking into account the known allometric scaling of neuronal ion channel density in humans and other mammals that may explain the preferential vulnerability of human cerebellar neurons to degeneration in ataxia-causing channelopathies. We also speculate on the vulnerability of cerebellar neurons to degeneration in mouse models of spinocerebellar ataxia (SCA) where ion channel transcript dysregulation has recently been implicated in disease pathogenesis.
Collapse
Affiliation(s)
- David D. Bushart
- Ohio State University College of Medicine, Columbus, OH, United States
| | - Vikram G. Shakkottai
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States,*Correspondence: Vikram G. Shakkottai,
| |
Collapse
|
15
|
Lange LM, Gonzalez-Latapi P, Rajalingam R, Tijssen MAJ, Ebrahimi-Fakhari D, Gabbert C, Ganos C, Ghosh R, Kumar KR, Lang AE, Rossi M, van der Veen S, van de Warrenburg B, Warner T, Lohmann K, Klein C, Marras C. Nomenclature of Genetic Movement Disorders: Recommendations of the International Parkinson and Movement Disorder Society Task Force - An Update. Mov Disord 2022; 37:905-935. [PMID: 35481685 DOI: 10.1002/mds.28982] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 12/13/2022] Open
Abstract
In 2016, the Movement Disorder Society Task Force for the Nomenclature of Genetic Movement Disorders presented a new system for naming genetically determined movement disorders and provided a criterion-based list of confirmed monogenic movement disorders. Since then, a substantial number of novel disease-causing genes have been described, which warrant classification using this system. In addition, with this update, we further refined the system and propose dissolving the imaging-based categories of Primary Familial Brain Calcification and Neurodegeneration with Brain Iron Accumulation and reclassifying these genetic conditions according to their predominant phenotype. We also introduce the novel category of Mixed Movement Disorders (MxMD), which includes conditions linked to multiple equally prominent movement disorder phenotypes. In this article, we present updated lists of newly confirmed monogenic causes of movement disorders. We found a total of 89 different newly identified genes that warrant a prefix based on our criteria; 6 genes for parkinsonism, 21 for dystonia, 38 for dominant and recessive ataxia, 5 for chorea, 7 for myoclonus, 13 for spastic paraplegia, 3 for paroxysmal movement disorders, and 6 for mixed movement disorder phenotypes; 10 genes were linked to combined phenotypes and have been assigned two new prefixes. The updated lists represent a resource for clinicians and researchers alike and they have also been published on the website of the Task Force for the Nomenclature of Genetic Movement Disorders on the homepage of the International Parkinson and Movement Disorder Society (https://www.movementdisorders.org/MDS/About/Committees--Other-Groups/MDS-Task-Forces/Task-Force-on-Nomenclature-in-Movement-Disorders.htm). © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.
Collapse
Affiliation(s)
- Lara M Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Paulina Gonzalez-Latapi
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada.,Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rajasumi Rajalingam
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | - Marina A J Tijssen
- UMCG Expertise Centre Movement Disorders, Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Carolin Gabbert
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Christos Ganos
- Department of Neurology, Charité University Hospital Berlin, Berlin, Germany
| | - Rhia Ghosh
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Kishore R Kumar
- Molecular Medicine Laboratory and Department of Neurology, Concord Repatriation General Hospital, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Anthony E Lang
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | - Malco Rossi
- Movement Disorders Section, Neuroscience Department, Raul Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina
| | - Sterre van der Veen
- UMCG Expertise Centre Movement Disorders, Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Center of Expertise for Parkinson and Movement Disorders, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Tom Warner
- Department of Clinical & Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Connie Marras
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | | |
Collapse
|
16
|
Lebenheim L, Booker SA, Derst C, Weiss T, Wagner F, Gruber C, Vida I, Zahm DS, Veh RW. A novel giant non-cholinergic striatal interneuron restricted to the ventrolateral striatum coexpresses Kv3.3 potassium channel, parvalbumin, and the vesicular GABA transporter. Mol Psychiatry 2022; 27:2315-2328. [PMID: 33190145 PMCID: PMC9126804 DOI: 10.1038/s41380-020-00948-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The striatum is the main input structure of the basal ganglia. Distinct striatal subfields are involved in voluntary movement generation and cognitive and emotional tasks, but little is known about the morphological and molecular differences of striatal subregions. The ventrolateral subfield of the striatum (VLS) is the orofacial projection field of the sensorimotor cortex and is involved in the development of orofacial dyskinesias, involuntary chewing-like movements that often accompany long-term neuroleptic treatment. The biological basis for this particular vulnerability of the VLS is not known. Potassium channels are known to be strategically localized within the striatum. In search of possible molecular correlates of the specific vulnerability of the VLS, we analyzed the expression of voltage-gated potassium channels in rodent and primate brains using qPCR, in situ hybridization, and immunocytochemical single and double staining. Here we describe a novel, giant, non-cholinergic interneuron within the VLS. This neuron coexpresses the vesicular GABA transporter, the calcium-binding protein parvalbumin (PV), and the Kv3.3 potassium channel subunit. This novel neuron is much larger than PV neurons in other striatal regions, displays characteristic electrophysiological properties, and, most importantly, is restricted to the VLS. Consequently, the giant striatal Kv3.3-expressing PV neuron may link compromised Kv3 channel function and VLS-based orofacial dyskinesias.
Collapse
Affiliation(s)
- Lydia Lebenheim
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany
| | - Sam A Booker
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Christian Derst
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany
| | - Torsten Weiss
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany
| | - Franziska Wagner
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany.,Hans Berger Klinik für Neurologie, Universitätsklinikum Jena, An der Klinik 1, D-07747, Jena, Germany
| | - Clemens Gruber
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany
| | - Imre Vida
- Institut für Integrative Neuroanatomie, Charité-Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany
| | - Daniel S Zahm
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA.
| | - Rüdiger W Veh
- Institut für Zell- und Neurobiologie, Charité -Universitätsmedizin Berlin, Philippstraße 12, D-10115, Berlin, Germany.
| |
Collapse
|
17
|
Martinez-Rojas VA, Juarez-Hernandez LJ, Musio C. Ion channels and neuronal excitability in polyglutamine neurodegenerative diseases. Biomol Concepts 2022; 13:183-199. [DOI: 10.1515/bmc-2022-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/14/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Polyglutamine (polyQ) diseases are a family composed of nine neurodegenerative inherited disorders (NDDs) caused by pathological expansions of cytosine-adenine-guanine (CAG) trinucleotide repeats which encode a polyQ tract in the corresponding proteins. CAG polyQ repeat expansions produce neurodegeneration via multiple downstream mechanisms; among those the neuronal activity underlying the ion channels is affected directly by specific channelopathies or indirectly by secondary dysregulation. In both cases, the altered excitability underlies to gain- or loss-of-function pathological effects. Here we summarize the repertoire of ion channels in polyQ NDDs emphasizing the biophysical features of neuronal excitability and their pathogenic role. The aim of this review is to point out the value of a deeper understanding of those functional mechanisms and processes as crucial elements for the designing and targeting of novel therapeutic avenues.
Collapse
Affiliation(s)
- Vladimir A. Martinez-Rojas
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
| | - Leon J. Juarez-Hernandez
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
| | - Carlo Musio
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
| |
Collapse
|
18
|
Ghorbani F, Alimohamed MZ, Vilacha JF, Van Dijk KK, De Boer-Bergsma J, Fokkens MR, Lemmink H, Sijmons RH, Sikkema-Raddatz B, Groves MR, Verschuuren-Bemelmans CC, Verbeek DS, Van Diemen CC, Westers H. Feasibility of Follow-Up Studies and Reclassification in Spinocerebellar Ataxia Gene Variants of Unknown Significance. Front Genet 2022; 13:782685. [PMID: 35401678 PMCID: PMC8990126 DOI: 10.3389/fgene.2022.782685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Spinocerebellar ataxia (SCA) is a heterogeneous group of neurodegenerative disorders with autosomal dominant inheritance. Genetic testing for SCA leads to diagnosis, prognosis and risk assessment for patients and their family members. While advances in sequencing and computing technologies have provided researchers with a rapid expansion in the genetic test content that can be used to unravel the genetic causes that underlie diseases, the large number of variants with unknown significance (VUSes) detected represent challenges. To minimize the proportion of VUSes, follow-up studies are needed to aid in their reclassification as either (likely) pathogenic or (likely) benign variants. In this study, we addressed the challenge of prioritizing VUSes for follow-up using (a combination of) variant segregation studies, 3D protein modeling, in vitro splicing assays and functional assays. Of the 39 VUSes prioritized for further analysis, 13 were eligible for follow up. We were able to reclassify 4 of these VUSes to LP, increasing the molecular diagnostic yield by 1.1%. Reclassification of VUSes remains difficult due to limited possibilities for performing variant segregation studies in the classification process and the limited availability of routine functional tests.
