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Zhu S, Shen Z, Wu X, Han W, Jia B, Lu W, Zhang M. Demixing is a default process for biological condensates formed via phase separation. Science 2024; 384:920-928. [PMID: 38781377 DOI: 10.1126/science.adj7066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 04/15/2024] [Indexed: 05/25/2024]
Abstract
Excitatory and inhibitory synapses do not overlap even when formed on one submicron-sized dendritic protrusion. How excitatory and inhibitory postsynaptic cytomatrices or densities (e/iPSDs) are segregated is not understood. Broadly, why membraneless organelles are naturally segregated in cellular subcompartments is unclear. Using biochemical reconstitutions in vitro and in cells, we demonstrate that ePSDs and iPSDs spontaneously segregate into distinct condensed molecular assemblies through phase separation. Tagging iPSD scaffold gephyrin with a PSD-95 intrabody (dissociation constant ~4 nM) leads to mistargeting of gephyrin to ePSD condensates. Unexpectedly, formation of iPSD condensates forces the intrabody-tagged gephyrin out of ePSD condensates. Thus, instead of diffusion-governed spontaneous mixing, demixing is a default process for biomolecules in condensates. Phase separation can generate biomolecular compartmentalization specificities that cannot occur in dilute solutions.
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Affiliation(s)
- Shihan Zhu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zeyu Shen
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiandeng Wu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20824, USA
| | - Bowen Jia
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20824, USA
| | - Mingjie Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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2
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Welle TM, Rajgor D, Garcia JD, Kareemo D, Zych SM, Gookin SE, Martinez TP, Dell’Acqua ML, Ford CP, Kennedy MJ, Smith KR. miRNA-mediated control of gephyrin synthesis drives sustained inhibitory synaptic plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.570420. [PMID: 38168421 PMCID: PMC10760056 DOI: 10.1101/2023.12.12.570420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Activity-dependent protein synthesis is crucial for many long-lasting forms of synaptic plasticity. However, our understanding of the translational mechanisms controlling inhibitory synapses is limited. One distinct form of inhibitory long-term potentiation (iLTP) enhances postsynaptic clusters of GABAARs and the primary inhibitory scaffold, gephyrin, to promote sustained synaptic strengthening. While we previously found that persistent iLTP requires mRNA translation, the precise mechanisms controlling gephyrin translation during this process remain unknown. Here, we identify miR153 as a novel regulator of Gphn mRNA translation which controls gephyrin protein levels and synaptic clustering, ultimately impacting GABAergic synaptic structure and function. We find that iLTP induction downregulates miR153, reversing its translational suppression of Gphn mRNA and allowing for increased de novo gephyrin protein synthesis and synaptic clustering during iLTP. Finally, we find that reduced miR153 expression during iLTP is driven by an excitation-transcription coupling pathway involving calcineurin, NFAT and HDACs, which also controls the miRNA-dependent upregulation of GABAARs. Overall, this work delineates a miRNA-dependent post-transcriptional mechanism that controls the expression of the key synaptic scaffold, gephyrin, and may converge with parallel miRNA pathways to coordinate gene upregulation to maintain inhibitory synaptic plasticity.
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Affiliation(s)
- Theresa M. Welle
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Dipen Rajgor
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Joshua D. Garcia
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Dean Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sarah M. Zych
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sara E. Gookin
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Tyler P. Martinez
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Christopher P. Ford
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Matthew J. Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Katharine R. Smith
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
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Mendel RR, Schwarz G. The History of Animal and Plant Sulfite Oxidase-A Personal View. Molecules 2023; 28:6998. [PMID: 37836841 PMCID: PMC10574614 DOI: 10.3390/molecules28196998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/06/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023] Open
Abstract
Sulfite oxidase is one of five molybdenum-containing enzymes known in eukaryotes where it catalyzes the oxidation of sulfite to sulfate. This review covers the history of sulfite oxidase research starting out with the early years of its discovery as a hepatic mitochondrial enzyme in vertebrates, leading to basic biochemical and structural properties that have inspired research for decades. A personal view on sulfite oxidase in plants, that sulfates are assimilated for their de novo synthesis of cysteine, is presented by Ralf Mendel with numerous unexpected findings and unique properties of this single-cofactor sulfite oxidase localized to peroxisomes. Guenter Schwarz connects his research to sulfite oxidase via its deficiency in humans, demonstrating its unique role amongst all molybdenum enzymes in humans. In essence, in both the plant and animal kingdoms, sulfite oxidase represents an important player in redox regulation, signaling and metabolism, thereby connecting sulfur and nitrogen metabolism in multiple ways.
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Affiliation(s)
- Ralf R. Mendel
- Institute of Plant Biology, Technical University Braunschweig, Humboldtstrasse 1, 38106 Braunschweig, Germany
| | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry & Center for Molecular Medicine, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany;
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4
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Fan J, Dong X, Tang Y, Wang X, Lin D, Gong L, Chen C, Jiang J, Shen W, Xu A, Zhang X, Xie Y, Huang X, Zeng L. Preferential pruning of inhibitory synapses by microglia contributes to alteration of the balance between excitatory and inhibitory synapses in the hippocampus in temporal lobe epilepsy. CNS Neurosci Ther 2023; 29:2884-2900. [PMID: 37072932 PMCID: PMC10493672 DOI: 10.1111/cns.14224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 04/20/2023] Open
Abstract
BACKGROUND A consensus has formed that neural circuits in the brain underlie the pathogenesis of temporal lobe epilepsy (TLE). In particular, the synaptic excitation/inhibition balance (E/I balance) has been implicated in shifting towards elevated excitation during the development of TLE. METHODS Sprague Dawley (SD) rats were intraperitoneally subjected to kainic acid (KA) to generate a model of TLE. Next, electroencephalography (EEG) recording was applied to verify the stability and detectability of spontaneous recurrent seizures (SRS) in rats. Moreover, hippocampal slices from rats and patients with mesial temporal lobe epilepsy (mTLE) were assessed using immunofluorescence to determine the alterations of excitatory and inhibitory synapses and microglial phagocytosis. RESULTS We found that KA induced stable SRSs 14 days after status epilepticus (SE) onset. Furthermore, we discovered a continuous increase in excitatory synapses during epileptogenesis, where the total area of vesicular glutamate transporter 1 (vGluT1) rose considerably in the stratum radiatum (SR) of cornu ammonis 1 (CA1), the stratum lucidum (SL) of CA3, and the polymorphic layer (PML) of the dentate gyrus (DG). In contrast, inhibitory synapses decreased significantly, with the total area of glutamate decarboxylase 65 (GAD65) in the SL and PML diminishing enormously. Moreover, microglia conducted active synaptic phagocytosis after the formation of SRSs, especially in the SL and PML. Finally, microglia preferentially pruned inhibitory synapses during recurrent seizures in both rat and human hippocampal slices, which contributed to the synaptic alteration in hippocampal subregions. CONCLUSIONS Our findings elaborately characterize the alteration of neural circuits and demonstrate the selectivity of synaptic phagocytosis mediated by microglia in TLE, which could strengthen the comprehension of the pathogenesis of TLE and inspire potential therapeutic targets for epilepsy treatment.
