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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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Ricobaraza A, Bunuales M, Gonzalez-Aparicio M, Fadila S, Rubinstein M, Vides-Urrestarazu I, Banderas J, Sola-Sevilla N, Sanchez-Carpintero R, Lanciego JL, Roda E, Honrubia A, Arnaiz P, Hernandez-Alcoceba R. Preferential expression of SCN1A in GABAergic neurons improves survival and epileptic phenotype in a mouse model of Dravet syndrome. J Mol Med (Berl) 2023; 101:1587-1601. [PMID: 37819378 PMCID: PMC10697872 DOI: 10.1007/s00109-023-02383-8] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The SCN1A gene encodes the alpha subunit of a voltage-gated sodium channel (Nav1.1), which is essential for the function of inhibitory neurons in the brain. Mutations in this gene cause severe encephalopathies such as Dravet syndrome (DS). Upregulation of SCN1A expression by different approaches has demonstrated promising therapeutic effects in preclinical models of DS. Limiting the effect to inhibitory neurons may contribute to the restoration of brain homeostasis, increasing the safety and efficacy of the treatment. In this work, we have evaluated different approaches to obtain preferential expression of the full SCN1A cDNA (6 Kb) in GABAergic neurons, using high-capacity adenoviral vectors (HC-AdV). In order to favour infection of these cells, we considered ErbB4 as a surface target. Incorporation of the EGF-like domain from neuregulin 1 alpha (NRG1α) in the fiber of adenovirus capsid allowed preferential infection in cells lines expressing ErbB4. However, it had no impact on the infectivity of the vector in primary cultures or in vivo. For transcriptional control of transgene expression, we developed a regulatory sequence (DP3V) based on the Distal-less homolog enhancer (Dlx), the vesicular GABA transporter (VGAT) promoter, and a portion of the SCN1A gene. The hybrid DP3V promoter allowed preferential expression of transgenes in GABAergic neurons both in vitro and in vivo. A new HC-AdV expressing SCN1A under the control of this promoter showed improved survival and amelioration of the epileptic phenotype in a DS mouse model. These results increase the repertoire of gene therapy vectors for the treatment of DS and indicate a new avenue for the refinement of gene supplementation in this disease. KEY MESSAGES: Adenoviral vectors can deliver the SCN1A cDNA and are amenable for targeting. An adenoviral vector displaying an ErbB4 ligand in the capsid does not target GABAergic neurons. A hybrid promoter allows preferential expression of transgenes in GABAergic neurons. Preferential expression of SCN1A in GABAergic cells is therapeutic in a Dravet syndrome model.
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Affiliation(s)
- Ana Ricobaraza
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Maria Bunuales
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Saja Fadila
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, 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
| | - Irene Vides-Urrestarazu
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Julliana Banderas
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Noemi Sola-Sevilla
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
| | - Jose Luis Lanciego
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CiberNed), Madrid, Spain
| | - Elvira Roda
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Adriana Honrubia
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Patricia Arnaiz
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain.
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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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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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Livraghi-Butrico A, Grubb B, Carpenter J, Danielsen S, Markovetz M, Chen G, Radicioni G, Saldana-Montavon A, Sun L, Gutay M, Vilar J, Ehre C, Thornton D, Cowley D, O'Neal W, Hill D, Button B, Kesimer M, Rubinstein M, Boucher R. 404 Why are mucins so gigantic, and is it rational to sever them to aid mucus clearance? J Cyst Fibros 2022. [DOI: 10.1016/s1569-1993(22)01094-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Karmon G, Sragovich S, Hacohen-Kleiman G, Ben-Horin-Hazak I, Kasparek P, Schuster B, Sedlacek R, Pasmanik-Chor M, Theotokis P, Touloumi O, Zoidou S, Huang L, Wu PY, Shi R, Kapitansky O, Lobyntseva A, Giladi E, Shapira G, Shomron N, Bereswill S, Heimesaat MM, Grigoriadis N, McKinney RA, Rubinstein M, Gozes I. Novel ADNP Syndrome Mice Reveal Dramatic Sex-Specific Peripheral Gene Expression With Brain Synaptic and Tau Pathologies. Biol Psychiatry 2022; 92:81-95. [PMID: 34865853 DOI: 10.1016/j.biopsych.2021.09.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/19/2021] [Accepted: 09/17/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND ADNP is essential for embryonic development. As such, de novo ADNP mutations lead to an intractable autism/intellectual disability syndrome requiring investigation. METHODS Mimicking humans, CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 editing produced mice carrying heterozygous Adnp p.Tyr718∗ (Tyr), a paralog of the most common ADNP syndrome mutation. Phenotypic rescue was validated by treatment with the microtubule/autophagy-protective ADNP fragment NAPVSIPQ (NAP). RESULTS RNA sequencing of spleens, representing a peripheral biomarker source, revealed Tyr-specific sex differences (e.g., cell cycle), accentuated in females (with significant effects on antigen processing and cellular senescence) and corrected by NAP. Differentially expressed, NAP-correctable transcripts, including the autophagy and microbiome resilience-linked FOXO3, were also deregulated in human patient-derived ADNP-mutated lymphoblastoid cells. There were also Tyr sex-specific microbiota signatures. Phenotypically, Tyr mice, similar to patients with ADNP syndrome, exhibited delayed development coupled with sex-dependent gait defects. Speech acquisition delays paralleled sex-specific mouse syntax abnormalities. Anatomically, dendritic spine densities/morphologies were decreased with NAP amelioration. These findings were replicated in the Adnp+/- mouse, including Foxo3 deregulation, required for dendritic spine formation. Grooming duration and nociception threshold (autistic traits) were significantly affected only in males. Early-onset tauopathy was accentuated in males (hippocampus and visual cortex), mimicking humans, and was paralleled by impaired visual evoked potentials and correction by acute NAP treatment. CONCLUSIONS Tyr mice model ADNP syndrome pathology. The newly discovered ADNP/NAP target FOXO3 controls the autophagy initiator LC3 (microtubule-associated protein 1 light chain 3), with known ADNP binding to LC3 augmented by NAP, protecting against tauopathy. NAP amelioration attests to specificity, with potential for drug development targeting accessible biomarkers.
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Affiliation(s)
- Gidon Karmon
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Shlomo Sragovich
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Gal Hacohen-Kleiman
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Inbar Ben-Horin-Hazak
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Petr Kasparek
- Department of Transgenic Models of Diseases and Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Björn Schuster
- Department of Transgenic Models of Diseases and Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Radislav Sedlacek
- Department of Transgenic Models of Diseases and Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Paschalis Theotokis
- Department of Neurology, Laboratory of Experimental Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Olga Touloumi
- Department of Neurology, Laboratory of Experimental Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Sofia Zoidou
- Department of Neurology, Laboratory of Experimental Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Linxuan Huang
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Pei You Wu
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Roy Shi
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Oxana Kapitansky
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Alexandra Lobyntseva
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Eliezer Giladi
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Guy Shapira
- Department of Cell and Developmental Biology and Edmond J. Safra Center for Bioinformatics, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noam Shomron
- Department of Cell and Developmental Biology and Edmond J. Safra Center for Bioinformatics, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Stefan Bereswill
- Gastrointestinal Microbiology Research Group, Institute for Microbiology, Infectious Diseases and Immunology, Charité-University Medicine Berlin, Berlin, Germany
| | - Markus M Heimesaat
- Gastrointestinal Microbiology Research Group, Institute for Microbiology, Infectious Diseases and Immunology, Charité-University Medicine Berlin, Berlin, Germany
| | - Nikolaos Grigoriadis
- Department of Neurology, Laboratory of Experimental Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - R Anne McKinney
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Moran Rubinstein
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel; Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Illana Gozes
- Elton Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience and Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel.
