1
|
Jahncke JN, Schnell E, Wright KM. Distinct functional domains of Dystroglycan regulate inhibitory synapse formation and maintenance in cerebellar Purkinje cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.29.610348. [PMID: 39257744 PMCID: PMC11383678 DOI: 10.1101/2024.08.29.610348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Dystroglycan is a cell adhesion molecule that localizes to synapses throughout the nervous system. While Dystroglycan is required to maintain inhibitory synapses from cerebellar molecular layer interneurons (MLIs) onto Purkinje cells (PCs) whether initial synaptogenesis during development is dependent on Dystroglycan has not been examined. We show that conditional deletion of Dystroglycan from Purkinje cells prior to synaptogenesis results in impaired MLI:PC synapse formation and function due to reduced presynaptic inputs and abnormal postsynaptic GABA A receptor clustering. Using genetic manipulations that disrupt glycosylation of Dystroglycan or truncate its cytoplasmic domain, we show that Dystroglycan's role in synapse function requires both extracellular and intracellular interactions, whereas synapse formation requires only extracellular interactions. Together, these findings provide molecular insight into the mechanism of inhibitory synapse formation and maintenance in cerebellar cortex.
Collapse
|
2
|
Carricaburu E, Benner O, Burlingham SR, Dos Santos Passos C, Hobaugh N, Karr CH, Chanda S. Gephyrin promotes autonomous assembly and synaptic localization of GABAergic postsynaptic components without presynaptic GABA release. Proc Natl Acad Sci U S A 2024; 121:e2315100121. [PMID: 38889143 PMCID: PMC11214061 DOI: 10.1073/pnas.2315100121] [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: 08/30/2023] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Synapses containing γ-aminobutyric acid (GABA) constitute the primary centers for inhibitory neurotransmission in our nervous system. It is unclear how these synaptic structures form and align their postsynaptic machineries with presynaptic terminals. Here, we monitored the cellular distribution of several GABAergic postsynaptic proteins in a purely glutamatergic neuronal culture derived from human stem cells, which virtually lacks any vesicular GABA release. We found that several GABAA receptor (GABAAR) subunits, postsynaptic scaffolds, and major cell-adhesion molecules can reliably coaggregate and colocalize at even GABA-deficient subsynaptic domains, but remain physically segregated from glutamatergic counterparts. Genetic deletions of both Gephyrin and a Gephyrin-associated guanosine di- or triphosphate (GDP/GTP) exchange factor Collybistin severely disrupted the coassembly of these postsynaptic compositions and their proper apposition with presynaptic inputs. Gephyrin-GABAAR clusters, developed in the absence of GABA transmission, could be subsequently activated and even potentiated by delayed supply of vesicular GABA. Thus, molecular organization of GABAergic postsynapses can initiate via a GABA-independent but Gephyrin-dependent intrinsic mechanism.
Collapse
Affiliation(s)
- Etta Carricaburu
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Orion Benner
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Scott R. Burlingham
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | | | - Natalia Hobaugh
- Biological Sciences Division, University of Chicago, Chicago, IL60637
| | - Charles H. Karr
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Soham Chanda
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
- Molecular, Cellular and Integrated Neurosciences Program, Colorado State University, Fort Collins, CO80523
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO80523
| |
Collapse
|
3
|
Jahncke JN, Miller DS, Krush M, Schnell E, Wright KM. Inhibitory CCK+ basket synapse defects in mouse models of dystroglycanopathy. eLife 2024; 12:RP87965. [PMID: 38179984 PMCID: PMC10942650 DOI: 10.7554/elife.87965] [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] [Indexed: 01/06/2024] Open
Abstract
Dystroglycan (Dag1) is a transmembrane glycoprotein that links the extracellular matrix to the actin cytoskeleton. Mutations in Dag1 or the genes required for its glycosylation result in dystroglycanopathy, a type of congenital muscular dystrophy characterized by a wide range of phenotypes including muscle weakness, brain defects, and cognitive impairment. We investigated interneuron (IN) development, synaptic function, and associated seizure susceptibility in multiple mouse models that reflect the wide phenotypic range of dystroglycanopathy neuropathology. Mice that model severe dystroglycanopathy due to forebrain deletion of Dag1 or Pomt2, which is required for Dystroglycan glycosylation, show significant impairment of CCK+/CB1R+ IN development. CCK+/CB1R+ IN axons failed to properly target the somatodendritic compartment of pyramidal neurons in the hippocampus, resulting in synaptic defects and increased seizure susceptibility. Mice lacking the intracellular domain of Dystroglycan have milder defects in CCK+/CB1R+ IN axon targeting, but exhibit dramatic changes in inhibitory synaptic function, indicating a critical postsynaptic role of this domain. In contrast, CCK+/CB1R+ IN synaptic function and seizure susceptibility was normal in mice that model mild dystroglycanopathy due to partially reduced Dystroglycan glycosylation. Collectively, these data show that inhibitory synaptic defects and elevated seizure susceptibility are hallmarks of severe dystroglycanopathy, and show that Dystroglycan plays an important role in organizing functional inhibitory synapse assembly.
Collapse
Affiliation(s)
- Jennifer N Jahncke
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Milana Krush
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Eric Schnell
- Operative Care Division, Portland VA Health Care SystemPortlandUnited States
- Anesthesiology and Perioperative Medicine, Oregon Health & Science UniversityPortlandUnited States
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| |
Collapse
|
4
|
Boxer EE, Aoto J. Neurexins and their ligands at inhibitory synapses. Front Synaptic Neurosci 2022; 14:1087238. [PMID: 36618530 PMCID: PMC9812575 DOI: 10.3389/fnsyn.2022.1087238] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Since the discovery of neurexins (Nrxns) as essential and evolutionarily conserved synaptic adhesion molecules, focus has largely centered on their functional contributions to glutamatergic synapses. Recently, significant advances to our understanding of neurexin function at GABAergic synapses have revealed that neurexins can play pleiotropic roles in regulating inhibitory synapse maintenance and function in a brain-region and synapse-specific manner. GABAergic neurons are incredibly diverse, exhibiting distinct synaptic properties, sites of innervation, neuromodulation, and plasticity. Different classes of GABAergic neurons often express distinct repertoires of Nrxn isoforms that exhibit differential alternative exon usage. Further, Nrxn ligands can be differentially expressed and can display synapse-specific localization patterns, which may contribute to the formation of a complex trans-synaptic molecular code that establishes the properties of inhibitory synapse function and properties of local circuitry. In this review, we will discuss how Nrxns and their ligands sculpt synaptic inhibition in a brain-region, cell-type and synapse-specific manner.
Collapse
Affiliation(s)
| | - Jason Aoto
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Denver, CO, United States
| |
Collapse
|
5
|
Zarrouki F, Goutal S, Vacca O, Garcia L, Tournier N, Goyenvalle A, Vaillend C. Abnormal Expression of Synaptic and Extrasynaptic GABAA Receptor Subunits in the Dystrophin-Deficient mdx Mouse. Int J Mol Sci 2022; 23:ijms232012617. [PMID: 36293496 PMCID: PMC9604073 DOI: 10.3390/ijms232012617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/21/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a neurodevelopmental disorder primarily caused by the loss of the full-length Dp427 dystrophin in both muscle and brain. The basis of the central comorbidities in DMD is unclear. Brain dystrophin plays a role in the clustering of central gamma-aminobutyric acid A receptors (GABAARs), and its loss in the mdx mouse alters the clustering of some synaptic subunits in central inhibitory synapses. However, the diversity of GABAergic alterations in this model is still fragmentary. In this study, the analysis of in vivo PET imaging of a benzodiazepine-binding site radioligand revealed that the global density of central GABAARs is unaffected in mdx compared with WT mice. In contrast, semi-quantitative immunoblots and immunofluorescence confocal imaging in tissue sections revealed complex and differential patterns of alterations of the expression levels and/or clustered distribution of a variety of synaptic and extrasynaptic GABAAR subunits in the hippocampus, cerebellum, cortex, and spinal cord. Hence, dystrophin loss not only affects the stabilization of synaptic GABAARs but also influences the subunit composition of GABAARs subtypes at both synaptic and extrasynaptic sites. This study provides new molecular outcome measures and new routes to evaluate the impact of treatments aimed at compensating alterations of the nervous system in DMD.
Collapse
Affiliation(s)
- Faouzi Zarrouki
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, 91400 Saclay, France
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Sébastien Goutal
- Université Paris-Saclay, INSERM, CNRS, CEA, Laboratoire d’Imagerie Biomédicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 91401 Orsay, France
| | - Ophélie Vacca
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Luis Garcia
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Nicolas Tournier
- Université Paris-Saclay, INSERM, CNRS, CEA, Laboratoire d’Imagerie Biomédicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 91401 Orsay, France
| | - Aurélie Goyenvalle
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, 91400 Saclay, France
- Correspondence:
| |
Collapse
|
6
|
Jackson T, Seifi M, Górecki DC, Swinny JD. Specific Dystrophins Selectively Associate with Inhibitory and Excitatory Synapses of the Mouse Cerebellum and their Loss Alters Expression of P2X7 Purinoceptors and Pro-Inflammatory Mediators. Cell Mol Neurobiol 2022; 42:2357-2377. [PMID: 34101068 PMCID: PMC9418305 DOI: 10.1007/s10571-021-01110-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) patients, having mutations of the DMD gene, present with a range of neuropsychiatric disorders, in addition to the quintessential muscle pathology. The neurobiological basis remains poorly understood because the contributions of different DMD gene products (dystrophins) to the different neural networks underlying such symptoms are yet to be fully characterised. While full-length dystrophin clusters in inhibitory synapses, with inhibitory neurotransmitter receptors, the precise subcellular expression of truncated DMD gene products with excitatory synapses remains unresolved. Furthermore, inflammation, involving P2X purinoceptor 7 (P2RX7) accompanies DMD muscle pathology, yet any association with brain dystrophins is yet to be established. The aim of this study was to investigate the comparative expression of different dystrophins, alongside ionotropic glutamate receptors and P2RX7s, within the cerebellar circuitry known to express different dystrophin isoforms. Immunoreactivity for truncated DMD gene products was targeted to Purkinje cell (PC) distal dendrites adjacent to, or overlapping with, signal for GluA1, GluA4, GluN2A, and GluD2 receptor subunits. P2X7R immunoreactivity was located in Bergmann glia profiles adjacent to PC-dystrophin immunoreactivity. Ablation of all DMD gene products coincided with decreased mRNA expression for Gria2, Gria3, and Grin2a and increased GluD2 immunoreactivity. Finally, dystrophin-null mice showed decreased brain mRNA expression of P2rx7 and several inflammatory mediators. The data suggest that PCs target different dystrophin isoforms to molecularly and functionally distinct populations of synapses. In contrast to muscle, dystrophinopathy in brain leads to the dampening of the local immune system.
