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Vacca O, Zarrouki F, Izabelle C, Belmaati Cherkaoui M, Rendon A, Dalkara D, Vaillend C. AAV-Mediated Restoration of Dystrophin-Dp71 in the Brain of Dp71-Null Mice: Molecular, Cellular and Behavioral Outcomes. Cells 2024; 13:718. [PMID: 38667332 PMCID: PMC11049308 DOI: 10.3390/cells13080718] [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: 02/29/2024] [Revised: 04/05/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
A deficiency in the shortest dystrophin-gene product, Dp71, is a pivotal aggravating factor for intellectual disabilities in Duchenne muscular dystrophy (DMD). Recent advances in preclinical research have achieved some success in compensating both muscle and brain dysfunctions associated with DMD, notably using exon skipping strategies. However, this has not been studied for distal mutations in the DMD gene leading to Dp71 loss. In this study, we aimed to restore brain Dp71 expression in the Dp71-null transgenic mouse using an adeno-associated virus (AAV) administrated either by intracardiac injections at P4 (ICP4) or by bilateral intracerebroventricular (ICV) injections in adults. ICP4 delivery of the AAV9-Dp71 vector enabled the expression of 2 to 14% of brain Dp71, while ICV delivery enabled the overexpression of Dp71 in the hippocampus and cortex of adult mice, with anecdotal expression in the cerebellum. The restoration of Dp71 was mostly located in the glial endfeet that surround capillaries, and it was associated with partial localization of Dp71-associated proteins, α1-syntrophin and AQP4 water channels, suggesting proper restoration of a scaffold of proteins involved in blood-brain barrier function and water homeostasis. However, this did not result in significant improvements in behavioral disturbances displayed by Dp71-null mice. The potential and limitations of this AAV-mediated strategy are discussed. This proof-of-concept study identifies key molecular markers to estimate the efficiencies of Dp71 rescue strategies and opens new avenues for enhancing gene therapy targeting cognitive disorders associated with a subgroup of severely affected DMD patients.
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Affiliation(s)
- Ophélie Vacca
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400 Saclay, France (M.B.C.)
| | - Faouzi Zarrouki
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400 Saclay, France (M.B.C.)
| | - Charlotte Izabelle
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400 Saclay, France (M.B.C.)
| | - Mehdi Belmaati Cherkaoui
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400 Saclay, France (M.B.C.)
| | - Alvaro Rendon
- Department of Therapeutics, Sorbonne University, Institut de la Vision, 75012 Paris, France; (A.R.)
| | - Deniz Dalkara
- Department of Therapeutics, Sorbonne University, Institut de la Vision, 75012 Paris, France; (A.R.)
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400 Saclay, France (M.B.C.)
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Gharibi S, Vaillend C, Lindsay A. The unconditioned fear response in vertebrates deficient in dystrophin. Prog Neurobiol 2024; 235:102590. [PMID: 38484964 DOI: 10.1016/j.pneurobio.2024.102590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/31/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024]
Abstract
Dystrophin loss due to mutations in the Duchenne muscular dystrophy (DMD) gene is associated with a wide spectrum of neurocognitive comorbidities, including an aberrant unconditioned fear response to stressful/threat stimuli. Dystrophin-deficient animal models of DMD demonstrate enhanced stress reactivity that manifests as sustained periods of immobility. When the threat is repetitive or severe in nature, dystrophinopathy phenotypes can be exacerbated and even cause sudden death. Thus, it is apparent that enhanced sensitivity to stressful/threat stimuli in dystrophin-deficient vertebrates is a legitimate cause of concern for patients with DMD that could impact neurocognition and pathophysiology. This review discusses our current understanding of the mechanisms and consequences of the hypersensitive fear response in preclinical models of DMD and the potential challenges facing clinical translatability.
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Affiliation(s)
- Saba Gharibi
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, Saclay 91400, France.
| | - Angus Lindsay
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia; School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand; Department of Medicine, University of Otago, Christchurch 8014, New Zealand.
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Bonosi L, Benigno UE, Musso S, Giardina K, Gerardi RM, Brunasso L, Costanzo R, Paolini F, Buscemi F, Avallone C, Gulino V, Iacopino DG, Maugeri R. The Role of Aquaporins in Epileptogenesis-A Systematic Review. Int J Mol Sci 2023; 24:11923. [PMID: 37569297 PMCID: PMC10418736 DOI: 10.3390/ijms241511923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/13/2023] Open
Abstract
Aquaporins (AQPs) are a family of membrane proteins involved in the transport of water and ions across cell membranes. AQPs have been shown to be implicated in various physiological and pathological processes in the brain, including water homeostasis, cell migration, and inflammation, among others. Epileptogenesis is a complex and multifactorial process that involves alterations in the structure and function of neuronal networks. Recent evidence suggests that AQPs may also play a role in the pathogenesis of epilepsy. In animal models of epilepsy, AQPs have been shown to be upregulated in regions of the brain that are involved in seizure generation, suggesting that they may contribute to the hyperexcitability of neuronal networks. Moreover, genetic studies have identified mutations in AQP genes associated with an increased risk of developing epilepsy. Our review aims to investigate the role of AQPs in epilepsy and seizure onset from a pathophysiological point of view, pointing out the potential molecular mechanism and their clinical implications.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Rosario Maugeri
- Neurosurgical Clinic, AOUP “Paolo Giaccone”, Post Graduate Residency Program in Neurologic Surgery, Department of Biomedicine Neurosciences and Advanced Diagnostics, School of Medicine, University of Palermo, 90127 Palermo, Italy; (L.B.); (U.E.B.); (S.M.); (K.G.); (R.M.G.); (L.B.); (R.C.); (F.P.); (F.B.); (C.A.); (V.G.); (D.G.I.)
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Dystrophin Short Product, Dp71, Interacts with AQP4 and Kir4.1 Channels in the Mouse Cerebellar Glial Cells in Contrast to Dp427 at Inhibitory Postsynapses in the Purkinje Neurons. Mol Neurobiol 2023; 60:3664-3677. [PMID: 36918517 DOI: 10.1007/s12035-023-03296-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 03/01/2023] [Indexed: 03/16/2023]
Abstract
Dystrophin is the causative gene for Duchenne and Becker muscular dystrophy (DMD/BMD), and it produces full-length and short dystrophin, Dp427 and Dp71, respectively, in the brain. The existence of the different dystrophin molecular complexes has been known for a quarter century, so it is necessary to derive precise expression profiles of the molecular complexes in the brain to elucidate the mechanism of cognitive symptoms in DMD/BMD patients. In order to investigate the Dp71 expression profile in cerebellum, we employed Dp71-specific tag-insertion mice, which allowed for the specific detection of endogenous Dp71 in the immunohistochemical analysis and found its expressions in the glial cells, Bergmann glial (BG) cells, and astrocytes, whereas Dp427 was exclusively expressed in the inhibitory postsynapses within cerebellar Purkinje cells (PCs). Interestingly, we found different cell-type dependent dystrophin molecular complexes; i.e., glia-associated Dp71 was co-expressed with dystroglycan (DG) and dystrobrevinα, whereas synapse-associated Dp427 was co-expressed with DG and dystrobrevinβ. Furthermore, we investigated the molecular relationship of Dp71 to the AQP4 water channel and the Kir4.1 potassium channel, and found biochemical associations of Dp71 with AQP4 and Kir4.1 in both the cerebellum and cerebrum. Immunohistochemical and cytochemical investigations revealed partial co-localizations of Dp71 with AQP4 and Kir4.1 in the glial cells, indicating Dp71 interactions with the channels in the BG cells and astrocytes. Taken together, different cell-types, glial cells and Purkinje neurons, in the cerebellum express different dystrophin molecular complexes, which may contribute to pathological and physiological processes through the regulation of the water/ion channel and inhibitory postsynapses.
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Barboni MTS, Joachimsthaler A, Roux MJ, Nagy ZZ, Ventura DF, Rendon A, Kremers J, Vaillend C. Retinal dystrophins and the retinopathy of Duchenne muscular dystrophy. Prog Retin Eye Res 2022:101137. [DOI: 10.1016/j.preteyeres.2022.101137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/25/2022] [Accepted: 11/03/2022] [Indexed: 11/21/2022]
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Diabetic Macular Edema: Current Understanding, Molecular Mechanisms and Therapeutic Implications. Cells 2022; 11:cells11213362. [PMID: 36359761 PMCID: PMC9655436 DOI: 10.3390/cells11213362] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 11/24/2022] Open
Abstract
Diabetic retinopathy (DR), with increasing incidence, is the major cause of vision loss and blindness worldwide in working-age adults. Diabetic macular edema (DME) remains the main cause of vision impairment in diabetic patients, with its pathogenesis still not completely elucidated. Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of DR and DME. Currently, intravitreal injection of anti-VEGF agents remains as the first-line therapy in DME treatment due to the superior anatomic and functional outcomes. However, some patients do not respond satisfactorily to anti-VEGF injections. More than 30% patients still exist with persistent DME even after regular intravitreal injection for at least 4 injections within 24 weeks, suggesting other pathogenic factors, beyond VEGF, might contribute to the pathogenesis of DME. Recent advances showed nearly all the retinal cells are involved in DR and DME, including breakdown of blood-retinal barrier (BRB), drainage dysfunction of Müller glia and retinal pigment epithelium (RPE), involvement of inflammation, oxidative stress, and neurodegeneration, all complicating the pathogenesis of DME. The profound understanding of the changes in proteomics and metabolomics helps improve the elucidation of the pathogenesis of DR and DME and leads to the identification of novel targets, biomarkers and potential therapeutic strategies for DME treatment. The present review aimed to summarize the current understanding of DME, the involved molecular mechanisms, and the changes in proteomics and metabolomics, thus to propose the potential therapeutic recommendations for personalized treatment of DME.
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Insight into the Mammalian Aquaporin Interactome. Int J Mol Sci 2022; 23:ijms23179615. [PMID: 36077012 PMCID: PMC9456110 DOI: 10.3390/ijms23179615] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/16/2022] [Accepted: 08/22/2022] [Indexed: 01/07/2023] Open
Abstract
Aquaporins (AQPs) are a family of transmembrane water channels expressed in all living organisms. AQPs facilitate osmotically driven water flux across biological membranes and, in some cases, the movement of small molecules (such as glycerol, urea, CO2, NH3, H2O2). Protein-protein interactions play essential roles in protein regulation and function. This review provides a comprehensive overview of the current knowledge of the AQP interactomes and addresses the molecular basis and functional significance of these protein-protein interactions in health and diseases. Targeting AQP interactomes may offer new therapeutic avenues as targeting individual AQPs remains challenging despite intense efforts.
