1
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Miyoshi G, Ueta Y, Yagasaki Y, Kishi Y, Fishell G, Machold RP, Miyata M. Developmental trajectories of GABAergic cortical interneurons are sequentially modulated by dynamic FoxG1 expression levels. Proc Natl Acad Sci U S A 2024; 121:e2317783121. [PMID: 38588430 PMCID: PMC11032493 DOI: 10.1073/pnas.2317783121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 03/04/2024] [Indexed: 04/10/2024] Open
Abstract
GABAergic inhibitory interneurons, originating from the embryonic ventral forebrain territories, traverse a convoluted migratory path to reach the neocortex. These interneuron precursors undergo sequential phases of tangential and radial migration before settling into specific laminae during differentiation. Here, we show that the developmental trajectory of FoxG1 expression is dynamically controlled in these interneuron precursors at critical junctures of migration. By utilizing mouse genetic strategies, we elucidate the pivotal role of precise changes in FoxG1 expression levels during interneuron specification and migration. Our findings underscore the gene dosage-dependent function of FoxG1, aligning with clinical observations of FOXG1 haploinsufficiency and duplication in syndromic forms of autism spectrum disorders. In conclusion, our results reveal the finely tuned developmental clock governing cortical interneuron development, driven by temporal dynamics and the dose-dependent actions of FoxG1.
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Affiliation(s)
- Goichi Miyoshi
- Department of Developmental Genetics and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi city, Gunma371-8511, Japan
- Department of Neurophysiology, Tokyo Women’s Medical University, Shinjuku, Tokyo162-8666, Japan
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY10016
| | - Yoshifumi Ueta
- Department of Neurophysiology, Tokyo Women’s Medical University, Shinjuku, Tokyo162-8666, Japan
| | - Yuki Yagasaki
- Department of Neurophysiology, Tokyo Women’s Medical University, Shinjuku, Tokyo162-8666, Japan
| | - Yusuke Kishi
- Laboratory of Molecular Neurobiology, Institute for Quantitative Biosciences, University of Tokyo, Bunkyo, Tokyo113-0032, Japan
- Laboratory of Molecular Biology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo, Tokyo113-0033, Japan
| | - Gord Fishell
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY10016
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA02115
- Stanley Center at the Broad Institute, Cambridge, MA02142
| | - Robert P. Machold
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY10016
| | - Mariko Miyata
- Department of Neurophysiology, Tokyo Women’s Medical University, Shinjuku, Tokyo162-8666, Japan
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2
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Dhamne SC, Modi ME, Gray A, Bonazzi S, Craig L, Bainbridge E, Lalani L, Super CE, Schaeffer S, Capre K, Lubicka D, Liang G, Burdette D, McTighe SM, Gurnani S, Vermudez SAD, Curtis D, Wilson CJ, Hameed MQ, D'Amore A, Rotenberg A, Sahin M. Seizure reduction in TSC2-mutant mouse model by an mTOR catalytic inhibitor. Ann Clin Transl Neurol 2023; 10:1790-1801. [PMID: 37545094 PMCID: PMC10578885 DOI: 10.1002/acn3.51868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 07/14/2023] [Accepted: 07/23/2023] [Indexed: 08/08/2023] Open
Abstract
OBJECTIVE Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder caused by autosomal-dominant pathogenic variants in either the TSC1 or TSC2 gene, and it is characterized by hamartomas in multiple organs, such as skin, kidney, lung, and brain. These changes can result in epilepsy, learning disabilities, and behavioral complications, among others. The mechanistic link between TSC and the mechanistic target of the rapamycin (mTOR) pathway is well established, thus mTOR inhibitors can potentially be used to treat the clinical manifestations of the disorder, including epilepsy. METHODS In this study, we tested the efficacy of a novel mTOR catalytic inhibitor (here named Tool Compound 1 or TC1) previously reported to be more brain-penetrant compared with other mTOR inhibitors. Using a well-characterized hypomorphic Tsc2 mouse model, which displays a translationally relevant seizure phenotype, we tested the efficacy of TC1. RESULTS Our results show that chronic treatment with this novel mTOR catalytic inhibitor (TC1), which affects both the mTORC1 and mTORC2 signaling complexes, reduces seizure burden, and extends the survival of Tsc2 hypomorphic mice, restoring species typical weight gain over development. INTERPRETATION Novel mTOR catalytic inhibitor TC1 exhibits a promising therapeutic option in the treatment of TSC.
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Affiliation(s)
- Sameer C. Dhamne
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Meera E. Modi
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Audrey Gray
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Simone Bonazzi
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Lucas Craig
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Elizabeth Bainbridge
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Lahin Lalani
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Chloe E. Super
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Samantha Schaeffer
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Ketthsy Capre
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Danuta Lubicka
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Guiqing Liang
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Doug Burdette
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | | | - Sarika Gurnani
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Sheryl Anne D. Vermudez
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Daniel Curtis
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | | | - Mustafa Q. Hameed
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Angelica D'Amore
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
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3
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Montero-Calle A, Coronel R, Garranzo-Asensio M, Solís-Fernández G, Rábano A, de Los Ríos V, Fernández-Aceñero MJ, Mendes ML, Martínez-Useros J, Megías D, Moreno-Casbas MT, Peláez-García A, Liste I, Barderas R. Proteomics analysis of prefrontal cortex of Alzheimer's disease patients revealed dysregulated proteins in the disease and novel proteins associated with amyloid-β pathology. Cell Mol Life Sci 2023; 80:141. [PMID: 37149819 PMCID: PMC11073180 DOI: 10.1007/s00018-023-04791-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 04/06/2023] [Accepted: 04/25/2023] [Indexed: 05/08/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is a progressive, chronic, and neurodegenerative disease, and the most common cause of dementia worldwide. Currently, the mechanisms underlying the disease are far from being elucidated. Thus, the study of proteins involved in its pathogenesis would allow getting further insights into the disease and identifying new markers for AD diagnosis. METHODS We aimed here to analyze protein dysregulation in AD brain by quantitative proteomics to identify novel proteins associated with the disease. 10-plex TMT (tandem mass tags)-based quantitative proteomics experiments were performed using frozen tissue samples from the left prefrontal cortex of AD patients and healthy individuals and vascular dementia (VD) and frontotemporal dementia (FTD) patients as controls (CT). LC-MS/MS analyses were performed using a Q Exactive mass spectrometer. RESULTS In total, 3281 proteins were identified and quantified using MaxQuant. Among them, after statistical analysis with Perseus (p value < 0.05), 16 and 155 proteins were defined as upregulated and downregulated, respectively, in AD compared to CT (Healthy, FTD and VD) with an expression ratio ≥ 1.5 (upregulated) or ≤ 0.67 (downregulated). After bioinformatics analysis, ten dysregulated proteins were selected as more prone to be associated with AD, and their dysregulation in the disease was verified by qPCR, WB, immunohistochemistry (IHC), immunofluorescence (IF), pull-down, and/or ELISA, using tissue and plasma samples of AD patients, patients with other dementias, and healthy individuals. CONCLUSIONS We identified and validated novel AD-associated proteins in brain tissue that should be of further interest for the study of the disease. Remarkably, PMP2 and SCRN3 were found to bind to amyloid-β (Aβ) fibers in vitro, and PMP2 to associate with Aβ plaques by IF, whereas HECTD1 and SLC12A5 were identified as new potential blood-based biomarkers of the disease.
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Affiliation(s)
- Ana Montero-Calle
- Functional Proteomics Unit, Chronic Disease Programme (UFIEC), Instituto de Salud Carlos III, Majadahonda, E-28220, Madrid, Spain
| | - Raquel Coronel
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - María Garranzo-Asensio
- Functional Proteomics Unit, Chronic Disease Programme (UFIEC), Instituto de Salud Carlos III, Majadahonda, E-28220, Madrid, Spain
| | - Guillermo Solís-Fernández
- Functional Proteomics Unit, Chronic Disease Programme (UFIEC), Instituto de Salud Carlos III, Majadahonda, E-28220, Madrid, Spain
- Molecular Imaging and Photonics Division, Chemistry Department, Faculty of Sciences, KU Leuven, Celestijnenlaan 200F, Heverlee, 3001, Louvain, Belgium
| | - Alberto Rábano
- Alzheimer Disease Research Unit, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, E-28031, Madrid, Spain
| | | | | | - Marta L Mendes
- Department of Infection and Immunity, Luxembourg Institute of Health, L-1445, Strassen, Luxembourg
| | - Javier Martínez-Useros
- Translational Oncology Division, OncoHealth Institute, Health Research Institute-University Hospital Fundación Jiménez Díaz-Universidad Autónoma de Madrid, E-28040, Madrid, Spain
- Area of Physiology, Department of Basic Health Sciences, Faculty of Health Sciences, Rey Juan Carlos University, E-28922, Madrid, Spain
| | - Diego Megías
- Advanced Optical Microscopy Unit, UCCTs, Instituto de Salud Carlos III (ISCIII), E-28220, Majadahonda, Madrid, Spain
| | | | - Alberto Peláez-García
- Molecular Pathology and Therapeutic Targets Group, La Paz University Hospital (IdiPAZ), E-28046, Madrid, Spain
| | - Isabel Liste
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Rodrigo Barderas
- Functional Proteomics Unit, Chronic Disease Programme (UFIEC), Instituto de Salud Carlos III, Majadahonda, E-28220, Madrid, Spain.
