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Yang J, Cao C, Liu J, Liu Y, Lu J, Yu H, Li X, Wu J, Yu Z, Li H, Chen G. Dystrophin 71 deficiency causes impaired aquaporin-4 polarization contributing to glymphatic dysfunction and brain edema in cerebral ischemia. Neurobiol Dis 2024; 199:106586. [PMID: 38950712 DOI: 10.1016/j.nbd.2024.106586] [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: 03/27/2024] [Revised: 06/28/2024] [Accepted: 06/28/2024] [Indexed: 07/03/2024] Open
Abstract
OBJECTIVE The glymphatic system serves as a perivascular pathway that aids in clearing liquid and solute waste from the brain, thereby enhancing neurological function. Disorders in glymphatic drainage contribute to the development of vasogenic edema following cerebral ischemia, although the molecular mechanisms involved remain poorly understood. This study aims to determine whether a deficiency in dystrophin 71 (DP71) leads to aquaporin-4 (AQP4) depolarization, contributing to glymphatic dysfunction in cerebral ischemia and resulting in brain edema. METHODS A mice model of middle cerebral artery occlusion and reperfusion was used. A fluorescence tracer was injected into the cortex and evaluated glymphatic clearance. To investigate the role of DP71 in maintaining AQP4 polarization, an adeno-associated virus with the astrocyte promoter was used to overexpress Dp71. The expression and distribution of DP71 and AQP4 were analyzed using immunoblotting, immunofluorescence, and co-immunoprecipitation techniques. The behavior ability of mice was evaluated by open field test. Open-access transcriptome sequencing data were used to analyze the functional changes of astrocytes after cerebral ischemia. MG132 was used to inhibit the ubiquitin-proteasome system. The ubiquitination of DP71 was detected by immunoblotting and co-immunoprecipitation. RESULTS During the vasogenic edema stage following cerebral ischemia, a decline in the efflux of interstitial fluid tracer was observed. DP71 and AQP4 were co-localized and interacted with each other in the perivascular astrocyte endfeet. After cerebral ischemia, there was a notable reduction in DP71 protein expression, accompanied by AQP4 depolarization and proliferation of reactive astrocytes. Increased DP71 expression restored glymphatic drainage and reduced brain edema. AQP4 depolarization, reactive astrocyte proliferation, and the behavior of mice were improved. After cerebral ischemia, DP71 was degraded by ubiquitination, and MG132 inhibited the decrease of DP71 protein level. CONCLUSION AQP4 depolarization after cerebral ischemia leads to glymphatic clearance disorder and aggravates cerebral edema. DP71 plays a pivotal role in regulating AQP4 polarization and consequently influences glymphatic function. Changes in DP71 expression are associated with the ubiquitin-proteasome system. This study offers a novel perspective on the pathogenesis of brain edema following cerebral ischemia.
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Affiliation(s)
- Jian Yang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - Chang Cao
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - Jiale Liu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - Yangyang Liu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - Jinxin Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - HaoYun Yu
- Suzhou Medical College, Soochow University, Suzhou, Jiangsu Province, China
| | - Xiang Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
| | - Jiang Wu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China.
| | - Zhengquan Yu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China.
| | - Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China.
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China; Institute of Stroke Research, Soochow University, Suzhou, Jiangsu Province, China
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Arreguin AJ, Shao Z, Colognato H. Dmd mdx mice have defective oligodendrogenesis, delayed myelin compaction and persistent hypomyelination. Dis Model Mech 2024; 17:dmm050115. [PMID: 38721692 PMCID: PMC11095635 DOI: 10.1242/dmm.050115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 03/28/2024] [Indexed: 05/18/2024] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, resulting in the loss of dystrophin, a large cytosolic protein that links the cytoskeleton to extracellular matrix receptors in skeletal muscle. Aside from progressive muscle damage, many patients with DMD also have neurological deficits of unknown etiology. To investigate potential mechanisms for DMD neurological deficits, we assessed postnatal oligodendrogenesis and myelination in the Dmdmdx mouse model. In the ventricular-subventricular zone (V-SVZ) stem cell niche, we found that oligodendrocyte progenitor cell (OPC) production was deficient, with reduced OPC densities and proliferation, despite a normal stem cell niche organization. In the Dmdmdx corpus callosum, a large white matter tract adjacent to the V-SVZ, we also observed reduced OPC proliferation and fewer oligodendrocytes. Transmission electron microscopy further revealed significantly thinner myelin, an increased number of abnormal myelin structures and delayed myelin compaction, with hypomyelination persisting into adulthood. Our findings reveal alterations in oligodendrocyte development and myelination that support the hypothesis that changes in diffusion tensor imaging seen in patients with DMD reflect developmental changes in myelin architecture.
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Affiliation(s)
- Andrea J. Arreguin
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
- Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794-8651, USA
| | - Zijian Shao
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Holly Colognato
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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Nirwane A, Kang M, Adithan A, Maharaj V, Nguyen F, Santaella Aguilar E, Nasrollahi A, Yao Y. Endothelial and mural laminin-α5 contributes to neurovascular integrity maintenance. Fluids Barriers CNS 2024; 21:18. [PMID: 38383451 PMCID: PMC10882802 DOI: 10.1186/s12987-024-00521-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 02/08/2024] [Indexed: 02/23/2024] Open
Abstract
BACKGROUND Laminin-α5, a major component of the basal lamina, is predominantly synthesized by endothelial and mural cells (pericytes and vascular smooth muscle cells) in the CNS. Loss of laminin-α5 in either population fails to induce any abnormalities due to functional redundancy. Thus, the functional significance of laminin-α5 in neurovascular integrity remains unknown. Here, we hypothesize that ablation of laminin-α5 in both endothelial and mural cells increases neurovascular permeability. METHODS The compound knockout mice were generated by crossing laminin-α5 floxed mice with Tie2-Cre and PDGFRβ-Cre, which target endothelial cells and mural cells, respectively. Neurovascular permeability in these mutants was determined with both exogenous and endogenous tracers. Endothelial paracellular and transcellular permeability was assessed by examining the expression of tight junction proteins and transcytosis-associated proteins. In addition, transmission electron microscopy (TEM) was used to visualize tight junction ultrastructure and endothelial caveolae vesicles. Defects in pericytes and astrocytes were investigated by examining pericyte coverage/contact and astrocyte polarity. RESULTS Elevated neurovascular permeability was observed in the mutants. Subsequent studies found increased Caveolin-1 and decreased major facilitator superfamily domain-containing protein 2a (MFSD2A) expression, but unaltered Claudin-5 or zonula occludens-1 (ZO-1) expression. Consistent with these results, mutant mice exhibited increased endothelial caveolae vesicle number with intact tight junction structure under TEM. Additionally, pericyte coverage and contact were also decreased in the mutant mice, while astrocyte polarity was unaffected. CONCLUSIONS These results strongly indicate that endothelial and mural cell-derived laminin-α5 actively maintains neurovascular integrity via the transcellular rather than paracellular mechanism.
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Affiliation(s)
- Abhijit Nirwane
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Minkyung Kang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Aravinthan Adithan
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Vrishni Maharaj
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Felicia Nguyen
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Elliot Santaella Aguilar
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Ava Nasrollahi
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, 33612, Tampa, FL, USA.
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Mueller SM, McFarland White K, Fass SB, Chen S, Shi Z, Ge X, Engelbach JA, Gaines SH, Bice AR, Vasek MJ, Garbow JR, Culver JP, Martinez-Lozada Z, Cohen-Salmon M, Dougherty JD, Sapkota D. Evaluation of gliovascular functions of AQP4 readthrough isoforms. Front Cell Neurosci 2023; 17:1272391. [PMID: 38077948 PMCID: PMC10701521 DOI: 10.3389/fncel.2023.1272391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/06/2023] [Indexed: 12/20/2023] Open
Abstract
Aquaporin-4 (AQP4) is a water channel protein that links the astrocytic endfeet to the blood-brain barrier (BBB) and regulates water and potassium homeostasis in the brain, as well as the glymphatic clearance of waste products that would otherwise potentiate neurological diseases. Recently, translational readthrough was shown to generate a C-terminally extended variant of AQP4, known as AQP4x, which preferentially localizes around the BBB through interaction with the scaffolding protein α-syntrophin, and loss of AQP4x disrupts waste clearance from the brain. To investigate the function of AQP4x, we generated a novel AQP4 mouse line (AllX) to increase relative levels of the readthrough variant above the ~15% of AQP4 in the brain of wild-type (WT) mice. We validated the line and assessed characteristics that are affected by the presence of AQP4x, including AQP4 and α-syntrophin localization, integrity of the BBB, and neurovascular coupling. We compared AllXHom and AllXHet mice to WT and to previously characterized AQP4 NoXHet and NoXHom mice, which cannot produce AQP4x. An increased dose of AQP4x enhanced perivascular localization of α-syntrophin and AQP4, while total protein expression of the two was unchanged. However, at 100% readthrough, AQP4x localization and the formation of higher order complexes were disrupted. Electron microscopy showed that overall blood vessel morphology was unchanged except for an increased proportion of endothelial cells with budding vesicles in NoXHom mice, which may correspond to a leakier BBB or altered efflux that was identified in NoX mice using MRI. These data demonstrate that AQP4x plays a small but measurable role in maintaining BBB integrity as well as recruiting structural and functional support proteins to the blood vessel. This also establishes a new set of genetic tools for quantitatively modulating AQP4x levels.
