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Marinowic DR, Majolo F, Zanirati GG, Plentz I, Neto EP, Palmini ALF, Machado DC, Da Costa JC. Analysis of genes involved in cell proliferation, adhesion, and control of apoptosis during embryonic neurogenesis in Induced Pluripotent Stem Cells (iPSCs) from patients with Focal Cortical Dysplasia. Brain Res Bull 2019; 155:112-118. [PMID: 31816405 DOI: 10.1016/j.brainresbull.2019.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 10/25/2022]
Abstract
Focal cortical dysplasia (FCD) is a malformation of cortical development which is strongly associated with drug-refractory epilepsy. Certain studies have demonstrated an increase in mTOR signaling in patients with FCD on the basis of observation of phosphorylated molecules. The aim of the present study was to verify the differences in genes involved in cell proliferation, adhesion, and control of apoptosis during embryonic neurogenesis in iPSCs derived from the Focal Cortical Dysplasia. Fibroblasts were obtained from the skin biopsies of patients with FCD (n = 2) and controls (n = 2). iPSCs were generated by exposing the fibroblasts to viral vectors that contained the Yamanaka factors (OCT4, SOX2, KLF4, and c-MYC genes) responsible for promoving cell reprogramation. The fibroblasts and iPSCs were tested during different phases of neurodifferentiation for migration capacity and expression of the genes involved in the PI3K pathway. Fibroblasts of patients with FCD migrated with greater intensity during the first two time points of analyses. iPSCs did not exhibit any difference in cell migration between the groups. Fibroblasts, brain tissue, and iPSCs of the patients with FCD exhibited a significant reduction in the relative expression values of 4EBP-1. During neurodevelopment, the iPSCs from patients with FCD exhibited a reduction in the expression of cIAP-1, cIAP-2, PI3K, β-Catenin and 4EBP-1 gene. We suggest that the differences observed in the migration potential of adult cells and in the gene expression related to the fundamental processes involved in normal brain development during the neurodifferentiation process might be associated with cortical alteration in the patients with FCD.
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Affiliation(s)
- Daniel Rodrigo Marinowic
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Fernanda Majolo
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Gabriele Goulart Zanirati
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine, Pediatrics and Child Health, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Ismael Plentz
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine, Pediatrics and Child Health, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Eliseu Paglioli Neto
- School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Epilepsy Surgery Program of São Lucas Hospital of Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - André Luís Fernandes Palmini
- School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Epilepsy Surgery Program of São Lucas Hospital of Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Denise Cantarelli Machado
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Jaderson Costa Da Costa
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Medicine, Pediatrics and Child Health, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
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García-Rincón D, Díaz-Alonso J, Paraíso-Luna J, Ortega Z, Aguareles J, de Salas-Quiroga A, Jou C, de Prada I, Martínez-Cerdeño V, Aronica E, Guzmán M, Pérez-Jiménez MÁ, Galve-Roperh I. Contribution of Altered Endocannabinoid System to Overactive mTORC1 Signaling in Focal Cortical Dysplasia. Front Pharmacol 2019; 9:1508. [PMID: 30687088 PMCID: PMC6334222 DOI: 10.3389/fphar.2018.01508] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/10/2018] [Indexed: 02/05/2023] Open
Abstract
Alterations of the PI3K/Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling pathway are causally involved in a subset of malformations of cortical development (MCDs) ranging from focal cortical dysplasia (FCD) to hemimegalencephaly and megalencephaly. These MCDs represent a frequent cause of refractory pediatric epilepsy. The endocannabinoid system -especially cannabinoid CB1 receptor- exerts a neurodevelopmental regulatory role at least in part via activation of mTORC1 signaling. Therefore, we sought to characterize the possible contribution of endocannabinoid system signaling to FCD. Confocal microscopy characterization of the CB1 receptor expression and mTORC1 activation was conducted in FCD Type II resection samples. FCD samples were subjected to single nucleotide polymorphism screening for endocannabinoid system elements, as well as CB1 receptor gene sequencing. Cannabinoid CB1 receptor levels were increased in FCD with overactive mTORC1 signaling. CB1 receptors were enriched in phospho-S6-positive cells including balloon cells (BCs) that co-express aberrant markers of undifferentiated cells and dysplastic neurons. Pharmacological regulation of CB1 receptors and the mTORC1 pathway was performed in fresh FCD-derived organotypic cultures. HU-210-evoked activation of CB1 receptors was unable to further activate mTORC1 signaling, whereas CB1 receptor blockade with rimonabant attenuated mTORC1 overactivation. Alterations of the endocannabinoid system may thus contribute to FCD pathological features, and blockade of cannabinoid signaling might be a new therapeutic intervention in FCD.
