101
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Julian LM, Stanford WL. Organelle Cooperation in Stem Cell Fate: Lysosomes as Emerging Regulators of Cell Identity. Front Cell Dev Biol 2020; 8:591. [PMID: 32733892 PMCID: PMC7358313 DOI: 10.3389/fcell.2020.00591] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/17/2020] [Indexed: 12/26/2022] Open
Abstract
Regulation of stem cell fate is best understood at the level of gene and protein regulatory networks, though it is now clear that multiple cellular organelles also have critical impacts. A growing appreciation for the functional interconnectedness of organelles suggests that an orchestration of integrated biological networks functions to drive stem cell fate decisions and regulate metabolism. Metabolic signaling itself has emerged as an integral regulator of cell fate including the determination of identity, activation state, survival, and differentiation potential of many developmental, adult, disease, and cancer-associated stem cell populations and their progeny. As the primary adenosine triphosphate-generating organelles, mitochondria are well-known regulators of stem cell fate decisions, yet it is now becoming apparent that additional organelles such as the lysosome are important players in mediating these dynamic decisions. In this review, we will focus on the emerging role of organelles, in particular lysosomes, in the reprogramming of both metabolic networks and stem cell fate decisions, especially those that impact the determination of cell identity. We will discuss the inter-organelle interactions, cell signaling pathways, and transcriptional regulatory mechanisms with which lysosomes engage and how these activities impact metabolic signaling. We will further review recent data that position lysosomes as critical regulators of cell identity determination programs and discuss the known or putative biological mechanisms. Finally, we will briefly highlight the potential impact of elucidating mechanisms by which lysosomes regulate stem cell identity on our understanding of disease pathogenesis, as well as the development of refined regenerative medicine, biomarker, and therapeutic strategies.
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Affiliation(s)
- Lisa M. Julian
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - William L. Stanford
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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102
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Gopal S, Rodrigues AL, Dordick JS. Exploiting CRISPR Cas9 in Three-Dimensional Stem Cell Cultures to Model Disease. Front Bioeng Biotechnol 2020; 8:692. [PMID: 32671050 PMCID: PMC7326781 DOI: 10.3389/fbioe.2020.00692] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 06/03/2020] [Indexed: 12/14/2022] Open
Abstract
Three-dimensional (3D) cell culture methods have been widely used on a range of cell types, including stem cells to modulate precisely the cellular biophysical and biochemical microenvironment and control various cell signaling cues. As a result, more in vivo-like microenvironments are recapitulated, particularly through the formation of multicellular spheroids and organoids, which may yield more valid mechanisms of disease. Recently, genome-engineering tools such as CRISPR Cas9 have expanded the repertoire of techniques to control gene expression, which complements external signaling cues with intracellular control elements. As a result, the combination of CRISPR Cas9 and 3D cell culture methods enhance our understanding of the molecular mechanisms underpinning several disease phenotypes and may lead to developing new therapeutics that may advance more quickly and effectively into clinical candidates. In addition, using CRISPR Cas9 tools to rescue genes brings us one step closer to its use as a gene therapy tool for various degenerative diseases. Herein, we provide an overview of bridging of CRISPR Cas9 genome editing with 3D spheroid and organoid cell culture to better understand disease progression in both patient and non-patient derived cells, and we address potential remaining gaps that must be overcome to gain widespread use.
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Affiliation(s)
- Sneha Gopal
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - André Lopes Rodrigues
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Jonathan S. Dordick
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States
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103
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Zhang DY, Song H, Ming GL. Modeling neurological disorders using brain organoids. Semin Cell Dev Biol 2020; 111:4-14. [PMID: 32561297 DOI: 10.1016/j.semcdb.2020.05.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/08/2020] [Accepted: 05/27/2020] [Indexed: 12/18/2022]
Abstract
Neurological disorders are challenging to study given the complexity and species-specific features of the organ system. Brain organoids are three dimensional structured aggregates of neural tissue that are generated by self-organization and differentiation from pluripotent stem cells under optimized culture conditions. These brain organoids exhibit similar features of structural organization and cell type diversity as the developing human brain, creating opportunities to recapitulate disease phenotypes that are not otherwise accessible. Here we review the initial attempt in the field to apply brain organoid models for the study of many different types of human neurological disorders across a wide range of etiologies and pathophysiologies. Forthcoming advancements in both brain organoid technology as well as analytical methods have significant potentials to advance the understanding of neurological disorders and to uncover opportunities for meaningful therapeutic intervention.