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Affiliation(s)
- Shayna M. Mueller
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
| | - Kelli McFarland White
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
| | - Stuart B. Fass
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
| | - Siyu Chen
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
| | - Zhan Shi
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Xia Ge
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO, United States
| | - John A. Engelbach
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO, United States
| | - Seana H. Gaines
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
| | - Annie R. Bice
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
| | - Michael J. Vasek
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
| | - Joel R. Garbow
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO, United States
| | - Joseph P. Culver
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Physics, Washington University in St. Louis, Saint Louis, MO, United States
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, United States
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO, United States
- Imaging Science PhD Program, Washington University in St. Louis, Saint Louis, MO, United States
| | - Zila Martinez-Lozada
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Martine Cohen-Salmon
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, The National Centre for Scientific Research (CNRS), National Institute of Health and Medical Research (INSERM), Université PSL, Paris, France
| | - Joseph D. Dougherty
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, United States
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO, United States
| | - Darshan Sapkota
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, United States
- Department of Neuroscience, University of Texas at Dallas, Richardson, TX, United States
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5
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Mueller SM, White KM, Fass SB, Chen S, Shi Z, Ge X, Engelbach JA, Gaines SH, Bice AR, Vasek MJ, Garbow JR, Culver JP, Zila Martinez-Lozada, Cohen-Salmon M, Dougherty JD, Sapkota D. Evaluation of gliovascular functions of Aqp4 readthrough isoforms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.21.549379. [PMID: 37546949 PMCID: PMC10401933 DOI: 10.1101/2023.07.21.549379] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Aquaporin-4 (AQP4) is a water channel protein that links astrocytic endfeet to the blood-brain barrier (BBB) and regulates water and potassium homeostasis in the brain, as well as the glymphatic clearance of waste products that would otherwise potentiate neurological diseases. Recently, translational readthrough was shown to generate a C-terminally extended variant of AQP4, known as AQP4x, that preferentially localizes around the BBB through interaction with the scaffolding protein α-syntrophin, and loss of AQP4x disrupts waste clearance from the brain. To investigate the function of AQP4x, we generated a novel mouse AQP4 line (AllX) to increase relative levels of the readthrough variant above the ~15% of AQP4 in the brain of wildtype (WT) mice. We validated the line and assessed characteristics that are affected by the presence of AQP4x, including AQP4 and α-syntrophin localization, integrity of the BBB, and neurovascular coupling. We compared AllXHom and AllXHet mice to wildtype, and to previously characterized AQP4 NoXHet and NoXHom mice, which cannot produce AQP4x. Increased dose of AQP4x enhanced perivascular localization of α-syntrophin and AQP4, while total protein expression of the two were unchanged. However, at 100% readthrough, AQP4x localization and formation of higher-order complexes was disrupted. Electron microscopy showed that overall blood vessel morphology was unchanged except for increased endothelial cell vesicles in NoXHom mice, which may correspond to a leakier BBB or altered efflux that was identified in NoX mice using MRI. These data demonstrate that AQP4x plays a small but measurable role in maintaining BBB integrity as well as recruiting structural and functional support proteins to the blood vessel. This also establishes a new set of genetic tools for quantitatively modulating AQP4x levels.
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Affiliation(s)
- Shayna M. Mueller
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Kelli McFarland White
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Stuart B. Fass
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Siyu Chen
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Zhan Shi
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - Xia Ge
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Intellectual and Development Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - John A. Engelbach
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Intellectual and Development Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Seana H Gaines
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Annie R Bice
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Michael J. Vasek
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Joel R. Garbow
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Intellectual and Development Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Joseph P. Culver
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Physics, Washington University in St. Louis, Saint Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO 63110, USA
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Imaging Science PhD Program, Washington University in St. Louis, Saint Louis, MO 63110, USA
| | - Zila Martinez-Lozada
- Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Martine Cohen-Salmon
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Joseph D. Dougherty
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Intellectual and Development Developmental Disabilities Research Center, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Darshan Sapkota
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080, USA
- Department of Neuroscience, University of Texas at Dallas, Richardson, Texas 75080, USA
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6
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Tang JM, McClennan A, Liu L, Hadway J, Ronald JA, Hicks JW, Hoffman L, Anazodo UC. A Protocol for Simultaneous In Vivo Imaging of Cardiac and Neuroinflammation in Dystrophin-Deficient MDX Mice Using [ 18F]FEPPA PET. Int J Mol Sci 2023; 24:ijms24087522. [PMID: 37108685 PMCID: PMC10144317 DOI: 10.3390/ijms24087522] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 04/14/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by dystrophin loss-notably within muscles and the central neurons system. DMD presents as cognitive weakness, progressive skeletal and cardiac muscle degeneration until pre-mature death from cardiac or respiratory failure. Innovative therapies have improved life expectancy; however, this is accompanied by increased late-onset heart failure and emergent cognitive degeneration. Thus, better assessment of dystrophic heart and brain pathophysiology is needed. Chronic inflammation is strongly associated with skeletal and cardiac muscle degeneration; however, neuroinflammation's role is largely unknown in DMD despite being prevalent in other neurodegenerative diseases. Here, we present an inflammatory marker translocator protein (TSPO) positron emission tomography (PET) protocol for in vivo concomitant assessment of immune cell response in hearts and brains of a dystrophin-deficient mouse model [mdx:utrn(+/-)]. Preliminary analysis of whole-body PET imaging using the TSPO radiotracer, [18F]FEPPA in four mdx:utrn(+/-) and six wildtype mice are presented with ex vivo TSPO-immunofluorescence tissue staining. The mdx:utrn(+/-) mice showed significant elevations in heart and brain [18F]FEPPA activity, which correlated with increased ex vivo fluorescence intensity, highlighting the potential of TSPO-PET to simultaneously assess presence of cardiac and neuroinflammation in dystrophic heart and brain, as well as in several organs within a DMD model.
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Affiliation(s)
- Joanne M Tang
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - Andrew McClennan
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - Linshan Liu
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - Jennifer Hadway
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - John A Ronald
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Robarts Research Institute, Western University, London, ON N6A 3K7, Canada
| | - Justin W Hicks
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - Lisa Hoffman
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Department of Anatomy and Cell Biology, Western University, London, ON N6A 3K7, Canada
| | - Udunna C Anazodo
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
- Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 0G4, Canada
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7
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Xiao M, Hou J, Xu M, Li S, Yang B. Aquaporins in Nervous System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:99-124. [PMID: 36717489 DOI: 10.1007/978-981-19-7415-1_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Aquaporins (AQPs) mediate water flux between the four distinct water compartments in the central nervous system (CNS). In the present chapter, we mainly focus on the expression and function of the nine AQPs expressed in the CNS, which include five members of aquaporin subfamily: AQP1, AQP4, AQP5, AQP6, and AQP8; three members of aquaglyceroporin subfamily: AQP3, AQP7, and AQP9; and one member of superaquaporin subfamily: AQP11. In addition, AQP1, AQP2, and AQP4 expressed in the peripheral nervous system are also reviewed. AQP4, the predominant water channel in the CNS, is involved both in the astrocyte swelling of cytotoxic edema and the resolution of vasogenic edema and is of pivotal importance in the pathology of brain disorders such as neuromyelitis optica, brain tumors, and neurodegenerative disorders. Moreover, AQP4 has been demonstrated as a functional regulator of recently discovered glymphatic system that is a main contributor to clearance of toxic macromolecule from the brain. Other AQPs are also involved in a variety of important physiological and pathological process in the brain. It has been suggested that AQPs could represent an important target in treatment of brain disorders like cerebral edema. Future investigations are necessary to elucidate the pathological significance of AQPs in the CNS.
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Affiliation(s)
- Ming Xiao
- Jiangsu Province, Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Jiaoyu Hou
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Mengmeng Xu
- Basic Medical College, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Shao Li
- Department of Physiology, Dalian Medical University, Dalian, China
| | - Baoxue Yang
- School of Basic Medical Sciences, Peking University, Beijing, China.
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8
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Jahncke JN, Wright KM. The many roles of dystroglycan in nervous system development and function: Dystroglycan and neural circuit development: Dystroglycan and neural circuit development. Dev Dyn 2023; 252:61-80. [PMID: 35770940 DOI: 10.1002/dvdy.516] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 01/04/2023] Open
Abstract
The glycoprotein dystroglycan was first identified in muscle, where it functions as part of the dystrophin glycoprotein complex to connect the extracellular matrix to the actin cytoskeleton. Mutations in genes involved in the glycosylation of dystroglycan cause a form of congenital muscular dystrophy termed dystroglycanopathy. In addition to its well-defined role in regulating muscle integrity, dystroglycan is essential for proper central and peripheral nervous system development. Patients with dystroglycanopathy can present with a wide range of neurological perturbations, but unraveling the complex role of Dag1 in the nervous system has proven to be a challenge. Over the past two decades, animal models of dystroglycanopathy have been an invaluable resource that has allowed researchers to elucidate dystroglycan's many roles in neural circuit development. In this review, we summarize the pathways involved in dystroglycan's glycosylation and its known interacting proteins, and discuss how it regulates neuronal migration, axon guidance, synapse formation, and its role in non-neuronal cells.
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Affiliation(s)
- Jennifer N Jahncke
- Neuroscience Graduate Program, Oregan Health & Science University, Portland, Oregon, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, Portland, Oregon, USA
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9
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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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10
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The role of the dystrophin glycoprotein complex in muscle cell mechanotransduction. Commun Biol 2022; 5:1022. [PMID: 36168044 PMCID: PMC9515174 DOI: 10.1038/s42003-022-03980-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022] Open
Abstract
Dystrophin is the central protein of the dystrophin-glycoprotein complex (DGC) in skeletal and heart muscle cells. Dystrophin connects the actin cytoskeleton to the extracellular matrix (ECM). Severing the link between the ECM and the intracellular cytoskeleton has a devastating impact on the homeostasis of skeletal muscle cells, leading to a range of muscular dystrophies. In addition, the loss of a functional DGC leads to progressive dilated cardiomyopathy and premature death. Dystrophin functions as a molecular spring and the DGC plays a critical role in maintaining the integrity of the sarcolemma. Additionally, evidence is accumulating, linking the DGC to mechanosignalling, albeit this role is still less understood. This review article aims at providing an up-to-date perspective on the DGC and its role in mechanotransduction. We first discuss the intricate relationship between muscle cell mechanics and function, before examining the recent research for a role of the dystrophin glycoprotein complex in mechanotransduction and maintaining the biomechanical integrity of muscle cells. Finally, we review the current literature to map out how DGC signalling intersects with mechanical signalling pathways to highlight potential future points of intervention, especially with a focus on cardiomyopathies. A review of the function of the Dystrophic Glycoprotein Complex (DGC) in mechanosignaling provides an overview of the various components of DGC and potential mechanopathogenic mechanisms, particularly as they relate to muscular dystrophy.