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Affiliation(s)
- Jianchen Fan
- College of Pharmaceutical Sciences, Institute of Pharmacology and Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of ChinaZhejiang UniversityHangzhouChina
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of MedicineHangzhou City UniversityHangzhouChina
| | - Xinyan Dong
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Yejiao Tang
- College of Pharmaceutical Sciences, Institute of Pharmacology and Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of ChinaZhejiang UniversityHangzhouChina
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of MedicineHangzhou City UniversityHangzhouChina
| | - Xuehui Wang
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Donghui Lin
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Lifen Gong
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Chen Chen
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Jie Jiang
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Weida Shen
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of MedicineHangzhou City UniversityHangzhouChina
| | - Anyu Xu
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of MedicineHangzhou City UniversityHangzhouChina
| | - Xiangnan Zhang
- College of Pharmaceutical Sciences, Institute of Pharmacology and Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of ChinaZhejiang UniversityHangzhouChina
| | - Yicheng Xie
- Department of NeurologyThe Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child HealthHangzhouChina
| | - Xin Huang
- Department of NeurosurgeryThe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Linghui Zeng
- College of Pharmaceutical Sciences, Institute of Pharmacology and Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of ChinaZhejiang UniversityHangzhouChina
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of MedicineHangzhou City UniversityHangzhouChina
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5
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Bryson A, Reid C, Petrou S. Fundamental Neurochemistry Review: GABA A receptor neurotransmission and epilepsy: Principles, disease mechanisms and pharmacotherapy. J Neurochem 2023; 165:6-28. [PMID: 36681890 DOI: 10.1111/jnc.15769] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/12/2022] [Accepted: 01/04/2023] [Indexed: 01/23/2023]
Abstract
Epilepsy is a common neurological disorder associated with alterations of excitation-inhibition balance within brain neuronal networks. GABAA receptor neurotransmission is the most prevalent form of inhibitory neurotransmission and is strongly implicated in both the pathophysiology and treatment of epilepsy, serving as a primary target for antiseizure medications for over a century. It is now established that GABA exerts a multifaceted influence through an array of GABAA receptor subtypes that extends far beyond simply negating excitatory activity. As the role of GABAA neurotransmission within inhibitory circuits is elaborated, this will enable the development of precision therapies that correct the network dysfunction underlying epileptic pathology.
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Affiliation(s)
- Alexander Bryson
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, Austin Health, Heidelberg, Victoria, Australia
| | - Christopher Reid
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.,Praxis Precision Medicines, Inc., Cambridge, Massachusetts, USA
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6
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Complex regulation of Gephyrin splicing is a determinant of inhibitory postsynaptic diversity. Nat Commun 2022; 13:3507. [PMID: 35717442 PMCID: PMC9206673 DOI: 10.1038/s41467-022-31264-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/10/2022] [Indexed: 01/05/2023] Open
Abstract
Gephyrin (GPHN) regulates the clustering of postsynaptic components at inhibitory synapses and is involved in pathophysiology of neuropsychiatric disorders. Here, we uncover an extensive diversity of GPHN transcripts that are tightly controlled by splicing during mouse and human brain development. Proteomic analysis reveals at least a hundred isoforms of GPHN incorporated at inhibitory Glycine and gamma-aminobutyric acid A receptors containing synapses. They exhibit different localization and postsynaptic clustering properties, and altering the expression level of one isoform is sufficient to affect the number, size, and density of inhibitory synapses in cerebellar Purkinje cells. Furthermore, we discovered that splicing defects reported in neuropsychiatric disorders are carried by multiple alternative GPHN transcripts, demonstrating the need for a thorough analysis of the GPHN transcriptome in patients. Overall, we show that alternative splicing of GPHN is an important genetic variation to consider in neurological diseases and a determinant of the diversity of postsynaptic inhibitory synapses. The protein gephyrin is involved in organizing synapses. Here, the authors show how different transcripts of gephyrin form and regulate inhibitory synapses.
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7
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Rizavi HS, Chase KA, Liu C, Gavin H, Rosen C, Xia C, Guidotti A, Sharma RP. Differential H3K9me2 heterochromatin levels and concordant mRNA expression in postmortem brain tissue of individuals with schizophrenia, bipolar, and controls. Front Psychiatry 2022; 13:1006109. [PMID: 36386965 PMCID: PMC9644155 DOI: 10.3389/fpsyt.2022.1006109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
The existence of repressive and durable chromatin assemblies along gene promoters or networks, especially in the brain, is of theoretical and therapeutic relevance in a subset of individuals diagnosed with schizophrenia who experience a chronic, persistent, and treatment-resistant trajectory. We used chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) to generate an epigenomic map that includes differential sites occupied by di-methylated lysine 9 of histone 3 (H3K9me2), a repressive modification that is yet unexplored in human postmortem brain tissue. We have discovered over 150 significantly differential promoter sites in the postmortem prefrontal cortex tissue of individuals diagnosed with schizophrenia (n = 15) when compared to controls (n = 15). Potentially dysregulated gene categories include postsynaptic proteins, processing enzymes (for proproteins, lipids, and oxidative stress), cadherin family genes, the complement system, and peptide hormones. Ten genes with significantly increased or decreased H3K9me2 promoter occupation were selected through statistical analysis, function, or previous GWAS association, and Quantitative RT-PCR (qRT-PCR) was performed on an extended sample of postmortem brain tissue, adding an additional 17 controls, 7 individuals with schizophrenia, and 19 individuals with bipolar samples (n = 32 control, 22 schizophrenia, 19 bipolar). This approach revealed that mRNA expression levels correlated with chromatin modification levels in eight of 10 selected genes, and mRNA expression in the total sample could be predicted by the occupancy of H3K9me2. Utilization of this method and replication in a larger sample open a pathway to durable and restrictive epigenomic assemblies whose accumulation across the lifespan of individuals diagnosed with schizophrenia may explain treatment resistance, and advance therapeutic options.
