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Abstract
During evolution, duplication of subnuclei generates broader cerebellar projections
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Affiliation(s)
- Mary E Hatten
- Laboratory of Developmental Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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52
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Leonard CE, Baydyuk M, Stepler MA, Burton DA, Donoghue MJ. EphA7 isoforms differentially regulate cortical dendrite development. PLoS One 2020; 15:e0231561. [PMID: 33275600 PMCID: PMC7717530 DOI: 10.1371/journal.pone.0231561] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 11/22/2020] [Indexed: 02/06/2023] Open
Abstract
The shape of a neuron facilitates its functionality within neural circuits. Dendrites integrate incoming signals from axons, receiving excitatory input onto small protrusions called dendritic spines. Therefore, understanding dendritic growth and development is fundamental for discerning neural function. We previously demonstrated that EphA7 receptor signaling during cortical development impacts dendrites in two ways: EphA7 restricts dendritic growth early and promotes dendritic spine formation later. Here, the molecular basis for this shift in EphA7 function is defined. Expression analyses reveal that EphA7 full-length (EphA7-FL) and truncated (EphA7-T1; lacking kinase domain) isoforms are dynamically expressed in the developing cortex. Peak expression of EphA7-FL overlaps with dendritic elaboration around birth, while highest expression of EphA7-T1 coincides with dendritic spine formation in early postnatal life. Overexpression studies in cultured neurons demonstrate that EphA7-FL inhibits both dendritic growth and spine formation, while EphA7-T1 increases spine density. Furthermore, signaling downstream of EphA7 shifts during development, such that in vivo inhibition of mTOR by rapamycin in EphA7-mutant neurons ameliorates dendritic branching, but not dendritic spine phenotypes. Finally, direct interaction between EphA7-FL and EphA7-T1 is demonstrated in cultured cells, which results in reduction of EphA7-FL phosphorylation. In cortex, both isoforms are colocalized to synaptic fractions and both transcripts are expressed together within individual neurons, supporting a model where EphA7-T1 modulates EphA7-FL repulsive signaling during development. Thus, the divergent functions of EphA7 during cortical dendrite development are explained by the presence of two variants of the receptor.
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Affiliation(s)
- Carrie E. Leonard
- Department of Biology, Georgetown University, Washington, DC, United States of America
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States of America
| | - Maryna Baydyuk
- Department of Biology, Georgetown University, Washington, DC, United States of America
| | - Marissa A. Stepler
- Department of Biology, Georgetown University, Washington, DC, United States of America
| | - Denver A. Burton
- Department of Biology, Georgetown University, Washington, DC, United States of America
| | - Maria J. Donoghue
- Department of Biology, Georgetown University, Washington, DC, United States of America
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States of America
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53
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Basilico B, Morandell J, Novarino G. Molecular mechanisms for targeted ASD treatments. Curr Opin Genet Dev 2020; 65:126-137. [PMID: 32659636 DOI: 10.1016/j.gde.2020.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 12/30/2022]
Abstract
The possibility to generate construct valid animal models enabled the development and testing of therapeutic strategies targeting the core features of autism spectrum disorders (ASDs). At the same time, these studies highlighted the necessity of identifying sensitive developmental time windows for successful therapeutic interventions. Animal and human studies also uncovered the possibility to stratify the variety of ASDs in molecularly distinct subgroups, potentially facilitating effective treatment design. Here, we focus on the molecular pathways emerging as commonly affected by mutations in diverse ASD-risk genes, on their role during critical windows of brain development and the potential treatments targeting these biological processes.
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Affiliation(s)
| | - Jasmin Morandell
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Gaia Novarino
- Institute of Science and Technology Austria, Klosterneuburg, Austria.
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54
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Van Overwalle F, Manto M, Cattaneo Z, Clausi S, Ferrari C, Gabrieli JDE, Guell X, Heleven E, Lupo M, Ma Q, Michelutti M, Olivito G, Pu M, Rice LC, Schmahmann JD, Siciliano L, Sokolov AA, Stoodley CJ, van Dun K, Vandervert L, Leggio M. Consensus Paper: Cerebellum and Social Cognition. CEREBELLUM (LONDON, ENGLAND) 2020; 19:833-868. [PMID: 32632709 PMCID: PMC7588399 DOI: 10.1007/s12311-020-01155-1] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The traditional view on the cerebellum is that it controls motor behavior. Although recent work has revealed that the cerebellum supports also nonmotor functions such as cognition and affect, only during the last 5 years it has become evident that the cerebellum also plays an important social role. This role is evident in social cognition based on interpreting goal-directed actions through the movements of individuals (social "mirroring") which is very close to its original role in motor learning, as well as in social understanding of other individuals' mental state, such as their intentions, beliefs, past behaviors, future aspirations, and personality traits (social "mentalizing"). Most of this mentalizing role is supported by the posterior cerebellum (e.g., Crus I and II). The most dominant hypothesis is that the cerebellum assists in learning and understanding social action sequences, and so facilitates social cognition by supporting optimal predictions about imminent or future social interaction and cooperation. This consensus paper brings together experts from different fields to discuss recent efforts in understanding the role of the cerebellum in social cognition, and the understanding of social behaviors and mental states by others, its effect on clinical impairments such as cerebellar ataxia and autism spectrum disorder, and how the cerebellum can become a potential target for noninvasive brain stimulation as a therapeutic intervention. We report on the most recent empirical findings and techniques for understanding and manipulating cerebellar circuits in humans. Cerebellar circuitry appears now as a key structure to elucidate social interactions.
