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Quinn S, Zhang N, Fenton TA, Brusel M, Muruganandam P, Peleg Y, Giladi M, Haitin Y, Lerche H, Bassan H, Liu Y, Ben-Shalom R, Rubinstein M. Complex biophysical changes and reduced neuronal firing in an SCN8A variant associated with developmental delay and epilepsy. Biochim Biophys Acta Mol Basis Dis 2024:167127. [PMID: 38519006 DOI: 10.1016/j.bbadis.2024.167127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 03/24/2024]
Abstract
Mutations in the SCN8A gene, encoding the voltage-gated sodium channel NaV1.6, are associated with a range of neurodevelopmental syndromes. The p.(Gly1625Arg) (G1625R) mutation was identified in a patient diagnosed with Developmental epileptic encephalopathy (DEE). While most of the characterized DEE-associated SCN8A mutations were shown to cause a gain-of-channel function, we show that the G1625R variant, positioned within the S4 segment of domain IV, results in complex effects. Voltage-clamp analyses of NaV1.6G1625R demonstrated a mixture of gain- and loss-of-function properties, including reduced current amplitudes, increased time constant of fast voltage-dependent inactivation, a depolarizing shift in the voltage dependence of activation and inactivation, and increased channel availability with high-frequency repeated depolarization. Current clamp analyses in transfected cultured neurons revealed that these biophysical properties caused a marked reduction in the number of action potentials when firing was driven by the transfected mutant NaV1.6. Accordingly, computational modeling of mature cortical neurons demonstrated a mild decrease in neuronal firing when mimicking the patients' heterozygous SCN8A expression. Structural modeling of NaV1.6G1625R suggested the formation of a cation-π interaction between R1625 and F1588 within domain IV. Double-mutant cycle analysis revealed that this interaction affects the voltage dependence of inactivation in NaV1.6G1625R. Together, our studies demonstrate that the G1625R variant leads to a complex combination of gain and loss of function biophysical changes that result in an overall mild reduction in neuronal firing, related to the perturbed interaction network within the voltage sensor domain, necessitating personalized multi-tiered analysis for SCN8A mutations for optimal treatment selection.
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Affiliation(s)
- Shir Quinn
- Goldschleger Eye Research Institute, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nan Zhang
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Timothy A Fenton
- Neurology Department, MIND Institute, University of California, Davis, Sacramento, CA, United States
| | - Marina Brusel
- Goldschleger Eye Research Institute, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Preethi Muruganandam
- Neurology Department, MIND Institute, University of California, Davis, Sacramento, CA, United States
| | - Yoav Peleg
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Moshe Giladi
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Yoni Haitin
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Haim Bassan
- Pediatric Neurology and Development Center, Shamir Medical Center (Assaf Harofeh), Zerifin, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuanyuan Liu
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Roy Ben-Shalom
- Neurology Department, MIND Institute, University of California, Davis, Sacramento, CA, United States
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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Fadila S, Beucher B, Dopeso-Reyes IG, Mavashov A, Brusel M, Anderson K, Ismeurt C, Goldberg EM, Ricobaraza A, Hernandez-Alcoceba R, Kremer EJ, Rubinstein M. Viral vector-mediated expression of NaV1.1, after seizure onset, reduces epilepsy in mice with Dravet syndrome. J Clin Invest 2023:159316. [PMID: 37192002 DOI: 10.1172/jci159316] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
Dravet syndrome (DS), an intractable childhood epileptic encephalopathy with a high fatality rate, is typically caused by loss-of-function mutations in one allele of SCN1A, which encodes NaV1.1, a 250-kDa voltage-gated sodium channel. In contrast to other epilepsies, pharmaceutical treatment for DS is limited. Here, we demonstrate that viral vector-mediated delivery of a codon-modified SCN1A open reading frame into the brain improves DS comorbidities in juvenile and adolescent DS mice (Scn1aA1783V/WT). Notably, bilateral vector injections into the hippocampus and/or the thalamus of DS mice increased survival, reduced the occurrence of epileptic spikes, provided protection from thermally-induced seizures, corrected background electrocorticography activity and behavioral deficits, and restored hippocampal inhibition. Together, our results provide a proof-of-concept for the potential of SCN1A delivery as a therapeutic approach for infants and adolescents with DS-associated comorbidities.