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Affiliation(s)
- Daniel García-Rincón
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Javier Díaz-Alonso
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Juan Paraíso-Luna
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Zaira Ortega
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - José Aguareles
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Adán de Salas-Quiroga
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Cristina Jou
- Departamento de Anatomía Patológica, Hospital Sant Joan de Déu, Barcelona, Spain
| | | | - Verónica Martínez-Cerdeño
- Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children of Northern California and Department of Pathology and Laboratory Medicine, School of Medicine, University of California, Davis, Sacramento, CA, United States
| | - Eleonora Aronica
- Amsterdam UMC, Department of (Neuro)Pathology, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, Netherlands.,Stichting Epilepsie Instellingen Nederland, Heemstede, Netherlands
| | - Manuel Guzmán
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | | | - Ismael Galve-Roperh
- Instituto Ramón y Cajal de Investigación Sanitaria, Department of Biochemistry and Molecular Biology and Instituto Universitario de Investigación Neuroquímica, Complutense University, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
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3
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Donkels C, Pfeifer D, Janz P, Huber S, Nakagawa J, Prinz M, Schulze-Bonhage A, Weyerbrock A, Zentner J, Haas CA. Whole Transcriptome Screening Reveals Myelination Deficits in Dysplastic Human Temporal Neocortex. Cereb Cortex 2018; 27:1558-1572. [PMID: 26796214 DOI: 10.1093/cercor/bhv346] [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] [Indexed: 01/01/2023] Open
Abstract
Focal cortical dysplasias (FCDs) are local malformations of the human neocortex with strong epileptogenic potential. To investigate the underlying pathomechanisms, we performed a whole human transcriptome screening to compare the gene expression pattern of dysplastic versus nondysplastic temporal neocortex. Tissue obtained from FCD IIIa cases (mean age 20.5 years) who had undergone surgical treatment, due to intractable epilepsy, was compared with nondysplastic specimens (mean age 19.9 years) by means of Affymetrix arrays covering 28 869 genes. We found 211 differentially expressed genes (DEX) among which mainly genes important for oligodendrocyte differentiation and myelination were downregulated in FCD IIIa. These findings were confirmed as functionally important by Database for Annotation, Visualization, and Integrated Discovery (DAVID) analysis. The reduced expression of myelin-associated transcripts was confirmed for FCD Ia, IIa, and IIIa by real-time RT-qPCR. In addition, we found that the density of myelin basic protein mRNA-expressing oligodendrocytes and of 2',3'-cyclic nucleotide 3'-phosphodiesterase-positive myelin fibers was significantly reduced in dysplastic cortex. Moreover, high-resolution confocal imaging and 3D reconstruction revealed that the myelin fiber network was severely disorganized in dysplastic neocortex, indicating a disturbance of myelin sheath formation and maintenance in FCD.
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Affiliation(s)
- Catharina Donkels
- Experimental Epilepsy Research, Department of Neurosurgery.,Faculty of Biology
| | - Dietmar Pfeifer
- Department of Hematology, Oncology and Stem Cell Transplantation
| | - Philipp Janz
- Experimental Epilepsy Research, Department of Neurosurgery.,Faculty of Biology
| | - Susanne Huber
- Experimental Epilepsy Research, Department of Neurosurgery
| | - Julia Nakagawa
- Experimental Epilepsy Research, Department of Neurosurgery.,Department of Neurosurgery
| | - Marco Prinz
- Institute of Neuropathology.,Center for Biological Signalling Studies
| | - Andreas Schulze-Bonhage
- Epilepsy Center Freiburg, University Medical Center Freiburg, Freiburg, Germany.,BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | | | | | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery.,Bernstein Center Freiburg.,BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
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4
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Somatic mutations rather than viral infection classify focal cortical dysplasia type II as mTORopathy. Curr Opin Neurol 2018; 29:388-95. [PMID: 26840044 DOI: 10.1097/wco.0000000000000303] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Genetic studies in focal cortical dysplasia type II (FCD II) provided ample evidence for somatic mutations in genes associated with the mammalian target of rapamycin (mTOR) pathway. Interestingly, the mTOR pathway can also be activated by the E6 oncogene of human papilloma viruses, and available data in FCD II remain controversial. We review and discuss the contradicting etiologies. RECENT FINDINGS The neuroembryologic basis of cortical development and timing of a somatic mutation occurring in proliferating neuroblasts can mechanistically link mTORopathies. When a somatic mutation occurs in proliferating neuroblasts at an early stage of their anticipated total number of 33 mitotic cell cycles, large hemispheric lesions will develop from their affected progeny. Somatic mutations occurring at later periods of neuroblast expansion will result in circumscribed and small FCD II. Recently published data did not support evidence for viral infection in FCD II. SUMMARY Genetic and histopathological data rather than viral infection classify FCD II into the spectrum of mTORopathies. Size and extent of the resulting cerebral lesion can be well explained by timing of somatic mutations during cortical development.
