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Abid F, Iqbal T, Khan K, Badshah Y, Trembley JH, Ashraf NM, Shabbir M, Afsar T, Almajwal A, Razak S. Analyzing PKC Gamma (+ 19,506 A/G) polymorphism as a promising genetic marker for HCV-induced hepatocellular carcinoma. Biomark Res 2022; 10:87. [PMID: 36451234 PMCID: PMC9714225 DOI: 10.1186/s40364-022-00437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/20/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND HCC is a major health concern worldwide. PKC gamma, a member of the conventional PKC subclass, is involved in many cancer types, but the protein has received little attention in the context of single nucleotide polymorphisms and HCC. Therefore, the study aims to investigate the association of PKC gamma missense SNP with HCV-induced hepatocellular carcinoma. METHODS The PKC gamma nsSNPs were retrieved from the ENSEMBL genome browser and the deleterious nsSNPs were filtered out through involvingPredictSNP2, CADD, DANN, FATHMM, FunSeq2 and GWAVA. Among the filtered nsSNPs, nsSNP rs1331262028 was identified to be the most pathogenic one. Through involving I-TASSER, ProjectHOPE, I-Mutant, MUpro, mCSM, SDM, DynaMut and MutPred, the influence of SNP rs1331262028 on protein structure, function and stability was estimated. A molecular Dynamic simulation was run to determine the conformational changes in mutant protein structure compared to wild. The blood samples were collected for genotyping analysis and for assessing ALT levels in the blood. RESULTS The study identified for the first time an SNP (rs1331262028) of PRKCG to strongly decrease protein stability and induce HCC. The RMSD, RMSF, and Rg values of mutant and wild types found were significantly different. Based on OR and RR values of 5.194 and 2.287, respectively, genotype analysis revealed a higher correlation between the SNP homozygous wild Typeform, AA, and the disease while patients with genotype AG have higher viral load. CONCLUSION Outcomes of the current study delineated PKC gamma SNP rs1331262028 as a genetic marker for HCV-induced HCC that could facilitate disease management after further validation.
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Affiliation(s)
- Fizzah Abid
- grid.412117.00000 0001 2234 2376Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Talha Iqbal
- grid.412117.00000 0001 2234 2376Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Khushbukhat Khan
- grid.412117.00000 0001 2234 2376Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Yasmin Badshah
- grid.412117.00000 0001 2234 2376Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Janeen H Trembley
- grid.410394.b0000 0004 0419 8667Minneapolis VA Health Care System Research Service, Minneapolis, MN USA ,grid.17635.360000000419368657Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN USA ,grid.17635.360000000419368657Masonic Cancer Center, University of Minnesota, Minneapolis, MN USA
| | - Naeem Mahmood Ashraf
- grid.11173.350000 0001 0670 519XSchool of Biochemistry and Biotechnology, University of the Punjab, Lahore, Pakistan
| | - Maria Shabbir
- grid.412117.00000 0001 2234 2376Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Tayyaba Afsar
- grid.56302.320000 0004 1773 5396Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, KSA Saudi Arabia
| | - Ali Almajwal
- grid.56302.320000 0004 1773 5396Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, KSA Saudi Arabia
| | - Suhail Razak
- grid.56302.320000 0004 1773 5396Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, KSA Saudi Arabia
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2
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Pilo CA, Baffi TR, Kornev AP, Kunkel MT, Malfavon M, Chen DH, Rossitto LA, Chen DX, Huang LC, Longman C, Kannan N, Raskind WH, Gonzalez DJ, Taylor SS, Gorrie G, Newton AC. Mutations in protein kinase Cγ promote spinocerebellar ataxia type 14 by impairing kinase autoinhibition. Sci Signal 2022; 15:eabk1147. [PMID: 36166510 PMCID: PMC9810342 DOI: 10.1126/scisignal.abk1147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spinocerebellar ataxia type 14 (SCA14) is a neurodegenerative disease caused by germline variants in the diacylglycerol (DAG)/Ca2+-regulated protein kinase Cγ (PKCγ), leading to Purkinje cell degeneration and progressive cerebellar dysfunction. Most of the identified mutations cluster in the DAG-sensing C1 domains. Here, we found with a FRET-based activity reporter that SCA14-associated PKCγ mutations, including a previously undescribed variant, D115Y, enhanced the basal activity of the kinase by compromising its autoinhibition. Unlike other mutations in PKC that impair its autoinhibition but lead to its degradation, the C1 domain mutations protected PKCγ from such down-regulation. This enhanced basal signaling rewired the brain phosphoproteome, as revealed by phosphoproteomic analysis of cerebella from mice expressing a human SCA14-associated H101Y mutant PKCγ transgene. Mutations that induced a high basal activity in vitro were associated with earlier average age of onset in patients. Furthermore, the extent of disrupted autoinhibition, but not agonist-stimulated activity, correlated with disease severity. Molecular modeling indicated that almost all SCA14 variants not within the C1 domain were located at interfaces with the C1B domain, suggesting that mutations in and proximal to the C1B domain are a susceptibility for SCA14 because they uniquely enhance PKCγ basal activity while protecting the enzyme from down-regulation. These results provide insight into how PKCγ activation is modulated and how deregulation of the cerebellar phosphoproteome by SCA14-associated mutations affects disease progression.
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Affiliation(s)
- Caila A. Pilo
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
- Biomedical Sciences Graduate Program, University of California, La Jolla, CA 92037, USA
| | - Timothy R. Baffi
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Alexandr P. Kornev
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Maya T. Kunkel
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Mario Malfavon
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Dong-Hui Chen
- Department of Neurology, University of Washington Seattle, WA 98195, USA
| | - Leigh-Ana Rossitto
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
- Biomedical Sciences Graduate Program, University of California, La Jolla, CA 92037, USA
| | - Daniel X. Chen
- Department of Neurology, University of Washington Seattle, WA 98195, USA
| | - Liang-Chin Huang
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Cheryl Longman
- Queen Elizabeth University Hospital, Glasgow, Scotland G51 4TF, United Kingdom
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Wendy H. Raskind
- Department of Medicine/Medical Genetics, University of Washington Seattle, WA 98195, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington Seattle, WA 98195, USA
- Mental Illness Research, Education and Clinical Center, Department of Veterans Affairs, Seattle, WA 98108, USA
| | - David J. Gonzalez
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Susan S. Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - George Gorrie
- Queen Elizabeth University Hospital, Glasgow, Scotland G51 4TF, United Kingdom
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
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Comparison of two families with and without ataxia harboring novel variants in PRKCG. J Hum Genet 2022; 67:595-599. [PMID: 35760954 DOI: 10.1038/s10038-022-01057-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 11/09/2022]
Abstract
Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant SCA caused by variants of the PRKCG encoding protein kinase C gamma (PKCγ). Although the toxic gain-of-function mechanism is the main cause of SCA14, its molecular pathophysiology remains unclear. To elucidate the molecular pathogenesis of SCA14, we analyzed two families with the variants in PRKCG. Clinical symptoms and neurological findings of two Japanese families were evaluated by neurologists. Exome sequencing was performed using the BGI platform. GFP-tagged PRKCGs harboring the identified variants were transfected into the HeLa cells, and aggregation of PKCγ was analyzed using confocal laser microscopy. Solubility of PKCγ was evaluated by assessing the proportion of insoluble fraction present in1% Triton-X. Patients in family 1 presented with only cerebellar atrophy without ataxia; however, patients in family 2 exhibited cerebellar ataxia, dystonia, and more severe cerebellar atrophy than those in family 1. Exome sequencing identified two novel missense variants of PRKCG:c.171 G > C,p.W57C (family 1), and c.400 T > C,p.C134R (family 2). Both the mutant PKCγ aggregated in the cytoplasm. Although the solubility of PKCγ of the C134R variant was lower than that of the wild-type, PKCγ of W57C retained its solubility. In conclusion, we identified two novel variants of PRKCG. The difference in severity between the two families may be due to the difference in solubility changes observed between the two variants. Decreased solubility of the PKCγ may play an important role in the pathogenesis of SCA14.