Collapse
Affiliation(s)
- Torquil Jackson
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK
| | - Mohsen Seifi
- Leicester School of Pharmacy, De Montfort University, Leicester, LE1 9BH, UK
| | - Dariusz C Górecki
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK
- Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-001, Warsaw, Poland
| | - Jerome D Swinny
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK.
| |
Collapse
|
7
|
Hawkes CA, Heath CJ, Sharp MM, Górecki DC, Carare RO. α-Dystrobrevin knockout mice have increased motivation for appetitive reward and altered brain cannabinoid receptor 1 expression. Acta Neuropathol Commun 2022; 10:127. [PMID: 36045406 PMCID: PMC9434862 DOI: 10.1186/s40478-022-01434-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/22/2022] [Indexed: 11/22/2022] Open
Abstract
α-Dystrobrevin (α-DB) is a major component of the dystrophin-associated protein complex (DAPC). Knockout (KO) of α-DB in the brain is associated with astrocytic abnormalities and loss of neuronal GABA receptor clustering. Mutations in DAPC proteins are associated with altered dopamine signaling and cognitive and psychiatric disorders, including schizophrenia. This study tested the hypothesis that motivation and associated underlying biological pathways are altered in the absence of α-DB expression. Male wildtype and α-DB KO mice were tested for measures of motivation, executive function and extinction in the rodent touchscreen apparatus. Subsequently, brain tissues were evaluated for mRNA and/or protein levels of dysbindin-1, dopamine transporter and receptor 1 and 2, mu opioid receptor 1 (mOR1) and cannabinoid receptor 1 (CB1). α-DB KO mice had significantly increased motivation for the appetitive reward, while measures of executive function and extinction were unaffected. No differences were observed between wildtype and KO animals on mRNA levels of dysbindin-1 or any of the dopamine markers. mRNA levels of mOR1were significantly decreased in the caudate-putamen and nucleus accumbens of α-DB KO compared to WT animals, but protein levels were unaltered. However, CB1 protein levels were significantly increased in the prefrontal cortex and decreased in the nucleus accumbens of α-DB KO mice. Triple-labelling immunohistochemistry confirmed that changes in CB1 were not specific to astrocytes. These results highlight a novel role for α-DB in the regulation of appetitive motivation that may have implications for other behaviours that involve the dopaminergic and endocannabinoid systems.
Collapse
|
8
|
Zarrouki F, Relizani K, Bizot F, Tensorer T, Garcia L, Vaillend C, Goyenvalle A. Partial restoration of brain dystrophin and behavioral deficits by exon skipping in the muscular dystrophy X-linked (mdx) mouse. Ann Neurol 2022; 92:213-229. [PMID: 35587226 PMCID: PMC9544349 DOI: 10.1002/ana.26409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 11/08/2022]
Abstract
Objectives Duchenne muscular dystrophy is associated with various degrees of cognitive impairment and behavioral disturbances. Emotional and memory deficits also constitute reliable outcome measures to assess efficacy of treatments in the mdx mouse lacking the muscle and neuronal full‐length dystrophins. The present study aimed to evaluate whether these deficits could be alleviated by the restoration of brain dystrophin. Methods We performed intracerebroventricular administration of a new potent tricyclo‐DNA antisense oligonucleotide (tcDNA‐ASO) containing a full phosphodiester backbone conjugated to a palmitic acid moiety (tcDNA‐ASO), designed to skip the mutated exon 23 of mdx mice. Results We first show that the tcDNA‐ASO rescues expression of brain dystrophin to 10–30% of wild‐type levels and significantly reduces the abnormal unconditioned fear responses in mdx mice in a dose‐dependent manner, 5 weeks post‐injection. Exon skipping efficiency, ASO biodistribution, protein restoration and effect on the fear response were optimal with a dose of 400 μg at 6–7 weeks post‐injection, with synaptic‐like expression in brain tissues such as the hippocampus and amygdala. Furthermore, this dose of tcDNA‐ASO restored long‐term memory retention of mdx mice in an object recognition task, but only had minor effects on fear conditioning. Interpretation These results suggest for the first time that postnatal re‐expression of brain dystrophin could reverse or at least alleviate some cognitive deficits associated with Duchenne muscular dystrophy. ANN NEUROL 2022;92:213–229
Collapse
Affiliation(s)
- Faouzi Zarrouki
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France.,Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, 91400, Saclay, France
| | - Karima Relizani
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France.,SQY Therapeutics, UVSQ, 78180, Montigny le Bretonneux, France
| | - Flavien Bizot
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France
| | - Thomas Tensorer
- SQY Therapeutics, UVSQ, 78180, Montigny le Bretonneux, France
| | - Luis Garcia
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France.,LIA BAHN, centre scientifique de Monaco, 98000, Monaco
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, 91400, Saclay, France
| | - Aurélie Goyenvalle
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France.,LIA BAHN, centre scientifique de Monaco, 98000, Monaco
| |
Collapse
|
9
|
Stefano MED, Ferretti V, Mozzetta C. Synaptic alterations as a neurodevelopmental trait of Duchenne muscular dystrophy. Neurobiol Dis 2022; 168:105718. [PMID: 35390481 DOI: 10.1016/j.nbd.2022.105718] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/14/2023] Open
Abstract
Dystrophinopaties, e.g., Duchenne muscular dystrophy (DMD), Becker muscular dystrophy and X-linked dilated cardiomyopathy are inherited neuromuscular diseases, characterized by progressive muscular degeneration, which however associate with a significant impact on general system physiology. The more severe is the pathology and its diversified manifestations, the heavier are its effects on organs, systems, and tissues other than muscles (skeletal, cardiac and smooth muscles). All dystrophinopaties are characterized by mutations in a single gene located on the X chromosome encoding dystrophin (Dp427) and its shorter isoforms, but DMD is the most devasting: muscular degenerations manifests within the first 4 years of life, progressively affecting motility and other muscular functions, and leads to a fatal outcome between the 20s and 40s. To date, after years of studies on both DMD patients and animal models of the disease, it has been clearly demonstrated that a significant percentage of DMD patients are also afflicted by cognitive, neurological, and autonomic disorders, of varying degree of severity. The anatomical correlates underlying neural functional damages are established during embryonic development and the early stages of postnatal life, when brain circuits, sensory and motor connections are still maturing. The impact of the absence of Dp427 on the development, differentiation, and consolidation of specific cerebral circuits (hippocampus, cerebellum, prefrontal cortex, amygdala) is significant, and amplified by the frequent lack of one or more of its lower molecular mass isoforms. The most relevant aspect, which characterizes DMD-associated neurological disorders, is based on morpho-functional alterations of selective synaptic connections within the affected brain areas. This pathological feature correlates neurological conditions of DMD to other severe neurological disorders, such as schizophrenia, epilepsy and autistic spectrum disorders, among others. This review discusses the organization and the role of the dystrophin-dystroglycan complex in muscles and neurons, focusing on the neurological aspect of DMD and on the most relevant morphological and functional synaptic alterations, in both central and autonomic nervous systems, described in the pathology and its animal models.
Collapse
Affiliation(s)
- Maria Egle De Stefano
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy; Center for Research in Neurobiology Daniel Bovet, Sapienza University of Rome, 00185 Rome, Italy.
| | - Valentina Ferretti
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy; Center for Research in Neurobiology Daniel Bovet, Sapienza University of Rome, 00185 Rome, Italy
| | - Chiara Mozzetta
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) of Italy c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
| |
Collapse
|
10
|
Deficiency of Glycosylated α-Dystroglycan in Ventral Hippocampus Bridges the Destabilization of Gamma-Aminobutyric Acid Type A Receptors With the Depressive-like Behaviors of Male Mice. Biol Psychiatry 2022; 91:593-603. [PMID: 35063187 DOI: 10.1016/j.biopsych.2021.10.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND Depression is a common psychiatric disorder associated with defects in GABAergic (gamma-aminobutyric acidergic) neurotransmission. α-Dystroglycan (α-DG), a cell adhesion molecule known to be essential for skeletal muscle integrity, is also present at inhibitory synapses in the central nervous system and forms a structural element in certain synapses. However, the role of α-DG in the regulation of depressive-like behaviors remains largely unknown. METHODS Depressive-like behaviors were induced by chronic social defeat stress in adult male mice. Surface protein was extracted by a biotin kit, and the expression of protein was detected by Western blotting. Intrahippocampal microinjection of the lentivirus or adeno-associated virus or agrin intervention was carried out using a stereotaxic instrument and followed by behavioral tests. Miniature inhibitory postsynaptic currents were recorded by whole-cell patch-clamp techniques. RESULTS The expression of α-DG and glycosylated α-DG in the ventral hippocampus was significantly lower in chronic social defeat stress-susceptible male mice than in control mice, accompanied by a decreased surface expression of GABAA receptor γ2 subunit and reduced GABAergic neurotransmission. RNA interference-mediated knockdown of Dag1 increased the susceptibility of mice to subthreshold stress. Both in vivo administration of agrin and overexpression of like-acetylglucosaminyltransferase ameliorated depressive-like behaviors and restored the decrease in surface expression of GABAA receptor γ2 subunit and the amplitude of miniature inhibitory postsynaptic currents in chronic social defeat stress-exposed mice. CONCLUSIONS Our findings demonstrate that glycosylated α-DG plays a role in the pathophysiological process of depressive-like behaviors by regulating the surface expression of GABAA receptor γ2 subunit and GABAergic neurotransmission in the ventral hippocampus.
Collapse
|
11
|
Kramer RH, Rajappa R. Interrogating the function of GABA A receptors in the brain with optogenetic pharmacology. Curr Opin Pharmacol 2022; 63:102198. [PMID: 35276498 DOI: 10.1016/j.coph.2022.102198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/26/2022]
Abstract
To better understand neural circuits and behavior, microbial opsins have been developed as optogenetic tools for stimulating or inhibiting action potentials with high temporal and spatial precision. However, if we seek a more reductionist understanding of how neuronal circuits operate, we also need high-resolution tools for perturbing the function of synapses. By combining photochemical tools and molecular biology, a wide variety of light-regulated neurotransmitter receptors have been developed, enabling photo-control of excitatory, inhibitory, and modulatory synaptic transmission. Here we focus on photo-control of GABAA receptors, ligand-gated Cl- channels that underlie almost all synaptic inhibition in the mammalian brain. By conjugating a photoswitchable tethered ligand onto a genetically-modified subunit of the GABAA receptor, light-sensitivity can be conferred onto specific isoforms of the receptor. Through gene editing, this attachment site can be knocked into the genome, enabling photocontrol of endogenous GABAA receptors. This strategy can be employed to explore the cell biology and neurophysiology of GABAA receptors. This includes investigating how specific isoforms contribute to synaptic and tonic inhibition and understanding the roles they play in brain development, long-term synaptic plasticity, and learning and memory.