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Gao K, Zhang Y, Zhang L, Kong W, Xie H, Wang J, Wu Y, Wu X, Liu X, Zhang Y, Zhang F, Yu ACH, Jiang Y. Large De Novo Microdeletion in Epilepsy with Intellectual and Developmental Disabilities, with a Systems Biology Analysis. ADVANCES IN NEUROBIOLOGY 2018; 21:247-266. [DOI: 10.1007/978-3-319-94593-4_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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6
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Hanai S, Sukigara S, Dai H, Owa T, Horike SI, Otsuki T, Saito T, Nakagawa E, Ikegaya N, Kaido T, Sato N, Takahashi A, Sugai K, Saito Y, Sasaki M, Hoshino M, Goto YI, Koizumi S, Itoh M. Pathologic Active mTOR Mutation in Brain Malformation with Intractable Epilepsy Leads to Cell-Autonomous Migration Delay. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:1177-1185. [PMID: 28427592 DOI: 10.1016/j.ajpath.2017.01.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/19/2017] [Indexed: 01/08/2023]
Abstract
The activation of phosphatidylinositol 3-kinase-AKTs-mammalian target of rapamycin cell signaling pathway leads to cell overgrowth and abnormal migration and results in various types of cortical malformations, such as hemimegalencephaly (HME), focal cortical dysplasia, and tuberous sclerosis complex. However, the pathomechanism underlying abnormal cell migration remains unknown. With the use of fetal mouse brain, we performed causative gene analysis of the resected brain tissues from a patient with HME and investigated the pathogenesis. We obtained a novel somatic mutation of the MTOR gene, having approximately 11% and 7% mutation frequency in the resected brain tissues. Moreover, we revealed that the MTOR mutation resulted in hyperphosphorylation of its downstream molecules, S6 and 4E-binding protein 1, and delayed cell migration on the radial glial fiber and did not affect other cells. We suspect cell-autonomous migration arrest on the radial glial foot by the active MTOR mutation and offer potential explanations for why this may lead to cortical malformations such as HME.
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Affiliation(s)
- Sae Hanai
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Kodaira, Japan
| | - Sayuri Sukigara
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Kodaira, Japan
| | - Hongmei Dai
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Kodaira, Japan
| | - Tomoo Owa
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, Kodaira, Japan
| | - Shin-Ichi Horike
- Division of Functional Genomics, Advanced Science Research Center Kanazawa University, Kanazawa, Japan
| | - Taisuke Otsuki
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Neurosurgery, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Takashi Saito
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Child Neurology, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Eiji Nakagawa
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Child Neurology, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Naoki Ikegaya
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Neurosurgery, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Takanobu Kaido
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Neurosurgery, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Noriko Sato
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Radiology, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Akio Takahashi
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Neurosurgery, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Kenji Sugai
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Child Neurology, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Yuko Saito
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Laboratory Medicine, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Masayuki Sasaki
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Child Neurology, Hospital of National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Mikio Hoshino
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, Kodaira, Japan
| | - Yu-Ichi Goto
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Kodaira, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Japan
| | - Masayuki Itoh
- Epilepsy Center, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Japan; Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Kodaira, Japan.