Collapse
Affiliation(s)
- Fatemeh Ghorbani
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Mohamed Z. Alimohamed
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Hematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Shree Hindu Mandal Hospital, Dar es Salaam, Tanzania
| | - Juliana F. Vilacha
- Groningen Biomolecular Sciences and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Krista K. Van Dijk
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Jelkje De Boer-Bergsma
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Michiel R. Fokkens
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Henny Lemmink
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Rolf H. Sijmons
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Birgit Sikkema-Raddatz
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Matthew R. Groves
- Structural Biology in Drug Design, Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | | | - Dineke S. Verbeek
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- *Correspondence: Dineke S. Verbeek,
| | - Cleo C. Van Diemen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Helga Westers
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| |
Collapse
|
19
|
Zhang Y, Quraishi IH, McClure H, Williams LA, Cheng Y, Kale S, Dempsey GT, Agrawal S, Gerber DJ, McManus OB, Kaczmarek LK. Suppression of Kv3.3 channels by antisense oligonucleotides reverses biochemical effects and motor impairment in spinocerebellar ataxia type 13 mice. FASEB J 2021; 35:e22053. [PMID: 34820911 DOI: 10.1096/fj.202101356r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/26/2021] [Accepted: 11/08/2021] [Indexed: 11/11/2022]
Abstract
Mutations in KCNC3, the gene that encodes the Kv3.3 voltage dependent potassium channel, cause Spinocerebellar Ataxia type 13 (SCA13), a disease associated with disrupted motor behaviors, progressive cerebellar degeneration, and abnormal auditory processing. The Kv3.3 channel directly binds Hax-1, a cell survival protein. A disease-causing mutation, Kv3.3-G592R, causes overstimulation of Tank Binding Kinase 1 (Tbk1) in the cerebellum, resulting in the degradation of Hax-1 by promoting its trafficking into multivesicular bodies and then to lysosomes. We have now tested the effects of antisense oligonucleotides (ASOs) directed against the Kv3.3 channel on both wild type mice and those bearing the Kv3.3-G592R-encoding mutation. Intracerebroventricular infusion of the Kcnc3-specific ASO suppressed both mRNA and protein levels of the Kv3.3 channel. In wild-type animals, this produced no change in levels of activated Tbk1, Hax-1 or Cd63, a tetraspanin marker for late endosomes/multivesicular bodies. In contrast, in mice homozygous for the Kv3.3-G592R-encoding mutation, the same ASO reduced Tbk1 activation and levels of Cd63, while restoring the expression of Hax-1 in the cerebellum. The motor behavior of the mice was tested using a rotarod assay. Surprisingly, the active ASO had no effects on the motor behavior of wild type mice but restored the behavior of the mutant mice to those of age-matched wild type animals. Our findings indicate that, in mature intact animals, suppression of Kv3.3 expression can reverse the deleterious effects of a SCA13 mutation while having little effect on wild type animals. Thus, targeting Kv3.3 expression may prove a viable therapeutic approach for SCA13.
Collapse
Affiliation(s)
- Yalan Zhang
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Imran H Quraishi
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Heather McClure
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | | | | | | | | | | | | | - Leonard K Kaczmarek
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
20
|
Benarroch E. What Is the Role of Potassium Channels in Ataxia? Neurology 2021; 97:938-941. [PMID: 34782409 DOI: 10.1212/wnl.0000000000012870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 11/15/2022] Open
|
21
|
Li X, Zheng Y, Li S, Nair U, Sun C, Zhao C, Lu J, Zhang VW, Maljevic S, Petrou S, Lin J. Kv3.1 channelopathy: a novel loss-of-function variant and the mechanistic basis of its clinical phenotypes. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1397. [PMID: 34733949 PMCID: PMC8506712 DOI: 10.21037/atm-21-1885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/11/2021] [Indexed: 11/26/2022]
Abstract
Background KCNC1 encodes Kv3.1, a subunit of the Kv3 voltage-gated potassium channels. It is predominantly expressed in inhibitory GABAergic interneurons and cerebellar neurons. Kv3.1 channelopathy has been linked to a variety of human diseases including epilepsy, developmental delay, and ataxia. Characterization of structural and functional disturbances of this channel, and its relationship to a heterogenous group of clinical phenotypes, is a current topic of research. We herein characterize the clinical phenotype as well as the functional and structural consequences of the novel KCNC1 p.R317S variant. We further set out to explore the mechanistic basis for the spectrum of KCNC1 related channelopathies. Methods Variant was identified via whole-exome sequencing and its functional impact was determined using two-electrode voltage clamp recordings in Xenopus laevis oocytes. Homolog modeling and in silico structural analysis were performed on the p.R317S variant and other KCNC1 related variants. Results We identified a novel loss-of-function KCNC1 variant c.949C>A (p.R317S) presenting with symptoms similar to myoclonic epilepsy and ataxia due to potassium channel (MEAK), but with distinct radiological features. Functional analysis in the Xenopus laevis oocyte’s expression system revealed that the current amplitudes were significantly decreased in the p.R317S variant compared to the wild type, indicating a dominant-negative effect. Atomic structural analysis of the KCNC1 related variants provided a possible mechanistic explanation for the heterogeneity in the clinical spectrum. Conclusions We have identified the p.R317S loss-of-function variant in the KCNC1 gene, expanded the spectrum of potassium channelopathy and provided mechanistic insights into KCNC1 related disorders.
Collapse
Affiliation(s)
- Xiaoyang Li
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.,Department of Neurology, University of North Carolina, Chapel Hill, USA
| | - Yongsheng Zheng
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | | | - Umesh Nair
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Chong Sun
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiahong Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | | | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Jie Lin
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
22
|
Abstract
The term SCA refers to a phenotypically and genetically heterogeneous group of autosomal dominant spinocerebellar ataxias. Phenotypically they present as gait ataxia frequently in combination with dysarthria and oculomotor problems. Additional signs and symptoms are common and can include various pyramidal and extrapyramidal signs and intellectual impairment. Genetic causes of SCAs are either repeat expansions within disease genes or common mutations (point mutations, deletions, insertions etc.). Frequently the two types of mutations cause indistinguishable phenotypes (locus heterogeneity). This article focuses on SCAs caused by common mutations. It describes phenotype and genotype of the presently 27 types known and discusses the molecular pathogenesis in those 21 types where the disease gene has been identified. Apart from the dominant types, the article also summarizes findings in a variant caused by mutations in a mitochondrial gene. Possible common disease mechanisms are considered based on findings in the various SCAs described.