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Affiliation(s)
- Hooriyah S Rizavi
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, Chicago, IL, United States.,Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States
| | - Kayla A Chase
- Department of Biochemistry and Molecular Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Chunyu Liu
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States.,Department of Psychiatry, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Hannah Gavin
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, Chicago, IL, United States
| | - Cherise Rosen
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, Chicago, IL, United States
| | - Cuihua Xia
- School of Life Sciences, Central South University, Changsha, China
| | - Alessandro Guidotti
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, Chicago, IL, United States
| | - Rajiv P Sharma
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, Chicago, IL, United States.,Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States
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8
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Macha A, Liebsch F, Fricke S, Hetsch F, Neuser F, Johannes L, Kress V, Djémié T, Santamaria-Araujo JA, Vilain C, Aeby A, Van Bogaert P, Dejanovic B, Weckhuysen S, Meier JC, Schwarz G. Bi-allelic gephyrin variants impair GABAergic inhibition in a patient with epileptic encephalopathy. Hum Mol Genet 2021; 31:901-913. [PMID: 34617111 DOI: 10.1093/hmg/ddab298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 11/12/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition is linked to epilepsy. Gephyrin (Geph) is the principal scaffolding protein at inhibitory synapses and is essential for postsynaptic clustering of glycine (GlyRs) and GABA type A receptors (GABAARs). Consequently, gephyrin is crucial for maintaining the relationship between excitation and inhibition in normal brain function and mutations in the gephyrin gene (GPHN) are associated with neurodevelopmental disorders and epilepsy. We identified bi-allelic variants in the GPHN gene, namely the missense mutation c.1264G > A and splice acceptor variant c.1315-2A > G, in a patient with developmental and epileptic encephalopathy (DEE). We demonstrate that the splice acceptor variant leads to nonsense-mediated mRNA decay (NMD). Furthermore, the missense variant (D422N) alters gephyrin structure, as examined by analytical size exclusion chromatography and CD-spectroscopy, thus leading to reduced receptor clustering and sensitivity towards calpain-mediated cleavage. Additionally, both alterations contribute to an observed reduction of inhibitory signal transmission in neurons, which likely contributes to the pathological encephalopathy.
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Affiliation(s)
- Arthur Macha
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Filip Liebsch
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Steffen Fricke
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Institute for Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Franziska Neuser
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Lena Johannes
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Vanessa Kress
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Tania Djémié
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium
| | - Jose A Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Catheline Vilain
- Department of Genetics, Hôpital Universitaire des Enfants Reine Fabiola, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Department of Genetics, Hôpital Erasme, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles, Brussels, Belgium
| | - Alec Aeby
- Pediatric Neurology, Queen Fabiola Children Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Patrick Van Bogaert
- Departement of Pediatric Neurology, CHU d'Angers, and Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), Université d'Angers, France
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium.,Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp, Belgium.,Neurology Department, University Hospital Antwerp, Antwerp, Belgium
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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9
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El-Tallawy HN, Abuhamdah S, Nassar AY, Farghaly WMA, Saleem TH, Atta SA, Sayed AA, Tohamy AM, Hassan MH. Gephyrin and CYP2C9 Genetic Polymorphisms in Patients with Pharmacoresistant Epilepsy. Pharmgenomics Pers Med 2021; 14:1133-1140. [PMID: 34526803 PMCID: PMC8437390 DOI: 10.2147/pgpm.s327808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 08/25/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose Gephyrin (GPHN) is an essential protein in the regulation of inhibitory postsynaptic density and polymorphism in the corresponding gene may have a role in the development of pharmacoresistant epilepsy (PRE). For the first time, we aimed to evaluate the association of rs928553T/C variants with PRE susceptibility. Moreover, we have analyzed the genetic polymorphism affecting CYP2C9 “rs12782374G/A” in the same population to detect the effect of SNP on the drug-metabolizing ability of patients with PRE. Patients and Methods This case-control study enrolled 100 patients (group A) and 100 healthy, age and sex-matched controls, unrelated to patients (group B). TaqMan™ assays using real-time PCR were run for genotyping of rs928553T/C and rs12782374G/A in all participants. Results GPHN T>C polymorphism revealed significant risk association with occurrence of PRE using dominant, recessive and codominant models as follows: TT vs (TC+CC): OR 0.23, 95%CI: 0.13–0.43, P<0.001. In addition, (TT+TC vs CC): OR 0.38, 95%CI: 0.18–0.77, P<0.001. Also, T vs C (OR 0.34, 95%CI: 0.22–0.51, P=<0.001). Similarly, CYP2C9 G>A polymorphism showed a significant increased risk of PRE (GG vs (GA+AA): OR 0.11, 95%CI: 0.05–0.23, P<0.001). Furthermore, (GG+GA vs AA): OR 0.18, 95%CI: 0.084–0.39, P<0.001. Also, G vs A (OR 0.24, 95%CI: 0.15–0.366, P=<0.001). Conclusion Mutation of both GPHN (rs928553) and CYP2C9 (rs1278237) genes may be implicated as a genetic mediators of resistance in patients with PRE.
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Affiliation(s)
- Hamdy N El-Tallawy
- Department of Neurology and Psychiatry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Sawsan Abuhamdah
- Department of Pharmaceutical Sciences, College of Pharmacy, Al Ain University, Abu Dhabi, United Arab Emirates.,Department of Biopharmaceutics and Clinical Pharmacy, Faculty of Pharmacy, University of Jordan, Amman, Jordan
| | - Ahmed Y Nassar
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Wafaa M A Farghaly
- Department of Neurology and Psychiatry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Tahia H Saleem
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Sara A Atta
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Ayat A Sayed
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Amal M Tohamy
- Department of Neurology and Psychiatry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Mohammed H Hassan
- Department of Medical Biochemistry, Faculty of Medicine, South Valley University, Qena, 83523, Egypt
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10
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The Alteration of Chloride Homeostasis/GABAergic Signaling in Brain Disorders: Could Oxidative Stress Play a Role? Antioxidants (Basel) 2021; 10:antiox10081316. [PMID: 34439564 PMCID: PMC8389245 DOI: 10.3390/antiox10081316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022] Open
Abstract
In neuronal precursors and immature neurons, the depolarizing (excitatory) effect of γ-Aminobutyric acid (GABA) signaling is associated with elevated [Cl−]i; as brain cells mature, a developmental switch occurs, leading to the decrease of [Cl−]i and to the hyperpolarizing (inhibitory) effect of GABAergic signaling. [Cl−]i is controlled by two chloride co-transporters: NKCC1, which causes Cl− to accumulate into the cells, and KCC2, which extrudes it. The ontogenetic upregulation of the latter determines the above-outlined switch; however, many other factors contribute to the correct [Cl−]i in mature neurons. The dysregulation of chloride homeostasis is involved in seizure generation and has been associated with schizophrenia, Down’s Syndrome, Autism Spectrum Disorder, and other neurodevelopmental disorders. Recently, much effort has been put into developing new drugs intended to inhibit NKCC1 activity, while no attention has been paid to the origin of [Cl−]i dysregulation. Our study examines the pathophysiology of Cl− homeostasis and focuses on the impact of oxidative stress (OS) and inflammation on the activity of Cl− co-transporters, highlighting the relevance of OS in numerous brain abnormalities and diseases. This hypothesis supports the importance of primary prevention during pregnancy. It also integrates the therapeutic framework addressed to restore normal GABAergic signaling by counteracting the alteration in chloride homeostasis in central nervous system (CNS) cells, aiming at limiting the use of drugs that potentially pose a health risk.