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4
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Pilo CA, Newton AC. Two Sides of the Same Coin: Protein Kinase C γ in Cancer and Neurodegeneration. Front Cell Dev Biol 2022; 10:929510. [PMID: 35800893 PMCID: PMC9253466 DOI: 10.3389/fcell.2022.929510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/23/2022] [Indexed: 12/23/2022] Open
Abstract
Protein kinase C (PKC) isozymes transduce myriad signals within the cell in response to the generation of second messengers from membrane phospholipids. The conventional isozyme PKCγ reversibly binds Ca2+ and diacylglycerol, which leads to an open, active conformation. PKCγ expression is typically restricted to neurons, but evidence for its expression in certain cancers has emerged. PKC isozymes have been labeled as oncogenes since the discovery that they bind tumor-promoting phorbol esters, however, studies of cancer-associated PKC mutations and clinical trial data showing that PKC inhibitors have worsened patient survival have reframed PKC as a tumor suppressor. Aberrant expression of PKCγ in certain cancers suggests a role outside the brain, although whether PKCγ also acts as a tumor suppressor remains to be established. On the other hand, PKCγ variants associated with spinocerebellar ataxia type 14 (SCA14), a neurodegenerative disorder characterized by Purkinje cell degeneration, enhance basal activity while preventing phorbol ester-mediated degradation. Although the basis for SCA14 Purkinje cell degeneration remains unknown, studies have revealed how altered PKCγ activity rewires cerebellar signaling to drive SCA14. Importantly, enhanced basal activity of SCA14-associated mutants inversely correlates with age of onset, supporting that enhanced PKCγ activity drives SCA14. Thus, PKCγ activity should likely be inhibited in SCA14, whereas restoring PKC activity should be the goal in cancer therapies. This review describes how PKCγ activity can be lost or gained in disease and the overarching need for a PKC structure as a powerful tool to predict the effect of PKCγ mutations in disease.
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Affiliation(s)
- Caila A. Pilo
- Department of Pharmacology, University of California, San Diego, San Diego, CA, United States
- Biomedical Sciences Graduate Program, University of California, San Diego, San Diego, CA, United States
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, San Diego, CA, United States
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5
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Louis ED, Faust PL. Essential Tremor Within the Broader Context of Other Forms of Cerebellar Degeneration. THE CEREBELLUM 2021; 19:879-896. [PMID: 32666285 DOI: 10.1007/s12311-020-01160-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Essential tremor (ET) has recently been reconceptualized by many as a degenerative disease of the cerebellum. Until now, though, there has been no attempt to frame it within the context of these diseases. Here, we compare the clinical and postmortem features of ET with other cerebellar degenerations, thereby placing it within the broader context of these diseases. Action tremor is the hallmark feature of ET. Although often underreported in the spinocerebellar ataxias (SCAs), action tremors occur, and it is noteworthy that in SCA12 and 15, they are highly prevalent, often severe, and can be the earliest disease manifestation, resulting in an initial diagnosis of ET in many cases. Intention tremor, sometimes referred to as "cerebellar tremor," is a common feature of ET and many SCAs. Other features of cerebellar dysfunction, gait ataxia and eye motion abnormalities, are seen to a mild degree in ET and more markedly in SCAs. Several SCAs (e.g., SCA5, 6, 14, and 15), like ET, follow a milder and more protracted disease course. In ET, numerous postmortem changes have been localized to the cerebellum and are largely confined to the cerebellar cortex, preserving the cerebellar nuclei. Purkinje cell loss is modest. Similarly, in SCA3, 12, and 15, Purkinje cell loss is limited, and in SCA12 and 15, there is preservation of cerebellar nuclei and relative sparing of other central nervous system regions. Both clinically and pathologically, there are numerous similarities and intersection points between ET and other disorders of cerebellar degeneration.
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Affiliation(s)
- Elan D Louis
- Department of Neurology and Therapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center and the New York Presbyterian Hospital, New York, NY, USA
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6
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Schmitz-Hübsch T, Lux S, Bauer P, Brandt AU, Schlapakow E, Greschus S, Scheel M, Gärtner H, Kirlangic ME, Gras V, Timmann D, Synofzik M, Giorgetti A, Carloni P, Shah JN, Schöls L, Kopp U, Bußenius L, Oberwahrenbrock T, Zimmermann H, Pfueller C, Kadas EM, Rönnefarth M, Grosch AS, Endres M, Amunts K, Paul F, Doss S, Minnerop M. Spinocerebellar ataxia type 14: refining clinicogenetic diagnosis in a rare adult-onset disorder. Ann Clin Transl Neurol 2021; 8:774-789. [PMID: 33739604 PMCID: PMC8045942 DOI: 10.1002/acn3.51315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/29/2020] [Accepted: 01/13/2021] [Indexed: 12/29/2022] Open
Abstract
Objectives Genetic variant classification is a challenge in rare adult‐onset disorders as in SCA‐PRKCG (prior spinocerebellar ataxia type 14) with mostly private conventional mutations and nonspecific phenotype. We here propose a refined approach for clinicogenetic diagnosis by including protein modeling and provide for confirmed SCA‐PRKCG a comprehensive phenotype description from a German multi‐center cohort, including standardized 3D MR imaging. Methods This cross‐sectional study prospectively obtained neurological, neuropsychological, and brain imaging data in 33 PRKCG variant carriers. Protein modeling was added as a classification criterion in variants of uncertain significance (VUS). Results Our sample included 25 cases confirmed as SCA‐PRKCG (14 variants, thereof seven novel variants) and eight carriers of variants assigned as VUS (four variants) or benign/likely benign (two variants). Phenotype in SCA‐PRKCG included slowly progressive ataxia (onset at 4–50 years), preceded in some by early‐onset nonprogressive symptoms. Ataxia was often combined with action myoclonus, dystonia, or mild cognitive‐affective disturbance. Inspection of brain MRI revealed nonprogressive cerebellar atrophy. As a novel finding, a previously not described T2 hyperintense dentate nucleus was seen in all SCA‐PRKCG cases but in none of the controls. Interpretation In this largest cohort to date, SCA‐PRKCG was characterized as a slowly progressive cerebellar syndrome with some clinical and imaging features suggestive of a developmental disorder. The observed non‐ataxia movement disorders and cognitive‐affective disturbance may well be attributed to cerebellar pathology. Protein modeling emerged as a valuable diagnostic tool for variant classification and the newly described T2 hyperintense dentate sign could serve as a supportive diagnostic marker of SCA‐PRKCG.