Collapse
Affiliation(s)
- Ulrich Müller
- Institute of Human Genetics, JLU-Gießen, Schlangenzahl 14, 35392, Giessen, Germany.
| |
Collapse
|
23
|
Issa FA, Hall MK, Hatchett CJ, Weidner DA, Fiorenza AC, Schwalbe RA. Compromised N-Glycosylation Processing of Kv3.1b Correlates with Perturbed Motor Neuron Structure and Locomotor Activity. BIOLOGY 2021; 10:486. [PMID: 34070741 PMCID: PMC8229559 DOI: 10.3390/biology10060486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022]
Abstract
Neurological difficulties commonly accompany individuals suffering from congenital disorders of glycosylation, resulting from defects in the N-glycosylation pathway. Vacant N-glycosylation sites (N220 and N229) of Kv3, voltage-gated K+ channels of high-firing neurons, deeply perturb channel activity in neuroblastoma (NB) cells. Here we examined neuron development, localization, and activity of Kv3 channels in wildtype AB zebrafish and CRISPR/Cas9 engineered NB cells, due to perturbations in N-glycosylation processing of Kv3.1b. We showed that caudal primary (CaP) motor neurons of zebrafish spinal cord transiently expressing fully glycosylated (WT) Kv3.1b have stereotypical morphology, while CaP neurons expressing partially glycosylated (N220Q) Kv3.1b showed severe maldevelopment with incomplete axonal branching and extension around the ventral musculature. Consequently, larvae expressing N220Q in CaP neurons had impaired swimming locomotor activity. We showed that replacement of complex N-glycans with oligomannose attached to Kv3.1b and at cell surface lessened Kv3.1b dispersal to outgrowths by altering the number, size, and density of Kv3.1b-containing particles in membranes of rat neuroblastoma cells. Opening and closing rates were slowed in Kv3 channels containing Kv3.1b with oligomannose, instead of complex N-glycans, which suggested a reduction in the intrinsic dynamics of the Kv3.1b α-subunit. Thus, N-glycosylation processing of Kv3.1b regulates neuronal development and excitability, thereby controlling motor activity.
Collapse
Affiliation(s)
- Fadi A. Issa
- Department of Biology, East Carolina University, Greenville, NC 27858, USA;
| | - M. Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Cody J. Hatchett
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Douglas A. Weidner
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA;
| | - Alexandria C. Fiorenza
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Ruth A. Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| |
Collapse
|
24
|
Mueller CE, Richter-Bastian K, Bernhard F, Stuck BA, Birk R. [Obvious case of Morbus Menière?]. Laryngorhinootologie 2021; 100:472-476. [PMID: 33836548 DOI: 10.1055/a-1463-3536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Cornelia Emika Mueller
- Klinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie, Universitätsklinikum Gießen und Marburg - Standort Marburg, Germany
| | - Katrin Richter-Bastian
- Zentrum für unerkannte und seltene Erkrankungen, Universitätsklinikum Gießen und Marburg - Standort Marburg, Germany
| | - Felix Bernhard
- Klinik für Neurologie, Universitätsklinikum Gießen und Marburg - Standort Marburg, Germany
| | - Boris A Stuck
- Klinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie, Universitätsklinikum Gießen und Marburg - Standort Marburg, Germany
| | - Richard Birk
- Klinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie, Universitätsklinikum Gießen und Marburg - Standort Marburg, Germany
| |
Collapse
|
25
|
Cerebellar Kv3.3 potassium channels activate TANK-binding kinase 1 to regulate trafficking of the cell survival protein Hax-1. Nat Commun 2021; 12:1731. [PMID: 33741962 PMCID: PMC7979925 DOI: 10.1038/s41467-021-22003-8] [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: 05/10/2020] [Accepted: 02/22/2021] [Indexed: 02/06/2023] Open
Abstract
Mutations in KCNC3, which encodes the Kv3.3 potassium channel, cause degeneration of the cerebellum, but exactly how the activity of an ion channel is linked to the survival of cerebellar neurons is not understood. Here, we report that Kv3.3 channels bind and stimulate Tank Binding Kinase 1 (TBK1), an enzyme that controls trafficking of membrane proteins into multivesicular bodies, and that this stimulation is greatly increased by a disease-causing Kv3.3 mutation. TBK1 activity is required for the binding of Kv3.3 to its auxiliary subunit Hax-1, which prevents channel inactivation with depolarization. Hax-1 is also an anti-apoptotic protein required for survival of cerebellar neurons. Overactivation of TBK1 by the mutant channel leads to the loss of Hax-1 by its accumulation in multivesicular bodies and lysosomes, and also stimulates exosome release from neurons. This process is coupled to activation of caspases and increased cell death. Our studies indicate that Kv3.3 channels are directly coupled to TBK1-dependent biochemical pathways that determine the trafficking of cellular constituents and neuronal survival. How the activity of the neuronal Kv3.3 voltage-dependent channel is regulated is unclear. Here, the authors show that the known Kv3.3 channel complex with Hax1, which affects spinal cerebellar ataxia, regulates the enzyme Tank Binding Kinase 1, modulating survival of cerebellar neurons.
Collapse
|
26
|
Single-cell brain atlas of Parkinson's disease mouse model. J Genet Genomics 2021; 48:277-288. [PMID: 34052184 DOI: 10.1016/j.jgg.2021.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 12/26/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disease, leading to the impairment of movement execution. PD pathogenesis has been largely investigated, either limited to bulk transcriptomic levels or at certain cell types, which failed to capture the cellular heterogeneity and intrinsic interplays among distinct cell types. Here, we report the application of single-nucleus RNA-seq on midbrain, striatum, and cerebellum of the α-syn-A53T mouse, a well-established PD mouse model, and matched controls, generating the first single cell transcriptomic atlas for the PD model mouse brain composed of 46,174 individual cells. Additionally, we comprehensively depicte the dysfunctions in PD pathology, covering the elevation of NF-κB activity, the alteration of ion channel components, the perturbation of protein homeostasis network, and the dysregulation of glutamatergic signaling. Notably, we identify a variety of cell types closely associated with PD risk genes. Taken together, our study provides valuable resources to systematically dissect the molecular mechanism of PD pathogenesis at the single-cell resolution, which facilitates the development of novel approaches for diagnosis and therapies against PD.
Collapse
|
27
|
Quelle-Regaldie A, Sobrido-Cameán D, Barreiro-Iglesias A, Sobrido MJ, Sánchez L. Zebrafish Models of Autosomal Dominant Ataxias. Cells 2021; 10:421. [PMID: 33671313 PMCID: PMC7922657 DOI: 10.3390/cells10020421] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/13/2022] Open
Abstract
Hereditary dominant ataxias are a heterogeneous group of neurodegenerative conditions causing cerebellar dysfunction and characterized by progressive motor incoordination. Despite many efforts put into the study of these diseases, there are no effective treatments yet. Zebrafish models are widely used to characterize neuronal disorders due to its conserved vertebrate genetics that easily support genetic edition and their optic transparency that allows observing the intact CNS and its connections. In addition, its small size and external fertilization help to develop high throughput assays of candidate drugs. Here, we discuss the contributions of zebrafish models to the study of dominant ataxias defining phenotypes, genetic function, behavior and possible treatments. In addition, we review the zebrafish models created for X-linked repeat expansion diseases X-fragile/fragile-X tremor ataxia. Most of the models reviewed here presented neuronal damage and locomotor deficits. However, there is a generalized lack of zebrafish adult heterozygous models and there are no knock-in zebrafish models available for these diseases. The models created for dominant ataxias helped to elucidate gene function and mechanisms that cause neuronal damage. In the future, the application of new genetic edition techniques would help to develop more accurate zebrafish models of dominant ataxias.
Collapse
Affiliation(s)
- Ana Quelle-Regaldie
- Department of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary Science, Universidade of Santiago de Compostela, 27002 Lugo, Spain; (A.Q.-R.); (L.S.)
| | - Daniel Sobrido-Cameán
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - María Jesús Sobrido
- Instituto de Investigación Biomédica de A Coruña (INIBIC), Servicio Galego de Saúde, 15006 Coruña, Spain;
| | - Laura Sánchez
- Department of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary Science, Universidade of Santiago de Compostela, 27002 Lugo, Spain; (A.Q.-R.); (L.S.)
