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Lee HM, Hong SJ, Gill R, Caldairou B, Wang I, Zhang JG, Deleo F, Schrader D, Bartolomei F, Guye M, Cho KH, Barba C, Sisodiya S, Jackson G, Hogan RE, Wong-Kisiel L, Cascino GD, Schulze-Bonhage A, Lopes-Cendes I, Cendes F, Guerrini R, Bernhardt B, Bernasconi N, Bernasconi A. Multimodal mapping of regional brain vulnerability to focal cortical dysplasia. Brain 2023; 146:3404-3415. [PMID: 36852571 PMCID: PMC10393418 DOI: 10.1093/brain/awad060] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/17/2023] [Accepted: 02/02/2023] [Indexed: 03/01/2023] Open
Abstract
Focal cortical dysplasia (FCD) type II is a highly epileptogenic developmental malformation and a common cause of surgically treated drug-resistant epilepsy. While clinical observations suggest frequent occurrence in the frontal lobe, mechanisms for such propensity remain unexplored. Here, we hypothesized that cortex-wide spatial associations of FCD distribution with cortical cytoarchitecture, gene expression and organizational axes may offer complementary insights into processes that predispose given cortical regions to harbour FCD. We mapped the cortex-wide MRI distribution of FCDs in 337 patients collected from 13 sites worldwide. We then determined its associations with (i) cytoarchitectural features using histological atlases by Von Economo and Koskinas and BigBrain; (ii) whole-brain gene expression and spatiotemporal dynamics from prenatal to adulthood stages using the Allen Human Brain Atlas and PsychENCODE BrainSpan; and (iii) macroscale developmental axes of cortical organization. FCD lesions were preferentially located in the prefrontal and fronto-limbic cortices typified by low neuron density, large soma and thick grey matter. Transcriptomic associations with FCD distribution uncovered a prenatal component related to neuroglial proliferation and differentiation, likely accounting for the dysplastic makeup, and a postnatal component related to synaptogenesis and circuit organization, possibly contributing to circuit-level hyperexcitability. FCD distribution showed a strong association with the anterior region of the antero-posterior axis derived from heritability analysis of interregional structural covariance of cortical thickness, but not with structural and functional hierarchical axes. Reliability of all results was confirmed through resampling techniques. Multimodal associations with cytoarchitecture, gene expression and axes of cortical organization indicate that prenatal neurogenesis and postnatal synaptogenesis may be key points of developmental vulnerability of the frontal lobe to FCD. Concordant with a causal role of atypical neuroglial proliferation and growth, our results indicate that FCD-vulnerable cortices display properties indicative of earlier termination of neurogenesis and initiation of cell growth. They also suggest a potential contribution of aberrant postnatal synaptogenesis and circuit development to FCD epileptogenicity.
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Affiliation(s)
- Hyo M Lee
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Seok-Jun Hong
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
- Center for Neuroscience Imaging, Research Institute for Basic Science, Department of Global Biomedical Engineering, SungKyunKwan University, Suwon, KoreaSuwon, Korea
| | - Ravnoor Gill
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Benoit Caldairou
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Irene Wang
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jian-guo Zhang
- Department of Functional Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Francesco Deleo
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico C. Besta, Milano, Italy
| | - Dewi Schrader
- Department of Pediatrics, British Columbia Children’s Hospital, Vancouver, Canada
| | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, 13005, France
| | - Maxime Guye
- Aix Marseille University, CNRS, CRMBM UMR 7339, Marseille, France
| | - Kyoo Ho Cho
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
| | - Carmen Barba
- Meyer Children's Hospital IRCCS, Florence, Italy
- University of Florence, 50121 Florence, Italy
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Graeme Jackson
- The Florey Institute of Neuroscience and Mental Health and The University of Melbourne, Victoria, Australia
| | - R Edward Hogan
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | | | | | | | - Iscia Lopes-Cendes
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP) and the Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas SP, Brazil
| | - Fernando Cendes
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), and the Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas SP, Brazil