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4
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Fidalgo da Silva E, Abu Khatir B, Drouillard C, Hinch I, Davis GO, Sameem M, Patel R, Fong J, Lubanska D, Porter LA. Tuberin levels during cellular differentiation in brain development. Differentiation 2023; 130:43-50. [PMID: 36608575 DOI: 10.1016/j.diff.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/13/2022] [Accepted: 12/21/2022] [Indexed: 12/26/2022]
Abstract
Tuberin is a member of a large protein complex, Tuberous Sclerosis Complex (TSC), and acts as a sensor for nutrient status regulating protein synthesis and cell cycle progression. Mutations in the Tuberin gene, TSC2, permits the formation of tumors that can lead to developmental defects in many organ systems, including the central nervous system. Tuberin is expressed in the brain throughout development and levels of Tuberin have been found to decrease during neuronal differentiation in cell lines in vitro. Our current work investigates the levels of Tuberin at two stages of embryonic development in vivo, and we study the mRNA and protein levels during a time course using immortalized cell lines in vitro. Our results show that total Tuberin levels are tightly regulated through developmental stages in the embryonic brain. At a cell biology level, we show that Tuberin levels are higher when cells are cultured as neurospheres, and knockdown of Tuberin results in a reduction in the number of neurospheres. This functional data supports the hypothesis that Tuberin is an important regulator of stemness and the reduction of Tuberin levels might support functional differentiation in the central nervous system. Understanding how Tuberin expression is regulated throughout neural development is essential to fully comprehend the role of this protein in several developmental and neural pathologies.
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Affiliation(s)
- Elizabeth Fidalgo da Silva
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Bashaer Abu Khatir
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Christopher Drouillard
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Isabelle Hinch
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Gordon Omar Davis
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Mariam Sameem
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Rutu Patel
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Jackie Fong
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Dorota Lubanska
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Lisa A Porter
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada.
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5
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Yuskaitis CJ, Modasia JB, Schrötter S, Rossitto LA, Groff KJ, Morici C, Mithal DS, Chakrabarty RP, Chandel NS, Manning BD, Sahin M. DEPDC5-dependent mTORC1 signaling mechanisms are critical for the anti-seizure effects of acute fasting. Cell Rep 2022; 40:111278. [PMID: 36044864 PMCID: PMC9508617 DOI: 10.1016/j.celrep.2022.111278] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/11/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
Caloric restriction and acute fasting are known to reduce seizures but through unclear mechanisms. mTOR signaling has been suggested as a potential mechanism for seizure protection from fasting. We demonstrate that brain mTORC1 signaling is reduced after acute fasting of mice and that neuronal mTORC1 integrates GATOR1 complex-mediated amino acid and tuberous sclerosis complex (TSC)-mediated growth factor signaling. Neuronal mTORC1 is most sensitive to withdrawal of leucine, arginine, and glutamine, which are dependent on DEPDC5, a component of the GATOR1 complex. Metabolomic analysis reveals that Depdc5 neuronal-specific knockout mice are resistant to sensing significant fluctuations in brain amino acid levels after fasting. Depdc5 neuronal-specific knockout mice are resistant to the protective effects of fasting on seizures or seizure-induced death. These results establish that acute fasting reduces seizure susceptibility in a DEPDC5-dependent manner. Modulation of nutrients upstream of GATOR1 and mTORC1 could offer a rational therapeutic strategy for epilepsy treatment.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jinita B Modasia
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sandra Schrötter
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Leigh-Ana Rossitto
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Karenna J Groff
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christopher Morici
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Divakar S Mithal
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Section of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Ram P Chakrabarty
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Navdeep S Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Brendan D Manning
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Boston, MA, USA.
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6
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Terashima H, Minatohara K, Maruoka H, Okabe S. Imaging neural circuit pathology of autism spectrum disorders: autism-associated genes, animal models and the application of in vivo two-photon imaging. Microscopy (Oxf) 2022; 71:i81-i99. [DOI: 10.1093/jmicro/dfab039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/11/2021] [Accepted: 11/08/2021] [Indexed: 11/12/2022] Open
Abstract
Abstract
Recent advances in human genetics identified genetic variants involved in causing autism spectrum disorders (ASDs). Mouse models that mimic mutations found in patients with ASD exhibit behavioral phenotypes consistent with ASD symptoms. These mouse models suggest critical biological factors of ASD etiology. Another important implication of ASD genetics is the enrichment of ASD risk genes in molecules involved in developing synapses and regulating neural circuit function. Sophisticated in vivo imaging technologies applied to ASD mouse models identify common synaptic impairments in the neocortex, with genetic-mutation-specific defects in local neural circuits. In this article, we review synapse- and circuit-level phenotypes identified by in vivo two-photon imaging in multiple mouse models of ASD and discuss the contributions of altered synapse properties and neural circuit activity to ASD pathogenesis.
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Affiliation(s)
- Hiroshi Terashima
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Keiichiro Minatohara
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisato Maruoka
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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7
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Petrasek T, Vojtechova I, Klovrza O, Tuckova K, Vejmola C, Rak J, Sulakova A, Kaping D, Bernhardt N, de Vries PJ, Otahal J, Waltereit R. mTOR inhibitor improves autistic-like behaviors related to Tsc2 haploinsufficiency but not following developmental status epilepticus. J Neurodev Disord 2021; 13:14. [PMID: 33863288 PMCID: PMC8052752 DOI: 10.1186/s11689-021-09357-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/18/2021] [Indexed: 12/18/2022] Open
Abstract
Background Tuberous sclerosis complex (TSC), a multi-system genetic disorder often associated with autism spectrum disorder (ASD), is caused by mutations of TSC1 or TSC2, which lead to constitutive overactivation of mammalian target of rapamycin (mTOR). In several Tsc1+/- and Tsc2+/- animal models, cognitive and social behavior deficits were reversed by mTOR inhibitors. However, phase II studies have not shown amelioration of ASD and cognitive deficits in individuals with TSC during mTOR inhibitor therapy. We asked here if developmental epilepsy, common in the majority of individuals with TSC but absent in most animal models, could explain the discrepancy. Methods At postnatal day P12, developmental status epilepticus (DSE) was induced in male Tsc2+/- (Eker) and wild-type rats, establishing four experimental groups including controls. In adult animals (n = 36), the behavior was assessed in the paradigms of social interaction test, elevated plus-maze, light-dark test, Y-maze, and novel object recognition. The testing was carried out before medication (T1), during a 2-week treatment with the mTOR inhibitor everolimus (T2) and after an 8-week washing-out (T3). Electroencephalographic (EEG) activity was recorded in a separate set of animals (n = 18). Results Both Tsc2+/- mutation and DSE caused social behavior deficits and epileptiform EEG abnormalities (T1). Everolimus led to a persistent improvement of the social deficit induced by Tsc2+/-, while deficits related to DSE did not respond to everolimus (T2, T3). Conclusions These findings may contribute to an explanation why ASD symptoms in individuals with TSC, where comorbid early-onset epilepsy is common, were not reliably ameliorated by mTOR inhibitors in clinical studies. Supplementary Information The online version contains supplementary material available at 10.1186/s11689-021-09357-2.
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Affiliation(s)
- Tomas Petrasek
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic.
| | - Iveta Vojtechova
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic.,First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ondrej Klovrza
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic.,Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Klara Tuckova
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Cestmir Vejmola
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Jakub Rak
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Anna Sulakova
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Daniel Kaping
- National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Nadine Bernhardt
- Department of Psychiatry, University Hospital and Medical Faculty Carl Gustav Carus, Technical University of Dresden, Dresden, Germany
| | - Petrus J de Vries
- Division of Child & Adolescent Psychiatry, University of Cape Town, Cape Town, South Africa
| | - Jakub Otahal
- Department of Developmental Epileptology, Institute of Physiology CAS, Prague, Czech Republic
| | - Robert Waltereit
- Department of Child and Adolescent Psychiatry, University Hospital and Medical Faculty Carl Gustav Carus, Technical University of Dresden, Dresden, Germany. .,Department of Child and Adolescent Psychiatry, University Medical Center Göttingen, Von-Siebold-Str. 5, 37075, Göttingen, Germany.