- Preclinical Animal Models Group, Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| |
Collapse
|
28
|
Bushart DD, Zalon AJ, Zhang H, Morrison LM, Guan Y, Paulson HL, Shakkottai VG, McLoughlin HS. Antisense Oligonucleotide Therapy Targeted Against ATXN3 Improves Potassium Channel-Mediated Purkinje Neuron Dysfunction in Spinocerebellar Ataxia Type 3. CEREBELLUM (LONDON, ENGLAND) 2021; 20:41-53. [PMID: 32789747 PMCID: PMC7930886 DOI: 10.1007/s12311-020-01179-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is the second-most common CAG repeat disease, caused by a glutamine-encoding expansion in the ATXN3 protein. SCA3 is characterized by spinocerebellar degeneration leading to progressive motor incoordination and early death. Previous studies suggest that potassium channel dysfunction underlies early abnormalities in cerebellar cortical Purkinje neuron firing in SCA3. However, cerebellar cortical degeneration is often modest both in the human disease and mouse models of SCA3, raising uncertainty about the role of cerebellar dysfunction in SCA3. Here, we address this question by investigating Purkinje neuron excitability in SCA3. In early-stage SCA3 mice, we confirm a previously identified increase in excitability of cerebellar Purkinje neurons and associate this excitability with reduced transcripts of two voltage-gated potassium (KV) channels, Kcna6 and Kcnc3, as well as motor impairment. Intracerebroventricular delivery of antisense oligonucleotides (ASO) to reduce mutant ATXN3 restores normal excitability to SCA3 Purkinje neurons and rescues transcript levels of Kcna6 and Kcnc3. Interestingly, while an even broader range of KV channel transcripts shows reduced levels in late-stage SCA3 mice, cerebellar Purkinje neuron physiology was not further altered despite continued worsening of motor impairment. These results suggest the progressive motor phenotype observed in SCA3 may not reflect ongoing changes in the cerebellar cortex but instead dysfunction of other neuronal structures within and beyond the cerebellum. Nevertheless, the early rescue of both KV channel expression and neuronal excitability by ASO treatment suggests that cerebellar cortical dysfunction contributes meaningfully to motor dysfunction in SCA3.
Collapse
Affiliation(s)
- David D. Bushart
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109
| | - Annie J. Zalon
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109
| | - Hongjiu Zhang
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI 48109,Microsoft, Inc. Bellevue, WA 98004
| | - Logan M. Morrison
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109
| | - Yuanfang Guan
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI 48109
| | - Henry L. Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109
| | - Vikram G. Shakkottai
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109,Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109,Address correspondence to: Vikram G. Shakkottai, 4009 BSRB, 109 Zina Pitcher Pl., Ann Arbor, MI 48109, ; Hayley S. McLoughlin, 4017 BSRB, 109 Zina Pitcher Pl., Ann Arbor, MI 48109,
| | - Hayley S. McLoughlin
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109,Address correspondence to: Vikram G. Shakkottai, 4009 BSRB, 109 Zina Pitcher Pl., Ann Arbor, MI 48109, ; Hayley S. McLoughlin, 4017 BSRB, 109 Zina Pitcher Pl., Ann Arbor, MI 48109,
| |
Collapse
|
29
|
Micro x-ray fluorescence analysis of trace element distribution in frozen hydrated HeLa cells at the P06 beamline at Petra III. Biointerphases 2021; 16:011004. [PMID: 33706519 DOI: 10.1116/6.0000593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
X-ray fluorescence analysis enables the study of trace element distributions in biological specimens. When this analysis is done under cryogenic conditions, cells are cryofixed as closely as possible to their natural physiological state, and the corresponding intracellular elemental densities can be analyzed. Details about the experimental setup used for analysis at the P06 beamline at Petra III, DESY and the used cryo-transfer system are described in this work. The system was applied to analyze the elemental distribution in single HeLa cells, a cell line frequently used in a wide range of biological applications. Cells adhered to silicon nitride substrates were cryoprotected within an amorphous ice matrix. Using a continuous scanning scheme and a KB x-ray focus, the distribution of elements in the cells was studied. We were able to image the intracellular potassium and zinc levels in HeLa cells as two key elements relevant for the physiology of cells.
Collapse
|
30
|
Gualdani R, Yuan JH, Effraim PR, Di Stefano G, Truini A, Cruccu G, Dib-Hajj SD, Gailly P, Waxman SG. Trigeminal Neuralgia TRPM8 Mutation: Enhanced Activation, Basal [Ca 2+] i and Menthol Response. NEUROLOGY-GENETICS 2021; 7:e550. [PMID: 33977138 PMCID: PMC8105906 DOI: 10.1212/nxg.0000000000000550] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/09/2020] [Indexed: 01/20/2023]
Abstract
Objective To assess the functional effects of a variant, c.89 G > A (p.Arg30Gln), in the transient receptor potential melastatin 8 (TRPM8) cold-sensing, nonselective cation channel, which we have previously identified in a patient with familial trigeminal neuralgia. Methods We carried out Ca2+ imaging and whole-cell patch-clamp recording. Results The TRPM8 mutation enhances channel activation, increases basal current amplitude and intracellular [Ca2+] in cells carrying the mutant channel, and enhances the response to menthol. Conclusions We propose that Arg30Gln confers gain-of-function attributes on TRPM8, which contribute to pathogenesis of trigeminal neuralgia in patients carrying this mutation.
Collapse
Affiliation(s)
- Roberta Gualdani
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Jun-Hui Yuan
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Philip R Effraim
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Giulia Di Stefano
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Andrea Truini
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Giorgio Cruccu
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Sulayman D Dib-Hajj
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Philippe Gailly
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| | - Stephen G Waxman
- Institute of Neuroscience (R.G., P.G.), Université catholique de Louvain, B-1200 Brussels, Belgium; Department of Neurology (J.-H.Y., S.D.D.-H., S.G.W.), Yale School of Medicine, New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; Department of Anaesthesiology (P.R.E.), Yale School of Medicine New Haven, CT and Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT; and Department of Human Neuroscience (G.D.S., A.T., G.C.), Sapienza University, Rome, Italy
| |
Collapse
|
31
|
Chopra R, Bushart DD, Cooper JP, Yellajoshyula D, Morrison LM, Huang H, Handler HP, Man LJ, Dansithong W, Scoles DR, Pulst SM, Orr HT, Shakkottai VG. Altered Capicua expression drives regional Purkinje neuron vulnerability through ion channel gene dysregulation in spinocerebellar ataxia type 1. Hum Mol Genet 2020; 29:3249-3265. [PMID: 32964235 PMCID: PMC7689299 DOI: 10.1093/hmg/ddaa212] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/19/2020] [Accepted: 09/17/2020] [Indexed: 12/22/2022] Open
Abstract
Selective neuronal vulnerability in neurodegenerative disease is poorly understood. Using the ATXN1[82Q] model of spinocerebellar ataxia type 1 (SCA1), we explored the hypothesis that regional differences in Purkinje neuron degeneration could provide novel insights into selective vulnerability. ATXN1[82Q] Purkinje neurons from the anterior cerebellum were found to degenerate earlier than those from the nodular zone, and this early degeneration was associated with selective dysregulation of ion channel transcripts and altered Purkinje neuron spiking. Efforts to understand the basis for selective dysregulation of channel transcripts revealed modestly increased expression of the ATXN1 co-repressor Capicua (Cic) in anterior cerebellar Purkinje neurons. Importantly, disrupting the association between ATXN1 and Cic rescued the levels of these ion channel transcripts, and lentiviral overexpression of Cic in the nodular zone accelerated both aberrant Purkinje neuron spiking and neurodegeneration. These findings reinforce the central role for Cic in SCA1 cerebellar pathophysiology and suggest that only modest reductions in Cic are needed to have profound therapeutic impact in SCA1.
Collapse
Affiliation(s)
- Ravi Chopra
- Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Neurology, Washington University in St. Louis, Saint Louis, MO 63110, USA
| | - David D Bushart
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
- Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - John P Cooper
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | | | - Logan M Morrison
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Haoran Huang
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Hillary P Handler
- Department of Laboratory Medicine and Pathology, Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Luke J Man
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Warunee Dansithong
- Department of Neurology, University of Utah, Salt Lake City, UT 84132, USA
| | - Daniel R Scoles
- Department of Neurology, University of Utah, Salt Lake City, UT 84132, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT 84132, USA
| | - Harry T Orr
- Department of Laboratory Medicine and Pathology, Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Vikram G Shakkottai
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
32
|
Middlebrooks JC, Waters MF. Spatial Mechanisms for Segregation of Competing Sounds, and a Breakdown in Spatial Hearing. Front Neurosci 2020; 14:571095. [PMID: 33041763 PMCID: PMC7525094 DOI: 10.3389/fnins.2020.571095] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/21/2020] [Indexed: 01/02/2023] Open
Abstract
We live in complex auditory environments, in which we are confronted with multiple competing sounds, including the cacophony of talkers in busy markets, classrooms, offices, etc. The purpose of this article is to synthesize observations from a series of experiments that focused on how spatial hearing might aid in disentangling interleaved sequences of sounds. The experiments were unified by a non-verbal task, "rhythmic masking release", which was applied to psychophysical studies in humans and cats and to cortical physiology in anesthetized cats. Human and feline listeners could segregate competing sequences of sounds from sources that were separated by as little as ∼10°. Similarly, single neurons in the cat primary auditory cortex tended to synchronize selectively to sound sequences from one of two competing sources, again with spatial resolution of ∼10°. The spatial resolution of spatial stream segregation varied widely depending on the binaural and monaural acoustical cues that were available in various experimental conditions. This is in contrast to a measure of basic sound-source localization, the minimum audible angle, which showed largely constant acuity across those conditions. The differential utilization of acoustical cues suggests that the central spatial mechanisms for stream segregation differ from those for sound localization. The highest-acuity spatial stream segregation was derived from interaural time and level differences. Brainstem processing of those cues is thought to rely heavily on normal function of a voltage-gated potassium channel, Kv3.3. A family was studied having a dominant negative mutation in the gene for that channel. Affected family members exhibited severe loss of sensitivity for interaural time and level differences, which almost certainly would degrade their ability to segregate competing sounds in real-world auditory scenes.