Collapse
Affiliation(s)
- Richard H Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States.
| | - Rajit Rajappa
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States
| |
Collapse
|
12
|
Miller DS, Wright KM. Neuronal Dystroglycan regulates postnatal development of CCK/cannabinoid receptor-1 interneurons. Neural Dev 2021; 16:4. [PMID: 34362433 PMCID: PMC8349015 DOI: 10.1186/s13064-021-00153-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/20/2021] [Indexed: 12/02/2022] Open
Abstract
Background The development of functional neural circuits requires the precise formation of synaptic connections between diverse neuronal populations. The molecular pathways that allow GABAergic interneuron subtypes in the mammalian brain to initially recognize their postsynaptic partners remain largely unknown. The transmembrane glycoprotein Dystroglycan is localized to inhibitory synapses in pyramidal neurons, where it is required for the proper function of CCK+ interneurons. However, the precise temporal requirement for Dystroglycan during inhibitory synapse development has not been examined. Methods In this study, we use NEXCre or Camk2aCreERT2 to conditionally delete Dystroglycan from newly-born or adult pyramidal neurons, respectively. We then analyze forebrain development from postnatal day 3 through adulthood, with a particular focus on CCK+ interneurons. Results In the absence of postsynaptic Dystroglycan in developing pyramidal neurons, presynaptic CCK+ interneurons fail to elaborate their axons and largely disappear from the cortex, hippocampus, amygdala, and olfactory bulb during the first two postnatal weeks. Other interneuron subtypes are unaffected, indicating that CCK+ interneurons are unique in their requirement for postsynaptic Dystroglycan. Dystroglycan does not appear to be required in adult pyramidal neurons to maintain CCK+ interneurons. Bax deletion did not rescue CCK+ interneurons in Dystroglycan mutants during development, suggesting that they are not eliminated by canonical apoptosis. Rather, we observed increased innervation of the striatum, suggesting that the few remaining CCK+ interneurons re-directed their axons to neighboring areas where Dystroglycan expression remained intact. Conclusion Together these findings show that Dystroglycan functions as part of a synaptic partner recognition complex that is required early for CCK+ interneuron development in the forebrain. Supplementary Information The online version contains supplementary material available at 10.1186/s13064-021-00153-1.
Collapse
Affiliation(s)
- Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, VIB 3435A, 3181 SW Sam Jackson Park Road, L474, Portland, OR, 97239-3098, USA.
| |
Collapse
|
13
|
Pregabalin-induced neuroprotection and gait improvement in dystrophic MDX mice. Mol Cell Neurosci 2021; 114:103632. [PMID: 34058345 DOI: 10.1016/j.mcn.2021.103632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/16/2021] [Accepted: 05/25/2021] [Indexed: 11/21/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disease linked to the X chromosome induced by mutations in the dystrophin gene. Neuroprotective drugs, such as pregabalin (PGB), can improve motor function through the modulation of excitatory synapses, together with anti-apoptotic and anti-inflammatory effects. The present work studied the effects of PGB in the preservation of dystrophic peripheral nerves, allowing motor improvements in MDX mice. Five weeks old MDX and C57BL/10 mice were treated with PGB (30 mg/kg/day, i.p.) or vehicle, for 28 consecutive days. The mice were sacrificed on the 9th week, the sciatic nerves were dissected out and processed for immunohistochemistry and qRT-PCR, for evaluating the expression of proteins and gene transcripts related to neuronal activity and Schwann cell function. The lumbar spinal cords were also processed for qRT-PCR to evaluate the expression of neurotrophic factors and pro- and anti-inflammatory cytokines. Cranial tibial muscles were dissected out for endplate evaluation with α-bungarotoxin. The recovery of motor function was monitored throughout the treatment, using a spontaneous walking track test (Catwalk system) and a forced locomotion test (Rotarod). The results showed that treatment with PGB reduced the retrograde effects of muscle degeneration/regeneration on the nervous system from the 5th to the 9th week in MDX mice. Thus, PGB induced protein expression in neurons and Schwann cells, protecting myelinated fibers. In turn, better axonal morphology and close-to-normal motor endplates were observed. Indeed, such effects resulted in improved motor coordination of dystrophic animals. We believe that treatment with PGB improved the balance between excitatory and inhibitory inputs to spinal motoneurons, increasing motor control. In addition, PGB enhanced peripheral nerve homeostasis, by positively affecting Schwann cells. In general, the present results indicate that pregabalin is effective in protecting the PNS during the development of DMD, improving motor coordination, indicating possible translation to the clinic.
Collapse
|
14
|
Wagner S, Lee C, Rojas L, Specht CG, Rhee J, Brose N, Papadopoulos T. The α3 subunit of GABA A receptors promotes formation of inhibitory synapses in the absence of collybistin. J Biol Chem 2021; 296:100709. [PMID: 33901490 PMCID: PMC8141935 DOI: 10.1016/j.jbc.2021.100709] [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: 10/20/2020] [Revised: 04/14/2021] [Accepted: 04/22/2021] [Indexed: 01/03/2023] Open
Abstract
Signaling at nerve cell synapses is a key determinant of proper brain function, and synaptic defects—or synaptopathies—are at the basis of many neurological and psychiatric disorders. Collybistin (CB), a brain-specific guanine nucleotide exchange factor, is essential for the formation of γ-aminobutyric acidergic (GABAergic) postsynapses in defined regions of the mammalian forebrain, including the hippocampus and basolateral amygdala. This process depends on a direct interaction of CB with the scaffolding protein gephyrin, which leads to the redistribution of gephyrin into submembranous clusters at nascent inhibitory synapses. Strikingly, synaptic clustering of gephyrin and GABAA type A receptors (GABAARs) in several brain regions, including the cerebral cortex and certain thalamic areas, is unperturbed in CB-deficient mice, indicating that the formation of a substantial subset of inhibitory postsynapses must be controlled by gephyrin-interacting proteins other than CB. Previous studies indicated that the α3 subunit of GABAARs (GABAAR-α3) binds directly and with high affinity to gephyrin. Here, we provide evidence (i) that a homooligomeric GABAAR-α3A343W mutant induces the formation of submembranous gephyrin clusters independently of CB in COS-7 cells, (ii) that gephyrin clustering is unaltered in the neuronal subpopulations endogenously expressing the GABAAR-α3 in CB-deficient brains, and (iii) that exogenous expression of GABAAR-α3 partially rescues impaired gephyrin clustering in CB-deficient hippocampal neurons. Our results identify an important role of GABAAR-α3 in promoting gephyrin-mediated and CB-independent formation of inhibitory postsynapses.
Collapse
Affiliation(s)
- Sven Wagner
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - ChoongKu Lee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Lucia Rojas
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Christian G Specht
- Diseases and Hormones of the Nervous System (DHNS), Inserm U1195, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | | |
Collapse
|
15
|
Interleukin-6: A neuro-active cytokine contributing to cognitive impairment in Duchenne muscular dystrophy? Cytokine 2020; 133:155134. [DOI: 10.1016/j.cyto.2020.155134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/24/2022]
|
16
|
Briatore F, Pregno G, Di Angelantonio S, Frola E, De Stefano ME, Vaillend C, Sassoè-Pognetto M, Patrizi A. Dystroglycan Mediates Clustering of Essential GABAergic Components in Cerebellar Purkinje Cells. Front Mol Neurosci 2020; 13:164. [PMID: 32982691 PMCID: PMC7485281 DOI: 10.3389/fnmol.2020.00164] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/11/2020] [Indexed: 01/02/2023] Open
Abstract
Muscle dystrophin–glycoprotein complex (DGC) links the intracellular cytoskeleton to the extracellular matrix. In neurons, dystroglycan and dystrophin, two major components of the DGC, localize in a subset of GABAergic synapses, where their function is unclear. Here we used mouse models to analyze the specific role of the DGC in the organization and function of inhibitory synapses. Loss of full-length dystrophin in mdx mice resulted in a selective depletion of the transmembrane β-dystroglycan isoform from inhibitory post-synaptic sites in cerebellar Purkinje cells. Remarkably, there were no differences in the synaptic distribution of the extracellular α-dystroglycan subunit, of GABAA receptors and neuroligin 2. In contrast, conditional deletion of the dystroglycan gene from Purkinje cells caused a disruption of the DGC and severely impaired post-synaptic clustering of neuroligin 2, GABAA receptors and scaffolding proteins. Accordingly, whole-cell patch-clamp analysis revealed a significant reduction in the frequency and amplitude of spontaneous IPSCs recorded from Purkinje cells. In the long-term, deletion of dystroglycan resulted in a significant decrease of GABAergic innervation of Purkinje cells and caused an impairment of motor learning functions. These results show that dystroglycan is an essential synaptic organizer at GABAergic synapses in Purkinje cells.
Collapse
Affiliation(s)
- Federica Briatore
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Giulia Pregno
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,Center for Life Nanoscience, Istituto Italiano di Tecnologia, Rome, Italy
| | - Elena Frola
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Maria Egle De Stefano
- Department of Biology and Biotechnology "Charles Darwin", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Cyrille Vaillend
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Marco Sassoè-Pognetto
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Annarita Patrizi
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy.,Schaller Research Group Leader at the German Cancer Research Center, Heidelberg, Germany
| |
Collapse
|
17
|
Caudal D, François V, Lafoux A, Ledevin M, Anegon I, Le Guiner C, Larcher T, Huchet C. Characterization of brain dystrophins absence and impact in dystrophin-deficient Dmdmdx rat model. PLoS One 2020; 15:e0230083. [PMID: 32160266 PMCID: PMC7065776 DOI: 10.1371/journal.pone.0230083] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/20/2020] [Indexed: 12/27/2022] Open
Abstract
Duchenne Muscular Dystrophy (DMD) is a severe muscle-wasting disease caused by mutations in the DMD gene encoding dystrophin, expressed mainly in muscles but also in other tissues like retina and brain. Non-progressing cognitive dysfunction occurs in 20 to 50% of DMD patients. Furthermore, loss of expression of the Dp427 dystrophin isoform in the brain of mdx mice, the most used animal model of DMD, leads to behavioral deficits thought to be linked to insufficiencies in synaptogenesis and channel clustering at synapses. Mdx mice where the locomotor phenotype is mild also display a high and maladaptive response to stress. Recently, we generated Dmdmdx rats carrying an out-of frame mutation in exon 23 of the DMD gene and exhibiting a skeletal and cardiac muscle phenotype similar to DMD patients. In order to evaluate the impact of dystrophin loss on behavior, we explored locomotion parameters as well as anhedonia, anxiety and response to stress, in Dmdmdx rats aged from 1.5 to 7 months, in comparison to wild-type (WT) littermates. Pattern of dystrophin expression in the brain of WT and Dmdmdx rats was characterized by western-blot analyses and immunohistochemistry. We showed that dystrophin-deficient Dmdmdx rats displayed motor deficits in the beam test, without association with depressive or anxiety-like phenotype. However, Dmdmdx rats exhibited a strong response to restraint-induced stress, with a large increase in freezings frequency and duration, suggesting an alteration in a functional circuit including the amygdala. In brain, large dystrophin isoform Dp427 was not expressed in mutant animals. Dmdmdx rat is therefore a good animal model for preclinical evaluations of new treatments for DMD but care must be taken with their responses to mild stress.