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11
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Bai G, Wang Y, Zhang M. Gephyrin-mediated formation of inhibitory postsynaptic density sheet via phase separation. Cell Res 2021; 31:312-325. [PMID: 33139925 PMCID: PMC8027005 DOI: 10.1038/s41422-020-00433-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 10/14/2020] [Indexed: 01/30/2023] Open
Abstract
Inhibitory synapses are also known as symmetric synapses due to their lack of prominent postsynaptic densities (PSDs) under a conventional electron microscope (EM). Recent cryo-EM tomography studies indicated that inhibitory synapses also contain PSDs, albeit with a rather thin sheet-like structure. It is not known how such inhibitory PSD (iPSD) sheet might form. Here, we demonstrate that the key inhibitory synapse scaffold protein gephyrin, when in complex with either glycine or GABAA receptors, spontaneously forms highly condensed molecular assemblies via phase separation both in solution and on supported membrane bilayers. Multivalent and specific interactions between the dimeric E-domain of gephyrin and the glycine/GABAA receptor multimer are essential for the iPSD condensate formation. Gephyrin alone does not form condensates. The linker between the G- and E-domains of gephyrin inhibits the iPSD condensate formation via autoinhibition. Phosphorylation of specific residues in the linker or binding of target proteins such as dynein light chain to the linker domain regulates gephyrin-mediated glycine/GABAA receptor clustering. Thus, analogous to excitatory PSDs, iPSDs are also formed by phase separation-mediated condensation of scaffold protein/neurotransmitter receptor complexes.
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Affiliation(s)
- Guanhua Bai
- grid.24515.370000 0004 1937 1450Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Yu Wang
- grid.24515.370000 0004 1937 1450Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Mingjie Zhang
- grid.24515.370000 0004 1937 1450Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China ,grid.24515.370000 0004 1937 1450Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
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12
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Kim S, Kang M, Park D, Lee AR, Betz H, Ko J, Chang I, Um JW. Impaired formation of high-order gephyrin oligomers underlies gephyrin dysfunction-associated pathologies. iScience 2021; 24:102037. [PMID: 33532714 PMCID: PMC7822942 DOI: 10.1016/j.isci.2021.102037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/01/2020] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Gephyrin is critical for the structure, function, and plasticity of inhibitory synapses. Gephyrin mutations have been linked to various neurological disorders; however, systematic analyses of the functional consequences of these mutations are lacking. Here, we performed molecular dynamics simulations of gephyrin to predict how six reported point mutations might change the structural stability and/or function of gephyrin. Additional in silico analyses revealed that the A91T and G375D mutations reduce the binding free energy of gephyrin oligomer formation. Gephyrin A91T and G375D displayed altered clustering patterns in COS-7 cells and nullified the inhibitory synapse-promoting effect of gephyrin in cultured neurons. However, only the G375D mutation reduced gephyrin interaction with GABAA receptors and neuroligin-2 in mouse brain; it also failed to normalize deficits in GABAergic synapse maintenance and neuronal hyperactivity observed in hippocampal dentate gyrus-specific gephyrin-deficient mice. Our results provide insights into biochemical, cell-biological, and network-activity effects of the pathogenic G375D mutation.
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Affiliation(s)
- Seungjoon Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Mooseok Kang
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.,Core Protein Resources Center, DGIST, Daegu 42988, Korea
| | - Dongseok Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Ae-Ree Lee
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.,Core Protein Resources Center, DGIST, Daegu 42988, Korea
| | - Heinrich Betz
- Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Iksoo Chang
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.,Core Protein Resources Center, DGIST, Daegu 42988, Korea.,Supercomputing Bigdata Center, DGIST, Daegu 42988, Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.,Core Protein Resources Center, DGIST, Daegu 42988, Korea
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13
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Schulte C, Khayenko V, Nordblom NF, Tippel F, Peck V, Gupta AJ, Maric HM. High-throughput determination of protein affinities using unmodified peptide libraries in nanomolar scale. iScience 2021; 24:101898. [PMID: 33364586 PMCID: PMC7753147 DOI: 10.1016/j.isci.2020.101898] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/13/2020] [Accepted: 12/01/2020] [Indexed: 12/02/2022] Open
Abstract
Protein-protein interactions (PPIs) are of fundamental importance for our understanding of physiology and pathology. PPIs involving short, linear motifs play a major role in immunological recognition, signaling, and regulation and provide attractive starting points for pharmaceutical intervention. Yet, state-of-the-art protein-peptide affinity determination approaches exhibit limited throughput and sensitivity, often resulting from ligand immobilization, labeling, or synthesis. Here, we introduce a high-throughput method for in-solution analysis of protein-peptide interactions using a phenomenon called temperature related intensity change (TRIC). We use TRIC for the identification and fine-mapping of low- and high-affinity protein interaction sites and the definition of sequence binding requirements. Validation is achieved by microarray-based studies using wild-type and mutated recombinant protein and the native protein within tissue lysates. On-chip neutralization and strong correlation with structural data establish TRIC as a quasi-label-free method to determine binding affinities of unmodified peptide libraries with large dynamic range.
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Affiliation(s)
- Clemens Schulte
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Vladimir Khayenko
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Noah Frieder Nordblom
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Franziska Tippel
- Nanotemper Technologies GmbH, Flößergasse 4, 81369 Munich, Germany
| | - Violetta Peck
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Amit Jean Gupta
- Nanotemper Technologies GmbH, Flößergasse 4, 81369 Munich, Germany
| | - Hans Michael Maric
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
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14
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Mayr SJ, Mendel RR, Schwarz G. Molybdenum cofactor biology, evolution and deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118883. [PMID: 33017596 DOI: 10.1016/j.bbamcr.2020.118883] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022]
Abstract
The molybdenum cofactor (Moco) represents an ancient metal‑sulfur cofactor, which participates as catalyst in carbon, nitrogen and sulfur cycles, both on individual and global scale. Given the diversity of biological processes dependent on Moco and their evolutionary age, Moco is traced back to the last universal common ancestor (LUCA), while Moco biosynthetic genes underwent significant changes through evolution and acquired additional functions. In this review, focused on eukaryotic Moco biology, we elucidate the benefits of gene fusions on Moco biosynthesis and beyond. While originally the gene fusions were driven by biosynthetic advantages such as coordinated expression of functionally related proteins and product/substrate channeling, they also served as origin for the development of novel functions. Today, Moco biosynthetic genes are involved in a multitude of cellular processes and loss of the according gene products result in severe disorders, both related to Moco biosynthesis and secondary enzyme functions.
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Affiliation(s)
- Simon J Mayr
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine, University of Cologne, Zuelpicher Str. 47, 50674 Koeln, Germany
| | - Ralf-R Mendel
- Institute of Plant Biology, Braunschweig University of Technology, Humboldtstr. 1, 38106 Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine, University of Cologne, Zuelpicher Str. 47, 50674 Koeln, Germany.