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8
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Inhibition of mTOR signaling by genetic removal of p70 S6 kinase 1 increases anxiety-like behavior in mice. Transl Psychiatry 2021; 11:165. [PMID: 33723223 PMCID: PMC7960700 DOI: 10.1038/s41398-020-01187-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/31/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a ubiquitously expressed kinase that acts through two complexes, mTORC1 and mTORC2, to regulate protein homeostasis, as well as long lasting forms of synaptic and behavioral plasticity. Alteration of the mTOR pathway is classically involved in neurodegenerative disorders, and it has been linked to dysregulation of cognitive functions and affective states. However, information concerning the specific involvement of the p70 S6 kinase 1 (S6K1), a downstream target of the mTORC1 pathway, in learning and memory processes and in the regulation of affective states remains scant. To fill this gap, we exposed adult male mice lacking S6K1 to a battery of behavioral tests aimed at measuring their learning and memory capabilities by evaluating reference memory and flexibility with the Morris water maze, and associative memory using the contextual fear conditioning task. We also studied their anxiety-like and depression-like behaviors by, respectively, performing elevated plus maze, open field, light-dark emergence tests, and sucrose preference and forced swim tests. We found that deleting S6K1 leads to a robust anxious phenotype concomitant with associative learning deficits; these symptoms are associated with a reduction of adult neurogenesis and neuronal atrophy in the hippocampus. Collectively, these results provide grounds for the understanding of anxiety reports after treatments with mTOR inhibitors and will be critical for developing novel compounds targeting anxiety.
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9
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Modeling Neurodevelopmental Deficits in Tuberous Sclerosis Complex with Stem Cell Derived Neural Precursors and Neurons. ADVANCES IN NEUROBIOLOGY 2020. [PMID: 32578142 DOI: 10.1007/978-3-030-45493-7_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Tuberous sclerosis complex (TSC) is a rare genetic disorder that is caused by mutations in TSC1 or TSC2. TSC is a multi-organ disorder characterized by development of non-malignant cellular overgrowths, called hamartomas, in different organs of the body. TSC is also characterized as a neurodevelopmental disorder presenting with epilepsy and autism, and formation of cortical malformations ("tubers"), subependymal giant cell astrocytomas (SEGAs), and subependymal nodules (SENs) in the patient's brain. In this chapter, we are going to give an overview of neural stem cell and neuronal development in TSC. In addition, we will also describe previously developed animal models of TSC that display seizures, autistic-like behaviors, and neuronal cell abnormalities in vivo, and we will compare them to disease phenotypes detected with human stem cell derived neuronal cells in vitro. We will describe the effects of TSC-mutations in different neural cell subtypes, and discuss the mitochondrial function, autophagy, and synaptic development and functional deficits in the neurons. Finally, we will review utilization of these human TSC-patient derived neuronal models for drug screening to develop new treatment options for the neurological phenotypes seen in TSC patients.
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10
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Yuskaitis CJ, Rossitto LA, Gurnani S, Bainbridge E, Poduri A, Sahin M. Chronic mTORC1 inhibition rescues behavioral and biochemical deficits resulting from neuronal Depdc5 loss in mice. Hum Mol Genet 2020; 28:2952-2964. [PMID: 31174205 DOI: 10.1093/hmg/ddz123] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 01/05/2023] Open
Abstract
DEPDC5 is now recognized as one of the genes most often implicated in familial/inherited focal epilepsy and brain malformations. Individuals with pathogenic variants in DEPDC5 are at risk for epilepsy, associated neuropsychiatric comorbidities and sudden unexplained death in epilepsy. Depdc5flox/flox-Syn1Cre (Depdc5cc+) neuronal-specific Depdc5 knockout mice exhibit seizures and neuronal mTORC1 hyperactivation. It is not known if Depdc5cc+ mice have a hyperactivity/anxiety phenotype, die early from terminal seizures or whether mTOR inhibitors rescue DEPDC5-related seizures and associated comorbidities. Herein, we report that Depdc5cc+ mice were hyperactive in open-field testing but did not display anxiety-like behaviors on the elevated-plus maze. Unlike many other mTOR-related models, Depdc5cc+ mice had minimal epileptiform activity and rare seizures prior to seizure-induced death, as confirmed by video-EEG monitoring. Treatment with the mTORC1 inhibitor rapamycin starting after 3 weeks of age significantly prolonged the survival of Depdc5cc+ mice and partially rescued the behavioral hyperactivity. Rapamycin decreased the enlarged brain size of Depdc5cc+ mice with corresponding decrease in neuronal soma size. Loss of Depdc5 led to a decrease in the other GATOR1 protein levels (NPRL2 and NPRL3). Rapamycin failed to rescue GATOR1 protein levels but rather rescued downstream mTORC1 hyperactivity as measured by phosphorylation of S6. Collectively, our data provide the first evidence of behavioral alterations in mice with Depdc5 loss and support mTOR inhibition as a rational therapeutic strategy for DEPDC5-related epilepsy in humans.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Leigh-Ana Rossitto
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Sarika Gurnani
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Elizabeth Bainbridge
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
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11
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Iffland PH, Carson V, Bordey A, Crino PB. GATORopathies: The role of amino acid regulatory gene mutations in epilepsy and cortical malformations. Epilepsia 2019; 60:2163-2173. [PMID: 31625153 PMCID: PMC7155771 DOI: 10.1111/epi.16370] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin (mTOR) pathway has been implicated in a growing number of malformations of cortical development (MCD) associated with intractable epilepsy. Mutations in single genes encoding mTOR pathway regulatory proteins have been linked to MCD such as focal cortical dysplasia (FCD) types IIa and IIb, hemimegalencephaly (HME), and megalencephaly. Recent studies have demonstrated that the GATOR1 protein complex, comprised of DEPDC5, NPRL3, and NPRL2, plays a pivotal role in regulating mTOR signaling in response to cellular amino acid levels and that mutations in DEPDC5, NPRL3, or NPRL2 are linked to FCD, HME, and seizures. Histopathological analysis of FCD and HME tissue specimens resected from individuals harboring DEPDC5, NPRL3, or NPRL2 gene mutations reveals hyperactivation of mTOR pathway signaling. Family pedigrees carrying mutations in either DEPDC5 or NPRL3 share clinical phenotypes of epilepsy and MCD, as well as intellectual and neuropsychiatric disabilities. Interestingly, some individuals with seizures associated with DEPDC5, NPRL3, or NPRL2 variants exhibit normal brain imaging suggesting either occult MCD or a role for these genes in non-lesional neocortical epilepsy. Mouse models resulting from knockdown or knockout of either Depdc5 or Nprl3 exhibit altered cortical lamination, neuronal dysmorphogenesis, and enhanced neuronal excitability as reported in models resulting from direct mTOR activation through expression of its canonical activator RHEB. The role of the GATOR1 proteins in regulating mTOR signaling suggest plausible options for mTOR inhibition in the treatment of epilepsy associated with mutations in DEPDC5, NPRL3, or NPRL2.
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Affiliation(s)
- Philip H. Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vincent Carson
- The Clinic for Special Children, Strasburg, Pennsylvania
| | - Angelique Bordey
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Peter B. Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
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12
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Gewin LS, Summers ME, Harral JW, Gaskill CF, Khodo SN, Neelisetty S, Sullivan TM, Hopp K, Reese JJ, Klemm DJ, Kon V, Ess KC, Shi W, Majka SM. Inactivation of Tsc2 in Abcg2 lineage-derived cells drives the appearance of polycystic lesions and fibrosis in the adult kidney. Am J Physiol Renal Physiol 2019; 317:F1201-F1210. [PMID: 31461347 PMCID: PMC6879939 DOI: 10.1152/ajprenal.00629.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 08/07/2019] [Accepted: 08/22/2019] [Indexed: 02/08/2023] Open
Abstract
Tuberous sclerosis complex 2 (TSC2), or tuberin, is a pivotal regulator of the mechanistic target of rapamycin signaling pathway that controls cell survival, proliferation, growth, and migration. Loss of Tsc2 function manifests in organ-specific consequences, the mechanisms of which remain incompletely understood. Recent single cell analysis of the kidney has identified ATP-binding cassette G2 (Abcg2) expression in renal proximal tubules of adult mice as well as a in a novel cell population. The impact in adult kidney of Tsc2 knockdown in the Abcg2-expressing lineage has not been evaluated. We engineered an inducible system in which expression of truncated Tsc2, lacking exons 36-37 with an intact 3' region and polycystin 1, is driven by Abcg2. Here, we demonstrate that selective expression of Tsc2fl36-37 in the Abcg2pos lineage drives recombination in proximal tubule epithelial and rare perivascular mesenchymal cells, which results in progressive proximal tubule injury, impaired kidney function, formation of cystic lesions, and fibrosis in adult mice. These data illustrate the critical importance of Tsc2 function in the Abcg2-expressing proximal tubule epithelium and mesenchyme during the development of cystic lesions and remodeling of kidney parenchyma.