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11
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Mhandire DZ, Burns DP, Roger AL, O'Halloran KD, ElMallah MK. Breathing in Duchenne muscular dystrophy: Translation to therapy. J Physiol 2022; 600:3465-3482. [PMID: 35620971 PMCID: PMC9357048 DOI: 10.1113/jp281671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease caused by a deficiency in dystrophin - a structural protein which stabilizes muscle during contraction. Dystrophin deficiency adversely affects the respiratory system leading to sleep-disordered breathing, hypoventilation, and weakness of the expiratory and inspiratory musculature, which culminate in severe respiratory dysfunction. Muscle degeneration associated respiratory impairment in neuromuscular disease is a result of disruptions at multiple sites of the respiratory control network, including sensory and motor pathways. As a result of this pathology, respiratory failure is a leading cause of premature death in DMD patients. Currently available treatments for DMD respiratory insufficiency attenuate respiratory symptoms without completely reversing the underlying pathophysiology. This underscores the need to develop curative therapies to improve quality of life and longevity of DMD patients. This review summarises research findings on the pathophysiology of respiratory insufficiencies in DMD disease in humans and animal models, the clinical interventions available to ameliorate symptoms, and gene-based therapeutic strategies uncovered by preclinical animal studies. Abstract figure legend: Summary of the therapeutic strategies for respiratory insufficiency in DMD (Duchenne muscular dystrophy). Treatment options currently in clinical use only attenuate respiratory symptoms without reversing the underlying pathology of DMD-associated respiratory insufficiencies. Ongoing preclinical and clinical research is aimed at developing curative therapies that both improve quality of life and longevity of DMD patients. AAV - adeno-associated virus, PPMO - Peptide-conjugated phosphorodiamidate morpholino oligomer This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Doreen Z Mhandire
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center Box 2644, Durham, North Carolina, 27710, USA
| | - David P Burns
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Angela L Roger
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center Box 2644, Durham, North Carolina, 27710, USA
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Mai K ElMallah
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center Box 2644, Durham, North Carolina, 27710, USA
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12
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Lange J, Gillham O, Alkharji R, Eaton S, Ferrari G, Madej M, Flower M, Tedesco FS, Muntoni F, Ferretti P. Dystrophin deficiency affects human astrocyte properties and response to damage. Glia 2022; 70:466-490. [PMID: 34773297 DOI: 10.1002/glia.24116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 01/03/2023]
Abstract
In addition to progressive muscular degeneration due to dystrophin mutations, 1/3 of Duchenne muscular dystrophy (DMD) patients present cognitive deficits. However, there is currently an incomplete understanding about the function of the multiple dystrophin isoforms in human brains. Here, we tested the hypothesis that dystrophin deficiency affects glial function in DMD and could therefore contribute to neural impairment. We investigated human dystrophin isoform expression with development and differentiation and response to damage in human astrocytes from control and induced pluripotent stem cells from DMD patients. In control cells, short dystrophin isoforms were up-regulated with development and their expression levels changed differently upon neuronal and astrocytic differentiation, as well as in 2-dimensional versus 3-dimensional astrocyte cultures. All DMD-astrocytes tested displayed altered morphology, proliferative activity and AQP4 expression. Furthermore, they did not show any morphological change in response to inflammatory stimuli and their number was significantly lower as compared to stimulated healthy astrocytes. Finally, DMD-astrocytes appeared to be more sensitive than controls to oxidative damage as shown by their increased cell death. Behavioral and metabolic defects in DMD-astrocytes were consistent with gene pathway dysregulation shared by lines with different mutations as demonstrated by bulk RNA-seq analysis. Together, our DMD model provides evidence for altered astrocyte function in DMD suggesting that defective astrocyte responses may contribute to neural impairment and might provide additional potential therapeutic targets.
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Affiliation(s)
- Jenny Lange
- Department of Developmental Biology and Cancer, Stem Cells and Regenerative Medicine Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Olivia Gillham
- Department of Developmental Biology and Cancer, Stem Cells and Regenerative Medicine Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Reem Alkharji
- Department of Developmental Biology and Cancer, Stem Cells and Regenerative Medicine Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Simon Eaton
- Department of Developmental Biology and Cancer, Stem Cells and Regenerative Medicine Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Giulia Ferrari
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Monika Madej
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Michael Flower
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Francesco Saverio Tedesco
- Department of Cell and Developmental Biology, University College London, London, UK
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- The Francis Crick Institute, 1 Midland Road, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, & Great Ormond Street Hospital Trust, London, UK
| | - Patrizia Ferretti
- Department of Developmental Biology and Cancer, Stem Cells and Regenerative Medicine Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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Preethish-Kumar V, Shah A, Kumar M, Ingalhalikar M, Polavarapu K, Afsar M, Rajeswaran J, Vengalil S, Nashi S, Thomas PT, Sadasivan A, Warrier M, Nalini A, Saini J. In Vivo Evaluation of White Matter Abnormalities in Children with Duchenne Muscular Dystrophy Using DTI. AJNR Am J Neuroradiol 2020; 41:1271-1278. [PMID: 32616576 DOI: 10.3174/ajnr.a6604] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/23/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Duchenne muscular dystrophy is an X-linked disorder characterized by progressive muscle weakness and prominent nonmotor manifestations, such as a low intelligence quotient and neuropsychiatric disturbance. We investigated WM integrity in patients with Duchenne muscular dystrophy using DTI. MATERIALS AND METHODS Fractional anisotropy and mean, axial, and radial diffusivity (DTI measures) were used to assess WM microstructural integrity along with neuropsychological evaluation in patients with Duchenne muscular dystrophy (n = 60) and controls (n = 40). Exon deletions in the DMD gene were confirmed using multiplex ligation-dependent probe amplification. Patients were classified into proximal (DMD Dp140+) and distal (DMD Dp140-) subgroups based on the location of the exon deletion and expression of short dystrophin Dp140 isoform. WM integrity was examined using whole-brain Tract-Based Spatial Statistics and atlas-based analysis of DTI data. The Pearson correlation was performed to investigate the possible relationship between neuropsychological scores and DTI metrics. RESULTS The mean ages of Duchenne muscular dystrophy and control participants were 8.0 ± 1.2 years and 8.2 ± 1.4 years, respectively. The mean age at disease onset was 4.1 ± 1.8 years, and mean illness duration was 40.8 ± 25.2 months. Significant differences in neuropsychological scores were observed between the proximal and distal gene-deletion subgroups, with more severe impairment in the distal-deletion subgroup (P < .05). Localized fractional anisotropy changes were seen in the corpus callosum, parietal WM, and fornices in the patient subgroup with Dp140+, while widespread changes were noted in the Dp140- subgroup. The Dp140+ subgroup showed increased axial diffusivity in multiple WM regions relative to the Dp140- subgroup. No significant correlation was observed between clinical and neuropsychological scores and diffusion metrics. CONCLUSIONS Widespread WM differences are evident in patients with Duchenne muscular dystrophy relative to healthy controls. Distal mutations in particular are associated with extensive WM abnormalities and poor neuropsychological profiles.
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Affiliation(s)
| | - A Shah
- Symbiosis Centre for Medical Image Analysis (A.Shah, M.I.), Symbiosis International University, Mulshi Pune, Maharashtra, India
| | - M Kumar
- Neuroimaging and Interventional Radiology (M.K., J.S.)
| | - M Ingalhalikar
- Symbiosis Centre for Medical Image Analysis (A.Shah, M.I.), Symbiosis International University, Mulshi Pune, Maharashtra, India
| | - K Polavarapu
- From the Departments of Neurology (V.P.-K., K.P., S.V., S.N., A.N.)
| | - M Afsar
- Neuropsychology (M.A., J.R.)
| | | | - S Vengalil
- From the Departments of Neurology (V.P.-K., K.P., S.V., S.N., A.N.)
| | - S Nashi
- From the Departments of Neurology (V.P.-K., K.P., S.V., S.N., A.N.)
| | - P T Thomas
- Psychiatric Social Work (P.T.T., A.Sadasivan, M.W.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - A Sadasivan
- Psychiatric Social Work (P.T.T., A.Sadasivan, M.W.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - M Warrier
- Psychiatric Social Work (P.T.T., A.Sadasivan, M.W.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - A Nalini
- From the Departments of Neurology (V.P.-K., K.P., S.V., S.N., A.N.)
| | - J Saini
- Neuroimaging and Interventional Radiology (M.K., J.S.)
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Cognitive impairment appears progressive in the mdx mouse. Neuromuscul Disord 2020; 30:368-388. [PMID: 32360405 PMCID: PMC7306157 DOI: 10.1016/j.nmd.2020.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/22/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive muscle wasting disease caused by mutations in the DMD gene, which encodes the large cytoskeletal protein dystrophin. Approximately one-third of DMD patient's exhibit cognitive problems yet it is unknown if cognitive impairments worsen with age. The mdx mouse model is deficient in dystrophin demonstrates cognitive abnormalities, but no studies have investigated this longitudinally. We assessed the consequences of dystrophin deficiency on brain morphology and cognition in male mdx mice. We utilised non-invasive methods to monitor CNS pathology with an aim to identify changes longitudinally (between 4 and 18 months old) which could be used as outcome measures. MRI identified a total brain volume (TBV) increase in control mice with ageing (p < 0.05); but the mdx mice TBV increased significantly more (p < 0.01). Voxel-based morphometry (VBM) identified decreases in grey matter volume, particularly in the hippocampus of the mdx brain, most noticeable from 12 months onwards, as were enlarged lateral ventricles in mdx mice. The caudate putamen of older mdx mice showed increases in T2- relaxometry which may be considered as evidence of increased water content. Hippocampal spatial learning and memory was decreased in mdx mice, particularly long-term memory, which progressively worsened with age. The novel object recognition (NOR) task highlighted elevated anxiety-related behaviour in older mdx mice. Our studies suggest that dystrophin deficiency causes a progressive cognitive impairment in mice (compared to ageing control mice), becoming evident at late disease stages, and may explain why progressive CNS symptoms are not obvious in DMD patients.
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15
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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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16
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Kálmán M, Oszwald E, Pócsai K. Three-plane description of astroglial populations of OVLT subdivisions in rat: Tanycyte connections to distant parts of third ventricle. J Comp Neurol 2019; 527:2793-2812. [PMID: 31045238 DOI: 10.1002/cne.24707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 11/07/2022]
Abstract
This study demonstrates glial and gliovascular markers of organon vasculosum laminae terminalis (OVLT) in three planes. The distribution of glial markers displayed similarities to the subfornical organ. There was an inner part with vimentin- and nestin-immunopositive glia whereas GFAP and the water-channel aquaporin 4 were found at the periphery. This separation indicates different functions of the two regions. The presence of nestin may indicate stem cell-capabilities whereas aquaporin 4 has been reported to promote the osmoreceptor function. Glutamine synthetase immunoreactivity was sparse like in the area postrema and subfornical organ. The laminin and β-dystroglycan immunolabelings altered along the vessels such as in the subfornical organ indicating altering gliovascular relations. The different subdivisions of OVLT received glial processes of different origins. The posterior periventricular zone contained short vimentin-immunopositive processes from the ependyma of the adjacent surface of the third ventricle. The lateral periventricular zone received forceps-like process systems from the anterolateral part of the third ventricle. Most interestingly, the "dorsal cap" received a mixed group of long GFAP- and vimentin-immunopositive processes from a distant part of the third ventricle. The processes may have two functions: a guidance for newly produced cells like radial glia in immature brain and/or a connection between distant parts of the third ventricle and OVLT.