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8
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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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9
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Cappelle SI, Moreau M, Karmali R, Iconaru L, Baleanu F, Kinnard V, Paesmans M, Rozenberg S, Rubinstein M, Surquin M, Blard PH, Chapurlat R, Body JJ, Bergmann P. Discriminating value of HR-pQCT for fractures in women with similar FRAX scores: A substudy of the FRISBEE cohort. Bone 2021; 143:115613. [PMID: 32871273 DOI: 10.1016/j.bone.2020.115613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/29/2020] [Accepted: 08/21/2020] [Indexed: 11/30/2022]
Abstract
Areal bone mineral density (aBMD) has a low sensitivity to identify women at high fracture risk. The FRAX algorithm, by combining several clinical risk factors, might improve fracture prediction compared to aBMD alone. Several micro-architectural and biomechanical parameters which can be measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) are associated with fracture risk. HR-pQCT in combination or not with finite element analysis (FEA) may be used to improve bone strength prediction. Our aim was to assess whether HR-pQCT measurements (densities, cortical and trabecular microarchitecture, biomechanical proprieties assessed by FEA) had an added value in predicting fractures in a subgroup of women belonging to the Belgian FRISBEE cohort. One hundred nineteen women who sustained a fracture (aged 60 to 85 years) during the initial follow-up of our cohort had a radius and tibia examination by HR-pQCT and were compared with controls matched for their FRAX score at baseline. We found that low distal radius total (OR = 1.41 [1.07-1.86] per SD, p < 0.05) and trabecular densities (OR = 1.45 [1.10-1.90], p < 0.01), trabecular number (OR = 1.32 [1.01-1.72], p < 0.05), intra individual distribution of separation (OR = 0.73 [0.54-0.99], p < 0.05) as several FEA parameters were significantly associated with fractures. At the distal tibia, impaired cortical density (OR = 1.32 [1.03-1.70] per SD, p < 0.05) and thickness (OR = 1.29 [1.01-1.63], p < 0.05) and apparent modulus (OR = 1.30 [1.01-1.66], p < 0.05) were significantly correlated with fractures. A low ultra distal radial aBMD (UDR) measured at the time of HR-pQCT was significantly associated with fractures (OR = 1.67 [1.22-2.28], p < 0.01). Women from both groups were followed further after the realization of the HR-pQCT and 46 new fractures were registered. In this second part of the study, low UDR aBMD (OR = 1.66 [1.18-2.35], p < 0.01), total (OR = 1.48 [1.08-2.03], p < 0.05), cortical (OR = 1.40 [1.04-1.87], p < 0.05) and trabecular (OR = 1.37 [1.01-1.85], p < 0.05) densities or apparent modulus (OR = 1.49 [1.07-2.05], p < 0.05) at the radius were associated with a significant increase of fracture risk. At the tibia, only the cortical density was significantly associated with the fracture risk (OR = 1.34 [1.02-2.76], p < 0.05). These results confirm the interest of HR-pQCT measurements for the evaluation of fracture risk, also in women matched for their baseline FRAX score. They also highlight that UDR aBMD contains pertinent information.
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Affiliation(s)
- S I Cappelle
- Department of Geriatrics, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium.
| | - M Moreau
- Data Centre, Bordet Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - R Karmali
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - L Iconaru
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - F Baleanu
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - V Kinnard
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - M Paesmans
- Data Centre, Bordet Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - S Rozenberg
- Department of Obstetrics and gynaecology, Université Libre de Bruxelles (ULB) and Vrije Universiteit (VUB), Brussels, Belgium
| | - M Rubinstein
- Department of Nuclear Medicine, Ixelles Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - M Surquin
- Department of Geriatrics, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - P-H Blard
- CNRS, Université de Lorraine, CRPG, F-54000 Nancy, France
| | - R Chapurlat
- INSERM Research Unit 1033-Lyos, Hôpital E. Herriot, Lyon, France
| | - J J Body
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - P Bergmann
- Department of Nuclear Medicine, CHU-Brugmann, Université Libre de Bruxelles (ULB), Brussels, Belgium
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Rabinski T, Sagiv ST, Hausman-Kedem M, Fattal-Valevski A, Rubinstein M, Avraham KB, Vatine GD. Reprogramming of two induced pluripotent stem cell lines from a heterozygous GRIN2D developmental and epileptic encephalopathy (DEE) patient (BGUi011-A) and from a healthy family relative (BGUi012-A). Stem Cell Res 2021; 51:102178. [PMID: 33482465 DOI: 10.1016/j.scr.2021.102178] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 10/22/2022] Open
Abstract
The GLUN2D subunit of the N-methylD-aspartate receptor (NMDAR) is encoded by the GRIN2D gene. Mutations in GRIN2D have been associated with neurodevelopmental and epileptic encephalopathies. Access to patient samples harboring mutations in GRIN2D can contribute to understanding the role of NMDAR in neuronal development and function. We report the generation of induced pluripotent stem cell (iPSC) lines from a GRIN2D-developmental and epileptic encephalopathy (DEE) patient, carrying a de novo c.1999G>A heterozygous pathogenic variant, and his healthy parent. Generated lines highly expressed pluripotency markers, spontaneously differentiated into the three germ layers, retained the deficiency-causing mutation, and displayed normal karyotypes.
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Affiliation(s)
- Tatiana Rabinski
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Sivan T Sagiv
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Moran Hausman-Kedem
- Pediatric Neurology Institute, Dana-Dewk Children's Hospital, Tel-Aviv Sourasky Medical Center, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Aviva Fattal-Valevski
- Pediatric Neurology Institute, Dana-Dewk Children's Hospital, Tel-Aviv Sourasky Medical Center, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Moran Rubinstein
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; Goldschleger Eye Research Institute, Tel Aviv University, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Gad D Vatine
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
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11
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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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12
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Curci L, Brukman NG, Weigel Muñoz M, Rojo D, Carvajal G, Sulzyk V, Gonzalez SN, Rubinstein M, Da Ros VG, Cuasnicú PS. Functional redundancy and compensation: Deletion of multiple murine Crisp genes reveals their essential role for male fertility. FASEB J 2020; 34:15718-15733. [PMID: 33037689 DOI: 10.1096/fj.202001406r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 06/03/2020] [Revised: 07/16/2020] [Accepted: 07/27/2020] [Indexed: 12/18/2022]
Abstract
Mammalian Cysteine-RIch Secretory Protein (CRISP) family includes four members present in sperm and reported to regulate Ca2+ channels and fertilization. Based on our previous observations using single knockouts models and suggesting the existence of functional compensation among CRISP proteins, we investigated their relevance for male fertility by generating multiple Crisp gene mutants by CRISPR/Cas9 technology. Whereas targeting of Crisp1 and Crisp3 yielded subfertile males with early embryo developmental defects, the same deletion in zygotes from fertile Crisp2-/- .Crisp4-/- mice led to the generation of both triple and quadruple knockout mice exhibiting a complete or severe disruption of male fertility due to a combination of sperm transport, fertilization, and embryo developmental defects linked to intracellular Ca2+ dysregulation. These observations reveal that CRISP proteins are essential for male fertility and organize in functional modules that contribute distinctly to fertility success, bringing insights into the mechanisms underlying functional redundancy/compensation in protein families and emphasizing the importance of generating multiple and not just single knockout which might be masking the true functional relevance of family genes.
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Affiliation(s)
- L Curci
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - N G Brukman
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - M Weigel Muñoz
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - D Rojo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - G Carvajal
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - V Sulzyk
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - S N Gonzalez
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - M Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - V G Da Ros
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - P S Cuasnicú
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
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Fadila S, Quinn S, Turchetti Maia A, Yakubovich D, Ovadia M, Anderson KL, Giladi M, Rubinstein M. Convulsive seizures and some behavioral comorbidities are uncoupled in the
Scn1a
A1783V
Dravet syndrome mouse model. Epilepsia 2020; 61:2289-2300. [DOI: 10.1111/epi.16662] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 02/03/2023]
Affiliation(s)
- Saja Fadila
- 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
| | - 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
| | - Ana Turchetti Maia
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Daniel Yakubovich
- Department of Physiology and Pharmacology Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Schneider Children's Medical Center of Israel Petah Tikvah 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
| | - Karen L. Anderson
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Moshe Giladi
- Department of Physiology and Pharmacology 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
- 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
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14
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Nadar-Ponniah PT, Taiber S, Caspi M, Koffler-Brill T, Dror AA, Siman-Tov R, Rubinstein M, Padmanabhan K, Luxenburg C, Lang RA, Avraham KB, Rosin-Arbesfeld R. Striatin Is Required for Hearing and Affects Inner Hair Cells and Ribbon Synapses. Front Cell Dev Biol 2020; 8:615. [PMID: 32766247 PMCID: PMC7381154 DOI: 10.3389/fcell.2020.00615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/22/2020] [Indexed: 12/22/2022] Open
Abstract
Striatin, a subunit of the serine/threonine phosphatase PP2A, is a core member of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complexes. The protein is expressed in the cell junctions between epithelial cells, which play a role in maintaining cell-cell adhesion. Since the cell junctions are crucial for the function of the mammalian inner ear, we examined the localization and function of striatin in the mouse cochlea. Our results show that in neonatal mice, striatin is specifically expressed in the cell-cell junctions of the inner hair cells, the receptor cells in the mammalian cochlea. Auditory brainstem response measurements of striatin-deficient mice indicated a progressive, high-frequency hearing loss, suggesting that striatin is essential for normal hearing. Moreover, scanning electron micrographs of the organ of Corti revealed a moderate degeneration of the outer hair cells in the middle and basal regions, concordant with the high-frequency hearing loss. Additionally, striatin-deficient mice show aberrant ribbon synapse maturation. Loss of the outer hair cells, combined with the aberrant ribbon synapse distribution, may lead to the observed auditory impairment. Together, these results suggest a novel function for striatin in the mammalian auditory system.