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15
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Pizzarelli R, Griguoli M, Zacchi P, Petrini EM, Barberis A, Cattaneo A, Cherubini E. Tuning GABAergic Inhibition: Gephyrin Molecular Organization and Functions. Neuroscience 2020; 439:125-136. [PMID: 31356900 PMCID: PMC7351109 DOI: 10.1016/j.neuroscience.2019.07.036] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 01/15/2023]
Abstract
To be highly reliable, synaptic transmission needs postsynaptic receptors (Rs) in precise apposition to the presynaptic release sites. At inhibitory synapses, the postsynaptic protein gephyrin self-assembles to form a scaffold that anchors glycine and GABAARs to the cytoskeleton, thus ensuring the accurate accumulation of postsynaptic receptors at the right place. This protein undergoes several post-translational modifications which control protein-protein interaction and downstream signaling pathways. In addition, through the constant exchange of scaffolding elements and receptors in and out of synapses, gephyrin dynamically regulates synaptic strength and plasticity. The aim of the present review is to highlight recent findings on the functional role of gephyrin at GABAergic inhibitory synapses. We will discuss different approaches used to interfere with gephyrin in order to unveil its function. In addition, we will focus on the impact of gephyrin structure and distribution at the nanoscale level on the functional properties of inhibitory synapses as well as the implications of this scaffold protein in synaptic plasticity processes. Finally, we will emphasize how gephyrin genetic mutations or alterations in protein expression levels are implicated in several neuropathological disorders, including autism spectrum disorders, schizophrenia, temporal lobe epilepsy and Alzheimer's disease, all associated with severe deficits of GABAergic signaling. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.
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Affiliation(s)
- Rocco Pizzarelli
- European Brain Research Institute (EBRI), Fondazione Rita Levi-Montalcini, Roma, Italy
| | - Marilena Griguoli
- European Brain Research Institute (EBRI), Fondazione Rita Levi-Montalcini, Roma, Italy
| | - Paola Zacchi
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Enrica Maria Petrini
- Fondazione Istituto Italiano di Tecnologia (IIT), Department of Neuroscience and Brain Technologies, Plasticity of inhibitory networks Unit, Genoa, Italy
| | - Andrea Barberis
- Fondazione Istituto Italiano di Tecnologia (IIT), Department of Neuroscience and Brain Technologies, Plasticity of inhibitory networks Unit, Genoa, Italy
| | - Antonino Cattaneo
- European Brain Research Institute (EBRI), Fondazione Rita Levi-Montalcini, Roma, Italy; Scuola Normale Superiore, Pisa, Italy
| | - Enrico Cherubini
- European Brain Research Institute (EBRI), Fondazione Rita Levi-Montalcini, Roma, Italy; Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy.
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16
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Kasaragod VB, Schindelin H. Structure of Heteropentameric GABA A Receptors and Receptor-Anchoring Properties of Gephyrin. Front Mol Neurosci 2019; 12:191. [PMID: 31440140 PMCID: PMC6693554 DOI: 10.3389/fnmol.2019.00191] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/22/2019] [Indexed: 12/20/2022] Open
Abstract
γ-Aminobutyric acid type A receptors (GABAARs) mediate the majority of fast synaptic inhibition in the central nervous system (CNS). GABAARs belong to the Cys-loop superfamily of pentameric ligand-gated ion channels (pLGIC) and are assembled from 19 different subunits. As dysfunctional GABAergic neurotransmission manifests itself in neurodevelopmental disorders including epilepsy and anxiety, GABAARs are key drug targets. The majority of synaptic GABAARs are anchored at the inhibitory postsynaptic membrane by the principal scaffolding protein gephyrin, which acts as the central organizer in maintaining the architecture of the inhibitory postsynaptic density (iPSD). This interaction is mediated by the long intracellular loop located in between transmembrane helices 3 and 4 (M3–M4 loop) of the receptors and a universal receptor-binding pocket residing in the C-terminal domain of gephyrin. In 2014, the crystal structure of the β3-homopentameric GABAAR provided crucial information regarding the architecture of the receptor; however, an understanding of the structure and assembly of heteropentameric receptors at the atomic level was lacking. This review article will highlight recent advances in understanding the structure of heteropentameric synaptic GABAARs and how these structures have provided fundamental insights into the assembly of these multi-subunit receptors as well as their modulation by diverse ligands including the physiological agonist GABA. We will further discuss the role of gephyrin in the anchoring of synaptic GABAARs and glycine receptors (GlyRs), which are crucial for maintaining the architecture of the iPSD. Finally, we will also summarize how anti-malarial artemisinin drugs modulate gephyrin-mediated inhibitory neurotransmission.
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Affiliation(s)
- Vikram Babu Kasaragod
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Hermann Schindelin
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
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17
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Kasaragod VB, Hausrat TJ, Schaefer N, Kuhn M, Christensen NR, Tessmer I, Maric HM, Madsen KL, Sotriffer C, Villmann C, Kneussel M, Schindelin H. Elucidating the Molecular Basis for Inhibitory Neurotransmission Regulation by Artemisinins. Neuron 2019; 101:673-689.e11. [DOI: 10.1016/j.neuron.2019.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 10/11/2018] [Accepted: 12/27/2018] [Indexed: 02/06/2023]
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18
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Guang S, Pang N, Deng X, Yang L, He F, Wu L, Chen C, Yin F, Peng J. Synaptopathology Involved in Autism Spectrum Disorder. Front Cell Neurosci 2018; 12:470. [PMID: 30627085 PMCID: PMC6309163 DOI: 10.3389/fncel.2018.00470] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/19/2018] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorder (ASD) encompasses a group of multifactorial neurodevelopmental disorders characterized by impaired social communication, social interaction and repetitive behaviors. ASD affects 1 in 59 children, and is about 4 times more common among boys than among girls. Strong genetic components, together with environmental factors in the early stage of development, contribute to the pathogenesis of ASD. Multiple studies have revealed that mutations in genes like NRXN, NLGN, SHANK, TSC1/2, FMR1, and MECP2 converge on common cellular pathways that intersect at synapses. These genes encode cell adhesion molecules, scaffolding proteins and proteins involved in synaptic transcription, protein synthesis and degradation, affecting various aspects of synapses including synapse formation and elimination, synaptic transmission and plasticity. This suggests that the pathogenesis of ASD may, at least in part, be attributed to synaptic dysfunction. In this article, we will review major genes and signaling pathways implicated in synaptic abnormalities underlying ASD, and discuss molecular, cellular and functional studies of ASD experimental models.