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Affiliation(s)
- Daniel Y Zhang
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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104
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Neurodevelopmental Disorders: From Genetics to Functional Pathways. Trends Neurosci 2020; 43:608-621. [PMID: 32507511 DOI: 10.1016/j.tins.2020.05.004] [Citation(s) in RCA: 233] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/27/2020] [Accepted: 05/18/2020] [Indexed: 12/21/2022]
Abstract
Neurodevelopmental disorders (NDDs) are a class of disorders affecting brain development and function and are characterized by wide genetic and clinical variability. In this review, we discuss the multiple factors that influence the clinical presentation of NDDs, with particular attention to gene vulnerability, mutational load, and the two-hit model. Despite the complex architecture of mutational events associated with NDDs, the various proteins involved appear to converge on common pathways, such as synaptic plasticity/function, chromatin remodelers and the mammalian target of rapamycin (mTOR) pathway. A thorough understanding of the mechanisms behind these pathways will hopefully lead to the identification of candidates that could be targeted for treatment approaches.
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105
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Increased Tau Expression Correlates with Neuronal Maturation in the Developing Human Cerebral Cortex. eNeuro 2020; 7:ENEURO.0058-20.2020. [PMID: 32393582 PMCID: PMC7262004 DOI: 10.1523/eneuro.0058-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/02/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023] Open
Abstract
Although best known for its role in Alzheimer's disease (AD), tau is expressed throughout brain development, although it remains unclear when and which cell types this expression occurs and how it affects disease states in both fetal and neonatal periods. We thus sought to map tau mRNA and protein expression in the developing human brain at the cellular level using a combination of existing single-cell RNA sequencing (sc-RNAseq) data, RNA in situ hybridization (RNAscope), and immunohistochemistry (IHC). Using sc-RNAseq, we found that tau mRNA expression begins in radial glia but increases dramatically as migrating neuronal precursors mature. Specifically, TBR1 + maturing neurons and SYN + mature neurons showed significantly higher mRNA expression than GFAP +/NES + radial glia or TBR2 + intermediate progenitors. By RNAscope, we found low levels of tau mRNA in subventricular zone (SVZ) radial glia and deep white matter intermediate progenitors, with an increase in more superficially located maturing and mature neurons. By total-tau IHC, the germinal matrix and SVZ showed little protein expression, although both RNAscope and sc-RNAseq showed mRNA, and Western blotting revealed significantly less protein in those areas compared with more mature regions. Induced pluripotent stem cell (iPSC)-derived cortical organoids showed a similar tau expression pattern by sc-RNAseq and RNAscope. Our results indicate that tau increases with neuronal maturation in both the developing fetal brain and iPSC-derived organoids and forms a basis for future research on regulatory mechanisms triggering the onset of tau gene transcription and translation, which may represent potential therapeutic targets for neurodegenerative tauopathies and neurodevelopmental disorders.
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106
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Dang LT, Glanowska KM, Iffland Ii PH, Barnes AE, Baybis M, Liu Y, Patino G, Vaid S, Streicher AM, Parker WE, Kim S, Moon UY, Henry FE, Murphy GG, Sutton M, Parent JM, Crino PB. Multimodal Analysis of STRADA Function in Brain Development. Front Cell Neurosci 2020; 14:122. [PMID: 32457579 PMCID: PMC7227375 DOI: 10.3389/fncel.2020.00122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/14/2020] [Indexed: 12/22/2022] Open
Abstract
mTORopathies are a heterogeneous group of neurological disorders characterized by malformations of cortical development (MCD), enhanced cellular mechanistic target of rapamycin (mTOR) signaling, and epilepsy that results from mutations in mTOR pathway regulatory genes. Homozygous mutations (del exon 9–13) in the pseudokinase STE20-related kinase adaptor alpha (STRAD-α; STRADA), an mTOR modulator, are associated with Pretzel Syndrome (PS), a neurodevelopmental disorder within the Old Order Mennonite Community characterized by megalencephaly, intellectual disability, and intractable epilepsy. To study the cellular mechanisms of STRADA loss, we generated CRISPR-edited Strada mouse N2a cells, a germline mouse Strada knockout (KO−/−) strain, and induced pluripotent stem cell (iPSC)-derived neurons from PS individuals harboring the STRADA founder mutation. Strada KO in vitro leads to enhanced mTOR signaling and iPSC-derived neurons from PS individuals exhibit enhanced cell size and mTOR signaling activation, as well as subtle alterations in electrical firing properties e.g., increased input resistance, a more depolarized resting membrane potential, and decreased threshold for action potential (AP) generation. Strada−/− mice exhibit high rates of perinatal mortality and out of more than 100 litters yielding both WT and heterozygous pups, only eight Strada−/− animals survived past P5. Strada−/− mice are hypotonic and tremulous. Histopathological examination (n = 5 mice) revealed normal gross brain organization and lamination but all had ventriculomegaly. Ectopic neurons were seen in all five Strada−/− brains within the subcortical white matter mirroring what is observed in human PS brain tissue. These distinct experimental platforms demonstrate that STRADA modulates mTOR signaling and is a key regulator of cell size, neuronal excitability, and cortical lamination.