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Affiliation(s)
- Saja Fadila
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Anat Mavashov
- Sagol School of Neuroscience, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Karen Anderson
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Caroline Ismeurt
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
| | - Ethan M Goldberg
- University of Pennsylvania, Perelman School of Medicine, Philadelphia, United States of America
| | - Ana Ricobaraza
- Gene Therapy and Regulation of Gene Expression Program, CIMA University of Navarra, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- Gene Therapy and Regulation of Gene Expression Program, CIMA University of Navarra, Pamplona, Spain
| | - Eric J Kremer
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
| | - Moran Rubinstein
- Human Molecular Genetics, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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3
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Quinn S, Brusel M, Ovadia M, Rubinstein M. Acute effect of antiseizure drugs on background oscillations in Scn1aA1783V Dravet syndrome mouse model. Front Pharmacol 2023; 14:1118216. [PMID: 37021051 PMCID: PMC10067575 DOI: 10.3389/fphar.2023.1118216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/07/2023] [Indexed: 03/22/2023] Open
Abstract
Dravet syndrome (Dravet) is a rare and severe form of developmental epileptic encephalopathy. Antiseizure medications (ASMs) for Dravet patients include valproic acid (VA) or clobazam (CLB), with or without stiripentol (STP), while sodium channel blockers like carbamazepine (CBZ) or lamotrigine (LTG) are contraindicated. In addition to their effect on epileptic phenotypes, ASMs were shown to modify the properties of background neuronal activity. Nevertheless, little is known about these background properties alterations in Dravet. Here, utilizing Dravet mice (DS, Scn1aA1783V/WT), we tested the acute effect of several ASMs on background electrocorticography (ECoG) activity and frequency of interictal spikes. Compared to wild-type mice, background ECoG activity in DS mice had lower power and reduced phase coherence, which was not corrected by any of the tested ASMs. However, acute administration of Dravet-recommended drugs, VA, CLB, or a combination of CLB + STP, caused, in most mice, a reduction in the frequency of interictal spikes, alongside an increase in the relative contribution of the beta frequency band. Conversely, CBZ and LTG increased the frequency of interictal spikes, with no effect on background spectral properties. Moreover, we uncovered a correlation between the reduction in interictal spike frequency, the drug-induced effect on the power of background activity, and a spectral shift toward higher frequency bands. Together, these data provide a comprehensive analysis of the effect of selected ASMs on the properties of background neuronal oscillations, and highlight a possible correlation between their effect on epilepsy and background activity.
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Affiliation(s)
- Shir Quinn
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mor Ovadia
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
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Mavashov A, Brusel M, Liu J, Woytowicz V, Bae H, Chen YH, Dani VS, Cardenal-Muñoz E, Spinosa V, Aibar JÁ, Rubinstein M. Heat-induced seizures, premature mortality, and hyperactivity in a novel Scn1a nonsense model for Dravet syndrome. Front Cell Neurosci 2023; 17:1149391. [PMID: 37206664 PMCID: PMC10191256 DOI: 10.3389/fncel.2023.1149391] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/05/2023] [Indexed: 05/21/2023] Open
Abstract
Dravet syndrome (Dravet) is a severe congenital developmental genetic epilepsy caused by de novo mutations in the SCN1A gene. Nonsense mutations are found in ∼20% of the patients, and the R613X mutation was identified in multiple patients. Here we characterized the epileptic and non-epileptic phenotypes of a novel preclinical Dravet mouse model harboring the R613X nonsense Scn1a mutation. Scn1aWT/R613X mice, on a mixed C57BL/6J:129S1/SvImJ background, exhibited spontaneous seizures, susceptibility to heat-induced seizures, and premature mortality, recapitulating the core epileptic phenotypes of Dravet. In addition, these mice, available as an open-access model, demonstrated increased locomotor activity in the open-field test, modeling some non-epileptic Dravet-associated phenotypes. Conversely, Scn1aWT/R613X mice, on the pure 129S1/SvImJ background, had a normal life span and were easy to breed. Homozygous Scn1aR613X/R613X mice (pure 129S1/SvImJ background) died before P16. Our molecular analyses of hippocampal and cortical expression demonstrated that the premature stop codon induced by the R613X mutation reduced Scn1a mRNA and NaV1.1 protein levels to ∼50% in heterozygous Scn1aWT/R613X mice (on either genetic background), with marginal expression in homozygous Scn1aR613X/R613X mice. Together, we introduce a novel Dravet model carrying the R613X Scn1a nonsense mutation that can be used to study the molecular and neuronal basis of Dravet, as well as the development of new therapies associated with SCN1A nonsense mutations in Dravet.