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Affiliation(s)
- Leslie S Gewin
- Division of Nephrology and Hypertension or Allergy, Department of Medicine, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
- Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Megan E Summers
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
| | - Julie W Harral
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
| | - Christa F Gaskill
- Division of Nephrology and Hypertension or Allergy, Department of Medicine, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee
| | - Stellor Nlandu Khodo
- Division of Nephrology and Hypertension or Allergy, Department of Medicine, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee
| | - Surekha Neelisetty
- Division of Nephrology and Hypertension or Allergy, Department of Medicine, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee
| | - Timothy M Sullivan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Katharina Hopp
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Aurora, Colorado
| | - J Jeffrey Reese
- Division of Nephrology or Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dwight J Klemm
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Valentina Kon
- Division of Nephrology or Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Kevin C Ess
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Wei Shi
- Children's Hospital of Los Angeles, Developmental Biology and Regenerative Medicine Program at the Saban Research Institute, Los Angeles, California
| | - Susan M Majka
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
- Gates Center for Regenerative Medicine and Stem Cell Biology, University of Colorado, Aurora, Colorado
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13
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Biallelic Mutations in TSC2 Lead to Abnormalities Associated with Cortical Tubers in Human iPSC-Derived Neurons. J Neurosci 2019; 39:9294-9305. [PMID: 31591157 DOI: 10.1523/jneurosci.0642-19.2019] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/02/2019] [Accepted: 08/30/2019] [Indexed: 12/18/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder caused by mutations in TSC1 or TSC2 Patients frequently have epilepsy, autism spectrum disorder, and/or intellectual disability, as well as other systemic manifestations. In this study, we differentiated human induced pluripotent stem cells (iPSCs) from a female patient with TSC with one or two mutations in TSC2 into neurons using induced expression of NGN2 to examine neuronal dysregulation associated with the neurological symptoms in TSC. Using this method, neuronal differentiation was comparable between the three genotypes of iPSCs. We observed that TSC2 +/- neurons show mTOR complex 1 (mTORC1) hyperactivation and associated increased cell body size and process outgrowth, as well as exacerbation of the abnormalities by loss of the second allele of TSC2 in TSC2 -/- neurons. Interestingly, iPSC-derived neurons with either a single or biallelic mutation in TSC2 demonstrated hypersynchrony and downregulation of FMRP targets. However, only neurons with biallelic mutations of TSC2 demonstrated hyperactivity and transcriptional dysregulation observed in cortical tubers. These data demonstrate that loss of one allele of TSC2 is sufficient to cause some morphological and physiological changes in human neurons but that biallelic mutations in TSC2 are necessary to induce gene expression dysregulation present in cortical tubers. Finally, we found that treatment of iPSC-derived neurons with rapamycin reduced neuronal activity and partially reversed gene expression abnormalities, demonstrating that mTOR dysregulation contributes to both phenotypes. Therefore, biallelic mutations in TSC2 and associated molecular dysfunction, including mTOR hyperactivation, may play a role in the development of cortical tubers.SIGNIFICANCE STATEMENT In this study, we examined neurons derived from induced pluripotent stem cells with two, one, or no functional TSC2 (tuberous sclerosis complex 2) alleles and found that loss of one or both alleles of TSC2 results in mTORC1 hyperactivation and specific neuronal abnormalities. However, only biallelic mutations in TSC2 resulted in elevated neuronal activity and upregulation of cell adhesion genes that is also observed in cortical tubers. These data suggest that loss of heterozygosity of TSC1 or TSC2 may play an important role in the development of cortical tubers, and potentially epilepsy, in patients with TSC.
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14
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Yamada D, Kawabe K, Tosa I, Tsukamoto S, Nakazato R, Kou M, Fujikawa K, Nakamura S, Ono M, Oohashi T, Kaneko M, Go S, Hinoi E, Yoneda Y, Takarada T. Inhibition of the glutamine transporter SNAT1 confers neuroprotection in mice by modulating the mTOR-autophagy system. Commun Biol 2019; 2:346. [PMID: 31552299 PMCID: PMC6751179 DOI: 10.1038/s42003-019-0582-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 08/19/2019] [Indexed: 01/31/2023] Open
Abstract
The pathophysiological role of mammalian target of rapamycin complex 1 (mTORC1) in neurodegenerative diseases is established, but possible therapeutic targets responsible for its activation in neurons must be explored. Here we identified solute carrier family 38a member 1 (SNAT1, Slc38a1) as a positive regulator of mTORC1 in neurons. Slc38a1flox/flox and Synapsin I-Cre mice were crossed to generate mutant mice in which Slc38a1 was selectively deleted in neurons. Measurement of 2,3,5-triphenyltetrazolium chloride (TTC) or the MAP2-negative area in a mouse model of middle cerebral artery occlusion (MCAO) revealed that Slc38a1 deficiency decreased infarct size. We found a transient increase in the phosphorylation of p70S6k1 (pp70S6k1) and a suppressive effect of rapamycin on infarct size in MCAO mice. Autophagy inhibitors completely mitigated the suppressive effect of SNAT1 deficiency on neuronal cell death under in vitro stroke culture conditions. These results demonstrate that SNAT1 promoted ischemic brain damage via mTOR-autophagy system.
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Affiliation(s)
- Daisuke Yamada
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Kenji Kawabe
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Ikue Tosa
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Shunpei Tsukamoto
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Ryota Nakazato
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Miki Kou
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Koichi Fujikawa
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Saki Nakamura
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Mitsuaki Ono
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Toshitaka Oohashi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
| | - Mari Kaneko
- Laboratory for Animal Resource Development Unit and Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami, Chuou-ku, Kobe, Hyogo 650-0047 Japan
| | - Shioi Go
- Laboratory for Animal Resource Development Unit and Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami, Chuou-ku, Kobe, Hyogo 650-0047 Japan
| | - Eiichi Hinoi
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Yukio Yoneda
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa 920-1192 Japan
| | - Takeshi Takarada
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558 Japan
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15
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Du H, Dreier JR, Zarei M, Wu CL, Bronson RW, Kwiatkowski DJ. A novel mouse model of hemangiopericytoma due to loss of Tsc2. Hum Mol Genet 2019; 27:4169-4175. [PMID: 30124871 DOI: 10.1093/hmg/ddy289] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/06/2018] [Indexed: 01/01/2023] Open
Abstract
Hemangiopericytoma (HPC) is a rare vascular tumor, which is thought to originate from pericytes. However, no direct evidence for the cell of origin has been found, and the mechanism of HPC tumorigenesis is poorly understood. Here we report that loss of the tumor suppressor gene Tsc2 in pericytes using a FoxD1 promoter driven cre allele (Foxd1tm1(GFP/cre) Amc, FoxD1GC) leads to the formation of HPC in multiple sites. Tsc2ffFoxD1GC mice had stunted growth with seizures and tail and hind limb tremor with a median survival of 110 days. They also showed recombination in brain, spinal cord, tongue, liver, intestine and skeletal muscle. Distinctive perivascular tumors consisting of cells with oval nuclei and scant cytoplasm were identified in multiple sites in all Tsc2ffFoxD1GC mice. Immunohistochemistry staining showed a high expression of phospho-S6-S240/244, a hallmark of activated mTORC1, as well as pericyte markers NG2 and vimentin in these tumors. In summary, we demonstrate that loss of Tsc2 in pericytes generates HPC, the first mouse model of HPC reported.
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Affiliation(s)
- Heng Du
- Division of Pulmonary Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - John R Dreier
- Division of Pulmonary Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mahsa Zarei
- Division of Pulmonary Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Veterinary Physiology and Pharmacology, Texas A & M University, College Station, TX
| | - Chin-Lee Wu
- Departments of Pathology and Urology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - David J Kwiatkowski
- Division of Pulmonary Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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16
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Tsai PT, Rudolph S, Guo C, Ellegood J, Gibson JM, Schaeffer SM, Mogavero J, Lerch JP, Regehr W, Sahin M. Sensitive Periods for Cerebellar-Mediated Autistic-like Behaviors. Cell Rep 2018; 25:357-367.e4. [PMID: 30304677 PMCID: PMC6226056 DOI: 10.1016/j.celrep.2018.09.039] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/06/2018] [Accepted: 09/12/2018] [Indexed: 02/06/2023] Open
Abstract
Despite a prevalence exceeding 1%, mechanisms underlying autism spectrum disorders (ASDs) are poorly understood, and targeted therapies and guiding parameters are urgently needed. We recently demonstrated that cerebellar dysfunction is sufficient to generate autistic-like behaviors in a mouse model of tuberous sclerosis complex (TSC). Here, using the mechanistic target of rapamycin (mTOR)-specific inhibitor rapamycin, we define distinct sensitive periods for treatment of autistic-like behaviors with sensitive periods extending into adulthood for social behaviors. We identify cellular and electrophysiological parameters that may contribute to behavioral rescue, with rescue of Purkinje cell survival and excitability corresponding to social behavioral rescue. In addition, using anatomic and diffusion-based MRI, we identify structural changes in cerebellar domains implicated in ASD that correlate with sensitive periods of specific autism-like behaviors. These findings thus not only define treatment parameters into adulthood, but also support a mechanistic basis for the targeted rescue of autism-related behaviors.