| | - Renzo Guerrini
- Meyer Children's Hospital IRCCS, Florence, Italy
- University of Florence, 50121 Florence, Italy
| | - Boris Bernhardt
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
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Gerasimenko A, Baldassari S, Baulac S. mTOR pathway: Insights into an established pathway for brain mosaicism in epilepsy. Neurobiol Dis 2023; 182:106144. [PMID: 37149062 DOI: 10.1016/j.nbd.2023.106144] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) signaling pathway is an essential regulator of numerous cellular activities such as metabolism, growth, proliferation, and survival. The mTOR cascade recently emerged as a critical player in the pathogenesis of focal epilepsies and cortical malformations. The 'mTORopathies' comprise a spectrum of cortical malformations that range from whole brain (megalencephaly) and hemispheric (hemimegalencephaly) abnormalities to focal abnormalities, such as focal cortical dysplasia type II (FCDII), which manifest with drug-resistant epilepsies. The spectrum of cortical dysplasia results from somatic brain mutations in the mTOR pathway activators AKT3, MTOR, PIK3CA, and RHEB and from germline and somatic mutations in mTOR pathway repressors, DEPDC5, NPRL2, NPRL3, TSC1 and TSC2. The mTORopathies are characterized by excessive mTOR pathway activation, leading to a broad range of structural and functional impairments. Here, we provide a comprehensive literature review of somatic mTOR-activating mutations linked to epilepsy and cortical malformations in 292 patients and discuss the perspectives of targeted therapeutics for personalized medicine.
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Affiliation(s)
- Anna Gerasimenko
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France; APHP Sorbonne Université, GH Pitié Salpêtrière et Trousseau, Département de Génétique, Centre de référence "déficiences intellectuelles de causes rares", Paris, France
| | - Sara Baldassari
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France.
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3
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Assis-Mendonça GR, Athié MCP, Tamanini JVG, de Souza A, Zanetti GG, Araújo PAORDA, Ghizoni E, Tedeschi H, Alvim MKM, de Almeida VS, de Souza W, Coras R, Yasuda CL, Blümcke I, Vieira AS, Cendes F, Lopes-Cendes I, Rogerio F. Transcriptome analyses of the cortex and white matter of focal cortical dysplasia type II: Insights into pathophysiology and tissue characterization. Front Neurol 2023; 14:1023950. [PMID: 37006485 PMCID: PMC10050872 DOI: 10.3389/fneur.2023.1023950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 01/26/2023] [Indexed: 03/17/2023] Open
Abstract
IntroductionFocal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy. According to the 2022 International League Against Epilepsy classification, FCD type II is characterized by dysmorphic neurons (IIa and IIb) and may be associated with balloon cells (IIb). We present a multicentric study to evaluate the transcriptomes of the gray and white matters of surgical FCD type II specimens. We aimed to contribute to pathophysiology and tissue characterization.MethodsWe investigated FCD II (a and b) and control samples by performing RNA-sequencing followed by immunohistochemical validation employing digital analyses.ResultsWe found 342 and 399 transcripts differentially expressed in the gray matter of IIa and IIb lesions compared to controls, respectively. Cholesterol biosynthesis was among the main enriched cellular pathways in both IIa and IIb gray matter. Particularly, the genes HMGCS1, HMGCR, and SQLE were upregulated in both type II groups. We also found 12 differentially expressed genes when comparing transcriptomes of IIa and IIb lesions. Only 1 transcript (MTRNR2L12) was significantly upregulated in FCD IIa. The white matter in IIa and IIb lesions showed 2 and 24 transcripts differentially expressed, respectively, compared to controls. No enriched cellular pathways were detected. GPNMB, not previously described in FCD samples, was upregulated in IIb compared to IIa and control groups. Upregulations of cholesterol biosynthesis enzymes and GPNMB genes in FCD groups were immunohistochemically validated. Such enzymes were mainly detected in both dysmorphic and normal neurons, whereas GPNMB was observed only in balloon cells.DiscussionOverall, our study contributed to identifying cortical enrichment of cholesterol biosynthesis in FCD type II, which may correspond to a neuroprotective response to seizures. Moreover, specific analyses in either the gray or the white matter revealed upregulations of MTRNR2L12 and GPNMB, which might be potential neuropathological biomarkers of a cortex chronically exposed to seizures and of balloon cells, respectively.