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Affiliation(s)
- Anat Mavashov
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jiaxing Liu
- Tevard Biosciences, Cambridge, MA, United States
| | | | - Haneui Bae
- Tevard Biosciences, Cambridge, MA, United States
| | | | | | | | | | | | - Moran Rubinstein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
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Almog Y, Mavashov A, Brusel M, Rubinstein M. Functional Investigation of a Neuronal Microcircuit in the CA1 Area of the Hippocampus Reveals Synaptic Dysfunction in Dravet Syndrome Mice. Front Mol Neurosci 2022; 15:823640. [PMID: 35370551 PMCID: PMC8966673 DOI: 10.3389/fnmol.2022.823640] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Dravet syndrome is severe childhood-onset epilepsy, caused by loss of function mutations in the SCN1A gene, encoding for the voltage-gated sodium channel NaV1.1. The leading hypothesis is that Dravet is caused by selective reduction in the excitability of inhibitory neurons, due to hampered activity of NaV1.1 channels in these cells. However, these initial neuronal changes can lead to further network alterations. Here, focusing on the CA1 microcircuit in hippocampal brain slices of Dravet syndrome (DS, Scn1aA1783V/WT) and wild-type (WT) mice, we examined the functional response to the application of Hm1a, a specific NaV1.1 activator, in CA1 stratum-oriens (SO) interneurons and CA1 pyramidal excitatory neurons. DS SO interneurons demonstrated reduced firing and depolarized threshold for action potential (AP), indicating impaired activity. Nevertheless, Hm1a induced a similar AP threshold hyperpolarization in WT and DS interneurons. Conversely, a smaller effect of Hm1a was observed in CA1 pyramidal neurons of DS mice. In these excitatory cells, Hm1a application resulted in WT-specific AP threshold hyperpolarization and increased firing probability, with no effect on DS neurons. Additionally, when the firing of SO interneurons was triggered by CA3 stimulation and relayed via activation of CA1 excitatory neurons, the firing probability was similar in WT and DS interneurons, also featuring a comparable increase in the firing probability following Hm1a application. Interestingly, a similar functional response to Hm1a was observed in a second DS mouse model, harboring the nonsense Scn1aR613X mutation. Furthermore, we show homeostatic synaptic alterations in both CA1 pyramidal neurons and SO interneurons, consistent with reduced excitation and inhibition onto CA1 pyramidal neurons and increased release probability in the CA1-SO synapse. Together, these results suggest global neuronal alterations within the CA1 microcircuit extending beyond the direct impact of NaV1.1 dysfunction.
