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Silva Dos Santos F, Neves RAF, Bernay B, Krepsky N, Teixeira VL, Artigaud S. The first use of LC-MS/MS proteomic approach in the brown mussel Perna perna after bacterial challenge: Searching for key proteins on immune response. FISH & SHELLFISH IMMUNOLOGY 2023; 134:108622. [PMID: 36803779 DOI: 10.1016/j.fsi.2023.108622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
The brown mussel Perna perna is a valuable fishing resource, primarily in tropical and subtropical coastal regions. Because of their filter-feeding habits, mussels are directly exposed to bacteria in the water column. Escherichia coli (EC) and Salmonella enterica (SE) inhabit human guts and reach the marine environment through anthropogenic sources, such as sewage. Vibrio parahaemolyticus (VP) is indigenous to coastal ecosystems but can be harmful to shellfish. In this study, we aimed to assess the protein profile of the hepatopancreas of P. perna mussel challenged by introduced - E. coli and S. enterica - and indigenous marine bacteria - V. parahaemolyticus. Bacterial-challenge groups were compared with non-injected (NC) and injected control (IC) - that consisted in mussels not challenged and mussels injected with sterile PBS-NaCl, respectively. Through LC-MS/MS proteomic analysis, 3805 proteins were found in the hepatopancreas of P. perna. From the total, 597 were significantly different among conditions. Mussels injected with VP presented 343 proteins downregulated compared with all the other conditions, suggesting that VP suppresses their immune response. Particularly, 31 altered proteins - upregulated or downregulated - for one or more challenge groups (EC, SE, and VP) compared with controls (NC and IC) are discussed in detail in the paper. For the three tested bacteria, significantly different proteins were found to perform critical roles in immune response at all levels, namely: recognition and signal transduction; transcription; RNA processing; translation and protein processing; secretion; and humoral effectors. This is the first shotgun proteomic study in P. perna mussel, therefore providing an overview of the protein profile of the mussel hepatopancreas, focused on the immune response against bacteria. Hence, it is possible to understand the immune-bacteria relationship at molecular levels better. This knowledge can support the development of strategies and tools to be applied to coastal marine resource management and contribute to the sustainability of coastal systems.
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Affiliation(s)
- Fernanda Silva Dos Santos
- Graduate Program in Sciences and Biotechnology, Institute of Biology, Fluminense Federal University (UFF), R. Mario Santos Braga, S/n. Centro, Niterói, RJ, CEP 24.020-141, Brazil; Research Group of Experimental and Aquatic Ecology, Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458-307, Urca, Rio de Janeiro, RJ, CEP: 22.290-240, Brazil.
| | - Raquel A F Neves
- Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil; Research Group of Experimental and Aquatic Ecology, Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458-307, Urca, Rio de Janeiro, RJ, CEP: 22.290-240, Brazil.
| | - Benoît Bernay
- Plateforme Proteogen, SFR ICORE 4206, Université de Caen Basse-Normandie, Esplanade de la paix, 14032, Caen cedex, France.
| | - Natascha Krepsky
- Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil.
| | - Valéria Laneuville Teixeira
- Graduate Program in Sciences and Biotechnology, Institute of Biology, Fluminense Federal University (UFF), R. Mario Santos Braga, S/n. Centro, Niterói, RJ, CEP 24.020-141, Brazil; Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil.
| | - Sébastien Artigaud
- Université de Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzané, France.