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Affiliation(s)
- Guilherme Rossi Assis-Mendonça
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Maria Carolina Pedro Athié
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - João Vitor Gerdulli Tamanini
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Arethusa de Souza
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Gabriel Gerardini Zanetti
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Patrícia Aline Oliveira Ribeiro de Aguiar Araújo
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Enrico Ghizoni
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Helder Tedeschi
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Marina Koutsodontis Machado Alvim
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Vanessa Simão de Almeida
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Welliton de Souza
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Clarissa Lin Yasuda
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - André Schwambach Vieira
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fernando Cendes
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fabio Rogerio
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- *Correspondence: Fabio Rogerio
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4
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Focal cortical dysplasia as a cause of epilepsy: The current evidence of associated genes and future therapeutic treatments. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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5
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KIF5C deficiency causes abnormal cortical neuronal migration, dendritic branching, and spine morphology in mice. Pediatr Res 2022; 92:995-1002. [PMID: 34966180 DOI: 10.1038/s41390-021-01922-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/18/2021] [Accepted: 12/13/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Malformation of cortical development (MCD) includes a variety of developmental disorders that are common causes of neurodevelopmental delay and epilepsy. Most recently, clinical studies found that patients carrying KIF5C mutations present early-onset MCD; however, the underlying mechanisms remain elusive. METHODS KIF5C expression level was examined in mouse primary cortical neurons and human ips-derived forebrain organoids. We studied the cortical neuronal migration, dendritic branching, and dendritic spine growth after knocking down the KIF5C gene by electroporation in vitro and in vivo. Then, we studied the transcriptome differences between the knockdown and control groups through RNA sequencing. RESULTS We observed high KIF5C expression in neurons during the early developmental stage in mice and the human brain. Kif5c deficiency results in disturbed cortical neuronal migration, dendritic, and spine growth. Finally, we found that Kif5c knockdown affected several genes associated with cortical neuronal development in vitro. CONCLUSIONS These results suggested a critical role for Kif5c in cortical development, providing insights into underlying pathogenic factors of kinesins in MCD. IMPACT KIF5C mutation-related MCD might be caused by abnormal early cortical neuronal development. Kif5c deficiency led to abnormal cortical neuronal dendritic and spine growth and neuronal migration. Our findings explain how Kif5c deficiency is involved in the aberrant development of cortical neurons and provide a new perspective for the pathology of MCD.
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6
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Kan Y, Feng L, Si Y, Zhou Z, Wang W, Yang J. Pathogenesis and Therapeutic Targets of Focal Cortical Dysplasia Based on Bioinformatics Analysis. Neurochem Res 2022; 47:3506-3521. [PMID: 35945307 DOI: 10.1007/s11064-022-03715-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/18/2022] [Accepted: 07/29/2022] [Indexed: 11/30/2022]
Abstract
Focal cortical dysplasia (FCD), a malformation of cortical development, is the most common cause of intractable epilepsy in children. However, the causes and underlying molecular events of FCD need further investigation. The microarray dataset GSE62019 and GSE97365 were obtained from Gene Expression Omnibus. To examine critical genes and signaling pathways, bioinformatics analysis tools such as protein-protein interaction (PPI) networks, miRNA-mRNA interaction networks, and immune infiltration in FCD samples were used to fully elucidate the pathogenesis of FCD. A total of 534 differentially expressed genes (DEGs) and 71 differentially expressed miRNAs (DEMs) were obtained. The DEGs obtained were enriched in ribosomal, protein targeting, and pathways of neurodegeneration multiple diseases, whereas the target genes of DEMs were enriched in signaling pathways such as transforming growth factor beta, Wnt, PI3K-Akt, etc. Finally, four hub genes (RPL11, FAU, RPS20, RPL27) and five key miRNAs (hsa-let-7b, hsa-miR-185, hsa-miR-23b, hsa-miR-222 and hsa-miR-92b) were obtained by PPI network, miRNA-mRNA network, and ROC analysis. The immune infiltration results showed that the infiltration levels of five immune cells (MDSC, regulatory T cells, activated CD8+ T cells, macrophage and effector memory CD8+ T cells) were slightly higher in FCD samples than in control samples. Moreover, the gene expressions of RPS19, RPL19, and RPS24 were highly correlated with the infiltration levels and immune characteristics of 28 immune cells. It broadens the understanding of the molecular mechanisms underlying the development of FCD and enlightens the identification of molecular targets and diagnostic biomarkers for FCD.