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Affiliation(s)
- Yael Almog
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Anat Mavashov
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
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6
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Almog Y, Fadila S, Brusel M, Mavashov A, Anderson K, Rubinstein M. Developmental alterations in firing properties of hippocampal CA1 inhibitory and excitatory neurons in a mouse model of Dravet syndrome. Neurobiol Dis 2020; 148:105209. [PMID: 33271326 DOI: 10.1016/j.nbd.2020.105209] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 11/07/2020] [Accepted: 11/24/2020] [Indexed: 11/17/2022] Open
Abstract
Dravet syndrome (Dravet) is a rare, severe childhood-onset epilepsy, caused by heterozygous de novo mutations in the SCN1A gene, encoding for the alpha subunit of the voltage-gated sodium channel, NaV1.1. The neuronal basis of Dravet is debated, with evidence favoring reduced function of inhibitory neurons, that might be transient, or enhanced activity of excitatory cells. Here, we utilized Dravet mice to trace developmental changes in the hippocampal CA1 circuit, examining the properties of CA1 horizontal stratum-oriens (SO) interneurons and pyramidal neurons, through the pre-epileptic, severe and stabilization stages of Dravet. Our data indicate that reduced function of SO interneurons persists from the pre-epileptic through the stabilization stages, with the greatest functional impairment observed during the severe stage. In contrast, opposing changes were detected in CA1 excitatory neurons, with a transient increase in their excitability during the pre-epileptic stage, followed by reduced excitability at the severe stage. Interestingly, alterations in the function of both inhibitory and excitatory neurons were more pronounced when the firing was evoked by synaptic stimulation, implying that loss of function of NaV1.1 may also affect somatodendritic functions. These results suggest a complex pathophysiological mechanism and indicate that the developmental trajectory of this disease is governed by reciprocal functional changes in both excitatory and inhibitory neurons.
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Affiliation(s)
- Yael Almog
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Saja Fadila
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anat Mavashov
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Karen Anderson
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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7
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Barnes AM, Ashok A, Makareeva EN, Brusel M, Cabral WA, Weis M, Moali C, Bettler E, Eyre DR, Cassella JP, Leikin S, Hulmes DJS, Kessler E, Marini JC. COL1A1 C-propeptide mutations cause ER mislocalization of procollagen and impair C-terminal procollagen processing. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2210-2223. [PMID: 31055083 DOI: 10.1016/j.bbadis.2019.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/15/2019] [Accepted: 04/30/2019] [Indexed: 10/26/2022]
Abstract
Mutations in the type I procollagen C-propeptide occur in ~6.5% of Osteogenesis Imperfecta (OI) patients. They are of special interest because this region of procollagen is involved in α chain selection and folding, but is processed prior to fibril assembly and is absent in mature collagen fibrils in tissue. We investigated the consequences of seven COL1A1 C-propeptide mutations for collagen biochemistry in comparison to three probands with classical glycine substitutions in the collagen helix near the C-propeptide and a normal control. Procollagens with C-propeptide defects showed the expected delayed chain incorporation, slow folding and overmodification. Immunofluorescence microscopy indicated that procollagen with C-propeptide defects was mislocalized to the ER lumen, in contrast to the ER membrane localization of normal procollagen and procollagen with helical substitutions. Notably, pericellular processing of procollagen with C-propeptide mutations was defective, with accumulation of pC-collagen and/or reduced production of mature collagen. In vitro cleavage assays with BMP-1 ± PCPE-1 confirmed impaired C-propeptide processing of procollagens containing mutant proα1(I) chains. Overmodified collagens were incorporated into the matrix in culture. Dermal fibrils showed alterations in average diameter and diameter variability and bone fibrils were disorganized. Altered ER-localization and reduced pericellular processing of defective C-propeptides are expected to contribute to abnormal osteoblast differentiation and matrix function, respectively.