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Affiliation(s)
- Mihály Kálmán
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Oszwald
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Károly Pócsai
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
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Effect of chronic methylphenidate treatment on hippocampal neurovascular unit and memory performance in late adolescent rats. Eur Neuropsychopharmacol 2019; 29:195-210. [PMID: 30554860 DOI: 10.1016/j.euroneuro.2018.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 11/13/2018] [Accepted: 12/01/2018] [Indexed: 12/21/2022]
Abstract
Methylphenidate (MPH) is the classic treatment for attention deficit hyperactivity disorder (ADHD) among children and adults. Despite its beneficial effects, non-medical use of MPH is nowadays a problem with high impact on society. Thus, our goal was to uncover the neurovascular and cognitive effects of MPH chronic use during a critical period of development in control conditions. For that, male Wistar Kyoto rats were treated with MPH (1.5 or 5 mg/kg/day at weekdays, per os) from P28 to P55. We concluded that the higher dose of MPH caused hippocampal blood-brain barrier (BBB) hyperpermeability by vesicular transport (transcytosis) concomitantly with the presence of peripheral immune cells in the brain parenchyma. These observations were confirmed by in vitro studies, in which the knockdown of caveolin-1 in human brain endothelial cells prevented the increased permeability and leukocytes transmigration triggered by MPH (100 µM, 24 h). Furthermore, MPH led to astrocytic atrophy and to a decrease in the levels of several synaptic proteins and impairment of AKT/CREB signaling, together with working memory deficit assessed in the Y-maze test. On the contrary, we verified that the lower dose of MPH (1.5 mg/kg/day) increased astrocytic processes and upregulated several neuronal proteins as well as signaling pathways involved in synaptic plasticity culminating in working memory improvement. In conclusion, the present study reveals that a lower dose of MPH in normal rats improves memory performance being associated with the modulation of astrocytic morphology and synaptic machinery. However, a higher dose of MPH leads to BBB dysfunction and memory impairment.
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18
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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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Pericytic Laminin Maintains Blood-Brain Barrier Integrity in an Age-Dependent Manner. Transl Stroke Res 2019; 11:228-242. [PMID: 31292838 DOI: 10.1007/s12975-019-00709-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 05/22/2019] [Accepted: 05/30/2019] [Indexed: 02/05/2023]
Abstract
Brain pericytes synthesize and deposit laminin at the blood-brain barrier (BBB). The function of pericyte-derived laminin in BBB maintenance remains largely unknown. In a previous study, we generated pericytic laminin conditional knockout (PKO) mice, which developed BBB breakdown and hydrocephalus in a mixed genetic background. However, since hydrocephalus itself can compromise BBB integrity, it remains unclear whether BBB disruption in these mutants is due to loss of pericytic laminin or secondary to hydrocephalus. Here, we report that, in C57Bl6 dominant background, the PKO mice fail to show hydrocephalus, have a normal lifespan, and develop BBB breakdown in an age-dependent manner. Further mechanistic studies demonstrate that abnormal paracellular transport, enhanced transcytosis, decreased pericyte coverage, and diminished AQP4 level are responsible for BBB disruption in PKO mice. These results suggest that pericyte-derived laminin plays an indispensable and age-dependent role in the maintenance of BBB integrity under homeostatic conditions.
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20
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Podkalicka P, Mucha O, Dulak J, Loboda A. Targeting angiogenesis in Duchenne muscular dystrophy. Cell Mol Life Sci 2019; 76:1507-1528. [PMID: 30770952 PMCID: PMC6439152 DOI: 10.1007/s00018-019-03006-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 12/28/2018] [Accepted: 01/07/2019] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) represents one of the most devastating types of muscular dystrophies which affect boys already at early childhood. Despite the fact that the primary cause of the disease, namely the lack of functional dystrophin is known already for more than 30 years, DMD still remains an incurable disease. Thus, an enormous effort has been made during recent years to reveal novel mechanisms that could provide therapeutic targets for DMD, especially because glucocorticoids treatment acts mostly symptomatic and exerts many side effects, whereas the effectiveness of genetic approaches aiming at the restoration of functional dystrophin is under the constant debate. Taking into account that dystrophin expression is not restricted to muscle cells, but is present also in, e.g., endothelial cells, alterations in angiogenesis process have been proposed to have a significant impact on DMD progression. Indeed, already before the discovery of dystrophin, several abnormalities in blood vessels structure and function have been revealed, suggesting that targeting angiogenesis could be beneficial in DMD. In this review, we will summarize current knowledge about the angiogenesis status both in animal models of DMD as well as in DMD patients, focusing on different organs as well as age- and sex-dependent effects. Moreover, we will critically discuss some approaches such as modulation of vascular endothelial growth factor or nitric oxide related pathways, to enhance angiogenesis and attenuate the dystrophic phenotype. Additionally, we will suggest the potential role of other mediators, such as heme oxygenase-1 or statins in those processes.
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Affiliation(s)
- Paulina Podkalicka
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Olga Mucha
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Jozef Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Agnieszka Loboda
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
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Górecki DC. P2X7 purinoceptor as a therapeutic target in muscular dystrophies. Curr Opin Pharmacol 2019; 47:40-45. [PMID: 30901735 DOI: 10.1016/j.coph.2019.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/05/2019] [Accepted: 02/15/2019] [Indexed: 01/07/2023]
Abstract
Mutations in the dystrophin and sarcoglycans genes result in muscular dystrophies causing severe disability and premature death and where no effective treatment is available. New therapeutic approaches targeting secondary disease mechanisms have a strong translational potential. Dystrophic muscle damage triggers release of ATP whilst loss of ecto-ATPase activity of sarcoglycan further elevates extracellular ATP (eATP) levels. Such a high eATP activates P2X7 purinoceptors on immune cells; these contribute to chronic inflammatory and immune responses that exacerbate the dystrophic pathology. Dystrophin mutations coincide with a significant P2X7 upregulation in Duchenne muscular dystrophy (DMD) muscle and alter receptor signalling in mouse dystrophic myoblasts and myofibers. P2X7 overexpression combined with the eATP-rich environment lead to cell dysfunction and death and ultimately to ineffective regeneration. P2X7 is therefore a therapeutic target for reducing damaging inflammation and supporting the repair of dystrophic muscles. Accordingly, genetic ablation and pharmacological inhibition of the eATP-P2X7 axis alleviated dystrophic phenotypes in mouse models of dystrophinopathy and sarcoglycanopathy. Thus, P2X7 inhibitors are good candidates for rapid re-purposing for the treatment of these highly debilitating diseases. Such a therapy is not constrained by causative mutations, so it would be suitable for all patients. Moreover, it appears effective in alleviating both muscle and non-muscle symptoms.
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Affiliation(s)
- Dariusz C Górecki
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK; Military Institute of Hygiene and Epidemiology, Warsaw, Poland.
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22
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Kálmán M, Lőrincz DL, Sebők OM, Ari C, Oszwald E, Somiya H, Jancsik V. Cerebrovascular β-dystroglycan immunoreactivity in vertebrates: not detected in anurans and in the teleosts Ostariophysi and Euteleostei. Integr Zool 2019; 15:16-31. [PMID: 30811839 DOI: 10.1111/1749-4877.12384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The aim of the present paper was to check for the presence of cerebrovascular dystroglycan in vertebrates, because dystroglycan, which is localized in the vascular astroglial end-feet, has a pivotal function in glio-vascular connections. In mammalian brains, the immunoreactivity of β-dystroglycan subunit delineates the vessels. The results of the present study demonstrate similar patterns in other vertebrates, except for anurans and the teleost groups Ostariophysi and Euteleostei. In this study, we investigated 1 or 2 representative species of the main groups of Chondrichthyes, teleost and non-teleost ray-finned fishes, urodeles, anurans, and reptiles. We also investigated 5 mammalian and 3 bird species. Animals were obtained from breeders or fishermen. The presence of β-dystroglycan was investigated immunohistochemically in free-floating sections. Pre-embedding electron microscopical immunohistochemistry on Heterodontus japonicus shark brains demonstrated that in Elasmobranchii, β-dystroglycan is also localized in the perivascular glial end-feet despite the different construction of their blood-brain barrier. The results indicated that the cerebrovascular β-dystroglycan immunoreactivity disappeared separately in anurans, and in teleosts, in the latter group before its division to Ostariophysi and Euteleostei. Immunohistochemistry in muscles and western blots from brain homogenates, however, detected the presence of β-dystroglycan, even in anurans and all teleosts. A possible explanation is that in the glial end-feet, β-dystroglycan is masked in these animals, or disappeared during adaptation to the freshwater habitat.
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Affiliation(s)
- Mihály Kálmán
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - David L Lőrincz
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.,University of Leicester, Dept. of Neuroscience, Psychology and Behaviour, Leicester, United Kingdom
| | - Olivér M Sebők
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Csilla Ari
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.,Hyperbaric Neuroscience Research Lab., Dept of Psychology, University of South Florida, Tampa, Florida, USA
| | - Erzsébet Oszwald
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Hiroaki Somiya
- Department of Environmental Biology, Chubu University, Chubu, Japan
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23
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Tham DKL, Moukhles H. Towards a better understanding of AQP4's role in astrocytic process extension: An Editorial for 'Involvement of aquaporin-4 in laminin-enhanced process formation of mouse astrocytes in 2D culture: Roles of dystroglycan and a-syntrophin in aquaporin-4 expression' on page 495. J Neurochem 2018; 147:436-438. [PMID: 30378126 DOI: 10.1111/jnc.14590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 09/06/2018] [Indexed: 11/30/2022]
Abstract
At the blood-brain-barrier (BBB), blood vessels are surrounded by the endfoot structures formed by astroglial cells. The latter are themselves part of a larger syncytial network of astrocytes connected to each other via a complex web of processes. The water-permeable channel aquaporin-4 (AQP4) is expressed at high concentrations at these endfeet, held in place by the dystrophin glycoprotein complex (DGC), a collection of proteins that act as a bridge linking AQP4 to the laminin-containing basal lamina found in between the blood vessels and the astrocytic endfeet. Although AQP4, supported by the DGC, has well-established roles in facilitating certain neurological processes, and in mediating the removal of excess water from the brain in certain disease states, relatively few studies have looked at the importance of these components in the regulation of the extension of the processes that are so characteristic of astrocytes. In this Editorial Highlight, we discuss an article by Sato et al., published in this issue of the Journal of Neurochemistry, which attempts to address this question.