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Affiliation(s)
- Louis T Dang
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, United States
| | - Katarzyna M Glanowska
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States
| | - Philip H Iffland Ii
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Allan E Barnes
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marianna Baybis
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yu Liu
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States
| | - Gustavo Patino
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States
| | - Shivanshi Vaid
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, United States
| | | | - Whitney E Parker
- Department of Neurosurgery, Weill-Cornell Medical Center, New York, NY, United States
| | - Seonhee Kim
- Louis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Uk Yeol Moon
- Louis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Frederick E Henry
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Geoffrey G Murphy
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Michael Sutton
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Jack M Parent
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Neurology Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, United States
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
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107
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Kruth KA, Grisolano TM, Ahern CA, Williams AJ. SCN2A channelopathies in the autism spectrum of neuropsychiatric disorders: a role for pluripotent stem cells? Mol Autism 2020; 11:23. [PMID: 32264956 PMCID: PMC7140374 DOI: 10.1186/s13229-020-00330-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
Efforts to identify the causes of autism spectrum disorders have highlighted the importance of both genetics and environment, but the lack of human models for many of these disorders limits researchers’ attempts to understand the mechanisms of disease and to develop new treatments. Induced pluripotent stem cells offer the opportunity to study specific genetic and environmental risk factors, but the heterogeneity of donor genetics may obscure important findings. Diseases associated with unusually high rates of autism, such as SCN2A syndromes, provide an opportunity to study specific mutations with high effect sizes in a human genetic context and may reveal biological insights applicable to more common forms of autism. Loss-of-function mutations in the SCN2A gene, which encodes the voltage-gated sodium channel NaV1.2, are associated with autism rates up to 50%. Here, we review the findings from experimental models of SCN2A syndromes, including mouse and human cell studies, highlighting the potential role for patient-derived induced pluripotent stem cell technology to identify the molecular and cellular substrates of autism.
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Affiliation(s)
- Karina A Kruth
- Department of Psychiatry, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2326 PBDB, Iowa City, IA, 52242, USA
| | - Tierney M Grisolano
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2312 PBDB, Iowa City, IA, 52242, USA
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2312 PBDB, Iowa City, IA, 52242, USA
| | - Aislinn J Williams
- Department of Psychiatry, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2326 PBDB, Iowa City, IA, 52242, USA.
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108
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An update on the central nervous system manifestations of tuberous sclerosis complex. Acta Neuropathol 2020; 139:613-624. [PMID: 30976976 DOI: 10.1007/s00401-019-02003-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 12/17/2022]
Abstract
The autosomal dominant disorder tuberous sclerosis complex (TSC) is characterized by an array of manifestations both within and outside of the central nervous system (CNS), including hamartomas and other malformations. TSC is caused by mutations in the TSC1 or TSC2 gene resulting in activation of the mechanistic target of rapamycin (mTOR) signaling pathway. Study of TSC has shed light on the critical role of the mTOR pathway in neurodevelopment. This update reviews the genetic basis of TSC, its cardinal phenotypic CNS features, and recent developments in the field of TSC and other mTOR-altered disorders.
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109
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Khakipoor S, Crouch EE, Mayer S. Human organoids to model the developing human neocortex in health and disease. Brain Res 2020; 1742:146803. [PMID: 32240655 DOI: 10.1016/j.brainres.2020.146803] [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: 09/04/2019] [Revised: 01/28/2020] [Accepted: 03/24/2020] [Indexed: 02/06/2023]
Abstract
Rodent models have catalyzed major discoveries in the neocortex, a brain region unique to mammals. However, since the neocortex has expanded considerably in primates, employing rodent models has limitations. Human fetal brain tissue is a scarce resource with limitations for experimental manipulations. In order to create an experimentally tractable representation of human brain development, a number of labs have recently created in vitro models of the developing human brain. These models, generated using human embryonic stem cells or induced pluripotent stem cells, are called "organoids". Organoids have successfully and rapidly uncovered new mechanisms of human brain development in health and disease. In the future, we envision that this strategy will enable faster and more efficient translation of basic neuroscience findings to therapeutic applications. In this review, we discuss the generation of the first human cerebral organoids, progress since their debut, and challenges to be overcome in the future.
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Affiliation(s)
- Shokoufeh Khakipoor
- Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Elizabeth E Crouch
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Simone Mayer
- Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany.
