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Raptor downregulation rescues neuronal phenotypes in mouse models of Tuberous Sclerosis Complex. Nat Commun 2022; 13:4665. [PMID: 35945201 PMCID: PMC9363483 DOI: 10.1038/s41467-022-31961-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 07/08/2022] [Indexed: 12/16/2022] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations in the TSC1 or TSC2 genes, which encode proteins that negatively regulate mTOR complex 1 (mTORC1) signaling. Current treatment strategies focus on mTOR inhibition with rapamycin and its derivatives. While effective at improving some aspects of TSC, chronic rapamycin inhibits both mTORC1 and mTORC2 and is associated with systemic side-effects. It is currently unknown which mTOR complex is most relevant for TSC-related brain phenotypes. Here we used genetic strategies to selectively reduce neuronal mTORC1 or mTORC2 activity in mouse models of TSC. We find that reduction of the mTORC1 component Raptor, but not the mTORC2 component Rictor, rebalanced mTOR signaling in Tsc1 knock-out neurons. Raptor reduction was sufficient to improve several TSC-related phenotypes including neuronal hypertrophy, macrocephaly, impaired myelination, network hyperactivity, and premature mortality. Raptor downregulation represents a promising potential therapeutic intervention for the neurological manifestations of TSC.
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2
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Eichmüller OL, Corsini NS, Vértesy Á, Morassut I, Scholl T, Gruber VE, Peer AM, Chu J, Novatchkova M, Hainfellner JA, Paredes MF, Feucht M, Knoblich JA. Amplification of human interneuron progenitors promotes brain tumors and neurological defects. Science 2022; 375:eabf5546. [PMID: 35084981 PMCID: PMC7613689 DOI: 10.1126/science.abf5546] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Evolutionary development of the human brain is characterized by the expansion of various brain regions. Here, we show that developmental processes specific to humans are responsible for malformations of cortical development (MCDs), which result in developmental delay and epilepsy in children. We generated a human cerebral organoid model for tuberous sclerosis complex (TSC) and identified a specific neural stem cell type, caudal late interneuron progenitor (CLIP) cells. In TSC, CLIP cells over-proliferate, generating excessive interneurons, brain tumors, and cortical malformations. Epidermal growth factor receptor inhibition reduces tumor burden, identifying potential treatment options for TSC and related disorders. The identification of CLIP cells reveals the extended interneuron generation in the human brain as a vulnerability for disease. In addition, this work demonstrates that analyzing MCDs can reveal fundamental insights into human-specific aspects of brain development.
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Affiliation(s)
- Oliver L. Eichmüller
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
- University of Heidelberg, Heidelberg, Germany
| | - Nina S. Corsini
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
| | - Ábel Vértesy
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
| | - Ilaria Morassut
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
| | - Theresa Scholl
- Medical University of Vienna, Department of Pediatric and Adolescent Medicine, Vienna, Austria
| | | | - Angela M. Peer
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
| | - Julia Chu
- Department of Neurology, University of California, San Francisco, USA
| | - Maria Novatchkova
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
| | | | | | - Martha Feucht
- Medical University of Vienna, Department of Pediatric and Adolescent Medicine, Vienna, Austria
| | - Jürgen A. Knoblich
- IMBA − Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
- Medical University of Vienna, Department of Neurology, Vienna, Austria
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3
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Korotkov A, Sim NS, Luinenburg MJ, Anink JJ, van Scheppingen J, Zimmer TS, Bongaarts A, Broekaart DWM, Mijnsbergen C, Jansen FE, Van Hecke W, Spliet WGM, van Rijen PC, Feucht M, Hainfellner JA, Kršek P, Zamecnik J, Crino PB, Kotulska K, Lagae L, Jansen AC, Kwiatkowski DJ, Jozwiak S, Curatolo P, Mühlebner A, Lee JH, Mills JD, van Vliet EA, Aronica E. MicroRNA-34a activation in tuberous sclerosis complex during early brain development may lead to impaired corticogenesis. Neuropathol Appl Neurobiol 2021; 47:796-811. [PMID: 33942341 PMCID: PMC8519131 DOI: 10.1111/nan.12717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 01/26/2021] [Accepted: 04/19/2021] [Indexed: 12/14/2022]
Abstract
AIMS Tuberous sclerosis complex (TSC) is a genetic disorder associated with dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1) signalling pathway. Neurodevelopmental disorders, frequently present in TSC, are linked to cortical tubers in the brain. We previously reported microRNA-34a (miR-34a) among the most upregulated miRs in tubers. Here, we characterised miR-34a expression in tubers with the focus on the early brain development and assessed the regulation of mTORC1 pathway and corticogenesis by miR-34a. METHODS We analysed the expression of miR-34a in resected cortical tubers (n = 37) compared with autopsy-derived control tissue (n = 27). The effect of miR-34a overexpression on corticogenesis was assessed in mice at E18. The regulation of the mTORC1 pathway and the expression of the bioinformatically predicted target genes were assessed in primary astrocyte cultures from three patients with TSC and in SH-SY5Y cells following miR-34a transfection. RESULTS The peak of miR-34a overexpression in tubers was observed during infancy, concomitant with the presence of pathological markers, particularly in giant cells and dysmorphic neurons. miR-34a was also strongly expressed in foetal TSC cortex. Overexpression of miR-34a in mouse embryos decreased the percentage of cells migrated to the cortical plate. The transfection of miR-34a mimic in TSC astrocytes negatively regulated mTORC1 and decreased the expression of the target genes RAS related (RRAS) and NOTCH1. CONCLUSIONS MicroRNA-34a is most highly overexpressed in tubers during foetal and early postnatal brain development. miR-34a can negatively regulate mTORC1; however, it may also contribute to abnormal corticogenesis in TSC.
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Affiliation(s)
- Anatoly Korotkov
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Nam Suk Sim
- Graduate School of Medical Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeonRepublic of Korea
| | - Mark J. Luinenburg
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Jasper J. Anink
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Jackelien van Scheppingen
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
- Department of NeuroimmunologyNetherlands Institute for NeuroscienceAmsterdamThe Netherlands
| | - Till S. Zimmer
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Anika Bongaarts
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Diede W. M. Broekaart
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Caroline Mijnsbergen
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Floor E. Jansen
- Department of Paediatric NeurologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Wim Van Hecke
- Department of PathologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Wim G. M. Spliet
- Department of PathologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Peter C. van Rijen
- University Medical CenterBrain CentreRudolf Magnus Institute for NeuroscienceUtrechtThe Netherlands
| | - Martha Feucht
- Department of PediatricsMedical University ViennaViennaAustria
| | | | - Pavel Kršek
- Department of Pediatric Neurology2nd Faculty of Medicine and Motol University HospitalPragueCzech Republic
| | - Josef Zamecnik
- Department of Pathology and Molecular Medicine2nd Faculty of Medicine and Motol University HospitalPragueCzech Republic
| | - Peter B. Crino
- Department of NeurologyUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Katarzyna Kotulska
- Department of Neurology and EpileptologyThe Children's Memorial Health InstituteWarsawPoland
| | - Lieven Lagae
- Department of Development and Regeneration‐Section Pediatric NeurologyUniversity Hospitals KU LeuvenLeuvenBelgium
| | - Anna C. Jansen
- Pediatric Neurology UnitUniversitair Ziekenhuis BrusselBrusselsBelgium
| | | | - Sergiusz Jozwiak
- Department of Neurology and EpileptologyThe Children's Memorial Health InstituteWarsawPoland
- Department of Child NeurologyMedical University of WarsawWarsawPoland
| | - Paolo Curatolo
- Child Neurology and Psychiatry UnitSystems Medicine DepartmentTor Vergata UniversityRomeItaly
| | - Angelika Mühlebner
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
| | - Jeong H. Lee
- Graduate School of Medical Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeonRepublic of Korea
- SoVarGen, IncDaejeonRepublic of Korea
| | - James D. Mills
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
- Department of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
- Chalfont Centre for EpilepsyChalfont St PeterUK
| | - Erwin A. van Vliet
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
- Center for NeuroscienceSwammerdam Institute for Life SciencesUniversity of AmsterdamAmsterdamThe Netherlands
| | - Eleonora Aronica
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdam NeuroscienceAmsterdamThe Netherlands
- Stichting Epilepsie Instellingen NederlandHeemstedeThe Netherlands
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4
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Gruber V, Lang J, Endmayr V, Diehm R, Pimpel B, Glatter S, Anink JJ, Bongaarts A, Luinenburg MJ, Reinten RJ, van der Wel N, Larsen P, Hainfellner JA, Rössler K, Aronica E, Scholl T, Mühlebner A, Feucht M. Impaired myelin production due to an intrinsic failure of oligodendrocytes in mTORpathies. Neuropathol Appl Neurobiol 2021; 47:812-825. [PMID: 34173252 PMCID: PMC8518586 DOI: 10.1111/nan.12744] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/24/2021] [Indexed: 12/22/2022]
Abstract
AIMS We aim to evaluate if the myelin pathology observed in epilepsy-associated focal cortical dysplasia type 2B (FCD2B) and-histologically indistinguishable-cortical tubers of tuberous sclerosis complex (TSC) is primarily related to the underlying malformation or constitutes a secondary phenomenon due to the toxic microenvironment created by epileptic seizures. We also aim to investigate the possible beneficial effect of the mTOR pathway regulator everolimus on white matter pathology. METHODS Primary mixed glial cell cultures derived from epilepsy surgery specimens of one TSC and seven FCD2B patients were grown on polycaprolactone fibre matrices and analysed using immunofluorescence and electron microscopy. Unaffected white matter from three age-matched epilepsy patients with mild malformations of cortical development (mMCD) and one with FCD3D served as controls. Additionally, TSC2 knock-out was performed using an oligodendroglial cell line. Myelination capacities of nanofibre grown cells in an inflammatory environment after mTOR-inhibitor treatment with everolimus were further investigated. RESULTS Reduced oligodendroglial turnover, directly related to a lower myelin content was found in the patients' primary cells. In our culture model of myelination dynamics, primary cells grown under 'inflammatory condition' showed decreased myelination, that was repaired by treatment with everolimus. CONCLUSIONS Results obtained in patient-derived primary oligodendroglial and TSC2 knock-out cells suggest that maturation of oligodendroglia and production of a proper myelin sheath seem to be impaired as a result of mTOR pathway disturbance. Hence, oligodendroglial pathology may reflect a more direct effect of the abnormal genetic programme rather than to be an inactive bystander of chronic epilepsy.