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Affiliation(s)
- Daniel Kai Long Tham
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hakima Moukhles
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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24
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Sifi M, Benabdesselam R, Souttou S, Annese T, Rendon A, Nico B, Dorbani-Mamine L. Dystrophin 71 and α1syntrophin in morpho-functional plasticity of rat supraoptic nuclei: Effect of saline surcharge and reversibly normal hydration. Acta Histochem 2018; 120:187-195. [PMID: 29395317 DOI: 10.1016/j.acthis.2018.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/25/2017] [Accepted: 01/09/2018] [Indexed: 02/02/2023]
Abstract
Dystrophin (Dp) is a multidomain protein that links the actin cytoskeleton to the extracellular matrix through the dystrophin associated proteins complex (DAPC). Dp of 71 kDa (Dp71), corresponding to the COOH-terminal domain of dystrophin, and α1-syntrophin (α1Syn) as the principal component of the DAPC, are strongly expressed in the brain. To clarify their involvement in the central control of osmotic homeostasis, we investigated the effect of 14 days of salt loading (with drinking water containing 2% NaCl) and then reversibly to 30 days of normal hydration (with drinking water without salt), first on the expression by western-blotting and the distribution by immunochemistry of Dp71 and α1Syn in the SON of the rat and, second, on the level of some physiological parameters, as the plasma osmolality, natremia and hematocrit. Dp71 is the most abundant form of dystrophin revealed in the supraoptic nucleu (SON) of control rat. Dp71 was localized in magnocellular neurons (MCNs) and astrocytes, when α1Syn was observed essentially in astrocytes end feet. After 14 days of salt-loading, Dp71 and α1Syn signals decreased and a dual signal for these two proteins was revealed in the astrocytes processes SON surrounding blood capillaries. In addition, salt loading leads to an increase in plasma osmolality, natremia and hematocrit. Reversibly, after 30 days of normal hydration, the intensity of the signal for the two proteins, Dp71 and α1Syn, increased and approached that of control. Furtheremore, the levels of the physiological parameters decreased and approximated those of control. This suggests that Dp71 and α1Syn may be involved in the functional activity of the SON. Their localization in astrocyte end feet emphasizes their importance in neuronal-vascular-astrocyte interactions for the central detection of osmolality. In the SON, Dp71 and α1Syn may be involved in osmosensitivity.
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Affiliation(s)
- Madina Sifi
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
| | - Roza Benabdesselam
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria; Département de Biologie, Faculté des Sciences Biologiques et Agronomiques, UMMTO, Tizi Ouzou, Algeria.
| | - Sabrina Souttou
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organes, University of Bari "Aldo Moro", Bari, Italy
| | - Alvaro Rendon
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine, INSERM UMRS-592, Institut de la Vision, Paris, France
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organes, University of Bari "Aldo Moro", Bari, Italy
| | - Latifa Dorbani-Mamine
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
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25
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Dp71 is regulated by phosphorylation and ubiquitin-proteasome system in neuronal cells. Biochem Biophys Res Commun 2017; 492:349-355. [PMID: 28851655 DOI: 10.1016/j.bbrc.2017.08.108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 08/26/2017] [Indexed: 01/29/2023]
Abstract
The Dystrophin (Dp) gene is responsible for Duchenne muscular dystrophy (DMD), which is characterized by progressive muscular degeneration and variable degrees of cognitive impairment. Although Dp71 is the most abundant among the Dp isoforms in the brain, the regulatory mechanisms of the related expression levels have not been elucidated. In this study, we found that the constitutive expression levels of Dp71 in PC12 cells were sensitive to proteasomal inhibition. The ectopic expression of FLAG-tagged ubiquitin revealed that Dp71 was ubiquitinated intracellularly. Interestingly, proteasomal inhibition was accompanied by a posttranslational accumulation of modified Dp71, which was restored by protein phosphatase treatment in vitro, indicating that phosphorylation is responsible for the modification and affects the proteasome-dependent degradation of Dp71. Proteasomal activity-sensitive phosphorylated Dp71 is closely associated with syntrophin, a well-known binding partner of Dp71, and syntrophin is also regulated by proteasomal activity in a similar way to Dp71, suggesting that the posttranslational regulatory machinery for Dp71 level is coupled with Dp71-syntrophin molecular complex. Taken together, our results indicated that the expression levels of Dp71 are posttranslationally regulated by the phosphorylation-ubiquitin-proteasomal pathway, which may indicate the presence of regulatory mechanisms underlying the proteostasis of both Dp and its molecular complex, which may lead to better therapeutic approaches for the treatment of Dp-related diseases.
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26
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Suzuki Y, Higuchi S, Aida I, Nakajima T, Nakada T. Abnormal distribution of GABA A receptors in brain of duchenne muscular dystrophy patients. Muscle Nerve 2017; 55:591-595. [PMID: 27543743 DOI: 10.1002/mus.25383] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2016] [Indexed: 11/06/2022]
Abstract
INTRODUCTION In this study we sought to: (1) determine the distribution of GABAA receptors (GABAA -Rs) in the brain of Duchenne muscular dystrophy (DMD) patients; and (2) ascertain if the distribution pattern correlates with cognitive dysfunction. METHODS Fourteen DMD patients [young adult (n = 7, 18-25 years old) and older adult (n = 7, 30-37 years old) groups] and 16 age-matched normal volunteers participated. GABAA -R distribution was assessed using 123 I-IMZ-SPECT. Neuropsychological assessments were performed using 3 different test batteries, the WAIS-III, WMS-R, and Wisconsin Card Sorting Test (WCST). RESULTS All DMD patients showed significant decline in 123 I-IMZ uptake in the prefrontal cortex (P < 0.05). Although no differences were detected in the WAIS-III and WMS-R, the WCST scores of DMD patients (2.8 ± 1.9) were significantly lower (P < 0.01) than those of normal volunteers (5.4 ± 0.7). Both abnormalities were more pronounced in older adult patients. CONCLUSION The findings demonstrate that DMD is accompanied by a reduction in the prefrontal cortex distribution of GABAA -Rs. Muscle Nerve 55: 591-595, 2017.
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Affiliation(s)
- Yuji Suzuki
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, 1-757 Asahimachi, Niigata, 951-8585, Japan.,National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Shinya Higuchi
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Izumi Aida
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Takashi Nakajima
- National Hospital Organization, Niigata National Hospital, Niigata, Japan
| | - Tsutomu Nakada
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, 1-757 Asahimachi, Niigata, 951-8585, Japan
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27
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Abstract
Aquaporins (AQPs ) mediate water flux between the four distinct water compartments in the central nervous system (CNS). In the present chapter, we mainly focus on the expression and function of the 9 AQPs expressed in the CNS, which include five members of aquaporin subfamily: AQP1, AQP4, AQP5, AQP6, and AQP8; three members of aquaglyceroporin subfamily: AQP3, AQP7, and AQP9; and one member of superaquaporin subfamily: AQP11. In addition, AQP1, AQP2 and AQP4 expressed in the peripheral nervous system (PNS) are also reviewed. AQP4, the predominant water channel in the CNS, is involved both in the astrocyte swelling of cytotoxic edema and the resolution of vasogenic edema, and is of pivotal importance in the pathology of brain disorders such as neuromyelitis optica , brain tumors and Alzheimer's disease. Other AQPs are also involved in a variety of important physiological and pathological process in the brain. It has been suggested that AQPs could represent an important target in treatment of brain disorders like cerebral edema. Future investigations are necessary to elucidate the pathological significance of AQPs in the CNS.
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28
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Gautam J, Zhang X, Yao Y. The role of pericytic laminin in blood brain barrier integrity maintenance. Sci Rep 2016; 6:36450. [PMID: 27808256 PMCID: PMC5093438 DOI: 10.1038/srep36450] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/14/2016] [Indexed: 11/09/2022] Open
Abstract
Laminin, a major component of the basement membrane, plays an important role in blood brain barrier regulation. At the neurovascular unit, brain endothelial cells, astrocytes, and pericytes synthesize and deposit different laminin isoforms into the basement membrane. It has been shown that laminin α4 (endothelial laminin) regulates vascular integrity at embryonic/neonatal stage, while astrocytic laminin maintains vascular integrity in adulthood. Here, we investigate the function of pericyte-derived laminin in vascular integrity. Using a conditional knockout mouse line, we report that loss of pericytic laminin leads to hydrocephalus and BBB breakdown in a small percentage (10.7%) of the mutants. Interestingly, BBB disruption always goes hand-in-hand with hydrocephalus in these mutants, and neither symptom is observed in the rest 89.3% of the mutants. Further mechanistic studies show that reduced tight junction proteins, diminished AQP4 expression, and decreased pericyte coverage are responsible for the BBB disruption. Together, these data suggest that pericyte-derived laminin is involved in the maintenance of BBB integrity and regulation of ventricular size/development.
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Affiliation(s)
- Jyoti Gautam
- College of Pharmacy, University of Minnesota, 1110 Kirby Drive, Duluth, MN, 55812, USA
| | - Xuanming Zhang
- College of Pharmacy, University of Minnesota, 1110 Kirby Drive, Duluth, MN, 55812, USA
| | - Yao Yao
- College of Pharmacy, University of Minnesota, 1110 Kirby Drive, Duluth, MN, 55812, USA
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29
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Boulay AC, Cisternino S, Cohen-Salmon M. Immunoregulation at the gliovascular unit in the healthy brain: A focus on Connexin 43. Brain Behav Immun 2016; 56:1-9. [PMID: 26674996 DOI: 10.1016/j.bbi.2015.11.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/26/2015] [Accepted: 11/28/2015] [Indexed: 01/18/2023] Open
Abstract
In the brain, immune cell infiltration is normally kept at a very low level and a unique microenvironment strictly restricts immune reactions and inflammation. Even in such quiescent environment, a constant immune surveillance is at work allowing the brain to rapidly react to threats. To date, knowledge about the factors regulating the brain-immune system interrelationship in healthy conditions remains elusive. Interestingly, astrocytes, the most abundant glial cells in the brain, may participate in many aspects of this unique homeostasis, in particular due to their close interaction with the brain vascular system and expression of a specific molecular repertoire. Indeed, astrocytes maintain the blood-brain barrier (BBB) integrity, interact with immune cells, and participate in the regulation of intracerebral liquid movements. We recently showed that Connexin 43 (Cx43), a gap junction protein highly expressed by astrocytes at the BBB interface, is an immunoregulating factor. The absence of astroglial Cx43 leads to a transient endothelial activation, a continuous immune recruitment as well as the development of a specific humoral autoimmune response against the von Willebrand factor A domain-containing protein 5a, an extracellular matrix protein expressed by astrocytes. In this review, we propose to gather current knowledge on how astrocytes may influence the immune system in the healthy brain, focusing on their roles at the gliovascular interface. We will also consider pathological situations involving astrocyte-specific autoimmunities. Finally, we will discuss the specific role of astroglial Cx43 and the physiological consequences of immune regulations taking place on inflammation, cognition and behavior in the absence of Cx43.