Collapse
Affiliation(s)
- John C. Middlebrooks
- Departments of Otolaryngology, Neurobiology and Behavior, Cognitive Sciences, and Biomedical Engineering, University of California, Irvine, Irvine, CA, United States
| | - Michael F. Waters
- Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, United States
| |
Collapse
|
33
|
Kim M, Oh SH, Cho JW, Lee JH. Spinocerebellar Ataxia 13 Presenting with Pure Cerebellar Syndrome in a Korean Family. J Mov Disord 2020; 13:244-246. [PMID: 32894899 PMCID: PMC7502298 DOI: 10.14802/jmd.20064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/21/2020] [Indexed: 11/24/2022] Open
Affiliation(s)
- Minkyeong Kim
- Department of Neurology, Gyeongsang National University Hospital, Jinju, Korea
| | - Seung Hwan Oh
- Department of Laboratory Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jae Wook Cho
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jae-Hyeok Lee
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| |
Collapse
|
34
|
KCND3-Related Neurological Disorders: From Old to Emerging Clinical Phenotypes. Int J Mol Sci 2020; 21:ijms21165802. [PMID: 32823520 PMCID: PMC7461103 DOI: 10.3390/ijms21165802] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
KCND3 encodes the voltage-gated potassium ion channel subfamily D member 3, a six trans-membrane protein (Kv4.3), involved in the transient outward K+ current. KCND3 defect causes both cardiological and neurological syndromes. From a neurological perspective, Kv4.3 defect has been associated to SCA type 19/22, a complex neurological disorder encompassing a wide spectrum of clinical features beside ataxia. To better define the phenotypic spectrum and course of KCND3-related neurological disorder, we review the clinical presentation and evolution in 68 reported cases. We delineated two main clinical phenotypes according to the age of onset. Neurodevelopmental disorder with epilepsy and/or movement disorders with ataxia later in the disease course characterized the early onset forms, while a prominent ataxic syndrome with possible cognitive decline, movement disorders, and peripheral neuropathy were observed in the late onset forms. Furthermore, we described a 37-year-old patient with a de novo KCND3 variant [c.901T>C (p.Ser301Pro)], previously reported in dbSNP as rs79821338, and a clinical phenotype paradigmatic of the early onset forms with neurodevelopmental disorder, epilepsy, parkinsonism-dystonia, and ataxia in adulthood, further expanding the clinical spectrum of this condition.
Collapse
|
35
|
Robinson KJ, Watchon M, Laird AS. Aberrant Cerebellar Circuitry in the Spinocerebellar Ataxias. Front Neurosci 2020; 14:707. [PMID: 32765211 PMCID: PMC7378801 DOI: 10.3389/fnins.2020.00707] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative diseases that share convergent disease features. A common symptom of these diseases is development of ataxia, involving impaired balance and motor coordination, usually stemming from cerebellar dysfunction and neurodegeneration. For most spinocerebellar ataxias, pathology can be attributed to an underlying gene mutation and the impaired function of the encoded protein through loss or gain-of-function effects. Strikingly, despite vast heterogeneity in the structure and function of disease-causing genes across the SCAs and the cellular processes affected, the downstream effects have considerable overlap, including alterations in cerebellar circuitry. Interestingly, aberrant function and degeneration of Purkinje cells, the major output neuronal population present within the cerebellum, precedes abnormalities in other neuronal populations within many SCAs, suggesting that Purkinje cells have increased vulnerability to cellular perturbations. Factors that are known to contribute to perturbed Purkinje cell function in spinocerebellar ataxias include altered gene expression resulting in altered expression or functionality of proteins and channels that modulate membrane potential, downstream impairments in intracellular calcium homeostasis and changes in glutamatergic input received from synapsing climbing or parallel fibers. This review will explore this enhanced vulnerability and the aberrant cerebellar circuitry linked with it in many forms of SCA. It is critical to understand why Purkinje cells are vulnerable to such insults and what overlapping pathogenic mechanisms are occurring across multiple SCAs, despite different underlying genetic mutations. Enhanced understanding of disease mechanisms will facilitate the development of treatments to prevent or slow progression of the underlying neurodegenerative processes, cerebellar atrophy and ataxic symptoms.
Collapse
Affiliation(s)
| | | | - Angela S. Laird
- Centre for Motor Neuron Disease Research, Department of Biomedical Science, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
36
|
Hsieh JY, Ulrich BN, Issa FA, Lin MCA, Brown B, Papazian DM. Infant and adult SCA13 mutations differentially affect Purkinje cell excitability, maturation, and viability in vivo. eLife 2020; 9:57358. [PMID: 32644043 PMCID: PMC7386905 DOI: 10.7554/elife.57358] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/08/2020] [Indexed: 12/23/2022] Open
Abstract
Mutations in KCNC3, which encodes the Kv3.3 K+ channel, cause spinocerebellar ataxia 13 (SCA13). SCA13 exists in distinct forms with onset in infancy or adulthood. Using zebrafish, we tested the hypothesis that infant- and adult-onset mutations differentially affect the excitability and viability of Purkinje cells in vivo during cerebellar development. An infant-onset mutation dramatically and transiently increased Purkinje cell excitability, stunted process extension, impaired dendritic branching and synaptogenesis, and caused rapid cell death during cerebellar development. Reducing excitability increased early Purkinje cell survival. In contrast, an adult-onset mutation did not significantly alter basal tonic firing in Purkinje cells, but reduced excitability during evoked high frequency spiking. Purkinje cells expressing the adult-onset mutation matured normally and did not degenerate during cerebellar development. Our results suggest that differential changes in the excitability of cerebellar neurons contribute to the distinct ages of onset and timing of cerebellar degeneration in infant- and adult-onset SCA13.
Collapse
Affiliation(s)
- Jui-Yi Hsieh
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States.,Interdepartmental PhD Program in Molecular, Cellular, and Integrative Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States
| | - Brittany N Ulrich
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States.,Interdepartmental PhD Program in Molecular, Cellular, and Integrative Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States
| | - Fadi A Issa
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States
| | - Meng-Chin A Lin
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States
| | - Brandon Brown
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States
| | - Diane M Papazian
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States.,Interdepartmental PhD Program in Molecular, Cellular, and Integrative Physiology, David Geffen School of Medicine at UCLA, Los Angeles, United States.,Brain Research Institute, UCLA, Los Angeles, United States.,Molecular Biology Institute, UCLA, Los Angeles, United States
| |
Collapse
|
37
|
Binda F, Pernaci C, Saxena S. Cerebellar Development and Circuit Maturation: A Common Framework for Spinocerebellar Ataxias. Front Neurosci 2020; 14:293. [PMID: 32300292 PMCID: PMC7145357 DOI: 10.3389/fnins.2020.00293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 03/13/2020] [Indexed: 01/24/2023] Open
Abstract
Spinocerebellar ataxias (SCAs) affect the cerebellum and its afferent and efferent systems that degenerate during disease progression. In the cerebellum, Purkinje cells (PCs) are the most vulnerable and their prominent loss in the late phase of the pathology is the main characteristic of these neurodegenerative diseases. Despite the constant advancement in the discovery of affected molecules and cellular pathways, a comprehensive description of the events leading to the development of motor impairment and degeneration is still lacking. However, in the last years the possible causal role for altered cerebellar development and neuronal circuit wiring in SCAs has been emerging. Not only wiring and synaptic transmission deficits are a common trait of SCAs, but also preventing the expression of the mutant protein during cerebellar development seems to exert a protective role. By discussing this tight relationship between cerebellar development and SCAs, in this review, we aim to highlight the importance of cerebellar circuitry for the investigation of SCAs.