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Marinowic DR, Majolo F, Sebben AD, Da Silva VD, Lopes TG, Paglioli E, Palmini A, Machado DC, Da Costa JC. Induced pluripotent stem cells from patients with focal cortical dysplasia and refractory epilepsy. Mol Med Rep 2017; 15:2049-2056. [PMID: 28260047 PMCID: PMC5364982 DOI: 10.3892/mmr.2017.6264] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/16/2017] [Indexed: 01/12/2023] Open
Abstract
Focal cortical dysplasia (FCD) is caused by numerous alterations, which can be divided into abnormalities of the cortical architecture and cytological variations; however, the exact etiology of FCD remains unknown. The generation of induced pluripotent stem cells (iPSCs) from the cells of patients with neurological diseases, and their subsequent tissue‑specific differentiation, serves as an invaluable source for testing and studying the initial development and subsequent progression of diseases associated with the central nervous system. A total of 2 patients demonstrating seizures refractory to drug treatment, characterized as FCD Type IIb, were enrolled in the present study. Fibroblasts were isolated from residual skin fragments obtained from surgical treatment and from brain samples obtained during surgical resection. iPSCs were generated following exposure of fibroblasts to viral vectors containing POU class 5 homeobox 1 (OCT4), sex determining region Y‑box 2 (SOX2), Kruppel‑like factor 4 and c‑MYC genes, and were characterized by immunohistochemical staining for the pluripotent markers homeobox protein NANOG, SOX2, OCT4, TRA1‑60 and TRA1‑81. The brain samples were tested with antibodies against protein kinase B (AKT), phosphorylated‑AKT, mechanistic target of rapamycin (mTOR) and phosphorylated‑mTOR. Analysis of the AKT/mTOR pathway revealed a statistically significant difference between the cerebral tissues of the two patients, which were of different ages (45 and 12 years old). Clones with the morphological features of embryonic cells were detected on the 13th day and were characterized following three subcultures. The positive staining characteristics of the embryonic cells confirmed the successful generation of iPSCs derived from the patients' fibroblasts. Therefore, the present study presents a method to obtain a useful cellular source that may help to understand embryonic brain development associated with FCD.
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Affiliation(s)
- Daniel Rodrigo Marinowic
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Institute for Biomedical Research, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Fernanda Majolo
- Institute for Biomedical Research, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Alessandra Deise Sebben
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Institute for Biomedical Research, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Vinicius Duval Da Silva
- Laboratory of Pathological Anatomy, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Postgraduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Tiago Giuliani Lopes
- Laboratory of Pathological Anatomy, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Eliseu Paglioli
- Epilepsy Surgery Program, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - André Palmini
- Postgraduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Epilepsy Surgery Program, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Denise Cantarelli Machado
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Institute for Biomedical Research, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Laboratory of Pathological Anatomy, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
| | - Jaderson Costa Da Costa
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
- Postgraduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil
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Zheng DH, Guo W, Sun FJ, Xu GZ, Zang ZL, Shu HF, Yang H. Expression of TRPC6 and BDNF in Cortical Lesions From Patients With Focal Cortical Dysplasia. J Neuropathol Exp Neurol 2016; 75:718-730. [PMID: 27288906 PMCID: PMC4940447 DOI: 10.1093/jnen/nlw044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 01/15/2023] Open
Abstract
Focal cortical dysplasia (FCD) likely results from abnormal migration of neural progenitor cells originating from the subventricular zone. To elucidate the roles in molecules that are involved in neural migration pathway abnormalities in FCDs, we investigated the expression patterns of transient receptor potential canonical channel 6 (TRPC6) and brain-derived neurotrophic factor (BDNF) in cortical lesions from FCD patients and in samples of normal control cortex. TRPC6 and BDNF mRNA and protein levels were increased in FCD lesions. By immunohistochemistry, they were strongly expressed in microcolumns, heterotopic neurons, dysmorphic neurons, and balloon cells (BCs). Colocalization assays revealed that most of the misshapen TRPC6-positive or heterotopic cells had a neuronal lineage with the exception of TRPC6-positive FCDiib patient BCs, which had both neuronal and glial features. Most TRPC6-positive cells were glutamatergic neurons. There was also greater expression of calmodulin-dependent kinase IV (CaMKIV), the downstream factor of TRPC6, in FCD lesions, suggesting that TRPC6 expression promoted dendritic growth and the development of dendritic spines and excitatory synapses via the CaMKIV-CREB pathway in FCD. Thus, overexpression of BDNF and TRPC6 and activation of the TRPC6 signal transduction pathway in cortical lesions of FCD patients may contribute to FC pathogenesis and epileptogenesis.