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Affiliation(s)
- Aileen M Barnes
- Section of Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, MD, United States of America
| | - Aarthi Ashok
- Section of Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, MD, United States of America; University of Toronto Scarborough, Toronto, ON, Canada
| | - Elena N Makareeva
- Section on Physical Biochemistry, NICHD, NIH, Bethesda, MD, United States of America
| | - Marina Brusel
- Goldschleger Eye Research Institute, Tel Aviv University Sackler Faculty of Medicine, Tel-Hashomer, Israel
| | - Wayne A Cabral
- Section of Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, MD, United States of America; Molecular Genetics Section, Medical Genomics and Metabolic Genetics Branch, NHGRI, NIH, Bethesda, MD, United States of America
| | - MaryAnn Weis
- Orthopaedic Research Labs, University of Washington, Seattle, WA, United States of America
| | - Catherine Moali
- Tissue Biology and Therapeutic Engineering Unit, UMR5305, CNRS/University of Lyon, Lyon, France
| | - Emmanuel Bettler
- Tissue Biology and Therapeutic Engineering Unit, UMR5305, CNRS/University of Lyon, Lyon, France
| | - David R Eyre
- Orthopaedic Research Labs, University of Washington, Seattle, WA, United States of America
| | - John P Cassella
- Department of Forensic and Crime Science, Staffordshire University, Staffordshire, UK
| | - Sergey Leikin
- Section on Physical Biochemistry, NICHD, NIH, Bethesda, MD, United States of America
| | - David J S Hulmes
- Tissue Biology and Therapeutic Engineering Unit, UMR5305, CNRS/University of Lyon, Lyon, France
| | - Efrat Kessler
- Goldschleger Eye Research Institute, Tel Aviv University Sackler Faculty of Medicine, Tel-Hashomer, Israel
| | - Joan C Marini
- Section of Heritable Disorders of Bone and Extracellular Matrix, NICHD, NIH, Bethesda, MD, United States of America.
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Nissenkorn A, Almog Y, Adler I, Safrin M, Brusel M, Marom M, Bercovich S, Yakubovich D, Tzadok M, Ben-Zeev B, Rubinstein M. In vivo, in vitro and in silico correlations of four de novo SCN1A missense mutations. PLoS One 2019; 14:e0211901. [PMID: 30735520 PMCID: PMC6368302 DOI: 10.1371/journal.pone.0211901] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/22/2019] [Indexed: 12/31/2022] Open
Abstract
Mutations in the SCN1A gene, which encodes for the voltage-gated sodium channel NaV1.1, cause Dravet syndrome, a severe developmental and epileptic encephalopathy. Genetic testing of this gene is recommended early in life. However, predicting the outcome of de novo missense SCN1A mutations is difficult, since milder epileptic syndromes may also be associated. In this study, we correlated clinical severity with functional in vitro electrophysiological testing of channel activity and bioinformatics prediction of damaging mutational effects. Three patients, bearing the mutations p.Gly177Ala, p.Ser259Arg and p.Glu1923Arg, showed frequent intractable seizures that had started early in life, with cognitive and behavioral deterioration, consistent with classical Dravet phenotypes. These mutations failed to produce measurable sodium currents in a mammalian expression system, indicating complete loss of channel function. A fourth patient, who harbored the mutation p.Met1267Ile, though presenting with seizures early in life, showed lower seizure burden and higher cognitive function, matching borderland Dravet phenotypes. In correlation with this, functional analysis demonstrated the presence of sodium currents, but with partial loss of function. In contrast, six bioinformatics tools for predicting mutational pathogenicity suggested similar impact for all mutations. Likewise, homology modeling of the secondary and tertiary structures failed to reveal misfolding. In conclusion, functional studies using patch clamp are suggested as a prognostic tool, whereby detectable currents imply milder phenotypes and absence of currents indicate an unfavorable prognosis. Future development of automated patch clamp systems will facilitate the inclusion of such functional testing as part of personalized patient diagnostic schemes.