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Affiliation(s)
- Victoria‐Elisabeth Gruber
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Judith Lang
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Verena Endmayr
- Division of Neuropathology and Neurochemistry, Department of NeurologyMedical University of ViennaViennaAustria
| | - Robert Diehm
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Birgit Pimpel
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Sarah Glatter
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Jasper J. Anink
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Anika Bongaarts
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Mark J. Luinenburg
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Roy J. Reinten
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Nicole van der Wel
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Per Larsen
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Johannes A. Hainfellner
- Division of Neuropathology and Neurochemistry, Department of NeurologyMedical University of ViennaViennaAustria
| | - Karl Rössler
- Department of NeurosurgeryMedical University of ViennaViennaAustria
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN)HeemstedeThe Netherlands
| | - Theresa Scholl
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
| | - Angelika Mühlebner
- Department of PathologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Martha Feucht
- Department of Pediatrics and Adolescent MedicineMedical University of Vienna – Affiliated Partner of the ERN EpiCAREViennaAustria
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5
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Malchow RP, Tchernookova BK, Choi JIV, Smith PJS, Kramer RH, Kreitzer MA. Review and Hypothesis: A Potential Common Link Between Glial Cells, Calcium Changes, Modulation of Synaptic Transmission, Spreading Depression, Migraine, and Epilepsy-H . Front Cell Neurosci 2021; 15:693095. [PMID: 34539347 PMCID: PMC8446203 DOI: 10.3389/fncel.2021.693095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023] Open
Abstract
There is significant evidence to support the notion that glial cells can modulate the strength of synaptic connections between nerve cells, and it has further been suggested that alterations in intracellular calcium are likely to play a key role in this process. However, the molecular mechanism(s) by which glial cells modulate neuronal signaling remains contentiously debated. Recent experiments have suggested that alterations in extracellular H+ efflux initiated by extracellular ATP may play a key role in the modulation of synaptic strength by radial glial cells in the retina and astrocytes throughout the brain. ATP-elicited alterations in H+ flux from radial glial cells were first detected from Müller cells enzymatically dissociated from the retina of tiger salamander using self-referencing H+-selective microelectrodes. The ATP-elicited alteration in H+ efflux was further found to be highly evolutionarily conserved, extending to Müller cells isolated from species as diverse as lamprey, skate, rat, mouse, monkey and human. More recently, self-referencing H+-selective electrodes have been used to detect ATP-elicited alterations in H+ efflux around individual mammalian astrocytes from the cortex and hippocampus. Tied to increases in intracellular calcium, these ATP-induced extracellular acidifications are well-positioned to be key mediators of synaptic modulation. In this article, we examine the evidence supporting H+ as a key modulator of neurotransmission, review data showing that extracellular ATP elicits an increase in H+ efflux from glial cells, and describe the potential signal transduction pathways involved in glial cell-mediated H+ efflux. We then examine the potential role that extracellular H+ released by glia might play in regulating synaptic transmission within the vertebrate retina, and then expand the focus to discuss potential roles in spreading depression, migraine, epilepsy, and alterations in brain rhythms, and suggest that alterations in extracellular H+ may be a unifying feature linking these disparate phenomena.
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Affiliation(s)
- Robert Paul Malchow
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Boriana K. Tchernookova
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Ji-in Vivien Choi
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
- Stritch School of Medicine, Loyola University, Maywood, IL, United States
| | - Peter J. S. Smith
- Institute for Life Sciences, University of Southampton, Highfield Campus, Southampton, United Kingdom
- Bell Center, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Richard H. Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Matthew A. Kreitzer
- Department of Biology, Indiana Wesleyan University, Marion, IN, United States
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6
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Lobanov OV, Shimony JS, Kenley J, Kaplan S, Alexopoulos D, Roland JL, Smyth MD, Smyser CD. Alterations in resting-state functional connectivity in pediatric patients with tuberous sclerosis complex. Epilepsia Open 2021; 6:579-587. [PMID: 34268913 PMCID: PMC8408601 DOI: 10.1002/epi4.12523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/28/2021] [Accepted: 06/27/2021] [Indexed: 02/03/2023] Open
Abstract
Objective To investigate resting‐state functional connectivity (FC) in pediatric patients with tuberous sclerosis complex and intractable epilepsy requiring surgery. Methods Resting‐state functional MRI was utilized to investigate functional connectivity in 13 pediatric patients with tuberous sclerosis complex (TSC) and intractable epilepsy requiring surgery. Results The majority of patients demonstrated a resting‐state network architecture similar to those reported in healthy individuals. However, preoperative differences were evident between patients with high versus low tuber burden, as well as those with good versus poor neurodevelopmental outcomes, most notably in the cingulo‐opercular and visual resting‐state networks. One patient with high tuber burden and poor preoperative development and seizure control had nearly normal development and seizure resolution after surgery. This was accompanied by significant improvement in resting‐state network architecture just one day postoperatively. Significance Although many patients with tuberous sclerosis complex and medically refractory epilepsy demonstrate functional connectivity patterns similar to healthy children, relationships within and between RSNs demonstrate clear differences in patients with higher tuber burden and worse outcomes. Improvements in resting‐state network organization postoperatively may be related to epilepsy surgery outcomes, providing candidate biomarkers for clinical management in this high‐risk population.
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Affiliation(s)
- Oleg V Lobanov
- Department of Neurology, Washington University, St. Louis, MO, USA
| | - Joshua S Shimony
- Department of Radiology, Washington University, St. Louis, MO, USA
| | - Jeanette Kenley
- Department of Neurology, Washington University, St. Louis, MO, USA
| | - Sydney Kaplan
- Department of Neurology, Washington University, St. Louis, MO, USA
| | | | - Jarod L Roland
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Matthew D Smyth
- Department of Neurological Surgery, Washington University, St. Louis, MO, USA.,Department of Pediatrics, Washington University, St. Louis, MO, USA
| | - Christopher D Smyser
- Department of Neurology, Washington University, St. Louis, MO, USA.,Department of Radiology, Washington University, St. Louis, MO, USA.,Department of Pediatrics, Washington University, St. Louis, MO, USA
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7
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Mizuguchi M, Ohsawa M, Kashii H, Sato A. Brain Symptoms of Tuberous Sclerosis Complex: Pathogenesis and Treatment. Int J Mol Sci 2021; 22:ijms22136677. [PMID: 34206526 PMCID: PMC8268912 DOI: 10.3390/ijms22136677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/16/2021] [Accepted: 06/19/2021] [Indexed: 12/12/2022] Open
Abstract
The mammalian target of the rapamycin (mTOR) system plays multiple, important roles in the brain, regulating both morphology, such as cellular size, shape, and position, and function, such as learning, memory, and social interaction. Tuberous sclerosis complex (TSC) is a congenital disorder caused by a defective suppressor of the mTOR system, the TSC1/TSC2 complex. Almost all brain symptoms of TSC are manifestations of an excessive activity of the mTOR system. Many children with TSC are afflicted by intractable epilepsy, intellectual disability, and/or autism. In the brains of infants with TSC, a vicious cycle of epileptic encephalopathy is formed by mTOR hyperactivity, abnormal synaptic structure/function, and excessive epileptic discharges, further worsening epilepsy and intellectual/behavioral disorders. Molecular target therapy with mTOR inhibitors has recently been proved to be efficacious for epilepsy in human TSC patients, and for autism in TSC model mice, indicating the possibility for pharmacological treatment of developmental synaptic disorders.
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Affiliation(s)
- Masashi Mizuguchi
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;
- Department of Pediatrics, National Rehabilitation Center for Children with Disabilities, Itabashi-ku, Tokyo 173-0037, Japan
- Correspondence: ; Tel.: +81-3-5841-3515
| | - Maki Ohsawa
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;
- Department of Pediatrics, National Rehabilitation Center for Children with Disabilities, Itabashi-ku, Tokyo 173-0037, Japan
| | - Hirofumi Kashii
- Department of Neuropediatrics, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyo 183-0042, Japan;
| | - Atsushi Sato
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan;
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8
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Zimmer TS, Broekaart DWM, Luinenburg M, Mijnsbergen C, Anink JJ, Sim NS, Michailidou I, Jansen FE, van Rijen PC, Lee JH, François L, van Eyll J, Dedeurwaerdere S, van Vliet EA, Mühlebner A, Mills JD, Aronica E. Balloon cells promote immune system activation in focal cortical dysplasia type 2b. Neuropathol Appl Neurobiol 2021; 47:826-839. [PMID: 34003514 PMCID: PMC8518746 DOI: 10.1111/nan.12736] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/12/2021] [Indexed: 11/29/2022]
Abstract
Aims Focal cortical dysplasia (FCD) type 2 is an epileptogenic malformation of the neocortex associated with somatic mutations in the mammalian target of rapamycin (mTOR) pathway. Histopathologically, FCD 2 is subdivided into FCD 2a and FCD 2b, the only discriminator being the presence of balloon cells (BCs) in FCD 2b. While pro‐epileptogenic immune system activation and inflammatory responses are commonly detected in both subtypes, it is unknown what contextual role BCs play. Methods The present study employed RNA sequencing of surgically resected brain tissue from FCD 2a (n = 11) and FCD 2b (n = 20) patients compared to autopsy control (n = 9) focusing on three immune system processes: adaptive immunity, innate immunity and cytokine production. This analysis was followed by immunohistochemistry on a clinically well‐characterised FCD 2 cohort. Results Differential expression analysis revealed stronger expression of components of innate immunity, adaptive immunity and cytokine production in FCD 2b than in FCD 2a, particularly complement activation and antigen presentation. Immunohistochemical analysis confirmed these findings, with strong expression of leukocyte antigen I and II in FCD 2b as compared to FCD 2a. Moreover, T‐lymphocyte tissue infiltration was elevated in FCD 2b. Expression of markers of immune system activation in FCD 2b was concentrated in subcortical white matter. Lastly, antigen presentation was strongly correlated with BC load in FCD 2b lesions. Conclusion We conclude that, next to mutation‐driven mTOR activation and seizure activity, BCs are crucial drivers of inflammation in FCD 2b. Our findings indicate that therapies targeting inflammation may be beneficial in FCD 2b.
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Affiliation(s)
- Till S Zimmer
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Diede W M Broekaart
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Mark Luinenburg
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Caroline Mijnsbergen
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Jasper J Anink
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Nam Suk Sim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Iliana Michailidou
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Floor E Jansen
- Department of Paediatric Neurology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter C van Rijen
- Department of Neurosurgery, Brain Center, Rudolf Magnus Institute for Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,SoVarGen, Inc, Daejeon, Republic of Korea
| | - Liesbeth François
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l'Alleud, Belgium
| | - Jonathan van Eyll
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l'Alleud, Belgium
| | - Stefanie Dedeurwaerdere
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l'Alleud, Belgium.,Department of Translational Neuroscience, University of Antwerp, Wilrijk, Belgium
| | - Erwin A van Vliet
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Clinical and Experimental Epilepsy, UCL, London, UK.,Chalfont Centre for Epilepsy, Chalfont St Peter, UK
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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9
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Karalis V, Bateup HS. Current Approaches and Future Directions for the Treatment of mTORopathies. Dev Neurosci 2021; 43:143-158. [PMID: 33910214 PMCID: PMC8440338 DOI: 10.1159/000515672] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/13/2021] [Indexed: 11/19/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a kinase at the center of an evolutionarily conserved signaling pathway that orchestrates cell growth and metabolism. mTOR responds to an array of intra- and extracellular stimuli and in turn controls multiple cellular anabolic and catabolic processes. Aberrant mTOR activity is associated with numerous diseases, with particularly profound impact on the nervous system. mTOR is found in two protein complexes, mTOR complex 1 (mTORC1) and 2 (mTORC2), which are governed by different upstream regulators and have distinct cellular actions. Mutations in genes encoding for mTOR regulators result in a collection of neurodevelopmental disorders known as mTORopathies. While these disorders can affect multiple organs, neuropsychiatric conditions such as epilepsy, intellectual disability, and autism spectrum disorder have a major impact on quality of life. The neuropsychiatric aspects of mTORopathies have been particularly challenging to treat in a clinical setting. Current therapeutic approaches center on rapamycin and its analogs, drugs that are administered systemically to inhibit mTOR activity. While these drugs show some clinical efficacy, adverse side effects, incomplete suppression of mTOR targets, and lack of specificity for mTORC1 or mTORC2 may limit their utility. An increased understanding of the neurobiology of mTOR and the underlying molecular, cellular, and circuit mechanisms of mTOR-related disorders will facilitate the development of improved therapeutics. Animal models of mTORopathies have helped unravel the consequences of mTOR pathway mutations in specific brain cell types and developmental stages, revealing an array of disease-related phenotypes. In this review, we discuss current progress and potential future directions for the therapeutic treatment of mTORopathies with a focus on findings from genetic mouse models.