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110
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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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111
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Mostajo-Radji MA, Schmitz MT, Montoya ST, Pollen AA. Reverse engineering human brain evolution using organoid models. Brain Res 2020; 1729:146582. [PMID: 31809699 PMCID: PMC7058376 DOI: 10.1016/j.brainres.2019.146582] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/06/2023]
Abstract
Primate brains vary dramatically in size and organization, but the genetic and developmental basis for these differences has been difficult to study due to lack of experimental models. Pluripotent stem cells and brain organoids provide a potential opportunity for comparative and functional studies of evolutionary differences, particularly during the early stages of neurogenesis. However, many challenges remain, including isolating stem cell lines from additional great ape individuals and species to capture the breadth of ape genetic diversity, improving the reproducibility of organoid models to study evolved differences in cell composition and combining multiple brain regions to capture connectivity relationships. Here, we describe strategies for identifying evolved developmental differences between humans and non-human primates and for isolating the underlying cellular and genetic mechanisms using comparative analyses, chimeric organoid culture, and genome engineering. In particular, we focus on how organoid models could ultimately be applied beyond studies of progenitor cell evolution to decode the origin of recent changes in cellular organization, connectivity patterns, myelination, synaptic development, and physiology that have been implicated in human cognition.
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Affiliation(s)
- Mohammed A Mostajo-Radji
- Department of Neurology, University of California San Francisco, San Francisco, CA 94143, USA; The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA
| | - Matthew T Schmitz
- Department of Neurology, University of California San Francisco, San Francisco, CA 94143, USA; The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA
| | - Sebastian Torres Montoya
- Health Co-creation Laboratory, Medellin General Hospital, Medellin, Antioquia, Colombia; Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Alex A Pollen
- Department of Neurology, University of California San Francisco, San Francisco, CA 94143, USA; The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA.
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112
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Wei J, Leung K, Truillet C, Ruggero D, Wells JA, Evans MJ. Profiling the Surfaceome Identifies Therapeutic Targets for Cells with Hyperactive mTORC1 Signaling. Mol Cell Proteomics 2020; 19:294-307. [PMID: 31792071 PMCID: PMC7000124 DOI: 10.1074/mcp.ra119.001785] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/04/2019] [Indexed: 11/06/2022] Open
Abstract
Aberrantly high mTORC1 signaling is a known driver of many cancers and human disorders, yet pharmacological inhibition of mTORC1 rarely confers durable clinical responses. To explore alternative therapeutic strategies, herein we conducted a proteomics survey to identify cell surface proteins upregulated by mTORC1. A comparison of the surfaceome from Tsc1-/-versus Tsc1+/+ mouse embryonic fibroblasts revealed 59 proteins predicted to be significantly overexpressed in Tsc1-/- cells. Further validation of the data in multiple mouse and human cell lines showed that mTORC1 signaling most dramatically induced the expression of the proteases neprilysin (NEP/CD10) and aminopeptidase N (APN/CD13). Functional studies showed that constitutive mTORC1 signaling sensitized cells to genetic ablation of NEP and APN, as well as the biochemical inhibition of APN. In summary, these data show that mTORC1 signaling plays a significant role in the constitution of the surfaceome, which in turn may present novel therapeutic strategies.
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Affiliation(s)
- Junnian Wei
- Department of Radiology and Biomedical Imaging, University of California San Francisco 505 Parnassus Ave, San Francisco California 94143
| | - Kevin Leung
- Department of Pharmaceutical Chemistry, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143
| | - Charles Truillet
- Imagerie Moleculaire In Vivo, INSERM, CEA, Univ. Paris Sud, CNRS, Universite Paris Saclay, CEA-Service Hospitalier Frederic Joliot, Orsay France, 94100
| | - Davide Ruggero
- Department of Urology, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143
| | - James A Wells
- Department of Pharmaceutical Chemistry, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143.
| | - Michael J Evans
- Department of Radiology and Biomedical Imaging, University of California San Francisco 505 Parnassus Ave, San Francisco California 94143; Department of Pharmaceutical Chemistry, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 505 Parnassus Ave, San Francisco California 94143.
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113
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Sterlini B, Fruscione F, Baldassari S, Benfenati F, Zara F, Corradi A. Progress of Induced Pluripotent Stem Cell Technologies to Understand Genetic Epilepsy. Int J Mol Sci 2020; 21:ijms21020482. [PMID: 31940887 PMCID: PMC7013950 DOI: 10.3390/ijms21020482] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 12/20/2022] Open
Abstract
The study of the pathomechanisms by which gene mutations lead to neurological diseases has benefit from several cellular and animal models. Recently, induced Pluripotent Stem Cell (iPSC) technologies have made possible the access to human neurons to study nervous system disease-related mechanisms, and are at the forefront of the research into neurological diseases. In this review, we will focalize upon genetic epilepsy, and summarize the most recent studies in which iPSC-based technologies were used to gain insight on the molecular bases of epilepsies. Moreover, we discuss the latest advancements in epilepsy cell modeling. At the two dimensional (2D) level, single-cell models of iPSC-derived neurons lead to a mature neuronal phenotype, and now allow a reliable investigation of synaptic transmission and plasticity. In addition, functional characterization of cerebral organoids enlightens neuronal network dynamics in a three-dimensional (3D) structure. Finally, we discuss the use of iPSCs as the cutting-edge technology for cell therapy in epilepsy.