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Affiliation(s)
- Tanja Schmitz-Hübsch
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany.,Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Silke Lux
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,CENTOGENE AG, Rostock, Germany
| | - Alexander U Brandt
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany.,Department of Neurology, University of California, Irvine, CA, USA
| | - Elena Schlapakow
- Department of Neurology, University Hospital Bonn, Bonn, Germany.,Center for Rare Diseases, University of Bonn, Bonn, Germany
| | - Susanne Greschus
- Department of Radiology, University Hospital Bonn, Bonn, Germany
| | - Michael Scheel
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany.,Department of Neuroradiology, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Hanna Gärtner
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany
| | - Mehmet E Kirlangic
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany.,Institute for Biomedical Engineering and Computer Science, Technische Universität Ilmenau, Ilmenau, Germany
| | - Vincent Gras
- Institute of Neuroscience and Medicine (INM-4), Research Centre Juelich, Juelich, Germany
| | - Dagmar Timmann
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Center for Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Alejandro Giorgetti
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation (IAS-5) and Institute of Neuroscience and Medicine (INM-9), Research Centre Juelich, Juelich, Germany.,Department of Biotechnology, University of Verona, Verona, 37134, Italy
| | - Paolo Carloni
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation (IAS-5) and Institute of Neuroscience and Medicine (INM-9), Research Centre Juelich, Juelich, Germany
| | - Jon N Shah
- Institute of Neuroscience and Medicine (INM-4), Research Centre Juelich, Juelich, Germany.,Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Center for Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Ute Kopp
- Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Lisa Bußenius
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany.,Institute for Biochemistry and Molecular Cell Biology, Center for Experimental Medicine, University Clinic Hamburg Eppendorf, Hamburg, Germany
| | - Timm Oberwahrenbrock
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany
| | - Hanna Zimmermann
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany
| | - Caspar Pfueller
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany
| | - Ella-Maria Kadas
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany
| | - Maria Rönnefarth
- Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Anne-Sophie Grosch
- Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Matthias Endres
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany.,Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.,Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.,German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany.,C. and O. Vogt Institute for Brain Research, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Friedemann Paul
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health Berlin, Berlin, Germany.,Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.,Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Sarah Doss
- Klinik und Hochschulambulanz für Neurologie, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.,Movement Disorders Section, Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Martina Minnerop
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany.,Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.,Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
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Spinocerebellar ataxia type 14 caused by a nonsense mutation in the PRKCG gene. Mol Cell Neurosci 2019; 98:46-53. [PMID: 31158466 DOI: 10.1016/j.mcn.2019.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/25/2019] [Accepted: 05/30/2019] [Indexed: 12/15/2022] Open
Abstract
Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia with myoclonus, dystonia, spasticity, and rigidity. Although missense mutations and a deletion mutation have been found in the protein kinase C gamma (PRKCG) gene encoding protein kinase C γ (PKCγ) in SCA14 families, a nonsense mutation has not been reported. The patho-mechanisms underlying SCA14 remain poorly understood. However, gain-of-function mechanisms and loss-of-function mechanisms, but not dominant negative mechanisms, were reported the patho-mechanism of SCA14. We identified the c.226C>T mutation of PRKCG, which caused the p.R76X in PKCγ by whole-exome sequencing in patients presenting cerebellar atrophy with cognitive and hearing impairment. To investigate the patho-mechanism of our case, we studied aggregation formation, cell death, and PKC inhibitory effect by confocal microscopy, western blotting with cleaved caspase 3, and pSer PKC motif antibodies, respectively. PKCγ(R76X)-GFP have aggregations the same as wild-type (WT) PKCγ-GFP. The PKCγ(R76X)-GFP inhibited PKC phosphorylation activity more than GFP alone. It also induced more apoptosis in COS7 and SH-SY5Y cells compared to WT-PKCγ-GFP and GFP. We first reported SCA14 patients with p.R76X in PKCγ who have cerebellar atrophy with cognitive and hearing impairment. Our results suggest that a dominant negative mechanism due to truncated peptides produced by p.R76X may be at least partially responsible for the cerebellar atrophy.
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Abstract
Spinocerebellar ataxia type 8 (SCA8) is a rare autosomal dominant neurodegenerative disease caused by expanded CTA/CTG repeats in the ATXN8OS gene. Many patients had pure cerebellar ataxia, while some had parkinsonism, both without causal explanation. We analyzed the ATXN8OS gene in 150 Japanese patients with ataxia and 76 patients with Parkinson's disease or related disorders. We systematically reassessed 123 patients with SCA8, both our patients and those reported in other studies. Two patients with progressive supranuclear palsy (PSP) had mutations in the ATXN8OS gene. Systematic analyses revealed that patients with parkinsonism had significantly shorter CTA/CTG repeat expansions and older age at onset than those with predominant ataxia. We show the imaging results of patients with and without parkinsonism. We also found a significant inverse relationship between repeat sizes and age at onset in all patients, which has not been detected previously. Our results may be useful to genetic counseling, improve understanding of the pathomechanism, and extend the clinical phenotype of SCA8.