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2
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Gilsoul M, Grisar T, Delgado-Escueta AV, de Nijs L, Lakaye B. Subtle Brain Developmental Abnormalities in the Pathogenesis of Juvenile Myoclonic Epilepsy. Front Cell Neurosci 2019; 13:433. [PMID: 31611775 PMCID: PMC6776584 DOI: 10.3389/fncel.2019.00433] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), a lifelong disorder that starts during adolescence, is the most common of genetic generalized epilepsy syndromes. JME is characterized by awakening myoclonic jerks and myoclonic-tonic-clonic (m-t-c) grand mal convulsions. Unfortunately, one third of JME patients have drug refractory m-t-c convulsions and these recur in 70-80% who attempt to stop antiepileptic drugs (AEDs). Behavioral studies documented impulsivity, but also impairment of executive functions relying on organization and feedback, which points to prefrontal lobe dysfunction. Quantitative voxel-based morphometry (VBM) revealed abnormalities of gray matter (GM) volumes in cortical (frontal and parietal) and subcortical structures (thalamus, putamen, and hippocampus). Proton magnetic resonance spectroscopy (MRS) found evidence of dysfunction of thalamic neurons. White matter (WM) integrity was disrupted in corpus callosum and frontal WM tracts. Magnetic resonance imaging (MRI) further unveiled anomalies in both GM and WM structures that were already present at the time of seizure onset. Aberrant growth trajectories of brain development occurred during the first 2 years of JME diagnosis. Because of genetic origin, disease causing variants were sought, first by positional cloning, and most recently, by next generation sequencing. To date, only six genes harboring pathogenic variants (GABRA1, GABRD, EFHC1, BRD2, CASR, and ICK) with Mendelian and complex inheritance and covering a limited proportion of the world population, are considered as major susceptibility alleles for JME. Evidence on the cellular role, developmental and cell-type expression profiles of these six diverse JME genes, point to their pathogenic variants driving the first steps of brain development when cell division, expansion, axial, and tangential migration of progenitor cells (including interneuron cortical progenitors) sculpture subtle alterations in brain networks and microcircuits during development. These alterations may explain "microdysgenesis" neuropathology, impulsivity, executive dysfunctions, EEG polyspike waves, and awakening m-t-c convulsions observed in JME patients.
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Affiliation(s)
- Maxime Gilsoul
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Thierry Grisar
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Antonio V. Delgado-Escueta
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Epilepsy Genetics/Genomics Lab, Neurology and Research Services, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Laurence de Nijs
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- School for Mental Health and Neuroscience, Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands
| | - Bernard Lakaye
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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3
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Fantin M, Garelli F, Napoli B, Forgiarini A, Gumeni S, De Martin S, Montopoli M, Vantaggiato C, Orso G. Flavonoids Regulate Lipid Droplets Biogenesis in Drosophila melanogaster. Nat Prod Commun 2019. [DOI: 10.1177/1934578x19852430] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Lipid droplets (LDs), cytosolic fat storage organelles, are emerging as major regulators of lipid metabolism, trafficking, and signaling in various cells and tissues. LDs are altered in cardiovascular and neuronal disorders, inflammation, obesity, and cancer. Flavonoids comprise different classes of molecules, characterized by a well-known antioxidant activity and a beneficial effect in several diseases. However, the cellular mechanism by which different classes of flavonoids improve health is poorly understood, in particular as far as LDs biogenesis is concerned. Here we used Drosophila melanogaster as a model system to investigate the effects of a selected group of flavonoids on larval tissues by examining LDs biogenesis. In our study, fruit flies were grown in xanthohumol-, isoquercetin-, and genistein-enriched food and larval tissues were analyzed using a LD marker. Total mRNA expression of two main enzymes (minotaur and midway) responsible for triacylglycerides synthesis was evaluated after treatments. Among the flavonoids analyzed, xanthohumol and isoquercetin resulted to be potent regulators of LDs biogenesis in a tissue-specific manner, inducing fat storage decrease in fat bodies and accumulation of LDs in nerves. Since LDs have been suggested to play a protective role against intracellular stress in nonadipocyte cells, our data support the hypothesis that some phytochemicals could act as strong modulators of LDs biogenesis in vivo. The knowledge of how different flavonoids act on lipid metabolism in different tissues can help to manage the use of phytochemicals with the aim of selectively ameliorating specific neuronal and metabolic diseases’ manifestations.