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Affiliation(s)
- Prathamesh T. Nadar-Ponniah
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Amiel A. Dror
- Department of Otolaryngology, Head and Neck Surgery, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ronen Siman-Tov
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Krishnanand Padmanabhan
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Luxenburg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Richard A. Lang
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Karen B. Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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15
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Iconaru L, Smeys C, Baleanu F, Kinnard V, Moreau M, Cappelle S, Surquin M, Rubinstein M, Rozenberg S, Paesmans M, Karmali R, Bergmann P, Body JJ. Osteoporosis treatment gap in a prospective cohort of volunteer women. Osteoporos Int 2020; 31:1377-1382. [PMID: 32128600 DOI: 10.1007/s00198-020-05339-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/06/2020] [Indexed: 12/11/2022]
Abstract
UNLABELLED Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture. The high treatment gap in our cohort consisted of unselected volunteer patients highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment. INTRODUCTION Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture, with a treatment gap around 80%. This can have dramatic consequences for patients and the healthcare systems. METHODS In this study based on longitudinal data from the FRISBEE (Fracture RIsk Brussels Epidemiological Enquiry) cohort of 3560 volunteer women aged 60 to 85 years, we evaluated the 1-year treatment gap after a first major incident fragility fracture. RESULTS There were 386 first validated fragility fractures, 285 major osteoporotic fractures (MOF) and 101 "other major" fractures. The rate of untreated patients was 85.0% (82.8% for MOF versus 91.0 % for "other major" fracture sites) (p = 0.04), with a lower rate for spine (70.5%) and hip (72.5%) versus shoulder (91.6%) and wrist (94.1%) (p < 0.0001). More specifically, the treatment gap for patients with osteoporosis, defined by a T-score < - 2.5 SD was 74.6% versus 76.5% for patients with osteoporosis defined by the presence of hip, shoulder, or spine fractures, independently of DXA results. When considering age groups, the rate of untreated women was 87.9% for women 60-70 years old, 88.2% between 70 and 80 years and 77.8% above 80 years (p = 0.03), with a greater difference between women who were younger or older than 80 years at inclusion: 88.1% versus 77.8% (p = 0.009). A diagnosis of osteoporosis (p = 0.01) and age (p = 0.03) were the only clinical risk factors (CRFs) significantly associated with treatment initiation. CONCLUSIONS This study highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.
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Affiliation(s)
- L Iconaru
- Department of Endocrinology, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium.
| | - C Smeys
- Department of Geriatrics, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - F Baleanu
- Department of Endocrinology, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - V Kinnard
- Department of Internal Medicine, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - M Moreau
- Data Centre, Inst. J. Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - S Cappelle
- Department of Geriatrics, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - M Surquin
- Department of Geriatrics, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - M Rubinstein
- Department of Nuclear Medicine, Ixelles Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - S Rozenberg
- Department of Gynecology, CHU St Pierre, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - M Paesmans
- Data Centre, Inst. J. Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - R Karmali
- Department of Endocrinology, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - P Bergmann
- Department of Nuclear Medicine, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
| | - J J Body
- Department of Endocrinology, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium
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Wrangle J, Velcheti V, Patel M, Sweiderska-syn M, Macpherson L, Coggins C, Kreig C, Redmond W, Rock A, Lee J, Rubinstein M. A37 N-803 Plus Nivolumab for Advanced or Metastatic Non-Small Cell Lung Cancer: Update on Phase II Experience of Combination PD1 Blockade with an IL-15 Superagonist. J Thorac Oncol 2020. [DOI: 10.1016/j.jtho.2019.12.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Tunnage I, Stasenko M, Ashley C, Rubinstein M, Latham A, Mueller J, Leitao M, Friedman C, Makker V, Soslow R, Weigelt B, DeLair D, Hyman D, Aghajanian C, Abu-Rustum N, Cadoo K. Clinical outcomes of patients with pole mutated endometrioid endometrial cancer. Gynecol Oncol 2019. [DOI: 10.1016/j.ygyno.2019.03.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Huang Q, Ahn J, Parisi D, Chang T, Hassager O, Panyukov S, Rubinstein M, Vlassopoulos D. Unexpected Stretching of Entangled Ring Macromolecules. Phys Rev Lett 2019; 122:208001. [PMID: 31172770 PMCID: PMC6778440 DOI: 10.1103/physrevlett.122.208001] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Indexed: 05/11/2023]
Abstract
In the melt state at equilibrium, entangled nonconcatenated ring macromolecules adapt more compact conformations compared to their linear analogs and do not form an entanglement network. We show here that, when subjected to uniaxial stretching, they exhibit a unique response, which sets them apart from any other polymer. Remarkably, whereas both linear and ring polymers strain-harden, the viscosity of the rings increases dramatically (the melt thickens) at very low stretch rates due to the unraveling of their conformations along the stretching direction. At high rates, stretching leads to viscosity thinning similar to that of entangled linear polymers, albeit with subtle differences.
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Affiliation(s)
- Q Huang
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - J Ahn
- Division of Advanced Materials Science and Department of Chemistry, Pohang University of Science and Technology, Pohang 790784, Korea
| | - D Parisi
- Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas (FORTH), Heraklion, Crete 70013, Greece
- Department of Materials Science and Technology, University of Crete, Heraklion, Crete 71003, Greece
| | - T Chang
- Division of Advanced Materials Science and Department of Chemistry, Pohang University of Science and Technology, Pohang 790784, Korea
| | - O Hassager
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - S Panyukov
- P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 117924, Russia
| | - M Rubinstein
- Departments of Mechanical Engineering and Materials Science, Biomedical Engineering, Chemistry, and Physics, Duke University, Durham, North Carolina 27708, USA
| | - D Vlassopoulos
- Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas (FORTH), Heraklion, Crete 70013, Greece
- Department of Materials Science and Technology, University of Crete, Heraklion, Crete 71003, Greece
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Styr B, Gonen N, Zarhin D, Ruggiero A, Atsmon R, Gazit N, Braun G, Frere S, Vertkin I, Shapira I, Harel M, Heim LR, Katsenelson M, Rechnitz O, Fadila S, Derdikman D, Rubinstein M, Geiger T, Ruppin E, Slutsky I. Mitochondrial Regulation of the Hippocampal Firing Rate Set Point and Seizure Susceptibility. Neuron 2019; 102:1009-1024.e8. [PMID: 31047779 PMCID: PMC6559804 DOI: 10.1016/j.neuron.2019.03.045] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/07/2019] [Accepted: 03/28/2019] [Indexed: 01/08/2023]
Abstract
Maintaining average activity within a set-point range constitutes a fundamental property of central neural circuits. However, whether and how activity set points are regulated remains unknown. Integrating genome-scale metabolic modeling and experimental study of neuronal homeostasis, we identified mitochondrial dihydroorotate dehydrogenase (DHODH) as a regulator of activity set points in hippocampal networks. The DHODH inhibitor teriflunomide stably suppressed mean firing rates via synaptic and intrinsic excitability mechanisms by modulating mitochondrial Ca2+ buffering and spare respiratory capacity. Bi-directional activity perturbations under DHODH blockade triggered firing rate compensation, while stabilizing firing to the lower level, indicating a change in the firing rate set point. In vivo, teriflunomide decreased CA3-CA1 synaptic transmission and CA1 mean firing rate and attenuated susceptibility to seizures, even in the intractable Dravet syndrome epilepsy model. Our results uncover mitochondria as a key regulator of activity set points, demonstrate the differential regulation of set points and compensatory mechanisms, and propose a new strategy to treat epilepsy.
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Affiliation(s)
- Boaz Styr
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Nir Gonen
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Daniel Zarhin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Antonella Ruggiero
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Refaela Atsmon
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Neta Gazit
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Gabriella Braun
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Samuel Frere
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Irena Vertkin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ilana Shapira
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Michal Harel
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Leore R Heim
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Maxim Katsenelson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ohad Rechnitz
- Department of Neuroscience, Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, 31096 Haifa, Israel
| | - Saja Fadila
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; The Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Dori Derdikman
- Department of Neuroscience, Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, 31096 Haifa, Israel
| | - Moran Rubinstein
- Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel; Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; The Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Tamar Geiger
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Eytan Ruppin
- Cancer Data Science Lab (CDSL), National Cancer Institute, NIH, Bethesda, MD, USA
| | - Inna Slutsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel.