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Affiliation(s)
- Peter T Tsai
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA.
| | | | - Chong Guo
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Kids, Toronto, ON, Canada
| | - Jennifer M Gibson
- Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Samantha M Schaeffer
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jazmin Mogavero
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jason P Lerch
- Mouse Imaging Centre, Hospital for Sick Kids, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Wade Regehr
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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17
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18
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mTOR Signaling and Neural Stem Cells: The Tuberous Sclerosis Complex Model. Int J Mol Sci 2018; 19:ijms19051474. [PMID: 29772672 PMCID: PMC5983755 DOI: 10.3390/ijms19051474] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/04/2018] [Accepted: 05/11/2018] [Indexed: 12/24/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR), a serine-threonine kinase, plays a pivotal role in regulating cell growth and proliferation. Notably, a great deal of evidence indicates that mTOR signaling is also crucial in controlling proliferation and differentiation of several stem cell compartments. Consequently, dysregulation of the mTOR pathway is often associated with a variety of disease, such as cancer and metabolic and genetic disorders. For instance, hyperactivation of mTORC1 in neural stem cells (NSCs) is associated with the insurgence of neurological manifestation characterizing tuberous sclerosis complex (TSC). In this review, we survey the recent contributions of TSC physiopathology studies to understand the role of mTOR signaling in both neurogenesis and tumorigenesis and discuss how these new insights can contribute to developing new therapeutic strategies for neurological diseases and cancer.
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19
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mGluR5 Modulation of Behavioral and Epileptic Phenotypes in a Mouse Model of Tuberous Sclerosis Complex. Neuropsychopharmacology 2018; 43:1457-1465. [PMID: 29206810 PMCID: PMC5916364 DOI: 10.1038/npp.2017.295] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/03/2017] [Accepted: 11/28/2017] [Indexed: 12/13/2022]
Abstract
Drugs targeting metabotropic glutamate receptor 5 (mGluR5) have therapeutic potential in autism spectrum disorders (ASD), including tuberous sclerosis complex (TSC). The question whether inhibition or potentiation of mGluR5 could be beneficial depends, among other factors, on the specific indication. To facilitate the development of mGluR5 treatment strategies, we tested the therapeutic utility of mGluR5 negative and positive allosteric modulators (an mGluR5 NAM and PAM) for TSC, using a mutant mouse model with neuronal loss of Tsc2 that demonstrates disease-related phenotypes, including behavioral symptoms of ASD and epilepsy. This model uniquely enables the in vivo characterization and rescue of the electrographic seizures associated with TSC. We demonstrate that inhibition of mGluR5 corrects hyperactivity, seizures, and elevated de novo synaptic protein synthesis. Conversely, positive allosteric modulation of mGluR5 results in the exacerbation of hyperactivity and epileptic phenotypes. The data suggest a meaningful therapeutic potential for mGluR5 NAMs in TSC, which warrants clinical exploration and the continued development of mGluR5 therapies.
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20
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Yuskaitis CJ, Jones BM, Wolfson RL, Super CE, Dhamne SC, Rotenberg A, Sabatini DM, Sahin M, Poduri A. A mouse model of DEPDC5-related epilepsy: Neuronal loss of Depdc5 causes dysplastic and ectopic neurons, increased mTOR signaling, and seizure susceptibility. Neurobiol Dis 2017; 111:91-101. [PMID: 29274432 DOI: 10.1016/j.nbd.2017.12.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/27/2017] [Accepted: 12/19/2017] [Indexed: 12/15/2022] Open
Abstract
DEPDC5 is a newly identified epilepsy-related gene implicated in focal epilepsy, brain malformations, and Sudden Unexplained Death in Epilepsy (SUDEP). In vitro, DEPDC5 negatively regulates amino acid sensing by the mTOR complex 1 (mTORC1) pathway, but the role of DEPDC5 in neurodevelopment and epilepsy has not been described. No animal model of DEPDC5-related epilepsy has recapitulated the neurological phenotypes seen in patients, and germline knockout rodent models are embryonic lethal. Here, we establish a neuron-specific Depdc5 conditional knockout mouse by cre-recombination under the Synapsin1 promotor. Depdc5flox/flox-Syn1Cre (Depdc5cc+) mice survive to adulthood with a progressive neurologic phenotype that includes motor abnormalities (i.e., hind limb clasping) and reduced survival compared to littermate control mice. Depdc5cc+ mice have larger brains with increased cortical neuron size and dysplastic neurons throughout the cortex, comparable to the abnormal neurons seen in human focal cortical dysplasia specimens. Depdc5 results in constitutive mTORC1 hyperactivation exclusively in neurons as measured by the increased phosphorylation of the downstream ribosomal protein S6. Despite a lack of increased mTORC1 signaling within astrocytes, Depdc5cc+ brains show reactive astrogliosis. We observed two Depdc5cc+ mice to have spontaneous seizures, including a terminal seizure. We demonstrate that as a group Depdc5cc+ mice have lowered seizure thresholds, as evidenced by decreased latency to seizures after chemoconvulsant injection and increased mortality from pentylenetetrazole-induced seizures. In summary, our neuron-specific Depdc5 knockout mouse model recapitulates clinical, pathological, and biochemical features of human DEPDC5-related epilepsy and brain malformations. We thereby present an important model in which to study targeted therapeutic strategies for DEPDC5-related conditions.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Brandon M Jones
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Rachel L Wolfson
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Chloe E Super
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Sameer C Dhamne
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Alexander Rotenberg
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Neuromodulation Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research at MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute, 415 Main Street, Cambridge, MA 02142, USA
| | - Mustafa Sahin
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.
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21
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Stoodley CJ, D'Mello AM, Ellegood J, Jakkamsetti V, Liu P, Nebel MB, Gibson JM, Kelly E, Meng F, Cano CA, Pascual JM, Mostofsky SH, Lerch JP, Tsai PT. Altered cerebellar connectivity in autism and cerebellar-mediated rescue of autism-related behaviors in mice. Nat Neurosci 2017; 20:1744-1751. [PMID: 29184200 PMCID: PMC5867894 DOI: 10.1038/s41593-017-0004-1] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 09/11/2017] [Indexed: 01/12/2023]
Abstract
Cerebellar abnormalities, particularly in Right Crus I (RCrusI), are consistently reported in autism spectrum disorders (ASD). Although RCrusI is functionally connected with ASD-implicated circuits, the contribution of RCrusI dysfunction to ASD remains unclear. Here neuromodulation of RCrusI in neurotypical humans resulted in altered functional connectivity with the inferior parietal lobule, and children with ASD showed atypical functional connectivity in this circuit. Atypical RCrusI-inferior parietal lobule structural connectivity was also evident in the Purkinje neuron (PN) TscI ASD mouse model. Additionally, chemogenetically mediated inhibition of RCrusI PN activity in mice was sufficient to generate ASD-related social, repetitive, and restricted behaviors, while stimulation of RCrusI PNs rescued social impairment in the PN TscI ASD mouse model. Together, these studies reveal important roles for RCrusI in ASD-related behaviors. Further, the rescue of social behaviors in an ASD mouse model suggests that investigation of the therapeutic potential of cerebellar neuromodulation in ASD may be warranted.
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Affiliation(s)
- Catherine J Stoodley
- Department of Psychology and Center for Behavioral Neuroscience, American University, Washington, DC, USA.
| | - Anila M D'Mello
- Department of Psychology and Center for Behavioral Neuroscience, American University, Washington, DC, USA
| | - Jacob Ellegood
- Toronto Mouse Imaging Centre, Hospital for Sick Kids, Toronto, Canada
| | - Vikram Jakkamsetti
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Pei Liu
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mary Beth Nebel
- Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jennifer M Gibson
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elyza Kelly
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Fantao Meng
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Christopher A Cano
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Juan M Pascual
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Stewart H Mostofsky
- Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jason P Lerch
- Toronto Mouse Imaging Centre, Hospital for Sick Kids, Toronto, Canada
| | - Peter T Tsai
- The Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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22
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Kim KC, Cho KS, Yang SM, Gonzales EL, Valencia S, Eun PH, Choi CS, Mabunga DF, Kim JW, Noh JK, Kim HJ, Jeon SJ, Han SH, Bahn GH, Shin CY. Sex Differences in Autism-Like Behavioral Phenotypes and Postsynaptic Receptors Expression in the Prefrontal Cortex of TERT Transgenic Mice. Biomol Ther (Seoul) 2017; 25:374-382. [PMID: 28208013 PMCID: PMC5499615 DOI: 10.4062/biomolther.2016.242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 11/24/2016] [Accepted: 12/06/2016] [Indexed: 11/05/2022] Open
Abstract
Autism spectrum disorder (ASD) remains unexplained and untreated despite the high attention of research in recent years. Aside from its various characteristics is the baffling male preponderance over the female population. Using a validated animal model of ASD which is the telomerase reverse transcriptase overexpressing mice (TERT-tg), we conducted ASD-related behavioral assessments and protein expression experiments to mark the difference between male and females of this animal model. After statistically analyzing the results, we found significant effects of TERT overexpression in sociability, social novelty preference, anxiety, nest building, and electroseizure threshold in the males but not their female littermates. Along these differences are the male-specific increased expressions of postsynaptic proteins which are the NMDA and AMPA receptors in the prefrontal cortex. The vGluT1 presynaptic proteins, but not GAD, were upregulated in both sexes of TERT-tg mice, although it is more significantly pronounced in the male group. Here, we confirmed that the behavioral effect of TERT overexpression in mice was male-specific, suggesting that the aberration of this gene and its downstream pathways preferentially affect the functional development of the male brain, consistent with the male preponderance in ASD.