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Affiliation(s)
- Andreea Nissenkorn
- Service for Rare Disorders, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
- Pediatric Neurology Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Almog
- Goldschleger Eye Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Inbar Adler
- Goldschleger Eye Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Mary Safrin
- Goldschleger Eye Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Milit Marom
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shayel Bercovich
- The Arrow Project, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
| | - Daniel Yakubovich
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Neonatal Intensive Care, Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
| | - Michal Tzadok
- Pediatric Neurology Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Bruria Ben-Zeev
- Pediatric Neurology Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Tel HaShomer, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- The Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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9
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Markovits N, Bendersky A, Loebstein R, Brusel M, Kessler E, Bank I. Anti-fibrotic characteristics of Vγ9+ γδ T cells in systemic sclerosis. Clin Exp Rheumatol 2016; 34 Suppl 100:23-29. [PMID: 26886502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVES γδ T cells of the Vγ9Vδ2 subtype secrete anti-fibrotic cytokines upon isopentenyl pyrophosphate (IPP) stimulation. In this study, we sought to compare IPP and Zoledronate, an up-regulator of IPP, effects on proliferation and cytokine secretion of Vγ9+ T cells from systemic sclerosis (SSc) patients and healthy controls (HCs). We also examined the effect of IPP-triggered peripheral blood mononuclear cells (PBMC) on fibroblast procolla- gen secretion. METHODS PBMC from SSc patients and HCs were stimulated by increasing concentrations of Zoledronate, with or without IPP, and Vγ9+ T cell percentages were calculated using FACScan analysis. Subsequently, PBMC were cultured with IPP or toxic shock syndrome toxin-1 (TSST-1), and contents of the anti-fibrotic cytokines tumour necrosis factor (TNF)-α and interferon (IFN)-γ were measured by ELISA kits. Finally, supernatants of IPP-triggered Vγ9+ T cells from SSc patients were added to fibroblast cultures, and relative intensities of procollagen α1 chains were determined by densinometry. RESULTS Higher concentrations of Zoledronate were required for maximal proliferation of Vγ9+ T cells in 9 SSc patients compared to 9 HCs, irrespective of exogenous IPP. When compared to stimulation by TSST-1, a non-Vγ9+ selective reagent, secretion of the anti-fibrotic cytokines TNF-α and IFN-γ in response to IPP was relatively diminished in SSc but not in HCs. Reduction of procollagen secretion by fibroblasts cultured with supernatants of IPP-stimulated PBMC was observed only in some SSc patients. CONCLUSIONS Activated Vγ9+ T cells could act as anti-fibrotic mediators in SSc, although decreased responsiveness to IPP may play a role in the pathological fibrosis of this disease.
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MESH Headings
- Case-Control Studies
- Cell Proliferation
- Cells, Cultured
- Collagen Type I/metabolism
- Diphosphonates/pharmacology
- Dose-Response Relationship, Drug
- Fibroblasts/immunology
- Fibroblasts/metabolism
- Fibrosis
- Hemiterpenes/pharmacology
- Humans
- Imidazoles/pharmacology
- Interferon-gamma/immunology
- Interferon-gamma/metabolism
- Lymphocyte Activation/drug effects
- Organophosphorus Compounds/pharmacology
- Phenotype
- Procollagen/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Scleroderma, Systemic/immunology
- Scleroderma, Systemic/metabolism
- Scleroderma, Systemic/pathology
- Signal Transduction
- T-Lymphocyte Subsets/drug effects
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Tumor Necrosis Factor-alpha/immunology
- Tumor Necrosis Factor-alpha/metabolism
- Zoledronic Acid
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Affiliation(s)
- Noa Markovits
- Department of Medicine A, Chaim Sheba Medical Center, Tel Hashomer; and Institute of Clinical Pharmacology, Sheba Medical Center, Tel Hashomer, Israel.
| | - Anna Bendersky
- Laboratory for Immunoregulation, Chaim Sheba Medical Center, Tel Hashomer; and Sackler School of Medicine, Tel Aviv University, Israel
| | - Ronen Loebstein
- Institute of Clinical Pharmacology, Sheba Medical Center, Tel Hashomer; and Sackler School of Medicine, Tel Aviv University, Israel
| | - Marina Brusel
- Sackler School of Medicine, Tel Aviv University; and Maurice & Gabriela Goldschleger Eye Research Institute, Sheba Medical Center, Tel Hashomer, Israel
| | - Efrat Kessler
- Sackler School of Medicine, Tel Aviv University; and Maurice & Gabriela Goldschleger Eye Research Institute, Sheba Medical Center, Tel Hashomer, Israel
| | - Ilan Bank
- Laboratory for Immunoregulation, Chaim Sheba Medical Center, Tel Hashomer; Department of Medicine F, Chaim Sheba Medical Center, Tel Hashomer; and Sackler School of Medicine, Tel Aviv University, Israel.