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Affiliation(s)
- Frank Van Overwalle
- Department of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Mario Manto
- Mediathèque Jean Jacquy, Service de Neurologie, CHU-Charleroi, Charleroi, Belgium
- Service des Neurosciences, Université de Mons, Mons, Belgium
| | - Zaira Cattaneo
- University of Milano-Bicocca, 20126 Milan, Italy
- IRCCS Mondino Foundation, Pavia, Italy
| | - Silvia Clausi
- Ataxia Laboratory, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | | | - John D. E. Gabrieli
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, USA
| | - Xavier Guell
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, USA
- Ataxia Unit, Cognitive Behavioral Neurology Unit, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Elien Heleven
- Department of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Michela Lupo
- Ataxia Laboratory, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Qianying Ma
- Department of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Marco Michelutti
- Service de Neurologie & Neuroscape@NeuroTech Platform, Département des Neurosciences Cliniques, Centre Hospitalier Universitaire Vaudois (CHUV), Service de Neurologie Lausanne, Lausanne, Switzerland
- Department of Neurosciences, University of Padua, Padua, Italy
| | - Giusy Olivito
- Ataxia Laboratory, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Min Pu
- Department of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Laura C. Rice
- Department of Psychology and Department of Neuroscience, American University, Washington, DC USA
| | - Jeremy D. Schmahmann
- Ataxia Unit, Cognitive Behavioral Neurology Unit, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Libera Siciliano
- Program in Behavioral Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Arseny A. Sokolov
- Service de Neurologie & Neuroscape@NeuroTech Platform, Département des Neurosciences Cliniques, Centre Hospitalier Universitaire Vaudois (CHUV), Service de Neurologie Lausanne, Lausanne, Switzerland
- Department of Neurology, University Neurorehabilitation, University Hospital Inselspital, University of Bern, Bern, Switzerland
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London (UCL), London, UK
- Neuroscape Center, Weill Institute for Neurosciences, Department of Neurology, University of California San Francisco, San Francisco, CA USA
| | - Catherine J. Stoodley
- Department of Psychology and Department of Neuroscience, American University, Washington, DC USA
| | - Kim van Dun
- Neurologic Rehabilitation Research, Rehabilitation Research Institute (REVAL), Hasselt University, 3590 Diepenbeek, Belgium
| | - Larry Vandervert
- American Nonlinear Systems, 1529 W. Courtland Avenue, Spokane, WA 99205-2608 USA
| | - Maria Leggio
- Ataxia Laboratory, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
- Department of Psychology, Sapienza University of Rome, Rome, Italy
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55
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UYSAL SP, ŞAHİN M. Tuberous sclerosis: a review of the past, present, and future. Turk J Med Sci 2020; 50:1665-1676. [PMID: 32222129 PMCID: PMC7672342 DOI: 10.3906/sag-2002-133] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 03/22/2020] [Indexed: 11/23/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant, multisystem disorder that is characterized by cellular and tissue dysplasia in several organs. With the advent of genetic and molecular techniques, mutations in the TSC1 or TSC2 genes were discovered to be responsible for mTOR overactivation, which is the underlying mechanism of pathogenesis. TSC is a highly heterogenous clinical entity with variable presentations and severity of disease. The brain, heart, skin, eyes, kidneys, and lungs are commonly involved in this syndrome, with neurologic symptoms comprising a significant source of morbidity and mortality. In 2012, the diagnostic criteria for TSC were revised by the International Tuberous Sclerosis Complex Consensus panel, and genetic testing was incorporated into the guidelines. Early detection of cardiac rhabdomyomas or TSC-associated skin lesions can suggest the diagnosis and underlie the importance of clinical vigilance. Animal studies have demonstrated the benefit of using mTOR inhibitors for various symptoms of TSC, and they have been successfully translated into clinical trials with significant improvement in symptom burden. Subependymal giant cell astrocytomas, renal angiomyolipomas, and epilepsy are the three FDA-approved indications in relation to TSC for the use of everolimus, which is a first generation mTOR inhibitor. Rapamycin has been FDA approved for lymphangioleiomyomatosis. Other TSC symptoms that could potentially benefit from this class of medication are currently under investigation. TSC constitutes a unique combination of protean physical symptoms and neurobehavioral abnormalities. TSC associated neuropsychiatric disorders (TAND), including intellectual disability, mood disorders, and autism spectrum disorder, represent significant challenges but remain underdiagnosed and undertreated. The TAND checklist is a useful tool for routine use in the clinical evaluation of TSC patients. A multidisciplinary treatment plan, based on the specific problems and needs of individuals, is the key to management of this genetic condition. Ongoing research studies have been providing promising leads for developing novel mechanistic strategies to address the pathophysiology of TSC.