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Affiliation(s)
- Ying Kan
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Lijuan Feng
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Yukun Si
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Ziang Zhou
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Wei Wang
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Jigang Yang
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China.
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7
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Epigenetic genes and epilepsy - emerging mechanisms and clinical applications. Nat Rev Neurol 2022; 18:530-543. [PMID: 35859062 DOI: 10.1038/s41582-022-00693-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2022] [Indexed: 12/21/2022]
Abstract
An increasing number of epilepsies are being attributed to variants in genes with epigenetic functions. The products of these genes include factors that regulate the structure and function of chromatin and the placing, reading and removal of epigenetic marks, as well as other epigenetic processes. In this Review, we provide an overview of the various epigenetic processes, structuring our discussion around five function-based categories: DNA methylation, histone modifications, histone-DNA crosstalk, non-coding RNAs and chromatin remodelling. We provide background information on each category, describing the general mechanism by which each process leads to altered gene expression. We also highlight key clinical and mechanistic aspects, providing examples of genes that strongly associate with epilepsy within each class. We consider the practical applications of these findings, including tissue-based and biofluid-based diagnostics and precision medicine-based treatments. We conclude that variants in epigenetic genes are increasingly found to be causally involved in the epilepsies, with implications for disease mechanisms, treatments and diagnostics.
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8
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Seng C, Luo W, Földy C. Circuit formation in the adult brain. Eur J Neurosci 2022; 56:4187-4213. [PMID: 35724981 PMCID: PMC9546018 DOI: 10.1111/ejn.15742] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/30/2022]
Abstract
Neurons in the mammalian central nervous system display an enormous capacity for circuit formation during development but not later in life. In principle, new circuits could be also formed in adult brain, but the absence of the developmental milieu and the presence of growth inhibition and hundreds of working circuits are generally viewed as unsupportive for such a process. Here, we bring together evidence from different areas of neuroscience—such as neurological disorders, adult‐brain neurogenesis, innate behaviours, cell grafting, and in vivo cell reprogramming—which demonstrates robust circuit formation in adult brain. In some cases, adult‐brain rewiring is ongoing and required for certain types of behaviour and memory, while other cases show significant promise for brain repair in disease models. Together, these examples highlight that the adult brain has higher capacity for structural plasticity than previously recognized. Understanding the underlying mechanisms behind this retained plasticity has the potential to advance basic knowledge regarding the molecular organization of synaptic circuits and could herald a new era of neural circuit engineering for therapeutic repair.
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Affiliation(s)
- Charlotte Seng
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, Zürich, Switzerland
| | - Wenshu Luo
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, Zürich, Switzerland
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, Zürich, Switzerland
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9
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CfDNA Measurement as a Diagnostic Tool for the Detection of Brain Somatic Mutations in Refractory Epilepsy. Int J Mol Sci 2022; 23:ijms23094879. [PMID: 35563270 PMCID: PMC9102996 DOI: 10.3390/ijms23094879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/21/2022] [Accepted: 04/26/2022] [Indexed: 02/04/2023] Open
Abstract
Epilepsy is a neurological disorder that affects more than 50 million people. Its etiology is unknown in approximately 60% of cases, although the existence of a genetic factor is estimated in about 75% of these individuals. Hundreds of genes involved in epilepsy are known, and their number is increasing progressively, especially with next-generation sequencing techniques. However, there are still many cases in which the results of these molecular studies do not fully explain the phenotype of the patients. Somatic mutations specific to brain tissue could contribute to the phenotypic spectrum of epilepsy. Undetectable in the genomic DNA of blood cells, these alterations can be identified in cell-free DNA (cfDNA). We aim to review the current literature regarding the detection of somatic variants in cfDNA to diagnose refractory epilepsy, highlighting novel research directions and suggesting further studies.