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9
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Shimobayashi E, Kapfhammer JP. Calcium Signaling, PKC Gamma, IP3R1 and CAR8 Link Spinocerebellar Ataxias and Purkinje Cell Dendritic Development. Curr Neuropharmacol 2018; 16:151-159. [PMID: 28554312 PMCID: PMC5883377 DOI: 10.2174/1570159x15666170529104000] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/16/2017] [Accepted: 05/25/2017] [Indexed: 01/05/2023] Open
Abstract
Background Spinocerebellar ataxias (SCAs) are a group of cerebellar diseases characterized by progressive ataxia and cerebellar atrophy. Several forms of SCAs are caused by missense mutations or deletions in genes related to calcium signaling in Purkinje cells. Among them, spinocerebellar ataxia type 14 (SCA14) is caused by missense mutations in PRKCG gene which encodes protein kinase C gamma (PKCγ). It is remarkable that in several cases in which SCA is caused by point mutations in an individual gene, the affected genes are involved in the PKCγ signaling pathway and calcium signaling which is not only crucial for proper Purkinje cell function but is also involved in the control of Purkinje cell dendritic development. In this review, we will focus on the PKCγ signaling related genes and calcium signaling related genes then discuss their role for both Purkinje cell dendritic development and cerebellar ataxia. Methods Research related to SCAs and Purkinje cell dendritic development is reviewed. Results PKCγ dysregulation causes abnormal Purkinje cell dendritic development and SCA14. Carbonic anhydrase related protein 8 (Car8) encoding CAR8 and Itpr1 encoding IP3R1were identified as upregulated genes in one of SCA14 mouse model. IP3R1, CAR8 and PKCγ proteins are strongly and specifically expressed in Purkinje cells. The common function among them is that they are involved in the regulation of calcium homeostasis in Purkinje cells and their dysfunction causes ataxia in mouse and human. Furthermore, disruption of intracellular calcium homeostasis caused by mutations in some calcium channels in Purkinje cells links to abnormal Purkinje cell dendritic development and the pathogenesis of several SCAs. Conclusion Once PKCγ signaling related genes and calcium signaling related genes are disturbed, the normal dendritic development of Purkinje cells is impaired as well as the integration of signals from other neurons, resulting in abnormal development, cerebellar dysfunction and eventually Purkinje cell loss.
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Affiliation(s)
- Etsuko Shimobayashi
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland
| | - Josef P Kapfhammer
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland
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10
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Wong MMK, Hoekstra SD, Vowles J, Watson LM, Fuller G, Németh AH, Cowley SA, Ansorge O, Talbot K, Becker EBE. Neurodegeneration in SCA14 is associated with increased PKCγ kinase activity, mislocalization and aggregation. Acta Neuropathol Commun 2018; 6:99. [PMID: 30249303 PMCID: PMC6151931 DOI: 10.1186/s40478-018-0600-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 01/30/2023] Open
Abstract
Spinocerebellar ataxia type 14 (SCA14) is a subtype of the autosomal dominant cerebellar ataxias that is characterized by slowly progressive cerebellar dysfunction and neurodegeneration. SCA14 is caused by mutations in the PRKCG gene, encoding protein kinase C gamma (PKCγ). Despite the identification of 40 distinct disease-causing mutations in PRKCG, the pathological mechanisms underlying SCA14 remain poorly understood. Here we report the molecular neuropathology of SCA14 in post-mortem cerebellum and in human patient-derived induced pluripotent stem cells (iPSCs) carrying two distinct SCA14 mutations in the C1 domain of PKCγ, H36R and H101Q. We show that endogenous expression of these mutations results in the cytoplasmic mislocalization and aggregation of PKCγ in both patient iPSCs and cerebellum. PKCγ aggregates were not efficiently targeted for degradation. Moreover, mutant PKCγ was found to be hyper-activated, resulting in increased substrate phosphorylation. Together, our findings demonstrate that a combination of both, loss-of-function and gain-of-function mechanisms are likely to underlie the pathogenesis of SCA14, caused by mutations in the C1 domain of PKCγ. Importantly, SCA14 patient iPSCs were found to accurately recapitulate pathological features observed in post-mortem SCA14 cerebellum, underscoring their potential as relevant disease models and their promise as future drug discovery tools.
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Affiliation(s)
- Maggie M. K. Wong
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Road, Oxford, OX1 3PT UK
| | - Stephanie D. Hoekstra
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Road, Oxford, OX1 3PT UK
| | - Jane Vowles
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE UK
| | - Lauren M. Watson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Road, Oxford, OX1 3PT UK
| | - Geraint Fuller
- Gloucestershire Hospitals, NHS Foundation Trust, Cheltenham General Hospital, Sandford Road, Cheltenham, GL53 7AN UK
| | - Andrea H. Németh
- Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford, OX3 9DU UK
- Oxford Centre for Genomic Medicine, ACE Building, Oxford University Hospitals NHS Trust, Nuffield Orthopaedic Centre, Windmill Road, Oxford, OX3 7HE UK
| | - Sally A. Cowley
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE UK
| | - Olaf Ansorge
- Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Esther B. E. Becker
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Road, Oxford, OX1 3PT UK
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11
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Nakazono A, Adachi N, Takahashi H, Seki T, Hamada D, Ueyama T, Sakai N, Saito N. Pharmacological induction of heat shock proteins ameliorates toxicity of mutant PKCγ in spinocerebellar ataxia type 14. J Biol Chem 2018; 293:14758-14774. [PMID: 30093405 DOI: 10.1074/jbc.ra118.002913] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/26/2018] [Indexed: 11/06/2022] Open
Abstract
Amyloid and amyloid-like protein aggregations are hallmarks of multiple, varied neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. We previously reported that spinocerebellar ataxia type 14 (SCA14), a dominant-inherited neurodegenerative disease that affects cerebellar Purkinje cells, is characterized by the intracellular formation of neurotoxic amyloid-like aggregates of genetic variants of protein kinase Cγ (PKCγ). A number of protein chaperones, including heat shock protein 70 (Hsp70), promote the degradation and/or refolding of misfolded proteins and thereby prevent their aggregation. Here, we report that, in various SCA14-associated, aggregating PKCγ variants, endogenous Hsp70 is incorporated into aggregates and that expression of these PKCγ mutants up-regulates Hsp70 expression. We observed that PKCγ binds Hsp70 and that this interaction is enhanced in the SCA14-associated variants, mediated by the kinase domain that is involved in amyloid-like fibril formation as well as the C2 domain of PKCγ. Pharmacological up-regulation of Hsp70 by the Hsp90 inhibitors celastrol and herbimycin A attenuated the aggregation of mutant PKCγ in primary cultured Purkinje cells. Up-regulation of Hsp70 diminished net PKCγ aggregation by preventing aggregate formation, resulting in decreased levels of apoptotic cell death among primary cultured Purkinje cells expressing the PKCγ variant. Of note, herbimycin A also ameliorated abnormal dendritic development. Extending our in vitro observations, administration of celastrol to mice up-regulated cerebellar Hsp70. Our findings identify heat shock proteins as important endogenous regulators of pathophysiological PKCγ aggregation and point to Hsp90 inhibition as a potential therapeutic strategy in the treatment of SCA14.