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Affiliation(s)
- Da-Hai Zheng
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Wei Guo
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Fei-Ji Sun
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Guang-Zhen Xu
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Zhen-Le Zang
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Hai-Feng Shu
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China
| | - Hui Yang
- From the Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University (D-HZ, F-J, G-ZX, Z-LZ, H-FS, HY), Chongqing, China; Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University(WG), Xi'an, Shanxi, China; Department of Neurosurgery, General Hospital of Chengdu Military Region(H-FS), Chengdu, Sichuan, China.
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Nunes ML, Carlini CR, Marinowic D, Neto FK, Fiori HH, Scotta MC, Zanella PLÁ, Soder RB, da Costa JC. Microcephaly and Zika virus: a clinical and epidemiological analysis of the current outbreak in Brazil. J Pediatr (Rio J) 2016; 92:230-40. [PMID: 27049675 DOI: 10.1016/j.jped.2016.02.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE This study aimed to critically review the literature available regarding the Zika virus outbreak in Brazil and its possible association with microcephaly cases. SOURCES Experts from Instituto do Cérebro do Rio Grande do Sul performed a critical (nonsystematic) literature review regarding different aspects of the Zika virus outbreak in Brazil, such as transmission, epidemiology, diagnostic criteria, and its possible association with the increase of microcephaly reports. The PubMed search using the key word "Zika virus" in February 2016 yielded 151 articles. The manuscripts were reviewed, as well as all publications/guidelines from the Brazilian Ministry of Health, World Health Organization and Centers for Disease Control and Prevention (CDC - United States). SUMMARY OF FINDINGS Epidemiological data suggest a temporal association between the increased number of microcephaly notifications in Brazil and outbreak of Zika virus, primarily in the Brazil's Northeast. It has been previously documented that many different viruses might cause congenital acquired microcephaly. Still there is no consensus on the best curve to measure cephalic circumference, specifically in preterm neonates. Conflicting opinions regarding the diagnosis of microcephaly (below 2 or 3 standard deviations) that should be used for the notifications were also found in the literature. CONCLUSION The development of diagnostic techniques that confirm a cause-effect association and studies regarding the physiopathology of the central nervous system impairment should be prioritized. It is also necessary to strictly define the criteria for the diagnosis of microcephaly to identify cases that should undergo an etiological investigation.
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Affiliation(s)
- Magda Lahorgue Nunes
- School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil.
| | - Celia Regina Carlini
- Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil; Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil
| | - Daniel Marinowic
- Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil; Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil
| | - Felipe Kalil Neto
- Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil; Post-Graduate Program in Pediatrics and Child Health, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Humberto Holmer Fiori
- School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil
| | - Marcelo Comerlato Scotta
- Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil; Department of Pediatrics, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Pedro Luis Ávila Zanella
- School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil
| | - Ricardo Bernardi Soder
- Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil; Department of Diagnostic Methods, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Jaderson Costa da Costa
- School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil
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10
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Nunes ML, Carlini CR, Marinowic D, Neto FK, Fiori HH, Scotta MC, Zanella PLÁ, Soder RB, da Costa JC. Microcephaly and Zika virus: a clinical and epidemiological analysis of the current outbreak in Brazil. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2016. [DOI: 10.1016/j.jpedp.2016.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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11
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Kim SH, Millichap JJ, Koh S. Brain Inflammation in an Infant With Hemimegalencephaly, Escalating Seizures, and Epileptic Encephalopathy. Child Neurol Open 2016; 3:2329048X16633629. [PMID: 28503608 PMCID: PMC5417290 DOI: 10.1177/2329048x16633629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/19/2016] [Accepted: 01/23/2016] [Indexed: 11/17/2022] Open
Abstract
Hemimegalencephaly, a congenital brain malformation typically characterized by enlargement of one hemisphere, is frequently associated with intractable epilepsy. The authors report a case of a 12-month-old girl with hemimegalencephaly who underwent semiurgent hemispherectomy because of rapidly escalating seizures, arrested development, and associated encephalopathy. The brain tissue was examined and evaluated for neuroinflammation. Immunohistochemical analysis of the brain tissue revealed the presence of abundant activated CD68-positive microglia and reactive astrogliosis. Detection of active inflammatory changes in the brain of a patient with hemimegalencephaly complicated by intractable epilepsy suggests a potential role of ongoing brain inflammation in seizure exacerbation and epileptic encephalopathy.