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10
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Canto AM, Godoi AB, Matos AHB, Geraldis JC, Rogerio F, Alvim MKM, Yasuda CL, Ghizoni E, Tedeschi H, Veiga DFT, Henning B, Souza W, Rocha CS, Vieira AS, Dias EV, Carvalho BS, Gilioli R, Arul AB, Robinson RAS, Cendes F, Lopes-Cendes I. Benchmarking the proteomic profile of animal models of mesial temporal epilepsy. Ann Clin Transl Neurol 2022; 9:454-467. [PMID: 35238489 PMCID: PMC8994989 DOI: 10.1002/acn3.51533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES We compared the proteomic signatures of the hippocampal lesion induced in three different animal models of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS): the systemic pilocarpine model (PILO), the intracerebroventricular kainic acid model (KA), and the perforant pathway stimulation model (PPS). METHODS We used shotgun proteomics to analyze the proteomes and find enriched biological pathways of the dorsal and ventral dentate gyrus (DG) isolated from the hippocampi of the three animal models. We also compared the proteomes obtained in the animal models to that from the DG of patients with pharmacoresistant MTLE+HS. RESULTS We found that each animal model presents specific profiles of proteomic changes. The PILO model showed responses predominantly related to neuronal excitatory imbalance. The KA model revealed alterations mainly in synaptic activity. The PPS model displayed abnormalities in metabolism and oxidative stress. We also identified common biological pathways enriched in all three models, such as inflammation and immune response, which were also observed in tissue from patients. However, none of the models could recapitulate the profile of molecular changes observed in tissue from patients. SIGNIFICANCE Our results indicate that each model has its own set of biological responses leading to epilepsy. Thus, it seems that only using a combination of the three models may one replicate more closely the mechanisms underlying MTLE+HS as seen in patients.
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Affiliation(s)
- Amanda M Canto
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Alexandre B Godoi
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Alexandre H B Matos
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Jaqueline C Geraldis
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Fabio Rogerio
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Marina K M Alvim
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Clarissa L Yasuda
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Enrico Ghizoni
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Helder Tedeschi
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Diogo F T Veiga
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Barbara Henning
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Welliton Souza
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Cristiane S Rocha
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - André S Vieira
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Elayne V Dias
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Benilton S Carvalho
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Statistics, Institute of Mathematics, Statistics and Scientific Computing, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Rovilson Gilioli
- Laboratory of Animal Quality Control, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Albert B Arul
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, 37235, USA
| | - Renã A S Robinson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, 37235, USA
| | - Fernando Cendes
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.,Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
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11
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Martins-Ferreira R, Leal B, Chaves J, Li T, Ciudad L, Rangel R, Santos A, Martins da Silva A, Pinho Costa P, Ballestar E. Epilepsy progression is associated with cumulative DNA methylation changes in inflammatory genes. Prog Neurobiol 2022; 209:102207. [DOI: 10.1016/j.pneurobio.2021.102207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/02/2021] [Accepted: 12/14/2021] [Indexed: 01/09/2023]
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12
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Heng JIT, Viti L, Pugh K, Marshall OJ, Agostino M. Understanding the impact of ZBTB18 missense variation on transcription factor function in neurodevelopment and disease. J Neurochem 2022; 161:219-235. [PMID: 35083747 PMCID: PMC9302683 DOI: 10.1111/jnc.15572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/13/2021] [Accepted: 01/07/2022] [Indexed: 12/01/2022]
Abstract