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Affiliation(s)
- Sanem Pınar UYSAL
- Department of Neurology, Harvard Medical School, Boston Children’s Hospital, Boston MassachusettsUSA
| | - Mustafa ŞAHİN
- Department of Neurology, Harvard Medical School, Boston Children’s Hospital, Boston MassachusettsUSA
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56
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Yamamoto M, Kim M, Imai H, Itakura Y, Ohtsuki G. Microglia-Triggered Plasticity of Intrinsic Excitability Modulates Psychomotor Behaviors in Acute Cerebellar Inflammation. Cell Rep 2020; 28:2923-2938.e8. [PMID: 31509752 DOI: 10.1016/j.celrep.2019.07.078] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 04/20/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022] Open
Abstract
Cerebellar dysfunction relates to various psychiatric disorders, including autism spectrum and depressive disorders. However, the physiological aspect is less advanced. Here, we investigate the immune-triggered hyperexcitability in the cerebellum on a wider scope. Activated microglia via exposure to bacterial endotoxin lipopolysaccharide or heat-killed Gram-negative bacteria induce a potentiation of the intrinsic excitability in Purkinje neurons, which is suppressed by microglia-activity inhibitor and microglia depletion. An inflammatory cytokine, tumor necrosis factor alpha (TNF-α), released from microglia via toll-like receptor 4, triggers this plasticity. Our two-photon FRET ATP imaging shows an increase in ATP concentration following endotoxin exposure. Both TNF-α and ATP secretion facilitate synaptic transmission. Region-specific inflammation in the cerebellum in vivo shows depression- and autistic-like behaviors. Furthermore, both TNF-α inhibition and microglia depletion revert such behavioral abnormality. Resting-state functional MRI reveals overconnectivity between the inflamed cerebellum and the prefrontal neocortical regions. Thus, immune activity in the cerebellum induces neuronal hyperexcitability and disruption of psychomotor behaviors in animals.
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Affiliation(s)
- Masamichi Yamamoto
- Department of Nephrology, Kyoto University Graduate School of Medicine, Kyoto University Hospital, Shogoin-Kawaramachi-cho, Sakyo-ward, Kyoto 606-8507, Japan
| | - Minsoo Kim
- The Hakubi Center for Advanced Research, Kyoto University, Yoshida, Sakyo-ward, Kyoto 606-8501, Japan; Department of Molecular and Cellular Physiology, Kyoto University Graduate School of Medicine, Yoshida-Konoe-cho, Sakyo-ward, Kyoto 606-8501, Japan
| | - Hirohiko Imai
- Department of Systems Science, Kyoto University Graduate School of Informatics, Yoshida-Honmachi, Sakyo-ward, Kyoto 606-8501, Japan
| | - Yamato Itakura
- Department of Biophysics, Kyoto University Graduate School of Science, Kitashirakawa-Oiwake-cho, Sakyo-ward, Kyoto 606-8502, Japan
| | - Gen Ohtsuki
- The Hakubi Center for Advanced Research, Kyoto University, Yoshida, Sakyo-ward, Kyoto 606-8501, Japan; Department of Biophysics, Kyoto University Graduate School of Science, Kitashirakawa-Oiwake-cho, Sakyo-ward, Kyoto 606-8502, Japan.
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57
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Kelly E, Meng F, Fujita H, Morgado F, Kazemi Y, Rice LC, Ren C, Escamilla CO, Gibson JM, Sajadi S, Pendry RJ, Tan T, Ellegood J, Basson MA, Blakely RD, Dindot SV, Golzio C, Hahn MK, Katsanis N, Robins DM, Silverman JL, Singh KK, Wevrick R, Taylor MJ, Hammill C, Anagnostou E, Pfeiffer BE, Stoodley CJ, Lerch JP, du Lac S, Tsai PT. Regulation of autism-relevant behaviors by cerebellar-prefrontal cortical circuits. Nat Neurosci 2020; 23:1102-1110. [PMID: 32661395 PMCID: PMC7483861 DOI: 10.1038/s41593-020-0665-z] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 06/05/2020] [Indexed: 12/20/2022]
Abstract
Cerebellar dysfunction has been demonstrated in autism spectrum disorders (ASDs); however, the circuits underlying cerebellar contributions to ASD-relevant behaviors remain unknown. In this study, we demonstrated functional connectivity between the cerebellum and the medial prefrontal cortex (mPFC) in mice; showed that the mPFC mediates cerebellum-regulated social and repetitive/inflexible behaviors; and showed disruptions in connectivity between these regions in multiple mouse models of ASD-linked genes and in individuals with ASD. We delineated a circuit from cerebellar cortical areas Right crus 1 (Rcrus1) and posterior vermis through the cerebellar nuclei and ventromedial thalamus and culminating in the mPFC. Modulation of this circuit induced social deficits and repetitive behaviors, whereas activation of Purkinje cells (PCs) in Rcrus1 and posterior vermis improved social preference impairments and repetitive/inflexible behaviors, respectively, in male PC-Tsc1 mutant mice. These data raise the possibility that these circuits might provide neuromodulatory targets for the treatment of ASD.