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Affiliation(s)
- Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy;
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy;
| | - Floriana Fruscione
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy;
| | - Simona Baldassari
- Unità Operativa Complessa Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova Italy, Via G. Gaslini 5, 16147 Genoa, Italy;
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy;
- Istituto di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy;
- Unità Operativa Complessa Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova Italy, Via G. Gaslini 5, 16147 Genoa, Italy;
- Correspondence: (F.Z.); (A.C.)
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy;
- Istituto di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
- Correspondence: (F.Z.); (A.C.)
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114
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Martin P, Wagh V, Reis SA, Erdin S, Beauchamp RL, Shaikh G, Talkowski M, Thiele E, Sheridan SD, Haggarty SJ, Ramesh V. TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling. Mol Autism 2020; 11:2. [PMID: 31921404 PMCID: PMC6945400 DOI: 10.1186/s13229-019-0311-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/29/2019] [Indexed: 12/21/2022] Open
Abstract
Background Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability (ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors, but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. Methods Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a TSC patient with a heterozygous, germline, nonsense mutation in exon 15 of TSC1 and established an isogenic set of heterozygous (Het), null and corrected wildtype (Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental phenotypes, signaling and changes in gene expression by RNA-seq. Results Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs, consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced proliferation and altered neurite outgrowth in a genotype-dependent manner, which was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed differentially expressed genes that display a genotype-dependent linear response, i.e., genes upregulated/downregulated in Het were further increased/decreased in Null. In particular, genes linked to ASD, epilepsy, and ID were significantly upregulated or downregulated warranting further investigation. In TSC1-Het and Null NPCs, we also observed basal activation of ERK1/2, which was further activated upon rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in TSC1-deficient NPCs. Conclusion MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a role in neurodevelopmental defects. Our data showing upregulation of these signaling pathways by rapamycin support a strategy to combine a MEK or a MNK inhibitor with rapamycin that may be superior for TSC-associated CNS defects. Importantly, our generation of isogenic sets of NPCs from TSC patients provides a valuable platform for translatome and large-scale drug screening studies. Overall, our studies further support the notion that early developmental events such as NPC proliferation and initial process formation, such as neurite number and length that occur prior to neuronal differentiation, represent primary events in neurogenesis critical to disease pathogenesis of neurodevelopmental disorders such as ASD.
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Affiliation(s)
- Pauline Martin
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Vilas Wagh
- 2MERCK Research Laboratories, Boston, MA 02115 USA
| | - Surya A Reis
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Serkan Erdin
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Roberta L Beauchamp
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Ghalib Shaikh
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Michael Talkowski
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Elizabeth Thiele
- 3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Steven D Sheridan
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,4Center for Quantitative Health, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Stephen J Haggarty
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Vijaya Ramesh
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
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115
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Marton RM, Pașca SP. Organoid and Assembloid Technologies for Investigating Cellular Crosstalk in Human Brain Development and Disease. Trends Cell Biol 2019; 30:133-143. [PMID: 31879153 DOI: 10.1016/j.tcb.2019.11.004] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022]
Abstract
The biology of the human brain, and in particular the dynamic interactions between the numerous cell types and regions of the central nervous system, has been difficult to study due to limited access to functional brain tissue. Technologies to derive brain organoids and assembloids from human pluripotent stem cells are increasingly utilized to model, in progressively complex preparations, the crosstalk between cell types in development and disease. Here, we review the use of these human cellular models to study cell-cell interactions among progenitors, neurons, astrocytes, oligodendrocytes, cancer cells, and non-central nervous system cell types, as well as efforts to study connectivity between brain regions following controlled assembly of organoids. Ultimately, the promise of these patient-derived preparations is to uncover previously inaccessible features of brain function that emerge from complex cell-cell interactions and to improve our mechanistic understanding of neuropsychiatric disorders.
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Affiliation(s)
- Rebecca M Marton
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Stanford Human Brain Organogenesis Program, Stanford University, Stanford, CA, USA
| | - Sergiu P Pașca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Stanford Human Brain Organogenesis Program, Stanford University, Stanford, CA, USA.