Mutations to genes that encode DNA‐binding transcription factors (TFs) underlie a broad spectrum of human neurodevelopmental disorders. Here, we highlight the pathological mechanisms arising from mutations to TF genes that influence the development of mammalian cerebral cortex neurons. Drawing on recent findings for TF genes including ZBTB18, we discuss how functional missense mutations to such genes confer non‐native gene regulatory actions in developing neurons, leading to cell‐morphological defects, neuroanatomical abnormalities during foetal brain development and functional impairment. Further, we discuss how missense variation to human TF genes documented in the general population endow quantifiable changes to transcriptional regulation, with potential cell biological effects on the temporal progression of cerebral cortex neuron development and homeostasis. We offer a systematic approach to investigate the functional impact of missense variation in brain TFs and define their direct molecular and cellular actions in foetal neurodevelopment, tissue homeostasis and disease states.![]()
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Affiliation(s)
- Julian I-T Heng
- Curtin Health Innovation Research Institute, Bentley, WA, Australia.,Curtin Neuroscience Laboratories, Sarich Neuroscience Institute, Crawley, WA, Australia.,Curtin Medical School, Curtin University, Bentley, WA, Australia
| | - Leon Viti
- Curtin Health Innovation Research Institute, Bentley, WA, Australia.,Curtin Medical School, Curtin University, Bentley, WA, Australia
| | - Kye Pugh
- Curtin Health Innovation Research Institute, Bentley, WA, Australia.,Curtin Medical School, Curtin University, Bentley, WA, Australia
| | - Owen J Marshall
- Menzies Institute for Medical Research, The University of Tasmania, Hobart, Australia
| | - Mark Agostino
- Curtin Health Innovation Research Institute, Bentley, WA, Australia.,Curtin Institute for Computation, Curtin University, Bentley, Western Australia, Australia
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13
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Cortical Dysplasia and the mTOR Pathway: How the Study of Human Brain Tissue Has Led to Insights into Epileptogenesis. Int J Mol Sci 2022; 23:ijms23031344. [PMID: 35163267 PMCID: PMC8835853 DOI: 10.3390/ijms23031344] [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: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/16/2022] [Indexed: 02/01/2023] Open
Abstract
Type II focal cortical dysplasia (FCD) is a neuropathological entity characterised by cortical dyslamination with the presence of dysmorphic neurons only (FCDIIA) or the presence of both dysmorphic neurons and balloon cells (FCDIIB). The year 2021 marks the 50th anniversary of the recognition of FCD as a cause of drug resistant epilepsy, and it is now the most common reason for epilepsy surgery. The causes of FCD remained unknown until relatively recently. The study of resected human FCD tissue using novel genomic technologies has led to remarkable advances in understanding the genetic basis of FCD. Mechanistic parallels have emerged between these non-neoplastic lesions and neoplastic disorders of cell growth and differentiation, especially through perturbations of the mammalian target of rapamycin (mTOR) signalling pathway. This narrative review presents the advances through which the aetiology of FCDII has been elucidated in chronological order, from recognition of an association between FCD and the mTOR pathway to the identification of somatic mosaicism within FCD tissue. We discuss the role of a two-hit mechanism, highlight current challenges and future directions in detecting somatic mosaicism in brain and discuss how knowledge of FCD may inform novel precision treatments of these focal epileptogenic malformations of human cortical development.
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14
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Blumcke I, Cendes F, Miyata H, Thom M, Aronica E, Najm I. Toward a refined genotype-phenotype classification scheme for the international consensus classification of Focal Cortical Dysplasia. Brain Pathol 2021; 31:e12956. [PMID: 34196989 PMCID: PMC8412090 DOI: 10.1111/bpa.12956] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 12/28/2022] Open
Abstract
Focal Cortical Dysplasia (FCD) is the most common cause of drug-resistant focal epilepsy in children and young adults. The diagnosis of currently defined FCD subtypes relies on a histopathological assessment of surgical brain tissue. The many ongoing challenges in the diagnosis of FCD and their various subtypes mandate, however, continuous research and consensus agreement to develop a reliable classification scheme. Advanced neuroimaging and genetic studies have proven to augment the diagnosis of FCD subtypes and should be considered for an integrated clinico-pathological and molecular classification. In this review, we will discuss the histopathological foundation of the current FCD classification and potential advancements when using genetic analysis of somatic brain mutations in neurosurgically resected brain specimens and postprocessing of presurgical neuroimaging data. Combining clinical, imaging, histopathology, and molecular studies will help to define the disease spectrum better and finally unveil FCD-specific treatment options.