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Affiliation(s)
- Elyza Kelly
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Fantao Meng
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hirofumi Fujita
- Departments of Otolaryngology-Head and Neck Surgery, Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Felipe Morgado
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Mouse Imaging Centre, Toronto Hospital for Sick Children, Toronto, ON, Canada
| | - Yasaman Kazemi
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laura C Rice
- Department of Neuroscience, Center for Behavioral Neuroscience, American University, Washington, DC, USA
| | - Chongyu Ren
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Christine Ochoa Escamilla
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jennifer M Gibson
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sanaz Sajadi
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Robert J Pendry
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tommy Tan
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jacob Ellegood
- Mouse Imaging Centre, Toronto Hospital for Sick Children, Toronto, ON, Canada
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology and MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Randy D Blakely
- Department of Biomedical Science, Charles E. Schmidt College of Medicine and Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
| | - Scott V Dindot
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Christelle Golzio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire; Centre National de la Recherche Scientifique; Institut National de la Santé et de la Recherche Médicale; Université de Strasbourg, Illkirch, France
| | - Maureen K Hahn
- Department of Biomedical Science, Charles E. Schmidt College of Medicine and Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
| | - Nicholas Katsanis
- ACT-GeM, Department of Human Genetics at Stanley Manne Children's Research Institute; Department of Pediatrics and Cellular and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Diane M Robins
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jill L Silverman
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
| | - Karun K Singh
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Margot J Taylor
- Department of Medical Imaging and Psychology, University of Toronto; Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, USA
| | - Christopher Hammill
- Mouse Imaging Centre, Toronto Hospital for Sick Children, Toronto, ON, Canada
| | - Evdokia Anagnostou
- Department of Pediatrics, University of Toronto, Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON, USA
| | - Brad E Pfeiffer
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Catherine J Stoodley
- Department of Neuroscience, Center for Behavioral Neuroscience, American University, Washington, DC, USA
| | - Jason P Lerch
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Mouse Imaging Centre, Toronto Hospital for Sick Children, Toronto, ON, Canada
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK
| | - Sascha du Lac
- Departments of Otolaryngology-Head and Neck Surgery, Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter T Tsai
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Departments of Psychiatry and Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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58
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Samanta D. An Updated Review of Tuberous Sclerosis Complex-Associated Autism Spectrum Disorder. Pediatr Neurol 2020; 109:4-11. [PMID: 32563542 DOI: 10.1016/j.pediatrneurol.2020.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 01/30/2023]
Abstract
Tuberous sclerosis complex (TSC) is a neurocutaneous disorder caused by mutations of either the TSC1 or TSC2 gene. Various neuropsychiatric features, including autism, are prevalent in TSC. Recently, significant progress has been possible with the prospective calculation of the prevalence of autism in TSC, identification of early clinical and neurophysiological biomarkers to predict autism, and investigation of different therapies to prevent autism in this high-risk population. The author provides a narrative review of recent findings related to biomarkers for diagnosis of autism in TSC, as well as recent studies related to the management of TSC-associated autism. Further sophisticated modeling and analysis are required to understand the role of different models-tuber models, seizures and related neurophysiological factors models, genotype models, and brain connectivity models-to unravel the neurobiological basis of autism in TSC. Early neuropsychologic assessments may be beneficial in this high-risk group. Targeted intervention to improve visual skill, cognition, and fine motor skills with later addition of social skill training can be helpful. Multicenter, prospective studies are ongoing to identify if presymptomatic treatment with vigabatrin in patients with TSC can improve outcomes, including autism. Several studies indicated reasonable safety of everolimus in young children, and its potential application in high-risk infants with TSC, before the closure of the temporal window of permanent changes, maybe undertaken shortly.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
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59
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Novel genetic features of human and mouse Purkinje cell differentiation defined by comparative transcriptomics. Proc Natl Acad Sci U S A 2020; 117:15085-15095. [PMID: 32546527 PMCID: PMC7334519 DOI: 10.1073/pnas.2000102117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Comparative transcriptomics between differentiating human pluripotent stem cells (hPSCs) and developing mouse neurons offers a powerful approach to compare genetic and epigenetic pathways in human and mouse neurons. To analyze human Purkinje cell (PC) differentiation, we optimized a protocol to generate human pluripotent stem cell-derived Purkinje cells (hPSC-PCs) that formed synapses when cultured with mouse cerebellar glia and granule cells and fired large calcium currents, measured with the genetically encoded calcium indicator jRGECO1a. To directly compare global gene expression of hPSC-PCs with developing mouse PCs, we used translating ribosomal affinity purification (TRAP). As a first step, we used Tg(Pcp2-L10a-Egfp) TRAP mice to profile actively transcribed genes in developing postnatal mouse PCs and used metagene projection to identify the most salient patterns of PC gene expression over time. We then created a transgenic Pcp2-L10a-Egfp TRAP hPSC line to profile gene expression in differentiating hPSC-PCs, finding that the key gene expression pathways of differentiated hPSC-PCs most closely matched those of late juvenile mouse PCs (P21). Comparative bioinformatics identified classical PC gene signatures as well as novel mitochondrial and autophagy gene pathways during the differentiation of both mouse and human PCs. In addition, we identified genes expressed in hPSC-PCs but not mouse PCs and confirmed protein expression of a novel human PC gene, CD40LG, expressed in both hPSC-PCs and native human cerebellar tissue. This study therefore provides a direct comparison of hPSC-PC and mouse PC gene expression and a robust method for generating differentiated hPSC-PCs with human-specific gene expression for modeling developmental and degenerative cerebellar disorders.