Collapse
Affiliation(s)
- Dorian Caudal
- Therassay Platform, CAPACITES, Université de Nantes, Nantes, France
- * E-mail:
| | - Virginie François
- Nantes Gene Therapy Laboratory, Université de Nantes, INSERM UMR 1089, Nantes, France
| | - Aude Lafoux
- Therassay Platform, CAPACITES, Université de Nantes, Nantes, France
| | | | | | - Caroline Le Guiner
- Nantes Gene Therapy Laboratory, Université de Nantes, INSERM UMR 1089, Nantes, France
| | | | - Corinne Huchet
- Therassay Platform, CAPACITES, Université de Nantes, Nantes, France
- Nantes Gene Therapy Laboratory, Université de Nantes, INSERM UMR 1089, Nantes, France
| |
Collapse
|
18
|
Cognitive impairment appears progressive in the mdx mouse. Neuromuscul Disord 2020; 30:368-388. [PMID: 32360405 PMCID: PMC7306157 DOI: 10.1016/j.nmd.2020.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/22/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive muscle wasting disease caused by mutations in the DMD gene, which encodes the large cytoskeletal protein dystrophin. Approximately one-third of DMD patient's exhibit cognitive problems yet it is unknown if cognitive impairments worsen with age. The mdx mouse model is deficient in dystrophin demonstrates cognitive abnormalities, but no studies have investigated this longitudinally. We assessed the consequences of dystrophin deficiency on brain morphology and cognition in male mdx mice. We utilised non-invasive methods to monitor CNS pathology with an aim to identify changes longitudinally (between 4 and 18 months old) which could be used as outcome measures. MRI identified a total brain volume (TBV) increase in control mice with ageing (p < 0.05); but the mdx mice TBV increased significantly more (p < 0.01). Voxel-based morphometry (VBM) identified decreases in grey matter volume, particularly in the hippocampus of the mdx brain, most noticeable from 12 months onwards, as were enlarged lateral ventricles in mdx mice. The caudate putamen of older mdx mice showed increases in T2- relaxometry which may be considered as evidence of increased water content. Hippocampal spatial learning and memory was decreased in mdx mice, particularly long-term memory, which progressively worsened with age. The novel object recognition (NOR) task highlighted elevated anxiety-related behaviour in older mdx mice. Our studies suggest that dystrophin deficiency causes a progressive cognitive impairment in mice (compared to ageing control mice), becoming evident at late disease stages, and may explain why progressive CNS symptoms are not obvious in DMD patients.
Collapse
|
19
|
Darmahkasih AJ, Rybalsky I, Tian C, Shellenbarger KC, Horn PS, Lambert JT, Wong BL. Neurodevelopmental, behavioral, and emotional symptoms common in Duchenne muscular dystrophy. Muscle Nerve 2020; 61:466-474. [PMID: 31909820 DOI: 10.1002/mus.26803] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 11/11/2022]
Abstract
INTRODUCTION We studied neurodevelopmental and behavioral/emotional symptoms in patients with Duchenne muscular dystrophy (DMD). METHODS Retrospective case series of neurodevelopmental and behavioral/emotional symptoms obtained through review of systems of 700 DMD patients in relation to dystrophin gene mutations. RESULTS The most common symptoms encountered were emotional/behavioral dysregulation (38.7%), inattention/hyperactive features (31.4%), obsessive and compulsive features (25.0%), and language/speech delays (24.4%). Most patients (72.7%) had at least one symptom. Patients with mutations near the 3' end of the dystrophin gene were at higher risk for developing inattention/hyperactive features, language/speech delays, and global intellectual delays. Those with mutations between exon 31 and 79 had higher risk of clustering of symptoms when compared with those upstream of exon 30. DISCUSSION Neurodevelopmental, emotional, and behavioral symptoms are common comorbidities in DMD. There is higher prevalence of inattention/hyperactive features, language/speech delays, and global intellectual delays in genotypes affecting the 3' end of the dystrophin gene.
Collapse
Affiliation(s)
- Andrew J Darmahkasih
- Pediatric Residency Program, University of California, Irvine/Children's Hospital of Orange County, Orange, California
| | - Irina Rybalsky
- Neurology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Cuixia Tian
- Division of Neurology, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Karen C Shellenbarger
- Department of Pediatrics, University of Massachusetts Medical School, Worchester, Massachusetts
| | - Paul S Horn
- Division of Neurology, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Joshua T Lambert
- Neurology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Brenda L Wong
- Department of Pediatrics, University of Massachusetts Medical School, Worchester, Massachusetts
| |
Collapse
|
20
|
Uezu A, Hisey E, Kobayashi Y, Gao Y, Bradshaw TWA, Devlin P, Rodriguiz R, Tata PR, Soderling S. Essential role for InSyn1 in dystroglycan complex integrity and cognitive behaviors in mice. eLife 2019; 8:e50712. [PMID: 31829939 PMCID: PMC6944460 DOI: 10.7554/elife.50712] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Human mutations in the dystroglycan complex (DGC) result in not only muscular dystrophy but also cognitive impairments. However, the molecular architecture critical for the synaptic organization of the DGC in neurons remains elusive. Here, we report Inhibitory Synaptic protein 1 (InSyn1) is a critical component of the DGC whose loss alters the composition of the GABAergic synapses, excitatory/inhibitory balance in vitro and in vivo, and cognitive behavior. Association of InSyn1 with DGC subunits is required for InSyn1 synaptic localization. InSyn1 null neurons also show a significant reduction in DGC and GABA receptor distribution as well as abnormal neuronal network activity. Moreover, InSyn1 null mice exhibit elevated neuronal firing patterns in the hippocampus and deficits in fear conditioning memory. Our results support the dysregulation of the DGC at inhibitory synapses and altered neuronal network activity and specific cognitive tasks via loss of a novel component, InSyn1.
Collapse
Affiliation(s)
- Akiyoshi Uezu
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Erin Hisey
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | | | - Yudong Gao
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Tyler WA Bradshaw
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Patrick Devlin
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Ramona Rodriguiz
- Department of Psychiatry and Behavioral SciencesDuke University Medical SchoolDurhamUnited States
- Mouse Behavioral and Neuroendocrine Analysis Core FacilityDuke University Medical SchoolDurhamUnited States
| | | | - Scott Soderling
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
- Department of NeurobiologyDuke University Medical SchoolDurhamUnited States
| |
Collapse
|
21
|
Kranig SA, Tschada R, Braun M, Patry C, Pöschl J, Frommhold D, Hudalla H. Dystrophin deficiency promotes leukocyte recruitment in mdx mice. Pediatr Res 2019; 86:188-194. [PMID: 31091530 DOI: 10.1038/s41390-019-0427-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/11/2019] [Accepted: 05/03/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND A growing body of evidence defines inflammation as a hallmark feature of disease pathogenesis of Duchenne muscular dystrophy. To tailor potential immune modulatory interventions, a better understanding of immune dysregulation in Duchenne muscular dystrophy is needed. We now asked whether dystrophin deficiency affects the cascade of leukocyte recruitment. METHODS We performed intravital microscopy on the cremaster muscle of wild-type and dystrophin-deficient mdx mice. Recruitment was triggered by preparation alone (traumatic inflammation) or in combination with scrotal TNFα injections. Neutrophilic infiltration of the cremaster muscle was assessed on tissue sections. Integrin expression on circulating neutrophils and serum levels of pro-inflammatory cytokines were measured by flow cytometry. RESULTS Mdx mice show increased rolling and adhesion at baseline (traumatic inflammation) and a more profound response upon TNFα injection compared with wild-type animals. In both models, neutrophilic infiltration of the cremaster muscle is increased. Upregulation of the integrins LFA-1 and Mac-1 on circulating leukocytes and pro-inflammatory cytokines IL-6 and CCL2 in the serum points toward systemically altered immune regulation in mdx mice. CONCLUSION We are the first to show exaggerated activation of the leukocyte recruitment cascade in a dystrophin-deficient organism in vivo.
Collapse
Affiliation(s)
- Simon Alexander Kranig
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Raphaela Tschada
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Maylis Braun
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Christian Patry
- Department of General Pediatrics, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Johannes Pöschl
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - David Frommhold
- Klinik für Kinderheilkunde und Jugendmedizin, 87700, Memmingen, Germany
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany.
| |
Collapse
|
22
|
Contreras A, Hines DJ, Hines RM. Molecular Specialization of GABAergic Synapses on the Soma and Axon in Cortical and Hippocampal Circuit Function and Dysfunction. Front Mol Neurosci 2019; 12:154. [PMID: 31297048 PMCID: PMC6607995 DOI: 10.3389/fnmol.2019.00154] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/31/2019] [Indexed: 12/24/2022] Open
Abstract
The diversity of inhibitory interneurons allows for the coordination and modulation of excitatory principal cell firing. Interneurons that release GABA (γ-aminobutyric acid) onto the soma and axon exert powerful control by virtue of proximity to the site of action potential generation at the axon initial segment (AIS). Here, we review and examine the cellular and molecular regulation of soma and axon targeting GABAergic synapses in the cortex and hippocampus. We also describe their role in controlling network activity in normal and pathological states. Recent studies have demonstrated a specific role for postsynaptic dystroglycan in the formation and maintenance of cholecystokinin positive basket cell terminals contacting the soma, and postsynaptic collybistin in parvalbumin positive chandelier cell contacts onto the AIS. Unique presynaptic molecular contributors, LGI2 and FGF13, expressed in parvalbumin positive basket cells and chandelier cells, respectively, have also recently been identified. Mutations in the genes encoding proteins critical for somatic and AIS inhibitory synapses have been associated with human disorders of the nervous system. Dystroglycan dysfunction in some congenital muscular dystrophies is associated with developmental brain malformations, intellectual disability, and rare epilepsy. Collybistin dysfunction has been linked to hyperekplexia, epilepsy, intellectual disability, and developmental disorders. Both LGI2 and FGF13 mutations are implicated in syndromes with epilepsy as a component. Advancing our understanding of the powerful roles of somatic and axonic GABAergic contacts in controlling activity patterns in the cortex and hippocampus will provide insight into the pathogenesis of epilepsy and other nervous system disorders.
Collapse
Affiliation(s)
- April Contreras
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Dustin J Hines
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| |
Collapse
|
23
|
Lionarons JM, Hoogland G, Hendriksen RGF, Faber CG, Hellebrekers DMJ, Van Koeveringe GA, Schipper S, Vles JSH. Dystrophin is expressed in smooth muscle and afferent nerve fibers in the rat urinary bladder. Muscle Nerve 2019; 60:202-210. [PMID: 31095755 PMCID: PMC6771971 DOI: 10.1002/mus.26518] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 05/08/2019] [Accepted: 05/11/2019] [Indexed: 11/10/2022]
Abstract
INTRODUCTION With increasing life expectancy, comorbidities become overt in Duchenne muscular dystrophy (DMD). Although micturition problems are common, bladder function is poorly understood in DMD. We studied dystrophin expression and multiple isoform involvement in the bladder during maturation to gain insights into their roles in micturition. METHODS Dystrophin distribution was evaluated in rat bladders by immunohistochemical colocalization with smooth muscle, interstitial, urothelial, and neuronal markers. Protein levels of Dp140, Dp71, and smooth muscle were quantitated by Western blotting of neonatal to adult rat bladders. RESULTS Dystrophin colocalized with smooth muscle cells and afferent nerve fibers. Dp71 was expressed two- to threefold higher compared with Dp140, independently of age. Age-related muscle mass changes did not influence isoform expression levels. DISCUSSION Dystrophin is expressed in smooth muscle cells and afferent nerve fibers in the urinary bladder, which underscores that micturition problems in DMD may have not solely a myogenic but also a neurogenic origin. Muscle Nerve 60: 202-210, 2019.