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Affiliation(s)
- Ki Chan Kim
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Kyu Suk Cho
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Sung Min Yang
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Edson Luck Gonzales
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Schley Valencia
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Pyeong Hwa Eun
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Chang Soon Choi
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Darine Froy Mabunga
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Ji-Woon Kim
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Judy Kyoungju Noh
- College of Human Ecology, Cornell University, Ithaca, New York 14853, United States of America
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, School of Pharmacy, Sahmyook University, Seoul 01795, Republic of Korea
| | - Se Jin Jeon
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seol-Heui Han
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
| | - Geon Ho Bahn
- Department of Neuropsychiatry, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Chan Young Shin
- Center for Neuroscience Research, SMART Institute of Advanced Biomedical Sciences, Konkuk University, Seoul 05029, Republic of Korea
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23
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Switon K, Kotulska K, Janusz-Kaminska A, Zmorzynska J, Jaworski J. Molecular neurobiology of mTOR. Neuroscience 2017; 341:112-153. [PMID: 27889578 DOI: 10.1016/j.neuroscience.2016.11.017] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 01/17/2023]
Abstract
Mammalian/mechanistic target of rapamycin (mTOR) is a serine-threonine kinase that controls several important aspects of mammalian cell function. mTOR activity is modulated by various intra- and extracellular factors; in turn, mTOR changes rates of translation, transcription, protein degradation, cell signaling, metabolism, and cytoskeleton dynamics. mTOR has been repeatedly shown to participate in neuronal development and the proper functioning of mature neurons. Changes in mTOR activity are often observed in nervous system diseases, including genetic diseases (e.g., tuberous sclerosis complex, Pten-related syndromes, neurofibromatosis, and Fragile X syndrome), epilepsy, brain tumors, and neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, and Huntington's disease). Neuroscientists only recently began deciphering the molecular processes that are downstream of mTOR that participate in proper function of the nervous system. As a result, we are gaining knowledge about the ways in which aberrant changes in mTOR activity lead to various nervous system diseases. In this review, we provide a comprehensive view of mTOR in the nervous system, with a special focus on the neuronal functions of mTOR (e.g., control of translation, transcription, and autophagy) that likely underlie the contribution of mTOR to nervous system diseases.
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Affiliation(s)
- Katarzyna Switon
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, Warsaw 04-730, Poland
| | | | - Justyna Zmorzynska
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Jacek Jaworski
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland.
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24
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Switon K, Kotulska K, Janusz-Kaminska A, Zmorzynska J, Jaworski J. Tuberous sclerosis complex: From molecular biology to novel therapeutic approaches. IUBMB Life 2016; 68:955-962. [PMID: 27797139 DOI: 10.1002/iub.1579] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 10/09/2016] [Indexed: 12/20/2022]
Abstract
Tuberous sclerosis complex (TSC) is a rare multi-system disorder, primary manifestations of which are benign tumors and lesions in various organs of the body, including the brain. TSC patients often suffer from epilepsy, mental retardation, and autism spectrum disorder (ASD). Therefore, TSC serves as a model of epilepsy, ASD, and tumorigenesis. TSC is caused by the lack of functional Tsc1-Tsc2 complex, which serves as a major cellular inhibitor of mammalian Target of Rapamycin Complex 1 (mTORC1). mTORC1 is a kinase controlling most of anabolic processes in eukaryotic cells. Consequently, mTORC1 inhibitors, such as rapamycin, serve as experimental or already approved drugs for several TSC symptoms. However, rapalogs, although quite effective, need to be administered chronically and likely for a lifetime, since therapy discontinuation results in tumor regrowth and epilepsy recurrence. Recent studies revealed that metabolism and excitability (in the case of neurons) of cells lacking Tsc1-Tsc2 complex are changed, and these features may potentially be used to treat some of TSC symptoms. In this review, we first provide basic facts about TSC and its molecular background, to next discuss the newest findings in TSC cell biology that can be used to improve existing therapies of TSC and other diseases linked to mTORC1 hyperactivation. © 2016 IUBMB Life, 68(12):955-962, 2016.
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Affiliation(s)
- Katarzyna Switon
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Aleksandra Janusz-Kaminska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Justyna Zmorzynska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Jacek Jaworski
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
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25
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Sahin M, Henske EP, Manning BD, Ess KC, Bissler JJ, Klann E, Kwiatkowski DJ, Roberds SL, Silva AJ, Hillaire-Clarke CS, Young LR, Zervas M, Mamounas LA. Advances and Future Directions for Tuberous Sclerosis Complex Research: Recommendations From the 2015 Strategic Planning Conference. Pediatr Neurol 2016; 60:1-12. [PMID: 27267556 PMCID: PMC4921275 DOI: 10.1016/j.pediatrneurol.2016.03.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 03/24/2016] [Indexed: 11/17/2022]
Abstract
On March 10 to March 12, 2015, the National Institute of Neurological Disorders and Stroke and the Tuberous Sclerosis Alliance sponsored a workshop in Bethesda, Maryland, to assess progress and new opportunities for research in tuberous sclerosis complex with the goal of updating the 2003 Research Plan for Tuberous Sclerosis (http://www.ninds.nih.gov/about_ninds/plans/tscler_research_plan.htm). In addition to the National Institute of Neurological Disorders and Stroke and Tuberous Sclerosis Alliance, participants in the strategic planning effort and workshop included representatives from six other Institutes of the National Institutes of Health, the Department of Defense Tuberous Sclerosis Complex Research Program, and a broad cross-section of basic scientists and clinicians with expertise in tuberous sclerosis complex along with representatives from the pharmaceutical industry. Here we summarize the outcomes from the extensive premeeting deliberations and final workshop recommendations, including (1) progress in the field since publication of the initial 2003 research plan for tuberous sclerosis complex, (2) the key gaps, needs, and challenges that hinder progress in tuberous sclerosis complex research, and (3) a new set of research priorities along with specific recommendations for addressing the major challenges in each priority area. The new research plan is organized around both short-term and long-term goals with the expectation that progress toward specific objectives can be achieved within a five to ten year time frame.
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Affiliation(s)
- Mustafa Sahin
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Elizabeth P Henske
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Kevin C Ess
- Vanderbilt Kennedy Center for Research on Human Development, Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - John J Bissler
- University of Tennessee Health Science Center, Le Bonheur Children's Hospital and St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York
| | - David J Kwiatkowski
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Alcino J Silva
- Departments of Neurobiology, Psychiatry and Psychology, Integrative Center for Learning and Memory, Brain Research Institute, University of California at Los Angeles, Los Angeles, California
| | - Coryse St Hillaire-Clarke
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Lisa R Young
- Division of Pulmonary Medicine, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee; Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mark Zervas
- Department of Neuroscience, Amgen Inc, Cambridge, Massachusetts
| | - Laura A Mamounas
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
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26
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Ben-Sahra I, Hoxhaj G, Ricoult SJH, Asara JM, Manning BD. mTORC1 induces purine synthesis through control of the mitochondrial tetrahydrofolate cycle. Science 2016; 351:728-733. [PMID: 26912861 DOI: 10.1126/science.aad0489] [Citation(s) in RCA: 536] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In response to growth signals, mechanistic target of rapamycin complex 1 (mTORC1) stimulates anabolic processes underlying cell growth. We found that mTORC1 increases metabolic flux through the de novo purine synthesis pathway in various mouse and human cells, thereby influencing the nucleotide pool available for nucleic acid synthesis. mTORC1 had transcriptional effects on multiple enzymes contributing to purine synthesis, with expression of the mitochondrial tetrahydrofolate (mTHF) cycle enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) being closely associated with mTORC1 signaling in both normal and cancer cells. MTHFD2 expression and purine synthesis were stimulated by activating transcription factor 4 (ATF4), which was activated by mTORC1 independent of its canonical induction downstream of eukaryotic initiation factor 2α eIF2α phosphorylation. Thus, mTORC1 stimulates the mTHF cycle, which contributes one-carbon units to enhance production of purine nucleotides in response to growth signals.