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Affiliation(s)
- Marianna Fantin
- Scientific Institute, IRCCS E. Medea, Laboratory of Molecular Biology, Bosisio Parini, Lecco, Italy
| | - Francesca Garelli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
| | - Barbara Napoli
- Scientific Institute, IRCCS E. Medea, Laboratory of Molecular Biology, Bosisio Parini, Lecco, Italy
| | - Alessia Forgiarini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
| | - Sentiljana Gumeni
- Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Greece
| | - Sara De Martin
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
| | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
| | - Chiara Vantaggiato
- Scientific Institute, IRCCS E. Medea, Laboratory of Molecular Biology, Bosisio Parini, Lecco, Italy
| | - Genny Orso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
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4
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Forgiarini A, Wang Z, D’Amore C, Jay-Smith M, Li FF, Hopkins B, Brimble MA, Pagetta A, Bersani S, De Martin S, Napoli B, Bova S, Rennison D, Orso G. Live applications of norbormide-based fluorescent probes in Drosophila melanogaster. PLoS One 2019; 14:e0211169. [PMID: 30958824 PMCID: PMC6453474 DOI: 10.1371/journal.pone.0211169] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/26/2019] [Indexed: 11/20/2022] Open
Abstract
In this study we investigated the performance of two norbormide (NRB)-derived fluorescent probes, NRBMC009 (green) and NRBZLW0047 (red), on dissected, living larvae of Drosophila, to verify their potential application in live cell imaging confocal microscopy. To this end, larval tissues were exposed to NRB probes alone or in combination with other commercial dyes or GFP-tagged protein markers. Both probes were rapidly internalized by most tissues (except the central nervous system) allowing each organ in the microscope field to be readily distinguished at low magnification. At the cellular level, the probes showed a very similar distribution (except for fat bodies), defined by loss of signal in the nucleus and plasma membrane, and a preferential localization to endoplasmic reticulum (ER) and mitochondria. They also recognized ER and mitochondrial phenotypes in the skeletal muscles of fruit fly models that had loss of function mutations in the atlastin and mitofusin genes, suggesting NRBMC009 and NRBZLW0047 as potentially useful screening tools for characterizing ER and mitochondria morphological alterations. Feeding of larvae and adult Drosophilae with the NRB-derived dyes led to staining of the gut and its epithelial cells, revealing a potential role in food intake assays. In addition, when flies were exposed to either dye over their entire life cycle no apparent functional or morphological abnormalities were detected. Rapid internalization, a bright signal, a compatibility with other available fluorescent probes and GFP-tagged protein markers, and a lack of toxicity make NRBZLW0047 and, particularly, NRBMC009 highly performing fluorescent probes for live cell microscopy studies and food intake assays in Drosophila.
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Affiliation(s)
- Alessia Forgiarini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Zifei Wang
- University of Auckland, School of Chemical Sciences, Auckland, New Zealand
| | - Claudio D’Amore
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Morgan Jay-Smith
- University of Auckland, School of Chemical Sciences, Auckland, New Zealand
| | - Freda Fan Li
- University of Auckland, School of Chemical Sciences, Auckland, New Zealand
| | | | | | - Andrea Pagetta
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Sara Bersani
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Sara De Martin
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Barbara Napoli
- Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Sergio Bova
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - David Rennison
- University of Auckland, School of Chemical Sciences, Auckland, New Zealand
| | - Genny Orso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
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Loucks CM, Park K, Walker DS, McEwan AH, Timbers TA, Ardiel EL, Grundy LJ, Li C, Johnson JL, Kennedy J, Blacque OE, Schafer W, Rankin CH, Leroux MR. EFHC1, implicated in juvenile myoclonic epilepsy, functions at the cilium and synapse to modulate dopamine signaling. eLife 2019; 8:37271. [PMID: 30810526 PMCID: PMC6392500 DOI: 10.7554/elife.37271] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 02/06/2019] [Indexed: 01/03/2023] Open
Abstract
Neurons throughout the mammalian brain possess non-motile cilia, organelles with varied functions in sensory physiology and cellular signaling. Yet, the roles of cilia in these neurons are poorly understood. To shed light into their functions, we studied EFHC1, an evolutionarily conserved protein required for motile cilia function and linked to a common form of inherited epilepsy in humans, juvenile myoclonic epilepsy (JME). We demonstrate that C. elegans EFHC-1 functions within specialized non-motile mechanosensory cilia, where it regulates neuronal activation and dopamine signaling. EFHC-1 also localizes at the synapse, where it further modulates dopamine signaling in cooperation with the orthologue of an R-type voltage-gated calcium channel. Our findings unveil a previously undescribed dual-regulation of neuronal excitability at sites of neuronal sensory input (cilium) and neuronal output (synapse). Such a distributed regulatory mechanism may be essential for establishing neuronal activation thresholds under physiological conditions, and when impaired, may represent a novel pathomechanism for epilepsy.