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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.
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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
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9
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Netti V, Fernández J, Melamud L, Garcia-Miranda P, Di Giusto G, Ford P, Echevarría M, Capurro C. Aquaporin-4 Removal from the Plasma Membrane of Human Müller Cells by AQP4-IgG from Patients with Neuromyelitis Optica Induces Changes in Cell Volume Homeostasis: the First Step of Retinal Injury? Mol Neurobiol 2021; 58:5178-5193. [PMID: 34263427 DOI: 10.1007/s12035-021-02491-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/11/2021] [Indexed: 11/27/2022]
Abstract
Aquaporin-4 (AQP4) is the target of the specific immunoglobulin G autoantibody (AQP4-IgG) produced in patients with neuromyelitis optica spectrum disorders (NMOSD). Previous studies demonstrated that AQP4-IgG binding to astrocytic AQP4 leads to cell-destructive lesions. However, the early physiopathological events in Müller cells in the retina are poorly understood. Here, we investigated the consequences of AQP4-IgG binding to AQP4 of Müller cells, previous to the inflammatory response, on two of AQP4's key functions, cell volume regulation response (RVD) and cell proliferation, a process closely associated with changes in cell volume. Experiments were performed in a human retinal Müller cell line (MIO-M1) exposed to complement-inactivated sera from healthy volunteers or AQP4-IgG positive NMOSD patients. We evaluated AQP4 expression (immunofluorescence and western blot), water permeability coefficient, RVD, intracellular calcium levels and membrane potential changes during hypotonic shock (fluorescence videomicroscopy) and cell proliferation (cell count and BrdU incorporation). Our results showed that AQP4-IgG binding to AQP4 induces its partial internalization, leading to the decrease of the plasma membrane water permeability, a reduction of swelling-induced increase of intracellular calcium levels and the impairment of RVD in Müller cells. The loss of AQP4 from the plasma membrane induced by AQP4-IgG positive sera delayed Müller cells' proliferation rate. We propose that Müller cell dysfunction after AQP4 removal from the plasma membrane by AQP4-IgG binding could be a non-inflammatory mechanism of retinal injury in vivo, altering cell volume homeostasis and cell proliferation and consequently, contributing to the physiopathology of NMOSD.
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Affiliation(s)
- Vanina Netti
- Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Facultad de Medicina, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO-HOUSSAY), Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Juan Fernández
- Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Facultad de Medicina, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO-HOUSSAY), Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Luciana Melamud
- Servicio de Neurología, Centro Universitario de Neurología Dr. J.M. Ramos Mejía, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pablo Garcia-Miranda
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Universidad de Sevilla, Seville, Spain
| | - Gisela Di Giusto
- Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Facultad de Medicina, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO-HOUSSAY), Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula Ford
- Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Facultad de Medicina, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO-HOUSSAY), Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Miriam Echevarría
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Universidad de Sevilla, Seville, Spain
| | - Claudia Capurro
- Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Facultad de Medicina, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO-HOUSSAY), Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina.
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Wang T, Zhang C, Xie H, Jiang M, Tian H, Lu L, Xu GT, Liu L, Zhang J. Anti-VEGF therapy prevents Müller intracellular edema by decreasing VEGF-A in diabetic retinopathy. EYE AND VISION 2021; 8:13. [PMID: 33865457 PMCID: PMC8053282 DOI: 10.1186/s40662-021-00237-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 03/18/2021] [Indexed: 02/07/2023]
Abstract
Background Although vascular endothelial growth factor A (VEGF-A) is known to play a key role in causing retinal edema, whether and how VEGF-A induces intracellular edema in the retina still remains unclear. Methods Sprague-Dawley rats were rendered diabetic with intraperitoneal injection of streptozotocin. Intravitreal injection of ranibizumab was performed 8 weeks after diabetes onset. rMC-1 cells (rat Müller cell line) were treated with glyoxal for 24 h with or without ranibizumab. The expression levels of inwardly rectifying K+ channel 4.1 (Kir4.1), aquaporin 4 (AQP4), Dystrophin 71 (Dp71), VEGF-A, glutamine synthetase (GS) and sodium-potassium-ATPase (Na+-K+-ATPase) were examined using Western blot. VEGF-A in the supernatant of the cell culture was detected with ELISA. The intracellular potassium and sodium levels were detected with specific indicators. Results Compared with normal control, protein expressions of Kir4.1 and AQP4 were down-regulated significantly in diabetic rat retinas, which were prevented by ranibizumab. The above changes were recapitulated in vitro. Similarly, the intracellular potassium level in glyoxal-treated rMC-1 cells was increased, while the intracellular sodium level and Na+-K+-ATPase protein level remained unchanged, compared with control. However, ranibizumab treatment decreased intracellular sodium, but not potassium. Conclusion Ranibizumab protected Müller cells from diabetic intracellular edema through the up-regulation of Kir4.1 and AQP4 by directly binding VEGF-A. It also caused a reduction in intracellular osmotic pressure.
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Affiliation(s)
- Tianqin Wang
- Department of Ophthalmology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong New District, Shanghai, 200127, China
| | - Chaoyang Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, 100 Haining Road, Hongkou District, Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Hai Xie
- Tongji Eye Institute, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 623, Shanghai, 200092, China
| | - Mengmeng Jiang
- Department of Ophthalmology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong New District, Shanghai, 200127, China
| | - Haibin Tian
- Tongji Eye Institute, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 623, Shanghai, 200092, China
| | - Lixia Lu
- Tongji Eye Institute, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 623, Shanghai, 200092, China
| | - Guo-Tong Xu
- Tongji Eye Institute, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 623, Shanghai, 200092, China.
| | - Lin Liu
- Department of Ophthalmology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong New District, Shanghai, 200127, China.
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, 100 Haining Road, Hongkou District, Shanghai, 200080, China. .,National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China.
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Yablonka-Reuveni Z, Stockdale F, Nudel U, Israeli D, Blau HM, Shainberg A, Neuman S, Kessler-Icekson G, Krull EM, Paterson B, Fuchs OS, Greenberg D, Sarig R, Halevy O, Ozawa E, Katcoff DJ. Farewell to Professor David Yaffe - A pillar of the myogenesis field. Eur J Transl Myol 2020; 30:9306. [PMID: 33117511 PMCID: PMC7582454 DOI: 10.4081/ejtm.2020.9306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
It is with great sadness that we have learned about the passing of Professor David Yaffe (1929-2020, Israel). Yehi Zichro Baruch - May his memory be a blessing. David was a man of family, science and nature. A native of Israel, David grew up in the historic years that preceded the birth of the State of Israel. He was a member of the group that established Kibbutz Revivim in the Negev desert, and in 1948 participated in Israel's War of Independence. David and Ruth eventually joined Kibbutz Givat Brenner by Rehovot, permitting David to be both a kibbutz member and a life-long researcher at the Weizmann Institute of Science, where David received his PhD in 1959. David returned to the Institute after his postdoc at Stanford. Here, after several years of researching a number of tissues as models for studying the process of differentiation, David entered the myogenesis field and stayed with it to his last day. With his dedication to the field of myogenesis and his commitment to furthering the understanding of the People and the Land of Israel throughout the international scientific community, David organized the first ever myogenesis meeting that took place in Shoresh, Israel in 1975. This was followed by the 1980 myogenesis meeting at the same place and many more outstanding meetings, all of which brought together myogenesis, nature and scenery. Herein, through the preparation and publication of this current manuscript, we are meeting once again at a "David Yaffe myogenesis meeting". Some of us have been members of the Yaffe lab, some of us have known David as his national and international colleagues in the myology field. One of our contributors has also known (and communicates here) about David Yaffe's earlier years as a kibbutznick in the Negev. Our collective reflections are a tribute to Professor David Yaffe. We are fortunate that the European Journal of Translational Myology has provided us with tremendous input and a platform for holding this 2020 distance meeting "Farwell to Professor David Yaffe - A Pillar of the Myogenesis Field".
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Affiliation(s)
- Zipora Yablonka-Reuveni
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA, USA
| | | | - Uri Nudel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | | | - Helen M Blau
- Stanford University School of Medicine, Institute for Stem Cell Biology and Regenerative Medicine, Department of Microbiology and Immunology, Clinical Sciences Research Center, Stanford, CA, USA
| | - Asher Shainberg
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Gania Kessler-Icekson
- Laboratory of Cellular and Molecular Cardiology, Felsenstein Medical Research Center, Rabin Medical Center, Petah-Tikva, and Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | | | - Bruce Paterson
- Laboratory of Biochemistry and Molecular Biology, National Institutes of Health, Bethesda, Maryland, USA
| | | | - David Greenberg
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Sarig
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Orna Halevy
- Faculty of Agriculture, The Hebrew University, Rehovot, Israel
| | - Eijiro Ozawa
- National Institute of Neuroscience, NCNP, Tokyo, Japan
| | - Don J Katcoff
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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12
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Barboni MTS, Vaillend C, Joachimsthaler A, Liber AMP, Khabou H, Roux MJ, Vacca O, Vignaud L, Dalkara D, Guillonneau X, Ventura DF, Rendon A, Kremers J. Rescue of Defective Electroretinographic Responses in Dp71-Null Mice With AAV-Mediated Reexpression of Dp71. Invest Ophthalmol Vis Sci 2020; 61:11. [PMID: 32049345 PMCID: PMC7326481 DOI: 10.1167/iovs.61.2.11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose To study the potential effect of a gene therapy, designed to rescue the expression of dystrophin Dp71 in the retinas of Dp71-null mice, on retinal physiology. Methods We recorded electroretinograms (ERGs) in Dp71-null and wild-type littermate mice. In dark-adapted eyes, responses to flashes of several strengths were measured. In addition, flash responses on a 25-candela/square meters background were measured. On- and Off-mediated responses to sawtooth stimuli and responses to photopic sine-wave modulation (3–30 Hz) were also recorded. After establishing the ERG phenotype, the ShH10-GFP adeno-associated virus (AAV), which has been previously shown to target specifically Müller glial cells (MGCs), was delivered intravitreously with or without (sham therapy) the Dp71 coding sequence under control of a CBA promoter. ERG recordings were repeated three months after treatment. Real-time quantitative PCR and Western blotting analyses were performed in order to quantify Dp71 expression in the retinas. Results Dp71-null mice displayed reduced b-waves in dark- and light-adapted flash ERGs and smaller response amplitudes to photopic rapid-on sawtooth modulation and to sine-wave stimuli. Three months after intravitreal injections of the ShH10-GFP-2A-Dp71 AAV vector, ERG responses were completely recovered in treated eyes of Dp71-null mice. The functional rescue was associated with an overexpression of Dp71 in treated retinas. Conclusions The present results show successful functional recovery accompanying the reexpression of Dp71. In addition, this experimental model sheds light on MGCs influencing ERG components, since previous reports showed that aquaporin 4 and Kir4.1 channels were mislocated in MGCs of Dp71-null mice, while their distribution could be normalized following intravitreal delivery of the same ShH10-GFP-2A-Dp71 vector.