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Affiliation(s)
- Vasiliki Karalis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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10
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Kútna V, O'Leary VB, Newman E, Hoschl C, Ovsepian SV. Revisiting Brain Tuberous Sclerosis Complex in Rat and Human: Shared Molecular and Cellular Pathology Leads to Distinct Neurophysiological and Behavioral Phenotypes. Neurotherapeutics 2021; 18:845-858. [PMID: 33398801 PMCID: PMC8423952 DOI: 10.1007/s13311-020-01000-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2020] [Indexed: 12/27/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a dominant autosomal genetic disorder caused by loss-of-function mutations in TSC1 and TSC2, which lead to constitutive activation of the mammalian target of rapamycin C1 (mTORC1) with its decoupling from regulatory inputs. Because mTORC1 integrates an array of molecular signals controlling protein synthesis and energy metabolism, its unrestrained activation inflates cell growth and division, resulting in the development of benign tumors in the brain and other organs. In humans, brain malformations typically manifest through a range of neuropsychiatric symptoms, among which mental retardation, intellectual disabilities with signs of autism, and refractory seizures, which are the most prominent. TSC in the rat brain presents the first-rate approximation of cellular and molecular pathology of the human brain, showing many instructive characteristics. Nevertheless, the developmental profile and distribution of lesions in the rat brain, with neurophysiological and behavioral manifestation, deviate considerably from humans, raising numerous research and translational questions. In this study, we revisit brain TSC in human and Eker rats to relate their histopathological, electrophysiological, and neurobehavioral characteristics. We discuss shared and distinct aspects of the pathology and consider factors contributing to phenotypic discrepancies. Given the shared genetic cause and molecular pathology, phenotypic deviations suggest an incomplete understanding of the disease. Narrowing the knowledge gap in the future should not only improve the characterization of the TSC rat model but also explain considerable variability in the clinical manifestation of the disease in humans.
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Affiliation(s)
- Viera Kútna
- Department of Experimental Neurobiology, National Institute of Mental Health, Topolová 748, 250 67, Klecany, Czech Republic.
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine of Charles University, Ruská 87, 100 00, Prague, Czech Republic
| | - Ehren Newman
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Cyril Hoschl
- Department of Experimental Neurobiology, National Institute of Mental Health, Topolová 748, 250 67, Klecany, Czech Republic
- Department of Psychiatry and Medical Psychology, Third Faculty of Medicine of Charles University, Ruská 87, 100 00, Prague, Czech Republic
| | - Saak V Ovsepian
- Department of Experimental Neurobiology, National Institute of Mental Health, Topolová 748, 250 67, Klecany, Czech Republic.
- Department of Psychiatry and Medical Psychology, Third Faculty of Medicine of Charles University, Ruská 87, 100 00, Prague, Czech Republic.
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11
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Thomas DL, Pierson CR. Neuropathology of Surgically Managed Epilepsy Specimens. Neurosurgery 2021; 88:1-14. [PMID: 33231262 DOI: 10.1093/neuros/nyaa366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/08/2020] [Indexed: 11/14/2022] Open
Abstract
Epilepsy is characterized as recurrent seizures, and it is one of the most prevalent disorders of the human nervous system. A large and diverse profile of different syndromes and conditions can cause perturbations in neural networks that are associated with epilepsy. Advances in neuroimaging and electrophysiological monitoring have enhanced our ability to localize the neuropathological lesions that alter the neural networks giving rise to epilepsy, whereas advances in surgical management have resulted in excellent seizure control in many patients following resections. Histopathologic study using a variety of special stains, molecular analysis, and functional studies of these resected tissues has facilitated the neuropathological characterization of these lesions. Here, we review the neuropathology of common structural lesions that cause epilepsy and are amenable to neurosurgical resection, such as hippocampal sclerosis, focal cortical dysplasia, and its associated principal lesions, including long-term epilepsy-associated tumors, as well as other malformations of cortical development and Rasmussen encephalitis.
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Affiliation(s)
- Diana L Thomas
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio.,Department of Pathology, The Ohio State University, Columbus, Ohio
| | - Christopher R Pierson
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio.,Department of Pathology, The Ohio State University, Columbus, Ohio.,Division of Anatomy, Department of Biomedical Education and Anatomy, The Ohio State University, Columbus, Ohio
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12
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Wu K, Yue J, Shen K, He J, Zhu G, Liu S, Yang H, Zhang CQ. Expression and cellular distribution of FGF13 in cortical tubers of the tuberous sclerosis complex. Neurosci Lett 2021; 749:135714. [PMID: 33582188 DOI: 10.1016/j.neulet.2021.135714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 01/14/2021] [Accepted: 02/03/2021] [Indexed: 02/05/2023]
Abstract
Cortical tubers in patients with tuberous sclerosis complex (TSC) are highly associated with intractable epilepsy. Recent evidence suggests a close relationship between FGF13 and seizures. To understand the role of FGF13 in the pathogenesis of cortical tubers, we investigated the expression pattern of FGF13 in cortical tubers of TSC compared with normal control cortices (CTX). We found that both the mRNA and protein levels of FGF13 were significantly higher in the cortical tubers from patients with TSC than in the control cortices. The immunohistochemical results showed strong FGF13 immunoreactivity in abnormal cells, including dysplastic neurons (DNs) and giant cells (GCs). Moreover, double-label immunofluorescence analyses confirmed that FGF13 was mainly localized in neurons and nearly absent in glia-like cells. The protein levels of FGF13 in the TSC samples were positively correlated with the frequency of seizures before surgery. Taken together, these results suggest that the overexpression and distribution pattern of FGF13 may be related to intractable epilepsy caused by TSC.
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Affiliation(s)
- Kefu Wu
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Jiong Yue
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Kaifeng Shen
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Jiaojiang He
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Gang Zhu
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Shiyong Liu
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Hui Yang
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China.
| | - Chun-Qing Zhang
- Epilepsy Research Center of PLA, Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China.
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13
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Bongaarts A, de Jong JM, Broekaart DWM, van Scheppingen J, Anink JJ, Mijnsbergen C, Jansen FE, Spliet WGM, den Dunnen WFA, Gruber VE, Scholl T, Hainfellner JA, Feucht M, Borkowska J, Kotulska K, Jozwiak S, Grajkowska W, Buccoliero AM, Caporalini C, Giordano F, Genitori L, Scicluna BP, Schouten-van Meeteren AYN, van Vliet EA, Mühlebner A, Mills JD, Aronica E. Dysregulation of the MMP/TIMP Proteolytic System in Subependymal Giant Cell Astrocytomas in Patients With Tuberous Sclerosis Complex: Modulation of MMP by MicroRNA-320d In Vitro. J Neuropathol Exp Neurol 2020; 79:777-790. [PMID: 32472129 PMCID: PMC7304985 DOI: 10.1093/jnen/nlaa040] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/11/2020] [Accepted: 04/26/2020] [Indexed: 12/15/2022] Open
Abstract
Tuberous sclerosis complex (TSC), a rare genetic disorder caused by a mutation in the TSC1 or TSC2 gene, is characterized by the growth of hamartomas in several organs. This includes the growth of low-grade brain tumors, known as subependymal giant cell astrocytomas (SEGA). Previous studies have shown differential expression of genes related to the extracellular matrix in SEGA. Matrix metalloproteinases (MMPs), and their tissue inhibitors (TIMPs) are responsible for remodeling the extracellular matrix and are associated with tumorigenesis. This study aimed to investigate the MMP/TIMP proteolytic system in SEGA and the regulation of MMPs by microRNAs, which are important post-transcriptional regulators of gene expression. We investigated the expression of MMPs and TIMPs using previously produced RNA-Sequencing data, real-time quantitative PCR and immunohistochemistry in TSC-SEGA samples and controls. We found altered expression of several MMPs and TIMPs in SEGA compared to controls. We identified the lowly expressed miR-320d in SEGA as a potential regulator of MMPs, which can decrease MMP2 expression in human fetal astrocyte cultures. This study provides evidence of a dysregulated MMP/TIMP proteolytic system in SEGA of which MMP2 could be rescued by microRNA-320d. Therefore, further elucidating microRNA-mediated MMP regulation may provide insights into SEGA pathogenesis and identify novel therapeutic targets.
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Affiliation(s)
- Anika Bongaarts
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Jody M de Jong
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Diede W M Broekaart
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Jasper J Anink
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Caroline Mijnsbergen
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Floor E Jansen
- Department of Pediatric Neurology, University Medical Center Utrecht Brain Center, Utrecht, The Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands (WGMS); Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands (WFAdD)
| | | | - Victoria E Gruber
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Theresa Scholl
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | | | - Martha Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Julita Borkowska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Sergiusz Jozwiak
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland.,Department of Child Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Wieslawa Grajkowska
- Department of Pathology, Children's Memorial Health Institute, Warsaw, Poland
| | | | | | - Flavio Giordano
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Lorenzo Genitori
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Brendon P Scicluna
- Department of Clinical Epidemiology, Biostatistics & Bioinformatics, Center for Experimental & Molecular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam
| | - Antoinette Y N Schouten-van Meeteren
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.,Department of Pediatric Oncology, Emma Children's Hospital, Amsterdam UMC, Amsterdam, The Netherlands
| | - Erwin A van Vliet
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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14
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Zimmer TS, Broekaart DWM, Gruber VE, van Vliet EA, Mühlebner A, Aronica E. Tuberous Sclerosis Complex as Disease Model for Investigating mTOR-Related Gliopathy During Epileptogenesis. Front Neurol 2020; 11:1028. [PMID: 33041976 PMCID: PMC7527496 DOI: 10.3389/fneur.2020.01028] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis complex (TSC) represents the prototypic monogenic disorder of the mammalian target of rapamycin (mTOR) pathway dysregulation. It provides the rational mechanistic basis of a direct link between gene mutation and brain pathology (structural and functional abnormalities) associated with a complex clinical phenotype including epilepsy, autism, and intellectual disability. So far, research conducted in TSC has been largely neuron-oriented. However, the neuropathological hallmarks of TSC and other malformations of cortical development also include major morphological and functional changes in glial cells involving astrocytes, oligodendrocytes, NG2 glia, and microglia. These cells and their interglial crosstalk may offer new insights into the common neurobiological mechanisms underlying epilepsy and the complex cognitive and behavioral comorbidities that are characteristic of the spectrum of mTOR-associated neurodevelopmental disorders. This review will focus on the role of glial dysfunction, the interaction between glia related to mTOR hyperactivity, and its contribution to epileptogenesis in TSC. Moreover, we will discuss how understanding glial abnormalities in TSC might give valuable insight into the pathophysiological mechanisms that could help to develop novel therapeutic approaches for TSC or other pathologies characterized by glial dysfunction and acquired mTOR hyperactivation.