Collapse
Affiliation(s)
- Judith M Lionarons
- Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands.,School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Govert Hoogland
- School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ruben G F Hendriksen
- Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands.,School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands.,School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Danique M J Hellebrekers
- Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands.,School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Gommert A Van Koeveringe
- School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Urology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sandra Schipper
- School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Urology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Johan S H Vles
- Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands.,School for Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
24
|
Nickolls AR, Bönnemann CG. The roles of dystroglycan in the nervous system: insights from animal models of muscular dystrophy. Dis Model Mech 2018; 11:11/12/dmm035931. [PMID: 30578246 PMCID: PMC6307911 DOI: 10.1242/dmm.035931] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Dystroglycan is a cell membrane protein that binds to the extracellular matrix in a variety of mammalian tissues. The α-subunit of dystroglycan (αDG) is heavily glycosylated, including a special O-mannosyl glycoepitope, relying upon this unique glycosylation to bind its matrix ligands. A distinct group of muscular dystrophies results from specific hypoglycosylation of αDG, and they are frequently associated with central nervous system involvement, ranging from profound brain malformation to intellectual disability without evident morphological defects. There is an expanding literature addressing the function of αDG in the nervous system, with recent reports demonstrating important roles in brain development and in the maintenance of neuronal synapses. Much of these data are derived from an increasingly rich array of experimental animal models. This Review aims to synthesize the information from such diverse models, formulating an up-to-date understanding about the various functions of αDG in neurons and glia of the central and peripheral nervous systems. Where possible, we integrate these data with our knowledge of the human disorders to promote translation from basic mechanistic findings to clinical therapies that take the neural phenotypes into account. Summary: Dystroglycan is a ubiquitous matrix receptor linked to brain and muscle disease. Unraveling the functions of this protein will inform basic and translational research on neural development and muscular dystrophies.
Collapse
Affiliation(s)
- Alec R Nickolls
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.,Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
25
|
GABA release selectively regulates synapse development at distinct inputs on direction-selective retinal ganglion cells. Proc Natl Acad Sci U S A 2018; 115:E12083-E12090. [PMID: 30509993 DOI: 10.1073/pnas.1803490115] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Synaptic inhibition controls a neuron's output via functionally distinct inputs at two subcellular compartments, the cell body and the dendrites. It is unclear whether the assembly of these distinct inhibitory inputs can be regulated independently by neurotransmission. In the mammalian retina, γ-aminobutyric acid (GABA) release from starburst amacrine cells (SACs) onto the dendrites of on-off direction-selective ganglion cells (ooDSGCs) is essential for directionally selective responses. We found that ooDSGCs also receive GABAergic input on their somata from other amacrine cells (ACs), including ACs containing the vasoactive intestinal peptide (VIP). When net GABAergic transmission is reduced, somatic, but not dendritic, GABAA receptor clusters on the ooDSGC increased in number and size. Correlative fluorescence imaging and serial electron microscopy revealed that these enlarged somatic receptor clusters are localized to synapses. By contrast, selectively blocking vesicular GABA release from either SACs or VIP ACs did not alter dendritic or somatic receptor distributions on the ooDSGCs, showing that neither SAC nor VIP AC GABA release alone is required for the development of inhibitory synapses in ooDSGCs. Furthermore, a reduction in net GABAergic transmission, but not a selective reduction from SACs, increased excitatory drive onto ooDSGCs. This increased excitation may drive a homeostatic increase in ooDSGC somatic GABAA receptors. Differential regulation of GABAA receptors on the ooDSGC's soma and dendrites could facilitate homeostatic control of the ooDSGC's output while enabling the assembly of the GABAergic connectivity underlying direction selectivity to be indifferent to altered transmission.
Collapse
|
26
|
Früh S, Tyagarajan SK, Campbell B, Bosshard G, Fritschy JM. The catalytic function of the gephyrin-binding protein IQSEC3 regulates neurotransmitter-specific matching of pre- and post-synaptic structures in primary hippocampal cultures. J Neurochem 2018; 147:477-494. [DOI: 10.1111/jnc.14572] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 08/05/2018] [Accepted: 08/08/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Simon Früh
- Institute of Pharmacology and Toxicology; University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and Federal Institute of Technology (ETH) Zurich; Zurich Switzerland
| | - Shiva K. Tyagarajan
- Institute of Pharmacology and Toxicology; University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and Federal Institute of Technology (ETH) Zurich; Zurich Switzerland
| | - Benjamin Campbell
- Institute of Pharmacology and Toxicology; University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and Federal Institute of Technology (ETH) Zurich; Zurich Switzerland
| | - Giovanna Bosshard
- Institute of Pharmacology and Toxicology; University of Zurich; Zurich Switzerland
| | - Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology; University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and Federal Institute of Technology (ETH) Zurich; Zurich Switzerland
| |
Collapse
|
27
|
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]
|
28
|
Hendriksen RGF, Vles JSH, Aalbers MW, Chin RFM, Hendriksen JGM. Brain-related comorbidities in boys and men with Duchenne Muscular Dystrophy: A descriptive study. Eur J Paediatr Neurol 2018; 22:488-497. [PMID: 29306518 DOI: 10.1016/j.ejpn.2017.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 10/20/2017] [Accepted: 12/09/2017] [Indexed: 11/15/2022]
Abstract
AIM Duchenne Muscular Dystrophy (DMD) is more than a muscle disease since there is a higher prevalence of neuropsychological comorbidities. Similarly, the prevalence of epilepsy is increased. Given the nowadays-increasing interest in brain-related comorbidities in DMD, this study aimed to evaluate the relationship between DMD, epilepsy, and associated neurodevelopmental disorders in an international sample of DMD patients. METHOD Using a questionnaire-based study we investigated the occurrence of self/by-proxy reported brain-related comorbidities in a group of 228 DMD patients. We evaluated the presence of epilepsy and other brain-related comorbidities, but also the specific mutation in the dystrophin gene. With respect to epilepsy, all individually reported epilepsy cases as based on the questionnaire results including information provided on epilepsy treatment, EEG abnormalities, and a description of how a typical seizure would look like, were independently and blindly re-assessed by two external paediatric neurologists (Cohen's kappa of 0.85). RESULTS Based on the latter, 18 (7.9%) DMD patients were considered to have epilepsy. In patients with both DMD and epilepsy, certain other brain-related comorbidities (i.e. attention deficit hyperactivity disorder, obsessive compulsive disorder, anxiety disorders and sleep disorders) were significantly more prevalent. CONCLUSION This study is supportive of a high occurrence of epilepsy and other brain-related comorbidities in DMD. Furthermore this study shows for the first time that the frequency of some of these disorders appear to be further increased when epilepsy is present next to DMD. As this study is limited by the self/by proxy setup and the lack of response rates, future studies should elucidate the true incidence of the (triangular) cooccurrence between epilepsy, neurodevelopmental deficits, and DMD.
Collapse
Affiliation(s)
- Ruben G F Hendriksen
- Department of Neurology, Maastricht University Medical Centre, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health & Neuroscience (MHeNS), Maastricht University, Universiteitssingel 40, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
| | - Johan S H Vles
- Department of Neurology, Maastricht University Medical Centre, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
| | - Marlien W Aalbers
- Department of Neurosurgery, Groningen University Medical Centre, Hanzeplein 1, P.O. Box 30001, 9713 GZ Groningen, The Netherlands.
| | - Richard F M Chin
- Muir Maxwell Epilepsy Centre, The University of Edinburgh, Sylvan Road 20, EH9 1UW Edinburgh, United Kingdom; Department of Paediatric Neuroscience, Royal Hospital for Sick Children, Sciennes Road 9, EH9 1LF Edinburgh, United Kingdom.
| | - Jos G M Hendriksen
- Department of Neurology, Maastricht University Medical Centre, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands; Kempenhaeghe Epilepsy Centre, Centre for Neurological Learning Disabilities, Sterkselseweg 65, 5591 VE Heeze, The Netherlands.
| |
Collapse
|
29
|
Effects of (−)-epicatechin on frontal cortex DAPC and dysbindin of the mdx mice. Neurosci Lett 2017; 658:142-149. [DOI: 10.1016/j.neulet.2017.08.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/28/2017] [Accepted: 08/23/2017] [Indexed: 11/23/2022]
|
30
|
Differential role of GABA A receptors and neuroligin 2 for perisomatic GABAergic synapse formation in the hippocampus. Brain Struct Funct 2017. [PMID: 28643105 DOI: 10.1007/s00429-017-1462-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Perisomatic GABAergic synapses onto hippocampal pyramidal cells arise from two populations of basket cells with different neurochemical and functional properties. The presence of the dystrophin-glycoprotein complex in their postsynaptic density (PSD) distinguishes perisomatic synapses from GABAergic synapses on dendrites and the axon-initial segment. Targeted deletion of neuroligin 2 (NL2), a transmembrane protein interacting with presynaptic neurexin, has been reported to disrupt postsynaptic clustering of GABAA receptors (GABAAR) and their anchoring protein, gephyrin, at perisomatic synapses. In contrast, targeted deletion of Gabra2 disrupts perisomatic clustering of gephyrin, but not of α1-GABAAR, NL2, or dystrophin/dystroglycan. Unexpectedly, conditional deletion of Dag1, encoding dystroglycan, selectively prevents the formation of perisomatic GABAergic synapses from basket cells expressing cholecystokinin. Collectively, these observations suggest that multiple mechanisms regulate formation and molecular composition of the GABAergic PSD at perisomatic synapses. Here, we further explored this issue by investigating the effect of targeted deletion of Gabra1 and NL2 on the dystrophin-glycoprotein complex and on perisomatic synapse formation, using immunofluorescence analysis with a battery of GABAergic pre- and postsynaptic markers. We show that the absence of α1-GABAAR increases GABAergic synapses containing the α2 subunit, without affecting the clustering of dystrophin and NL2; in contrast, the absence of NL2 produces highly variable effects postsynaptically, not restricted to perisomatic synapses and being more severe for the GABAAR subunits and gephyrin than dystrophin. Altogether, the results confirm the importance of NL2 as organizer of the GABAergic PSD and unravel distinct roles for α1- and α2-GABAARs in the formation of GABAergic circuits in close interaction with the dystrophin-glycoprotein complex.
Collapse
|
31
|
Suzuki Y, Higuchi S, Aida I, Nakajima T, Nakada T. Abnormal distribution of GABA A receptors in brain of duchenne muscular dystrophy patients. Muscle Nerve 2017; 55:591-595. [PMID: 27543743 DOI: 10.1002/mus.25383] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2016] [Indexed: 11/06/2022]
Abstract
INTRODUCTION In this study we sought to: (1) determine the distribution of GABAA receptors (GABAA -Rs) in the brain of Duchenne muscular dystrophy (DMD) patients; and (2) ascertain if the distribution pattern correlates with cognitive dysfunction. METHODS Fourteen DMD patients [young adult (n = 7, 18-25 years old) and older adult (n = 7, 30-37 years old) groups] and 16 age-matched normal volunteers participated. GABAA -R distribution was assessed using 123 I-IMZ-SPECT. Neuropsychological assessments were performed using 3 different test batteries, the WAIS-III, WMS-R, and Wisconsin Card Sorting Test (WCST). RESULTS All DMD patients showed significant decline in 123 I-IMZ uptake in the prefrontal cortex (P < 0.05). Although no differences were detected in the WAIS-III and WMS-R, the WCST scores of DMD patients (2.8 ± 1.9) were significantly lower (P < 0.01) than those of normal volunteers (5.4 ± 0.7). Both abnormalities were more pronounced in older adult patients. CONCLUSION The findings demonstrate that DMD is accompanied by a reduction in the prefrontal cortex distribution of GABAA -Rs. Muscle Nerve 55: 591-595, 2017.