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Affiliation(s)
- Catrina M Loucks
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Kwangjin Park
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Denise S Walker
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Andrea H McEwan
- Djavad Mowfaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Tiffany A Timbers
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Evan L Ardiel
- Djavad Mowfaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Laura J Grundy
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Jacque-Lynne Johnson
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Julie Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - William Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Catharine H Rankin
- Djavad Mowfaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.,Department of Psychology, University of British Columbia, Vancouver, Canada
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada.,Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
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6
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Abstract
Motile and non-motile (primary) cilia are nearly ubiquitous cellular organelles. The dysfunction of cilia causes diseases known as ciliopathies. The number of reported ciliopathies (currently 35) is increasing, as is the number of established (187) and candidate (241) ciliopathy-associated genes. The characterization of ciliopathy-associated proteins and phenotypes has improved our knowledge of ciliary functions. In particular, investigating ciliopathies has helped us to understand the molecular mechanisms by which the cilium-associated basal body functions in early ciliogenesis, as well as how the transition zone functions in ciliary gating, and how intraflagellar transport enables cargo trafficking and signalling. Both basic biological and clinical studies are uncovering novel ciliopathies and the ciliary proteins involved. The assignment of these proteins to different ciliary structures, processes and ciliopathy subclasses (first order and second order) provides insights into how this versatile organelle is built, compartmentalized and functions in diverse ways that are essential for human health.
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7
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Raju PK, Satishchandra P, Nayak S, Iyer V, Sinha S, Anand A. Microtubule-associated defects caused by EFHC1
mutations in juvenile myoclonic epilepsy. Hum Mutat 2017; 38:816-826. [DOI: 10.1002/humu.23221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/21/2017] [Accepted: 03/21/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Praveen K Raju
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
| | | | - Sourav Nayak
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
| | - Vishwanathan Iyer
- Department of Neurology; National Institute of Mental Health and Neurosciences; Bangalore Karnataka India
| | - Sanjib Sinha
- Department of Neurology; National Institute of Mental Health and Neurosciences; Bangalore Karnataka India
| | - Anuranjan Anand
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
- Neuroscience Unit; Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
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EFHC1 variants in juvenile myoclonic epilepsy: reanalysis according to NHGRI and ACMG guidelines for assigning disease causality. Genet Med 2016; 19:144-156. [PMID: 27467453 DOI: 10.1038/gim.2016.86] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/09/2016] [Indexed: 12/12/2022] Open
Abstract
PURPOSE EFHC1 variants are the most common mutations in inherited myoclonic and grand mal clonic-tonic-clonic (CTC) convulsions of juvenile myoclonic epilepsy (JME). We reanalyzed 54 EFHC1 variants associated with epilepsy from 17 cohorts based on National Human Genome Research Institute (NHGRI) and American College of Medical Genetics and Genomics (ACMG) guidelines for interpretation of sequence variants. METHODS We calculated Bayesian LOD scores for variants in coinheritance, unconditional exact tests and odds ratios (OR) in case-control associations, allele frequencies in genome databases, and predictions for conservation/pathogenicity. We reviewed whether variants damage EFHC1 functions, whether efhc1-/- KO mice recapitulate CTC convulsions and "microdysgenesis" neuropathology, and whether supernumerary synaptic and dendritic phenotypes can be rescued in the fly model when EFHC1 is overexpressed. We rated strengths of evidence and applied ACMG combinatorial criteria for classifying variants. RESULTS Nine variants were classified as "pathogenic," 14 as "likely pathogenic," 9 as "benign," and 2 as "likely benign." Twenty variants of unknown significance had an insufficient number of ancestry-matched controls, but ORs exceeded 5 when compared with racial/ethnic-matched Exome Aggregation Consortium (ExAC) controls. CONCLUSIONS NHGRI gene-level evidence and variant-level evidence establish EFHC1 as the first non-ion channel microtubule-associated protein whose mutations disturb R-type VDCC and TRPM2 calcium currents in overgrown synapses and dendrites within abnormally migrated dislocated neurons, thus explaining CTC convulsions and "microdysgenesis" neuropathology of JME.Genet Med 19 2, 144-156.