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Affiliation(s)
- Till S Zimmer
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Diede W M Broekaart
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | | | - Erwin A van Vliet
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
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15
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Gelot AB, Represa A. Progression of Fetal Brain Lesions in Tuberous Sclerosis Complex. Front Neurosci 2020; 14:899. [PMID: 32973442 PMCID: PMC7472962 DOI: 10.3389/fnins.2020.00899] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/31/2020] [Indexed: 11/24/2022] Open
Abstract
Tuberous sclerosis (TSC) is a multisystem autosomal dominant genetic disorder due to loss of function of TSC1/TSC2 resulting in increased mTOR (mammalian target of rapamycin) signaling. In the brain, TSC is characterized by the formation of specific lesions that include subependymal and white matter nodules and cortical tubers. Cells that constitute TSC lesions are mainly Giant cells and dysmorphic neurons and astrocytes, but normal cells also populate the tubers. Although considered as a developmental disorder, the histopathological features of brain lesions have been described in only a limited number of fetal cases, providing little information on how these lesions develop. In this report we characterized the development of TSC lesions in 14 fetal brains ranging from 19 gestational weeks (GW) to term and 2 postnatal cases. The study focused on the telencephalon at the level of the caudothalamic notch. Our data indicate that subcortical lesions, forming within and at the vicinity of germinative zones, are the first alterations (already detected in 19GW brains), characterized by the presence of numerous dysmorphic astrocytes and Giant, balloon-like, cells. Our data show that cortical tuber formation is a long process that initiates with the presence of dysmorphic astrocytes (by 19–21GW), progress with the apparition of Giant cells (by 24GW) and mature with the appearance of dysmorphic neurons by the end of gestation (by 36GW). Furthermore, the typical tuberal aspect of cortical lesions is only reached when bundles of neurofilament positive extensions delineate the bottom of the cortical lesion (by 36GW). In addition, our study reveals the presence of Giant cells and dysmorphic neurons immunopositive for interneuron markers such as calbindin and parvalbumin, suggesting that TSC lesions would be mosaic lesions generated from different classes of progenitors.
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Affiliation(s)
- Antoinette Bernabe Gelot
- Aix-Marseille University, INSERM, INMED, Marseille, France.,APHP, Hôpital Trousseau, Université Pierre et Marie Curie, Paris, France
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16
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Glioneuronal Hamartomas in the Central Nervous System of Two Goats. J Comp Pathol 2020; 178:10-15. [PMID: 32800102 DOI: 10.1016/j.jcpa.2020.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/22/2020] [Accepted: 06/10/2020] [Indexed: 11/21/2022]
Abstract
Two goats (6 months old and 5 years old) were evaluated for neurological signs including laboured breathing, stiffness and obtundation. Solitary masses were noted in the brainstem and spinal cord, respectively. Histopathology of both cases revealed the lesions were composed of a mixture of glial and neuronal cells, consistent with glioneuronal hamartomas. The cause of death was attributed to the mass in the 6-month-old, while the cause of death in the 5-year-old was attributed to listeriosis. Hamartomas of neural origin are rarely described in veterinary species, and this report represents the first report of glioneuronal hamartomas in goats.
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17
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Feliciano DM. The Neurodevelopmental Pathogenesis of Tuberous Sclerosis Complex (TSC). Front Neuroanat 2020; 14:39. [PMID: 32765227 PMCID: PMC7381175 DOI: 10.3389/fnana.2020.00039] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a model disorder for understanding brain development because the genes that cause TSC are known, many downstream molecular pathways have been identified, and the resulting perturbations of cellular events are established. TSC, therefore, provides an intellectual framework to understand the molecular and biochemical pathways that orchestrate normal brain development. The TSC1 and TSC2 genes encode Hamartin and Tuberin which form a GTPase activating protein (GAP) complex. Inactivating mutations in TSC genes (TSC1/TSC2) cause sustained Ras homologue enriched in brain (RHEB) activation of the mammalian isoform of the target of rapamycin complex 1 (mTORC1). TOR is a protein kinase that regulates cell size in many organisms throughout nature. mTORC1 inhibits catabolic processes including autophagy and activates anabolic processes including mRNA translation. mTORC1 regulation is achieved through two main upstream mechanisms. The first mechanism is regulation by growth factor signaling. The second mechanism is regulation by amino acids. Gene mutations that cause too much or too little mTORC1 activity lead to a spectrum of neuroanatomical changes ranging from altered brain size (micro and macrocephaly) to cortical malformations to Type I neoplasias. Because somatic mutations often underlie these changes, the timing, and location of mutation results in focal brain malformations. These mutations, therefore, provide gain-of-function and loss-of-function changes that are a powerful tool to assess the events that have gone awry during development and to determine their functional physiological consequences. Knowledge about the TSC-mTORC1 pathway has allowed scientists to predict which upstream and downstream mutations should cause commensurate neuroanatomical changes. Indeed, many of these predictions have now been clinically validated. A description of clinical imaging and histochemical findings is provided in relation to laboratory models of TSC that will allow the reader to appreciate how human pathology can provide an understanding of the fundamental mechanisms of development.
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Affiliation(s)
- David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, United States
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18
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KARALÖK ZS, GÜVEN A, ALTAN H, ÖZTÜRK Z, CEYLAN N, GÜRKAŞ E. Tüberoskleroz kompleksi tanılı hastaların değerlendirilmesi. ACTA MEDICA ALANYA 2020. [DOI: 10.30565/medalanya.584167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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19
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Afshar Saber W, Sahin M. Recent advances in human stem cell-based modeling of Tuberous Sclerosis Complex. Mol Autism 2020; 11:16. [PMID: 32075691 PMCID: PMC7031912 DOI: 10.1186/s13229-020-0320-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by epilepsy, intellectual disability, and benign tumors of the brain, heart, skin, and kidney. Animal models have contributed to our understanding of normal and abnormal human brain development, but the construction of models that accurately recapitulate a human pathology remains challenging. Recent advances in stem cell biology with the derivation of human-induced pluripotent stem cells (hiPSCs) from somatic cells from patients have opened new avenues to the study of TSC. This approach combined with gene-editing tools such as CRISPR/Cas9 offers the advantage of preserving patient-specific genetic background and the ability to generate isogenic controls by correcting a specific mutation. The patient cell line and the isogenic control can be differentiated into the cell type of interest to model various aspects of TSC. In this review, we discuss the remarkable capacity of these cells to be used as a model for TSC in two- and three-dimensional cultures, the potential variability in iPSC models, and highlight differences between findings reported to date.
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Affiliation(s)
- Wardiya Afshar Saber
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Mustafa Sahin
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA.
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20
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Bongaarts A, van Scheppingen J, Korotkov A, Mijnsbergen C, Anink JJ, Jansen FE, Spliet WGM, den Dunnen WFA, Gruber VE, Scholl T, Samueli S, Hainfellner JA, Feucht M, Kotulska K, Jozwiak S, Grajkowska W, Buccoliero AM, Caporalini C, Giordano F, Genitori L, Coras R, Blümcke I, Krsek P, Zamecnik J, Meijer L, Scicluna BP, Schouten-van Meeteren AYN, Mühlebner A, Mills JD, Aronica E. The coding and non-coding transcriptional landscape of subependymal giant cell astrocytomas. Brain 2020; 143:131-149. [PMID: 31834371 PMCID: PMC6935755 DOI: 10.1093/brain/awz370] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/13/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited neurocutaneous disorder caused by inactivating mutations in TSC1 or TSC2, key regulators of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. In the CNS, TSC is characterized by cortical tubers, subependymal nodules and subependymal giant cell astrocytomas (SEGAs). SEGAs may lead to impaired circulation of CSF resulting in hydrocephalus and raised intracranial pressure in patients with TSC. Currently, surgical resection and mTORC1 inhibitors are the recommended treatment options for patients with SEGA. In the present study, high-throughput RNA-sequencing (SEGAs n = 19, periventricular control n = 8) was used in combination with computational approaches to unravel the complexity of SEGA development. We identified 9400 mRNAs and 94 microRNAs differentially expressed in SEGAs compared to control tissue. The SEGA transcriptome profile was enriched for the mitogen-activated protein kinase (MAPK) pathway, a major regulator of cell proliferation and survival. Analysis at the protein level confirmed that extracellular signal-regulated kinase (ERK) is activated in SEGAs. Subsequently, the inhibition of ERK independently of mTORC1 blockade decreased efficiently the proliferation of primary patient-derived SEGA cultures. Furthermore, we found that LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5 were overexpressed at both gene and protein levels in SEGA compared to control tissue. Taken together LAMTOR1-5 can form a complex, known as the 'Ragulator' complex, which is known to activate both mTORC1 and MAPK/ERK pathways. Overall, this study shows that the MAPK/ERK pathway could be used as a target for treatment independent of, or in combination with mTORC1 inhibitors for TSC patients. Moreover, our study provides initial evidence of a possible link between the constitutive activated mTORC1 pathway and a secondary driver pathway of tumour growth.
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Affiliation(s)
- Anika Bongaarts
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Anatoly Korotkov
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Caroline Mijnsbergen
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jasper J Anink
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Floor E Jansen
- Department of Pediatric Neurology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wilfred F A den Dunnen
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Victoria E Gruber
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Theresa Scholl
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Sharon Samueli
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | | | - Martha Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Sergiusz Jozwiak
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
- Department of Child Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Wieslawa Grajkowska
- Department of Pathology, Children's Memorial Health Institute, Warsaw, Poland
| | | | | | - Flavio Giordano
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Lorenzo Genitori
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Pavel Krsek
- Department of Paediatric 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
| | - Lisethe Meijer
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Brendon P Scicluna
- Center for Experimental and Molecular Medicine and Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Antoinette Y N Schouten-van Meeteren
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pediatric Oncology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
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21
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Costamagna G, Andreoli L, Corti S, Faravelli I. iPSCs-Based Neural 3D Systems: A Multidimensional Approach for Disease Modeling and Drug Discovery. Cells 2019; 8:E1438. [PMID: 31739555 PMCID: PMC6912470 DOI: 10.3390/cells8111438] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/26/2019] [Accepted: 11/11/2019] [Indexed: 02/06/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs)-based two-dimensional (2D) protocols have offered invaluable insights into the pathophysiology of neurological diseases. However, these systems are unable to reproduce complex cytoarchitectural features, cell-cell and tissue-tissue interactions like their in vivo counterpart. Three-dimensional (3D)-based culture protocols, though in their infancy, have offered new insights into modeling human diseases. Human neural organoids try to recapitulate the cellular diversity of complex tissues and can be generated from iPSCs to model the pathophysiology of a wide spectrum of pathologies. The engraftment of iPSCs into mice models and the improvement of differentiation protocols towards 3D cultures has enabled the generation of more complex multicellular systems. Consequently, models of neuropsychiatric disorders, infectious diseases, brain cancer and cerebral hypoxic injury can now be investigated from new perspectives. In this review, we consider the advancements made in modeling neuropsychiatric and neurological diseases with iPSC-derived organoids and their potential use to develop new drugs.
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Affiliation(s)
| | | | | | - Irene Faravelli
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (G.C.); (L.A.); (S.C.)
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22
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Blair JD, Bateup HS. New frontiers in modeling tuberous sclerosis with human stem cell-derived neurons and brain organoids. Dev Dyn 2019; 249:46-55. [PMID: 31070828 DOI: 10.1002/dvdy.60] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/01/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022] Open
Abstract
Recent advances in human stem cell and genome engineering have enabled the generation of genetically defined human cellular models for brain disorders. These models can be established from a patient's own cells and can be genetically engineered to generate isogenic, controlled systems for mechanistic studies. Given the challenges of obtaining and working with primary human brain tissue, these models fill a critical gap in our understanding of normal and abnormal human brain development and provide an important complement to animal models. Recently, there has been major progress in modeling the neuropathophysiology of the canonical "mTORopathy" tuberous sclerosis complex (TSC) with such approaches. Studies using two- and three-dimensional cultures of human neurons and glia have provided new insights into how mutations in the TSC1 and TSC2 genes impact human neural development and function. Here we discuss recent progress in human stem cell-based modeling of TSC and highlight challenges and opportunities for further efforts in this area.