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Affiliation(s)
- Se Hee Kim
- Epilepsy Center, Ann & Robert H. Lurie Children's Hospital of Chicago, Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - John J Millichap
- Epilepsy Center, Ann & Robert H. Lurie Children's Hospital of Chicago, Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sookyong Koh
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
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12
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Mühlebner A, Iyer AM, van Scheppingen J, Anink JJ, Jansen FE, Veersema TJ, Braun KP, Spliet WGM, van Hecke W, Söylemezoğlu F, Feucht M, Krsek P, Zamecnik J, Bien CG, Polster T, Coras R, Blümcke I, Aronica E. Specific pattern of maturation and differentiation in the formation of cortical tubers in tuberous sclerosis omplex (TSC): evidence from layer-specific marker expression. J Neurodev Disord 2016; 8:9. [PMID: 27042238 PMCID: PMC4818922 DOI: 10.1186/s11689-016-9142-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/08/2016] [Indexed: 03/12/2023] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is a multisystem disorder that results from mutations in the TSC1 or TSC2 genes, leading to constitutive activation of the mammalian target of rapamycin (mTOR) signaling pathway. Cortical tubers represent typical lesions of the central nervous system (CNS) in TSC. The pattern of cortical layering disruption observed in brain tissue of TSC patients is not yet fully understood, and little is known about the origin and phenotype of individual abnormal cell types recognized in tubers. METHODS In the present study, we aimed to characterize dysmorphic neurons (DNs) and giant cells (GCs) of cortical tubers using neocortical layer-specific markers (NeuN, SMI32, Tbr1, Satb2, Cux2, ER81, and RORβ) and to compare the features with the histo-morphologically similar focal cortical dysplasia (FCD) type IIb. We studied a cohort of nine surgically resected cortical tubers, five FCD type IIb, and four control samples using immunohistochemistry and in situ hybridization. RESULTS Cortical tuber displayed a prominent cell loss in all cortical layers. Moreover, we observed altered proportions of layer-specific markers within the dysplastic region. DNs, in both tubers and FCD type IIb, were found positive for different cortical layer markers, regardless of their laminar location, and their immunophenotype resembles that of cortical projection neurons. CONCLUSIONS These findings demonstrate that, similar to FCD type IIb, cortical layering is markedly disturbed in cortical tubers of TSC patients. Distribution of these disturbances is comparable in all tubers and suggests a dysmaturation affecting early and late migratory patterns, with a more severe impairment of the late stage of maturation.
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Affiliation(s)
- Angelika Mühlebner
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands ; Department of Pediatrics, Medical University Vienna, Vienna, Austria
| | - Anand M Iyer
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Jasper J Anink
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands
| | - Floor E Jansen
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tim J Veersema
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kees P Braun
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wim van Hecke
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Figen Söylemezoğlu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Martha Feucht
- Department of Pediatrics, Medical University Vienna, Vienna, Austria
| | - Pavel Krsek
- Department of Neurology, Charles University, 2nd Faculty of Medicine, Motol University Hospital, Prague, Czech Republic
| | - Josef Zamecnik
- Department of Pathology and Molecular Medicine, Charles University, 2nd Faculty of Medicine, Motol University Hospital, Prague, Czech Republic
| | | | - Tilman Polster
- Epilepsy Centre Bethel, Krankenhaus Mara, Bielefeld, Germany
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands ; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands ; Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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13
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Roy A, Skibo J, Kalume F, Ni J, Rankin S, Lu Y, Dobyns WB, Mills GB, Zhao JJ, Baker SJ, Millen KJ. Mouse models of human PIK3CA-related brain overgrowth have acutely treatable epilepsy. eLife 2015; 4. [PMID: 26633882 PMCID: PMC4744197 DOI: 10.7554/elife.12703] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/26/2015] [Indexed: 12/12/2022] Open
Abstract