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13
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Katoozi S, Rao SB, Skauli N, Froehner SC, Ottersen OP, Adams ME, Amiry-Moghaddam M. Functional specialization of retinal Müller cell endfeet depends on an interplay between two syntrophin isoforms. Mol Brain 2020; 13:40. [PMID: 32178707 PMCID: PMC7074989 DOI: 10.1186/s13041-020-00581-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/06/2020] [Indexed: 11/10/2022] Open
Abstract
Retinal Müller cells are highly polarized macroglial cells with accumulation of the aquaporin-4 (AQP4) water channel and the inwardly rectifying potassium channel Kir4.1 at specialized endfoot membrane domains abutting microvessels and corpus vitreum. Proper water and potassium homeostasis in retina depends on these membrane specializations. Here we show that targeted deletion of β1-syntrophin leads to a partial loss of AQP4 from perivascular Müller cell endfeet and that a concomitant deletion of both α1- and β1-syntrophin causes a near complete loss of AQP4 from both perivascular and subvitreal endfoot membranes. α1-syntrophin is normally very weakly expressed in Müller cell endfeet but β1-syntrophin knockout mice display an increased amount of α1-syntrophin at these sites. We suggest that upregulation of perivascular α1-syntrophin restricts the effect of β1-syntrophin deletion. The present findings indicate that β1-syntrophin plays an important role in maintaining the functional polarity of Müller cells and that α1-syntrophin can partially substitute for β1-syntrophin in AQP4 anchoring. Functional polarization of Müller cells thus depends on an interplay between two syntrophin isoforms.
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Affiliation(s)
- Shirin Katoozi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Shreyas B Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195-7290, USA
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway.,Present Address: President's office, Karolinska Institutet, Nobels väg 6, 171 77, Stockholm, Sweden
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195-7290, USA
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway.
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14
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Naidoo M, Anthony K. Dystrophin Dp71 and the Neuropathophysiology of Duchenne Muscular Dystrophy. Mol Neurobiol 2020; 57:1748-1767. [PMID: 31836945 PMCID: PMC7060961 DOI: 10.1007/s12035-019-01845-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by frameshift mutations in the DMD gene that prevent the body-wide translation of its protein product, dystrophin. Besides a severe muscle phenotype, cognitive impairment and neuropsychiatric symptoms are prevalent. Dystrophin protein 71 (Dp71) is the major DMD gene product expressed in the brain and mutations affecting its expression are associated with the DMD neuropsychiatric syndrome. As with dystrophin in muscle, Dp71 localises to dystrophin-associated protein complexes in the brain. However, unlike in skeletal muscle; in the brain, Dp71 is alternatively spliced to produce many isoforms with differential subcellular localisations and diverse cellular functions. These include neuronal differentiation, adhesion, cell division and excitatory synapse organisation as well as nuclear functions such as nuclear scaffolding and DNA repair. In this review, we first describe brain involvement in DMD and the abnormalities observed in the DMD brain. We then review the gene expression, RNA processing and functions of Dp71. We review genotype-phenotype correlations and discuss emerging cellular/tissue evidence for the involvement of Dp71 in the neuropathophysiology of DMD. The literature suggests changes observed in the DMD brain are neurodevelopmental in origin and that their risk and severity is associated with a cumulative loss of distal DMD gene products such as Dp71. The high risk of neuropsychiatric syndromes in Duchenne patients warrants early intervention to achieve the best possible quality of life. Unravelling the function and pathophysiological significance of dystrophin in the brain has become a high research priority to inform the development of brain-targeting treatments for Duchenne.
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Affiliation(s)
- Michael Naidoo
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK
| | - Karen Anthony
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK.
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15
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Ruggieri S, De Giorgis M, Annese T, Tamma R, Notarangelo A, Marzullo A, Senetta R, Cassoni P, Notarangelo M, Ribatti D, Nico B. Dp71 Expression in Human Glioblastoma. Int J Mol Sci 2019; 20:E5429. [PMID: 31683640 PMCID: PMC6862465 DOI: 10.3390/ijms20215429] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/14/2019] [Accepted: 10/30/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Dp71 is the most abundant dystrophin (DMD) gene product in the nervous system. Mutation in the Dp71 coding region is associated with cognitive disturbances in Duchenne muscular dystrophy (DMD) patients, but the function of dystrophin Dp71 in tumor progression remains to be established. This study investigated Dp71 expression in glioblastoma, the most common and aggressive primary tumor of the central nervous system (CNS). METHODS Dp71 expression was analyzed by immunofluorescence, immunohistochemistry, RT-PCR, and immunoblotting in glioblastoma cell lines and cells isolated from human glioblastoma multiforme (GBM) bioptic specimens. RESULTS Dp71 isoform was expressed in normal human astrocytes (NHA) cell lines and decreased in glioblastoma cell lines and cells isolated from human glioblastoma multiforme bioptic specimens. Moreover, Dp71 was localized in the nucleus in normal cells, while it was localized into the cytoplasm of glioblastoma cells organized in clusters. We have shown, by double labeling, that Dp71 colocalizes with lamin B in normal astrocytes cells, confirming the roles of Dp71 and lamin B in maintaining nuclear architecture. Finally, we demonstrated that decreased Dp71 protein in cells isolated from human bioptic specimens was inversely correlated with the Ki-67 tumor proliferative index. CONCLUSION A decreased Dp71 expression is associated with cancer proliferation and poor prognosis in glioblastoma.
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Affiliation(s)
- Simona Ruggieri
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Michelina De Giorgis
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Angelo Notarangelo
- Medical Genetic Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, 71013 Foggia, Italy.
| | - Andrea Marzullo
- Department of Emergency and Transplantation, Pathology Unit, University of Bari Medical School, 70124 Bari, Italy.
| | - Rebecca Senetta
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Paola Cassoni
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Michela Notarangelo
- Centre for Integrative Biology, CIBIO, University of Trento, 38123 Trento, Italy.
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
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16
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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: 9] [Impact Index Per Article: 1.8] [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.
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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
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17
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Zhang Y, Sun L, Liu E, Wang A, Yan J. The olfactory stimulation slows down the substance clearance in the extracellular space of the hippocampus in rat brain. Biochem Biophys Res Commun 2019; 515:429-435. [PMID: 31155295 DOI: 10.1016/j.bbrc.2019.05.159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 05/26/2019] [Indexed: 12/25/2022]
Abstract
Accelerating the clearance of toxin in the brain extracellular space (ECS) has grown a promising strategy for treating some central nervous system diseases. As oldest sensory system, we know little about the influence of olfaction on the brain, but preclinical studies such as treatment of neurological diseases through it are in the ascendant. This makes it important to clarify the effects of olfaction on brain ECS and interstitial fluid (ISF) drainage. In this study, the effect of olfactory stimulation (eugenol, EUG) on ISF flow in hippocampus and its association with aquaporin 4 (Aqp4) had been investigated. The results show that eugenol can significantly increase the activity of hippocampal neurons, but reduce the clearance and diffusion rates of Gd-DTPA and A-594 in hippocampus. Similarly, eugenol inhalation slows down the rate of Gd-DTPA in CSF entering the hippocampus and its clearance. And knockout of Aqp4 gene aggravated these processes. In vitro results showed that after Aqp4 gene silencing, astrocytes grew slowly, with significantly decreased cells number, less nuclei, atrophied bodies and shorter processes. These results concluded that olfactory stimulation can change the ECS structure of the hippocampus, slow down the ISF drainage, and improve the function of neurons, while Aqp4 plays important roles.
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Affiliation(s)
- Yixuan Zhang
- Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Linlin Sun
- Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - E Liu
- Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Aibo Wang
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China; Beijing Key Lab of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Junhao Yan
- Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China; Beijing Key Lab of Magnetic Resonance Imaging Technology, Beijing, 100191, China.
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18
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Benabdesselam R, Rendon A, Dorbani-Mamine L, Hardin-Pouzet H. Effect of Dp71 deficiency on the oxytocin hypothalamic axis in osmoregulation function in mice. Acta Histochem 2019; 121:268-276. [PMID: 30642627 DOI: 10.1016/j.acthis.2019.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/30/2018] [Accepted: 01/03/2019] [Indexed: 11/25/2022]
Abstract
Dp71 is the major form of dystrophins (Dp) in the supraoptic nucleus (SON) and in the neural lobe of hypophysis (NL/HP). Dp71-null mice exhibit a hypo-osmolar status attributed to an altered osmosensitivity of the SON and to a perturbed vasopressinergic axis. Because oxytocin (OT) is implicated in osmoregulation via natriuresis, this study explored the oxytocinergic axis in Dp71-null mice after salt-loading (SL). Under normosmolar conditions, OT-mRNA expression was higher in the Dp71-null SON compared to wild-type (wt) and the OT peptide level has not changed. Dp-immunostaining was localized in astrocytes end-feet surrounding vessels in wt SON. This distribution changed in Dp71-null SON, Dp being detected in OT-soma of MCNs. nNOS and NADPH-diaphorase levels increased in the OT area of the Dp71-null SON compared to wt. In the NL/HP, OT level reduced in Dp71-null mice and Dp localization changed from pituicytes end-feet in wt SON to OT terminals in Dp71-null SON. Salt-Loading resulted in an increase of OT-mRNA and peptide levels in wt SON but had no effect in Dp71-null SON. In the NL/HP, OT content was reduced after SL. For Dp71-null mice, OT level, already low in control, was not modified by SL. Dp level was not affected by SL in the SON nor in the NL/HP. Our data confirmed the importance of Dp71 for the SON functionality in osmoregulation. The localization of Dp71 at the glial-vascular interface could be associated with SON osmosensitivity, leading to an adequate OT synthesis in the SON and release from the NL/HP upon plasmatic hyperosmolality.