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9
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Zhao Y, Shi J, Winey M, Klymkowsky MW. Identifying domains of EFHC1 involved in ciliary localization, ciliogenesis, and the regulation of Wnt signaling. Dev Biol 2016; 411:257-265. [PMID: 26783883 DOI: 10.1016/j.ydbio.2016.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/16/2015] [Accepted: 01/07/2016] [Indexed: 12/24/2022]
Abstract
EFHC1 encodes a ciliary protein that has been linked to Juvenile Myoclonic Epilepsy. In ectodermal explants, derived from Xenopus laevis embryos, the morpholino-mediated down-regulation of EFHC1b inhibited multiciliated cell formation. In those ciliated cells that did form, axoneme but not basal body formation was inhibited. EFHC1b morphant embryos displayed defects in central nervous system (CNS) and neural crest patterning that were rescued by a EFHC1b-GFP chimera. EFHC1b-GFP localized to ciliary axonemes in epidermal, gastrocoele roof plate, and neural tube cells. In X. laevis there is a link between Wnt signaling and multiciliated cell formation. While down-regulation of EFHC1b led to a ~2-fold increase in the activity of the β-catenin/Wnt-responsive TOPFLASH reporter, EFHC1b-GFP did not inhibit β-catenin activation of TOPFLASH. Wnt8a RNA levels were increased in EFHC1b morphant ectodermal explants and intact embryos, analyzed prior to the on-set of ciliogenesis. Rescue of the EFHC1b MO's ciliary axonemal phenotypes required the entire protein; in contrast, the EFHC1b morpholino's Wnt8a, CNS, and neural crest phenotypes were rescued by a truncated form of EFHC1b. The EFHC1b morpholino's Wnt8a phenotype was also rescued by the injection of RNAs encoding secreted Wnt inhibitors, suggesting that these phenotypes are due to effects on Wnt signaling, rather than the loss of cilia, an observation of potential relevance to understanding EFHC1's role in human neural development.
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Affiliation(s)
- Ying Zhao
- Molecular, Cellular & Developmental Biology, University of Colorado Boulder Boulder, Colorado 80309-0347, USA
| | - Jianli Shi
- Molecular, Cellular & Developmental Biology, University of Colorado Boulder Boulder, Colorado 80309-0347, USA
| | - Mark Winey
- Molecular, Cellular & Developmental Biology, University of Colorado Boulder Boulder, Colorado 80309-0347, USA
| | - Michael W Klymkowsky
- Molecular, Cellular & Developmental Biology, University of Colorado Boulder Boulder, Colorado 80309-0347, USA.
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10
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Sapio MR, Vessaz M, Thomas P, Genton P, Fricker LD, Salzmann A. Novel carboxypeptidase A6 (CPA6) mutations identified in patients with juvenile myoclonic and generalized epilepsy. PLoS One 2015; 10:e0123180. [PMID: 25875328 PMCID: PMC4395397 DOI: 10.1371/journal.pone.0123180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 02/17/2015] [Indexed: 01/12/2023] Open
Abstract
Carboxypeptidase A6 (CPA6) is a peptidase that removes C-terminal hydrophobic amino acids from peptides and proteins. The CPA6 gene is expressed in the brains of humans and animals, with high levels of expression during development. It is translated with a prodomain (as proCPA6), which is removed before secretion. The active form of CPA6 binds tightly to the extracellular matrix (ECM) where it is thought to function in the processing of peptides and proteins. Mutations in the CPA6 gene have been identified in patients with temporal lobe epilepsy and febrile seizures. In the present study, we screened for CPA6 mutations in patients with juvenile myoclonic epilepsy and identified two novel missense mutations: Arg36His and Asn271Ser. Patients harboring these mutations also presented with generalized epilepsy. Neither of the novel mutations was found in a control population. Asn271 is highly conserved in CPA6 and other related metallocarboxypeptidases. Arg36 is present in the prodomain and is not highly conserved. To assess structural consequences of the amino acid substitutions, both mutants were modeled within the predicted structure of the enzyme. To examine the effects of these mutations on enzyme expression and activity, we expressed the mutated enzymes in human embryonic kidney 293T cells. These analyses revealed that Asn271Ser abolished enzymatic activity, while Arg36His led to a ~50% reduction in CPA6 levels in the ECM. Pulse-chase using radio-labeled amino acids was performed to follow secretion. Newly-synthesized CPA6 appeared in the ECM with peak levels between 2-8 hours. There was no major difference in time course between wild-type and mutant forms, although the amount of radiolabeled CPA6 in the ECM was lower for the mutants. Our experiments demonstrate that these mutations in CPA6 are deleterious and provide further evidence for the involvement of CPA6 mutations in the predisposition for several types of epilepsy.