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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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21
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Rubinstein M, Patowary A, Stanaway IB, McCord E, Nesbitt RR, Archer M, Scheuer T, Nickerson D, Raskind WH, Wijsman EM, Bernier R, Catterall WA, Brkanac Z. Association of rare missense variants in the second intracellular loop of Na V1.7 sodium channels with familial autism. Mol Psychiatry 2018; 23:231-239. [PMID: 27956748 PMCID: PMC5468514 DOI: 10.1038/mp.2016.222] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 10/07/2016] [Accepted: 10/17/2016] [Indexed: 01/21/2023]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder often accompanied by intellectual disability, language impairment and medical co-morbidities. The heritability of autism is high and multiple genes have been implicated as causal. However, most of these genes have been identified in de novo cases. To further the understanding of familial autism, we performed whole-exome sequencing on five families in which second- and third-degree relatives were affected. By focusing on novel and protein-altering variants, we identified a small set of candidate genes. Among these, a novel private missense C1143F variant in the second intracellular loop of the voltage-gated sodium channel NaV1.7, encoded by the SCN9A gene, was identified in one family. Through electrophysiological analysis, we show that NaV1.7C1143F exhibits partial loss-of-function effects, resulting in slower recovery from inactivation and decreased excitability in cultured cortical neurons. Furthermore, for the same intracellular loop of NaV1.7, we found an excess of rare variants in a case-control variant-burden study. Functional analysis of one of these variants, M932L/V991L, also demonstrated reduced firing in cortical neurons. However, although this variant is rare in Caucasians, it is frequent in Latino population, suggesting that genetic background can alter its effects on phenotype. Although the involvement of the SCN1A and SCN2A genes encoding NaV1.1 and NaV1.2 channels in de novo ASD has previously been demonstrated, our study indicates the involvement of inherited SCN9A variants and partial loss-of-function of NaV1.7 channels in the etiology of rare familial ASD.
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Affiliation(s)
- M Rubinstein
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - A Patowary
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - I B Stanaway
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - E McCord
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - R R Nesbitt
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - M Archer
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - T Scheuer
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - D Nickerson
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - W H Raskind
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA,Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA
| | - E M Wijsman
- Department of Genome Sciences, University of Washington, Seattle, WA, USA,Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA,Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - R Bernier
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - W A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA, USA,Department of Pharmacology, University of Washington, Seattle, WA 98195, USA E-mail:
| | - Z Brkanac
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA,Department of Psychiatry and Behavioral Science, University of Washington, 1959N.E. Pacific Street, Room BB1526, Seattle, WA 98195-6560, USA. E-mail:
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22
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Cappelle S, Ramon I, Dekelver C, Rozenberg S, Baleanu F, Karmali R, Rubinstein M, Tondeur M, Moreau M, Paesmans M, Bergmann P, Body JJ. Distribution of clinical risk factors for fracture in a Brussels cohort of postmenopausal women: The FRISBEE study and comparison with other major cohort studies. Maturitas 2017; 106:1-7. [DOI: 10.1016/j.maturitas.2017.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 08/08/2017] [Accepted: 08/11/2017] [Indexed: 11/15/2022]
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Dascal N, Rubinstein M. Lithium reduces the span of G protein-activated K + (GIRK) channel inhibition in hippocampal neurons. Bipolar Disord 2017; 19:568-574. [PMID: 28895268 DOI: 10.1111/bdi.12536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/20/2017] [Indexed: 01/01/2023]
Abstract
OBJECTIVES Lithium (Li+ ) is one of the most widely used treatments for bipolar disorder (BD). However, the molecular and neuronal basis of BD, as well as the mechanisms of Li+ actions are poorly understood. Cellular and biochemical studies identified G proteins as being among the cellular targets for Li+ action, while genetic studies indicated an association with the KCNJ3 gene, which encodes the G protein-activated inwardly rectifying K+ (GIRK) channels. GIRK channels regulate neuronal excitability by mediating the inhibitory effects of multiple neurotransmitters and contribute to the resting potassium conductance. Here, we explored the effects of therapeutic dose of Li+ on neuronal excitability and the role of GIRK channels in Li+ actions. METHODS Effects of Li+ on excitability were studied in hippocampal brain slices using whole-cell electrophysiological recordings. RESULTS A therapeutic dose of Li+ (1 mM) dually regulated the function of GIRK channels in hippocampal slices. Li+ hyperpolarized the resting membrane potential of hippocampal CA1 pyramidal neurons and prolonged the latency to reach the action potential threshold and peak. These effects were abolished in the presence of tertiapin, a specific GIRK channel blocker, and at doses above the therapeutic window (2 mM). In contrast, Li+ reduced GIRK channel opening induced by GABAB receptor (GABAB R) activation, causing reduced hyperpolarization of the membrane potential, attenuated reduction of input resistance, and a smaller decrease of neuronal firing. CONCLUSIONS A therapeutic dose of Li+ reduces the span of GIRK channel-mediated inhibition due to enhancement of basal GIRK currents and inhibition of GABAB R evoked responses, providing an important link between Li+ action, neuronal excitability, and cellular and genetic targets of BD.
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Affiliation(s)
- Nathan Dascal
- The Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,The Goldschleger Eye Research Institute, Sheba Medical Center, Tel Hashomer, Israel.,The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Rubinstein M, Hirway P, Zonfrillo M. 281 Incidence and Predictors of Elbow Injury in Children With Distal Forearm Fractures. Ann Emerg Med 2017. [DOI: 10.1016/j.annemergmed.2017.07.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Bello EP, Casas-Cordero R, Galiñanes GL, Casey E, Belluscio MA, Rodríguez V, Noaín D, Murer MG, Rubinstein M. Inducible ablation of dopamine D2 receptors in adult mice impairs locomotion, motor skill learning and leads to severe parkinsonism. Mol Psychiatry 2017; 22:595-604. [PMID: 27431292 DOI: 10.1038/mp.2016.105] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 04/20/2016] [Accepted: 05/06/2016] [Indexed: 11/09/2022]
Abstract
Motor execution and planning are tightly regulated by dopamine D1 and D2 receptors present in basal ganglia circuits. Although stimulation of D1 receptors is known to enhance motor function, the global effect of D2 receptor (D2R) stimulation or blockade remains highly controversial, with studies showing increasing, decreasing or no changes in motor activity. Moreover, pharmacological and genetic attempts to block or eliminate D2R have led to controversial results that questioned the importance of D2R in motor function. In this study, we generated an inducible Drd2 null-allele mouse strain that circumvented developmental compensations found in constitutive Drd2-/- mice and allowed us to directly evaluate the participation of D2R in spontaneous locomotor activity and motor learning. We have found that loss of D2R during adulthood causes severe motor impairments, including hypolocomotion, deficits in motor coordination, impaired learning of new motor routines and spontaneous catatonia. Moreover, severe motor impairment, resting tremor and abnormal gait and posture, phenotypes reminiscent of Parkinson's disease, were evident when the mutation was induced in aged mice. Altogether, the conditional Drd2 knockout model studied here revealed the overall fundamental contribution of D2R in motor functions and explains some of the side effects elicited by D2R blockers when used in neurological and psychiatric conditions, including schizophrenia, bipolar disorder, Tourette's syndrome, dementia, alcohol-induced delusions and obsessive-compulsive disorder.
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Affiliation(s)
- E P Bello
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - R Casas-Cordero
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - G L Galiñanes
- Instituto de Fisiología y Biofísica Bernardo Houssay, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - E Casey
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M A Belluscio
- Instituto de Fisiología y Biofísica Bernardo Houssay, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - V Rodríguez
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - D Noaín
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M G Murer
- Instituto de Fisiología y Biofísica Bernardo Houssay, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
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Zhou Y, Rubinstein M, Low MJ, Kreek MJ. Hypothalamic-specific proopiomelanocortin deficiency reduces alcohol drinking in male and female mice. Genes Brain Behav 2017; 16:449-461. [PMID: 27870313 DOI: 10.1111/gbb.12362] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 11/07/2016] [Accepted: 11/16/2016] [Indexed: 01/21/2023]
Abstract
Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE-/-), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE-/- mice of both sexes had less intake and less preference. Although nPE-/- showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE-/- showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE-/- of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE-/- did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol 'binge' drinking, escalation and 'relapse', probably via hypothalamic-mediated mechanisms, with sex differences.