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19
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Rao SB, Katoozi S, Skauli N, Froehner SC, Ottersen OP, Adams ME, Amiry-Moghaddam M. Targeted deletion of β1-syntrophin causes a loss of K ir 4.1 from Müller cell endfeet in mouse retina. Glia 2019; 67:1138-1149. [PMID: 30803043 DOI: 10.1002/glia.23600] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 02/02/2023]
Abstract
Proper function of the retina depends heavily on a specialized form of retinal glia called Müller cells. These cells carry out important homeostatic functions that are contingent on their polarized nature. Specifically, the Müller cell endfeet that contact retinal microvessels and the corpus vitreum show a tenfold higher concentration of the inwardly rectifying potassium channel Kir 4.1 than other Müller cell plasma membrane domains. This highly selective enrichment of Kir 4.1 allows K+ to be siphoned through endfoot membranes in a special form of spatial buffering. Here, we show that Kir 4.1 is enriched in endfoot membranes through an interaction with β1-syntrophin. Targeted disruption of this syntrophin caused a loss of Kir 4.1 from Müller cell endfeet without affecting the total level of Kir 4.1 expression in the retina. Targeted disruption of α1-syntrophin had no effect on Kir 4.1 localization. Our findings show that the Kir 4.1 aggregation that forms the basis for K+ siphoning depends on a specific syntrophin isoform that colocalizes with Kir 4.1 in Müller endfoot membranes.
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Affiliation(s)
- Shreyas B Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Shirin Katoozi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, Western Australia
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, Western Australia
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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20
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Souttou S, Benabdesselam R, Siqueiros-Marquez L, Sifi M, Deliba M, Vacca O, Charles-Messance H, Vaillend C, Rendon A, Guillonneau X, Dorbani-Mamine L. Expression and localization of dystrophins and β-dystroglycan in the hypothalamic supraoptic nuclei of rat from birth to adulthood. Acta Histochem 2019; 121:218-226. [PMID: 30595391 DOI: 10.1016/j.acthis.2018.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/19/2018] [Accepted: 12/10/2018] [Indexed: 10/27/2022]
Abstract
Dystrophins (Dps) are the sub-membranous proteins that work via the dystrophin-associated proteins complex, which comprises β-dystroglycan (β-DG), a cell surface receptor for extracellular matrix. Recently, we have revealed β-DG decrease and central function impairment of supraoptic nucleus (SON) in Dp71 deficient adult mice, opening the question on the profiles of Dps and β-DG during SON development. At birth and the age of 10, 20 and 60 days, we examined the expression by RT-PCR and Western-blotting, and the distribution by immunohistochemistry of Dps and β-DG. Also, we analyzed, by immunohistochemistry and Western-blotting, the neuropeptide, arginine vasopressin (AVP), in the SON at the different ages. At birth, Dp71 and to a lesser extends, Dp140 and Dp427, and also β-DG are revealed in the SON. They are localized in the magnocellular neurons (MCNs), astrocytes and vessels. From birth to adulthood, the AVP raise in the SON coincides with the progressive increase of Dp71 level while the level of Dp140 and Dp427 increased only at D20, D10 post-natal development, respectively, and β-DG expression did not change. Moreover, the location of Dps or/and β-DG in the cell compartments was modified during development: at D10, Dps appeared in the astrocytes end-feet surrounding MCNs, and at D20, Dps and β-DG codistributed in the astrocytes end-feet, surrounding MCNs and vessels. Such a distribution marks the first steps of post-natal SON development and may be considered essential in the establishment of structural plasticity mechanisms in SON, where astrocyte end-feet, vessels, magnocellular neurons, are physiologically associated. The disappearance of β-DG in the MCNs nucleus marks the adulthood SON and suggests that the complex of Dps associating β-DG is required for the nucleoskeleton function in the post-natal development.
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21
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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: 45] [Impact Index Per Article: 7.5] [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.
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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
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22
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Chaussenot R, Amar M, Fossier P, Vaillend C. Dp71-Dystrophin Deficiency Alters Prefrontal Cortex Excitation-Inhibition Balance and Executive Functions. Mol Neurobiol 2018; 56:2670-2684. [PMID: 30051354 DOI: 10.1007/s12035-018-1259-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/17/2018] [Indexed: 01/19/2023]
Abstract
In the Duchenne muscular dystrophy (DMD) syndrome, mutations affecting expression of Dp71, the main dystrophin isoform of the multipromoter dmd gene in brain, have been associated with intellectual disability and neuropsychiatric disturbances. Patients' profile suggests alterations in prefrontal cortex-dependent executive processes, but the specific dysfunctions due to Dp71 deficiency are unclear. Dp71 is involved in brain ion homeostasis, and its deficiency is expected to increase neuronal excitability, which might compromise the integrity of neuronal networks undertaking high-order cognitive functions. Here, we used electrophysiological (patch clamp) and behavioral techniques in a transgenic mouse that display a selective loss of Dp71 and no muscular dystrophy, to identify changes in prefrontal cortex excitatory/inhibitory (E/I) balance and putative executive dysfunctions. We found prefrontal cortex E/I balance is shifted toward enhanced excitation in Dp71-null mice. This is associated with a selective alteration of AMPA receptor-mediated glutamatergic transmission and reduced synaptic plasticity, while inhibitory transmission is unaffected. Moreover, Dp71-null mice display deficits in cognitive processes that depend on prefrontal cortex integrity, such as cognitive flexibility and sensitivity of spatial working memory to proactive interference. Our data suggest that impaired cortical E/I balance and executive dysfunctions contribute to the intellectual and behavioral disturbances associated with Dp71 deficiency in DMD, in line with current neurobehavioral models considering these functions as key pathophysiological factors in various neurodevelopmental disorders. These new insights in DMD neurobiology also suggest new directions for therapeutic developments targeting excitatory neurotransmission, as well as for guidance of academic environment in severely affected DMD children.
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Affiliation(s)
- Rémi Chaussenot
- Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, Orsay, France
| | - Muriel Amar
- Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, Orsay, France.,Laboratoire de Toxinologie moléculaire et Biotechnologies, Institut des Sciences du Vivant Frédéric Joliot, CEA de Saclay, 91191, Gif-sur-Yvette, France
| | - Philippe Fossier
- Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, Orsay, France
| | - Cyrille Vaillend
- Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, Orsay, France.
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23
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Helleringer R, Le Verger D, Li X, Izabelle C, Chaussenot R, Belmaati-Cherkaoui M, Dammak R, Decottignies P, Daniel H, Galante M, Vaillend C. Cerebellar synapse properties and cerebellum-dependent motor and non-motor performance in Dp71-null mice. Dis Model Mech 2018; 11:dmm.033258. [PMID: 29895670 PMCID: PMC6078407 DOI: 10.1242/dmm.033258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 06/04/2018] [Indexed: 02/04/2023] Open
Abstract
Recent emphasis has been placed on the role that cerebellar dysfunctions could have in the genesis of cognitive deficits in Duchenne muscular dystrophy (DMD). However, relevant genotype-phenotype analyses are missing to define whether cerebellar defects underlie the severe cases of intellectual deficiency that have been associated with genetic loss of the smallest product of the dmd gene, the Dp71 dystrophin. To determine for the first time whether Dp71 loss could affect cerebellar physiology and functions, we have used patch-clamp electrophysiological recordings in acute cerebellar slices and a cerebellum-dependent behavioral test battery addressing cerebellum-dependent motor and non-motor functions in Dp71-null transgenic mice. We found that Dp71 deficiency selectively enhances excitatory transmission at glutamatergic synapses formed by climbing fibers (CFs) on Purkinje neurons, but not at those formed by parallel fibers. Altered basal neurotransmission at CFs was associated with impairments in synaptic plasticity and clustering of the scaffolding postsynaptic density protein PSD-95. At the behavioral level, Dp71-null mice showed some improvements in motor coordination and were unimpaired for muscle force, static and dynamic equilibrium, motivation in high-motor demand and synchronization learning. Dp71-null mice displayed altered strategies in goal-oriented navigation tasks, however, suggesting a deficit in the cerebellum-dependent processing of the procedural components of spatial learning, which could contribute to the visuospatial deficits identified in this model. In all, the observed deficits suggest that Dp71 loss alters cerebellar synapse function and cerebellum-dependent navigation strategies without being detrimental for motor functions. Summary: Dp71 is the most prominent dystrophin gene product in the adult brain. Here, multiple approaches including behavioral tests and electrophysiology are adopted to explore the role of Dp71 in the cerebellum.
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Affiliation(s)
- Romain Helleringer
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Delphine Le Verger
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Xia Li
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Charlotte Izabelle
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Rémi Chaussenot
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Mehdi Belmaati-Cherkaoui
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Raoudha Dammak
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Paulette Decottignies
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Hervé Daniel
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Micaela Galante
- Molecules and Circuits Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Cyrille Vaillend
- Cognition and Behavior Department, Paris-Saclay Institute of Neuroscience (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91405 Orsay, France
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24
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Abstract
Epilepsy is among the most prevalent chronic neurological diseases and affects an estimated 2.2 million people in the United States alone. About one third of patients are resistant to currently available antiepileptic drugs, which are exclusively targeting neuronal function. Yet, reactive astrocytes have emerged as potential contributors to neuronal hyperexcitability and seizures. Astrocytes react to any kind of CNS insult with a range of cellular adjustments to form a scar and protect uninjured brain regions. This process changes astrocyte physiology and can affect neuronal network function in various ways. Traumatic brain injury and stroke, both conditions that trigger astroglial scar formation, are leading causes of acquired epilepsies and surgical removal of this glial scar in patients with drug-resistant epilepsy can alleviate the seizures. This review will summarize the currently available evidence suggesting that epilepsy is not a disease of neurons alone, but that astrocytes, glial cells in the brain, can be major contributors to the disease, especially when they adopt a reactive state in response to central nervous system insult.