Collapse
Affiliation(s)
- Yuji Suzuki
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, 1-757 Asahimachi, Niigata, 951-8585, Japan.,National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Shinya Higuchi
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Izumi Aida
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Takashi Nakajima
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Tsutomu Nakada
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, 1-757 Asahimachi, Niigata, 951-8585, Japan
| |
Collapse
|
32
|
Hendriksen RGF, Schipper S, Hoogland G, Schijns OEMG, Dings JTA, Aalbers MW, Vles JSH. Dystrophin Distribution and Expression in Human and Experimental Temporal Lobe Epilepsy. Front Cell Neurosci 2016; 10:174. [PMID: 27458343 PMCID: PMC4937016 DOI: 10.3389/fncel.2016.00174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/21/2016] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE Dystrophin is part of a protein complex that connects the cytoskeleton to the extracellular matrix. In addition to its role in muscle tissue, it functions as an anchoring protein within the central nervous system such as in hippocampus and cerebellum. Its presence in the latter regions is illustrated by the cognitive problems seen in Duchenne Muscular Dystrophy (DMD). Since epilepsy is also supposed to constitute a comorbidity of DMD, it is hypothesized that dystrophin plays a role in neuronal excitability. Here, we aimed to study brain dystrophin distribution and expression in both, human and experimental temporal lobe epilepsy (TLE). METHOD Regional and cellular dystrophin distribution was evaluated in both human and rat hippocampi and in rat cerebellar tissue by immunofluorescent colocalization with neuronal (NeuN and calbindin) and glial (GFAP) markers. In addition, hippocampal dystrophin levels were estimated by Western blot analysis in biopsies from TLE patients, post-mortem controls, amygdala kindled (AK)-, and control rats. RESULTS Dystrophin was expressed in all hippocampal pyramidal subfields and in the molecular-, Purkinje-, and granular cell layer of the cerebellum. In these regions it colocalized with GFAP, suggesting expression in astrocytes such as Bergmann glia (BG) and velate protoplasmic astrocytes. In rat hippocampus and cerebellum there were neither differences in dystrophin positive cell types, nor in the regional dystrophin distribution between AK and control animals. Quantitatively, hippocampal full-length dystrophin (Dp427) levels were about 60% higher in human TLE patients than in post-mortem controls (p < 0.05), whereas the level of the shorter Dp71 isoform did not differ. In contrast, AK animals showed similar dystrophin levels as controls. CONCLUSION Dystrophin is ubiquitously expressed by astrocytes in the human and rat hippocampus and in the rat cerebellum. Hippocampal full-length dystrophin (Dp427) levels are upregulated in human TLE, but not in AK rats, possibly indicating a compensatory mechanism in the chronic epileptic human brain.
Collapse
Affiliation(s)
- Ruben G F Hendriksen
- Department of Neurology, Maastricht University Medical Centre Maastricht, Netherlands
| | - Sandra Schipper
- Department of Neurology, Maastricht University Medical CentreMaastricht, Netherlands; School for Mental Health and Neuroscience, Maastricht UniversityMaastricht, Netherlands
| | - Govert Hoogland
- School for Mental Health and Neuroscience, Maastricht UniversityMaastricht, Netherlands; Department of Neurosurgery, Maastricht University Medical CentreMaastricht, Netherlands
| | - Olaf E M G Schijns
- Department of Neurosurgery, Maastricht University Medical Centre Maastricht, Netherlands
| | - Jim T A Dings
- Department of Neurosurgery, Maastricht University Medical Centre Maastricht, Netherlands
| | - Marlien W Aalbers
- Department of Neurosurgery, Groningen University Medical Centre Groningen, Netherlands
| | - Johan S H Vles
- Department of Neurology, Maastricht University Medical Centre Maastricht, Netherlands
| |
Collapse
|
33
|
Rae MG, O'Malley D. Cognitive dysfunction in Duchenne muscular dystrophy: a possible role for neuromodulatory immune molecules. J Neurophysiol 2016; 116:1304-15. [PMID: 27385793 DOI: 10.1152/jn.00248.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/29/2016] [Indexed: 11/22/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X chromosome-linked disease characterized by progressive physical disability, immobility, and premature death in affected boys. Underlying the devastating symptoms of DMD is the loss of dystrophin, a structural protein that connects the extracellular matrix to the cell cytoskeleton and provides protection against contraction-induced damage in muscle cells, leading to chronic peripheral inflammation. However, dystrophin is also expressed in neurons within specific brain regions, including the hippocampus, a structure associated with learning and memory formation. Linked to this, a subset of boys with DMD exhibit nonprogressing cognitive dysfunction, with deficits in verbal, short-term, and working memory. Furthermore, in the genetically comparable dystrophin-deficient mdx mouse model of DMD, some, but not all, types of learning and memory are deficient, and specific deficits in synaptogenesis and channel clustering at synapses has been noted. Little consideration has been devoted to the cognitive deficits associated with DMD compared with the research conducted into the peripheral effects of dystrophin deficiency. Therefore, this review focuses on what is known about the role of full-length dystrophin (Dp427) in hippocampal neurons. The importance of dystrophin in learning and memory is assessed, and the potential importance that inflammatory mediators, which are chronically elevated in dystrophinopathies, may have on hippocampal function is also evaluated.
Collapse
Affiliation(s)
- Mark G Rae
- Department of Physiology, University College Cork, Cork, Ireland; and
| | - Dervla O'Malley
- Department of Physiology, University College Cork, Cork, Ireland; and APC Microbiome Institute, University College Cork, Cork, Ireland
| |
Collapse
|
34
|
Deprez F, Pallotto M, Vogt F, Grabiec M, Virtanen MA, Tyagarajan SK, Panzanelli P, Fritschy JM. Postsynaptic gephyrin clustering controls the development of adult-born granule cells in the olfactory bulb. J Comp Neurol 2016; 523:1998-2016. [PMID: 25772192 DOI: 10.1002/cne.23776] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 01/01/2023]
Abstract
In adult rodent olfactory bulb, GABAergic signaling regulates migration, differentiation, and synaptic integration of newborn granule cells (GCs), migrating from the subventricular zone. Here we show that these effects depend on the formation of a postsynaptic scaffold organized by gephyrin-the main scaffolding protein of GABAergic synapses, which anchors receptors and signaling molecules to the postsynaptic density-and are regulated by the phosphorylation status of gephyrin. Using lentiviral vectors to selectively transfect adult-born GCs, we observed that overexpression of the phospho-deficient gephyrin mutant eGFP-gephyrin(S270A), which facilitates the formation of supernumerary GABAergic synapses in vitro, favors dendritic branching and the formation of transient GABAergic synapses on spines, identified by the presence of α2-GABAA Rs. In contrast, overexpression of the dominant-negative eGFP-gephyrin(L2B) (a chimera that is enzymatically active but clustering defective), curtailed dendritic growth, spine formation, and long-term survival of GCs, pointing to the essential role of gephyrin cluster formation for its function. We could exclude any gephyrin overexpression artifacts, as GCs infected with eGFP-gephyrin were comparable to those infected with eGFP alone. The opposite effects induced by the two gephyrin mutant constructs indicate that the gephyrin scaffold at GABAergic synapses orchestrates signaling cascades acting on the cytoskeleton to regulate neuronal growth and synapse formation. Specifically, gephyrin phosphorylation emerges as a novel mechanism regulating morphological differentiation and long-term survival of adult-born olfactory bulb neurons.
Collapse
Affiliation(s)
- Francine Deprez
- University of Zurich, Institute of Pharmacology and Toxicology, 8057, Zurich, Switzerland.,Neuroscience Center Zurich, ETH and University of Zurich, Switzerland
| | - Marta Pallotto
- Circuit Dynamics and Connectivity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Fabia Vogt
- University of Zurich, Institute of Pharmacology and Toxicology, 8057, Zurich, Switzerland
| | - Marta Grabiec
- University of Zurich, Institute of Pharmacology and Toxicology, 8057, Zurich, Switzerland
| | - Mari A Virtanen
- Department of Neurosciences Fondamentales CMU, University of Geneva, 1211, Geneva, Switzerland
| | - Shiva K Tyagarajan
- University of Zurich, Institute of Pharmacology and Toxicology, 8057, Zurich, Switzerland.,Neuroscience Center Zurich, ETH and University of Zurich, Switzerland
| | - Patrizia Panzanelli
- University of Turin, Department of Neuroscience Rita Levi Montalcini, Turin, Italy
| | - Jean-Marc Fritschy
- University of Zurich, Institute of Pharmacology and Toxicology, 8057, Zurich, Switzerland.,Neuroscience Center Zurich, ETH and University of Zurich, Switzerland
| |
Collapse
|
35
|
Kim EJ, Jeon CS, Lee SY, Hwang I, Chung TD. Robust Type-specific Hemisynapses Induced by Artificial Dendrites. Sci Rep 2016; 6:24210. [PMID: 27072994 PMCID: PMC4829863 DOI: 10.1038/srep24210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/22/2016] [Indexed: 11/09/2022] Open
Abstract
Type-specificity of synapses, excitatory and inhibitory, regulates information process in neural networks via chemical neurotransmitters. To lay a foundation of synapse-based neural interfaces, artificial dendrites are generated by covering abiotic substrata with ectodomains of type-specific synaptogenic proteins that are C-terminally tagged with biotinylated fluorescent proteins. The excitatory artificial synapses displaying engineered ectodomains of postsynaptic neuroligin-1 (NL1) induce the formation of excitatory presynapses with mixed culture of neurons in various developmental stages, while the inhibitory artificial dendrites displaying engineered NL2 and Slitrk3 induce inhibitory presynapses only with mature neurons. By contrast, if the artificial dendrites are applied to the axonal components of micropatterned neurons, correctly-matched synaptic specificity emerges regardless of the neuronal developmental stages. The hemisynapses retain their initially established type-specificity during neuronal development and maintain their synaptic strength provided live neurons, implying the possibility of durable synapse-based biointerfaces.
Collapse
Affiliation(s)
- Eun Joong Kim
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| | - Chang Su Jeon
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| | - Soo Youn Lee
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| | - Inseong Hwang
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| | - Taek Dong Chung
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| |
Collapse
|
36
|
Mircsof D, Langouët M, Rio M, Moutton S, Siquier-Pernet K, Bole-Feysot C, Cagnard N, Nitschke P, Gaspar L, Žnidarič M, Alibeu O, Fritz AK, Wolfer DP, Schröter A, Bosshard G, Rudin M, Koester C, Crestani F, Seebeck P, Boddaert N, Prescott K, Hines R, Moss SJ, Fritschy JM, Munnich A, Amiel J, Brown SA, Tyagarajan SK, Colleaux L. Mutations in NONO lead to syndromic intellectual disability and inhibitory synaptic defects. Nat Neurosci 2015; 18:1731-6. [PMID: 26571461 PMCID: PMC5392243 DOI: 10.1038/nn.4169] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/15/2015] [Indexed: 12/14/2022]
Abstract
The NONO protein has been characterized as an important transcriptional regulator in diverse cellular contexts. Here we show that loss of NONO function is a likely cause of human intellectual disability and that NONO-deficient mice have cognitive and affective deficits. Correspondingly, we find specific defects at inhibitory synapses, where NONO regulates synaptic transcription and gephyrin scaffold structure. Our data identify NONO as a possible neurodevelopmental disease gene and highlight the key role of the DBHS protein family in functional organization of GABAergic synapses.