Collapse
Affiliation(s)
- Francesca Binda
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Carla Pernaci
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Smita Saxena
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| |
Collapse
|
38
|
Rosini F, Pretegiani E, Battisti C, Dotti MT, Federico A, Rufa A. Eye movement changes in autosomal dominant spinocerebellar ataxias. Neurol Sci 2020; 41:1719-1734. [PMID: 32130555 DOI: 10.1007/s10072-020-04318-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 02/24/2020] [Indexed: 12/15/2022]
Abstract
Oculomotor abnormalities are common findings in spinocerebellar ataxias (SCAs), a clinically heterogeneous group of neurodegenerative disorders with an autosomal dominant pattern of inheritance. Usually, cerebellar impairment accounts for most of the eye movement changes encountered; as the disease progresses, the involvement of extracerebellar structures typically seen in later stages may modify the oculomotor progression. However, ocular movement changes are rarely specific. In this regard, some important exceptions include the prominent slowing of horizontal eye movements in SCA2 and, to a lesser extent, in SCA3, SCA4, and SCA28, or the executive deficit in SCA2 and SCA17. Here, we report the eye movement abnormalities and neurological pictures of SCAs through a review of the literature. Genetic and neuropathological/neuroimaging aspects are also briefly discussed. Overall, the findings reported indicate that oculomotor analysis could be of help in differential diagnosis among SCAs and contribute to clarify the role of brain structures, particularly the cerebellum, in oculomotor control.
Collapse
Affiliation(s)
- Francesca Rosini
- Department of Medicine Surgery and Neuroscience, Eye Tracking& Visual Application Lab EVALAB, Neurology and Neurometabolic Unit, University of Siena, Viale Bracci 2, 53100, Siena, Italy
| | - Elena Pretegiani
- Department of Medicine Surgery and Neuroscience, Eye Tracking& Visual Application Lab EVALAB, Neurology and Neurometabolic Unit, University of Siena, Viale Bracci 2, 53100, Siena, Italy
| | - Carla Battisti
- Department of Medicine, Surgery and Neuroscience, Neurology and Neurometabolic Unit, University of Siena, Siena, Italy
| | - Maria Teresa Dotti
- Department of Medicine, Surgery and Neuroscience, Neurology and Neurometabolic Unit, University of Siena, Siena, Italy
| | - Antonio Federico
- Department of Medicine, Surgery and Neuroscience, Neurology and Neurometabolic Unit, University of Siena, Siena, Italy
| | - Alessandra Rufa
- Department of Medicine Surgery and Neuroscience, Eye Tracking& Visual Application Lab EVALAB, Neurology and Neurometabolic Unit, University of Siena, Viale Bracci 2, 53100, Siena, Italy.
- Department of Medicine, Surgery and Neuroscience, Neurology and Neurometabolic Unit, University of Siena, Siena, Italy.
| |
Collapse
|
39
|
Tada Y, Kume K, Matsuda Y, Kurashige T, Kanaya Y, Ohsawa R, Morino H, Tabu H, Kaneko S, Suenaga T, Kakizuka A, Kawakami H. Genetic screening for potassium channel mutations in Japanese autosomal dominant spinocerebellar ataxia. J Hum Genet 2020; 65:363-369. [PMID: 31907387 DOI: 10.1038/s10038-019-0717-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/04/2019] [Accepted: 12/19/2019] [Indexed: 01/17/2023]
Abstract
Spinocerebellar ataxia (SCA) is a genetically heterogeneous disease characterized by cerebellar ataxia. Many causative genes have been identified to date, the most common etiology being the abnormal expansion of repeat sequences, and the mutation of ion channel genes also play an important role in the development of SCA. Some of them encode calcium and potassium channels. However, due to limited reports about potassium genes in SCA, we screened 192 Japanese individuals with dominantly inherited SCA who had no abnormal repeat expansions of causative genes for potassium channel mutations (KCNC3 for SCA13 and KCND3 for SCA19/SCA22) by target sequencing. As a result, two variants were identified from two patients: c.1973G>A, p.R658Q and c.1018G>A, p.V340M for KCNC3, and no pathogenic variant was identified for KCND3. The newly identified p.V340M exists in the extracellular domain, and p.R658Q exists in the intracellular domain on the C-terminal side, although most of the reported KCNC3 mutations are present at the transmembrane site. Adult-onset and slowly progressive cerebellar ataxia are the main clinical features of SCA13 and SCA19 caused by potassium channel mutations, which was similar in our cases. SCA13 caused by KCNC3 mutations may present with deep sensory loss and cognitive impairment in addition to cerebellar ataxia. In this study, mild deep sensory loss was observed in one case. SCA caused by potassium channel gene mutations is extremely rare, and more cases should be accumulated in the future to elucidate its pathogenesis due to channel dysfunction.
Collapse
Affiliation(s)
- Yui Tada
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.,Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kodai Kume
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Yukiko Matsuda
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Takashi Kurashige
- Department of Neurology, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Kure, Japan
| | - Yuhei Kanaya
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Ryosuke Ohsawa
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Hiroyuki Morino
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Hayato Tabu
- Department of Neurology, Kitano Hospital, Osaka, Japan
| | - Satoshi Kaneko
- Department of Neurology, Kansai Medical University, Osaka, Japan
| | | | - Akira Kakizuka
- Laboratory of Functional Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Hideshi Kawakami
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
| |
Collapse
|
40
|
Lalonde R, Strazielle C. Motor Performances of Spontaneous and Genetically Modified Mutants with Cerebellar Atrophy. THE CEREBELLUM 2019; 18:615-634. [PMID: 30820866 DOI: 10.1007/s12311-019-01017-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chance discovery of spontaneous mutants with atrophy of the cerebellar cortex has unearthed genes involved in optimizing motor coordination. Rotorod, stationary beam, and suspended wire tests are useful in delineating behavioral phenotypes of spontaneous mutants with cerebellar atrophy such as Grid2Lc, Grid2ho, Rorasg, Agtpbp1pcd, Relnrl, and Dab1scm. Likewise, transgenic or null mutants serving as experimental models of spinocerebellar ataxia (SCA) are phenotyped with the same tests. Among experimental models of autosomal dominant SCA, rotorod deficits were reported in SCA1 to 3, SCA5 to 8, SCA14, SCA17, and SCA27 and stationary beam deficits in SCA1 to 3, SCA5, SCA6, SCA13, SCA17, and SCA27. Beam tests are sensitive to experimental therapies of various kinds including molecules affecting glutamate signaling, mesenchymal stem cells, anti-oligomer antibodies, lentiviral vectors carrying genes, interfering RNAs, or neurotrophic factors, and interbreeding with other mutants.