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Affiliation(s)
- Y Zhou
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| | - M Rubinstein
- INGEBI/CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - M J Low
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - M J Kreek
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
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Kopecka J, Panda E, Salaroglio I, Buondonno I, Barak S, Rubinstein M, Riganti C. C/EBP-β-LIP turnover decides cancer chemotherapy outcome. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)32802-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Yakubovich D, Berlin S, Kahanovitch U, Rubinstein M, Farhy-Tselnicker I, Styr B, Keren-Raifman T, Dessauer CW, Dascal N. A Quantitative Model of the GIRK1/2 Channel Reveals That Its Basal and Evoked Activities Are Controlled by Unequal Stoichiometry of Gα and Gβγ. PLoS Comput Biol 2015; 11:e1004598. [PMID: 26544551 PMCID: PMC4636287 DOI: 10.1371/journal.pcbi.1004598] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [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: 05/27/2015] [Accepted: 10/13/2015] [Indexed: 12/02/2022] Open
Abstract
G protein-gated K+ channels (GIRK; Kir3), activated by Gβγ subunits derived from Gi/o proteins, regulate heartbeat and neuronal excitability and plasticity. Both neurotransmitter-evoked (Ievoked) and neurotransmitter-independent basal (Ibasal) GIRK activities are physiologically important, but mechanisms of Ibasal and its relation to Ievoked are unclear. We have previously shown for heterologously expressed neuronal GIRK1/2, and now show for native GIRK in hippocampal neurons, that Ibasal and Ievoked are interrelated: the extent of activation by neurotransmitter (activation index, Ra) is inversely related to Ibasal. To unveil the underlying mechanisms, we have developed a quantitative model of GIRK1/2 function. We characterized single-channel and macroscopic GIRK1/2 currents, and surface densities of GIRK1/2 and Gβγ expressed in Xenopus oocytes. Based on experimental results, we constructed a mathematical model of GIRK1/2 activity under steady-state conditions before and after activation by neurotransmitter. Our model accurately recapitulates Ibasal and Ievoked in Xenopus oocytes, HEK293 cells and hippocampal neurons; correctly predicts the dose-dependent activation of GIRK1/2 by coexpressed Gβγ and fully accounts for the inverse Ibasal-Ra correlation. Modeling indicates that, under all conditions and at different channel expression levels, between 3 and 4 Gβγ dimers are available for each GIRK1/2 channel. In contrast, available Gαi/o decreases from ~2 to less than one Gα per channel as GIRK1/2's density increases. The persistent Gβγ/channel (but not Gα/channel) ratio support a strong association of GIRK1/2 with Gβγ, consistent with recruitment to the cell surface of Gβγ, but not Gα, by GIRK1/2. Our analysis suggests a maximal stoichiometry of 4 Gβγ but only 2 Gαi/o per one GIRK1/2 channel. The unique, unequal association of GIRK1/2 with G protein subunits, and the cooperative nature of GIRK gating by Gβγ, underlie the complex pattern of basal and agonist-evoked activities and allow GIRK1/2 to act as a sensitive bidirectional detector of both Gβγ and Gα. Many neurotransmitters and hormones inhibit the electric activity of excitable cells (such as cardiac cells and neurons) by activating a K+ channel, GIRK (G protein-gated Inwardly Rectifying K+ channel). GIRK channels also possess constitutive “basal” activity which contributes to regulation of neuronal and cardiac excitability and certain disorders, but the mechanism of this activity and its interrelation with the neurotransmitter-evoked activity are poorly understood. In this work we show that key features of basal and neurotransmitter-evoked activities are similar in cultured hippocampal neurons and in two model systems (mammalian HEK293 cells and Xenopus oocytes). Using experimental data of the neuronal GIRK1/2 channel function upon changes in GIRK and G protein concentrations, we constructed a mathematical model that quantitatively accounts for basal and evoked activity, and for the inverse correlation between the two. Our analysis suggests a novel and unexpected mechanism of interaction of GIRK1/2 with the G protein subunits, where the tetrameric GIRK channel can assemble with 4 molecules of the Gβγ subunits but only 2 molecules of Gα. GIRK is a prototypical effector of Gβγ, and the unequal stoichiometry of interaction with G protein subunits may have general implications for G protein signaling.
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Affiliation(s)
- Daniel Yakubovich
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Shai Berlin
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Uri Kahanovitch
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Isabella Farhy-Tselnicker
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Boaz Styr
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tal Keren-Raifman
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Carmen W. Dessauer
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas, United States of America
| | - Nathan Dascal
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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Rubinstein M, Han S, Tai C, Westenbroek RE, Hunker A, Scheuer T, Catterall WA. Dissecting the phenotypes of Dravet syndrome by gene deletion. Brain 2015; 138:2219-33. [PMID: 26017580 DOI: 10.1093/brain/awv142] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [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: 11/04/2014] [Accepted: 04/04/2015] [Indexed: 11/14/2022] Open
Abstract
Neurological and psychiatric syndromes often have multiple disease traits, yet it is unknown how such multi-faceted deficits arise from single mutations. Haploinsufficiency of the voltage-gated sodium channel Nav1.1 causes Dravet syndrome, an intractable childhood-onset epilepsy with hyperactivity, cognitive deficit, autistic-like behaviours, and premature death. Deletion of Nav1.1 channels selectively impairs excitability of GABAergic interneurons. We studied mice having selective deletion of Nav1.1 in parvalbumin- or somatostatin-expressing interneurons. In brain slices, these deletions cause increased threshold for action potential generation, impaired action potential firing in trains, and reduced amplification of postsynaptic potentials in those interneurons. Selective deletion of Nav1.1 in parvalbumin- or somatostatin-expressing interneurons increases susceptibility to thermally-induced seizures, which are strikingly prolonged when Nav1.1 is deleted in both interneuron types. Mice with global haploinsufficiency of Nav1.1 display autistic-like behaviours, hyperactivity and cognitive impairment. Haploinsufficiency of Nav1.1 in parvalbumin-expressing interneurons causes autistic-like behaviours, but not hyperactivity, whereas haploinsufficiency in somatostatin-expressing interneurons causes hyperactivity without autistic-like behaviours. Heterozygous deletion in both interneuron types is required to impair long-term spatial memory in context-dependent fear conditioning, without affecting short-term spatial learning or memory. Thus, the multi-faceted phenotypes of Dravet syndrome can be genetically dissected, revealing synergy in causing epilepsy, premature death and deficits in long-term spatial memory, but interneuron-specific effects on hyperactivity and autistic-like behaviours. These results show that multiple disease traits can arise from similar functional deficits in specific interneuron types.
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Affiliation(s)
- Moran Rubinstein
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - Sung Han
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - Chao Tai
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - Ruth E Westenbroek
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - Avery Hunker
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - Todd Scheuer
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280
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Kahanovitch U, Tsemakhovich V, Berlin S, Rubinstein M, Styr B, Castel R, Peleg S, Tabak G, Dessauer CW, Ivanina T, Dascal N. Recruitment of Gβγ controls the basal activity of G-protein coupled inwardly rectifying potassium (GIRK) channels: crucial role of distal C terminus of GIRK1. J Physiol 2014; 592:5373-90. [PMID: 25384780 DOI: 10.1113/jphysiol.2014.283218] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The G-protein coupled inwardly rectifying potassium (GIRK, or Kir3) channels are important mediators of inhibitory neurotransmission via activation of G-protein coupled receptors (GPCRs). GIRK channels are tetramers comprising combinations of subunits (GIRK1-4), activated by direct binding of the Gβγ subunit of Gi/o proteins. Heterologously expressed GIRK1/2 exhibit high, Gβγ-dependent basal currents (Ibasal) and a modest activation by GPCR or coexpressed Gβγ. Inversely, the GIRK2 homotetramers exhibit low Ibasal and strong activation by Gβγ. The high Ibasal of GIRK1 seems to be associated with its unique distal C terminus (G1-dCT), which is not present in the other subunits. We investigated the role of G1-dCT using electrophysiological and fluorescence assays in Xenopus laevis oocytes and protein interaction assays. We show that expression of GIRK1/2 increases the plasma membrane level of coexpressed Gβγ (a phenomenon we term 'Gβγ recruitment') but not of coexpressed Gαi3. All GIRK1-containing channels, but not GIRK2 homomers, recruited Gβγ to the plasma membrane. In biochemical assays, truncation of G1-dCT reduces the binding between the cytosolic parts of GIRK1 and Gβγ, but not Gαi3. Nevertheless, the truncation of G1-dCT does not impair activation by Gβγ. In fluorescently labelled homotetrameric GIRK1 channels and in the heterotetrameric GIRK1/2 channel, the truncation of G1-dCT abolishes Gβγ recruitment and decreases Ibasal. Thus, we conclude that G1-dCT carries an essential role in Gβγ recruitment by GIRK1 and, consequently, in determining its high basal activity. Our results indicate that G1-dCT is a crucial part of a Gβγ anchoring site of GIRK1-containing channels, spatially and functionally distinct from the site of channel activation by Gβγ.