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Affiliation(s)
- Stefanie Robel
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA
- Virginia Tech School of Neuroscience, Blacksburg, VA, USA
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25
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Vacca O, Charles-Messance H, El Mathari B, Sene A, Barbe P, Fouquet S, Aragón J, Darche M, Giocanti-Aurégan A, Paques M, Sahel JA, Tadayoni R, Montañez C, Dalkara D, Rendon A. AAV-mediated gene therapy in Dystrophin-Dp71 deficient mouse leads to blood-retinal barrier restoration and oedema reabsorption. Hum Mol Genet 2016; 25:3070-3079. [PMID: 27288449 DOI: 10.1093/hmg/ddw159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/28/2016] [Accepted: 05/19/2016] [Indexed: 11/12/2022] Open
Abstract
Dystrophin-Dp71 being a key membrane cytoskeletal protein, expressed mainly in Müller cells that provide a mechanical link at the Müller cell membrane by direct binding to actin and a transmembrane protein complex. Its absence has been related to blood-retinal barrier (BRB) permeability through delocalization and down-regulation of the AQP4 and Kir4.1 channels (1). We have previously shown that the adeno-associated virus (AAV) variant, ShH10, transduces Müller cells in the Dp71-null mouse retina efficiently and specifically (2,3). Here, we use ShH10 to restore Dp71 expression in Müller cells of Dp71 deficient mouse to study molecular and functional effects of this restoration in an adult mouse displaying retinal permeability. We show that strong and specific expression of exogenous Dp71 in Müller cells leads to correct localization of Dp71 protein restoring all protein interactions in order to re-establish a proper functional BRB and retina homeostasis thus preventing retina from oedema. This study is the basis for the development of new therapeutic strategies in dealing with diseases with BRB breakdown and macular oedema such as diabetic retinopathy (DR).
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Affiliation(s)
- Ophélie Vacca
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France .,Neuroscience Paris-Saclay Institute (NeuroPSI)-CNRS UMR 9197-Université Paris-Sud, Cognition & Behavior, 91405 Orsay cedex, France
| | - Hugo Charles-Messance
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Brahim El Mathari
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Abdoulaye Sene
- Department of Ophthalmology, Therapeutic, Saint Louis, MO 63103, USA
| | - Peggy Barbe
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Stéphane Fouquet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Jorge Aragón
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France.,Department of Genetics & Molecular Biology, CINVESTAV: Research Centre for Advanced Studies, IPN, C.P. 07360 México
| | - Marie Darche
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Audrey Giocanti-Aurégan
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France.,Ophthalmology Department, Avicenne Hospital, 93000 Bobigny, France
| | - Michel Paques
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC, 75012 Paris, France
| | - José-Alain Sahel
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC, 75012 Paris, France
| | - Ramin Tadayoni
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France.,Ophthalmology Dept, Hôpital Lariboisière, AP-HP, Univ Paris Diderot, 75010 Paris, France
| | - Cecilia Montañez
- Department of Genetics & Molecular Biology, CINVESTAV: Research Centre for Advanced Studies, IPN, C.P. 07360 México
| | - Deniz Dalkara
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Alvaro Rendon
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
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26
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Joly S, Dodd DA, Grewe BF, Pernet V. Reticulon 4A/Nogo-A influences the distribution of Kir4.1 but is not essential for potassium conductance in retinal Müller glia. Neurosci Lett 2016; 627:168-77. [PMID: 27276652 DOI: 10.1016/j.neulet.2016.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/02/2016] [Accepted: 06/04/2016] [Indexed: 11/29/2022]
Abstract
In the adult retina, we have previously shown that Nogo-A was highly expressed in Müller glia. However, the role of Nogo-A in the glial cell physiology is not clear. In this study, we investigated the possible influence that Nogo-A may exert on other polarized molecules in Müller cells, in particular inwardly rectifying potassium channel 4.1 (Kir4.1) and aquaporin 4 (AQP4) that respectively control potassium and water exchange in glial cells. Our results showed that adenovirus-mediated Nogo-A overexpression with AdNogo-A increased the immunofluorescent signal of Kir4.1 in rat Müller cell line 1 (rMC-1) cells but did not change its expression level by Western blotting. In vivo, AdNogo-A induced ectopic Kir4.1 immunoreactivity throughout the radial processes of Müller cells compared with AdLacZ control virus. Surprisingly, AdNogo-A did not modify the distribution of Dp71 and AQP4 that are common binding partners for Kir4.1 in the dystrophin-associated protein (DAP) complex anchored at the plasma membrane of Müller glia. Immunoprecipitation experiments revealed molecular interactions between Nogo-A and Kir4.1. In Nogo-A KO mouse retinae, the distribution of Kir4.1 was not different from that observed in Wild-Type (WT) animals. In addition, potassium conductance did not change in freshly dissociated Nogo-A KO Müller glia compared with WT cells. In summary, the increase of Nogo-A expression can selectively influence the distribution of Kir4.1 in glia but is not essential for Kir4.1-mediated potassium conductance at the plasma membrane in physiological conditions. Nogo-A-Kir4.1 interactions may, however, contribute to pathological processes taking place in the retina, for instance, after ischemia.
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Affiliation(s)
- Sandrine Joly
- CUO-Recherche, Médecine Régénératrice-Centre de recherche FRQS du CHU de Québec-Université Laval, Université Laval, Québec, Canada; Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, QC, Canada; Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Dana A Dodd
- University of Texas Southwestern Medical Center, Department of Microbiology, Dallas, TX, USA
| | | | - Vincent Pernet
- CUO-Recherche, Médecine Régénératrice-Centre de recherche FRQS du CHU de Québec-Université Laval, Université Laval, Québec, Canada; Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, QC, Canada; Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada.
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27
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Nishida A, Yasuno S, Takeuchi A, Awano H, Lee T, Niba ETE, Fujimoto T, Itoh K, Takeshima Y, Nishio H, Matsuo M. HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab. Histochem Cell Biol 2016; 146:301-9. [PMID: 27109495 DOI: 10.1007/s00418-016-1439-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.
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Affiliation(s)
- Atsushi Nishida
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Sato Yasuno
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.,Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Atsuko Takeuchi
- Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Tomoko Lee
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Emma Tabe Eko Niba
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Takahiro Fujimoto
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Kyoko Itoh
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Hisahide Nishio
- Department of Community Medicine and Social Healthcare Science, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Masafumi Matsuo
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.
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28
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Giocanti-Auregan A, Vacca O, Bénard R, Cao S, Siqueiros L, Montañez C, Paques M, Sahel JA, Sennlaub F, Guillonneau X, Rendon A, Tadayoni R. Altered astrocyte morphology and vascular development in dystrophin-Dp71-null mice. Glia 2015; 64:716-29. [PMID: 26711882 DOI: 10.1002/glia.22956] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/28/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023]
Abstract
Understanding retinal vascular development is crucial because many retinal vascular diseases such as diabetic retinopathy (in adults) or retinopathy of prematurity (in children) are among the leading causes of blindness. Given the localization of the protein Dp71 around the retinal vessels in adult mice and its role in maintaining retinal homeostasis, the aim of this study was to determine if Dp71 was involved in astrocyte and vascular development regulation. An experimental study in mouse retinas was conducted. Using a dual immunolabeling with antibodies to Dp71 and anti-GFAP for astrocytes on retinal sections and isolated astrocytes, it was found that Dp71 was expressed in wild-type (WT) mouse astrocytes from early developmental stages to adult stage. In Dp71-null mice, a reduction in GFAP-immunopositive astrocytes was observed as early as postnatal day 6 (P6) compared with WT mice. Using real-time PCR, it was showed that Dp71 mRNA was stable between P1 and P6, in parallel with post-natal vascular development. Regarding morphology in Dp71-null and WT mice, a significant decrease in overall astrocyte process number in Dp71-null retinas at P6 to adult age was found. Using fluorescence-conjugated isolectin Griffonia simplicifolia on whole mount retinas, subsequent delay of developing vascular network at the same age in Dp71-null mice was found. An evidence that the Dystrophin Dp71, a membrane-associated cytoskeletal protein and one of the smaller Duchenne muscular dystrophy gene products, regulates astrocyte morphology and density and is associated with subsequent normal blood vessel development was provided.
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Affiliation(s)
- Audrey Giocanti-Auregan
- Ophthalmology Department, Avicenne Hospital, 125 Rue De Stalingrad, Bobigny, France.,Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Ophélie Vacca
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Romain Bénard
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Sijia Cao
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Lourdes Siqueiros
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Cecilia Montañez
- Department of Genetics & Molecular Biology, Research Centre for Advanced Studies, IPN, Av. I.P.N. 2508, Mexico City, C.P., 07360, Mexico
| | - Michel Paques
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National D'ophtalmologie Des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - José-Alain Sahel
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National D'ophtalmologie Des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris, F-75012, France.,Fondation Ophtalmologique Rothschild, Paris, F-75019, France
| | - Florian Sennlaub
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Xavier Guillonneau
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Alvaro Rendon
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Ramin Tadayoni
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Ophthalmology Department, Hôpital Lariboisière, AP-HP, University Paris 7, Sorbonne Paris Cité, 2 Rue Ambroise Paré, Paris, 75010, France
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29
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Aragón J, Martínez-Herrera A, Romo-Yáñez J, Ceja V, Azotla-Vilchis C, Siqueiros-Márquez L, Soid-Raggi G, Herrera-Salazar A, Montañez C. Identification of Dp71 Isoforms Expressed in PC12 Cells: Subcellular Localization and Colocalization with β-Dystroglycan and α1-Syntrophin. J Mol Neurosci 2015; 58:201-9. [DOI: 10.1007/s12031-015-0657-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 09/14/2015] [Indexed: 11/24/2022]
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30
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Activity-Dependent Plasticity of Astroglial Potassium and Glutamate Clearance. Neural Plast 2015; 2015:109106. [PMID: 26346563 PMCID: PMC4539499 DOI: 10.1155/2015/109106] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/17/2015] [Indexed: 12/21/2022] Open
Abstract
Recent evidence has shown that astrocytes play essential roles in synaptic transmission and plasticity. Nevertheless, how neuronal activity alters astroglial functional properties and whether such properties also display specific forms of plasticity still remain elusive. Here, we review research findings supporting this aspect of astrocytes, focusing on their roles in the clearance of extracellular potassium and glutamate, two neuroactive substances promptly released during excitatory synaptic transmission. Their subsequent removal, which is primarily carried out by glial potassium channels and glutamate transporters, is essential for proper functioning of the brain. Similar to neurons, different forms of short- and long-term plasticity in astroglial uptake have been reported. In addition, we also present novel findings showing robust potentiation of astrocytic inward currents in response to repetitive stimulations at mild frequencies, as low as 0.75 Hz, in acute hippocampal slices. Interestingly, neurotransmission was hardly affected at this frequency range, suggesting that astrocytes may be more sensitive to low frequency stimulation and may exhibit stronger plasticity than neurons to prevent hyperexcitability. Taken together, these important findings strongly indicate that astrocytes display both short- and long-term plasticity in their clearance of excess neuroactive substances from the extracellular space, thereby regulating neuronal activity and brain homeostasis.