Collapse
Affiliation(s)
- Robert Lalonde
- Department of Psychology, University of Rouen, 76821, Mont-Saint-Aignan Cedex, France.
| | - Catherine Strazielle
- Laboratory of Stress, Immunity, and Pathogens EA7300, and CHRU of Nancy, University of Lorraine, 54500, Vandoeuvre-les-Nancy, France
| |
Collapse
|
41
|
Palu RAS, Ong E, Stevens K, Chung S, Owings KG, Goodman AG, Chow CY. Natural Genetic Variation Screen in Drosophila Identifies Wnt Signaling, Mitochondrial Metabolism, and Redox Homeostasis Genes as Modifiers of Apoptosis. G3 (BETHESDA, MD.) 2019; 9:3995-4005. [PMID: 31570502 PMCID: PMC6893197 DOI: 10.1534/g3.119.400722] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/26/2019] [Indexed: 12/22/2022]
Abstract
Apoptosis is the primary cause of degeneration in a number of neuronal, muscular, and metabolic disorders. These diseases are subject to a great deal of phenotypic heterogeneity in patient populations, primarily due to differences in genetic variation between individuals. This creates a barrier to effective diagnosis and treatment. Understanding how genetic variation influences apoptosis could lead to the development of new therapeutics and better personalized treatment approaches. In this study, we examine the impact of the natural genetic variation in the Drosophila Genetic Reference Panel (DGRP) on two models of apoptosis-induced retinal degeneration: overexpression of p53 or reaper (rpr). We identify a number of known apoptotic, neural, and developmental genes as candidate modifiers of degeneration. We also use Gene Set Enrichment Analysis (GSEA) to identify pathways that harbor genetic variation that impact these apoptosis models, including Wnt signaling, mitochondrial metabolism, and redox homeostasis. Finally, we demonstrate that many of these candidates have a functional effect on apoptosis and degeneration. These studies provide a number of avenues for modifying genes and pathways of apoptosis-related disease.
Collapse
Affiliation(s)
- Rebecca A S Palu
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Elaine Ong
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Kaitlyn Stevens
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Shani Chung
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Katie G Owings
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Alan G Goodman
- School of Molecular Biosciences, and
- Paul G. Allen School for Global Animal Health, Washington State University College of Veterinary Medicine, Pullman, WA 99164
| | - Clement Y Chow
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112,
| |
Collapse
|
42
|
Namikawa K, Dorigo A, Köster RW. Neurological Disease Modelling for Spinocerebellar Ataxia Using Zebrafish. J Exp Neurosci 2019; 13:1179069519880515. [PMID: 31666796 PMCID: PMC6798160 DOI: 10.1177/1179069519880515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 01/02/2023] Open
Abstract
The cerebellum integrates sensory information and motor actions. Increasing
experimental evidence has revealed that these functions as well as the
cerebellar cytoarchitecture are highly conserved in zebrafish compared with
mammals. However, the potential of zebrafish for modelling human cerebellar
diseases remains to be addressed. Spinocerebellar ataxias (SCAs) represent a
group of genetically inherited cerebellar diseases leading to motor
discoordination that is most often caused by affected cerebellar Purkinje cells
(PCs). Towards modelling SCAs in zebrafish we identified a small-sized
PC-specific regulatory element that was used to develop coexpression vectors
with tunable expression strength. These vectors allow for in vivo imaging of
SCA-affected PCs by high-resolution fluorescence imaging. Next, zebrafish with
SCA type 13 (SCA13) transgene expression were established, revealing that
SCA13-induced cell-autonomous PC degeneration results in eye movement deficits.
Thus, SCA13 zebrafish mimic the neuropathology of an SCA-affected brain as well
as the involved loss of motor control and hence provide a powerful approach to
unravel SCA13-induced cell biological pathogenic and cytotoxic mechanisms.
Collapse
Affiliation(s)
- Kazuhiko Namikawa
- Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Alessandro Dorigo
- Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard W Köster
- Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| |
Collapse
|
43
|
Jędrychowska J, Korzh V. Kv2.1 voltage-gated potassium channels in developmental perspective. Dev Dyn 2019; 248:1180-1194. [PMID: 31512327 DOI: 10.1002/dvdy.114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/01/2019] [Accepted: 09/03/2019] [Indexed: 11/11/2022] Open
Abstract
Kv2.1 voltage-gated potassium channels consist of two types of α-subunits: (a) electrically-active Kcnb1 α-subunits and (b) silent or modulatory α-subunits plus β-subunits that, similar to silent α-subunits, also regulate electrically-active subunits. Voltage-gated potassium channels were traditionally viewed, mainly by electrophysiologists, as regulators of the electrical activity of the plasma membrane in excitable cells, a role that is performed by transmembrane protein domains of α-subunits that form the electric pore. Genetic studies revealed a role for this region of α-subunits of voltage-gated potassium channels in human neurodevelopmental disorders, such as epileptic encephalopathy. The N- and C-terminal domains of α-subunits interact to form the cytoplasmic subunit of heterotetrameric potassium channels that regulate electric pores. Subsequent animal studies revealed the developmental functions of Kcnb1-containing voltage-gated potassium channels and illustrated their role during brain development and reproduction. These functions of potassium channels are discussed in this review in the context of regulatory interactions between electrically-active and regulatory subunits.
Collapse
Affiliation(s)
- Justyna Jędrychowska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw, Poland
| | - Vladimir Korzh
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| |
Collapse
|
44
|
Srinivasan SR, Shakkottai VG. Moving Towards Therapy in SCA1: Insights from Molecular Mechanisms, Identification of Novel Targets, and Planning for Human Trials. Neurotherapeutics 2019; 16:999-1008. [PMID: 31338702 PMCID: PMC6985354 DOI: 10.1007/s13311-019-00763-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) are a group of neurodegenerative disorders inherited in an autosomal dominant fashion. The SCAs result in progressive gait imbalance, incoordination of the limbs, speech changes, and oculomotor dysfunction, among other symptoms. Over the past few decades, significant strides have been made in understanding the pathogenic mechanisms underlying these diseases. Although multiple efforts using a combination of genetics and pharmacology with small molecules have been made towards developing new therapeutics, no FDA approved treatment currently exists. In this review, we focus on SCA1, a common SCA subtype, in which some of the greatest advances have been made in understanding disease biology, and consequently potential therapeutic targets. Understanding of the underlying basic biology and targets of therapy in SCA1 is likely to give insight into treatment strategies in other SCAs. The diversity of the biology in the SCAs, and insight from SCA1 suggests, however, that both shared treatment strategies and specific approaches tailored to treat distinct genetic causes of SCA are likely needed for this group of devastating neurological disorders.
Collapse
Affiliation(s)
| | - Vikram G Shakkottai
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, 4009 BSRB, 109 Zina Pitcher Place, Ann Arbor, Michigan, 48109, USA.
| |
Collapse
|
45
|
Szpisjak L, Zadori D, Klivenyi P, Vecsei L. Clinical Characteristics and Possible Drug Targets in Autosomal Dominant Spinocerebellar Ataxias. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2019; 18:279-293. [DOI: 10.2174/1871527318666190311155846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/10/2018] [Accepted: 01/31/2019] [Indexed: 12/28/2022]
Abstract
Background & Objective:
The autosomal dominant spinocerebellar ataxias (SCAs) belong
to a large and expanding group of neurodegenerative disorders. SCAs comprise more than 40 subtypes
characterized by progressive ataxia as a common feature. The most prevalent diseases among SCAs
are caused by CAG repeat expansions in the coding-region of the causative gene resulting in polyglutamine
(polyQ) tract formation in the encoded protein. Unfortunately, there is no approved therapy to
treat cerebellar motor dysfunction in SCA patients. In recent years, several studies have been conducted
to recognize the clinical and pathophysiological aspects of the polyQ SCAs more accurately.
This scientific progress has provided new opportunities to develop promising gene therapies, including
RNA interference and antisense oligonucleotides.
Conclusion:
The aim of the current work is to give a brief summary of the clinical features of SCAs
and to review the cardinal points of pathomechanisms of the most common polyQ SCAs. In addition,
we review the last few year’s promising gene suppression therapies of the most frequent polyQ SCAs
in animal models, on the basis of which human trials may be initiated in the near future.
Collapse
Affiliation(s)
- Laszlo Szpisjak
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Denes Zadori
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Peter Klivenyi
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Laszlo Vecsei
- Department of Neurology, University of Szeged, Szeged, Hungary
| |
Collapse
|
46
|
Complementary Tuning of Na + and K + Channel Gating Underlies Fast and Energy-Efficient Action Potentials in GABAergic Interneuron Axons. Neuron 2019; 98:156-165.e6. [PMID: 29621485 PMCID: PMC5896255 DOI: 10.1016/j.neuron.2018.02.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/12/2018] [Accepted: 02/23/2018] [Indexed: 12/13/2022]
Abstract
Fast-spiking, parvalbumin-expressing GABAergic interneurons (PV+-BCs) express a complex machinery of rapid signaling mechanisms, including specialized voltage-gated ion channels to generate brief action potentials (APs). However, short APs are associated with overlapping Na+ and K+ fluxes and are therefore energetically expensive. How the potentially vicious combination of high AP frequency and inefficient spike generation can be reconciled with limited energy supply is presently unclear. To address this question, we performed direct recordings from the PV+-BC axon, the subcellular structure where active conductances for AP initiation and propagation are located. Surprisingly, the energy required for the AP was, on average, only ∼1.6 times the theoretical minimum. High energy efficiency emerged from the combination of fast inactivation of Na+ channels and delayed activation of Kv3-type K+ channels, which minimized ion flux overlap during APs. Thus, the complementary tuning of axonal Na+ and K+ channel gating optimizes both fast signaling properties and metabolic efficiency.