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116
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Andrews MG, Nowakowski TJ. Human brain development through the lens of cerebral organoid models. Brain Res 2019; 1725:146470. [PMID: 31542572 PMCID: PMC6887101 DOI: 10.1016/j.brainres.2019.146470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/21/2019] [Accepted: 09/18/2019] [Indexed: 01/01/2023]
Abstract
The brain is one of the most complex organs in the body, which emerges from a relatively simple set of basic 'building blocks' during early development according to complex cellular and molecular events orchestrated through a set of inherited instructions. Innovations in stem cell technologies have enabled modelling of neural cells using two- and three-dimensional cultures. In particular, cerebral ('brain') organoids have taken the center stage of brain development models that have the potential for providing meaningful insight into human neurodevelopmental and neurological disorders. We review the current understanding of cellular events during human brain organogenesis, and the events occurring during cerebral organoid differentiation. We highlight the strengths and weaknesses of this experimental model system. In particular, we explain evidence that organoids can mimic many aspects of early neural development, including neural induction, patterning, and broad neurogenesis and gliogenesis programs, offering the opportunity to study genetic regulation of these processes in a human context. Several shortcomings of the current culture methods limit the utility of cerebral organoids to spontaneously give rise to many important cell types, and to model higher order features of tissue organization. We suggest that future studies aim to improve these features in order to make them better models for the study of laminar organization, circuit formation and how disruptions of these processes relate to disease.
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Affiliation(s)
- Madeline G Andrews
- Department of Neurology, University of California, San Francisco, CA, USA; The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA.
| | - Tomasz J Nowakowski
- Department of Anatomy, University of California, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
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117
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Rocktäschel P, Sen A, Cader MZ. High glucose concentrations mask cellular phenotypes in a stem cell model of tuberous sclerosis complex. Epilepsy Behav 2019; 101:106581. [PMID: 31761686 PMCID: PMC6943812 DOI: 10.1016/j.yebeh.2019.106581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022]
Abstract
Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder caused by deletions in the TSC1 or TSC2 genes that is associated with epilepsy in up to 90% of patients. Seizures are suggested to start in benign brain tumors, cortical tubers, or in the perituberal tissue making these tubers an interesting target for further research into mechanisms underlying epileptogenesis in TSC. Animal models of TSC insufficiently capture the neurodevelopmental biology of cortical tubers, and hence, human stem cell-based in vitro models of TSC are being increasingly explored in attempts to recapitulate tuber development and epileptogenesis in TSC. However, in vitro culture conditions for stem cell-derived neurons do not necessarily mimic physiological conditions. For example, very high glucose concentrations of up to 25 mM are common in culture media formulations. As TSC is potentially caused by a disruption of the mechanistic target of rapamycin (mTOR) pathway, a main integrator of metabolic information and intracellular signaling, we aimed to examine the impact of different glucose concentrations in the culture media on cellular phenotypes implicated in tuber characteristics. Here, we present preliminary data from a pilot study exploring cortical neuronal differentiation on human embryonic stem cells (hES) harboring a TSC2 knockout mutation (TSC2-/-) and an isogenic control line (TSC2+/+). We show that the commonly used high glucose media profoundly mask cellular phenotypes in TSC2-/- cultures during neuronal differentiation. These phenotypes only become apparent when differentiating TSC2+/+ and TSC2-/- cultures in more physiologically relevant conditions of 5 mM glucose suggesting that the careful consideration of culture conditions is vital to ensuring biological relevance and translatability of stem cell models for neurological disorders such as TSC. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
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Affiliation(s)
- Paula Rocktäschel
- Oxford Epilepsy Research Group, NIHR Oxford Biomedical Research Centre, Nuffield Department of Clinical Neuroscience, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom of Great Britain and Northern Ireland.
| | - Arjune Sen
- Oxford Epilepsy Research Group, NIHR Oxford Biomedical Research Centre, Nuffield Department of Clinical Neuroscience, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom of Great Britain and Northern Ireland
| | - M Zameel Cader
- Oxford Epilepsy Research Group, NIHR Oxford Biomedical Research Centre, Nuffield Department of Clinical Neuroscience, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom of Great Britain and Northern Ireland; MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom of Great Britain and Northern Ireland.