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60
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Cook AA, Fields E, Watt AJ. Losing the Beat: Contribution of Purkinje Cell Firing Dysfunction to Disease, and Its Reversal. Neuroscience 2020; 462:247-261. [PMID: 32554108 DOI: 10.1016/j.neuroscience.2020.06.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023]
Abstract
The cerebellum is a brain structure that is highly interconnected with other brain regions. There are many contributing factors to cerebellar-related brain disease, such as altered afferent input, local connectivity, and/or cerebellar output. Purkinje cells (PC) are the principle cells of the cerebellar cortex, and fire intrinsically; that is, they fire spontaneous action potentials at high frequencies. This review paper focuses on PC intrinsic firing activity, which is altered in multiple neurological diseases, including ataxia, Huntington Disease (HD) and autism spectrum disorder (ASD). Notably, there are several cases where interventions that restore or rescue PC intrinsic activity also improve impaired behavior in these mouse models of disease. These findings suggest that rescuing PC firing deficits themselves may be sufficient to improve impairment in cerebellar-related behavior in disease. We propose that restoring PC intrinsic firing represents a good target for drug development that might be of therapeutic use for several disorders.
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Affiliation(s)
- Anna A Cook
- Department of Biology, McGill University, Montreal, Canada
| | - Eviatar Fields
- Department of Biology, McGill University, Montreal, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, Canada.
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61
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Ohtsuki G, Shishikura M, Ozaki A. Synergistic excitability plasticity in cerebellar functioning. FEBS J 2020; 287:4557-4593. [PMID: 32367676 DOI: 10.1111/febs.15355] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/22/2020] [Accepted: 04/30/2020] [Indexed: 12/27/2022]
Abstract
The cerebellum, a universal processor for sensory acquisition and internal models, and its association with synaptic and nonsynaptic plasticity have been envisioned as the biological correlates of learning, perception, and even thought. Indeed, the cerebellum is no longer considered merely as the locus of motor coordination and its learning. Here, we introduce the mechanisms underlying the induction of multiple types of plasticity in cerebellar circuit and give an overview focusing on the plasticity of nonsynaptic intrinsic excitability. The discovery of long-term potentiation of synaptic responsiveness in hippocampal neurons led investigations into changes of their intrinsic excitability. This activity-dependent potentiation of neuronal excitability is distinct from that of synaptic efficacy. Systematic examination of excitability plasticity has indicated that the modulation of various types of Ca2+ - and voltage-dependent K+ channels underlies the phenomenon, which is also triggered by immune activity. Intrinsic plasticity is expressed specifically on dendrites and modifies the integrative processing and filtering effect. In Purkinje cells, modulation of the discordance of synaptic current on soma and dendrite suggested a novel type of cellular learning mechanism. This property enables a plausible synergy between synaptic efficacy and intrinsic excitability, by amplifying electrical conductivity and influencing the polarity of bidirectional synaptic plasticity. Furthermore, the induction of intrinsic plasticity in the cerebellum correlates with motor performance and cognitive processes, through functional connections from the cerebellar nuclei to neocortex and associated regions: for example, thalamus and midbrain. Taken together, recent advances in neuroscience have begun to shed light on the complex functioning of nonsynaptic excitability and the synergy.
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Affiliation(s)
- Gen Ohtsuki
- The Hakubi Center for Advanced Research, Kyoto University, Japan.,Department of Biophysics, Kyoto University Graduate School of Science, Japan.,Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Japan
| | - Mari Shishikura
- Department of Biophysics, Kyoto University Graduate School of Science, Japan
| | - Akitoshi Ozaki
- Department of Biophysics, Kyoto University Graduate School of Science, Japan
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62
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Frasca A, Spiombi E, Palmieri M, Albizzati E, Valente MM, Bergo A, Leva B, Kilstrup‐Nielsen C, Bianchi F, Di Carlo V, Di Cunto F, Landsberger N. MECP2 mutations affect ciliogenesis: a novel perspective for Rett syndrome and related disorders. EMBO Mol Med 2020; 12:e10270. [PMID: 32383329 PMCID: PMC7278541 DOI: 10.15252/emmm.201910270] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/19/2020] [Accepted: 03/26/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations in MECP2 cause several neurological disorders of which Rett syndrome (RTT) represents the best-defined condition. Although mainly working as a transcriptional repressor, MeCP2 is a multifunctional protein revealing several activities, the involvement of which in RTT remains obscure. Besides being mainly localized in the nucleus, MeCP2 associates with the centrosome, an organelle from which primary cilia originate. Primary cilia function as "sensory antennae" protruding from most cells, and a link between primary cilia and mental illness has recently been reported. We herein demonstrate that MeCP2 deficiency affects ciliogenesis in cultured cells, including neurons and RTT fibroblasts, and in the mouse brain. Consequently, the cilium-related Sonic Hedgehog pathway, which is essential for brain development and functioning, is impaired. Microtubule instability participates in these phenotypes that can be rescued by HDAC6 inhibition together with the recovery of RTT-related neuronal defects. Our data indicate defects of primary cilium as a novel pathogenic mechanism that by contributing to the clinical features of RTT might impact on proper cerebellum/brain development and functioning, thus providing a novel therapeutic target.