Collapse
|
47
|
Abstract
Spinocerebellar ataxia type 19 (SCA19), allelic with spinocerebellar ataxia type 22 (SCA22), is a rare syndrome caused by mutations in the KCND3 gene which encodes the potassium channel Kv4.3. Only 18 SCA19/22 families and sporadic cases of different ethnic backgrounds have been previously reported. As in other SCAs, the SCA19/22 phenotype is variable and usually consists of adult-onset slowly progressive ataxia and cognitive impairment; myoclonus and seizures; mild Parkinsonism occurs in some cases. Here we describe a Swedish SCA19/22 family spanning five generations and harboring the T377M mutation in KCND3. For the first time for this disease, 18F-fluorodeoxyglucose PET was assessed revealing widespread brain hypometabolism. In addition, we identified white matter abnormalities and found unusual features for SCA19/22 including early age of onset and fast rate of progression in the late course of disease in the oldest patient of this family.
Collapse
|
48
|
Noh W, Pak S, Choi G, Yang S, Yang S. Transient Potassium Channels: Therapeutic Targets for Brain Disorders. Front Cell Neurosci 2019; 13:265. [PMID: 31263403 PMCID: PMC6585177 DOI: 10.3389/fncel.2019.00265] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/28/2019] [Indexed: 01/04/2023] Open
Abstract
Transient potassium current channels (IA channels), which are expressed in most brain areas, have a central role in modulating feedforward and feedback inhibition along the dendroaxonic axis. Loss of the modulatory channels is tightly associated with a number of brain diseases such as Alzheimer’s disease, epilepsy, fragile X syndrome (FXS), Parkinson’s disease, chronic pain, tinnitus, and ataxia. However, the functional significance of IA channels in these diseases has so far been underestimated. In this review, we discuss the distribution and function of IA channels. Particularly, we posit that downregulation of IA channels results in neuronal (mostly dendritic) hyperexcitability accompanied by the imbalanced excitation and inhibition ratio in the brain’s networks, eventually causing the brain diseases. Finally, we propose a potential therapeutic target: the enhanced action of IA channels to counteract Ca2+-permeable channels including NMDA receptors could be harnessed to restore dendritic excitability, leading to a balanced neuronal state.
Collapse
Affiliation(s)
- Wonjun Noh
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - Sojeong Pak
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Geunho Choi
- Department of Computer Science and Engineering, Incheon National University, Incheon, South Korea
| | - Sungchil Yang
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Sunggu Yang
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| |
Collapse
|
49
|
Nicita F, Nardella M, Bellacchio E, Alfieri P, Terrone G, Piccini G, Graziola F, Pignata C, Capuano A, Bertini E, Zanni G. Heterozygous missense variants of SPTBN2 are a frequent cause of congenital cerebellar ataxia. Clin Genet 2019; 96:169-175. [PMID: 31066025 DOI: 10.1111/cge.13562] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/02/2019] [Accepted: 05/04/2019] [Indexed: 11/30/2022]
Abstract
Heterozygous missense variants in the SPTBN2 gene, encoding the non-erythrocytic beta spectrin 2 subunit (beta-III spectrin), have been identified in autosomal dominant spinocerebellar ataxia type 5 (SCA5), a rare adult-onset neurodegenerative disorder characterized by progressive cerebellar ataxia, whereas homozygous loss of function variants in SPTBN2 have been associated with early onset cerebellar ataxia and global developmental delay (SCAR14). Recently, heterozygous SPTBN2 missense variants have been identified in a few patients with an early-onset ataxic phenotype. We report five patients with non-progressive congenital ataxia and psychomotor delay, 4/5 harboring novel heterozygous missense variants in SPTBN2 and one patient with compound heterozygous SPTBN2 variants. With an overall prevalence of 5% in our cohort of unrelated patients screened by targeted next-generation sequencing (NGS) for congenital or early-onset cerebellar ataxia, this study indicates that both dominant and recessive mutations of SPTBN2 together with CACNA1A and ITPR1, are a frequent cause of early-onset/congenital non-progressive ataxia and that their screening should be implemented in this subgroup of disorders.
Collapse
Affiliation(s)
- Francesco Nicita
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Marta Nardella
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Emanuele Bellacchio
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, Rome, Italy
| | - Paolo Alfieri
- Unit of Child Neuropsychiatry, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Gaetano Terrone
- Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Giorgia Piccini
- Unit of Child Neuropsychiatry, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Federica Graziola
- Unit of Neurology, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Claudio Pignata
- Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Alessandro Capuano
- Unit of Neurology, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Enrico Bertini
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Ginevra Zanni
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| |
Collapse
|
50
|
Namikawa K, Dorigo A, Zagrebelsky M, Russo G, Kirmann T, Fahr W, Dübel S, Korte M, Köster RW. Modeling Neurodegenerative Spinocerebellar Ataxia Type 13 in Zebrafish Using a Purkinje Neuron Specific Tunable Coexpression System. J Neurosci 2019; 39:3948-3969. [PMID: 30862666 PMCID: PMC6520513 DOI: 10.1523/jneurosci.1862-18.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 02/19/2019] [Accepted: 02/25/2019] [Indexed: 12/17/2022] Open
Abstract
Purkinje cells (PCs) are primarily affected in neurodegenerative spinocerebellar ataxias (SCAs). For generating animal models for SCAs, genetic regulatory elements specifically targeting PCs are required, thereby linking pathological molecular effects with impaired function and organismic behavior. Because cerebellar anatomy and function are evolutionary conserved, zebrafish represent an excellent model to study SCAs in vivo We have isolated a 258 bp cross-species PC-specific enhancer element that can be used in a bidirectional manner for bioimaging of transgene-expressing PCs in zebrafish (both sexes) with variable copy numbers for tuning expression strength. Emerging ectopic expression at high copy numbers can be further eliminated by repurposing microRNA-mediated posttranslational mRNA regulation.Subsequently, we generated a transgenic SCA type 13 (SCA13) model, using a zebrafish-variant mimicking a human pathological SCA13R420H mutation, resulting in cell-autonomous progressive PC degeneration linked to cerebellum-driven eye-movement deficits as observed in SCA patients. This underscores that investigating PC-specific cerebellar neuropathologies in zebrafish allows for interconnecting bioimaging of disease mechanisms with behavioral analysis suitable for therapeutic compound testing.SIGNIFICANCE STATEMENT SCA13 patients carrying a KCNC3R420H allele have been shown to display mid-onset progressive cerebellar atrophy, but genetic modeling of SCA13 by expressing this pathogenic mutant in different animal models has not resulted in neuronal degeneration so far; likely because the transgene was expressed in heterologous cell types. We developed a genetic system for tunable PC-specific coexpression of several transgenes to manipulate and simultaneously monitor cerebellar PCs. We modeled a SCA13 zebrafish accessible for bioimaging to investigate disease progression, revealing robust PC degeneration, resulting in impaired eye movement. Our transgenic zebrafish mimicking both neuropathological and behavioral changes manifested in SCA-affected patients will be suitable for investigating causes of cerebellar diseases in vivo from the molecular to the behavioral level.
Collapse
Affiliation(s)
| | | | - Marta Zagrebelsky
- Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig 38106, Germany
| | - Giulio Russo
- Cellular and Molecular Neurobiology
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | | | - Wieland Fahr
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | - Stefan Dübel
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | - Martin Korte
- Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig 38106, Germany
- Research Group Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, Braunschweig 38106, Germany
| | | |
Collapse
|