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Affiliation(s)
- Aoi Nakazono
- From the Biosignal Research Center, Kobe University, Kobe 657-8501
| | - Naoko Adachi
- From the Biosignal Research Center, Kobe University, Kobe 657-8501,
| | | | - Takahiro Seki
- the Department of Chemico-Pharmacological Sciences, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973
| | - Daizo Hamada
- the Graduate School of Engineering and.,Center for Applied Structural Science (CASS), Kobe University, 7-1-48 Minatojima Minami Machi, Chuo-ku, Kobe 650-0047, and
| | - Takehiko Ueyama
- From the Biosignal Research Center, Kobe University, Kobe 657-8501
| | - Norio Sakai
- the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8551, Japan
| | - Naoaki Saito
- From the Biosignal Research Center, Kobe University, Kobe 657-8501,
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12
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Chelban V, Wiethoff S, Fabian-Jessing BK, Haridy NA, Khan A, Efthymiou S, Becker EBE, O'Connor E, Hersheson J, Newland K, Hojland AT, Gregersen PA, Lindquist SG, Petersen MB, Nielsen JE, Nielsen M, Wood NW, Giunti P, Houlden H. Genotype-phenotype correlations, dystonia and disease progression in spinocerebellar ataxia type 14. Mov Disord 2018; 33:1119-1129. [PMID: 29603387 PMCID: PMC6175136 DOI: 10.1002/mds.27334] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 12/11/2022] Open
Abstract
Background: Spinocerebellar ataxia type 14 is a rare form of autosomal dominant cerebellar ataxia caused by mutations in protein kinase Cγ gene. Clinically, it presents with a slowly progressive, mainly pure cerebellar ataxia. Methods: Using next generation sequencing, we screened 194 families with autosomal dominant cerebellar ataxia and normal polyglutamine repeats. In‐depth phenotyping was performed using validated clinical rating scales neuroimaging and electrophysiological investigations. Results: We identified 25 individuals from 13 families carrying pathogenic mutations in protein kinase Cγ gene. A total of 10 unique protein kinase Cγ gene mutations have been confirmed of which 5 are novel and 5 were previously described. Our data suggest that the age at onset is highly variable; disease course is slowly progressive and rarely associated with severe disability. However, one third of patients presented with a complex ataxia comprising severe focal and/or task‐induced dystonia, peripheral neuropathy, parkinsonism, myoclonus, and pyramidal syndrome. The most complex phenotype is related to a missense mutation in the catalytic domain in exon 11. Conclusion: We present one of the largest genetically confirmed spinocerebellar ataxia type 14 cohorts contributing novel variants and clinical characterisation. We show that although protein kinase Cγ gene mutations present mainly as slowly progressive pure ataxia, more than a third of cases had a complex phenotype. Overall, our case series extends the phenotype and suggests that protein kinase Cγ gene mutations should be considered in patients with slowly progressive autosomal dominant cerebellar ataxia, particularly when myoclonus, dystonia, or mild cognitive impairment are present in the absence of polyglutamine expansion. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Viorica Chelban
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK.,Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Chisinau, Republic of Moldova
| | - Sarah Wiethoff
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,Center for Neurology and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, Tübingen, Germany
| | | | - Nourelhoda A Haridy
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,Department of Neurology and Psychiatry, Assiut University Hospital, Faculty of Medicine, Assiut, Egypt
| | - Alaa Khan
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Esther B E Becker
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Emer O'Connor
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Joshua Hersheson
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Katrina Newland
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | | | | | - Suzanne G Lindquist
- Danish Dementia Research Centre, Neurogenetics Clinic, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Michael B Petersen
- Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark
| | - Jørgen E Nielsen
- Danish Dementia Research Centre, Neurogenetics Clinic, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Michael Nielsen
- Department of Neurology, Aalborg University Hospital, Aalborg, Denmark
| | - Nicholas W Wood
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK
| | - Paola Giunti
- Deparmtent of Molecular Neuroscience, Ataxia Centre UCL, Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK
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13
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14
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van der Stijl R, Withoff S, Verbeek DS. Spinocerebellar ataxia: miRNAs expose biological pathways underlying pervasive Purkinje cell degeneration. Neurobiol Dis 2017; 108:148-158. [PMID: 28823930 DOI: 10.1016/j.nbd.2017.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/21/2017] [Accepted: 08/16/2017] [Indexed: 01/09/2023] Open
Abstract
Recent work has demonstrated the importance of miRNAs in the pathogenesis of various brain disorders including the neurodegenerative disorder spinocerebellar ataxia (SCA). This review focuses on the role of miRNAs in the shared pathogenesis of the different SCA types. We examine the novel findings of a recent cell-type-specific RNA-sequencing study in mouse brain and discuss how the identification of Purkinje-cell-enriched miRNAs highlights biological pathways that expose the mechanisms behind pervasive Purkinje cell degeneration in SCA. These key pathways are likely to contain targets for therapeutic development and represent potential candidate genes for genetically unsolved SCAs.
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Affiliation(s)
- Rogier van der Stijl
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Sebo Withoff
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Dineke S Verbeek
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
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15
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Shimobayashi E, Kapfhammer JP. Increased biological activity of protein Kinase C gamma is not required in Spinocerebellar ataxia 14. Mol Brain 2017; 10:34. [PMID: 28738819 PMCID: PMC5525338 DOI: 10.1186/s13041-017-0313-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/04/2017] [Indexed: 12/17/2022] Open
Abstract
Spinocerebellar ataxia (SCA) is an autosomal dominant neurodegenerative disorder characterized by slowly progressive cerebellar dysfunction. Currently, 42 SCA types are known, some of which are caused by CAG repeat expansions, but others are caused by point mutations or deletions. Spinocerebellar ataxia type 14 (SCA14) is caused by missense mutations or deletions in the PRKCG gene, coding for protein kinase C gamma (PKCγ). It is still not well understood how these mutations eventually cause Purkinje cell dysfunction and death. Because PKCγ is a well characterized signaling protein highly expressed in Purkinje cells SCA14 offers the chance to better understand the pathogenesis of Purkinje cell dysfunction and death. Altered biological activity of PKCγ would be the simplest explanation for the disease phenotype. There are indeed indications that the enzymatic activity of mutated PKCγ proteins could be changed. Many mutations found in SCA14 families are located in the regulatory C1B and C1A domain, while a few mutations are also found in the C2 and in the catalytic C3 and C4 domains. For many of these mutations an increased enzymatic activity could be demonstrated in cell-based assays, but it remains unclear whether there is indeed an altered biological activity of the mutated PKCγ proteins within living Purkinje cells. In this study we used the dendritic morphology of developing Purkinje cells to detect increased biological activity of PKCγ after expression of different mutated PKCγ proteins. Our results indicate that two out of three known mutations in the catalytic domain of PKCγ did indeed show increased biological activity. On the other hand, none of the five tested mutations located in the regulatory C1 or the C2 domain showed an increased biological activity. Our findings indicate that SCA14 mutations located in different domains of the PRKCG gene cause SCA14 by different mechanisms and that an increased constitutive activity of PKCγ may be one, but cannot be the only mechanism to cause disease in SCA14.
