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Booler HS, Williams JL, Hopkinson M, Brown SC. Degree of Cajal-Retzius Cell Mislocalization Correlates with the Severity of Structural Brain Defects in Mouse Models of Dystroglycanopathy. Brain Pathol 2015; 26:465-78. [PMID: 26306834 DOI: 10.1111/bpa.12306] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 08/23/2015] [Indexed: 12/19/2022] Open
Abstract
The secondary dystroglycanopathies are characterized by the hypoglycosylation of alpha dystroglycan, and are associated with mutations in at least 18 genes that act on the glycosylation of this cell surface receptor rather than the Dag1 gene itself. At the severe end of the disease spectrum, there are substantial structural brain defects, the most striking of which is often cobblestone lissencephaly. The aim of this study was to determine the gene-specific aspects of the dystroglycanopathy brain phenotype through a detailed investigation of the structural brain defects present at birth in three mouse models of dystroglycanopathy-the FKRP(KD) , which has an 80% reduction in Fkrp transcript levels; the Pomgnt1null , which carries a deletion of exons 7-16 of the Pomgnt1 gene; and the Large(myd) mouse, which carries a deletion of exons 5-7 of the Large gene. We show a rostrocaudal and mediolateral gradient in the severity of brain lesions in FKRP(KD) , and to a lesser extent Pomgnt1null mice. Furthermore, the mislocalization of Cajal-Retzius cells is correlated with the gradient of these lesions and the severity of the brain phenotype in these models. Overall these observations implicate gene-specific differences in the pathogenesis of brain lesions in this group of disorders.
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Affiliation(s)
- Helen S Booler
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Josie L Williams
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Mark Hopkinson
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Susan C Brown
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
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Spontaneous malformations of the cerebellar vermis: Prevalence, inheritance, and relationship to lobule/fissure organization in the C57BL/6 lineage. Neuroscience 2015; 310:242-51. [PMID: 26383253 DOI: 10.1016/j.neuroscience.2015.09.025] [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: 07/21/2015] [Accepted: 09/09/2015] [Indexed: 11/22/2022]
Abstract
The complex neuronal circuitry of the cerebellum is embedded within its lamina, folia, and lobules, which together play an important role in sensory and motor function. Studies in mouse models have demonstrated that both cerebellar lamination and lobule/fissure development are under genetic control. The cerebellar vermis of C57BL/6 mice exhibits spontaneous malformations of neuronal migration of posterior lobules (VIII-IX; molecular layer heterotopia); however, the extent to which other inbred mice also exhibit these malformations is unknown. Using seven different inbred mouse strains and two first filial generation (F1) hybrids, we show that only the C57BL/6 strain exhibits heterotopia. Furthermore, we observed heterotopia in consomic and recombinant inbred strains. These data indicate that heterotopia formation is a weakly penetrant trait requiring homozygosity of one or more C57BL/6 alleles outside of chromosome 1 and the sex chromosomes. Additional morphological analyses showed no relationship between heterotopia formation and other features of lobule/fissure organization. These data are relevant toward understanding normal cerebellar development and disorders affecting cerebellar foliation and lamination.
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53
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Chemokine Signaling Controls Integrity of Radial Glial Scaffold in Developing Spinal Cord and Consequential Proper Position of Boundary Cap Cells. J Neurosci 2015; 35:9211-24. [PMID: 26085643 DOI: 10.1523/jneurosci.0156-15.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Radial glial cells are the neural progenitors of the developing CNS and have long radial processes that guide radially migrating neurons. The integrity of the radial glial scaffold, in particular proper adhesion between the endfeet of radial processes and the pial basement membrane (BM), is important for the cellular organization of the CNS, as indicated by evidence emerging from the developing cortex. However, the mechanisms underlying the maintenance of radial glial scaffold integrity during development, when the neuroepithelium rapidly expands, are still poorly understood. Here, we addressed this issue in the developing mouse spinal cord. We show that CXCR4, a receptor of chemokine CXCL12, is expressed in spinal cord radial glia. Conditional knock-out of Cxcr4 in radial glia caused disrupted radial glial scaffold with gaps at the pial endfeet layer and consequentially led to an invasion of boundary cap (BC) cells into the spinal cord. Because BC cells are PNS cells normally positioned at the incoming and outgoing axonal roots, their invasion into the spinal cord suggests a compromised CNS/PNS boundary in the absence of CXCL12/CXCR4 signaling. Both disrupted radial glial scaffold and invasion of BC cells into the CNS were also present in mice deficient in CXCR7, a second receptor of CXCL12. We further show that CXCL12 signaling promotes the radial glia adhesion to BM components and activates integrin β1 avidity. Our study unravels a novel molecular mechanism that deploys CXCL12/CXCR4/CXCR7 for the maintenance of radial glial scaffold integrity, which in turn safeguards the CNS/PNS boundary during spinal cord development.