Collapse
Affiliation(s)
- Dennis Mircsof
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland.,Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Maéva Langouët
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Marlène Rio
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France.,Service de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Sébastien Moutton
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Karine Siquier-Pernet
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Christine Bole-Feysot
- Genomic Platform, INSERM UMR 1163, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Nicolas Cagnard
- Bioinformatic Platform, INSERM UMR 1163, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Patrick Nitschke
- Bioinformatic Platform, INSERM UMR 1163, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Ludmila Gaspar
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Matej Žnidarič
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Olivier Alibeu
- Genomic Platform, INSERM UMR 1163, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Ann-Kristina Fritz
- Institute of Anatomy, University of Zürich and Institute of Human Movement Sciences and Sport, ETH Zürich, Switzerland
| | - David P Wolfer
- Institute of Anatomy, University of Zürich and Institute of Human Movement Sciences and Sport, ETH Zürich, Switzerland
| | - Aileen Schröter
- Molecular Imaging and Functional Pharmacology Group, University of Zürich, Zürich, Switzerland
| | - Giovanna Bosshard
- Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Markus Rudin
- Molecular Imaging and Functional Pharmacology Group, University of Zürich, Zürich, Switzerland
| | - Christina Koester
- Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Florence Crestani
- Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Petra Seebeck
- Center for Integrative Rodent Physiology, University of Zürich, Zürich, Switzerland
| | - Nathalie Boddaert
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France.,Service de radiologie pédiatrique, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Katrina Prescott
- Yorkshire Regional Genetics Service, Leeds Teaching Hospitals National Health Service Trust, Department of Clinical Genetics, Chapel Allerton Hospital, Chapeltown Road, Leeds, UK
| | | | - Rochelle Hines
- Tufts University, Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts, USA
| | - Steven J Moss
- Tufts University, Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts, USA
| | - Jean-Marc Fritschy
- Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Arnold Munnich
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| | - Jeanne Amiel
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France.,Service de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Steven A Brown
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Shiva K Tyagarajan
- Neuromorphology Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Laurence Colleaux
- INSERM UMR 1163, Laboratory of Molecular and Pathophysiological Bases of Cognitive Disorders, Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Necker-Enfants Malades Hospital, Paris, France
| |
Collapse
|
37
|
Hendriksen RG, Hoogland G, Schipper S, Hendriksen JG, Vles JS, Aalbers MW. A possible role of dystrophin in neuronal excitability: A review of the current literature. Neurosci Biobehav Rev 2015; 51:255-62. [DOI: 10.1016/j.neubiorev.2015.01.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 01/18/2015] [Accepted: 01/31/2015] [Indexed: 10/24/2022]
|
38
|
Whitmore C, Morgan J. What do mouse models of muscular dystrophy tell us about the DAPC and its components? Int J Exp Pathol 2014; 95:365-77. [PMID: 25270874 PMCID: PMC4285463 DOI: 10.1111/iep.12095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/16/2014] [Indexed: 12/17/2022] Open
Abstract
There are over 30 mouse models with mutations or inactivations in the dystrophin-associated protein complex. This complex is thought to play a crucial role in the functioning of muscle, as both a shock absorber and signalling centre, although its role in the pathogenesis of muscular dystrophy is not fully understood. The first mouse model of muscular dystrophy to be identified with a mutation in a component of the dystrophin-associated complex (dystrophin) was the mdx mouse in 1984. Here, we evaluate the key characteristics of the mdx in comparison with other mouse mutants with inactivations in DAPC components, along with key modifiers of the disease phenotype. By discussing the differences between the individual phenotypes, we show that the functioning of the DAPC and consequently its role in the pathogenesis is more complicated than perhaps currently appreciated.
Collapse
Affiliation(s)
- Charlotte Whitmore
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
| | - Jennifer Morgan
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
| |
Collapse
|
39
|
Acetylcholine, GABA and neuronal networks: a working hypothesis for compensations in the dystrophic brain. Brain Res Bull 2014; 110:1-13. [PMID: 25445612 DOI: 10.1016/j.brainresbull.2014.10.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 11/22/2022]
Abstract
Duchenne muscular dystrophy (DMD), a genetic disease arising from a mutation in the dystrophin gene, is characterized by muscle failure and is often associated with cognitive deficits. Studies of the dystrophic brain on the murine mdx model of DMD provide evidence of morphological and functional alterations in the central nervous system (CNS) possibly compatible with the cognitive impairment seen in DMD. However, while some of the alterations reported are a direct consequence of the absence of dystrophin, others seem to be associated only indirectly. In this review we reevaluate the literature in order to formulate a possible explanation for the cognitive impairments associated with DMD. We present a working hypothesis, demonstrated as an integrated neuronal network model, according to which within the cascade of events leading to cognitive impairments there are compensatory mechanisms aimed to maintain functional stability via perpetual adjustments of excitatory and inhibitory components. Such ongoing compensatory response creates continuous perturbations that disrupt neuronal functionality in terms of network efficiency. We have theorized that in this process acetylcholine and network oscillations play a central role. A better understating of these mechanisms could provide a useful diagnostic index of the disease's progression and, perhaps, the correct counterbalance of this process might help to prevent deterioration of the CNS in DMD. Furthermore, the involvement of compensatory mechanisms in the CNS could be extended beyond DMD and possibly help to clarify other physio-pathological processes of the CNS.
Collapse
|
40
|
Nikitczuk JS, Patil SB, Matikainen-Ankney BA, Scarpa J, Shapiro ML, Benson DL, Huntley GW. N-cadherin regulates molecular organization of excitatory and inhibitory synaptic circuits in adult hippocampus in vivo. Hippocampus 2014; 24:943-962. [PMID: 24753442 DOI: 10.1002/hipo.22282] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/09/2014] [Indexed: 12/31/2022]
Abstract
N-Cadherin and β-catenin form a transsynaptic adhesion complex required for spine and synapse development. In adulthood, N-cadherin mediates persistent synaptic plasticity, but whether the role of N-cadherin at mature synapses is similar to that at developing synapses is unclear. To address this, we conditionally ablated N-cadherin from excitatory forebrain synapses in mice starting in late postnatal life and examined hippocampal structure and function in adulthood. In the absence of N-cadherin, β-catenin levels were reduced, but numbers of excitatory synapses were unchanged, and there was no impact on number or shape of dendrites or spines. However, the composition of synaptic molecules was altered. Levels of GluA1 and its scaffolding protein PSD95 were diminished and the density of immunolabeled puncta was decreased, without effects on other glutamate receptors and their scaffolding proteins. Additionally, loss of N-cadherin at excitatory synapses triggered increases in the density of markers for inhibitory synapses and decreased severity of hippocampal seizures. Finally, adult mutant mice were profoundly impaired in hippocampal-dependent memory for spatial episodes. These results demonstrate a novel function for the N-cadherin/β-catenin complex in regulating ionotropic receptor composition of excitatory synapses, an appropriate balance of excitatory and inhibitory synaptic proteins and the maintenance of neural circuitry necessary to generate flexible yet persistent cognitive and synaptic function.
Collapse
Affiliation(s)
- Jessica S Nikitczuk
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Shekhar B Patil
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Bridget A Matikainen-Ankney
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Joseph Scarpa
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Matthew L Shapiro
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Deanna L Benson
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - George W Huntley
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| |
Collapse
|
41
|
Ledoux MS, Dauer WT, Warner TT. Emerging common molecular pathways for primary dystonia. Mov Disord 2014; 28:968-81. [PMID: 23893453 DOI: 10.1002/mds.25547] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 12/23/2022] Open
Abstract
The dystonias are a group of hyperkinetic movement disorders whose principal cause is neuron dysfunction at 1 or more interconnected nodes of the motor system. The study of genes and proteins that cause familial dystonia provides critical information about the cellular pathways involved in this dysfunction, which disrupts the motor pathways at the systems level. In recent years study of the increasing number of DYT genes has implicated a number of cell functions that appear to be involved in the pathogenesis of dystonia. A review of the literature published in English-language publications available on PubMed relating to the genetics and cellular pathology of dystonia was performed. Numerous potential pathogenetic mechanisms have been identified. We describe those that fall into 3 emerging thematic groups: cell-cycle and transcriptional regulation in the nucleus, endoplasmic reticulum and nuclear envelope function, and control of synaptic function. © 2013 Movement Disorder Society.
Collapse
Affiliation(s)
- Mark S Ledoux
- Department of Neurology, University of Tennessee Health Science Center Memphis, Tennessee 38163, USA
| | | | | |
Collapse
|
42
|
Schosser A, Butler AW, Uher R, Ng MY, Cohen-Woods S, Craddock N, Owen MJ, Korszun A, Gill M, Rice J, Hauser J, Henigsberg N, Maier W, Mors O, Placentino A, Rietschel M, Souery D, Preisig M, Craig IW, Farmer AE, Lewis CM, McGuffin P. Genome-wide association study of co-occurring anxiety in major depression. World J Biol Psychiatry 2013; 14:611-21. [PMID: 24047446 DOI: 10.3109/15622975.2013.782107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVES Co-morbidity between depression and anxiety disorders is common. In this study we define a quantitative measure of anxiety by summating four anxiety items from the SCAN interview in a large collection of major depression (MDD) cases to identify genes contributing to this complex phenotype. METHODS A total of 1522 MDD cases dichotomised according to those with at least one anxiety item scored (n = 1080) and those without anxiety (n = 442) were analysed, and also compared to 1588 healthy controls at a genome-wide level, to identify genes that may contribute to anxiety in MDD. RESULTS For the quantitative trait, suggestive evidence of association was detected for two SNPs, and for the dichotomous anxiety present/absent ratings for three SNPs at genome-wide level. In the genome-wide analysis of MDD cases with co-morbid anxiety and healthy controls, two SNPs attained P values of < 5 × 10⁻⁶. Analysing candidate genes, P values ≤ 0.0005 were found with three SNPs for the quantitative trait and three SNPs for the dichotomous trait. CONCLUSIONS This study provides an initial genome-wide assessment of possible genetic contribution to anxiety in MDD. Although suggestive evidence of association was found for several SNPs, our findings suggest that there are no common variants strongly associated with anxious depression.