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Affiliation(s)
- John D Blair
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, California.,Helen Wills Neuroscience Institute, University of California, Berkeley, California.,Chan Zuckerberg Biohub, San Francisco, California
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23
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Sarff B, Floyd R, Bildner A, Stormo J, Fisher K. Fetal Echocardiographic Detection of Cardiac Tumors: A Case Report of Multiple Fetal Cardiac Rhabdomyomas. JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY 2019. [DOI: 10.1177/8756479319847641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac rhabdomyomas are the most common fetal cardiac tumor. They can be detected in the second and third trimesters. Rhabdomyomas are most commonly associated with the genetic disorder tuberous sclerosis complex. When associated with tuberous sclerosis complex, cardiac rhabdomyomas usually regress within the first few years of life, without complications. Symptoms depend on the size, number, and location of the rhabdomyomas. A case report of multiple cardiac rhabdomyomas that was found at 35 weeks’ gestation and is discussed.
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Affiliation(s)
- Bailey Sarff
- Diagnostic Medical Ultrasound Program, University of Missouri, Columbia, MO, USA
| | - Randall Floyd
- Diagnostic Medical Ultrasound Program, University of Missouri, Columbia, MO, USA
| | - Amy Bildner
- Diagnostic Medical Ultrasound Program, University of Missouri, Columbia, MO, USA
| | - Janell Stormo
- Diagnostic Medical Ultrasound Program, University of Missouri, Columbia, MO, USA
| | - Kelsy Fisher
- Diagnostic Medical Ultrasound Program, University of Missouri, Columbia, MO, USA
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24
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Molecular genetics and therapeutic targets of pediatric low-grade gliomas. Brain Tumor Pathol 2019; 36:74-83. [PMID: 30929113 DOI: 10.1007/s10014-019-00340-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/19/2019] [Indexed: 12/27/2022]
Abstract
Pediatric low-grade gliomas (PLGGs) have relatively favorable prognosis and some resectable PLGGs, such as cerebellar pilocytic astrocytoma, can be cured by surgery alone. However, many PLGG cases are unresectable and some of them undergo tumor progression. Therefore, a multidisciplinary approach is necessary to treat PLGG patients. Recent genomic analysis revealed a broad genomic landscape underlying PLGG. Notably, the majority of PLGGs present MAPK pathway-associated genomic alterations and MAPK signaling-dependent tumor progression. Following preclinical evidence, many clinical trials based on molecular target therapy have been conducted on PLGG patients, some of whom exhibited durable response to target therapy. Here, we provide an overview of PLGG genetics and the evidence supporting the application of molecular target therapy in these patients.
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25
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Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
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Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
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26
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Factors affecting epilepsy prognosis in patients with tuberous sclerosis. Childs Nerv Syst 2019; 35:463-468. [PMID: 30673834 DOI: 10.1007/s00381-019-04066-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/16/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE We aimed to determine the characteristics of epileptic seizures that significantly affect the cognitive functions of 83 patients followed with tuberous sclerosis complex (TSC), their resistance to treatment and risk factors causing this resistance. MATERIALS-METHODS In order to determine the prognosis, the seizure-free/seizure-controlled group and the group with refractory seizures were compared. In addition, risk factors affecting cognitive functions in the patients were determined. RESULTS There was a statistical significance between the presence of a history of seizures in the neonatal period, the age of onset of seizures being less than 2 years of age, autism, status epilepticus, Lennox-Gastaut syndrome (LGS), presence of infantile spasm, generalization of the electroencephalography (EEG) findings, the number of tubers in cerebral imaging being more than three and refractory seizures (p < 0.05). Statistically significant relationship was found between presence of a history of seizures in the neonatal period, the age of onset of seizures, autism, LGS, presence of infantile spasm, presence of status epilepticus history, history of using more than three antiepileptic drugs, generalization of EEG findings, presence of SEGA in cerebral imaging, number of tubers being more than three and the patient's mental retardation (p < 0.05). CONCLUSION In logistic regression analysis, the age of the seizure onset being less than 2 years of age, the presence of autism and number of tubers being more than three in cerebral magnetic resonance imaging (MRI) are determined to be the risk factors that most likely to increase the seizures to be more resistant.
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27
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Azriel A, Gogos A, Rogers T, Moscovici S, Lo P, Drummond K. Glioblastoma in a patient with tuberous sclerosis. J Clin Neurosci 2018; 60:153-155. [PMID: 30528355 DOI: 10.1016/j.jocn.2018.10.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/14/2018] [Indexed: 11/16/2022]
Abstract
Tuberous sclerosis complex (TSC) is a multisystem, autosomal dominant disorder with a wide clinical spectrum. The most common brain tumor associated with TSC is the low grade subependymal giant cell astrocytoma. Reports of high grade primary brain tumors in patients with TSC are rare. TSC1/2 mutation has been identified in glioblastoma (GBM) even though it probably does not increase the overall risk for GBM in patients with TSC. We present a 58-year-old patient with known TSC, admitted for new neurological symptoms, diagnosed with a large heterogeneous tumor involving most of the corpus callosum. Stereotactic needle brain biopsy confirmed the diagnosis to be GBM. Five previously reported similar cases are reviewed, reflecting diversity in clinical and radiological findings and indicating that a high index of clinical suspicion must be maintained in patients with TSC.
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Affiliation(s)
- Amit Azriel
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Surgery, The University of Melbourne, Parkville, Victoria, Australia.
| | - Andrew Gogos
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Surgery, The University of Melbourne, Parkville, Victoria, Australia
| | - TeWhiti Rogers
- Department of Pathology, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Samuel Moscovici
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Surgery, The University of Melbourne, Parkville, Victoria, Australia
| | - Patrick Lo
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Katharine Drummond
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Surgery, The University of Melbourne, Parkville, Victoria, Australia
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28
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Brigo F, Lattanzi S, Trinka E, Nardone R, Bragazzi NL, Ruggieri M, Martini M, Walusinski O. First descriptions of tuberous sclerosis by Désiré-Magloire Bourneville (1840-1909). Neuropathology 2018; 38:577-582. [PMID: 30215888 DOI: 10.1111/neup.12515] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Francesco Brigo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,Division of Neurology, "Franz Tappeiner" Hospital, Merano, Italy
| | - Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.,Center for Cognitive Neuroscience, Salzburg, Austria.,Public Health, Health Services Research and HTA, University for Health Sciences, Medical Informatics and Technology, Hall i.T, Austria
| | - Raffaele Nardone
- Division of Neurology, "Franz Tappeiner" Hospital, Merano, Italy.,Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria
| | - Nicola L Bragazzi
- Department of Health Sciences (DISSAL), School of Public Health, University of Genoa, Genoa, Italy
| | - Martino Ruggieri
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, AOU "Policlinico-Vittorio Emanuele", University of Catania, Catania, Italy
| | - Mariano Martini
- Department of Clinical and Experimental Medicine, Section of History of Medicine, University of Catania, Catania, Italy.,Department of Health Sciences, Section of Medical History and Ethics, University of Genoa, Genoa, Italy.,Unesco Chair "Anthropology of Health-Biosphere and Healing System", University of Genoa, Genoa, Italy
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29
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Regionally specific TSC1 and TSC2 gene expression in tuberous sclerosis complex. Sci Rep 2018; 8:13373. [PMID: 30190613 PMCID: PMC6127129 DOI: 10.1038/s41598-018-31075-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 08/06/2018] [Indexed: 12/15/2022] Open
Abstract
Tuberous sclerosis complex (TSC), a heritable neurodevelopmental disorder, is caused by mutations in the TSC1 or TSC2 genes. To date, there has been little work to elucidate regional TSC1 and TSC2 gene expression within the human brain, how it changes with age, and how it may influence disease. Using a publicly available microarray dataset, we found that TSC1 and TSC2 gene expression was highest within the adult neo-cerebellum and that this pattern of increased cerebellar expression was maintained throughout postnatal development. During mid-gestational fetal development, however, TSC1 and TSC2 expression was highest in the cortical plate. Using a bioinformatics approach to explore protein and genetic interactions, we confirmed extensive connections between TSC1/TSC2 and the other genes that comprise the mammalian target of rapamycin (mTOR) pathway, and show that the mTOR pathway genes with the highest connectivity are also selectively expressed within the cerebellum. Finally, compared to age-matched controls, we found increased cerebellar volumes in pediatric TSC patients without current exposure to antiepileptic drugs. Considered together, these findings suggest that the cerebellum may play a central role in TSC pathogenesis and may contribute to the cognitive impairment, including the high incidence of autism spectrum disorder, observed in the TSC population.
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30
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Blair JD, Hockemeyer D, Bateup HS. Genetically engineered human cortical spheroid models of tuberous sclerosis. Nat Med 2018; 24:1568-1578. [PMID: 30127391 PMCID: PMC6261470 DOI: 10.1038/s41591-018-0139-y] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/06/2018] [Indexed: 01/01/2023]
Abstract
Tuberous sclerosis complex (TSC) is a multisystem developmental disorder caused by mutations in the TSC1 or TSC2 genes, whose protein products are negative regulators of mechanistic target of rapamycin complex 1 signaling. Hallmark pathologies of TSC are cortical tubers-regions of dysmorphic, disorganized neurons and glia in the cortex that are linked to epileptogenesis. To determine the developmental origin of tuber cells, we established human cellular models of TSC by CRISPR-Cas9-mediated gene editing of TSC1 or TSC2 in human pluripotent stem cells (hPSCs). Using heterozygous TSC2 hPSCs with a conditional mutation in the functional allele, we show that mosaic biallelic inactivation during neural progenitor expansion is necessary for the formation of dysplastic cells and increased glia production in three-dimensional cortical spheroids. Our findings provide support for the second-hit model of cortical tuber formation and suggest that variable developmental timing of somatic mutations could contribute to the heterogeneity in the neurological presentation of TSC.
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Affiliation(s)
- John D Blair
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA. .,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
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31
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Abstract
RATIONALE Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder. The TSC1 and TSC2 genes have been identified as pathogenic genes. PATIENT CONCERNS In this report, we are discussing a novel frameshift mutation and a novel missense mutation in the TSC2 gene. DIAGNOSES The two cases discussed in this study met the latest diagnostic criteria for TSC published by the International Tuberculosis Sclerosis Complex Consensus Conference in 2012. INTERVENTIONS High-throughput sequencing and multiplex ligation-dependent probe amplification (MLPA) were used to examine tuberous sclerosis complex (TSC)-related genes (TSC1 and TSC2) and their splicing regions using peripheral blood DNA from two probands in two families with TSC and to identify the genetic mutation sites. Amplification primers were designed for the mutation sites, and polymerase chain reaction and Sanger sequencing were used to verify the peripheral blood DNA sequences from the probands and their parents. OUTCOME Proband 1 had the c.1228 (exon 12)_c.1229 (exon 12) insG (p.L410RfsX11) heterozygous mutation in the TSC2 gene (chr16), which was a new frameshift mutation. Proband 2 had the c.4925G>A (exon 38) (p.G1642D) heterozygous mutation in the TSC2 gene (chr16), which was a new missense mutation. LESSONS These two novel mutations may be pathogenic mutations for TSC, and their association with the disease needs to be further verified by mutant protein function cell model and animal model.