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54
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Genetic Engineering of Dystroglycan in Animal Models of Muscular Dystrophy. BIOMED RESEARCH INTERNATIONAL 2015; 2015:635792. [PMID: 26380289 PMCID: PMC4561298 DOI: 10.1155/2015/635792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 03/11/2015] [Indexed: 01/24/2023]
Abstract
In skeletal muscle, dystroglycan (DG) is the central component of the dystrophin-glycoprotein complex (DGC), a multimeric protein complex that ensures a strong mechanical link between the extracellular matrix and the cytoskeleton. Several muscular dystrophies arise from mutations hitting most of the components of the DGC. Mutations within the DG gene (DAG1) have been recently associated with two forms of muscular dystrophy, one displaying a milder and one a more severe phenotype. This review focuses specifically on the animal (murine and others) model systems that have been developed with the aim of directly engineering DAG1 in order to study the DG function in skeletal muscle as well as in other tissues. In the last years, conditional animal models overcoming the embryonic lethality of the DG knock-out in mouse have been generated and helped clarifying the crucial role of DG in skeletal muscle, while an increasing number of studies on knock-in mice are aimed at understanding the contribution of single amino acids to the stability of DG and to the possible development of muscular dystrophy.
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55
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Nakagawa N, Yagi H, Kato K, Takematsu H, Oka S. Ectopic clustering of Cajal-Retzius and subplate cells is an initial pathological feature in Pomgnt2-knockout mice, a model of dystroglycanopathy. Sci Rep 2015; 5:11163. [PMID: 26060116 PMCID: PMC4461912 DOI: 10.1038/srep11163] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/18/2015] [Indexed: 11/09/2022] Open
Abstract
Aberrant glycosylation of dystroglycan causes congenital muscular dystrophies associated with cobblestone lissencephaly, classified as dystroglycanopathy. However, pathological features in the onset of brain malformations, including the precise timing and primary cause of the pial basement membrane disruption and abnormalities in the migration of pyramidal neurons, remain unexplored. Using the Pomgnt2-knockout (KO) mouse as a dystroglycanopathy model, we show that breaches of the pial basement membrane appeared at embryonic day 11.5, coinciding with the ectopic clustering of Cajal-Retzius cells and subplate neurons and prior to the migration onset of pyramidal neurons. Furthermore, in the Pomgnt2-KO cerebral cortex, preplate splitting failure likely occurred due to the aggregation of Cajal-Retzius and subplate cells, and migrating pyramidal neurons lost polarity and radial orientation. Our findings demonstrate the initial pathological events in dystroglycanopathy mice and contribute to our understanding of how dystroglycan dysfunction affects brain development and progresses to cobblestone lissencephaly.
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Affiliation(s)
- Naoki Nakagawa
- Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Hirokazu Yagi
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Koichi Kato
- 1] Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan [2] Okazaki Institute for Integrative Bioscience and Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama Myodaiji, Okazaki 444-8787, Japan
| | - Hiromu Takematsu
- Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Shogo Oka
- Department of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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Barkovich AJ, Dobyns WB, Guerrini R. Malformations of cortical development and epilepsy. Cold Spring Harb Perspect Med 2015; 5:a022392. [PMID: 25934463 DOI: 10.1101/cshperspect.a022392] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Malformations of cortical development (MCDs) are an important cause of epilepsy and an extremely interesting group of disorders from the perspective of brain development and its perturbations. Many new MCDs have been described in recent years as a result of improvements in imaging, genetic testing, and understanding of the effects of mutations on the ability of their protein products to correctly function within the molecular pathways by which the brain functions. In this review, most of the major MCDs are reviewed from a clinical, embryological, and genetic perspective. The most recent literature regarding clinical diagnosis, mechanisms of development, and future paths of research are discussed.