Collapse
Affiliation(s)
- Alexandra Schosser
- MRC SGDP Centre, Institute of Psychiatry, King's College London , London , UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Paul J, Zeilhofer HU, Fritschy JM. Selective distribution of GABA(A) receptor subtypes in mouse spinal dorsal horn neurons and primary afferents. J Comp Neurol 2013; 520:3895-911. [PMID: 22522945 DOI: 10.1002/cne.23129] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In the spinal cord dorsal horn, presynaptic GABA(A) receptors (GABA(A)Rs) in the terminals of nociceptors as well as postsynaptic receptors in spinal neurons regulate the transmission of nociceptive and somatosensory signals from the periphery. GABA(A)Rs are heterogeneous and distinguished functionally and pharmacologically by the type of α subunit variant they contain. This heterogeneity raises the possibility that GABA(A)R subtypes differentially regulate specific pain modalities. Here, we characterized the subcellular distribution of GABA(A)R subtypes in nociceptive circuits by using immunohistochemistry with subunit-specific antibodies combined with markers of primary afferents and dorsal horn neurons. Confocal laser scanning microscopy analysis revealed a distinct, partially overlapping laminar distribution of α1-3 and α5 subunit immunoreactivity in laminae I-V. Likewise, a layer-specific pattern was evident for their distribution among glutamatergic, γ-aminobutyric acid (GABA)ergic, and glycinergic neurons (detected in transgenic mice expressing vesicular glutamate transporter 2-enhanced green fluorescent protein [vGluT2-eGFP], glutamic acid decarboxylase [GAD]67-eGFP, and glycine transporter 2 (GlyT2)-eGFP, respectively). Finally, all four subunits could be detected within primary afferent terminals. C-fibers predominantly contained either α2 or α3 subunit immunoreactivity; terminals from myelinated (Aβ/Aδ) fibers were colabeled in roughly equal proportion with each subunit. The presence of axoaxonic GABAergic synapses was determined by costaining with gephyrin and vesicular inhibitory amino acid transporter to label GABAergic postsynaptic densities and terminals, respectively. Colocalization of the α2 or α3 subunit with these markers was observed in a subset of C-fiber synapses. Furthermore, gephyrin mRNA and protein expression was detected in dorsal root ganglia. Collectively, these results show that differential GABA(A)R distribution in primary afferent terminals and dorsal horn neurons allows for multiple, circuit-specific modes of regulation of nociceptive circuits.
Collapse
Affiliation(s)
- Jolly Paul
- Institute of Pharmacology and Toxicology, University of Zurich, CH-8057 Zurich, Switzerland
| | | | | |
Collapse
|
44
|
Van Den Bossche MJ, Strazisar M, Cammaerts S, Liekens AM, Vandeweyer G, Depreeuw V, Mattheijssens M, Lenaerts AS, De Zutter S, De Rijk P, Sabbe B, Del-Favero J. Identification of rare copy number variants in high burden schizophrenia families. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:273-82. [PMID: 23505263 DOI: 10.1002/ajmg.b.32146] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 02/13/2013] [Indexed: 11/05/2022]
Abstract
Over the last years, genome-wide studies consistently showed an increased burden of rare copy number variants (CNVs) in schizophrenia patients, supporting the "common disease, rare variant" hypothesis in at least a subset of patients. We hypothesize that in families with a high burden of disease, and thus probably a high genetic load influencing disease susceptibility, rare CNVs might be involved in the etiology of schizophrenia. We performed a genome-wide CNV analysis in the index patients of eight families with multiple schizophrenia affected members, and consecutively performed a detailed family analysis for the most relevant CNVs. One index patient showed a DRD5 containing duplication. A second index patient presented with an NRXN1 containing deletion and two adjacent duplications containing MYT1L and SNTG2. Detailed analysis in the subsequent families showed segregation of the identified CNVs. With this study we show the importance of screening high burden families for rare CNVs, which will not only broaden our knowledge concerning the molecular genetic mechanisms involved in schizophrenia but also allow the use of the obtained genetic data to provide better clinical care to these families in general and to non-symptomatic causal CNV carriers in particular.
Collapse
Affiliation(s)
- Maarten J Van Den Bossche
- Applied Molecular Genomics Group, VIB Department of Molecular Genetics, VIB, Universiteitsplein 1, B-2610 Antwerp, Belgium
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
The dystrophin–glycoprotein complex in brain development and disease. Trends Neurosci 2012; 35:487-96. [DOI: 10.1016/j.tins.2012.04.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 04/03/2012] [Accepted: 04/15/2012] [Indexed: 11/23/2022]
|
46
|
Fritschy JM, Panzanelli P, Tyagarajan SK. Molecular and functional heterogeneity of GABAergic synapses. Cell Mol Life Sci 2012; 69:2485-99. [PMID: 22314501 PMCID: PMC11115047 DOI: 10.1007/s00018-012-0926-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 01/16/2012] [Accepted: 01/19/2012] [Indexed: 01/07/2023]
Abstract
Knowledge of the functional organization of the GABAergic system, the main inhibitory neurotransmitter system, in the CNS has increased remarkably in recent years. In particular, substantial progress has been made in elucidating the molecular mechanisms underlying the formation and plasticity of GABAergic synapses. Evidence available ascribes a key role to the cytoplasmic protein gephyrin to form a postsynaptic scaffold anchoring GABA(A) receptors along with other transmembrane proteins and signaling molecules in the postsynaptic density. However, the mechanisms of gephyrin scaffolding remain elusive, notably because gephyrin can auto-aggregate spontaneously and lacks PDZ protein interaction domains found in a majority of scaffolding proteins. In addition, the structural diversity of GABA(A) receptors, which are pentameric channels encoded by a large family of subunits, has been largely overlooked in these studies. Finally, the role of the dystrophin-glycoprotein complex, present in a subset of GABAergic synapses in cortical structures, remains ill-defined. In this review, we discuss recent results derived mainly from the analysis of mutant mice lacking a specific GABA(A) receptor subtype or a core protein of the GABAergic postsynaptic density (neuroligin-2, collybistin), highlighting the molecular diversity of GABAergic synapses and its relevance for brain plasticity and function. In addition, we discuss the contribution of the dystrophin-glycoprotein complex to the molecular and functional heterogeneity of GABAergic synapses.
Collapse
Affiliation(s)
- Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland.
| | | | | |
Collapse
|
47
|
Rescue of a dystrophin-like protein by exon skipping normalizes synaptic plasticity in the hippocampus of the mdx mouse. Neurobiol Dis 2011; 43:635-41. [DOI: 10.1016/j.nbd.2011.05.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/10/2011] [Accepted: 05/14/2011] [Indexed: 11/19/2022] Open
|
48
|
Panzanelli P, Gunn BG, Schlatter MC, Benke D, Tyagarajan SK, Scheiffele P, Belelli D, Lambert JJ, Rudolph U, Fritschy JM. Distinct mechanisms regulate GABAA receptor and gephyrin clustering at perisomatic and axo-axonic synapses on CA1 pyramidal cells. J Physiol 2011; 589:4959-80. [PMID: 21825022 DOI: 10.1113/jphysiol.2011.216028] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Pyramidal cells express various GABA(A) receptor (GABA(A)R) subtypes, possibly to match inputs from functionally distinct interneurons targeting specific subcellular domains. Postsynaptic anchoring of GABA(A)Rs is ensured by a complex interplay between the scaffolding protein gephyrin, neuroligin-2 and collybistin. Direct interactions between these proteins and GABA(A)R subunits might contribute to synapse-specific distribution of GABA(A)R subtypes. In addition, the dystrophin-glycoprotein complex, mainly localized at perisomatic synapses, regulates GABA(A)R postsynaptic clustering at these sites. Here, we investigated how the functional and molecular organization of GABAergic synapses in CA1 pyramidal neurons is altered in mice lacking the GABA(A)R α2 subunit (α2-KO). We report a marked, layer-specific loss of postsynaptic gephyrin and neuroligin-2 clusters, without changes in GABAergic presynaptic terminals. Whole-cell voltage-clamp recordings in slices from α2-KO mice show a 40% decrease in GABAergic mIPSC frequency, with unchanged amplitude and kinetics. Applying low/high concentrations of zolpidem to discriminate between α1- and α2/α3-GABA(A)Rs demonstrates that residual mIPSCs in α2-KO mice are mediated by α1-GABA(A)Rs. Immunofluorescence analysis reveals maintenance of α1-GABA(A)R and neuroligin-2 clusters, but not gephyrin clusters, in perisomatic synapses of mutant mice, along with a complete loss of these three markers on the axon initial segment. This striking subcellular difference correlates with the preservation of dystrophin clusters, colocalized with neuroligin-2 and α1-GABA(A)Rs on pyramidal cell bodies of mutant mice. Dystrophin was not detected on the axon initial segment in either genotype. Collectively, these findings reveal synapse-specific anchoring of GABA(A)Rs at postsynaptic sites and suggest that the dystrophin-glycoprotein complex contributes to stabilize α1-GABA(A)R and neuroligin-2, but not gephyrin, in perisomatic postsynaptic densities.
Collapse
Affiliation(s)
- Patrizia Panzanelli
- Department of Anatomy, Pharmacology and Forensic Medicine and National Institute of Neuroscience-Italy, University of Turin, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kuzirian MS, Paradis S. Emerging themes in GABAergic synapse development. Prog Neurobiol 2011; 95:68-87. [PMID: 21798307 DOI: 10.1016/j.pneurobio.2011.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/30/2011] [Accepted: 07/03/2011] [Indexed: 12/25/2022]
Abstract
Glutamatergic synapse development has been rigorously investigated for the past two decades at both the molecular and cell biological level yet a comparable intensity of investigation into the cellular and molecular mechanisms of GABAergic synapse development has been lacking until relatively recently. This review will provide a detailed overview of the current understanding of GABAergic synapse development with a particular emphasis on assembly of synaptic components, molecular mechanisms of synaptic development, and a subset of human disorders which manifest when GABAergic synapse development is disrupted. An unexpected and emerging theme from these studies is that glutamatergic and GABAergic synapse development share a number of overlapping molecular and cell biological mechanisms that will be emphasized in this review.
Collapse
Affiliation(s)
- Marissa S Kuzirian
- Brandeis Univeristy, Department of Biology, National Center for Behavioral Genomics, Volen Center for Complex Systems, Waltham, MA 02453, USA
| | | |
Collapse
|
50
|
Luscher B, Fuchs T, Kilpatrick CL. GABAA receptor trafficking-mediated plasticity of inhibitory synapses. Neuron 2011; 70:385-409. [PMID: 21555068 DOI: 10.1016/j.neuron.2011.03.024] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 12/22/2022]
Abstract
Proper developmental, neural cell-type-specific, and activity-dependent regulation of GABAergic transmission is essential for virtually all aspects of CNS function. The number of GABA(A) receptors in the postsynaptic membrane directly controls the efficacy of GABAergic synaptic transmission. Thus, regulated trafficking of GABA(A) receptors is essential for understanding brain function in both health and disease. Here we summarize recent progress in the understanding of mechanisms that allow dynamic adaptation of cell surface expression and postsynaptic accumulation and function of GABA(A) receptors. This includes activity-dependent and cell-type-specific changes in subunit gene expression, assembly of subunits into receptors, as well as exocytosis, endocytic recycling, diffusion dynamics, and degradation of GABA(A) receptors. In particular, we focus on the roles of receptor-interacting proteins, scaffold proteins, synaptic adhesion proteins, and enzymes that regulate the trafficking and function of receptors and associated proteins. In addition, we review neuropeptide signaling pathways that affect neural excitability through changes in GABA(A)R trafficking.
Collapse
Affiliation(s)
- Bernhard Luscher
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
| | | | | |
Collapse
|