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Affiliation(s)
- Shan Gao
- Department of Pediatric Neurology and Gastroenterology, West China Second University Hospital
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, P.R. China
| | - Zhiling Wang
- Department of Pediatric Neurology and Gastroenterology, West China Second University Hospital
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, P.R. China
| | - Yongmei Xie
- Department of Pediatric Neurology and Gastroenterology, West China Second University Hospital
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, P.R. China
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Srivastava S, Prohl AK, Scherrer B, Kapur K, Krueger DA, Warfield SK, Sahin M. Cerebellar volume as an imaging marker of development in infants with tuberous sclerosis complex. Neurology 2018; 90:e1493-e1500. [PMID: 29572283 PMCID: PMC5921037 DOI: 10.1212/wnl.0000000000005352] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/25/2018] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE In this cohort analysis, we studied 1-year-old infants with tuberous sclerosis complex (TSC), correlating volumes of cerebellar structures with neurodevelopmental measures. METHODS We analyzed data from a prospective biomarker study in infants with TSC (ClinicalTrials.gov NCT01780441). We included participants aged 12 months with an identified mutation of TSC1 or TSC2. Using MRI segmentation performed with the PSTAPLE algorithm, we measured relative volumes (structure volume divided by intracranial contents volume) of the following structures: right/left cerebellar white matter, right/left cerebellar exterior, vermal lobules I-V, vermal lobules VI-VII, and vermal lobules VIII-X. We correlated relative volumes to Mullen Scales of Early Learning (MSEL) scores. RESULTS There were 70 participants (mean age 1.03 [0.11] years): n = 11 had a TSC1 mutation; n = 59 had a TSC2 mutation. For patients with TSC2 mutation, for every percentage increase in total cerebellar volume, there was an approximate 10-point increase in MSEL composite score (β = 10.47 [95% confidence interval 5.67, 15.27], p < 0.001). For patients with TSC1 mutation, the relationship between cerebellar volume and MSEL composite score was not statistically significant (β = -10.88 [95% confidence interval -22.16, 0.41], p = 0.06). For patients with TSC2 mutation, there were positive slopes when regressing expressive language and visual reception skills with volumes of nearly all cerebellar structures (p ≤ 0.29); there were also positive slopes when regressing receptive language skills, gross motor skills, and fine motor skills with volumes of cerebellar right/left exterior (p ≤ 0.014). CONCLUSIONS Cerebellar volume loss-perhaps reflecting Purkinje cell degeneration-may predict neurodevelopmental severity in patients with TSC2 mutations.
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Affiliation(s)
- Siddharth Srivastava
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Anna K Prohl
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Benoit Scherrer
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Kush Kapur
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Darcy A Krueger
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Simon K Warfield
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH
| | - Mustafa Sahin
- From the Departments of Neurology (S.S., K.K., M.S.) and Radiology (A.K.P., B.S., S.K.W.), Boston Children's Hospital, Harvard Medical School, Boston, MA; and Department of Pediatrics (D.A.K.), Division of Neurology, Cincinnati Children's Hospital Medical Center, OH.
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33
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Kielbinski M, Gzielo K, Soltys Z. Review: Roles for astrocytes in epilepsy: insights from malformations of cortical development. Neuropathol Appl Neurobiol 2018; 42:593-606. [PMID: 27257021 DOI: 10.1111/nan.12331] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/25/2016] [Accepted: 06/03/2016] [Indexed: 12/25/2022]
Abstract
Malformations of cortical development (MCDs), such as cortical dysplasia and tuberous sclerosis complex, are common causes of intractable epilepsy, especially in paediatric patients. Recently, mounting evidence points to a common pathology of these disorders. Hyperactivation of mammalian target of rapamycin (mTOR) has been proposed as a central mechanism in most, if not all, MCDs. The transition from mTOR hyperactivation and cellular abnormalities to large-scale functional changes and seizure is, however, not fully understood. In this article we set out to review currently available information regarding MCD pathology, focusing on glial cells - especially astrocytes - and their interactions with the brain vascular system. A large body of evidence points to these elements as potential targets in MCD. Here, we attempt to provide a review of this evidence and propose some hypotheses regarding the possible chain of events linking primary glial dysfunction and epilepsy. We focus on extracellular matrix remodelling, blood-brain barrier leakage and failure of astrocyte-dependent removal of extracellular debris. We posit that the failure of these systems results in a chronically pro-inflammatory environment, maintaining local astrocytes in a state of gliosis, with increased susceptibility to seizures as a consequence.
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Affiliation(s)
- M Kielbinski
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - K Gzielo
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - Z Soltys
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
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Curatolo P, Moavero R, van Scheppingen J, Aronica E. mTOR dysregulation and tuberous sclerosis-related epilepsy. Expert Rev Neurother 2018; 18:185-201. [DOI: 10.1080/14737175.2018.1428562] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
| | - Romina Moavero
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
- Child Neurology Unit, Neuroscience and Neurorehabilitation Department, “Bambino Gesù” Children’s Hospital, IRCCS, Rome, Italy
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
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Jeong A, Wong M. Targeting the Mammalian Target of Rapamycin for Epileptic Encephalopathies and Malformations of Cortical Development. J Child Neurol 2018; 33:55-63. [PMID: 29246093 PMCID: PMC5739082 DOI: 10.1177/0883073817696814] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Malformations of cortical development represent a common cause of epileptic encephalopathies and drug-resistant epilepsy in children. As current treatments are often ineffective, new therapeutic targets are needed for epileptic encephalopathies associated with cortical malformations. The mechanistic/mammalian target of rapamycin (mTOR) pathway constitutes a signaling pathway that drives cellular and molecular mechanisms of epileptogenesis in a variety of focal cortical malformations. mTOR inhibitors prevent epilepsy and associated pathogenic mechanisms of epileptogenesis in mouse models of tuberous sclerosis complex and are currently in clinical trials for drug-resistant seizures in these patients. A recent explosion of genetic studies has linked mutations in various genes regulating the mTOR pathway to other cortical malformations, such as focal cortical dysplasia and hemimegalencephaly. Thus, mTOR inhibitors represent promising candidates as novel antiseizure and antiepileptogenic therapies for epilepsy associated with a spectrum of cortical malformations.
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Affiliation(s)
- Anna Jeong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
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Mao S, Long Q, Lin H, Liu J. Rapamycin therapy for neonatal tuberous sclerosis complex with cardiac rhabdomyomas: A case report and review. Exp Ther Med 2017; 14:6159-6163. [PMID: 29285173 PMCID: PMC5740740 DOI: 10.3892/etm.2017.5335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 07/11/2017] [Indexed: 11/19/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disease that varies greatly in its expression. The current study reports a novel case of TSC caused by a TSC2 mutation (TSC2c.1642_1643insA or TSC2p.K549fsX589), in which multiple cardiac rhabdomyomas were detected by fetal echocardiography in week 31 of pregnancy. The infant was delivered successfully; however, seizures began 16 days following birth. Subsequent genetic tests confirmed a diagnosis of TSC. Rapamycin treatment resulted in regression of cardiac rhabdomyomas and controlled seizures. The current study demonstrates the value of fetal echocardiography in the diagnosis of TSC and suggests that inhibition of the mammalian target of the rapamycin (mTOR) signaling pathway may be considered as a potential antiepileptogenic therapy for neonatal TSC. In addition, it was demonstrated that rapamycin treatment was therapeutically beneficial for preventing disorders caused by abnormal mTOR signaling, such as cancer. According to the literature, cardiac rhabdomyomas, seizures and skin lesions are well established markers for TSC in neonates. MRI scans of the brain and genetic screening of TSC1 and TSC2 genes may facilitate an early diagnosis of TSC.
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Affiliation(s)
- Shanshan Mao
- Department of Neurology, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, P.R. China
| | - Qi Long
- Department of Clinical Nutrition, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, P.R. China
| | - Huijia Lin
- Department of Neonatology, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, P.R. China
| | - Jinling Liu
- Department of Pulmonology, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, P.R. China
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Bongaarts A, Giannikou K, Reinten RJ, Anink JJ, Mills JD, Jansen FE, Spliet GW, den Dunnen WF, Coras R, Blümcke I, Paulus W, Scholl T, Feucht M, Kotulska K, Jozwiak S, Buccoliero AM, Caporalini C, Giordano F, Genitori L, Söylemezoğlu F, Pimentel J, Nellist M, Schouten-van Meeteren AY, Nag A, Mühlebner A, Kwiatkowski DJ, Aronica E. Subependymal giant cell astrocytomas in Tuberous Sclerosis Complex have consistent TSC1/TSC2 biallelic inactivation, and no BRAF mutations. Oncotarget 2017; 8:95516-95529. [PMID: 29221145 PMCID: PMC5707039 DOI: 10.18632/oncotarget.20764] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/31/2017] [Indexed: 12/12/2022] Open
Abstract
Subependymal giant cell astrocytomas (SEGAs) are rare, low-grade glioneuronal brain tumors that occur almost exclusively in patients with tuberous sclerosis complex (TSC). Though histologically benign, SEGAs can lead to serious neurological complications, including hydrocephalus, intractable seizures and death. Previous studies in a limited number of SEGAs have provided evidence for a biallelic two-hit inactivation of either TSC1 or TSC2, resulting in constitutive activation of the mechanistic target of rapamycin complex 1 pathway. The activating BRAF V600E mutation is a common genetic alteration in low grade gliomas and glioneuronal tumors, and has been reported in SEGAs as well. In the present study, we assessed the prevalence of the BRAF V600E mutation in a large cohort of TSC related SEGAs (n=58 patients including 56 with clinical TSC) and found no evidence of either BRAF V600E or other mutations in BRAF. To confirm that these SEGAs fit the classic model of two hit TSC1 or TSC2 inactivation, we also performed massively parallel sequencing of these loci. Nineteen (19) of 34 (56%) samples had mutations in TSC2, 10 (29%) had mutations in TSC1, while 5 (15%) had no mutation identified in TSC1/TSC2. The majority of these samples had loss of heterozygosity in the same gene in which the mutation was identified. These results significantly extend previous studies, and in agreement with the Knudson two hit mechanism indicate that biallelic alterations in TSC2 and less commonly, TSC1 are consistently seen in SEGAs.