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Affiliation(s)
- Ingmar Blumcke
- Department of NeuropathologyUniversity Hospital ErlangenFriedrich‐Alexander‐University Erlangen‐NürnbergErlangenGermany
- Epilepsy CenterCleveland Clinic FoundationClevelandOHUSA
| | - Fernando Cendes
- Department of NeurologyUniversity of Campinas—UNICAMPCampinasSPBrazil
| | - Hajime Miyata
- Department of NeuropathologyResearch Institute for Brain and Blood VesselsAkita Cerebrospinal and Cardiovascular CenterAkitaJapan
| | - Maria Thom
- Department of NeuropathologyInstitute of Neurology, University College LondonLondonUK
| | - Eleonora Aronica
- Department of (Neuro)PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam
- Stichting Epilepsie Instellingen Nederland (SEINHeemstedeThe Netherlands
| | - Imad Najm
- Epilepsy CenterCleveland Clinic FoundationClevelandOHUSA
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15
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Jesus-Ribeiro J, Pires LM, Melo JD, Ribeiro IP, Rebelo O, Sales F, Freire A, Melo JB. Genomic and Epigenetic Advances in Focal Cortical Dysplasia Types I and II: A Scoping Review. Front Neurosci 2021; 14:580357. [PMID: 33551717 PMCID: PMC7862327 DOI: 10.3389/fnins.2020.580357] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 12/14/2020] [Indexed: 12/19/2022] Open
Abstract
Introduction: Focal cortical dysplasias (FCDs) are a group of malformations of cortical development that constitute a common cause of drug-resistant epilepsy, often subjected to neurosurgery, with a suboptimal long-term outcome. The past few years have witnessed a dramatic leap in our understanding of the molecular basis of FCD. This study aimed to provide an updated review on the genomic and epigenetic advances underlying FCD etiology, to understand a genotype-phenotype correlation and identify priorities to lead future translational research. Methods: A scoping review of the literature was conducted, according to previously described methods. A comprehensive search strategy was applied in PubMed, Embase, and Web of Science from inception to 07 May 2020. References were screened based on title and abstract, and posteriorly full-text articles were assessed for inclusion according to eligibility criteria. Studies with novel gene variants or epigenetic regulatory mechanisms in patients that underwent epilepsy surgery, with histopathological diagnosis of FCD type I or II according to Palmini's or the ILAE classification system, were included. Data were extracted and summarized for an overview of evidence. Results: Of 1,156 candidate papers, 39 met the study criteria and were included in this review. The advent of next-generation sequencing enabled the detection in resected FCD tissue of low-level brain somatic mutations that occurred during embryonic corticogenesis. The mammalian target of rapamycin (mTOR) signaling pathway, involved in neuronal growth and migration, is the key player in the pathogenesis of FCD II. Somatic gain-of-function variants in MTOR and its activators as well as germline, somatic, and second-hit mosaic loss-of-function variants in its related repressors have been reported. However, the genetic background of FCD type I remains elusive, with a pleomorphic repertoire of genes affected. DNA methylation and microRNAs were the two epigenetic mechanisms that proved to have a functional role in FCD and may represent molecular biomarkers. Conclusion: Further research into the possible pathogenic causes of both FCD subtypes is required, incorporating single-cell DNA/RNA sequencing as well as methylome and proteomic analysis. The collected data call for an integrated clinicopathologic and molecular genetic diagnosis in current practice not only to improve diagnostic accuracy but also to guide the development of future targeted treatments.
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Affiliation(s)
- Joana Jesus-Ribeiro
- Epilepsy and Sleep Monitoring Unit, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal.,iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Luís Miguel Pires
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | | | - Ilda Patrícia Ribeiro
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Olinda Rebelo
- Neuropathology Laboratory, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal
| | - Francisco Sales
- Epilepsy and Sleep Monitoring Unit, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal
| | - António Freire
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Joana Barbosa Melo
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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16
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Abstract
Rnd proteins constitute a subfamily of Rho GTPases represented in mammals by Rnd1, Rnd2 and Rnd3. Despite their GTPase structure, their specific feature is the inability to hydrolyse GTP-bound nucleotide. This aspect makes them atypical among Rho GTPases. Rnds are regulated for their expression at the transcriptional or post-transcriptional levels and they are activated through post-translational modifications and interactions with other proteins. Rnd proteins are mainly involved in the regulation of the actin cytoskeleton and cell proliferation. Whereas Rnd3 is ubiquitously expressed, Rnd1 and 2 are tissue-specific. Increasing data has described their important role during development and diseases. Herein, we describe their involvement in physiological and pathological conditions with a focus on the neuronal and vascular systems, and summarize their implications in tumorigenesis.