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118
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Costamagna G, Andreoli L, Corti S, Faravelli I. iPSCs-Based Neural 3D Systems: A Multidimensional Approach for Disease Modeling and Drug Discovery. Cells 2019; 8:E1438. [PMID: 31739555 PMCID: PMC6912470 DOI: 10.3390/cells8111438] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/26/2019] [Accepted: 11/11/2019] [Indexed: 02/06/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs)-based two-dimensional (2D) protocols have offered invaluable insights into the pathophysiology of neurological diseases. However, these systems are unable to reproduce complex cytoarchitectural features, cell-cell and tissue-tissue interactions like their in vivo counterpart. Three-dimensional (3D)-based culture protocols, though in their infancy, have offered new insights into modeling human diseases. Human neural organoids try to recapitulate the cellular diversity of complex tissues and can be generated from iPSCs to model the pathophysiology of a wide spectrum of pathologies. The engraftment of iPSCs into mice models and the improvement of differentiation protocols towards 3D cultures has enabled the generation of more complex multicellular systems. Consequently, models of neuropsychiatric disorders, infectious diseases, brain cancer and cerebral hypoxic injury can now be investigated from new perspectives. In this review, we consider the advancements made in modeling neuropsychiatric and neurological diseases with iPSC-derived organoids and their potential use to develop new drugs.
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Affiliation(s)
| | | | | | - Irene Faravelli
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (G.C.); (L.A.); (S.C.)
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119
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Verheijen BM. Modeling Brain Somatic Mosaicism With Cerebral Organoids, Including a Note on Mutant Microglia. Front Mol Neurosci 2019; 12:277. [PMID: 31798412 PMCID: PMC6868038 DOI: 10.3389/fnmol.2019.00277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 10/31/2019] [Indexed: 01/01/2023] Open
Abstract
The brain is a genomic mosaic. Cell-to-cell genomic differences, which are the result of somatic mutations during development and aging, contribute to cellular diversity in the nervous system. This genomic diversity has important implications for nervous system development, function, and disease. Brain somatic mosaicism might contribute to individualized behavioral phenotypes and has been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, understanding the causes and consequences of somatic mosaicism in neural circuits is of great interest. Recent advances in 3D cell culture technology have provided new means to study human organ development and various human pathologies in vitro. Cerebral organoids ("mini-brains") are pluripotent stem cell-derived 3D culture systems that recapitulate, to some extent, the developmental processes and organization of the developing human brain. Here, I discuss the application of these neural organoids for modeling brain somatic mosaicism in a lab dish. Special emphasis is given to the potential role of microglial mutations in the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Bert M. Verheijen
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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120
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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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121
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Lybrand ZR, Goswami S, Hsieh J. Stem cells: A path towards improved epilepsy therapies. Neuropharmacology 2019; 168:107781. [PMID: 31539537 DOI: 10.1016/j.neuropharm.2019.107781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
Despite the immense growth of new anti-seizure drugs (ASDs), approximately one-third of epilepsy patients remain resistant to current treatment options. Advancements in whole genome sequencing technology continues to identify an increasing number of epilepsy-associated genes at a rate that is outpacing the development of in vivo animal models. Patient-derived induced pluripotent stem cells (iPSCs) show promise in providing a platform for modeling genetic epilepsies, high throughput drug screening, and personalized medicine. This is largely due to the ease of collecting donor cells for iPSC reprogramming, and their ability to be maintained in vitro, while preserving the patient's genetic background. In this review, we summarize the current state of iPSC research in epilepsy and closely related syndromes, discuss the growing need for high-throughput drug screening (HTS), and review the use of stem cell technology for the purpose of autologous transplantation for epilepsy stem cell therapy. Although the use of iPSC technology, as it applies to ASD discovery, is in its infancy, we highlight the significant progress that has been made in phenotype and assay development to facilitate systematic HTS for personalized medicine. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Zane R Lybrand
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Sonal Goswami
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jenny Hsieh
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA.
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122
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Adams JW, Cugola FR, Muotri AR. Brain Organoids as Tools for Modeling Human Neurodevelopmental Disorders. Physiology (Bethesda) 2019; 34:365-375. [PMID: 31389776 PMCID: PMC6863377 DOI: 10.1152/physiol.00005.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022] Open
Abstract
Brain organoids recapitulate in vitro the specific stages of in vivo human brain development, thus offering an innovative tool by which to model human neurodevelopmental disease. We review here how brain organoids have been used to study neurodevelopmental disease and consider their potential for both technological advancement and therapeutic development.