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Affiliation(s)
- Uri Kahanovitch
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vladimir Tsemakhovich
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shai Berlin
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Moran Rubinstein
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Boaz Styr
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ruth Castel
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Sagit Peleg
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Galit Tabak
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, 77030, USA
| | - Tatiana Ivanina
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nathan Dascal
- Department of Physiology and Pharmacology and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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Rubinstein M, Westenbroek RE, Yu FH, Jones CJ, Scheuer T, Catterall WA. Genetic background modulates impaired excitability of inhibitory neurons in a mouse model of Dravet syndrome. Neurobiol Dis 2014; 73:106-17. [PMID: 25281316 DOI: 10.1016/j.nbd.2014.09.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [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: 07/01/2014] [Revised: 09/04/2014] [Accepted: 09/24/2014] [Indexed: 01/23/2023] Open
Abstract
Dominant loss-of-function mutations in voltage-gated sodium channel NaV1.1 cause Dravet Syndrome, an intractable childhood-onset epilepsy. NaV1.1(+/-) Dravet Syndrome mice in C57BL/6 genetic background exhibit severe seizures, cognitive and social impairments, and premature death. Here we show that Dravet Syndrome mice in pure 129/SvJ genetic background have many fewer seizures and much less premature death than in pure C57BL/6 background. These mice also have a higher threshold for thermally induced seizures, fewer myoclonic seizures, and no cognitive impairment, similar to patients with Genetic Epilepsy with Febrile Seizures Plus. Consistent with this mild phenotype, mutation of NaV1.1 channels has much less physiological effect on neuronal excitability in 129/SvJ mice. In hippocampal slices, the excitability of CA1 Stratum Oriens interneurons is selectively impaired, while the excitability of CA1 pyramidal cells is unaffected. NaV1.1 haploinsufficiency results in increased rheobase and threshold for action potential firing and impaired ability to sustain high-frequency firing. Moreover, deletion of NaV1.1 markedly reduces the amplification and integration of synaptic events, further contributing to reduced excitability of interneurons. Excitability is less impaired in inhibitory neurons of Dravet Syndrome mice in 129/SvJ genetic background. Because specific deletion of NaV1.1 in forebrain GABAergic interneuons is sufficient to cause the symptoms of Dravet Syndrome in mice, our results support the conclusion that the milder phenotype in 129/SvJ mice is caused by lesser impairment of sodium channel function and electrical excitability in their forebrain interneurons. This mild impairment of excitability of interneurons leads to a milder disease phenotype in 129/SvJ mice, similar to Genetic Epilepsy with Febrile Seizures Plus in humans.
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Affiliation(s)
- Moran Rubinstein
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Ruth E Westenbroek
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Frank H Yu
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Christina J Jones
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Todd Scheuer
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA.
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Baek JH, Rubinstein M, Scheuer T, Trimmer JS. Reciprocal changes in phosphorylation and methylation of mammalian brain sodium channels in response to seizures. J Biol Chem 2014; 289:15363-73. [PMID: 24737319 DOI: 10.1074/jbc.m114.562785] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [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: 12/19/2022] Open
Abstract
Voltage-gated sodium (Nav) channels initiate action potentials in brain neurons and are primary therapeutic targets for anti-epileptic drugs controlling neuronal hyperexcitability in epilepsy. The molecular mechanisms underlying abnormal Nav channel expression, localization, and function during development of epilepsy are poorly understood but can potentially result from altered posttranslational modifications (PTMs). For example, phosphorylation regulates Nav channel gating, and has been proposed to contribute to acquired insensitivity to anti-epileptic drugs exhibited by Nav channels in epileptic neurons. However, whether changes in specific brain Nav channel PTMs occur acutely in response to seizures has not been established. Here, we show changes in PTMs of the major brain Nav channel, Nav1.2, after acute kainate-induced seizures. Mass spectrometry-based proteomic analyses of Nav1.2 purified from the brains of control and seizure animals revealed a significant down-regulation of phosphorylation at nine sites, primarily located in the interdomain I-II linker, the region of Nav1.2 crucial for phosphorylation-dependent regulation of activity. Interestingly, Nav1.2 in the seizure samples contained methylated arginine (MeArg) at three sites. These MeArgs were adjacent to down-regulated sites of phosphorylation, and Nav1.2 methylation increased after seizure. Phosphorylation and MeArg were not found together on the same tryptic peptide, suggesting reciprocal regulation of these two PTMs. Coexpression of Nav1.2 with the primary brain arginine methyltransferase PRMT8 led to a surprising 3-fold increase in Nav1.2 current. Reciprocal regulation of phosphorylation and MeArg of Nav1.2 may underlie changes in neuronal Nav channel function in response to seizures and also contribute to physiological modulation of neuronal excitability.
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Affiliation(s)
- Je-Hyun Baek
- From the Department of Neurobiology, Physiology, and Behavior and
| | - Moran Rubinstein
- the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195-7280
| | - Todd Scheuer
- the Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195-7280
| | - James S Trimmer
- From the Department of Neurobiology, Physiology, and Behavior and the Department of Physiology and Membrane Biology, University of California, Davis, California 95616 and
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Yakubovich D, Berlin S, Rubinstein M, Kahanovich U, Dessauer CW, Dascal N. Preferential Association with Gβγ Over Gα Governs the Activity of a G Protein-Activated K+ Channel. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.2939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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Zhang W, Lin M, Winesett A, Dhez O, Kilcoyne ALD, Ade H, Rubinstein M, Shafi KVPM, Ulman A, Gersappe D, Tenne R, Rafailovich M, Sokolov J, Frisch HL. The use of functionalized nanoparticles as non-specific compatibilizers for polymer blends. POLYM ADVAN TECHNOL 2010. [DOI: 10.1002/pat.1875] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Thanos PK, Bermeo C, Rubinstein M, Suchland KL, Wang GJ, Grandy DK, Volkow ND. Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors. J Psychopharmacol 2010; 24:897-904. [PMID: 19282420 PMCID: PMC2878389 DOI: 10.1177/0269881109102613] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs. Thus, individuals with D4 receptor polymorphisms might show enhanced reinforcing responses to MP and AMPH and attenuated locomotor response to AMPH.
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Affiliation(s)
- P K Thanos
- Laboratory of Neuroimaging, NIAAA Intramural Program, NIH, Bethesda, MD, USA.
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Kaiser ML, Rubinstein M, Vokes DE, Ridgway JM, Guo S, Gu M, Crumley RL, Armstrong WB, Chen Z, Wong BJF. Laryngeal epithelial thickness: a comparison between optical coherence tomography and histology. Clin Otolaryngol 2010; 34:460-6. [PMID: 19793279 DOI: 10.1111/j.1749-4486.2009.02005.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Optical coherence tomography, an imaging modality using near-infrared light, produces cross-sectional tissue images with a lateral pixel resolution of 10 microm. However, normative data is first needed on epithelial thickness for lesion characterisation, and, to date, little exists. The purpose of our study is to measure normal laryngeal epithelial thickness by in vivo optical coherence tomography, and compare these values to those obtained from fixed ex-vivo laryngectomy specimens. DESIGN AND SETTING Prospective at a single medical center in California, United States. PARTICIPANTS A total of 116 patients undergoing operative endoscopy. MAIN OUTCOME MEASURES Optical coherence tomography images of clinically normal laryngeal subsites were selected. Calibrated measurements of epithelial thickness at various laryngeal subsites were recorded. Measurements of epithelial thickness from corresponding areas were obtained using optical micrometry on histologically normal regions of 15 total laryngectomy specimens. Descriptive statistics were performed. RESULTS Mean epithelial optical coherence tomography thicknesses were: true vocal cords (81 microm), false vocal cords (78 microm), subglottis (61 microm), aryepiglottic folds (111 microm), laryngeal epiglottis (116 microm) and lingual epiglottis (170 microm). Epithelial thicknesses in fixed tissues were: true vocal cords (103 microm), false vocal cords (79 microm), aryepiglottic folds (205 microm) subglottis (61 microm), laryngeal epiglottis (38 microm) and lingual epiglottis (130 microm). CONCLUSIONS Optical coherence tomography does not have the artifacts associated with conventional histologic techniques. The inevitable development of office-based optical coherence tomography devices will increase the precision of laryngeal measurements and contribute to the clinical application of this technology in diagnosing laryngeal disease.