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Affiliation(s)
- Anne-Cécile Boulay
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Centre National de la Recherche Scientifique CNRS, Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale INSERM, U1050, Neuroglial Interactions in Cerebral Physiopathology, 75231 Paris Cedex 05, France; University Pierre et Marie Curie, ED, N°158, 75005 Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France
| | - Salvatore Cisternino
- Variabilité de réponse aux psychotropes, INSERM, U1144, Paris F-75006, France; Université Paris Descartes, Faculté de Pharmacie, UMR-S 1144, 75006 Paris, France; Université Paris Diderot, UMR-S 1144, 75013 Paris, France
| | - Martine Cohen-Salmon
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Centre National de la Recherche Scientifique CNRS, Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale INSERM, U1050, Neuroglial Interactions in Cerebral Physiopathology, 75231 Paris Cedex 05, France; University Pierre et Marie Curie, ED, N°158, 75005 Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France.
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30
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Rae MG, O'Malley D. Cognitive dysfunction in Duchenne muscular dystrophy: a possible role for neuromodulatory immune molecules. J Neurophysiol 2016; 116:1304-15. [PMID: 27385793 DOI: 10.1152/jn.00248.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/29/2016] [Indexed: 11/22/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X chromosome-linked disease characterized by progressive physical disability, immobility, and premature death in affected boys. Underlying the devastating symptoms of DMD is the loss of dystrophin, a structural protein that connects the extracellular matrix to the cell cytoskeleton and provides protection against contraction-induced damage in muscle cells, leading to chronic peripheral inflammation. However, dystrophin is also expressed in neurons within specific brain regions, including the hippocampus, a structure associated with learning and memory formation. Linked to this, a subset of boys with DMD exhibit nonprogressing cognitive dysfunction, with deficits in verbal, short-term, and working memory. Furthermore, in the genetically comparable dystrophin-deficient mdx mouse model of DMD, some, but not all, types of learning and memory are deficient, and specific deficits in synaptogenesis and channel clustering at synapses has been noted. Little consideration has been devoted to the cognitive deficits associated with DMD compared with the research conducted into the peripheral effects of dystrophin deficiency. Therefore, this review focuses on what is known about the role of full-length dystrophin (Dp427) in hippocampal neurons. The importance of dystrophin in learning and memory is assessed, and the potential importance that inflammatory mediators, which are chronically elevated in dystrophinopathies, may have on hippocampal function is also evaluated.
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Affiliation(s)
- Mark G Rae
- Department of Physiology, University College Cork, Cork, Ireland; and
| | - Dervla O'Malley
- Department of Physiology, University College Cork, Cork, Ireland; and APC Microbiome Institute, University College Cork, Cork, Ireland
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31
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Petkova MV, Morales-Gonzales S, Relizani K, Gill E, Seifert F, Radke J, Stenzel W, Garcia L, Amthor H, Schuelke M. Characterization of a Dmd (EGFP) reporter mouse as a tool to investigate dystrophin expression. Skelet Muscle 2016; 6:25. [PMID: 27382459 PMCID: PMC4932663 DOI: 10.1186/s13395-016-0095-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dystrophin is a rod-shaped cytoplasmic protein that provides sarcolemmal stability as a structural link between the cytoskeleton and the extracellular matrix via the dystrophin-associated protein complex (DAPC). Mutations in the dystrophin-encoding DMD gene cause X-linked dystrophinopathies with variable phenotypes, the most severe being Duchenne muscular dystrophy (DMD) characterized by progressive muscle wasting and fibrosis. However, dystrophin deficiency does not only impair the function of skeletal and heart muscle but may also affect other organ systems such as the brain, eye, and gastrointestinal tract. The generation of a dystrophin reporter mouse would facilitate research into dystrophin muscular and extramuscular pathophysiology without the need for immunostaining. RESULTS We generated a Dmd (EGFP) reporter mouse through the in-frame insertion of the EGFP coding sequence behind the last Dmd exon 79, which is known to be expressed in all major dystrophin isoforms. We analyzed EGFP and dystrophin expression in various tissues and at the single muscle fiber level. Immunostaining of various members of the DAPC was done to confirm the correct subsarcolemmal location of dystrophin-binding partners. We found strong natural EGFP fluorescence at all expected sites of dystrophin expression in the skeletal and smooth muscle, heart, brain, and retina. EGFP fluorescence exactly colocalized with dystrophin immunostaining. In the skeletal muscle, dystrophin and other proteins of the DAPC were expressed at their correct sarcolemmal/subsarcolemmal localization. Skeletal muscle maintained normal tissue architecture, suggesting the correct function of the dystrophin-EGFP fusion protein. EGFP expression could be easily verified in isolated myofibers as well as in satellite cell-derived myotubes. CONCLUSIONS The novel dystrophin reporter mouse provides a valuable tool for direct visualization of dystrophin expression and will allow the study of dystrophin expression in vivo and in vitro in various tissues by live cell imaging.
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Affiliation(s)
- Mina V Petkova
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Susanne Morales-Gonzales
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karima Relizani
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Esther Gill
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Franziska Seifert
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Josefine Radke
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Werner Stenzel
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Luis Garcia
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Helge Amthor
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Markus Schuelke
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
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32
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Annese T, Corsi P, Ruggieri S, Tamma R, Marinaccio C, Picocci S, Errede M, Specchia G, De Luca A, Frassanito MA, Desantis V, Vacca A, Ribatti D, Nico B. Isolation and characterization of neural stem cells from dystrophic mdx mouse. Exp Cell Res 2016; 343:190-207. [DOI: 10.1016/j.yexcr.2016.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 03/17/2016] [Accepted: 03/19/2016] [Indexed: 10/22/2022]
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33
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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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Murphy S, Zweyer M, Henry M, Meleady P, Mundegar RR, Swandulla D, Ohlendieck K. Label-free mass spectrometric analysis reveals complex changes in the brain proteome from the mdx-4cv mouse model of Duchenne muscular dystrophy. Clin Proteomics 2015; 12:27. [PMID: 26604869 PMCID: PMC4657206 DOI: 10.1186/s12014-015-9099-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/13/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND X-linked muscular dystrophy is a primary disease of the neuromuscular system. Primary abnormalities in the Dmd gene result in the absence of the full-length isoform of the membrane cytoskeletal protein dystrophin. Besides progressive skeletal muscle wasting and cardio-respiratory complications, developmental cognitive deficits and behavioural abnormalities are clinical features of Duchenne muscular dystrophy. In order to better understand the mechanisms that underlie impaired brain functions in Duchenne patients, we have carried out a proteomic analysis of total brain extracts from the mdx-4cv mouse model of dystrophinopathy. RESULTS The comparative proteomic profiling of the mdx-4cv brain revealed a significant increase in 39 proteins and a decrease in 7 proteins. Interesting brain tissue-associated proteins with an increased concentration in the mdx-4cv animal model were represented by the glial fibrillary acidic protein GFAP, the neuronal Ca(2+)-binding protein calretinin, annexin AnxA5, vimentin, the neuron-specific enzyme ubiquitin carboxyl-terminal hydrolase isozyme L1, the dendritic spine protein drebrin, the cytomatrix protein bassoon of the nerve terminal active zone, and the synapse-associated protein SAP97. Decreased proteins were identified as the nervous system-specific proteins syntaxin-1B and syntaxin-binding protein 1, as well as the plasma membrane Ca(2+)-transporting ATPase PMCA2 that is mostly found in the brain cortex. The differential expression patterns of GFAP, vimentin, PMCA2 and AnxA5 were confirmed by immunoblotting. Increased GFAP levels were also verified by immunofluorescence microscopy. CONCLUSIONS The large number of mass spectrometrically identified proteins with an altered abundance suggests complex changes in the mdx-4cv brain proteome. Increased levels of the glial fibrillary acidic protein, an intermediate filament component that is uniquely associated with astrocytes in the central nervous system, imply neurodegeneration-associated astrogliosis. The up-regulation of annexin and vimentin probably represent compensatory mechanisms involved in membrane repair and cytoskeletal stabilization in the absence of brain dystrophin. Differential alterations in the Ca(2+)-binding protein calretinin and the Ca(2+)-pumping protein PMCA2 suggest altered Ca(2+)-handling mechanisms in the Dp427-deficient brain. In addition, the proteomic findings demonstrated metabolic adaptations and functional changes in the central nervous system from the dystrophic phenotype. Candidate proteins can now be evaluated for their suitability as proteomic biomarkers and their potential in predictive, diagnostic, prognostic and/or therapy-monitoring approaches to treat brain abnormalities in dystrophinopathies.
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Affiliation(s)
- Sandra Murphy
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare Ireland
| | - Margit Zweyer
- Department of Physiology II, University of Bonn, 53115 Bonn, Germany
| | - Michael Henry
- National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland
| | - Paula Meleady
- National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland
| | - Rustam R Mundegar
- Department of Physiology II, University of Bonn, 53115 Bonn, Germany
| | - Dieter Swandulla
- Department of Physiology II, University of Bonn, 53115 Bonn, Germany
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare Ireland
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Sinadinos A, Young CNJ, Al-Khalidi R, Teti A, Kalinski P, Mohamad S, Floriot L, Henry T, Tozzi G, Jiang T, Wurtz O, Lefebvre A, Shugay M, Tong J, Vaudry D, Arkle S, doRego JC, Górecki DC. P2RX7 purinoceptor: a therapeutic target for ameliorating the symptoms of duchenne muscular dystrophy. PLoS Med 2015; 12:e1001888. [PMID: 26461208 PMCID: PMC4604078 DOI: 10.1371/journal.pmed.1001888] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 09/04/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is the most common inherited muscle disease, leading to severe disability and death in young men. Death is caused by the progressive degeneration of striated muscles aggravated by sterile inflammation. The pleiotropic effects of the mutant gene also include cognitive and behavioral impairments and low bone density. Current interventions in DMD are palliative only as no treatment improves the long-term outcome. Therefore, approaches with a translational potential should be investigated, and key abnormalities downstream from the absence of the DMD product, dystrophin, appear to be strong therapeutic targets. We and others have demonstrated that DMD mutations alter ATP signaling and have identified P2RX7 purinoceptor up-regulation as being responsible for the death of muscles in the mdx mouse model of DMD and human DMD lymphoblasts. Moreover, the ATP-P2RX7 axis, being a crucial activator of innate immune responses, can contribute to DMD pathology by stimulating chronic inflammation. We investigated whether ablation of P2RX7 attenuates the DMD model mouse phenotype to assess receptor suitability as a therapeutic target. METHODS AND FINDINGS Using a combination of molecular, histological, and biochemical methods and behavioral analyses in vivo we demonstrate, to our knowledge for the first time, that genetic ablation of P2RX7 in the DMD model mouse produces a widespread functional attenuation of both muscle and non-muscle symptoms. In dystrophic muscles at 4 wk there was an evident recovery in key functional and molecular parameters such as improved muscle structure (minimum Feret diameter, p < 0.001), increased muscle strength in vitro (p < 0.001) and in vivo (p = 0.012), and pro-fibrotic molecular signatures. Serum creatine kinase (CK) levels were lower (p = 0.025), and reduced cognitive impairment (p = 0.006) and bone structure alterations (p < 0.001) were also apparent. Reduction of inflammation and fibrosis persisted at 20 mo in leg (p = 0.038), diaphragm (p = 0.042), and heart muscles (p < 0.001). We show that the amelioration of symptoms was proportional to the extent of receptor depletion and that improvements were observed following administration of two P2RX7 antagonists (CK, p = 0.030 and p = 0.050) without any detectable side effects. However, approaches successful in animal models still need to be proved effective in clinical practice. CONCLUSIONS These results are, to our knowledge, the first to establish that a single treatment can improve muscle function both short and long term and also correct cognitive impairment and bone loss in DMD model mice. The wide-ranging improvements reflect the convergence of P2RX7 ablation on multiple disease mechanisms affecting skeletal and cardiac muscles, inflammatory cells, brain, and bone. Given the impact of P2RX7 blockade in the DMD mouse model, this receptor is an attractive target for translational research: existing drugs with established safety records could potentially be repurposed for treatment of this lethal disease.