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Affiliation(s)
- A James Barkovich
- Department of Radiology and Biomedical Imaging, Neurology, Pediatrics, and Neurosurgery, University of California, San Francisco, San Francisco, California 94143-0628
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98101
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer, University of Florence, Florence 50139, Italy
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57
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Faissner A, Reinhard J. The extracellular matrix compartment of neural stem and glial progenitor cells. Glia 2015; 63:1330-49. [DOI: 10.1002/glia.22839] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/25/2015] [Accepted: 03/30/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology; Ruhr-University Bochum; Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology; Ruhr-University Bochum; Germany
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58
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Zhang X, Dong XH, Ma Y, Li LF, Wu H, Zhou M, Gu YH, Li GZ, Wang DS, Zhang XF, Mou J, Qi JP. Reduction of α-dystroglycan expression is correlated with poor prognosis in glioma. Tumour Biol 2014; 35:11621-9. [PMID: 25139094 DOI: 10.1007/s13277-014-2418-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/29/2014] [Indexed: 01/12/2023] Open
Abstract
Dystroglycan (DG), a multifunctional protein dimer of non-covalently linked α and β subunits, is best known as an adhesion and transduction molecule linking the cytoskeleton and intracellular signaling pathways to extracellular matrix proteins. Loss of DG binding, possibly by degradation or disturbed glycosylation, has been reported in a variety of cancers. DG is abundant at astroglial endfeet forming the blood-brain barrier (BBB) and glia limitans; so, we examined if loss of expression is associated with glioma. Expression levels of α-DG and β-DG were assessed by immunohistochemistry in a series of 78 glioma specimens to determine the relationship with tumor grade and possible prognostic significance. α-DG immunostaining was undetectable in 44 of 49 high-grade specimens (89.8%) compared to 15 of 29 low-grade specimens (51.72%) (P<0.05). Moreover, loss of α-DG expression was an independent predictor of shorter disease-free survival (DFS) (hazards ratio (HR) = 0.142, 95% confidence interval (CI) 0.033-0.611, P=0.0088). Reduced expression of both α-DG and β-DG was also a powerful negative prognostic factor for DFS (HR=2.556, 95% CI 1.403-4.654, P=0.0022) and overall survival (OS) (HR=2.193, 95% CI 1.031-4.666, P=0.0414). Lack of α-DG immunoreactivity is more frequent in high-grade glioma and is an independent predictor of poor clinical outcome. Similarly, lack of both α-DG and β-DG immunoreactivity is a strong independent predictor of clinical outcome.
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Affiliation(s)
- Xin Zhang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, No.23 Youzheng Street, NanGang District, Harbin, 150001, China
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59
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Sun T, Hevner RF. Growth and folding of the mammalian cerebral cortex: from molecules to malformations. Nat Rev Neurosci 2014; 15:217-32. [PMID: 24646670 DOI: 10.1038/nrn3707] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The size and extent of folding of the mammalian cerebral cortex are important factors that influence a species' cognitive abilities and sensorimotor skills. Studies in various animal models and in humans have provided insight into the mechanisms that regulate cortical growth and folding. Both protein-coding genes and microRNAs control cortical size, and recent progress in characterizing basal progenitor cells and the genes that regulate their proliferation has contributed to our understanding of cortical folding. Neurological disorders linked to disruptions in cortical growth and folding have been associated with novel neurogenetic mechanisms and aberrant signalling pathways, and these findings have changed concepts of brain evolution and may lead to new medical treatments for certain disorders.