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Affiliation(s)
- M L Kaiser
- Department of Surgery, University of California Irvine, Orange, CA 92612, USA
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Berlin S, Keren-Raifman T, Castel R, Rubinstein M, Dessauer CW, Ivanina T, Dascal N. G alpha(i) and G betagamma jointly regulate the conformations of a G betagamma effector, the neuronal G protein-activated K+ channel (GIRK). J Biol Chem 2009; 285:6179-85. [PMID: 20018875 DOI: 10.1074/jbc.m109.085944] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Stable complexes among G proteins and effectors are an emerging concept in cell signaling. The prototypical G betagamma effector G protein-activated K(+) channel (GIRK; Kir3) physically interacts with G betagamma but also with G alpha(i/o). Whether and how G alpha(i/o) subunits regulate GIRK in vivo is unclear. We studied triple interactions among GIRK subunits 1 and 2, G alpha(i3) and G betagamma. We used in vitro protein interaction assays and in vivo intramolecular Förster resonance energy transfer (i-FRET) between fluorophores attached to N and C termini of either GIRK1 or GIRK2 subunit. We demonstrate, for the first time, that G betagamma and G alpha(i3) distinctly and interdependently alter the conformational states of the heterotetrameric GIRK1/2 channel. Biochemical experiments show that G betagamma greatly enhances the binding of GIRK1 subunit to G alpha(i3)(GDP) and, unexpectedly, to G alpha(i3)(GTP). i-FRET showed that both G alpha(i3) and G betagamma induced distinct conformational changes in GIRK1 and GIRK2. Moreover, GIRK1 and GIRK2 subunits assumed unique, distinct conformations when coexpressed with a "constitutively active" G alpha(i3) mutant and G betagamma together. These conformations differ from those assumed by GIRK1 or GIRK2 after separate coexpression of either G alpha(i3) or G betagamma. Both biochemical and i-FRET data suggest that GIRK acts as the nucleator of the GIRK-G alpha-G betagamma signaling complex and mediates allosteric interactions between G alpha(i)(GTP) and G betagamma. Our findings imply that G alpha(i/o) and the G alpha(i) betagamma heterotrimer can regulate a G betagamma effector both before and after activation by neurotransmitters.
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Affiliation(s)
- Shai Berlin
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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Rubinstein M, Peleg S, Berlin S, Brass D, Keren-Raifman T, Dessauer CW, Ivanina T, Dascal N. Divergent regulation of GIRK1 and GIRK2 subunits of the neuronal G protein gated K+ channel by GalphaiGDP and Gbetagamma. J Physiol 2009; 587:3473-91. [PMID: 19470775 DOI: 10.1113/jphysiol.2009.173229] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
G protein activated K+ channels (GIRK, Kir3) are switched on by direct binding of Gbetagamma following activation of Gi/o proteins via G protein-coupled receptors (GPCRs). Although Galphai subunits do not activate GIRKs, they interact with the channels and regulate the gating pattern of the neuronal heterotetrameric GIRK1/2 channel (composed of GIRK1 and GIRK2 subunits) expressed in Xenopus oocytes. Coexpressed Galphai3 decreases the basal activity (Ibasal) and increases the extent of activation by purified or coexpressed Gbegagamma. Here we show that this regulation is exerted by the 'inactive' GDP-bound Galphai3GDP and involves the formation of Galphai3betagamma heterotrimers, by a mechanism distinct from mere sequestration of Gbetagamma 'away' from the channel. The regulation of basal and Gbetagamma-evoked current was produced by the 'constitutively inactive' mutant of Galphai3, Galphai3G203A, which strongly binds Gbetagamma, but not by the 'constitutively active' mutant, Galphai3Q204L, or by Gbetagamma-scavenging proteins. Furthermore, regulation by Galphai3G203A was unique to the GIRK1 subunit; it was not observed in homomeric GIRK2 channels. In vitro protein interaction experiments showed that purified Gbetagamma enhanced the binding of Galphai3GDP to the cytosolic domain of GIRK1, but not GIRK2. Homomeric GIRK2 channels behaved as a 'classical' Gbetagamma effector, showing low Ibasal and strong Gbetagamma-dependent activation. Expression of Galphai3G203A did not affect either Ibasal or Gbetagamma-induced activation. In contrast, homomeric GIRK1* (a pore mutant able to form functional homomeric channels) exhibited large Ibasal and was poorly activated by Gbegagamma. Expression of Galphai3GDP reduced Ibasal and restored the ability of Gbetagamma to activate GIRK1*, like in GIRK1/2. Transferring the unique distal segment of the C terminus of GIRK1 to GIRK2 rendered the latter functionally similar to GIRK1*. These results demonstrate that GIRK1 containing channels are regulated by both Galphai3GDP and Gbetagamma, while GIRK2 is a Gbetagamma-effector insensitive to Galphai3GDP.
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Affiliation(s)
- Moran Rubinstein
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
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Berlin S, Keren-Raifman T, Rubinstein M, Ivanina T, Dascal N. Both “Constitutively-active” and “Inactive” Gαi3 Mutants Interact with GIRK1/2 Heterotetramer. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.2389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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42
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Rubinstein M, Berlin S, Keren-Raifman T, Peleg S, Dessauer C, Ivanina T, Dascal N. Diverse Regulation of the Neuronal G-Protein Gated K+ Channel (GIRK), GIRK1 and GIRK2 by Gα and Gβγ. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.2388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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43
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Kelly MA, Low MJ, Rubinstein M, Phillips TJ. Role of dopamine D1-like receptors in methamphetamine locomotor responses of D2 receptor knockout mice. Genes Brain Behav 2008; 7:568-77. [PMID: 18363855 DOI: 10.1111/j.1601-183x.2008.00392.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Behavioral sensitization to psychostimulants manifests as an increased locomotor response with repeated administration. Dopamine systems are accepted to play a fundamental role in sensitization, but the role of specific dopamine receptor subtypes has not been completely defined. This study used the combination of dopamine D2 receptor-deficient mice and a D1-like antagonist to examine dopamine D1 and D2 receptor involvement in acute and sensitized locomotor responses to methamphetamine. Absence of the dopamine D2 receptor resulted in attenuation of the acute stimulant effects of methamphetamine. Mutant and wild-type mice exhibited sensitization that lasted longer within the time period of the challenge test in the mutant animals. Pretreatment with the D1-like receptor antagonist SCH 23390 produced more potent reductions in the acute and sensitized locomotor responses to methamphetamine in D2 receptor-deficient mice than in wild-type mice; however, the expression of locomotor sensitization when challenged with methamphetamine alone was equivalently attenuated by previous treatment with SCH 23390. These data suggest that dopamine D2 receptors play a key role in the acute stimulant and sensitizing effects of methamphetamine and act in concert with D1-like receptors to influence the acquisition of methamphetamine-induced behavioral sensitization, traits that may influence continued methamphetamine use.
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Affiliation(s)
- M A Kelly
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA
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44
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Kapnistos M, Lang M, Vlassopoulos D, Pyckhout-Hintzen W, Richter D, Cho D, Chang T, Rubinstein M. Unexpected power-law stress relaxation of entangled ring polymers. Nat Mater 2008; 7:997-1002. [PMID: 18953345 PMCID: PMC4819970 DOI: 10.1038/nmat2292] [Citation(s) in RCA: 369] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 09/12/2008] [Indexed: 05/03/2023]
Abstract
After many years of intense research, most aspects of the motion of entangled polymers have been understood. Long linear and branched polymers have a characteristic entanglement plateau and their stress relaxes by chain reptation or branch retraction, respectively. In both mechanisms, the presence of chain ends is essential. But how do entangled polymers without ends relax their stress? Using properly purified high-molar-mass ring polymers, we demonstrate that these materials exhibit self-similar dynamics, yielding a power-law stress relaxation. However, trace amounts of linear chains at a concentration almost two decades below their overlap cause an enhanced mechanical response. An entanglement plateau is recovered at higher concentrations of linear chains. These results constitute an important step towards solving an outstanding problem of polymer science and are useful for manipulating properties of materials ranging from DNA to polycarbonate. They also provide possible directions for tuning the rheology of entangled polymers.