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Affiliation(s)
- Angelisa Frasca
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Eleonora Spiombi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Michela Palmieri
- Neuroscience DivisionIRCCS San Raffaele Scientific InstituteMilanItaly
| | - Elena Albizzati
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Maria Maddalena Valente
- Department of Biotechnology and Life SciencesCentre of NeuroscienceUniversity of InsubriaBusto ArsizioItaly
| | - Anna Bergo
- Department of Biotechnology and Life SciencesCentre of NeuroscienceUniversity of InsubriaBusto ArsizioItaly
| | - Barbara Leva
- Department of Biotechnology and Life SciencesCentre of NeuroscienceUniversity of InsubriaBusto ArsizioItaly
| | - Charlotte Kilstrup‐Nielsen
- Department of Biotechnology and Life SciencesCentre of NeuroscienceUniversity of InsubriaBusto ArsizioItaly
| | | | - Valerio Di Carlo
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Ferdinando Di Cunto
- Neuroscience Institute Cavalieri OttolenghiOrbassanoItaly
- Department of NeuroscienceUniversity of TorinoTorinoItaly
| | - Nicoletta Landsberger
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
- Neuroscience DivisionIRCCS San Raffaele Scientific InstituteMilanItaly
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63
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Chao OY, Marron Fernandez de Velasco E, Pathak SS, Maitra S, Zhang H, Duvick L, Wickman K, Orr HT, Hirai H, Yang YM. Targeting inhibitory cerebellar circuitry to alleviate behavioral deficits in a mouse model for studying idiopathic autism. Neuropsychopharmacology 2020; 45:1159-1170. [PMID: 32179875 PMCID: PMC7234983 DOI: 10.1038/s41386-020-0656-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/11/2020] [Accepted: 03/03/2020] [Indexed: 11/30/2022]
Abstract
Autism spectrum disorder (ASD) encompasses wide-ranging neuropsychiatric symptoms with unclear etiology. Although the cerebellum is a key region implicated in ASD, it remains elusive how the cerebellar circuitry is altered and whether the cerebellum can serve as a therapeutic target to rectify the phenotype of idiopathic ASD with polygenic abnormalities. Using a syndromic ASD model, e.g., Black and Tan BRachyury T+Itpr3tf/J (BTBR) mice, we revealed that increased excitability of presynaptic interneurons (INs) and decreased intrinsic excitability of postsynaptic Purkinje neurons (PNs) resulted in low PN firing rates in the cerebellum. Knowing that downregulation of Kv1.2 potassium channel in the IN nerve terminals likely augmented their excitability and GABA release, we applied a positive Kv1.2 modulator to mitigate the presynaptic over-inhibition and social impairment of BTBR mice. Selective restoration of the PN activity by a new chemogenetic approach alleviated core ASD-like behaviors of the BTBR strain. These findings highlight complex mechanisms converging onto the cerebellar dysfunction in the phenotypic model and provide effective strategies for potential therapies of ASD.
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Affiliation(s)
- Owen Y Chao
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA
| | | | - Salil Saurav Pathak
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA
| | - Swati Maitra
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA
| | - Hao Zhang
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA
| | - Lisa Duvick
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Kevin Wickman
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Harry T Orr
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Yi-Mei Yang
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA.
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA.
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64
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Lieberman OJ, Cartocci V, Pigulevskiy I, Molinari M, Carbonell J, Broseta MB, Post MR, Sulzer D, Borgkvist A, Santini E. mTOR Suppresses Macroautophagy During Striatal Postnatal Development and Is Hyperactive in Mouse Models of Autism Spectrum Disorders. Front Cell Neurosci 2020; 14:70. [PMID: 32296308 PMCID: PMC7136750 DOI: 10.3389/fncel.2020.00070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 03/11/2020] [Indexed: 01/06/2023] Open
Abstract
Macroautophagy (hereafter referred to as autophagy) plays a critical role in neuronal function related to development and degeneration. Here, we investigated whether autophagy is developmentally regulated in the striatum, a brain region implicated in neurodevelopmental disease. We demonstrate that autophagic flux is suppressed during striatal postnatal development, reaching adult levels around postnatal day 28 (P28). We also find that mTOR signaling, a key regulator of autophagy, increases during the same developmental period. We further show that mTOR signaling is responsible for suppressing autophagy, via regulation of Beclin-1 and VPS34 activity. Finally, we discover that autophagy is downregulated during late striatal postnatal development (P28) in mice with in utero exposure to valproic acid (VPA), an established mouse model of autism spectrum disorder (ASD). VPA-exposed mice also display deficits in striatal neurotransmission and social behavior. Correction of hyperactive mTOR signaling in VPA-exposed mice restores social behavior. These results demonstrate that neurons coopt metabolic signaling cascades to developmentally regulate autophagy and provide additional evidence that mTOR-dependent signaling pathways represent pathogenic signaling cascades in ASD mouse models that are active during specific postnatal windows.