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Affiliation(s)
- Sara Basbous
- INSERM, BaRITOn, U1053, F-33000, Univ. Bordeaux, Bordeaux, France
| | - Roberta Azzarelli
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, Pisa, Italy
| | - Emilie Pacary
- INSERM, U1215 - Neurocentre Magendie, F-33077, Univ. Bordeaux, Bordeaux, France
| | - Violaine Moreau
- INSERM, BaRITOn, U1053, F-33000, Univ. Bordeaux, Bordeaux, France
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17
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MicroRNAs as regulators of brain function and targets for treatment of epilepsy. Nat Rev Neurol 2020; 16:506-519. [DOI: 10.1038/s41582-020-0369-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2020] [Indexed: 02/07/2023]
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18
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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: 5] [Impact Index Per Article: 1.0] [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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19
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Ye Z, McQuillan L, Poduri A, Green TE, Matsumoto N, Mefford HC, Scheffer IE, Berkovic SF, Hildebrand MS. Somatic mutation: The hidden genetics of brain malformations and focal epilepsies. Epilepsy Res 2019; 155:106161. [PMID: 31295639 DOI: 10.1016/j.eplepsyres.2019.106161] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 01/12/2023]
Abstract
Over the past decade there has been a substantial increase in genetic studies of brain malformations, fueled by the availability of improved technologies to study surgical tissue to address the hypothesis that focal lesions arise from focal, post-zygotic genetic disruptions. Traditional genetic studies of patients with malformations utilized leukocyte-derived DNA to search for germline variants, which are inherited or arise de novo in parental gametes. Recent studies have demonstrated somatic variants that arise post-zygotically also underlie brain malformations, and that somatic mutation explains a larger proportion of focal malformations than previously thought. We now know from studies of non-diseased individuals that somatic variation occurs routinely during cell division, including during early brain development when the rapid proliferation of neuronal precursor cells provides the ideal environment for somatic mutation to occur and somatic variants to accumulate. When confined to brain, pathogenic variants contribute to the "hidden genetics" of neurological diseases. With burgeoning novel high-throughput genetic technologies, somatic genetic variations are increasingly being recognized. Here we discuss accumulating evidence for the presence of somatic variants in normal brain tissue, review our current understanding of somatic variants in brain malformations associated with lesional epilepsy, and provide strategies to identify the potential contribution of somatic mutation to non-lesional epilepsies. We also discuss technologies that may improve detection of somatic variants in the future in these and other neurological conditions.
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Affiliation(s)
- Zimeng Ye
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Lara McQuillan
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Timothy E Green
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, WA, United States
| | - Ingrid E Scheffer
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Michael S Hildebrand
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
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20
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Chua CEL, Tang BL. miR-34a in Neurophysiology and Neuropathology. J Mol Neurosci 2018; 67:235-246. [DOI: 10.1007/s12031-018-1231-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 11/22/2018] [Indexed: 12/28/2022]
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21
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MTOR pathway in focal cortical dysplasia type 2: What do we know? Epilepsy Behav 2018; 85:157-163. [PMID: 29945038 DOI: 10.1016/j.yebeh.2018.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 01/15/2023]
Abstract
Focal cortical dysplasia (FCD) is the most commonly encountered developmental malformation that causes refractory epilepsy. Focal cortical dysplasia type 2 is one of the most usual neuropathological findings in tissues resected therapeutically from patients with drug-resistant epilepsy. Unlike other types of FCD, it is characterized by laminar disorganization and dysplastic neurons, which compromise the organization of the six histologically known layers in the cortex; the morphology and/or cell location can also be altered. A comprehensive review about the pathogenesis of this disease is important because of the necessity to update the results reported over the past years. Here, we present an updated review through Pubmed about the mammalian target of rapamycin (MTOR) pathway in FCD type 2. A wide variety of aspects was covered in 44 articles related to molecular and cellular biology, including experiments in animal and human models. The first publications appeared in 2004, but there is still a lack of studies specifically for one type of FCD. With the advancement of techniques and greater access to molecular and cellular experiments, such as induced pluripotent stem cells (iPSCs) and organoids, it is believed that the trend is increasing the number of publications contributing to the achievement of new discoveries.
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