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Affiliation(s)
- Etsuko Shimobayashi
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, 4056, Basel, Switzerland.
| | - Josef P Kapfhammer
- Anatomical Institute, Department of Biomedicine Basel, University of Basel, Pestalozzistrasse 20, 4056, Basel, Switzerland
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16
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Jarius S, Wildemann B. 'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 2: Anti-PKC-gamma, anti-GluR-delta2, anti-Ca/ARHGAP26 and anti-VGCC. J Neuroinflammation 2015; 12:167. [PMID: 26377184 PMCID: PMC4574118 DOI: 10.1186/s12974-015-0357-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/02/2015] [Indexed: 01/18/2023] Open
Abstract
Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects, and provides a summary and outlook.
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Affiliation(s)
- S Jarius
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
| | - B Wildemann
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
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17
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Takahashi H, Adachi N, Shirafuji T, Danno S, Ueyama T, Vendruscolo M, Shuvaev AN, Sugimoto T, Seki T, Hamada D, Irie K, Hirai H, Sakai N, Saito N. Identification and characterization of PKCγ, a kinase associated with SCA14, as an amyloidogenic protein. Hum Mol Genet 2015; 24:525-39. [PMID: 25217572 DOI: 10.1093/hmg/ddu472] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Amyloid assemblies are associated with a wide range of human disorders, including Alzheimer's and Parkinson's diseases. Here, we identify protein kinase C (PKC) γ, a serine/threonine kinase mutated in the neurodegenerative disease spinocerebellar ataxia type 14 (SCA14), as a novel amyloidogenic protein with no previously characterized amyloid-prone domains. We found that overexpression of PKCγ in cultured cells, as well as in vitro incubation of PKCγ without heat or chemical denaturants, causes amyloid-like fibril formation of this protein. We also observed that SCA14-associated mutations in PKCγ accelerate the amyloid-like fibril formation both in cultured cells and in vitro. We show that the C1A and kinase domains of PKCγ are involved in its soluble dimer and aggregate formation and that SCA14-associated mutations in the C1 domain cause its misfolding and aggregation. Furthermore, long-term time-lapse imaging indicates that aggregates of mutant PKCγ are highly toxic to neuronal cells. Based on these findings, we propose that PKCγ could form amyloid-like fibrils in physiological and/or pathophysiological conditions such as SCA14. More generally, our results provide novel insights into the mechanism of amyloid-like fibril formation by multi-domain proteins.
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Affiliation(s)
| | - Naoko Adachi
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | | | - Sally Danno
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Takehiko Ueyama
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Michele Vendruscolo
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Anton N Shuvaev
- Department of Neurophysiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Takuya Sugimoto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Takahiro Seki
- Department of Chemico-Pharmacological Sciences, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
| | - Daizo Hamada
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan and
| | - Kazuhiro Irie
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8551, Japan
| | - Naoaki Saito
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
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18
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VCP gene analyses in Japanese patients with sporadic amyotrophic lateral sclerosis identify a new mutation. Neurobiol Aging 2014; 36:1604.e1-6. [PMID: 25457024 DOI: 10.1016/j.neurobiolaging.2014.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 10/12/2014] [Indexed: 12/11/2022]
Abstract
Accumulating evidence has proven that mutations in the VCP gene encoding valosin-containing protein (VCP) cause inclusion body myopathy with Paget disease of the bone and frontotemporal dementia. This gene was later found to be causative for amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, occurring typically in elderly persons. We thus sequenced the VCP gene in 75 Japanese patients with sporadic ALS negative for mutations in other genes causative for ALS and found a novel mutation, p.Arg487His, in 1 patient. The newly identified mutant as well as known mutants rendered neuronal cells susceptible to oxidative stress. The presence of the mutation in the Japanese population extends the geographic region for involvement of the VCP gene in sporadic ALS to East Asia.
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19
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APC rearrangements in familial adenomatous polyposis: heterogeneity of deletion lengths and breakpoint sequences underlies similar phenotypes. Fam Cancer 2014; 14:41-9. [DOI: 10.1007/s10689-014-9750-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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20
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Hoque M, Rentero C, Cairns R, Tebar F, Enrich C, Grewal T. Annexins — Scaffolds modulating PKC localization and signaling. Cell Signal 2014; 26:1213-25. [DOI: 10.1016/j.cellsig.2014.02.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/22/2014] [Indexed: 12/15/2022]
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21
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Menard C, Bastianetto S, Quirion R. Neuroprotective effects of resveratrol and epigallocatechin gallate polyphenols are mediated by the activation of protein kinase C gamma. Front Cell Neurosci 2013; 7:281. [PMID: 24421757 PMCID: PMC3872731 DOI: 10.3389/fncel.2013.00281] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/15/2013] [Indexed: 01/08/2023] Open
Abstract
Polyphenols such as epigallocatechin gallate (EGCG) and resveratrol have received a great deal of attention because they may contribute to the purported neuroprotective action of the regular consumption of green tea and red wine. Many studies, including those published by our group, suggest that this protective action includes their abilities to prevent the neurotoxic effects of beta-amyloid, a protein whose accumulation likely plays a pivotal role in Alzheimer's disease. Moreover, the scavenging activities of polyphenols on reactive oxygen species and their inhibitory action of cyclooxygenase likely explain, at least in part, their antioxidant and anti-inflammatory activities. Besides these well-documented properties, the modulatory action of these polyphenols on intracellular signaling pathways related to cell death/survival (e.g., protein kinase C, PKC) has yet to be investigated in detail. Using rat hippocampal neuronal cells, we aimed to investigate here the effects of EGCG and resveratrol on cell death induced by GF 109203X, a selective inhibitor of PKC. The MTT/resazurin and spectrin assays indicated that EGCG and resveratrol protected against GF 109203X-induced cell death and cytoskeleton degeneration, with a maximal effect at 1 and 3 μM, respectively. Moreover, immunofluorescence data revealed that cells treated with these polyphenols increased PKC gamma (γ) activation and promoted neuronal interconnections. Finally, we found that the protective effects of both polyphenols on the cytoskeleton and synaptic plasticity were mediated by the PKCγ subunit. Taken together, the results suggest that PKC, and more specifically its γ subunit, plays a critical role in the protective action of EGCG and resveratrol on neuronal integrity.