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Affiliation(s)
- Ori J. Lieberman
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | | | - Irena Pigulevskiy
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - Maya Molinari
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Josep Carbonell
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | - Michael R. Post
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - David Sulzer
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - Anders Borgkvist
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Emanuela Santini
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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65
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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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66
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Afshar Saber W, Sahin M. Recent advances in human stem cell-based modeling of Tuberous Sclerosis Complex. Mol Autism 2020; 11:16. [PMID: 32075691 PMCID: PMC7031912 DOI: 10.1186/s13229-020-0320-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by epilepsy, intellectual disability, and benign tumors of the brain, heart, skin, and kidney. Animal models have contributed to our understanding of normal and abnormal human brain development, but the construction of models that accurately recapitulate a human pathology remains challenging. Recent advances in stem cell biology with the derivation of human-induced pluripotent stem cells (hiPSCs) from somatic cells from patients have opened new avenues to the study of TSC. This approach combined with gene-editing tools such as CRISPR/Cas9 offers the advantage of preserving patient-specific genetic background and the ability to generate isogenic controls by correcting a specific mutation. The patient cell line and the isogenic control can be differentiated into the cell type of interest to model various aspects of TSC. In this review, we discuss the remarkable capacity of these cells to be used as a model for TSC in two- and three-dimensional cultures, the potential variability in iPSC models, and highlight differences between findings reported to date.
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Affiliation(s)
- Wardiya Afshar Saber
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Mustafa Sahin
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA.
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67
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Lieberman OJ, Cartocci V, Pigulevskiy I, Molinari M, Carbonell J, Broseta MB, Post MR, Sulzer D, Borgkvist A, Santini E. mTOR Suppresses Macroautophagy During Striatal Postnatal Development and Is Hyperactive in Mouse Models of Autism Spectrum Disorders. Front Cell Neurosci 2020; 14:70. [PMID: 32296308 DOI: 10.3389/fncel.2020.00070/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 03/11/2020] [Indexed: 05/20/2023] Open
Abstract
Macroautophagy (hereafter referred to as autophagy) plays a critical role in neuronal function related to development and degeneration. Here, we investigated whether autophagy is developmentally regulated in the striatum, a brain region implicated in neurodevelopmental disease. We demonstrate that autophagic flux is suppressed during striatal postnatal development, reaching adult levels around postnatal day 28 (P28). We also find that mTOR signaling, a key regulator of autophagy, increases during the same developmental period. We further show that mTOR signaling is responsible for suppressing autophagy, via regulation of Beclin-1 and VPS34 activity. Finally, we discover that autophagy is downregulated during late striatal postnatal development (P28) in mice with in utero exposure to valproic acid (VPA), an established mouse model of autism spectrum disorder (ASD). VPA-exposed mice also display deficits in striatal neurotransmission and social behavior. Correction of hyperactive mTOR signaling in VPA-exposed mice restores social behavior. These results demonstrate that neurons coopt metabolic signaling cascades to developmentally regulate autophagy and provide additional evidence that mTOR-dependent signaling pathways represent pathogenic signaling cascades in ASD mouse models that are active during specific postnatal windows.
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Affiliation(s)
- Ori J Lieberman
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | | | - Irena Pigulevskiy
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - Maya Molinari
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Josep Carbonell
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | - Michael R Post
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - David Sulzer
- Division of Molecular Therapeutics, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - Anders Borgkvist
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Emanuela Santini
- Division of Movement Disorders, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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68
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69
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Behavioral predictors of autism recurrence are genetically independent and influence social reciprocity: evidence that polygenic ASD risk is mediated by separable elements of developmental liability. Transl Psychiatry 2019; 9:202. [PMID: 31439834 PMCID: PMC6706410 DOI: 10.1038/s41398-019-0545-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 06/24/2019] [Accepted: 07/17/2019] [Indexed: 01/12/2023] Open
Abstract
The preponderance of causal influence on total population attributable risk for autism is polygenic in nature, but it is not known how such liability engenders the development of the syndrome. In 348 epidemiologically ascertained toddler twins, we explored associations between autistic traits and three robust, highly heritable predictors of familial autism recurrence: variation in attention, motor coordination, and parental autistic trait burden. We observed that these predictors-despite collectively accounting for over one third of variance in clinical recurrence-are genetically independent in early childhood, and jointly account for a comparable share of inherited influence on early reciprocal social behavior in the general population. Thus, combinations of what are otherwise discrete, inherited behavioral liabilities-some not specific to autism-appear to jointly mediate common genetic risk for autism. Linking genetic variants and neural signatures to these independent traits prior to the onset of the development of autism will enhance understanding of mechanisms of causation in familial autistic syndromes. Moreover, ongoing biomarker discovery efforts will benefit from controlling for the effects of these common liabilities, which aggregate in individuals with autism but are also continuously distributed in "controls". Finally, early inherited liabilities that participate in the early ontogeny of autistic syndromes represent parsimonious intervention targets for polygenic forms of the condition, and represent candidate trans-diagnostic endophenotypes of potential relevance to a diversity of neuropsychiatric syndromes.