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Affiliation(s)
- Shiqi Guang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Xiaolu Deng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Liwen Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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19
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Groeneweg FL, Trattnig C, Kuhse J, Nawrotzki RA, Kirsch J. Gephyrin: a key regulatory protein of inhibitory synapses and beyond. Histochem Cell Biol 2018; 150:489-508. [DOI: 10.1007/s00418-018-1725-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2018] [Indexed: 12/26/2022]
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20
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Kasaragod VB, Schindelin H. Structure-Function Relationships of Glycine and GABA A Receptors and Their Interplay With the Scaffolding Protein Gephyrin. Front Mol Neurosci 2018; 11:317. [PMID: 30258351 PMCID: PMC6143783 DOI: 10.3389/fnmol.2018.00317] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/16/2018] [Indexed: 12/03/2022] Open
Abstract
Glycine and γ-aminobutyric acid (GABA) are the major determinants of inhibition in the central nervous system (CNS). These neurotransmitters target glycine and GABAA receptors, respectively, which both belong to the Cys-loop superfamily of pentameric ligand-gated ion channels (pLGICs). Interactions of the neurotransmitters with the cognate receptors result in receptor opening and a subsequent influx of chloride ions, which, in turn, leads to hyperpolarization of the membrane potential, thus counteracting excitatory stimuli. The majority of glycine receptors and a significant fraction of GABAA receptors (GABAARs) are recruited and anchored to the post-synaptic membrane by the central scaffolding protein gephyrin. This ∼93 kDa moonlighting protein is structurally organized into an N-terminal G-domain (GephG) connected to a C-terminal E-domain (GephE) via a long unstructured linker. Both inhibitory neurotransmitter receptors interact via a short peptide motif located in the large cytoplasmic loop located in between transmembrane helices 3 and 4 (TM3-TM4) of the receptors with a universal receptor-binding epitope residing in GephE. Gephyrin engages in nearly identical interactions with the receptors at the N-terminal end of the peptide motif, and receptor-specific interaction toward the C-terminal region of the peptide. In addition to its receptor-anchoring function, gephyrin also interacts with a rather large collection of macromolecules including different cytoskeletal elements, thus acting as central scaffold at inhibitory post-synaptic specializations. Dysfunctions in receptor-mediated or gephyrin-mediated neurotransmission have been identified in various severe neurodevelopmental disorders. Although biochemical, cellular and electrophysiological studies have helped to understand the physiological and pharmacological roles of the receptors, recent high resolution structures of the receptors have strengthened our understanding of the receptors and their gating mechanisms. Besides that, multiple crystal structures of GephE in complex with receptor-derived peptides have shed light into receptor clustering by gephyrin at inhibitory post-synapses. This review will highlight recent biochemical and structural insights into gephyrin and the GlyRs as well as GABAA receptors, which provide a deeper understanding of the molecular machinery mediating inhibitory neurotransmission.
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Affiliation(s)
- Vikram B Kasaragod
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Hermann Schindelin
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
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21
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Hines RM, Maric HM, Hines DJ, Modgil A, Panzanelli P, Nakamura Y, Nathanson AJ, Cross A, Deeb T, Brandon NJ, Davies P, Fritschy JM, Schindelin H, Moss SJ. Developmental seizures and mortality result from reducing GABA A receptor α2-subunit interaction with collybistin. Nat Commun 2018; 9:3130. [PMID: 30087324 PMCID: PMC6081406 DOI: 10.1038/s41467-018-05481-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 07/05/2018] [Indexed: 01/08/2023] Open
Abstract
Fast inhibitory synaptic transmission is mediated by γ-aminobutyric acid type A receptors (GABAARs) that are enriched at functionally diverse synapses via mechanisms that remain unclear. Using isothermal titration calorimetry and complementary methods we demonstrate an exclusive low micromolar binding of collybistin to the α2-subunit of GABAARs. To explore the biological relevance of collybistin-α2-subunit selectivity, we generate mice with a mutation in the α2-subunit-collybistin binding region (Gabra2-1). The mutation results in loss of a distinct subset of inhibitory synapses and decreased amplitude of inhibitory synaptic currents. Gabra2-1 mice have a striking phenotype characterized by increased susceptibility to seizures and early mortality. Surviving Gabra2-1 mice show anxiety and elevations in electroencephalogram δ power, which are ameliorated by treatment with the α2/α3-selective positive modulator, AZD7325. Taken together, our results demonstrate an α2-subunit selective binding of collybistin, which plays a key role in patterned brain activity, particularly during development.
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Affiliation(s)
- Rochelle M Hines
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA.
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, 89154, Ne, USA.
| | - Hans Michael Maric
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, D-97080, Germany
- Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Würzburg, D-97080, Germany
| | - Dustin J Hines
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, 89154, Ne, USA
| | - Amit Modgil
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
| | - Patrizia Panzanelli
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, 10126, Italy
| | - Yasuko Nakamura
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
| | - Anna J Nathanson
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
| | - Alan Cross
- AstraZeneca Neuroscience iMED, Biotech Unit, Boston, 02451, MA, USA
| | - Tarek Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, 02111, MA, USA
| | - Nicholas J Brandon
- AstraZeneca Neuroscience iMED, Biotech Unit, Boston, 02451, MA, USA
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, 02111, MA, USA
| | - Paul Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA
| | - Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, 8057, Switzerland
- Center for Neuroscience Zurich, University of Zurich and ETH Zurich, Zurich, 8057, Switzerland
| | - Hermann Schindelin
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, D-97080, Germany
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, 02111, MA, USA.
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, 02111, MA, USA.
- Department of Neuroscience, Physiology and Pharmacology, University College, London, WC1E 6BT, UK.
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22
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Pozzi D, Menna E, Canzi A, Desiato G, Mantovani C, Matteoli M. The Communication Between the Immune and Nervous Systems: The Role of IL-1β in Synaptopathies. Front Mol Neurosci 2018; 11:111. [PMID: 29674955 PMCID: PMC5895746 DOI: 10.3389/fnmol.2018.00111] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/20/2018] [Indexed: 12/14/2022] Open
Abstract
In the last 15 years, groundbreaking genetic progress has underlined a convergence onto coherent synaptic pathways for most psychiatric and neurodevelopmental disorders, which are now collectively called “synaptopathies.” However, the modest size of inheritance detected so far indicates a multifactorial etiology for these disorders, underlining the key contribution of environmental effects to them. Inflammation is known to influence the risk and/or severity of a variety of synaptopathies. In particular, pro-inflammatory cytokines, produced and released in the brain by activated astrocytes and microglia, may play a pivotal role in these pathologies. Although the link between immune system activation and defects in cognitive processes is nowadays clearly established, the knowledge of the molecular mechanisms by which inflammatory mediators specifically hit synaptic components implicated in synaptopathies is still in its infancy. This review summarizes recent evidence showing that the pro-inflammatory cytokine interleukin-1β (IL-1β) specifically targets synaptopathy molecular substrate, leading to memory defects and pathological processes. In particular, we describe three specific pathways through which IL-1β affects (1) synaptic maintenance/dendritic complexity, (2) spine morphology, and (3) the excitatory/inhibitory balance. We coin the term immune synaptopathies to identify this class of diseases.