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Affiliation(s)
- Caroline Menard
- Laboratory of Neuroendocrinology of Aging, Centre Hospitalier de l'Université de Montréal Research Center Montreal, QC, Canada ; Department of Medicine, University of Montreal Montreal, QC, Canada ; Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Department of Psychiatry, McGill University Montreal, QC, Canada
| | - Stéphane Bastianetto
- Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Rémi Quirion
- Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Department of Psychiatry, McGill University Montreal, QC, Canada
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22
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Ikeda M, Hirano M, Shinoda K, Katsumata N, Furutama D, Nakamura K, Ikeda SI, Tanaka T, Hanafusa T, Kitajima H, Kohno H, Nakagawa M, Nakamura Y, Ueno S. Triple A syndrome in Japan. Muscle Nerve 2013; 48:381-6. [PMID: 23861206 DOI: 10.1002/mus.23770] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/24/2012] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Triple A syndrome is an autosomal recessive disease, characterized by esophageal achalasia, alacrima, and adrenal insufficiency, as well as involvement of the central, peripheral, and autonomic nervous systems. This disease mimics amyotrophic lateral sclerosis in some patients. The causative gene encodes ALADIN, a nuclear pore complex (NPC) component. Only 5 patients have been reported in Japan. METHODS We conducted the first nationwide survey of triple A syndrome. Identified mutants were expressed as GFP-fusion proteins in cultured cells. RESULTS Two new patients were identified, and 1 had a novel mutation (p.Ser182fsX19). All mutant proteins tested were mislocalized from NPC to cytoplasm. CONCLUSIONS The most consistent neurological manifestation of triple A syndrome in Japanese patients was progressive bulbospinal muscular atrophy with both upper and lower motor neuron involvement, which mimicked motor neuron disease, similar to that seen in patients in Western countries. The identification of the new patients suggests that more cases are undiagnosed in Japan.
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Affiliation(s)
- Masanori Ikeda
- Department of Neurology, Nara Medical University School of Medicine, Kashihara, Nara, Japan
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Abstract
DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease.
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Affiliation(s)
- Teruaki Iyama
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
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24
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Zeng L, Webster SV, Newton PM. The biology of protein kinase C. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:639-61. [PMID: 22453963 DOI: 10.1007/978-94-007-2888-2_28] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review gives a basic introduction to the biology of protein kinase C, one of the first calcium-dependent kinases to be discovered. We review the structure and function of protein kinase C, along with some of the substrates of individual isoforms. We then review strategies for inhibiting PKC in experimental systems and finally discuss the therapeutic potential of targeting PKC. Each aspect is covered in summary, with links to detailed resources where appropriate.
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Affiliation(s)
- Lily Zeng
- School of Medicine, University of California, San Francisco, CA, USA
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25
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Koht J, Stevanin G, Durr A, Mundwiller E, Brice A, Tallaksen CME. SCA14 in Norway, two families with autosomal dominant cerebellar ataxia and a novel mutation in the PRKCG gene. Acta Neurol Scand 2012; 125:116-22. [PMID: 21434874 DOI: 10.1111/j.1600-0404.2011.01504.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Despite a similar prevalence of autosomal dominant cerebellar ataxia (ADCA) in Norway compared to other European countries, less than 10% of the families are explained by the CAG trinucleotide expansions. We wanted to find the occurence of SCA14 in the dominant ataxia population and describe the phenotype. METHODS We screened a large dominant cerebellar ataxia cohort for mutations in the PRKCG gene. Patients were evaluated according to a standard clinical protocol for ataxia patients. RESULTS A novel mutation was found in two families, a C to A transversion altering Histidine to a Glutamine at codon 139, located in a highly concerved region in the gene. It completely co-segregated with the affected family members and was not seen in 576 control chromosomes. Genetic analysis revealed common alleles at three microsatellite markers between these two families suggesting a shared ancestral chromosome. Affected subjects displayed a mild, slowly progressive cerebellar syndrome that included gait and limb ataxia and saccadic pursuit and head tremor in one. Age at onset ranged from 10 to 45 years. CONCLUSIONS These are the first families with SCA14 reported from Scandinavia and a new mutation in the PRKCG gene. The occurrence in the Norwegian dominant ataxia cohort is 3.5%.
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26
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Abstract
SCA14 is an autosomal dominant hereditary cerebellar ataxia that usually has an onset in early to mid adult life, with slow progression and normal lifespan. Although generally an uncomplicated cerebellar ataxia with gait imbalance, dysarthria, and nystagmus, there is occasionally sensory loss, hyperactive tendon reflexes, cognitive decline, or myoclonus. Brain MRI shows cerebellar atrophy. A single autopsy has shown loss of cerebellar Purkinje cells. The disease is caused by mutations in the protein kinase C gamma (PKCγ, PRKCG) gene with a hotspot for mutations in exon 4. Genetic testing for SCA14 is clinically available.
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Affiliation(s)
- Dong-Hui Chen
- Department of Neurology, University of Washington, Seattle, WA, USA
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27
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Seki T, Adachi N, Abe-Seki N, Shimahara T, Takahashi H, Yamamoto K, Saito N, Sakai N. Elucidation of the molecular mechanism and exploration of novel therapeutics for spinocerebellar ataxia caused by mutant protein kinase Cγ. J Pharmacol Sci 2011; 116:239-47. [PMID: 21666345 DOI: 10.1254/jphs.11r04cp] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Spinocerebellar ataxia (SCA) is an inherited neurodegenerative disorder that is characterized by cerebellar atrophy and progressive ataxia and is classified into 31 types by the genetic locus. Recently, missense mutations of PRKCG genes that code protein kinase Cγ (γPKC) have been identified as a causal gene of SCA14. To explore the molecular mechanism of SCA14 pathogenesis, we investigated how mutant γPKC causes the neurodegeneration of cerebellar Purkinje cells (PCs) by expressing mutant γPKC-GFP in cell lines and primary cultured PCs. Mutant γPKC was susceptible to aggregation in the cytoplasm, which led to an impairment of the ubiquitin-proteasome system and apoptosis. Furthermore, mutant γPKC induced improper dendritic development of cultured PCs in an aggregation-independent manner. Stimulation-induced translocation of mutant γPKC in PC dendrites was prominently attenuated by the reduced mobility of oligomerized mutant γPKC, which resulted in attenuated signal transduction and the improper morphology of PC dendrites. These findings suggested that the oligomerization and aggregation of mutant γPKC caused improper dendritic development and apoptosis of PCs, which led to cerebellar dysfunction and SCA14 pathogenesis. We screened the chemicals that improved these cellular dysfunctions and identified several compounds, including trehalose and Congo red, which could be novel therapeutics for SCA14.