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Affiliation(s)
- Issam Ben-Sahra
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115 USA
| | - Gerta Hoxhaj
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115 USA
| | - Stéphane J H Ricoult
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115 USA
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02115 USA
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115 USA
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27
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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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28
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Davis PE, Peters JM, Krueger DA, Sahin M. Tuberous Sclerosis: A New Frontier in Targeted Treatment of Autism. Neurotherapeutics 2015; 12:572-83. [PMID: 25986747 PMCID: PMC4489948 DOI: 10.1007/s13311-015-0359-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder with a high prevalence of autism spectrum disorder (ASD). Tremendous progress in understanding the pathogenesis of TSC has been made in recent years, along with initial trials of medical treatment aimed specifically at the underlying mechanism of the disorder. At the cellular level, loss of TSC1 or TSC2 results in upregulation of the mechanistic target of rapamycin (mTOR) pathway. At the circuitry level, TSC and mTOR play crucial roles in axonal, dendritic, and synaptic development and function. In this review, we discuss the molecular mechanism underlying TSC, and how this disease results in aberrant neural connectivity at multiple levels in the central nervous system, leading to ASD symptoms. We then review recent advances in mechanism-based treatments of TSC, and the promise that these treatments provide for future mechanism-based treatment of ASD. Because of these recent advances, TSC represents an ideal model for how to make progress in understanding and treating the mechanisms that underlie ASD in general.
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Affiliation(s)
- Peter E. Davis
- />Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, 02115 MA USA
| | - Jurriaan M. Peters
- />Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, 02115 MA USA
| | - Darcy A. Krueger
- />Division of Neurology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Mustafa Sahin
- />Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, 02115 MA USA
- />F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
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29
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Delaney SP, Julian LM, Stanford WL. The neural crest lineage as a driver of disease heterogeneity in Tuberous Sclerosis Complex and Lymphangioleiomyomatosis. Front Cell Dev Biol 2014; 2:69. [PMID: 25505789 PMCID: PMC4243694 DOI: 10.3389/fcell.2014.00069] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 11/02/2014] [Indexed: 12/20/2022] Open
Abstract
Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease, best characterized by the formation of proliferative nodules that express smooth muscle and melanocytic antigens within the lung parenchyma, leading to progressive destruction of lung tissue and function. The pathological basis of LAM is associated with Tuberous Sclerosis Complex (TSC), a multi-system disorder marked by low-grade tumors in the brain, kidneys, heart, eyes, lung and skin, arising from inherited or spontaneous germ-line mutations in either of the TSC1 or TSC2 genes. LAM can develop either in a patient with TSC (TSC-LAM) or spontaneously (S-LAM), and it is clear that the majority of LAM lesions of both forms are characterized by an inactivating mutation in either TSC1 or TSC2, as in TSC. Despite this genetic commonality, there is considerable heterogeneity in the tumor spectrum of TSC and LAM patients, the basis for which is currently unknown. There is extensive clinical evidence to suggest that the cell of origin for LAM, as well as many of the TSC-associated tumors, is a neural crest cell, a highly migratory cell type with extensive multi-lineage potential. Here we explore the hypothesis that the types of tumors that develop and the tissues that are affected in TSC and LAM are dictated by the developmental timing of TSC gene mutations, which determines the identities of the affected cell types and the size of downstream populations that acquire a mutation. We further discuss the evidence to support a neural crest origin for LAM and TSC tumors, and propose approaches for generating humanized models of TSC and LAM that will allow cell of origin theories to be experimentally tested. Identifying the cell of origin and developing appropriate humanized models is necessary to truly understand LAM and TSC pathology and to establish effective and long-lasting therapeutic approaches for these patients.
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Affiliation(s)
- Sean P Delaney
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute Ottawa, ON, Canada ; Faculty of Graduate and Postdoctoral Studies, University of Ottawa Ottawa, ON, Canada ; Department of Cellular and Molecular Medicine, University of Ottawa Ottawa, ON, Canada
| | - Lisa M Julian
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute Ottawa, ON, Canada ; Faculty of Graduate and Postdoctoral Studies, University of Ottawa Ottawa, ON, Canada
| | - William L Stanford
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute Ottawa, ON, Canada ; Faculty of Graduate and Postdoctoral Studies, University of Ottawa Ottawa, ON, Canada ; Department of Cellular and Molecular Medicine, University of Ottawa Ottawa, ON, Canada ; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa Ottawa, ON, Canada
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30
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Xu K, Liu P, Wei W. mTOR signaling in tumorigenesis. Biochim Biophys Acta Rev Cancer 2014; 1846:638-54. [PMID: 25450580 DOI: 10.1016/j.bbcan.2014.10.007] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/23/2014] [Accepted: 10/25/2014] [Indexed: 12/25/2022]
Abstract
mTOR (the mechanistic target of rapamycin) is an atypical serine/threonine kinase involved in regulating major cellular functions including growth and proliferation. Deregulation of the mTOR signaling pathway is one of the most commonly observed pathological alterations in human cancers. To this end, oncogenic activation of the mTOR signaling pathway contributes to cancer cell growth, proliferation and survival, highlighting the potential for targeting the oncogenic mTOR pathway members as an effective anti-cancer strategy. In order to do so, a thorough understanding of the physiological roles of key mTOR signaling pathway components and upstream regulators would guide future targeted therapies. Thus, in this review, we summarize available genetic mouse models for mTORC1 and mTORC2 components, as well as characterized mTOR upstream regulators and downstream targets, and assign a potential oncogenic or tumor suppressive role for each evaluated molecule. Together, our work will not only facilitate the current understanding of mTOR biology and possible future research directions, but more importantly, provide a molecular basis for targeted therapies aiming at key oncogenic members along the mTOR signaling pathway.
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Affiliation(s)
- Kai Xu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Pengda Liu
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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31
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Subchronic treatment of donepezil rescues impaired social, hyperactive, and stereotypic behavior in valproic acid-induced animal model of autism. PLoS One 2014; 9:e104927. [PMID: 25133713 PMCID: PMC4136791 DOI: 10.1371/journal.pone.0104927] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 07/16/2014] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is a group of pervasive developmental disorders with core symptoms such as sociability deficit, language impairment, and repetitive/restricted behaviors. Although worldwide prevalence of ASD has been increased continuously, therapeutic agents to ameliorate the core symptoms especially social deficits, are very limited. In this study, we investigated therapeutic potential of donepezil for ASD using valproic acid-induced autistic animal model (VPA animal model). We found that prenatal exposure of valproic acid (VPA) induced dysregulation of cholinergic neuronal development, most notably the up-regulation of acetylcholinesterase (AChE) in the prefrontal cortex of affected rat and mouse offspring. Similarly, differentiating cortical neural progenitor cell in culture treated with VPA showed increased expression of AChE in vitro. Chromatin precipitation experiments revealed that acetylation of histone H3 bound to AChE promoter region was increased by VPA. In addition, other histone deacetyalse inhibitors (HDACIs) such as trichostatin A and sodium butyrate also increased the expression of AChE in differentiating neural progenitor cells suggesting the essential role of HDACIs in the regulation of AChE expression. For behavioral analysis, we injected PBS or donepezil (0.3 mg/kg) intraperitoneally to control and VPA mice once daily from postnatal day 14 all throughout the experiment. Subchronic treatment of donepezil improved sociability and prevented repetitive behavior and hyperactivity of VPA-treated mice offspring. Taken together, these results provide evidence that dysregulation of ACh system represented by the up-regulation of AChE may serve as an effective pharmacological therapeutic target against autistic behaviors in VPA animal model of ASD, which should be subjected for further investigation to verify the clinical relevance.
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32
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Coordinated regulation of protein synthesis and degradation by mTORC1. Nature 2014; 513:440-3. [PMID: 25043031 DOI: 10.1038/nature13492] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/15/2014] [Indexed: 01/20/2023]
Abstract
Eukaryotic cells coordinately control anabolic and catabolic processes to maintain cell and tissue homeostasis. Mechanistic target of rapamycin complex 1 (mTORC1) promotes nutrient-consuming anabolic processes, such as protein synthesis. Here we show that as well as increasing protein synthesis, mTORC1 activation in mouse and human cells also promotes an increased capacity for protein degradation. Cells with activated mTORC1 exhibited elevated levels of intact and active proteasomes through a global increase in the expression of genes encoding proteasome subunits. The increase in proteasome gene expression, cellular proteasome content, and rates of protein turnover downstream of mTORC1 were all dependent on induction of the transcription factor nuclear factor erythroid-derived 2-related factor 1 (NRF1; also known as NFE2L1). Genetic activation of mTORC1 through loss of the tuberous sclerosis complex tumour suppressors, TSC1 or TSC2, or physiological activation of mTORC1 in response to growth factors or feeding resulted in increased NRF1 expression in cells and tissues. We find that this NRF1-dependent elevation in proteasome levels serves to increase the intracellular pool of amino acids, which thereby influences rates of new protein synthesis. Therefore, mTORC1 signalling increases the efficiency of proteasome-mediated protein degradation for both quality control and as a mechanism to supply substrate for sustained protein synthesis.