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31
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Nichols B, Takeda S, Yokota T. Nonmechanical Roles of Dystrophin and Associated Proteins in Exercise, Neuromuscular Junctions, and Brains. Brain Sci 2015; 5:275-98. [PMID: 26230713 PMCID: PMC4588140 DOI: 10.3390/brainsci5030275] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/29/2015] [Accepted: 07/21/2015] [Indexed: 02/06/2023] Open
Abstract
Dystrophin-glycoprotein complex (DGC) is an important structural unit in skeletal muscle that connects the cytoskeleton (f-actin) of a muscle fiber to the extracellular matrix (ECM). Several muscular dystrophies, such as Duchenne muscular dystrophy, Becker muscular dystrophy, congenital muscular dystrophies (dystroglycanopathies), and limb-girdle muscular dystrophies (sarcoglycanopathies), are caused by mutations in the different DGC components. Although many early studies indicated DGC plays a crucial mechanical role in maintaining the structural integrity of skeletal muscle, recent studies identified novel roles of DGC. Beyond a mechanical role, these DGC members play important signaling roles and act as a scaffold for various signaling pathways. For example, neuronal nitric oxide synthase (nNOS), which is localized at the muscle membrane by DGC members (dystrophin and syntrophins), plays an important role in the regulation of the blood flow during exercise. DGC also plays important roles at the neuromuscular junction (NMJ) and in the brain. In this review, we will focus on recently identified roles of DGC particularly in exercise and the brain.
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Affiliation(s)
- Bailey Nichols
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
- Muscular Dystrophy Canada Research Chair, 8812-112 St, Edmonton, AB T6G 2H7, Canada.
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32
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El Mathari B, Sene A, Charles-Messance H, Vacca O, Guillonneau X, Grepin C, Sennlaub F, Sahel JA, Rendon A, Tadayoni R. Dystrophin Dp71 gene deletion induces retinal vascular inflammation and capillary degeneration. Hum Mol Genet 2015; 24:3939-47. [PMID: 25901007 DOI: 10.1093/hmg/ddv132] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 04/09/2015] [Indexed: 12/17/2022] Open
Abstract
We have previously shown that the deletion of the dystrophin Dp71 gene induces a highly permeable blood-retinal barrier (BRB). Given that BRB breakdown is involved in retinal inflammation and the pathophysiology of many blinding eye diseases, here we investigated whether the absence of Dp71 brings out retinal vascular inflammation and vessel loss by using specific Dp71-null mice. The expression of vascular endothelial growth factor (VEGF), quantified by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay methods, was higher in the retina of Dp71-null mice than in wild-type mice. In contrast, no differences were observed in VEGFR-2 and tumor necrosis factor-α expression. Moreover, mRNA expression of water channel, aquaporin 4 (AQP4) was increased after Dp71 deletion. The Dp71 deletion was also associated with the overexpression of intercellular adhesion molecule 1, which is expressed on endothelial cells surface to recruit leukocytes. Consistent with these findings, the total number of adherent leukocytes per retina, assessed after perfusion with fluorescein isothiocyanate-conjugated concanavalin A, was increased in the absence of Dp71. Finally, a significant increase in capillary degeneration quantified after retinal trypsin digestion was observed in mice lacking Dp71. These data illustrate for the first time that the deletion of Dp71 was associated with retinal vascular inflammation, vascular lesions with increased leukocyte adhesion and capillary degeneration. Thus, dystrophin Dp71 could play a critical role in retinal vascular inflammation disease, and therefore represent a potential therapeutic target.
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Affiliation(s)
- Brahim El Mathari
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France, Sanofi Fovea-Ophthalmology, Paris, France
| | - Abdoulaye Sene
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO, USA
| | - Hugo Charles-Messance
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
| | - Ophélie Vacca
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
| | - Xavier Guillonneau
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
| | | | - Florian Sennlaub
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
| | - José-Alain Sahel
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France, Institute of Ophthalmology, University College of London, UK, Académie des Sciences-Institut de France, Paris, France and
| | - Alvaro Rendon
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
| | - Ramin Tadayoni
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France, Ophthalmology Department, Hôpital Lariboisière (AP-HP) 2, Université Paris 7, Sorbonne Paris Cité, rue Ambroise Paré, 75010 Paris, France
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Tan J, Tan S, Zheng H, Liu M, Chen G, Zhang H, Wang K, Tan S, Zhou J, Xiao XZ. HSF1 functions as a transcription regulator for Dp71 expression. Cell Stress Chaperones 2015; 20:371-9. [PMID: 25430510 PMCID: PMC4326382 DOI: 10.1007/s12192-014-0558-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 11/13/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022] Open
Abstract
Heat shock factor 1 (HSF1) is one of the most important transcriptional molecules in the heat shock process; however, HSF1 can also regulate the expression of other proteins. Dystrophin Dp71 is one of the most widely expressed isoforms of the dystrophin gene family. In our experiments, we showed for the first time that HSF1 can function as a transcriptional factor for endogenous Dp71 expression in vivo and in vitro. We demonstrated that the messenger RNA (mRNA) and protein expression of Dp71 were significantly reduced in HSF1-knockout mice compared with wild-type mice in brain, lung, liver, spleen, and kidney. Overexpression of HSF1 significantly enhanced the mRNA and protein expression of Dp71 in HeLa cells. Inhibiting the expression of HSF1 in HeLa cells significantly reduced the expression of Dp71. By use of the EMSA technique, the chromatin immunoprecipitation assay, and the luciferase reporter system, we demonstrated that HSF1 can directly bind the HSE in the Dp71 promoter region. We concluded from our data that HSF1 functions as a transcriptional regulator of Dp71 expression.
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Affiliation(s)
- Jin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sichuang Tan
- />Department of Thoracic and Cardiovascular Surgery, Second Xiangya Hospital, 139# Ren Ming Road, Changsha, Hunan 410011 People’s Republic of China
| | - Hexin Zheng
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning, Institute of Hunan Province, Changsha, 410126 China
| | - Meidong Liu
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Guangwen Chen
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Huali Zhang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Kangkai Wang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sipin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Molecular and Cell Experimental Center, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013 People’s Republic of China
| | - Jiang Zhou
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Xian-zhong Xiao
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
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Gondo A, Shinotsuka T, Morita A, Abe Y, Yasui M, Nuriya M. Sustained down-regulation of β-dystroglycan and associated dysfunctions of astrocytic endfeet in epileptic cerebral cortex. J Biol Chem 2014; 289:30279-30288. [PMID: 25228692 DOI: 10.1074/jbc.m114.588384] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epilepsy is characterized by the abnormal activation of neurons in the cerebral cortex, but the molecular and cellular mechanisms contributing to the development of recurrent seizures are largely unknown. Recently, the critical involvement of astrocytes in the pathophysiology of epilepsy has been proposed. However, the nature of plastic modulations of astrocytic proteins in the epileptic cortex remains poorly understood. In this study, we utilized the zero magnesium in vitro model of epilepsy and examined the potential molecular changes of cortical astrocytes, focusing specifically on endfeet, where specialized biochemical compartments exist. We find that the continuous epileptic activation of neurons for 1 h decreases the expression level of β-dystroglycan (βDG) in acute cortical brain slices prepared from mice. This change is completely abolished by the pharmacological blockade of NMDA-type glutamate receptors as well as by matrix metalloproteinase inhibitors. Consistent with the highly specialized localization of βDG at astrocytic endfeet, where it plays a pivotal role in anchoring endfeet-enriched proteins in astrocytes, the down-regulation of βDG is accompanied by a decrease in the expression of AQP4 but not laminin. Importantly, this down-regulation of βDG persists for at least 1 h, even after the apparent recovery of neuronal activation. Finally, we show that the down-regulation of βDG is associated with the dysfunction of the endfeet at the blood-brain interface as a diffusion barrier. These results suggest that the sustained down-regulation of βDG leads to dysfunctions of astrocytic endfeet in the epileptic cerebral cortex and may contribute to the pathogenesis of epilepsy.
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Affiliation(s)
- Asako Gondo
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan,; Department of Nephrology and Dialysis, Tokyo Medical University, Tokyo 160-0023, Japan, and
| | - Takanori Shinotsuka
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Ayaka Morita
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan,; College of Engineering and Yokohama National University, Kanagawa 240-8501, Japan
| | - Yoichiro Abe
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Masato Yasui
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mutsuo Nuriya
- Department of Pharmacology, Keio University School of Medicine, Tokyo 160-8582, Japan,; Graduate School of Environment and Information Sciences, Yokohama National University, Kanagawa 240-8501, Japan.