Mutations in the catalytic subunit of phosphoinositide 3-kinase (PIK3CA) and other PI3K-AKT pathway components have been associated with cancer and a wide spectrum of brain and body overgrowth. In the brain, the phenotypic spectrum of PIK3CA-related segmental overgrowth includes bilateral dysplastic megalencephaly, hemimegalencephaly and focal cortical dysplasia, the most common cause of intractable pediatric epilepsy. We generated mouse models expressing the most common activating Pik3ca mutations (H1047R and E545K) in developing neural progenitors. These accurately recapitulate all the key human pathological features including brain enlargement, cortical malformation, hydrocephalus and epilepsy, with phenotypic severity dependent on the mutant allele and its time of activation. Underlying mechanisms include increased proliferation, cell size and altered white matter. Notably, we demonstrate that acute 1 hr-suppression of PI3K signaling despite the ongoing presence of dysplasia has dramatic anti-epileptic benefit. Thus PI3K inhibitors offer a promising new avenue for effective anti-epileptic therapy for intractable pediatric epilepsy patients. DOI:http://dx.doi.org/10.7554/eLife.12703.001 An enzyme called PI3K is involved in a major signaling pathway that controls cell growth. Mutations in this pathway have devastating consequences. When such mutations happen in adults, they can lead to cancer. Mutations that occur in embryos can cause major developmental birth defects, including abnormally large brains. After birth, these developmental problems can cause intellectual disabilities, autism and epilepsy. Children with this kind of epilepsy often do not respond to currently available seizure medications. There are several outstanding questions that if answered could help efforts to develop treatments for children with brain growth disorders. Firstly, how do the developmental abnormalities happen? Do the abnormalities themselves cause epilepsy? And can drugs that target this pathway, and are already in clinical trials for cancer, control seizures? Now, Roy et al. have made mouse models of these human developmental brain disorders and used them to answer these questions. The mice were genetically engineered to have various mutations in the gene that encodes the catalytic subunit of the PI3K enzyme. The mutations were the same as those found in people with brain overgrowth disorders, and were activated only in the developing brain of the mice. These mutations caused enlarged brain size, fluid accumulation in the brain, brain malformations and epilepsy in developing mice – thus mimicking the human birth defects. The severity of these symptoms depended on the specific mutation and when the mutant genes were turned on during development. Next, Roy et al. studied these mice to see if the seizures could be treated using a drug, that has already been developed for brain cancer. This drug specifically targets and reduces the activity of PI3K. Adult mutant mice with brain malformations were treated for just one hour; this dramatically reduced their seizures. These experiments prove that seizures associated with this kind of brain overgrowth disorder are driven by ongoing abnormal PI3K activity and can be treated even when underlying brain abnormalities persist. Roy et al. suggest that drugs targeting PI3K might help treat seizures in children with these brain overgrowth disorders. DOI:http://dx.doi.org/10.7554/eLife.12703.002
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Affiliation(s)
- Achira Roy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Jonathan Skibo
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Franck Kalume
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Jing Ni
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, United States
| | - Sherri Rankin
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, United States
| | - Yiling Lu
- The University of Texas MD Anderson Cancer Center, Houston, United States
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Gordon B Mills
- The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Jean J Zhao
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, United States
| | - Suzanne J Baker
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, United States
| | - Kathleen J Millen
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
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Abdijadid S, Mathern GW, Levine MS, Cepeda C. Basic mechanisms of epileptogenesis in pediatric cortical dysplasia. CNS Neurosci Ther 2014; 21:92-103. [PMID: 25404064 DOI: 10.1111/cns.12345] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/29/2014] [Accepted: 10/03/2014] [Indexed: 12/25/2022] Open
Abstract
Cortical dysplasia (CD) is a neurodevelopmental disorder due to aberrant cell proliferation and differentiation. Advances in neuroimaging have proven effective in early identification of the more severe lesions and timely surgical removal to treat epilepsy. However, the exact mechanisms of epileptogenesis are not well understood. This review examines possible mechanisms based on anatomical and electrophysiological studies. CD can be classified as CD type I consisting of architectural abnormalities, CD type II with the presence of dysmorphic cytomegalic neurons and balloon cells, and CD type III which occurs in association with other pathologies. Use of freshly resected brain tissue has allowed a better understanding of basic mechanisms of epileptogenesis and has delineated the role of abnormal cells and synaptic activity. In CD type II, it was demonstrated that balloon cells do not initiate epileptic activity, whereas dysmorphic cytomegalic and immature neurons play an important role in generation and propagation of epileptic discharges. An unexpected finding in pediatric CD was that GABA synaptic activity is not reduced, and in fact, it may facilitate the occurrence of epileptic activity. This could be because neuronal circuits display morphological and functional signs of dysmaturity. In consequence, drugs that increase GABA function may prove ineffective in pediatric CD. In contrast, drugs that counteract depolarizing actions of GABA or drugs that inhibit the mammalian target of rapamycin (mTOR) pathway could be more effective.