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Affiliation(s)
- M Kapnistos
- FORTH, Institute of Electronic Structure and Laser, Heraklion, Crete 71110, Greece
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45
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Novick D, Elbirt D, Dinarello CA, Rubinstein M, Sthoeger ZM. Interleukin-18 binding protein in the sera of patients with Wegener's granulomatosis. J Clin Immunol 2008; 29:38-45. [PMID: 18594952 DOI: 10.1007/s10875-008-9217-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 06/05/2008] [Indexed: 12/24/2022]
Abstract
INTRODUCTION In the present study, we examined the levels of the pro-inflammatory cytokine IL-18 and its natural inhibitor, the IL-18 binding protein (IL-18BP), in sera of Wegener's granulomatosis (WG) patients at various stages of the disease. PATIENTS AND METHODS Sera from eight consecutive biopsy-proven systemic WG patients (four men and four women; age at diagnosis 58.4 +/- 13.8 years) were obtained longitudinally with a follow-up period of 55.2 +/- 30 months. Sera obtained from 50 healthy subjects were used as controls. RESULTS AND DISCUSSION Serum levels of IL-18, IL-18BP, and free IL-18 obtained during an active phase of the disease (Birmingham Vasculitis Activity Score, BVAS > 10) were more than twofold higher than levels in the same patients during inactive disease stages (BVAS < 5; P < 0.002; P < 0.006, and P < 0.03 for IL-18, IL-18BP, and free IL-18, respectively). During inactive stages, the levels of these markers were comparable to those of healthy controls. The elevated levels of IL-18 and IL-18BP in sera during active stages of disease suggest a possible role in the pathogenesis and course of the WG. CONCLUSION Despite the elevated IL-18BP levels during active disease, free IL-18 remained higher than in the inactive disease stages, suggesting a potential benefit of administration of exogenous IL-18BP as a novel therapeutic approach for active WG.
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Affiliation(s)
- D Novick
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel.
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46
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Affiliation(s)
- N. P. Shusharina
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290
| | - M. Rubinstein
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290
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47
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Moodie JJ, Masood I, Tint N, Rubinstein M, Vernon SA. Patients' attitudes towards trainee surgeons performing cataract surgery at a teaching hospital. Eye (Lond) 2007; 22:1183-6. [PMID: 17525769 DOI: 10.1038/sj.eye.6702872] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [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: 11/09/2022] Open
Abstract
AIM To evaluate patients' preferences of surgeon to perform their cataract surgery if given a choice between consultant and trainee. METHODS A questionnaire based patient satisfaction survey was conducted in a large University Teaching Hospital in the UK. One hundred and eighty patients undergoing first eye cataract surgery between January and March 2006 were asked a number of set questions on their preferences regarding the surgeon performing the operation. Primary outcome measure was the patient's preference for who would perform their cataract surgery (consultant or trainee). RESULTS Overall, 126 (70%) accepted that trainee surgeons should operate as part of their training. Only 102 (81%) of these (57% of the total) would be happy to be operated on themselves by a supervised surgical trainee. Ninety-eight (78%) patients objected to being operated on by a trainee if they were to be unsupervised. One hundred and forty-two (79%) patients stated they would choose to wait longer for their surgery if it meant that a consultant would perform their operation. This preference was held significantly more strongly among patients who had been listed for surgery from a consultant's clinic rather than from the pooled 'cataract clinic' (P=0.048). One hundred and forty-four (80%) patients thought they should be told the name and designation of the surgeon who was to perform their operation. CONCLUSIONS Patients undergoing their first cataract procedure appear to have a preference for their named consultant to perform their surgery. If 'patient choice' extends to the choice of operating surgeon, then there are clear implications for the training of future UK ophthalmologists.
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Affiliation(s)
- J J Moodie
- Department of Ophthalmology, Queen's Medical Centre, Nottingham, UK
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48
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Rubinstein M, Peleg S, Berlin S, Brass D, Dascal N. Galphai3 primes the G protein-activated K+ channels for activation by coexpressed Gbetagamma in intact Xenopus oocytes. J Physiol 2007; 581:17-32. [PMID: 17289785 PMCID: PMC2075207 DOI: 10.1113/jphysiol.2006.125864] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 02/02/2007] [Indexed: 01/29/2023] Open
Abstract
G protein-activated K+ channels (GIRK) mediate postsynaptic inhibitory effects of neurotransmitters in the atrium and in the brain by coupling to G protein-coupled receptors (GPCRs). In neurotransmitter-dependent GIRK signalling, Gbetagamma is released from the heterotrimeric Galphabetagamma complex upon GPCR activation, activating the channel and attenuating its rectification. Now it becomes clear that Galpha is more than a mere Gbetagamma donor. We have proposed that Galphai3-GDP regulates GIRK gating, keeping its basal activity low but priming (predisposing) the channel for activation by agonist in intact cells, and by Gbetagamma in excised patches. Here we have further investigated GIRK priming by Galphai3 using a model in which the channel was activated by coexpression of Gbetagamma, and the currents were measured in intact Xenopus oocytes using the two-electrode voltage clamp technique. This method enables the bypass of GPCR activation during examination of the regulation of the channel in intact cells. Using this method, we further characterize the priming phenomenon. We tested and excluded the possibility that our estimates of priming are affected by artifacts caused by series resistance or large K+ fluxes. We demonstrate that both Galphai3 and membrane-attached Gbetagamma scavenger protein, m-phosducin, reduce the basal channel activity. However, Galphai3 allows robust channel activation by coexpressed Gbetagamma, in sharp contrast to m-phosducin, which causes a substantial reduction in the total Gbetagamma-induced current. Furthermore, Galphai3 also does not impair the Gbetagamma-dependent attenuation of the channel rectification, in contrast to m-phosducin, which prevents this Gbetagamma-induced modulation. The Galphai3-induced enhancement of direct activation of GIRK by Gbetagamma, demonstrated here for the first time in intact cells, strongly supports the hypothesis that Galphai regulates GIRK gating under physiological conditions.
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Affiliation(s)
- Moran Rubinstein
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
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Werner H, Idelman G, Rubinstein M, Pattee P, Nagalla SR, Roberts CT. A novel EWS-WT1 gene fusion product in desmoplastic small round cell tumor is a potent transactivator of the insulin-like growth factor-I receptor (IGF-IR) gene. Cancer Lett 2007; 247:84-90. [PMID: 16730884 DOI: 10.1016/j.canlet.2006.03.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 03/19/2006] [Accepted: 03/24/2006] [Indexed: 10/24/2022]
Abstract
Desmoplastic small round cell tumor (DSRCT) is a primitive sarcoma characterized by a recurrent chromosomal translocation, t(11;22)(p13;q12), which fuses the 5' exons of the EWS gene to the 3' exons of the WT1 gene. EWS-WT1 chimeras are heterogeneous as a result of fusions of different regions of the EWS gene to the WT1 gene. We report here a rare and novel EWS-WT1 variant, EWS-WT1 5/10, in a 6-year-old boy diagnosed with DSRCT and analyze the potential transactivation effect of the fusion oncoprotein. The predicted product is comprised of the N-terminal transactivation domain of EWS and lacks any sequence derived from the WT1 gene product. Nonetheless, the truncated protein was able to stimulate expression of the insulin-like growth factor-I receptor gene, a potent antiapoptotic receptor tyrosine kinase with potentially important roles in DSRCT etiology. These findings raise the possibility that the oncogenic potential of EWS-WT1 fusions is not necessarily a consequence of the fusion protein product per se.
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Affiliation(s)
- Haim Werner
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel.
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Vardi A, Efrati O, Levin I, Matok I, Rubinstein M, Paret G, Barzilay Z. Prevention of potential errors in resuscitation medications orders by means of a computerised physician order entry in paediatric critical care. Resuscitation 2007; 73:400-6. [PMID: 17289249 DOI: 10.1016/j.resuscitation.2006.10.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Revised: 09/26/2006] [Accepted: 10/22/2006] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Computerised physician order entry with clinical decision support system (CPOE+CDSS) is an important tool in attempting to reduce medication errors. The objective of this study was to evaluate the impact of a CPOE+CDSS on (1) the frequency of errors in ordering resuscitation (CPR) medications and (2) the time for printing out the order form, in a paediatric critical care department (PCCD). METHODS SETTING An 18-bed PCCD in a tertiary-care children's hospital. DESIGN Prospective cohort study. MEASURES Compilation and comparison of number of errors and time to fill in forms before and after implementation of CPOE+CDSS. Time to fill in conventional, simulated and CPOE forms was measured and compared. RESULTS There were three reported incidents of errors among 13,124 CPR medications orders during the year preceding implementation of CPOE+CDSS. These represent errors that escaped the triple check by three independent staff members. There were no errors after CPOE+CDSS was implemented (100% error reduction for 46,970 orders). Time to completion of drug forms dropped from 14 min 42 s to 2 min 14s (p < 0.001). CONCLUSIONS CPOE+CDSS completely eliminated errors in filling in the forms and significantly reduced time to completing the form.
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Affiliation(s)
- A Vardi
- The Department of Pediatric Critical Care, Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer Affiliated to The Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
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