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Affiliation(s)
- Davide Pozzi
- Department of Biomedical Sciences, Humanitas University, Rozzano, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Elisabetta Menna
- Humanitas Clinical and Research Center, Rozzano, Italy.,Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Alice Canzi
- Department of Biomedical Sciences, Humanitas University, Rozzano, Italy
| | - Genni Desiato
- Humanitas Clinical and Research Center, Rozzano, Italy.,School of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy
| | | | - Michela Matteoli
- Humanitas Clinical and Research Center, Rozzano, Italy.,Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Milan, Italy
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23
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Sequences Flanking the Gephyrin-Binding Site of GlyRβ Tune Receptor Stabilization at Synapses. eNeuro 2018; 5:eN-NWR-0042-17. [PMID: 29464196 PMCID: PMC5818551 DOI: 10.1523/eneuro.0042-17.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 12/26/2017] [Accepted: 01/15/2018] [Indexed: 12/18/2022] Open
Abstract
The efficacy of synaptic transmission is determined by the number of neurotransmitter receptors at synapses. Their recruitment depends upon the availability of postsynaptic scaffolding molecules that interact with specific binding sequences of the receptor. At inhibitory synapses, gephyrin is the major scaffold protein that mediates the accumulation of heteromeric glycine receptors (GlyRs) via the cytoplasmic loop in the β-subunit (β-loop). This binding involves high- and low-affinity interactions, but the molecular mechanism of this bimodal binding and its implication in GlyR stabilization at synapses remain unknown. We have approached this question using a combination of quantitative biochemical tools and high-density single molecule tracking in cultured rat spinal cord neurons. The high-affinity binding site could be identified and was shown to rely on the formation of a 310-helix C-terminal to the β-loop core gephyrin-binding motif. This site plays a structural role in shaping the core motif and represents the major contributor to the synaptic confinement of GlyRs by gephyrin. The N-terminal flanking sequence promotes lower affinity interactions by occupying newly identified binding sites on gephyrin. Despite its low affinity, this binding site plays a modulatory role in tuning the mobility of the receptor. Together, the GlyR β-loop sequences flanking the core-binding site differentially regulate the affinity of the receptor for gephyrin and its trapping at synapses. Our experimental approach thus bridges the gap between thermodynamic aspects of receptor-scaffold interactions and functional receptor stabilization at synapses in living cells.
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24
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Wang Y, Ji T, Nelson AD, Glanowska K, Murphy GG, Jenkins PM, Parent JM. Critical roles of αII spectrin in brain development and epileptic encephalopathy. J Clin Invest 2018; 128:760-773. [PMID: 29337302 DOI: 10.1172/jci95743] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/28/2017] [Indexed: 12/26/2022] Open
Abstract
The nonerythrocytic α-spectrin-1 (SPTAN1) gene encodes the cytoskeletal protein αII spectrin. Mutations in SPTAN1 cause early infantile epileptic encephalopathy type 5 (EIEE5); however, the role of αII spectrin in neurodevelopment and EIEE5 pathogenesis is unknown. Prior work suggests that αII spectrin is absent in the axon initial segment (AIS) and contributes to a diffusion barrier in the distal axon. Here, we have shown that αII spectrin is expressed ubiquitously in rodent and human somatodendritic and axonal domains. CRISPR-mediated deletion of Sptan1 in embryonic rat forebrain by in utero electroporation caused altered dendritic and axonal development, loss of the AIS, and decreased inhibitory innervation. Overexpression of human EIEE5 mutant SPTAN1 in embryonic rat forebrain and mouse hippocampal neurons led to similar developmental defects that were also observed in EIEE5 patient-derived neurons. Additionally, patient-derived neurons displayed aggregation of spectrin complexes. Taken together, these findings implicate αII spectrin in critical aspects of dendritic and axonal development and synaptogenesis, and support a dominant-negative mechanism of SPTAN1 mutations in EIEE5.
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Affiliation(s)
| | | | | | | | - Geoffrey G Murphy
- Molecular and Behavioral Neuroscience Institute.,Department of Molecular and Integrative Physiology, and
| | - Paul M Jenkins
- Department of Pharmacology.,Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Jack M Parent
- Department of Neurology.,Ann Arbor VA Healthcare System, Ann Arbor, Michigan, USA
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25
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Kumar A, Dejanovic B, Hetsch F, Semtner M, Fusca D, Arjune S, Santamaria-Araujo JA, Winkelmann A, Ayton S, Bush AI, Kloppenburg P, Meier JC, Schwarz G, Belaidi AA. S-sulfocysteine/NMDA receptor-dependent signaling underlies neurodegeneration in molybdenum cofactor deficiency. J Clin Invest 2017; 127:4365-4378. [PMID: 29106383 DOI: 10.1172/jci89885] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/26/2017] [Indexed: 02/06/2023] Open
Abstract
Molybdenum cofactor deficiency (MoCD) is an autosomal recessive inborn error of metabolism characterized by neurodegeneration and death in early childhood. The rapid and progressive neurodegeneration in MoCD presents a major clinical challenge and may relate to the poor understanding of the molecular mechanisms involved. Recently, we reported that treating patients with cyclic pyranopterin monophosphate (cPMP) is a successful therapy for a subset of infants with MoCD and prevents irreversible brain damage. Here, we studied S-sulfocysteine (SSC), a structural analog of glutamate that accumulates in the plasma and urine of patients with MoCD, and demonstrated that it acts as an N-methyl D-aspartate receptor (NMDA-R) agonist, leading to calcium influx and downstream cell signaling events and neurotoxicity. SSC treatment activated the protease calpain, and calpain-dependent degradation of the inhibitory synaptic protein gephyrin subsequently exacerbated SSC-mediated excitotoxicity and promoted loss of GABAergic synapses. Pharmacological blockade of NMDA-R, calcium influx, or calpain activity abolished SSC and glutamate neurotoxicity in primary murine neurons. Finally, the NMDA-R antagonist memantine was protective against the manifestation of symptoms in a tungstate-induced MoCD mouse model. These findings demonstrate that SSC drives excitotoxic neurodegeneration in MoCD and introduce NMDA-R antagonists as potential therapeutics for this fatal disease.