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Affiliation(s)
- Matthew R. Sapio
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Monique Vessaz
- Department of Genetic Medicine and Laboratory, University Hospitals of Geneva, Geneva, Switzerland
| | - Pierre Thomas
- Department of Neurology, University Hospital, Nice, France
| | - Pierre Genton
- Centre Saint Paul, Hôpital Henri Gastaut, Marseille, France
| | - Lloyd D. Fricker
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
- * E-mail: (LDF); (AS)
| | - Annick Salzmann
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
- * E-mail: (LDF); (AS)
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de Nijs L, Wolkoff N, Grisar T, Lakaye B. Juvenile myoclonic epilepsy as a possible neurodevelopmental disease: role of EFHC1 or Myoclonin1. Epilepsy Behav 2013; 28 Suppl 1:S58-60. [PMID: 23756481 DOI: 10.1016/j.yebeh.2012.06.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 11/18/2022]
Abstract
Juvenile Myoclonic Epilepsy (JME) accounts for almost 12% of all epilepsies and is one of the most frequent forms of genetic generalized epilepsies. Genetic studies have revealed that mutations in EFHC1 (EF-hand containing one) account for 3 to 9% of all cases around the world. This gene encodes a protein that is not an ion channel, and several studies have tried to find its cellular role. In this article, we review the various functions that have been proposed for this protein. Interestingly, all of them could affect brain development at different steps, suggesting that the developmental assembly of neural circuits may play a prominent role in JME.
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de Nijs L, Wolkoff N, Coumans B, Delgado-Escueta AV, Grisar T, Lakaye B. Mutations of EFHC1, linked to juvenile myoclonic epilepsy, disrupt radial and tangential migrations during brain development. Hum Mol Genet 2012; 21:5106-17. [PMID: 22926142 DOI: 10.1093/hmg/dds356] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Heterozygous mutations in Myoclonin1/EFHC1 cause juvenile myoclonic epilepsy (JME), the most common form of genetic generalized epilepsies, while homozygous F229L mutation is associated with primary intractable epilepsy in infancy. Heterozygous mutations in adolescent JME patients produce subtle malformations of cortical and subcortical architecture, whereas homozygous F229L mutation in infancy induces severe brain pathology and death. However, the underlying pathological mechanisms for these observations remain unknown. We had previously demonstrated that EFHC1 is a microtubule-associated protein (MAP) involved in cell division and radial migration during cerebral corticogenesis. Here, we show that JME mutations, including F229L, do not alter the ability of EFHC1 to colocalize with the centrosome and the mitotic spindle, but act in a dominant-negative manner to impair mitotic spindle organization. We also found that mutants EFHC1 expression disrupted radial and tangential migration by affecting the morphology of radial glia and migrating neurons. These results show how Myoclonin1/EFHC1 mutations disrupt brain development and potentially produce structural brain abnormalities on which epileptogenesis is established.
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Jara-Prado A, Martínez-Juárez IE, Ochoa A, González VM, Fernández-González-Aragón MDC, López-Ruiz M, Medina MT, Bailey JN, Delgado-Escueta AV, Alonso ME. Novel Myoclonin1/EFHC1 mutations in Mexican patients with juvenile myoclonic epilepsy. Seizure 2012; 21:550-4. [PMID: 22727576 DOI: 10.1016/j.seizure.2012.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/28/2012] [Accepted: 05/29/2012] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The purpose of this study was to identify the prevalence of mutations in the Myoclonin1/EFHC1 gene in Mexican patients with juvenile myoclonic epilepsy (JME). METHOD We studied forty-one patients at the National Institute of Neurology and Neurosurgery in Mexico City and 100 healthy controls. DNA was extracted from the peripheral venous blood of all participants. The exons of EFHC1 were then amplified and sequenced. RESULTS We found three new putative mutations, all of which were heterozygous missense mutations located in exon 3. The first identified mutation, 352C>T, produces a R118C change in the protein and cosegregated in the patient's affected father and brother. The second identified mutation, 544C>T, produces a R182L change in the protein and was found in the patient's asymptomatic father. The third identified mutation, 458>A, produces a R153Q change in the protein and was also found in the patient's father. These mutations were not found in controls. CONCLUSIONS The frequency of Myoclonin1/EFHC1 mutations in our sample is 7.3%. Thus, we conclude that mutations in the Myoclonin1/EFHC1 gene are an important cause of JME in Mexican patients.
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Affiliation(s)
- Aurelio Jara-Prado
- Neurogenetics and Molecular Biology Department, National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur 3877, Col. La Fama, Tlalpan, México D.F. 14269, Mexico.
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Berger I, Dor T, Halvardson J, Edvardson S, Shaag A, Feuk L, Elpeleg O. Intractable epilepsy of infancy due to homozygous mutation in the EFHC1 gene. Epilepsia 2012; 53:1436-40. [DOI: 10.1111/j.1528-1167.2012.03536.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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