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Affiliation(s)
- Takahiro Seki
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
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28
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Marelli C, Cazeneuve C, Brice A, Stevanin G, Dürr A. Autosomal dominant cerebellar ataxias. Rev Neurol (Paris) 2011; 167:385-400. [PMID: 21546047 DOI: 10.1016/j.neurol.2011.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 01/27/2011] [Indexed: 12/30/2022]
Abstract
Cerebellar ataxias with autosomal dominant transmission (ADCA) are far rarer than sporadic cases of cerebellar ataxia. The identification of genes involved in dominant forms has confirmed the genetic heterogeneity of these conditions and of the underlying mechanisms and pathways. To date, at least 28 genetic loci and, among them, 20 genes have been identified. In many instances, the phenotype is not restricted to cerebellar dysfunction but includes more complex multisystemic neurological deficits. Seven ADCA (SCA1, 2, 3, 6, 7, 17, and dentatorubro-pallido-luysian atrophy) are caused by repeat expansions in the corresponding proteins; phenotype-genotype correlations have shown that repeat size influences the progression of the disease, its severity and clinical differences among patients, including the phenomenon of anticipation between generations. All other ADCA are caused either by non-coding repeat expansions, conventional mutations or large rearrangements in genes with different functions. This review will focus on the genetic features of ADCA and on the clinical differences among the different forms.
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Affiliation(s)
- C Marelli
- Département de génétique et cytogénétique, consultation de génétique clinique, CHU Pitié-Salpêtrière, AP-HP, 47, boulevard de l'Hôpital, 75013 Paris, France
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29
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Aprataxin localizes to mitochondria and preserves mitochondrial function. Proc Natl Acad Sci U S A 2011; 108:7437-42. [PMID: 21502511 DOI: 10.1073/pnas.1100084108] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ataxia with oculomotor apraxia 1 is caused by mutation in the APTX gene, which encodes the DNA strand-break repair protein aprataxin. Aprataxin exhibits homology to the histidine triad superfamily of nucleotide hydrolases and transferases and removes 5'-adenylate groups from DNA that arise from aborted ligation reactions. We report herein that aprataxin localizes to mitochondria in human cells and we identify an N-terminal amino acid sequence that targets certain isoforms of the protein to this intracellular compartment. We also show that transcripts encoding this unique N-terminal stretch are expressed in the human brain, with highest production in the cerebellum. Depletion of aprataxin in human SH-SY5Y neuroblastoma cells and primary skeletal muscle myoblasts results in mitochondrial dysfunction, which is revealed by reduced citrate synthase activity and mtDNA copy number. Moreover, mtDNA, not nuclear DNA, was found to have higher levels of background DNA damage on aprataxin knockdown, suggesting a direct role for the enzyme in mtDNA processing.
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30
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Seki T, Takahashi H, Yamamoto K, Ogawa K, Onji T, Adachi N, Tanaka S, Hide I, Saito N, Sakai N. Congo red, an amyloid-inhibiting compound, alleviates various types of cellular dysfunction triggered by mutant protein kinase cγ that causes spinocerebellar ataxia type 14 (SCA14) by inhibiting oligomerization and aggregation. J Pharmacol Sci 2011; 114:206-16. [PMID: 20938103 DOI: 10.1254/jphs.10170fp] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Several missense mutations in the protein kinase Cγ (γPKC) gene have been found to cause spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that the mutant γPKC found in SCA14 is susceptible to aggregation that induces apoptotic cell death. Congo red is widely used as a histological dye for amyloid detection. Recent evidence has revealed that Congo red has the property to inhibit amyloid oligomers and fibril formation of misfolded proteins. In the present study, we examine whether Congo red inhibits aggregate formation and cytotoxicity of mutant γPKC. Congo red likely inhibits aggregate formation of mutant γPKC – green fluorescent protein (GFP) without affecting its expression level in SH-SY5Y cells. Congo red counteracts the insolubilization of recombinant mutant γPKC, suggesting that the dye inhibits aggregation of mutant γPKC by a direct mechanism. Congo red also inhibits aggregation and oligomerization of mutant γPKC-GFP in primary cultured cerebellar Purkinje cells. Moreover, the dye reverses the improper development of dendrites and inhibits apoptotic cell death in Purkinje cells that express mutant γPKC-GFP. These results indicate that amyloid-inhibiting compounds like Congo red may be novel therapeutics for SCA14.
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Affiliation(s)
- Takahiro Seki
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan
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31
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Seki T, Abe-Seki N, Kikawada T, Takahashi H, Yamamoto K, Adachi N, Tanaka S, Hide I, Saito N, Sakai N. Effect of trehalose on the properties of mutant {gamma}PKC, which causes spinocerebellar ataxia type 14, in neuronal cell lines and cultured Purkinje cells. J Biol Chem 2010; 285:33252-33264. [PMID: 20705605 DOI: 10.1074/jbc.m110.146704] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Several missense mutations in the protein kinase Cγ (γPKC) gene have been found to cause spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that the mutant γPKC found in SCA14 is susceptible to aggregation, which induces apoptotic cell death. The disaccharide trehalose has been reported to inhibit aggregate formation and to alleviate symptoms in cellular and animal models of Huntington disease, Alzheimer disease, and prion disease. Here, we show that trehalose can be incorporated into SH-SY5Y cells and reduces the aggregation of mutant γPKC-GFP, thereby inhibiting apoptotic cell death in SH-SY5Y cells and primary cultured Purkinje cells (PCs). Trehalose acts by directly stabilizing the conformation of mutant γPKC without affecting protein turnover. Trehalose was also found to alleviate the improper development of dendrites in PCs expressing mutant γPKC-GFP without aggregates but not in PCs with aggregates. In PCs without aggregates, trehalose improves the mobility and translocation of mutant γPKC-GFP, probably by inhibiting oligomerization and thereby alleviating the improper development of dendrites. These results suggest that trehalose counteracts various cellular dysfunctions that are triggered by mutant γPKC in both neuronal cell lines and primary cultured PCs by inhibiting oligomerization and aggregation of mutant γPKC.
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Affiliation(s)
- Takahiro Seki
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551
| | - Nana Abe-Seki
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551
| | - Takahiro Kikawada
- National Institute of Agrobiological Sciences, Ohwashi 1-2, Tsukuba, Ibaraki 305-8634
| | - Hideyuki Takahashi
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Kazuhiro Yamamoto
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551
| | - Naoko Adachi
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Shigeru Tanaka
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551
| | - Izumi Hide
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Norio Sakai
- From the Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551.
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