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Affiliation(s)
- Anthony Sinadinos
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Christopher N. J. Young
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Rasha Al-Khalidi
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Anna Teti
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy
| | - Paweł Kalinski
- Departments of Surgery, Immunology, and Bioengineering, School of Medicine, University of Pittsburgh, Pittsburg, Pennsylvania, United States of America
| | - Shafini Mohamad
- School of Engineering, University of Portsmouth, Portsmouth, United Kingdom
| | - Léonore Floriot
- Platform of Behavioural Analysis (SCAC), University of Rouen, Mont-Saint-Aignan,Rouen, France
| | - Tiphaine Henry
- Platform of Behavioural Analysis (SCAC), University of Rouen, Mont-Saint-Aignan,Rouen, France
| | - Gianluca Tozzi
- School of Engineering, University of Portsmouth, Portsmouth, United Kingdom
| | - Taiwen Jiang
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Olivier Wurtz
- INSERM U982, Plate-Forme d’Imagerie PRIMACEN, IRIB, University of Rouen, Mont-Saint-Aignan, France
| | - Alexis Lefebvre
- Platform of Behavioural Analysis (SCAC), University of Rouen, Mont-Saint-Aignan,Rouen, France
| | - Mikhail Shugay
- Genomics of Adaptive Immunity Lab, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry and Pirogov Russian National Research Medical University, Moscow, Russia
| | - Jie Tong
- School of Engineering, University of Portsmouth, Portsmouth, United Kingdom
| | - David Vaudry
- INSERM U982, Plate-Forme d’Imagerie PRIMACEN, IRIB, University of Rouen, Mont-Saint-Aignan, France
| | - Stephen Arkle
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Jean-Claude doRego
- Platform of Behavioural Analysis (SCAC), University of Rouen, Mont-Saint-Aignan,Rouen, France
- National Center of Scientific Research (CNRS), Caen, France
| | - Dariusz C. Górecki
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
- * E-mail:
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36
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Brignone MS, Lanciotti A, Camerini S, De Nuccio C, Petrucci TC, Visentin S, Ambrosini E. MLC1 protein: a likely link between leukodystrophies and brain channelopathies. Front Cell Neurosci 2015; 9:66. [PMID: 25883547 PMCID: PMC4381631 DOI: 10.3389/fncel.2015.00106] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/09/2015] [Indexed: 01/12/2023] Open
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLCs) disease is a rare inherited, autosomal recessive form of childhood-onset spongiform leukodystrophy characterized by macrocephaly, deterioration of motor functions, epileptic seizures and mental decline. Brain edema, subcortical fluid cysts, myelin and astrocyte vacuolation are the histopathological hallmarks of MLC. Mutations in either the MLC1 gene (>75% of patients) or the GlialCAM gene (<20% of patients) are responsible for the disease. Recently, the GlialCAM adhesion protein was found essential for the membrane expression and function of the chloride channel ClC-2 indicating MLC disease caused by mutation in GlialCAM as the first channelopathy among leukodystrophies. On the contrary, the function of MLC1 protein, which binds GlialCAM, its functional relationship with ClC-2 and the molecular mechanisms underlying MLC1 mutation-induced functional defects are not fully understood yet. The human MLC1 gene encodes a 377-amino acid membrane protein with eight predicted transmembrane domains which shows very low homology with voltage-dependent potassium (K+) channel subunits. The high expression of MLC1 in brain astrocytes contacting blood vessels and meninges and brain alterations observed in MLC patients have led to hypothesize a role for MLC1 in the regulation of ion and water homeostasis. Recent studies have shown that MLC1 establishes structural and/or functional interactions with several ion/water channels and transporters and ion channel accessory proteins, and that these interactions are affected by MLC1 mutations causing MLC. Here, we review data on MLC1 functional properties obtained in in vitro and in vivo models and discuss evidence linking the effects of MLC1 mutations to brain channelopathies.
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Affiliation(s)
- Maria S Brignone
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Angela Lanciotti
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Serena Camerini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Chiara De Nuccio
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Tamara C Petrucci
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Sergio Visentin
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
| | - Elena Ambrosini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità Rome, Italy
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Hendriksen RG, Hoogland G, Schipper S, Hendriksen JG, Vles JS, Aalbers MW. A possible role of dystrophin in neuronal excitability: A review of the current literature. Neurosci Biobehav Rev 2015; 51:255-62. [DOI: 10.1016/j.neubiorev.2015.01.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 01/18/2015] [Accepted: 01/31/2015] [Indexed: 10/24/2022]
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38
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Pócsai K, Kálmán M. Glial and perivascular structures in the subfornical organ: distinguishing the shell and core. J Histochem Cytochem 2015; 63:367-83. [PMID: 25673286 DOI: 10.1369/0022155415575027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 01/25/2015] [Indexed: 11/22/2022] Open
Abstract
The subfornical organ (SFO) is a circumventricular organ with a chemosensitive function, and its vessels have no blood-brain barrier. Our study investigated the glial and vascular components in the SFO to determine whether their distributions indicate subdivisions, how to characterize the vessels and how to demarcate the SFO. To this end, we investigated glial markers (GFAP, glutamine synthetase, S100) and other markers, including vimentin and nestin (immature glia), laminin (basal lamina), β-dystroglycan (glio-vascular connections), and aquaporin 4 (glial water channels). We determined that the 'shell' of the SFO was marked by immunoreactivity for S100, GFAP and aquaporin 4. Nestin immunoreactivity was characteristic of the 'core'. Vimentin was almost evenly distributed. Glutamine synthetase immunoreactivity occurred in the shell but its expression was sparse. Vessels in the core were decorated with laminin but showed a discontinuous expression of aquaporin 4. Vimentin and GFAP staining was usually in separate glial elements, which may be related to their functional differences. Similar to other vessels in the brain, β-dystroglycan was detected along the shell vessels but laminin was not. The gradual disappearance of the laminin immunopositivity was attributed to the gradual disappearance of the perivascular space. Thus, our findings suggest that the shell and core glio-vascular structures are adapted to different sensory functions: osmoperception and the perception of circulating peptides, respectively.
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Affiliation(s)
- Károly Pócsai
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary (KP, MK)
| | - Mihály Kálmán
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary (KP, MK)
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The extracellular matrix protein laminin α2 regulates the maturation and function of the blood-brain barrier. J Neurosci 2015; 34:15260-80. [PMID: 25392494 DOI: 10.1523/jneurosci.3678-13.2014] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Laminins are major constituents of the gliovascular basal lamina of the blood-brain barrier (BBB); however, the role of laminins in BBB development remains unclear. Here we report that Lama2(-/-) mice, lacking expression of the laminin α2 subunit of the laminin-211 heterotrimer expressed by astrocytes and pericytes, have a defective BBB in which systemically circulated tracer leaks into the brain parenchyma. The Lama2(-/-) vascular endothelium had significant abnormalities, including altered integrity and composition of the endothelial basal lamina, inappropriate expression of embryonic vascular endothelial protein MECA32, substantially reduced pericyte coverage, and tight junction abnormalities. Additionally, astrocytic endfeet were hypertrophic and lacked appropriately polarized aquaporin4 channels. Laminin-211 appears to mediate these effects at least in part by dystroglycan receptor interactions, as preventing dystroglycan expression in neural cells led to a similar set of BBB abnormalities and gliovascular disturbances, which additionally included perturbed vascular endothelial glucose transporter-1 localization. These findings provide insight into the cell and molecular changes that occur in congenital muscular dystrophies caused by Lama2 mutations or inappropriate dystroglycan post-translational modifications, which have accompanying brain abnormalities, including seizures. Our results indicate a novel role for laminin-dystroglycan interactions in the cooperative integration of astrocytes, endothelial cells, and pericytes in regulating the BBB.
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40
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Astrocytic laminin regulates pericyte differentiation and maintains blood brain barrier integrity. Nat Commun 2014; 5:3413. [PMID: 24583950 PMCID: PMC3992931 DOI: 10.1038/ncomms4413] [Citation(s) in RCA: 244] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 02/10/2014] [Indexed: 02/06/2023] Open
Abstract
Blood brain barrier (BBB) breakdown is not only a consequence of but also contributes to many neurological disorders, including stroke and Alzheimer's disease. How the basement membrane (BM) contributes to the normal functioning of the BBB remains elusive. Here we use conditional knockout mice and an acute adenovirus-mediated knockdown model to show that lack of astrocytic laminin, a brain-specific BM component, induces BBB breakdown. Using functional blocking antibody and RNAi, we further demonstrate that astrocytic laminin, by binding to integrin α2 receptor, prevents pericyte differentiation from the BBB-stabilizing resting stage to the BBB-disrupting contractile stage, and thus maintains the integrity of BBB. Additionally, loss of astrocytic laminin decreases aquaporin-4 (AQP4) and tight junction protein expression. Altogether, we report a critical role for astrocytic laminin in BBB regulation and pericyte differentiation. These results indicate that astrocytic laminin maintains the integrity of BBB through, at least in part, regulation of pericyte differentiation.