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Affiliation(s)
- Avadh Kumar
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Florian Hetsch
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Marcus Semtner
- Cellular Neurosciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Debora Fusca
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Sita Arjune
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Jose Angel Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Aline Winkelmann
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany.,Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Scott Ayton
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley I Bush
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Peter Kloppenburg
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jochen C Meier
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Abdel Ali Belaidi
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
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26
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Xu X, Shangguan Y, Lu S, Wang W, Du C, Xiao F, Hu Y, Luo J, Wang L, He C, Yang Y, Zhang Y, Lu X, Yang Q, Wang X. Tubulin β-III modulates seizure activity in epilepsy. J Pathol 2017; 242:297-308. [PMID: 28378416 DOI: 10.1002/path.4903] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 03/14/2017] [Accepted: 03/27/2017] [Indexed: 11/09/2022]
Abstract
Tubulin β-III (TUBB3) is the most dynamic β-tubulin isoform expressed in neurons, and is highly expressed in the central nervous system. However, the relationship between TUBB3 and epileptic seizures has not been thoroughly investigated. The aims of this study were to investigate the expression of TUBB3 in patients with temporal lobe epilepsy and two different rat models of chronic epilepsy, and to determine the specific roles of TUBB3 in epilepsy. TUBB3 expression was upregulated in human and rat epileptic tissue. Moreover, TUBB3 expression was associated with inhibitory GABAergic neurons and the inhibitory postsynaptic scaffold protein gephyrin. TUBB3 downregulation attenuated the behavioural phenotypes of epileptic seizures during the pilocarpine-induced chronic phase of epileptic seizures and the pentylenetetrazole kindling process, whereas TUBB3 overexpression had the opposite effect. Whole-cell clamp recordings and western blotting revealed that the amplitude of GABA-A receptor-mediated miniature inhibitory postsynaptic currents and the surface expression of the GABA-A receptor were increased in rats in which TUBB3 expression was downregulated. Importantly, TUBB3 interacted with GABA-A receptor-associated protein, which is known to be involved in GABA-A receptor trafficking. These results indicate that TUBB3 plays a critical role in the regulation of epileptic seizures via GABA-A receptor trafficking, suggesting a molecular mechanism for new therapeutic strategies. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Xin Xu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Yafei Shangguan
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Shanshan Lu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Wei Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Chao Du
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Fei Xiao
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Yida Hu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Jing Luo
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Liang Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Changlong He
- Institute of Infectious Diseases, Southwest Hospital, Third Military Medical University, Chongqing, PR China
| | - Yong Yang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Yanke Zhang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Xi Lu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Qin Yang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China
| | - Xuefeng Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, PR China.,Centre of Epilepsy, Beijing Institute for Brain Disorders, Beijing, PR China
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27
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Maric HM, Hausrat TJ, Neubert F, Dalby NO, Doose S, Sauer M, Kneussel M, Strømgaard K. Gephyrin-binding peptides visualize postsynaptic sites and modulate neurotransmission. Nat Chem Biol 2016; 13:153-160. [DOI: 10.1038/nchembio.2246] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 09/15/2016] [Indexed: 11/09/2022]
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28
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Dejanovic B, Djémié T, Grünewald N, Suls A, Kress V, Hetsch F, Craiu D, Zemel M, Gormley P, Lal D, Myers CT, Mefford HC, Palotie A, Helbig I, Meier JC, De Jonghe P, Weckhuysen S, Schwarz G. Simultaneous impairment of neuronal and metabolic function of mutated gephyrin in a patient with epileptic encephalopathy. EMBO Mol Med 2016; 7:1580-94. [PMID: 26613940 PMCID: PMC4693503 DOI: 10.15252/emmm.201505323] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition plays an important role in neurological disorders. Gephyrin is a central player at inhibitory postsynapses, directly binds and organizes GABAA and glycine receptors (GABAARs and GlyRs), and is thereby indispensable for normal inhibitory neurotransmission. Additionally, gephyrin catalyzes the synthesis of the molybdenum cofactor (MoCo) in peripheral tissue. We identified a de novo missense mutation (G375D) in the gephyrin gene (GPHN) in a patient with epileptic encephalopathy resembling Dravet syndrome. Although stably expressed and correctly folded, gephyrin‐G375D was non‐synaptically localized in neurons and acted dominant‐negatively on the clustering of wild‐type gephyrin leading to a marked decrease in GABAAR surface expression and GABAergic signaling. We identified a decreased binding affinity between gephyrin‐G375D and the receptors, suggesting that Gly375 is essential for gephyrin–receptor complex formation. Surprisingly, gephyrin‐G375D was also unable to synthesize MoCo and activate MoCo‐dependent enzymes. Thus, we describe a missense mutation that affects both functions of gephyrin and suggest that the identified defect at GABAergic synapses is the mechanism underlying the patient's severe phenotype.
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Affiliation(s)
- Borislav Dejanovic
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Tania Djémié
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Nora Grünewald
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Arvid Suls
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium GENOMED, Center for Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Vanessa Kress
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Dana Craiu
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Matthew Zemel
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Padhraig Gormley
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis Lal
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | | | - Candace T Myers
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Aarno Palotie
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Program in Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein Christian Albrechts University, Kiel, Germany Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Peter De Jonghe
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Sarah Weckhuysen
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Inserm U 1127 CNRS UMR 7225 Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Institut du Cerveau et de la Moelle épinière, ICM, Paris, France Centre de reference épilepsies rares, Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière, F-75013, Paris, France
| | - Guenter Schwarz
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany
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29
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Schwarz G. Molybdenum cofactor and human disease. Curr Opin Chem Biol 2016; 31:179-87. [DOI: 10.1016/j.cbpa.2016.03.016] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/22/2016] [Accepted: 03/22/2016] [Indexed: 11/27/2022]
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30
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Preikšaitienė E, Ambrozaitytė L, Maldžienė Ž, Morkūnienė A, Cimbalistienė L, Rančelis T, Utkus A, Kučinskas V. Identification of genetic causes of congenital neurodevelopmental disorders using genome wide molecular technologies. Acta Med Litu 2016; 23:73-85. [PMID: 28356794 PMCID: PMC5088740 DOI: 10.6001/actamedica.v23i2.3324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background. Intellectual disability affects about 1–2% of the general population worldwide, and this is the leading socio-economic problem of health care. The evaluation of the genetic causes of intellectual disability is challenging because these conditions are genetically heterogeneous with many different genetic alterations resulting in clinically indistinguishable phenotypes. Genome wide molecular technologies are effective in a research setting for establishing the new genetic basis of a disease. We describe the first Lithuanian experience in genome-wide CNV detection and whole exome sequencing, presenting the results obtained in the research project UNIGENE. Materials and methods. The patients with developmental delay/intellectual disability have been investigated (n = 66). Diagnostic screening was performed using array-CGH technology. FISH and real time-PCR were used for the confirmation of gene-dose imbalances and investigation of parental samples. Whole exome sequencing using the next generation high throughput NGS technique was used to sequence the samples of 12 selected families. Results. 14 out of 66 patients had pathogenic copy number variants, and one patient had novel likely pathogenic aberration (microdeletion at 4p15.2). Twelve families have been processed for whole exome sequencing. Two identified sequence variants could be classified as pathogenic (in MECP2, CREBBP genes). The other families had several candidate intellectual disability gene variants that are of unclear clinical significance and must be further investigated for possible effect on the molecular pathways of intellectual disability. Conclusions. The genetic heterogeneity of intellectual disability requires genome wide approaches, including detection of chromosomal aberrations by chromosomal microarrays and whole exome sequencing capable of uncovering single gene mutations. This study demonstrates the benefits and challenges that accompany the use of genome wide molecular technologies and provides genotype-phenotype information on 32 patients with chromosomal imbalances and ID candidate sequence variants.
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Affiliation(s)
- Eglė Preikšaitienė
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Laima Ambrozaitytė
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Živilė Maldžienė
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Aušra Morkūnienė
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Loreta Cimbalistienė
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Tautvydas Rančelis
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Algirdas Utkus
- Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
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