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10
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Lindahl K, Barnes AM, Fratzl-Zelman N, Whyte MP, Hefferan TE, Makareeva E, Brusel M, Yaszemski MJ, Rubin CJ, Kindmark A, Roschger P, Klaushofer K, McAlister WH, Mumm S, Leikin S, Kessler E, Boskey AL, Ljunggren O, Marini JC. COL1 C-propeptide cleavage site mutations cause high bone mass osteogenesis imperfecta. Hum Mutat 2011; 32:598-609. [PMID: 21344539 DOI: 10.1002/humu.21475] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 01/31/2011] [Indexed: 01/23/2023]
Abstract
Osteogenesis imperfecta (OI) is most often caused by mutations in the type I procollagen genes (COL1A1/COL1A2). We identified two children with substitutions in the type I procollagen C-propeptide cleavage site, which disrupt a unique processing step in collagen maturation and define a novel phenotype within OI. The patients have mild OI caused by mutations in COL1A1 (Patient 1: p.Asp1219Asn) or COL1A2 (Patient 2: p.Ala1119Thr), respectively. Patient 1 L1-L4 DXA Z-score was +3.9 and pQCT vBMD was+3.1; Patient 2 had L1-L4 DXA Z-score of 0.0 and pQCT vBMD of -1.8. Patient BMD contrasts with radiographic osteopenia and histomorphometry without osteosclerosis. Mutant procollagen processing is impaired in pericellular and in vitro assays. Patient dermal collagen fibrils have irregular borders. Incorporation of pC-collagen into matrix leads to increased bone mineralization. FTIR imaging confirms elevated mineral/matrix ratios in both patients, along with increased collagen maturation in trabecular bone, compared to normal or OI controls. Bone mineralization density distribution revealed a marked shift toward increased mineralization density for both patients. Patient 1 has areas of higher and lower bone mineralization than controls; Patient 2's bone matrix has a mineral content exceeding even classical OI bone. These patients define a new phenotype of high BMD OI and demonstrate that procollagen C-propeptide cleavage is crucial to normal bone mineralization.
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Affiliation(s)
- Katarina Lindahl
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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11
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Kessler E, Fichard A, Chanut-Delalande H, Brusel M, Ruggiero F. Bone morphogenetic protein-1 (BMP-1) mediates C-terminal processing of procollagen V homotrimer. J Biol Chem 2001; 276:27051-7. [PMID: 11358968 DOI: 10.1074/jbc.m102921200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The processing of the fibrillar procollagen precursors to mature collagens is an essential requirement for fibril formation. The enzymes involved in these events are known as the procollagen N and C proteinases. The latter, which cleaves the C-propeptides of the fibrillar procollagens I-III, is identical to the previously described bone morphogenetic protein-1 (BMP-1). Surprisingly, unlike the other fibrillar collagens, the processing of the C-propeptide domain of the procollagen V homotrimer was found to be mediated by furin rather than BMP-1. However, the presence of putative BMP-1 cleavage sites in the alpha1(V) C-propeptide sequence prompted us to reconsider the procollagen V C-propeptide cleavage by BMP-1. Using a recombinant system to produce substantial amounts of the proalpha1(V) homotrimer, we have previously shown that the C-propeptide is spontaneously released in the culture medium. The trimeric C-propeptide fragment, resulting from the furin cleavage, still encompassed the predicted BMP-1 cleavage sites. It was purified and tested as a substrate for BMP-1. In parallel, the release of the C-propeptide in the culture medium was inhibited by the addition of a specific furin inhibitor, allowing the re-examination of BMP-1 activity on the intact molecule. We showed that BMP-1 does cleave both substrates at one of the two predicted C-proteinase cleavage sites. Our results favor a role for PCP/BMP-1 in physiological C-terminal processing of procollagen V and imply a general mechanism for fibrillar collagen C-terminal processing.