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41
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Gao HL, Li C, Nabeka H, Shimokawa T, Kobayashi N, Saito S, Wang ZY, Cao YM, Matsuda S. Decrease in prosaposin in the Dystrophic mdx mouse brain. PLoS One 2013; 8:e80032. [PMID: 24244600 PMCID: PMC3828254 DOI: 10.1371/journal.pone.0080032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/27/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy caused by a mutation in the X-linked dystrophin gene induces metabolic and structural disorders in the brain. A lack of dystrophin in brain structures is involved in impaired cognitive function. Prosaposin (PS), a neurotrophic factor, is abundant in the choroid plexus and various brain regions. We investigated whether PS serves as a link between dystrophin loss and gross and/or ultrastructural brain abnormalities. METHODOLOGY/PRINCIPAL FINDINGS The distribution of PS in the brains of juvenile and adult mdx mice was investigated by immunochemistry, Western blotting, and in situ hybridization. Immunochemistry revealed lower levels of PS in the cytoplasm of neurons of the cerebral cortex, hippocampus, cerebellum, and choroid plexus in mdx mice. Western blotting confirmed that PS levels were lower in these brain regions in both juveniles and adults. Even with low PS production in the choroids plexus, there was no significant PS decrease in cerebrospinal fluid (CSF). In situ hybridization revealed that the primary form of PS mRNA in both normal and mdx mice was Pro+9, a secretory-type PS, and the hybridization signals for Pro+9 in the above-mentioned brain regions were weaker in mdx mice than in normal mice. We also investigated mitogen-activated protein kinase signalling. Stronger activation of ERK1/2 was observed in mdx mice, ERK1/2 activity was positively correlated with PS activity, and exogenous PS18 stimulated both p-ERK1/2 and PS in SH-SY5Y cells. CONCLUSIONS/SIGNIFICANCE Low levels of PS and its receptors suggest the participation of PS in some pathological changes in the brains of mdx mice.
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Affiliation(s)
- Hui-ling Gao
- Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Cheng Li
- Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
- Department of Immunology, China Medical University, Shenyang, China
| | - Hiroaki Nabeka
- Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
| | - Tetsuya Shimokawa
- Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
| | - Naoto Kobayashi
- Medical Education Center, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
| | - Shouichiro Saito
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Yanagido, Gifu, Japan
| | - Zhan-You Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Ya-ming Cao
- Department of Immunology, China Medical University, Shenyang, China
| | - Seiji Matsuda
- Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
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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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Vianello S, Yu H, Voisin V, Haddad H, He X, Foutz AS, Sebrié C, Gillet B, Roulot M, Fougerousse F, Perronnet C, Vaillend C, Matecki S, Escolar D, Bossi L, Israël M, de la Porte S. Arginine butyrate: a therapeutic candidate for Duchenne muscular dystrophy. FASEB J 2013; 27:2256-69. [PMID: 23430975 DOI: 10.1096/fj.12-215723] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
As a strategy to treat Duchenne muscular dystrophy, we used arginine butyrate, which combines two pharmacological activities: nitric oxide pathway activation, and histone deacetylase inhibition. Continuous intraperitoneal administration to dystrophin-deficient mdx mice resulted in a near 2-fold increase in utrophin (protein homologous to dystrophin) in skeletal muscle, heart, and brain, accompanied by an improvement of the dystrophic phenotype in both adult and newborn mice (45 and 70% decrease in creatine kinase level, respectively; 14% increase in tidal volume, 30% decrease in necrotic area in limb and 23% increase in isometric force). Intermittent administration, as performed in clinical trials, was then used to reduce the frequency of injections and to improve safety. This also enhanced utrophin level around 2-fold (EC50=284 mg/ml) and alleviated the dystrophic phenotype (inverted grid and grip test performance near to wild-type values, creatine kinase level decreased by 50%). Skin biopsies were used to monitor treatment efficacy, instead of invasive muscle biopsies, and this could be done a few days after the start of treatment. A 2-fold increase in utrophin expression was also shown in cultured human myotubes. In vivo and in vitro experiments demonstrated that the drug combination acts synergistically. Together, these data constitute a proof of principle of the beneficial effects of arginine butyrate on muscular dystrophy.
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Affiliation(s)
- Sara Vianello
- Neurobiologie & Développement-Unité Propres de Recherche 3294, Centre National de la Recherche Scientifique, Institut de Neurobiologie Alfred Fessard-FRC2118, Gif sur Yvette, France
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Lien CF, Mohanta SK, Frontczak-Baniewicz M, Swinny JD, Zablocka B, Górecki DC. Absence of glial α-dystrobrevin causes abnormalities of the blood-brain barrier and progressive brain edema. J Biol Chem 2012; 287:41374-85. [PMID: 23043099 DOI: 10.1074/jbc.m112.400044] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The blood-brain barrier (BBB) plays a key role in maintaining brain functionality. Although mammalian BBB is formed by endothelial cells, its function requires interactions between endotheliocytes and glia. To understand the molecular mechanisms involved in these interactions is currently a major challenge. We show here that α-dystrobrevin (α-DB), a protein contributing to dystrophin-associated protein scaffolds in astrocytic endfeet, is essential for the formation and functioning of BBB. The absence of α-DB in null brains resulted in abnormal brain capillary permeability, progressively escalating brain edema, and damage of the neurovascular unit. Analyses in situ and in two-dimensional and three-dimensional in vitro models of BBB containing α-DB-null astrocytes demonstrated these abnormalities to be associated with loss of aquaporin-4 water and Kir4.1 potassium channels from glial endfeet, formation of intracellular vacuoles in α-DB-null astrocytes, and defects of the astrocyte-endothelial interactions. These caused deregulation of tight junction proteins in the endothelia. Importantly, α-DB but not dystrophins showed continuous expression throughout development in BBB models. Thus, α-DB emerges as a central organizer of dystrophin-associated protein in glial endfeet and a rare example of a glial protein with a role in maintaining BBB function. Its abnormalities might therefore lead to BBB dysfunction.
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Affiliation(s)
- Chun Fu Lien
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
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Abstract
Astrocytes, the most prominent glial cell type in the brain, send specialized processes named endfeet, which enwrap blood vessels and express a large molecular repertoire dedicated to the physiology of the vascular system. One of the most striking properties of astrocyte endfeet is their enrichment in gap junction protein connexins 43 and 30 (Cx43 and Cx30) allowing for direct intercellular trafficking of ions and small signaling molecules through perivascular astroglial networks. The contribution of astroglial connexins to the physiology of the brain vascular system has never been addressed. Here, we show that Cx43 and Cx30 expression at the level of perivascular endfeet starts from postnatal days 2 and 12 and is fully mature at postnatal days 15 and 20, respectively, indicating that astroglial perivascular connectivity occurs and develops during postnatal blood-brain barrier (BBB) maturation. We demonstrate that mice lacking Cx30 and Cx43 in GFAP (glial fibrillary acidic protein)-positive cells display astrocyte endfeet edema and a partial loss of the astroglial water channel aquaporin-4 and β-dystroglycan, a transmembrane receptor anchoring astrocyte endfeet to the perivascular basal lamina. Furthermore, the absence of astroglial connexins weakens the BBB, which opens upon increased hydrostatic vascular pressure and shear stress. These results demonstrate that astroglial connexins are necessary to maintain BBB integrity.
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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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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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Altered presynaptic ultrastructure in excitatory hippocampal synapses of mice lacking dystrophins Dp427 or Dp71. Neurobiol Dis 2011; 43:134-41. [DOI: 10.1016/j.nbd.2011.02.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/20/2011] [Accepted: 02/27/2011] [Indexed: 11/13/2022] Open
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Duarri A, Lopez de Heredia M, Capdevila-Nortes X, Ridder MC, Montolio M, López-Hernández T, Boor I, Lien CF, Hagemann T, Messing A, Gorecki DC, Scheper GC, Martínez A, Nunes V, van der Knaap MS, Estévez R. Knockdown of MLC1 in primary astrocytes causes cell vacuolation: a MLC disease cell model. Neurobiol Dis 2011; 43:228-38. [PMID: 21440627 DOI: 10.1016/j.nbd.2011.03.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 03/07/2011] [Accepted: 03/14/2011] [Indexed: 10/18/2022] Open
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare type of leukodystrophy, in the majority of cases caused by mutations in the MLC1 gene. MRI from MLC patients shows diffuse cerebral white matter signal abnormality and swelling, with evidence of increased water content. Histopathology in a MLC patient shows vacuolation of myelin, which causes the cerebral white matter swelling. MLC1 protein is expressed in astrocytic processes that are part of blood- and cerebrospinal fluid-brain barriers. We aimed to create an astrocyte cell model of MLC disease. The characterization of rat astrocyte cultures revealed MLC1 localization in cell-cell contacts, which contains other proteins described typically in tight and adherent junctions. MLC1 localization in these contacts was demonstrated to depend on the actin cytoskeleton; it was not altered when disrupting the microtubule or the GFAP networks. In human tissues, MLC1 and the protein Zonula Occludens 1 (ZO-1), which is linked to the actin cytoskeleton, co-localized by EM immunostaining and were specifically co-immunoprecipitated. To create an MLC cell model, knockdown of MLC1 in primary astrocytes was performed. Reduction of MLC1 expression resulted in the appearance of intracellular vacuoles. This vacuolation was reversed by the co-expression of human MLC1. Re-examination of a human brain biopsy from an MLC patient revealed that vacuoles were also consistently present in astrocytic processes. Thus, vacuolation of astrocytes is also a hallmark of MLC disease.
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Affiliation(s)
- Anna Duarri
- Sección de Fisiología, Departamento de Ciencias Fisiológicas II, Universidad de Barcelona, Spain
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Kim JE, Yeo SI, Ryu HJ, Kim MJ, Kim DS, Jo SM, Kang TC. Astroglial loss and edema formation in the rat piriform cortex and hippocampus following pilocarpine-induced status epilepticus. J Comp Neurol 2011; 518:4612-28. [PMID: 20886625 DOI: 10.1002/cne.22482] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In the present study we analyzed aquaporin-4 (AQP4) immunoreactivity in the piriform cortex (PC) and the hippocampus of pilocarpine-induced rat epilepsy model to elucidate the roles of AQP4 in brain edema following status epilepticus (SE). In non-SE-induced animals, AQP4 immunoreactivity was diffusely detected in the PC and the hippocampus. AQP4 immunoreactivity was mainly observed in the endfeet of astrocytes. Following SE the AQP4-deleted area was clearly detected in the PC, not in the hippocampus. Decreases in dystrophin and α-syntrophin immunoreactivities were followed by reduction in AQP4 immunoreactivity. These alterations were accompanied by the development of vasogenic edema and the astroglial loss in the PC. In addition, acetazolamide (an AQP4 inhibitor) treatment exacerbated vasogenic edema and astroglial loss both in the PC and in the hippocampus. These findings suggest that SE may induce impairments of astroglial AQP4 functions via disruption of the dystrophin/α-syntrophin complex that worsen vasogenic edema. Subsequently, vasogenic edema results in extensive astroglial loss that may aggravate vasogenic edema.
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Affiliation(s)
- Ji-Eun Kim
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon, Kangwon-Do 200-702, South Korea
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