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70
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Yang Z, Joyner AL. YAP1 is involved in replenishment of granule cell precursors following injury to the neonatal cerebellum. Dev Biol 2019; 455:458-472. [PMID: 31376393 DOI: 10.1016/j.ydbio.2019.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/30/2019] [Accepted: 07/30/2019] [Indexed: 01/08/2023]
Abstract
The cerebellum undergoes major rapid growth during the third trimester and early neonatal stage in humans, making it vulnerable to injuries in pre-term babies. Experiments in mice have revealed a remarkable ability of the neonatal cerebellum to recover from injuries around birth. In particular, recovery following irradiation-induced ablation of granule cell precursors (GCPs) involves adaptive reprogramming of Nestin-expressing glial progenitors (NEPs). Sonic hedgehog signaling is required for the initial step in NEP reprogramming; however, the full spectrum of developmental signaling pathways that promote NEP-driven regeneration is not known. Since the growth regulatory Hippo pathway has been implicated in the repair of several tissue types, we tested whether Hippo signaling is involved in regeneration of the cerebellum. Using mouse models, we found that the Hippo pathway transcriptional co-activator YAP1 (Yes-associated protein 1) but not TAZ (transcriptional coactivator with PDZ binding motif, or WWTR1) is required in NEPs for full recovery of cerebellar growth following irradiation one day after birth. Although Yap1 plays only a minor role during normal development in differentiation of NEPs or GCPs, the size of the cerebellum, and in particular the internal granule cell layer produced by GCPs, is significantly reduced in Yap1 mutants after irradiation, and the organization of Purkinje cells and Bergmann glial fibers is disrupted. The initial proliferative response of Yap1 mutant NEPs to irradiation is normal and the cells migrate to the GCP niche, but subsequently there is increased cell death of GCPs and altered migration of granule cells, possibly due to defects in Bergmann glia. Moreover, loss of Taz along with Yap1 in NEPs does not abrogate regeneration or alter development of the cerebellum. Our study provides new insights into the molecular signaling underlying postnatal cerebellar development and regeneration.
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Affiliation(s)
- Zhaohui Yang
- Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, 10065, United States; Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, United States
| | - Alexandra L Joyner
- Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, 10065, United States; Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, United States.
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71
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Blair JD, Bateup HS. New frontiers in modeling tuberous sclerosis with human stem cell-derived neurons and brain organoids. Dev Dyn 2019; 249:46-55. [PMID: 31070828 DOI: 10.1002/dvdy.60] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/01/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022] Open
Abstract
Recent advances in human stem cell and genome engineering have enabled the generation of genetically defined human cellular models for brain disorders. These models can be established from a patient's own cells and can be genetically engineered to generate isogenic, controlled systems for mechanistic studies. Given the challenges of obtaining and working with primary human brain tissue, these models fill a critical gap in our understanding of normal and abnormal human brain development and provide an important complement to animal models. Recently, there has been major progress in modeling the neuropathophysiology of the canonical "mTORopathy" tuberous sclerosis complex (TSC) with such approaches. Studies using two- and three-dimensional cultures of human neurons and glia have provided new insights into how mutations in the TSC1 and TSC2 genes impact human neural development and function. Here we discuss recent progress in human stem cell-based modeling of TSC and highlight challenges and opportunities for further efforts in this area.
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Affiliation(s)
- John D Blair
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, California.,Helen Wills Neuroscience Institute, University of California, Berkeley, California.,Chan Zuckerberg Biohub, San Francisco, California
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72
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Salussolia CL, Klonowska K, Kwiatkowski DJ, Sahin M. Genetic Etiologies, Diagnosis, and Treatment of Tuberous Sclerosis Complex. Annu Rev Genomics Hum Genet 2019; 20:217-240. [PMID: 31018109 DOI: 10.1146/annurev-genom-083118-015354] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects multiple organ systems due to an inactivating variant in either TSC1 or TSC2, resulting in the hyperactivation of the mechanistic target of rapamycin (mTOR) pathway. Dysregulated mTOR signaling results in increased cell growth and proliferation. Clinically, TSC patients exhibit great phenotypic variability, but the neurologic and neuropsychiatric manifestations of the disease have the greatest morbidity and mortality. TSC-associated epilepsy occurs in nearly all patients and is often difficult to treat because it is refractory to multiple antiseizure medications. The advent of mTOR inhibitors offers great promise in the treatment of TSC-associated epilepsy and other neurodevelopmental manifestations of the disease; however, the optimal timing of therapeutic intervention is not yet fully understood.
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Affiliation(s)
- Catherine L Salussolia
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Katarzyna Klonowska
- Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - David J Kwiatkowski
- Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA;
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