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Affiliation(s)
- Anika Bongaarts
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Krinio Giannikou
- Division of Pulmonary and Critical Care Medicine and of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Roy J. Reinten
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jasper J. Anink
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - James D. Mills
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Floor E. Jansen
- Department of Pediatric Neurology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - G.M Wim Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Willfred F.A. den Dunnen
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Werner Paulus
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - Theresa Scholl
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Martha Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Sergiusz Jozwiak
- Department of Child Neurology, Medical University of Warsaw, Warsaw, Poland
| | | | | | - Flavio Giordano
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Lorenzo Genitori
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - Figen Söylemezoğlu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - José Pimentel
- Department of Neurology, Hospital de Santa Maria, Lisbon, Portugal
| | - Mark Nellist
- Department of Clinical Genetics, Erasmus Medical Centre, Rotterdam, The Netherlands
| | | | - Anwesha Nag
- Center for Cancer Genome Discovery, Dana Farber Cancer Institute, Boston, Massachusetts, USA
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - David J. Kwiatkowski
- Division of Pulmonary and Critical Care Medicine and of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
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Varghese M, Keshav N, Jacot-Descombes S, Warda T, Wicinski B, Dickstein DL, Harony-Nicolas H, De Rubeis S, Drapeau E, Buxbaum JD, Hof PR. Autism spectrum disorder: neuropathology and animal models. Acta Neuropathol 2017; 134:537-566. [PMID: 28584888 PMCID: PMC5693718 DOI: 10.1007/s00401-017-1736-4] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorder (ASD) has a major impact on the development and social integration of affected individuals and is the most heritable of psychiatric disorders. An increase in the incidence of ASD cases has prompted a surge in research efforts on the underlying neuropathologic processes. We present an overview of current findings in neuropathology studies of ASD using two investigational approaches, postmortem human brains and ASD animal models, and discuss the overlap, limitations, and significance of each. Postmortem examination of ASD brains has revealed global changes including disorganized gray and white matter, increased number of neurons, decreased volume of neuronal soma, and increased neuropil, the last reflecting changes in densities of dendritic spines, cerebral vasculature and glia. Both cortical and non-cortical areas show region-specific abnormalities in neuronal morphology and cytoarchitectural organization, with consistent findings reported from the prefrontal cortex, fusiform gyrus, frontoinsular cortex, cingulate cortex, hippocampus, amygdala, cerebellum and brainstem. The paucity of postmortem human studies linking neuropathology to the underlying etiology has been partly addressed using animal models to explore the impact of genetic and non-genetic factors clinically relevant for the ASD phenotype. Genetically modified models include those based on well-studied monogenic ASD genes (NLGN3, NLGN4, NRXN1, CNTNAP2, SHANK3, MECP2, FMR1, TSC1/2), emerging risk genes (CHD8, SCN2A, SYNGAP1, ARID1B, GRIN2B, DSCAM, TBR1), and copy number variants (15q11-q13 deletion, 15q13.3 microdeletion, 15q11-13 duplication, 16p11.2 deletion and duplication, 22q11.2 deletion). Models of idiopathic ASD include inbred rodent strains that mimic ASD behaviors as well as models developed by environmental interventions such as prenatal exposure to sodium valproate, maternal autoantibodies, and maternal immune activation. In addition to replicating some of the neuropathologic features seen in postmortem studies, a common finding in several animal models of ASD is altered density of dendritic spines, with the direction of the change depending on the specific genetic modification, age and brain region. Overall, postmortem neuropathologic studies with larger sample sizes representative of the various ASD risk genes and diverse clinical phenotypes are warranted to clarify putative etiopathogenic pathways further and to promote the emergence of clinically relevant diagnostic and therapeutic tools. In addition, as genetic alterations may render certain individuals more vulnerable to developing the pathological changes at the synapse underlying the behavioral manifestations of ASD, neuropathologic investigation using genetically modified animal models will help to improve our understanding of the disease mechanisms and enhance the development of targeted treatments.
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Affiliation(s)
- Merina Varghese
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Neha Keshav
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Sarah Jacot-Descombes
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Unit of Psychiatry, Department of Children and Teenagers, University Hospitals and School of Medicine, Geneva, CH-1205, Switzerland
| | - Tahia Warda
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Bridget Wicinski
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dara L Dickstein
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Hala Harony-Nicolas
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Silvia De Rubeis
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Elodie Drapeau
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joseph D Buxbaum
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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RHEB1 insufficiency in aged male mice is associated with stress-induced seizures. GeroScience 2017; 39:557-570. [PMID: 28891034 DOI: 10.1007/s11357-017-9997-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/24/2017] [Indexed: 02/06/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR), a protein kinase, is a central regulator of mammalian metabolism and physiology. Protein mTOR complex 1 (mTORC1) functions as a major sensor for the nutrient, energy, and redox state of a cell and is activated by ras homolog enriched in brain (RHEB1), a GTP-binding protein. Increased activation of mTORC1 pathway has been associated with developmental abnormalities, certain form of epilepsy (tuberous sclerosis), and cancer. Clinically, those mTOR-related disorders are treated with the mTOR inhibitor rapamycin and its rapalogs. Because the effects of chronic interference with mTOR signaling in the aged brain are yet unknown, we used a genetic strategy to interfere with mTORC1 signaling selectively by introducing mutations of Rheb1 into the mouse. We created conventional knockout (Rheb1 +/- ) and gene trap (Rheb1 Δ/+ ) mutant mouse lines. Rheb1-insufficient mice with different combinations of mutant alleles were monitored over a time span of 2 years. The mice did not show any behavioral/neurological changes during the first 18 months of age. However, after aging (> 18 months of age), both the Rheb1 +/- and Rheb1 Δ /- hybrid males developed rare stress-induced seizures, whereas Rheb1 +/- and Rheb1 Δ /- females and Rheb1 Δ/+ and Rheb1 Δ/Δ mice of both genders did not show any abnormality. Our findings suggest that chronic intervention with mTORC1 signaling in the aged brain might be associated with major adverse events.
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Shehata HS, AbdelGhaffar HM, Nasreldin M, Elmazny A, Abdelalim A, Sabbah A, Shalaby NM. Clinical patterns and outcomes of status epilepticus in patients with tuberous sclerosis complex. Ther Clin Risk Manag 2017; 13:779-785. [PMID: 28721058 PMCID: PMC5501639 DOI: 10.2147/tcrm.s138576] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
INTRODUCTION Refractory epilepsy is a common clinical manifestation in patients with tuberous sclerosis complex (TSC), which can be complicated by many life-threatening conditions, such as status epilepticus (SE). However, very few reports mention the patterns and semiology of SE in those patients. OBJECTIVE To study the clinical characteristics and outcomes of SE in TSC patients. MATERIALS AND METHODS This observational, prospective study was carried out on 36 Egyptian children with definite TSC. Clinical history, general and neurological examination and psychometric evaluation by standard questionnaires were used to explore characteristics of epileptic manifestations and clinical patterns of SE. All included patients were required to have long-term video electroencephalograms (EEGs) and brain MRI performed. RESULTS A total of 32 attacks of SE were recorded in 21 patients (58.3%) in our cohort during a follow-up period of 2.8±1.1 years; of those patients, 15 had convulsive status, 7 had non-convulsive SE, 6 had refractory/super-refractory SE and 14 patients had a history of infantile spasms (epileptic spasms). The duration of status ranged from 40 to 150 min (mean ± standard deviation: 90±15). Fourteen patients with SE had severe mental retardation, 9 had autistic spectrum disorder and 22 had severe epileptogenic EEG findings. Patients with SE had higher tuber numbers (mean: 9.6), 5 patients had subependymal giant cell astrocytomas and 2 patients had their SE after receiving everolimus. CONCLUSIONS The incidence of SE in our patient sample is high (>50%); severe mental retardation, autistic features, history of infantile spasm (epileptic spasms) and high tuber burden are risk factors for developing SE.
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Zamora C, Huisman TA, Izbudak I. Supratentorial Tumors in Pediatric Patients. Neuroimaging Clin N Am 2017; 27:39-67. [DOI: 10.1016/j.nic.2016.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
Epilepsy is one of the most common neurologic disorders, affecting about 50 million people worldwide. The disease is characterized by recurrent seizures, which are due to aberrant neuronal networks resulting in synchronous discharges. The term epilepsy encompasses a large spectrum of syndromes and diseases with different etiopathogenesis. The recent development of imaging and epilepsy surgery techniques is now enabling the identification of structural abnormalities that are part of the epileptic network, and the removal of these lesions may result in control of seizures. Access of this clinically well-characterized neurosurgical material has provided neuropathologists with the opportunity to study a variety of structural brain abnormalities associated with epilepsy, by combining traditional routine histopathologic methods with molecular genetics and functional analysis of the resected tissue. This approach has contributed greatly to a better diagnosis and classification of these structural lesions, and has provided important new insights into their pathogenesis and epileptogenesis. The present chapter provides a detailed description of the large spectrum of histopathologic findings encountered in epilepsy surgery patients, addressing in particular the nonneoplastic pathologies, including hippocampal sclerosis, malformations of cortical development, Sturge-Weber syndrome, and Rasmussen encephalitis, and reviews current knowledge regarding the underlying molecular pathomechanisms and cellular mechanisms mediating hyperexcitability.
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Affiliation(s)
- Eleonora Aronica
- Department of Neuropathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland, the Netherlands.
| | - Angelika Mühlebner
- Department of Neuropathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
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Robens BK, Grote A, Pitsch J, Schoch S, Cardoso C, Becker AJ. Minute amounts of hamartin wildtype rescue the emergence of tuber-like lesions in conditional Tsc1 ablated mice. Neurobiol Dis 2016; 95:134-44. [PMID: 27425891 DOI: 10.1016/j.nbd.2016.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 07/05/2016] [Accepted: 07/13/2016] [Indexed: 11/29/2022] Open
Abstract
Tuberous sclerosis (TSC) is a phacomatosis associated with highly differentiated malformations including tubers in the brain. Those are composed of large dysplastic neurons and 'giant cells'. Cortical tubers are frequent causes of chronic seizures and resemble neuropathologically focal cortical dysplasias (FCD) type IIb. Patients with FCDIIb, however, lack additional stigmata of TSC. Mutations and allelic variants of the TSC1 gene have been observed in patients with tubers as well as FCDIIb. Those include hamartin(R692X) and hamartin(R786X), stop mutants frequent in TSC patients and hamartin(H732Y) frequent in FCDIIb. Expression of these variants in cell culture led to aberrant distribution of corresponding proteins. We here scrutinized morphological and structural effects of these TSC1 variants by intraventricular in utero electroporation (IUE), genetically mimicking the discrete focal character and a somatic postzygotic mosaicism of the lesion, focusing on the gene dosage required for tuber-like lesions to emerge in Tsc1(flox/flox) mice. Expression of only hamartin(R692X) as well as hamartin(R786X) led to a 2-fold enlargement of neurons with high pS6 immunoreactivity, stressing their in vivo pathogenic potential. Co-electroporation of the different aberrant alleles and varying amounts of wildtype TSC1 surprisingly revealed already minimal amounts of functional hamartin to be sufficient for phenotype rescue. This result strongly calls for further studies to unravel new mechanisms for substantial silencing of the second allele in cortical tubers, as proposed by Knudson's '2-hit hypothesis'. The rescuing effects may provide a promising basis for gene therapies aiming at reconstituting hamartin expression in tubers.
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Affiliation(s)
- Barbara K Robens
- Section for Translational Epilepsy Research, Dept. of Neuropathology, Germany
| | | | - Julika Pitsch
- Section for Translational Epilepsy Research, Dept. of Neuropathology, Germany
| | - Susanne Schoch
- Section for Translational Epilepsy Research, Dept. of Neuropathology, Germany
| | - Carlos Cardoso
- INSERM, Institut de Neurobiologie de la Méditerranée, Marseille, France; Aix-Marseille University, UMR 901 Marseille, France
| | - Albert J Becker
- Section for Translational Epilepsy Research, Dept. of Neuropathology, Germany.
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van Scheppingen J, Iyer AM, Prabowo AS, Mühlebner A, Anink JJ, Scholl T, Feucht M, Jansen FE, Spliet WG, Krsek P, Zamecnik J, Buccoliero AM, Giordano F, Genitori L, Kotulska K, Jozwiak S, Jaworski J, Liszewska E, van Vliet EA, Aronica E. Expression of microRNAs miR21, miR146a, and miR155 in tuberous sclerosis complex cortical tubers and their regulation in human astrocytes and SEGA-derived cell cultures. Glia 2016; 64:1066-82. [PMID: 27014996 DOI: 10.1002/glia.22983] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/29/2016] [Accepted: 03/02/2016] [Indexed: 12/23/2022]
Abstract
Tuberous sclerosis complex (TSC) is a genetic disease presenting with multiple neurological symptoms including epilepsy, mental retardation, and autism. Abnormal activation of various inflammatory pathways has been observed in astrocytes in brain lesions associated with TSC. Increasing evidence supports the involvement of microRNAs in the regulation of astrocyte-mediated inflammatory response. To study the role of inflammation-related microRNAs in TSC, we employed real-time PCR and in situ hybridization to characterize the expression of miR21, miR146a, and miR155 in TSC lesions (cortical tubers and subependymal giant cell astrocytomas, SEGAs). We observed an increased expression of miR21, miR146a, and miR155 in TSC tubers compared with control and perituberal brain tissue. Expression was localized in dysmorphic neurons, giant cells, and reactive astrocytes and positively correlated with IL-1β expression. In addition, cultured human astrocytes and SEGA-derived cell cultures were used to study the regulation of the expression of these miRNAs in response to the proinflammatory cytokine IL-1β and to evaluate the effects of overexpression or knockdown of miR21, miR146a, and miR155 on inflammatory signaling. IL-1β stimulation of cultured glial cells strongly induced intracellular miR21, miR146a, and miR155 expression, as well as miR146a extracellular release. IL-1β signaling was differentially modulated by overexpression of miR155 or miR146a, which resulted in pro- or anti-inflammatory effects, respectively. This study provides supportive evidence that inflammation-related microRNAs play a role in TSC. In particular, miR146a and miR155 appear to be key players in the regulation of astrocyte-mediated inflammatory response, with miR146a as most interesting anti-inflammatory therapeutic candidate.