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Suárez-Sánchez R, Aguilar A, Wagstaff KM, Velez G, Azuara-Medina PM, Gomez P, Vásquez-Limeta A, Hernández-Hernández O, Lieu KG, Jans DA, Cisneros B. Nucleocytoplasmic shuttling of the Duchenne muscular dystrophy gene product dystrophin Dp71d is dependent on the importin α/β and CRM1 nuclear transporters and microtubule motor dynein. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:985-1001. [PMID: 24486332 DOI: 10.1016/j.bbamcr.2014.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 12/17/2013] [Accepted: 01/24/2014] [Indexed: 01/08/2023]
Abstract
Even though the Duchenne muscular dystrophy (DMD) gene product Dystrophin Dp71d is involved in various key cellular processes through its role as a scaffold for structural and signalling proteins at the plasma membrane as well as the nuclear envelope, its subcellular trafficking is poorly understood. Here we map the nuclear import and export signals of Dp71d by truncation and point mutant analysis, showing for the first time that Dp71d shuttles between the nucleus and cytoplasm mediated by the conventional nuclear transporters, importin (IMP) α/β and the exportin CRM1. Binding was confirmed in cells using pull-downs, while in vitro binding assays showed direct, high affinity (apparent dissociation coefficient of c. 0.25nM) binding of Dp71d to IMPα/β. Interestingly, treatment of cells with the microtubule depolymerizing reagent nocodazole or the dynein inhibitor EHNA both decreased Dp71d nuclear localization, implying that Dp71d nuclear import may be facilitated by microtubules and the motor protein dynein. The role of Dp71d in the nucleus appears to relate in part to interaction with the nuclear envelope protein emerin, and maintenance of the integrity of the nuclear architecture. The clear implication is that Dp71d's previously unrecognised nuclear transport properties likely contribute to various, important physiological roles.
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Affiliation(s)
- R Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico; Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - A Aguilar
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - K M Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - G Velez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P M Azuara-Medina
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P Gomez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - A Vásquez-Limeta
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - O Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - K G Lieu
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - D A Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
| | - B Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico.
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Cia D, Simonutti M, Fort PE, Doly M, Rendon A. Slight Alteration of the Electroretinogram in Mice Lacking Dystrophin Dp71. Ophthalmic Res 2014; 51:196-203. [DOI: 10.1159/000357272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/11/2013] [Indexed: 11/19/2022]
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Vacca O, Darche M, Schaffer DV, Flannery JG, Sahel JA, Rendon A, Dalkara D. AAV-mediated gene delivery in Dp71-null mouse model with compromised barriers. Glia 2013; 62:468-76. [PMID: 24382652 DOI: 10.1002/glia.22617] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 11/21/2013] [Accepted: 11/22/2013] [Indexed: 12/28/2022]
Abstract
Formation and maintenance of the blood-retinal barrier (BRB) is required for proper vision and breaching of this barrier contributes to the pathology in a wide variety of retinal conditions such as retinal detachment and diabetic retinopathy. Dystrophin Dp71 being a key membrane cytoskeletal protein, expressed mainly in Müller cells, its absence has been related to BRB permeability through delocalization and down-regulation of the AQP4 and Kir4.1 channels. Dp71-null mouse is thus an excellent model to approach the study of retinal pathologies showing blood-retinal barrier permeability. We aimed to investigate the participation of Müller cells in the BRB and in the inner limiting membrane of Dp71-null mice compared with wild-type mice in order to understand how these barriers work in this model of permeable BRB. To this aim, we used an Adeno-associated virus (AAV) variant, ShH10-GFP, engineered to target Müller cells specifically. ShH10 coding GFP was introduced by intravitreal injection and Müller cell transduction was studied in Dp71-null mice in comparison to wild-type animals. We show that Müller cell transduction follows a significantly different pattern in Dp71-null mice indicating changes in viral cell-surface receptors as well as differences in the permeability of the inner limiting membrane in this mouse line. However, the compromised BRB of the Dp71-null mice does not lead to virus leakage into the bloodstream when the virus is injected intravitreally - an important consideration for AAV-mediated retinal gene therapy.
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Affiliation(s)
- Ophélie Vacca
- Institut de la Vision/INSERM/UPMC, Univ Paris 06/CNRS/CHNO des Quinze-Vingts, Paris, France
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Ordered disorder of the astrocytic dystrophin-associated protein complex in the norm and pathology. PLoS One 2013; 8:e73476. [PMID: 24014171 PMCID: PMC3754965 DOI: 10.1371/journal.pone.0073476] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
The abundance and potential functional roles of intrinsically disordered regions in aquaporin-4, Kir4.1, a dystrophin isoforms Dp71, α-1 syntrophin, and α-dystrobrevin; i.e., proteins constituting the functional core of the astrocytic dystrophin-associated protein complex (DAPC), are analyzed by a wealth of computational tools. The correlation between protein intrinsic disorder, single nucleotide polymorphisms (SNPs) and protein function is also studied together with the peculiarities of structural and functional conservation of these proteins. Our study revealed that the DAPC members are typical hybrid proteins that contain both ordered and intrinsically disordered regions. Both ordered and disordered regions are important for the stabilization of this complex. Many disordered binding regions of these five proteins are highly conserved among vertebrates. Conserved eukaryotic linear motifs and molecular recognition features found in the disordered regions of five protein constituting DAPC likely enhance protein-protein interactions that are required for the cellular functions of this complex. Curiously, the disorder-based binding regions are rarely affected by SNPs suggesting that these regions are crucial for the biological functions of their corresponding proteins.
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Matteucci A, Gaddini L, Macchia G, Varano M, Petrucci TC, Macioce P, Malchiodi-Albedi F, Ceccarini M. Developmental expression of dysbindin in Muller cells of rat retina. Exp Eye Res 2013; 116:1-8. [PMID: 23954924 DOI: 10.1016/j.exer.2013.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 07/30/2013] [Accepted: 08/06/2013] [Indexed: 01/09/2023]
Abstract
Dysbindin, the product of the DTNBP1 gene, was identified by yeast two hybrid assay as a binding partner of dystrobrevin, a cytosolic component of the dystrophin protein complex. Although its functional role has not yet been completely elucidated, the finding that dysbindin assembles into the biogenesis of lysosome related organelles complex 1 (BLOC-1) suggests that it participates in intracellular trafficking and biogenesis of organelles and vesicles. Dysbindin is ubiquitous and in brain is expressed primarily in neurons. Variations at the dysbindin gene have been associated with increased risk for schizophrenia. As anomalies in retinal function have been reported in patients suffering from neuropsychiatric disorders, we investigated the expression of dysbindin in the retina. Our results show that differentially regulated dysbindin isoforms are expressed in rat retina during postnatal maturation. Interestingly, we found that dysbindin is mainly localized in Müller cells. The identification of dysbindin in glial cells may open new perspectives for a better understanding of the functional involvement of this protein in visual alterations associated to neuropsychiatric disorders.
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Affiliation(s)
- Andrea Matteucci
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
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Chai RC, Jiang JH, Wong AYK, Jiang F, Gao K, Vatcher G, Hoi Yu AC. AQP5 is differentially regulated in astrocytes during metabolic and traumatic injuries. Glia 2013; 61:1748-65. [PMID: 23922257 DOI: 10.1002/glia.22555] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/30/2013] [Accepted: 06/17/2013] [Indexed: 01/14/2023]
Abstract
Water movement plays vital roles in both physiological and pathological conditions in the brain. Astrocytes are responsible for regulating this water movement and are the major contributors to brain edema in pathological conditions. Aquaporins (AQPs) in astrocytes play critical roles in the regulation of water movement in the brain. AQP1, 3, 4, 5, 8, and 9 have been reported in the brain. Compared with AQP1, 4, and 9, AQP3, 5, and 8 are less studied. Among the lesser known AQPs, AQP5, which has multiple functions identified outside the central nervous system, is also indicated to be involved in hypoxia injury in astrocytes. In our study, AQP5 expression could be detected both in primary cultures of astrocytes and neurons, and AQP5 expression in astrocytes was confirmed in 1- to 4-week old primary cultures of astrocytes. AQP5 was localized on the cytoplasmic membrane and in the cytoplasm of astrocytes. AQP5 expression was downregulated during ischemia treatment and upregulated after scratch-wound injury, which was also confirmed in a middle cerebral artery occlusion model and a stab-wound injury model in vivo. The AQP5 increased after scratch injury was polarized to the migrating processes and cytoplasmic membrane of astrocytes in the leading edge of the scratch-wound, and AQP5 over-expression facilitated astrocyte process elongation after scratch injury. Taken together, these results indicate that AQP5 might be an important water channel in astrocytes that is differentially expressed during various brain injuries.
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Affiliation(s)
- Rui Chao Chai
- Neuroscience Research Institute & Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
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Effects of prednisolone on the dystrophin-associated proteins in the blood-brain barrier and skeletal muscle of dystrophic mdx mice. J Transl Med 2013; 93:592-610. [PMID: 23528847 DOI: 10.1038/labinvest.2013.46] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mdx mouse, the most widely used animal model of Duchenne muscular dystrophy (DMD), develops a seriously impaired blood-brain barrier (BBB). As glucocorticoids are used clinically to delay the progression of DMD, we evaluated the effects of chronic treatment with α-methyl-prednisolone (PDN) on the expression of structural proteins and markers in the brain and skeletal muscle of the mdx mouse. We analyzed the immunocytochemical and biochemical expression of four BBB markers, including endothelial ZO-1 and occludin, desmin in pericytes, and glial fibrillary acidic protein (GFAP) in glial cells, and the expression of the short dystrophin isoform Dp 71, the dystrophin-associated proteins (DAPs), and aquaporin-4 (AQP4) and α-β dystroglycan (DG) in the brain. We evaluated the BBB integrity of mdx and PDN-treated mdx mice by means of intravascular injection of horseradish peroxidase (HRP). The expression of DAPs was also assessed in gastrocnemius muscles and correlated with utrophin expression, and laminin content was measured in the muscle and brain. PDN treatment induced a significant increase in the mRNA and protein content of the BBB markers; a reduction in the phosphorylation of occludin in the brain and of AQP4/β DG in both tissues; an increase of Dp71 protein content; and an increase of both mRNA and protein levels of the AQP4/α-β DG complex. The latter was associated with enhanced laminin and utrophin in the muscle. The HRP assay demonstrated functional restoration of the BBB in the PDN-treated mdx mice. Specifically, mdx mice showed extensive perivascular labeling due to escape of the marker, while HRP was exclusively intravascular in the PDN-treated mice and the controls. These data illustrate for the first time that PDN reverses the BBB alterations in the mdx mouse and re-establishes the proper expression and phosphorylation of β-DG in both the BBB and skeletal muscle. Further, PDN partially protects against muscle damage. The reduction in AQP4 and occludin phosphorylation, coupled with their anchoring to glial and endothelial membranes in PDN-treated mice, suggests that the drug may target the glial and endothelial cells. Our results suggest a novel mechanism for PDN action on cerebral and muscular function, restoring the link between DAPs and the extracellular matrix, most likely through protein kinase inactivation.