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Affiliation(s)
- E Kessler
- Tel-Aviv University Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Sheba Medical Center, Tel-Hashomer 52621, Israel
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12
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Abstract
Bone morphogenetic proteins (BMPs) are bone-derived factors capable of inducing ectopic bone formation. Unlike other BMPs, BMP-1 is not like transforming growth factor-beta (TGF-beta), but it is the prototype of a family of putative proteases implicated in pattern formation during development in diverse organisms. Although some members of this group, such as Drosophila tolloid (TLD), are postulated to activate TGF-beta-like proteins, actual substrates are unknown. Procollagen C-proteinase (PCP) cleaves the COOH-propeptides of procollagens I, II, and III to yield the major fibrous components of vertebrate extracellular matrix. Here it is shown that BMP-1 and PCP are identical. This demonstration of enzymatic activity for a BMP-1/TLD-like protein links an enzyme involved in matrix deposition to genes involved in pattern formation.
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Affiliation(s)
- E Kessler
- Maurice and Gabriela Goldschleger Eye Research Institute, Tel Aviv University Sackler Faculty of Medicine, Sheba Medical Center, Tel Hashomer, Israel
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13
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Takahara K, Kessler E, Biniaminov L, Brusel M, Eddy RL, Jani-Sait S, Shows TB, Greenspan DS. Type I procollagen COOH-terminal proteinase enhancer protein: identification, primary structure, and chromosomal localization of the cognate human gene (PCOLCE). J Biol Chem 1994; 269:26280-5. [PMID: 7523404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Type I procollagen COOH-terminal proteinase (C-proteinase) enhancer, a glycoprotein that binds to the COOH-terminal propeptide of type I procollagen and enhances procollagen C-proteinase activity, was purified from mouse fibroblast culture media. Partial amino acid sequences obtained from proteolytic fragments were found to have identity with the deduced amino acid sequence of a cDNA clone of unknown function, previously isolated from a mouse astrocyte library. Sequences of mouse enhancer cDNA, obtained in the present study, predict a approximately 50-kDa, 468-amino acid protein that differs from the 43-kDa, 402-amino acid protein predicted by the previously reported astrocyte-derived clone. Human cDNAs encode an enhancer of 449 amino acids. Previous biochemical studies have found the mouse enhancer as a 55-kDa form, which is readily processed to 36- and 34-kDa forms, retaining full C-proteinase enhancing activity and the ability to bind the COOH-terminal propeptide. Data presented here show the 36-kDa form to correspond to the amino-terminal portion of the 55-kDa protein. This is the most conserved region between mouse and human enhancers, comprising two domains with homology to domains found in a number of proteases and proteins with developmental functions. Such domains are thought to mediate interactions between proteins. Mouse enhancer RNA is shown to be at highest levels in collagen-rich tissues, especially tendon. The human enhancer gene, PCOLCE, is localized to 7q21.3-->q22, the same chromosomal region containing the type I collagen alpha 2 chain gene, COL1A2.
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Affiliation(s)
- K Takahara
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison 53706
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14
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Takahara K, Kessler E, Biniaminov L, Brusel M, Eddy RL, Jani-Sait S, Shows TB, Greenspan DS. Type I procollagen COOH-terminal proteinase enhancer protein: identification, primary structure, and chromosomal localization of the cognate human gene (PCOLCE). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47191-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Prigojin H, Brusel M, Fuchs O, Shomrat R, Legum C, Nudel U, Yaffe D. Detection of Duchenne muscular dystrophy gene products in amniotic fluid and chorionic villus sampling cells. FEBS Lett 1993; 335:223-30. [PMID: 8253201 DOI: 10.1016/0014-5793(93)80734-c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have examined the expression of several Duchenne muscular dystrophy (DMD) gene products in amniotic fluid (AF) and chorionic villus sampling (CVS) cells. Variable amounts of dystrophin could be detected in most CVS and AF samples by immunoprecipitation followed by Western blot analysis. PCR analysis demonstrated the presence of the muscle type dystrophin mRNA in all AF cell cultures. The brain type dystrophin mRNA was also detected in some of these cultures. These DMD gene transcripts are of fetal origin and are produced by most or all clonable AF cells. The results may facilitate the development of a method for prenatal diagnosis of DMD, based on the expression of the gene in AF and CVS cells.
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Affiliation(s)
- H Prigojin
- Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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