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Affiliation(s)
- J van Scheppingen
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - A M Iyer
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - A S Prabowo
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - A Mühlebner
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - J J Anink
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - T Scholl
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - M Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - F E Jansen
- Department of Pediatric Neurology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - W G Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - P Krsek
- Department of Pediatric Neurology, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - J Zamecnik
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - A M Buccoliero
- Pathology Unit, Anna Meyer Children's Hospital, Florence, Italy
| | - F Giordano
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - L Genitori
- Department of Neurosurgery, Anna Meyer Children's Hospital, Florence, Italy
| | - K Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - S Jozwiak
- Department of Child Neurology, Medical University of Warsaw, Warsaw, Poland
| | - J Jaworski
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - E Liszewska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - E A van Vliet
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - E Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), the Netherlands
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45
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Tee AR, Sampson JR, Pal DK, Bateman JM. The role of mTOR signalling in neurogenesis, insights from tuberous sclerosis complex. Semin Cell Dev Biol 2016; 52:12-20. [PMID: 26849906 DOI: 10.1016/j.semcdb.2016.01.040] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/05/2016] [Accepted: 01/25/2016] [Indexed: 11/30/2022]
Abstract
Understanding the development and function of the nervous system is one of the foremost aims of current biomedical research. The nervous system is generated during a relatively short period of intense neurogenesis that is orchestrated by a number of key molecular signalling pathways. Even subtle defects in the activity of these molecules can have serious repercussions resulting in neurological, neurodevelopmental and neurocognitive problems including epilepsy, intellectual disability and autism. Tuberous sclerosis complex (TSC) is a monogenic disease characterised by these problems and by the formation of benign tumours in multiple organs, including the brain. TSC is caused by mutations in the TSC1 or TSC2 gene leading to activation of the mechanistic target of rapamycin (mTOR) signalling pathway. A desire to understand the neurological manifestations of TSC has stimulated research into the role of the mTOR pathway in neurogenesis. In this review we describe TSC neurobiology and how the use of animal model systems has provided insights into the roles of mTOR signalling in neuronal differentiation and migration. Recent progress in this field has identified novel mTOR pathway components regulating neuronal differentiation. The roles of mTOR signalling and aberrant neurogenesis in epilepsy are also discussed. Continuing efforts to understand mTOR neurobiology will help to identify new therapeutic targets for TSC and other neurological diseases.
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Affiliation(s)
- Andrew R Tee
- Institute of Cancer & Genetics, Cardiff University School of Medicine, Institute of Medical Genetics Building, Heath Park, Cardiff CF14 4XN UK
| | - Julian R Sampson
- Institute of Cancer & Genetics, Cardiff University School of Medicine, Institute of Medical Genetics Building, Heath Park, Cardiff CF14 4XN UK
| | - Deb K Pal
- Department of Basic & Clinical Neurosciences, Institute of Psychiatry, Psychology & Neuroscience, King's College, London SE5 8RX UK
| | - Joseph M Bateman
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London SE1 1UL UK.
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46
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Tian Q, Smart JL, Clement JH, Wang Y, Derkatch A, Schubert H, Danilchik MV, Marks DL, Fedorov LM. RHEB1 expression in embryonic and postnatal mouse. Histochem Cell Biol 2015; 145:561-72. [PMID: 26708151 DOI: 10.1007/s00418-015-1394-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2015] [Indexed: 12/16/2022]
Abstract
Ras homolog enriched in brain (RHEB1) is a member within the superfamily of GTP-binding proteins encoded by the RAS oncogenes. RHEB1 is located at the crossroad of several important pathways including the insulin-signaling pathways and thus plays an important role in different physiological processes. To understand better the physiological relevance of RHEB1 protein, the expression pattern of RHEB1 was analyzed in both embryonic (at E3.5-E16.5) and adult (1-month old) mice. RHEB1 immunostaining and X-gal staining were used for wild-type and Rheb1 gene trap mutant mice, respectively. These independent methods revealed similar RHEB1 expression patterns during both embryonic and postnatal developments. Ubiquitous uniform RHEB1/β-gal and/or RHEB1 expression was seen in preimplantation embryos at E3.5 and postimplantation embryos up to E12.5. Between stages E13.5 and E16.5, RHEB1 expression levels became complex: In particular, strong expression was identified in neural tissues, including the neuroepithelial layer of the mesencephalon, telencephalon, and neural tube of CNS and dorsal root ganglia. In addition, strong expression was seen in certain peripheral tissues including heart, intestine, muscle, and urinary bladder. Postnatal mice have broad spatial RHEB1 expression in different regions of the cerebral cortex, subcortical regions (including hippocampus), olfactory bulb, medulla oblongata, and cerebellum (particularly in Purkinje cells). Significant RHEB1 expression was also viewed in internal organs including the heart, intestine, urinary bladder, and muscle. Moreover, adult animals have complex tissue- and organ-specific RHEB1 expression patterns with different intensities observed throughout postnatal development. Its expression level is in general comparable in CNS and other organs of mouse. Thus, the expression pattern of RHEB1 suggests that it likely plays a ubiquitous role in the development of the early embryo with more tissue-specific roles in later development.
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Affiliation(s)
- Qi Tian
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | | | - Joachim H Clement
- Department of Hematology and Oncology, Jena University Hospital, 07747, Jena, Germany
| | - Yingming Wang
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Alex Derkatch
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | | | - Michael V Danilchik
- Department of Integrative Biosciences, Oregon Health and Science University, Portland, OR, USA
| | - Daniel L Marks
- Department of Pediatrics, Oregon Health and Science University, Portland, OR, USA
| | - Lev M Fedorov
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
- Friedrich-Schiller-University, 07740, Jena, Germany.
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47
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Sundberg M, Sahin M. Cerebellar Development and Autism Spectrum Disorder in Tuberous Sclerosis Complex. J Child Neurol 2015; 30:1954-62. [PMID: 26303409 PMCID: PMC4644486 DOI: 10.1177/0883073815600870] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 07/15/2015] [Indexed: 01/08/2023]
Abstract
Approximately 50% of patients with the genetic disease tuberous sclerosis complex present with autism spectrum disorder. Although a number of studies have investigated the link between autism and tuberous sclerosis complex, the etiology of autism spectrum disorder in these patients remains unclear. Abnormal cerebellar function during critical phases of development could disrupt functional processes in the brain, leading to development of autistic features. Accordingly, the authors review the potential role of cerebellar dysfunction in the pathogenesis of autism spectrum disorder in tuberous sclerosis complex. The authors also introduce conditional knockout mouse models of Tsc1 and Tsc2 that link cerebellar circuitry to the development of autistic-like features. Taken together, these preclinical and clinical investigations indicate the cerebellum has a profound regulatory role during development of social communication and repetitive behaviors.
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Affiliation(s)
- Maria Sundberg
- The F.M. Kirby Neurobiology Center, Department of Neurology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
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Complex Neurological Phenotype in Mutant Mice Lacking Tsc2 in Excitatory Neurons of the Developing Forebrain(123). eNeuro 2015; 2:eN-NWR-0046-15. [PMID: 26693177 PMCID: PMC4676199 DOI: 10.1523/eneuro.0046-15.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 09/09/2015] [Accepted: 09/14/2015] [Indexed: 11/25/2022] Open
Abstract
Mutations in the TSC1 and TSC2 genes cause tuberous sclerosis complex (TSC), a genetic disease often associated with epilepsy, intellectual disability, and autism, and characterized by the presence of anatomical malformations in the brain as well as tumors in other organs. The TSC1 and TSC2 proteins form a complex that inhibits mammalian target of rapamycin complex 1 (mTORC1) signaling. Previous animal studies demonstrated that Tsc1 or Tsc2 loss of function in the developing brain affects the intrinsic development of neural progenitor cells, neurons, or glia. However, the interplay between different cellular elements during brain development was not previously investigated. In this study, we generated a novel mutant mouse line (NEX-Tsc2) in which the Tsc2 gene is deleted specifically in postmitotic excitatory neurons of the developing forebrain. Homozygous mutant mice failed to thrive and died prematurely, whereas heterozygous mice appeared normal. Mutant mice exhibited distinct neuroanatomical abnormalities, including malpositioning of selected neuronal populations, neuronal hypertrophy, and cortical astrogliosis. Intrinsic neuronal defects correlated with increased mTORC1 signaling, whereas astrogliosis did not result from altered intrinsic signaling, since these cells were not directly affected by the gene knockout strategy. All neuronal and non-neuronal abnormalities were suppressed by continuous postnatal treatment with the mTORC1 inhibitor RAD001. The data suggest that the loss of Tsc2 and mTORC1 signaling activation in excitatory neurons not only disrupts their intrinsic development, but also disrupts the development of cortical astrocytes, likely through the mTORC1-dependent expression of abnormal signaling proteins. This work thus provides new insights into cell-autonomous and non-cell-autonomous functions of Tsc2 in brain development.
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Malik AR, Liszewska E, Skalecka A, Urbanska M, Iyer AM, Swiech LJ, Perycz M, Parobczak K, Pietruszka P, Zarebska MM, Macias M, Kotulska K, Borkowska J, Grajkowska W, Tyburczy ME, Jozwiak S, Kwiatkowski DJ, Aronica E, Jaworski J. Tuberous sclerosis complex neuropathology requires glutamate-cysteine ligase. Acta Neuropathol Commun 2015. [PMID: 26220190 PMCID: PMC4518593 DOI: 10.1186/s40478-015-0225-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Tuberous sclerosis complex (TSC) is a genetic disease resulting from mutation in TSC1 or TSC2 and subsequent hyperactivation of mammalian Target of Rapamycin (mTOR). Common TSC features include brain lesions, such as cortical tubers and subependymal giant cell astrocytomas (SEGAs). However, the current treatment with mTOR inhibitors has critical limitations. We aimed to identify new targets for TSC pharmacotherapy. RESULTS The results of our shRNA screen point to glutamate-cysteine ligase catalytic subunit (GCLC), a key enzyme in glutathione synthesis, as a contributor to TSC-related phenotype. GCLC inhibition increased cellular stress and reduced mTOR hyperactivity in TSC2-depleted neurons and SEGA-derived cells. Moreover, patients' brain tubers showed elevated GCLC and stress markers expression. Finally, GCLC inhibition led to growth arrest and death of SEGA-derived cells. CONCLUSIONS We describe GCLC as a part of redox adaptation in TSC, needed for overgrowth and survival of mutant cells, and provide a potential novel target for SEGA treatment.
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Tuberous Sclerosis Complex: State-of-the-Art Review with a Focus on Pulmonary Involvement. Lung 2015; 193:619-27. [DOI: 10.1007/s00408-015-9750-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 06/15/2015] [Indexed: 12/19/2022]
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