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Enger R, Gundersen GA, Haj-Yasein NN, Eilert-Olsen M, Thoren AE, Vindedal GF, Petersen PH, Skare Ø, Nedergaard M, Ottersen OP, Nagelhus EA. Molecular scaffolds underpinning macroglial polarization: an analysis of retinal Müller cells and brain astrocytes in mouse. Glia 2012; 60:2018-26. [PMID: 22987438 DOI: 10.1002/glia.22416] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/15/2012] [Indexed: 11/11/2022]
Abstract
Key roles of macroglia are inextricably coupled to specialized membrane domains. The perivascular endfoot membrane has drawn particular attention, as this domain contains a unique complement of aquaporin-4 (AQP4) and other channel proteins that distinguishes it from perisynaptic membranes. Recent studies indicate that the polarization of macroglia is lost in a number of diseases, including temporal lobe epilepsy and Alzheimer's disease. A better understanding is required of the molecular underpinning of astroglial polarization, particularly when it comes to the significance of the dystrophin associated protein complex (DAPC). Here, we employ immunofluorescence and immunogold cytochemistry to analyze the molecular scaffolding in perivascular endfeet in macroglia of retina and three regions of brain (cortex, dentate gyrus, and cerebellum), using AQP4 as a marker. Compared with brain astrocytes, Müller cells (a class of retinal macroglia) exhibit lower densities of the scaffold proteins dystrophin and α-syntrophin (a DAPC protein), but higher levels of AQP4. In agreement, depletion of dystrophin or α-syntrophin--while causing a dramatic loss of AQP4 from endfoot membranes of brain astrocytes--had only modest or insignificant effect, respectively, on the AQP4 pool in endfoot membranes of Müller cells. In addition, while polarization of brain macroglia was less affected by dystrophin depletion than by targeted deletion of α-syntrophin, the reverse was true for retinal macroglia. These data indicate that the molecular scaffolding in perivascular endfeet is more complex than previously assumed and that macroglia are heterogeneous with respect to the mechanisms that dictate their polarization.
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Affiliation(s)
- Rune Enger
- Centre for Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo, Norway
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Beyond Polarity: Functional Membrane Domains in Astrocytes and Müller Cells. Neurochem Res 2012; 37:2513-23. [DOI: 10.1007/s11064-012-0824-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 06/01/2012] [Accepted: 06/08/2012] [Indexed: 10/28/2022]
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Song Y, Gunnarson E. Potassium dependent regulation of astrocyte water permeability is mediated by cAMP signaling. PLoS One 2012; 7:e34936. [PMID: 22493723 PMCID: PMC3321040 DOI: 10.1371/journal.pone.0034936] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/11/2012] [Indexed: 11/18/2022] Open
Abstract
Astrocytes express potassium and water channels to support dynamic regulation of potassium homeostasis. Potassium kinetics can be modulated by aquaporin-4 (AQP4), the essential water channel for astrocyte water permeability regulation. We investigated whether extracellular potassium ([K(+)](o)) can regulate astrocyte water permeability and the mechanisms of such an effect. Studies were performed on rat primary astrocytes and a rat astrocyte cell line transfected with AQP4. We found that 10 mM [K(+)](o) caused an immediate, more than 40%, increase in astrocyte water permeability which was sustained in 5 min. The water channel AQP4 was a target for this regulation. Potassium induced a significant increase in intracellular cAMP as measured with a FRET based method and with enzyme immunoassay. We found that protein kinase A (PKA) could phosphorylate AQP4 in vitro. Further elevation of [K(+)](o) to 35 mM induced a global intracellular calcium response and a transient water permeability increase that was abolished in 5 min. When inwardly rectifying potassium (Kir)-channels were blocked, 10 mM [K(+)](o) also induced a calcium increase and the water permeability increase no longer persisted. In conclusion, we find that elevation of extracellular potassium regulates AQP4 and astrocyte water permeability via intracellular signaling involving cAMP. A prolonged increase of astrocyte water permeability is Kir-channel dependent and this response can be impeded by intracellular calcium signaling. Our results support the concept of coupling between AQP4 and potassium handling in astrocytes.
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Affiliation(s)
- Yutong Song
- Department of Women’s and Children’s Health, Karolinska Institutet, Astrid Lindgren Children’s Hospital, Stockholm, Sweden
| | - Eli Gunnarson
- Department of Women’s and Children’s Health, Karolinska Institutet, Astrid Lindgren Children’s Hospital, Stockholm, Sweden
- * E-mail:
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Perronnet C, Chagneau C, Le Blanc P, Samson-Desvignes N, Mornet D, Laroche S, De La Porte S, Vaillend C. Upregulation of brain utrophin does not rescue behavioral alterations in dystrophin-deficient mice. Hum Mol Genet 2012; 21:2263-76. [PMID: 22343141 DOI: 10.1093/hmg/dds047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dystrophin, the protein responsible for X-linked Duchenne muscular dystrophy (DMD), is normally expressed in both muscle and brain, which explains that its loss also leads to cognitive deficits. The utrophin protein, an autosomal homolog, is a natural candidate for dystrophin replacement in patients. Pharmacological upregulation of endogenous utrophin improves muscle physiology in dystrophin-deficient mdx mice, and represents a potential therapeutic tool that has the advantage of allowing delivery to various organs following peripheral injections. Whether this could alleviate cognitive deficits, however, has not been explored. Here, we first investigated basal expression of all utrophins and dystrophins in the brain of mdx mice and found no evidence for spontaneous compensation by utrophins. Then, we show that systemic chronic, spaced injections of arginine butyrate (AB) alleviate muscle alterations and upregulate utrophin expression in the adult brain of mdx mice. AB selectively upregulated brain utrophin Up395, while reducing expression of Up113 and Up71. This, however, was not associated with a significant improvement of behavioral functions typically affected in mdx mice, which include exploration, emotional reactivity, spatial and fear memories. We suggest that AB did not overcome behavioral and cognitive dysfunctions because the regional and cellular expression of utrophins did not coincide with dystrophin expression in untreated mice, nor did it in AB-treated mice. While treatments based on the modulation of utrophin may alleviate DMD phenotypes in certain organs and tissues that coexpress dystrophins and utrophins in the same cells, improvement of cognitive functions would likely require acting on specific dystrophin-dependent mechanisms.
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Affiliation(s)
- Caroline Perronnet
- Univ Paris-Sud, Centre de Neurosciences Paris-Sud, UMR8195, Orsay F-91405, France
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Eilert-Olsen M, Haj-Yasein NN, Vindedal GF, Enger R, Gundersen GA, Hoddevik EH, Petersen PH, Haug FMS, Skare Ø, Adams ME, Froehner SC, Burkhardt JM, Thoren AE, Nagelhus EA. Deletion of aquaporin-4 changes the perivascular glial protein scaffold without disrupting the brain endothelial barrier. Glia 2011; 60:432-40. [PMID: 22131281 DOI: 10.1002/glia.22277] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 11/11/2011] [Indexed: 11/08/2022]
Abstract
Expression of the water channel aquaporin-4 (AQP4) at the blood-brain interface is dependent upon the dystrophin associated protein complex. Here we investigated whether deletion of the Aqp4 gene affects the molecular composition of this protein scaffold and the integrity of the blood-brain barrier. High-resolution immunogold cytochemistry revealed that perivascular expression of α-syntrophin was reduced by 60% in Aqp4(-/-) mice. Additionally, perivascular AQP4 expression was reduced by 88% in α-syn(-/-) mice, in accordance with earlier reports. Immunofluorescence showed that Aqp4 deletion also caused a modest reduction in perivascular dystrophin, whereas β-dystroglycan labeling was unaltered. Perivascular microglia were devoid of AQP4 immunoreactivity. Deletion of Aqp4 did not alter the ultrastructure of capillary endothelial cells, the expression of tight junction proteins (claudin-5, occludin, and zonula occludens 1), or the vascular permeability to horseradish peroxidase and Evans blue albumin dye. We conclude that Aqp4 deletion reduces the expression of perivascular glial scaffolding proteins without affecting the endothelial barrier. Our data also indicate that AQP4 and α-syntrophin are mutually dependent upon each other for proper perivascular expression.
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Affiliation(s)
- Martine Eilert-Olsen
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo, 0318 Oslo, Norway
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Dystrophin Dp71: The Smallest but Multifunctional Product of the Duchenne Muscular Dystrophy Gene. Mol Neurobiol 2011; 45:43-60. [DOI: 10.1007/s12035-011-8218-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
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49
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Aragón J, Romo-Yáñez J, Martínez-Herrera A, Ceja V, Rendon A, Montañez C. Characterization of Dp71Δ(78-79), a novel dystrophin mutant that stimulates PC12 cell differentiation. J Neurochem 2011; 119:697-707. [PMID: 21668890 DOI: 10.1111/j.1471-4159.2011.07347.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dp71 has an important role in the central nervous system. To better understand the function of Dp71 domains in neuronal differentiation, PC12 cells were stably transfected with a dystrophin mutant, Dp71Δ(78-79) , which lacks exons 78 and 79. Based on the percentage of cells bearing neurites and neurite length analyses, we found that cells stably expressing Dp71Δ(78-79) (PC12-C11) differentiate more efficiently than non-transfected cells. While wild-type cells reach their maximum differentiation 9-12 days after initiating the differentiation process, the PC12-C11 cells reach differentiation in 4-6 days. Protein expression analysis showed a down-regulation of Dp71a and an up-regulation of Dp71ab and/or Up71, β-dystroglycan and neuron-specific enolase in undifferentiated and in neural growth factor differentiated PC12-C11 cells. No change was observed in the expression of Grb2 and Up400. The subcellular localization of Dp71Δ(78-79) was in the cell periphery, and there was no change in localization during the differentiation process, which was also observed throughout the neurite extensions.
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Affiliation(s)
- Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, DF, México
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Expression of Dystrophins and the Dystrophin-Associated-Protein Complex by Pituicytes in Culture. Neurochem Res 2011; 36:1407-16. [DOI: 10.1007/s11064-011-0466-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 11/30/2022]
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