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Affiliation(s)
- Tao Sun
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, BOX 60, New York, New York 10065, USA
| | - Robert F Hevner
- Department of Neurological Surgery and Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98101, USA
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60
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Theocharidis U, Long K, ffrench-Constant C, Faissner A. Regulation of the neural stem cell compartment by extracellular matrix constituents. PROGRESS IN BRAIN RESEARCH 2014; 214:3-28. [DOI: 10.1016/b978-0-444-63486-3.00001-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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61
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Ramos RL, Siu NY, Brunken WJ, Yee KT, Gabel LA, Van Dine SE, Hoplight BJ. Cellular and Axonal Constituents of Neocortical Molecular Layer Heterotopia. Dev Neurosci 2014; 36:477-89. [DOI: 10.1159/000365100] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/05/2014] [Indexed: 11/19/2022] Open
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Nguyen H, Ostendorf AP, Satz JS, Westra S, Ross-Barta SE, Campbell KP, Moore SA. Glial scaffold required for cerebellar granule cell migration is dependent on dystroglycan function as a receptor for basement membrane proteins. Acta Neuropathol Commun 2013; 1:58. [PMID: 24252195 PMCID: PMC3893534 DOI: 10.1186/2051-5960-1-58] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 09/02/2013] [Indexed: 11/18/2022] Open
Abstract
Background Cobblestone lissencephaly is a severe neuronal migration disorder associated with congenital muscular dystrophies (CMD) such as Walker-Warburg syndrome, muscle-eye-brain disease, and Fukuyama-type CMD. In these severe forms of dystroglycanopathy, the muscular dystrophy and other tissue pathology is caused by mutations in genes involved in O-linked glycosylation of alpha-dystroglycan. While cerebellar dysplasia is a common feature of dystroglycanopathy, its pathogenesis has not been thoroughly investigated. Results Here we evaluate the role of dystroglycan during cerebellar development. Brain-selective deletion of dystroglycan does not affect overall cerebellar growth, yet causes malformations associated with glia limitans disruptions and granule cell heterotopia that recapitulate phenotypes found in dystroglycanopathy patients. Cerebellar pathology in these mice is not evident until birth even though dystroglycan is lost during the second week of embryogenesis. The severity and spatial distribution of glia limitans disruption, Bergmann glia disorganization, and heterotopia exacerbate during postnatal development. Astrogliosis becomes prominent at these same sites by the time cerebellar development is complete. Interestingly, there is spatial heterogeneity in the glia limitans and granule neuron migration defects that spares the tips of lobules IV-V and VI. Conclusions The full spectrum of developmental pathology is caused by loss of dystroglycan from Bergmann glia, as neither granule cell- nor Purkinje cell-specific deletion of dystroglycan results in similar pathology. These data illustrate the importance of dystroglycan function in radial/Bergmann glia, not neurons, for normal cerebellar histogenesis. The spatial heterogeneity of pathology suggests that the dependence on dystroglycan is not uniform.
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63
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Eto K, Sakai N, Shimada S, Shioda M, Ishigaki K, Hamada Y, Shinpo M, Azuma J, Tominaga K, Shimojima K, Ozono K, Osawa M, Yamamoto T. Microdeletions of 3p21.31 characterized by developmental delay, distinctive features, elevated serum creatine kinase levels, and white matter involvement. Am J Med Genet A 2013; 161A:3049-56. [DOI: 10.1002/ajmg.a.36156] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 06/27/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Kaoru Eto
- Department of Pediatrics; Tokyo Women's Medical University; Tokyo Japan
| | - Norio Sakai
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Shino Shimada
- Department of Pediatrics; Tokyo Women's Medical University; Tokyo Japan
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Mutsuki Shioda
- Department of Pediatrics; Tokyo Women's Medical University; Tokyo Japan
| | - Keiko Ishigaki
- Department of Pediatrics; Tokyo Women's Medical University; Tokyo Japan
| | - Yusuke Hamada
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Michiko Shinpo
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Junji Azuma
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Koji Tominaga
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Keiko Shimojima
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Keiichi Ozono
- Department of Pediatrics; Osaka University Graduate School of Medicine; Suita Japan
| | - Makiko Osawa
- Department of Pediatrics; Tokyo Women's Medical University; Tokyo Japan
| | - Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
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