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Affiliation(s)
- Sara Abdijadid
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA
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15
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Rossini L, Medici V, Tassi L, Cardinale F, Tringali G, Bramerio M, Villani F, Spreafico R, Garbelli R. Layer-specific gene expression in epileptogenic type II focal cortical dysplasia: normal-looking neurons reveal the presence of a hidden laminar organization. Acta Neuropathol Commun 2014; 2:45. [PMID: 24735483 PMCID: PMC4023625 DOI: 10.1186/2051-5960-2-45] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/04/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type II focal cortical dysplasias (FCDs) are malformations of cortical development characterised by the disorganisation of the normal neocortical structure and the presence of dysmorphic neurons (DNs) and balloon cells (BCs). The pathogenesis of FCDs has not yet been clearly established, although a number of histopathological patterns and molecular findings suggest that they may be due to abnormal neuronal and glial proliferation and migration processes.In order to gain further insights into cortical layering disruption and investigate the origin of DNs and BCs, we used in situ RNA hybridisation of human surgical specimens with a neuropathologically definite diagnosis of Type IIa/b FCD and a panel of layer-specific genes (LSGs) whose expression covers all cortical layers. We also used anti-phospho-S6 ribosomal protein antibody to investigate mTOR pathway hyperactivation. RESULTS LSGs were expressed in both normal and abnormal cells (BCs and DNs) but their distribution was different. Normal-looking neurons, which were visibly reduced in the core of the lesion, were apparently located in the appropriate cortical laminae thus indicating a partial laminar organisation. On the contrary, DNs and BCs, labelled with anti-phospho-S6 ribosomal protein antibody, were spread throughout the cortex without any apparent rule and showed a highly variable LSG expression pattern. Moreover, LSGs did not reveal any differences between Type IIa and IIb FCD. CONCLUSION These findings suggest the existence of hidden cortical lamination involving normal-looking neurons, which retain their ability to migrate correctly in the cortex, unlike DNs which, in addition to their morphological abnormalities and mTOR hyperactivation, show an altered migratory pattern.Taken together these data suggest that an external or environmental hit affecting selected precursor cells during the very early stages of cortical development may disrupt normal cortical development.
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Affiliation(s)
- Laura Rossini
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Valentina Medici
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Laura Tassi
- C. Munari Epilepsy Surgery Centre, Niguarda Hospital, Milan, Italy
| | | | - Giovanni Tringali
- Department of Neurosurgery, Fondazione IRCCS, Istituto Neurologico “C. Besta”, Milan, Italy
| | | | - Flavio Villani
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Roberto Spreafico
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Rita Garbelli
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
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Inoue T, Kawawaki H, Kuki I, Nabatame S, Tomonoh Y, Sukigara S, Horino A, Nukui M, Okazaki S, Tomiwa K, Kimura-Ohba S, Inoue T, Hirose S, Shiomi M, Itoh M. A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging. J Neurol Sci 2013; 327:65-72. [PMID: 23422026 DOI: 10.1016/j.jns.2013.01.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/26/2012] [Accepted: 01/29/2013] [Indexed: 11/17/2022]
Abstract
Early-onset epileptic encephalopathies include various diseases such as early-infantile epileptic encephalopathy with suppression burst. We experimentally investigated the unique clinicopathological features of a 28-month-old girl with early-onset epileptic encephalopathy. Her initial symptom was intractable epilepsy with a suppression-burst pattern of electroencephalography (EEG) from 7 days of age. The suppression-burst pattern was novel, appearing during sleep, but disappearing upon waking and after becoming 2 months old. The EEG showed multifocal spikes and altered with age. Her seizures demonstrated various clinical features and continued until death. She did not show any developmental features, including no social smiling or head control. Head MRI revealed progressive atrophy of the cerebral cortex and white matter after 1 month of age. (123)IMZ-SPECT demonstrated hypo-perfusion of the cerebral cortex, but normo-perfusion of the diencephalon and cerebellum. Such imaging information indicated GABA-A receptor dysfunction of the cerebral cortex. The genetic analyses of major neonatal epilepsies showed no mutation. The neuropathology revealed atrophy and severe edema of the cerebral cortex and white matter. GAD-immunohistochemistry exhibited imbalanced distribution of GABAergic interneurons between the striatum and cerebral cortex. The results were similar to those of focal cortical dysplasia with transmantle sign and X-linked lissencephaly with ARX mutation. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge, her clinical and pathological courses have never been described in the literature.
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Affiliation(s)
- T Inoue
- Department of Child Neurology, Osaka City General Hospital, Osaka, Japan
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