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Ruppe V, Dilsiz P, Reiss CS, Carlson C, Devinsky O, Zagzag D, Weiner HL, Talos DM. Developmental brain abnormalities in tuberous sclerosis complex: A comparative tissue analysis of cortical tubers and perituberal cortex. Epilepsia 2014; 55:539-50. [DOI: 10.1111/epi.12545] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Véronique Ruppe
- Department of Neurology; School of Medicine; New York University; New York New York U.S.A
| | - Pelin Dilsiz
- Department of Neurology; School of Medicine; New York University; New York New York U.S.A
| | - Carol Shoshkes Reiss
- Department of Biology and Neural Science; New York University; New York New York U.S.A
| | - Chad Carlson
- Department of Neurology; School of Medicine; New York University; New York New York U.S.A
| | - Orrin Devinsky
- Department of Neurology; School of Medicine; New York University; New York New York U.S.A
- Department of Neurosurgery; School of Medicine; New York University; New York New York U.S.A
- Department of Psychiatry; School of Medicine; New York University; New York New York U.S.A
| | - David Zagzag
- Department of Neurosurgery; School of Medicine; New York University; New York New York U.S.A
- Department of Pathology; School of Medicine; New York University; New York New York U.S.A
| | - Howard L. Weiner
- Department of Neurosurgery; School of Medicine; New York University; New York New York U.S.A
| | - Delia M. Talos
- Department of Neurology; School of Medicine; New York University; New York New York U.S.A
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Prabhakar S, Goto J, Zuang X, Sena-Esteves M, Bronson R, Brockmann J, Gianni D, Wojtkiewicz GR, Chen JW, Stemmer-Rachamimov A, Kwiatkowski DJ, Breakefield XO. Stochastic model of Tsc1 lesions in mouse brain. PLoS One 2013; 8:e64224. [PMID: 23696872 PMCID: PMC3655945 DOI: 10.1371/journal.pone.0064224] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/10/2013] [Indexed: 11/18/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder due to mutations in either TSC1 or TSC2 that affects many organs with hamartomas and tumors. TSC-associated brain lesions include subependymal nodules, subependymal giant cell astrocytomas and tubers. Neurologic manifestations in TSC comprise a high frequency of mental retardation and developmental disorders including autism, as well as epilepsy. Here, we describe a new mouse model of TSC brain lesions in which complete loss of Tsc1 is achieved in multiple brain cell types in a stochastic pattern. Injection of an adeno-associated virus vector encoding Cre recombinase into the cerebral ventricles of mice homozygous for a Tsc1 conditional allele on the day of birth led to reduced survival, and pathologic findings of enlarged neurons, cortical heterotopias, subependymal nodules, and hydrocephalus. The severity of clinical and pathologic findings as well as survival was shown to be dependent upon the dose and serotype of Cre virus injected. Although several other models of TSC brain disease exist, this model is unique in that the pathology reflects a variety of TSC-associated lesions involving different numbers and types of cells. This model provides a valuable and unique addition for therapeutic assessment.
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Affiliation(s)
- Shilpa Prabhakar
- Molecular Neurogenetics Unit, Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital, and Program in Neuroscience, Medical School, Boston, Massachusetts, United States of America
| | - June Goto
- Translational Medicine Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xuan Zuang
- Molecular Neurogenetics Unit, Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital, and Program in Neuroscience, Medical School, Boston, Massachusetts, United States of America
| | - Miguel Sena-Esteves
- Neurology Department, Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Roderick Bronson
- Rodent Histopathology Core Facility, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jillian Brockmann
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Davide Gianni
- Neurology Department, Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Gregory R. Wojtkiewicz
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - John W. Chen
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Anat Stemmer-Rachamimov
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - David J. Kwiatkowski
- Translational Medicine Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xandra O. Breakefield
- Molecular Neurogenetics Unit, Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital, and Program in Neuroscience, Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Crino PB. Evolving neurobiology of tuberous sclerosis complex. Acta Neuropathol 2013; 125:317-32. [PMID: 23386324 DOI: 10.1007/s00401-013-1085-x] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/14/2013] [Accepted: 01/19/2013] [Indexed: 11/30/2022]
Abstract
Over the past decade, there have been numerous advances in our understanding of the molecular pathogenesis of tuberous sclerosis complex (TSC). Following the identification of the TSC1 and TSC2 genes, a link to regulatory control of the mammalian target of rapamycin (mTOR) signaling pathway has paved the way for new therapeutic interventions, and now even approved therapies for TSC. Gene identification has permitted establishment of cell lines and conditional knockout mouse strains to assay how abnormalities in brain structure lead to enhanced excitability, seizures, cognitive disabilities, and other neuropsychological disorders in TSC. Furthermore, work in in vitro systems and analysis of rodent models and human tissue has allowed investigators to study how brain lesions form in TSC. Evolving questions over the next decade include understanding the high clinical variability of TSC, defining why there is a lack of clear genotype-phenotype correlations, and identifying biomarkers for prognosis and stratification. The study of TSC has in many ways reflected a paradigm "bench-to-bedside" success story that serves as a model of many other neurological disorders.
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Affiliation(s)
- Peter B Crino
- Department of Neurology, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, 6th Floor Medical Education and Research Building, 3500N. Broad Street, Philadelphia, PA 19140-4106, USA.
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Feliciano DM, Lin TV, Hartman NW, Bartley CM, Kubera C, Hsieh L, Lafourcade C, O'Keefe RA, Bordey A. A circuitry and biochemical basis for tuberous sclerosis symptoms: from epilepsy to neurocognitive deficits. Int J Dev Neurosci 2013; 31:667-78. [PMID: 23485365 DOI: 10.1016/j.ijdevneu.2013.02.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/15/2013] [Accepted: 02/18/2013] [Indexed: 01/17/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant monogenetic disorder that is characterized by the formation of benign tumors in several organs as well as brain malformations and neuronal defects. TSC is caused by inactivating mutations in one of two genes, TSC1 and TSC2, resulting in increased activity of the mammalian Target of Rapamycin (mTOR). Here, we explore the cytoarchitectural and functional CNS aberrations that may account for the neurological presentations of TSC, notably seizures, hydrocephalus, and cognitive and psychological impairments. In particular, recent mouse models of brain lesions are presented with an emphasis on using electroporation to allow the generation of discrete lesions resulting from loss of heterozygosity during perinatal development. Cortical lesions are thought to contribute to epileptogenesis and worsening of cognitive defects. However, it has recently been suggested that being born with a mutant allele without loss of heterozygosity and associated cortical lesions is sufficient to generate cognitive and neuropsychiatric problems. We will thus discuss the function of mTOR hyperactivity on neuronal circuit formation and the potential consequences of being born heterozygous on neuronal function and the biochemistry of synaptic plasticity, the cellular substrate of learning and memory. Ultimately, a major goal of TSC research is to identify the cellular and molecular mechanisms downstream of mTOR underlying the neurological manifestations observed in TSC patients and identify novel therapeutic targets to prevent the formation of brain lesions and restore neuronal function.
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Affiliation(s)
- David M Feliciano
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
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Tsai PT, Greene-Colozzi E, Goto J, Anderl S, Kwiatkowski DJ, Sahin M. Prenatal rapamycin results in early and late behavioral abnormalities in wildtype C57BL/6 mice. Behav Genet 2012; 43:51-9. [PMID: 23229624 DOI: 10.1007/s10519-012-9571-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 11/29/2012] [Indexed: 11/28/2022]
Abstract
Mammalian target of rapamycin (mTOR) signaling has been shown to be deregulated in a number of genetic, neurodevelopmental disorders including Tuberous Sclerosis Complex, Neurofibromatosis, Fragile X, and Rett syndromes. As a result, mTOR inhibitors, such as rapamycin and its analogs, offer potential therapeutic avenues for these disorders. Some of these disorders-such as Tuberous Sclerosis Complex-can be diagnosed prenatally. Thus, prenatal administration of these inhibitors could potentially prevent the development of the devastating symptoms associated with these disorders. To assess the possible detrimental effects of prenatal rapamycin treatment, we evaluated both early and late behavioral effects of a single rapamycin treatment at embryonic day 16.5 in wildtype C57Bl/6 mice. This treatment adversely impacted early developmental milestones as well as motor function in adult animals. Rapamycin also resulted in anxiety-like behaviors during both early development and adulthood but did not affect adult social behaviors. Together, these results indicate that a single, prenatal rapamycin treatment not only adversely affects early postnatal development but also results in long lasting negative effects, persisting into adulthood. These findings are of importance in considering prenatal administration of rapamycin and related drugs in the treatment of patients with neurogenetic, neurodevelopmental disorders.
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Affiliation(s)
- Peter T Tsai
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, 300 Longwood Avenue CLS13074, Boston, MA 02115, USA
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