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Affiliation(s)
- Jason W Adams
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
- Department of Neurosciences, School of Medicine, University of California San Diego, San Diego, California
| | - Fernanda R Cugola
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
| | - Alysson R Muotri
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
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123
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Niu W, Parent JM. Modeling genetic epilepsies in a dish. Dev Dyn 2019; 249:56-75. [DOI: 10.1002/dvdy.79] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 02/07/2023] Open
Affiliation(s)
- Wei Niu
- Department of Neurology and Neuroscience Graduate ProgramUniversity of Michigan Medical Center and VA Ann Arbor Healthcare System Ann Arbor Michigan
| | - Jack M. Parent
- Department of Neurology and Neuroscience Graduate ProgramUniversity of Michigan Medical Center and VA Ann Arbor Healthcare System Ann Arbor Michigan
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124
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Ye Z, McQuillan L, Poduri A, Green TE, Matsumoto N, Mefford HC, Scheffer IE, Berkovic SF, Hildebrand MS. Somatic mutation: The hidden genetics of brain malformations and focal epilepsies. Epilepsy Res 2019; 155:106161. [PMID: 31295639 DOI: 10.1016/j.eplepsyres.2019.106161] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 01/12/2023]
Abstract
Over the past decade there has been a substantial increase in genetic studies of brain malformations, fueled by the availability of improved technologies to study surgical tissue to address the hypothesis that focal lesions arise from focal, post-zygotic genetic disruptions. Traditional genetic studies of patients with malformations utilized leukocyte-derived DNA to search for germline variants, which are inherited or arise de novo in parental gametes. Recent studies have demonstrated somatic variants that arise post-zygotically also underlie brain malformations, and that somatic mutation explains a larger proportion of focal malformations than previously thought. We now know from studies of non-diseased individuals that somatic variation occurs routinely during cell division, including during early brain development when the rapid proliferation of neuronal precursor cells provides the ideal environment for somatic mutation to occur and somatic variants to accumulate. When confined to brain, pathogenic variants contribute to the "hidden genetics" of neurological diseases. With burgeoning novel high-throughput genetic technologies, somatic genetic variations are increasingly being recognized. Here we discuss accumulating evidence for the presence of somatic variants in normal brain tissue, review our current understanding of somatic variants in brain malformations associated with lesional epilepsy, and provide strategies to identify the potential contribution of somatic mutation to non-lesional epilepsies. We also discuss technologies that may improve detection of somatic variants in the future in these and other neurological conditions.
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Affiliation(s)
- Zimeng Ye
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Lara McQuillan
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Timothy E Green
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, WA, United States
| | - Ingrid E Scheffer
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Michael S Hildebrand
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
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125
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Shiri Z, Simorgh S, Naderi S, Baharvand H. Optogenetics in the Era of Cerebral Organoids. Trends Biotechnol 2019; 37:1282-1294. [PMID: 31227305 DOI: 10.1016/j.tibtech.2019.05.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/18/2019] [Accepted: 05/23/2019] [Indexed: 02/08/2023]
Abstract
The human brain has been deemed the most complex organ and has captivated neuroscientists for decades. Most studies of this organ have relied on reductionist model systems. Although all model systems are essentially wrong, cerebral organoids so far represent the closest recapitulation of human brain development and disease both in terms of cell diversity and organization. The optogenetic technique can be used in this context to study the functional neuroanatomy of the brain, to examine the neural circuits, and to determine the etiology of neurological disorders. In this opinion article, we suggest ways in which optogenetics can be combined with cerebral organoids to allow unprecedented precision and accuracy in studying normal and aberrant neurodevelopmental processes and, as well, neurodegenerative diseases.
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Affiliation(s)
- Zahra Shiri
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Susan Simorgh
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Somayeh Naderi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Hossein Baharvand
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, Tehran, Iran.
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126
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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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Karzbrun E, Reiner O. Brain Organoids-A Bottom-Up Approach for Studying Human Neurodevelopment. Bioengineering (Basel) 2019; 6:E9. [PMID: 30669275 PMCID: PMC6466401 DOI: 10.3390/bioengineering6010009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Brain organoids have recently emerged as a three-dimensional tissue culture platform to study the principles of neurodevelopment and morphogenesis. Importantly, brain organoids can be derived from human stem cells, and thus offer a model system for early human brain development and human specific disorders. However, there are still major differences between the in vitro systems and in vivo development. This is in part due to the challenge of engineering a suitable culture platform that will support proper development. In this review, we discuss the similarities and differences of human brain organoid systems in comparison to embryonic development. We then describe how organoids are used to model neurodevelopmental diseases. Finally, we describe challenges in organoid systems and how to approach these challenges using complementary bioengineering techniques.
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Affiliation(s)
- Eyal Karzbrun
- Kavli Institute for Theoretical Physics and Department of Physics, University of California, Santa Barbara, CA 93106, USA.
| | - Orly Reiner
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel.
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128
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Yoon SJ, Elahi LS, Pașca AM, Marton RM, Gordon A, Revah O, Miura Y, Walczak EM, Holdgate GM, Fan HC, Huguenard JR, Geschwind DH, Pașca SP. Reliability of human cortical organoid generation. Nat Methods 2019; 16:75-78. [PMID: 30573846 PMCID: PMC6677388 DOI: 10.1038/s41592-018-0255-0] [Citation(s) in RCA: 261] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 11/02/2018] [Indexed: 02/06/2023]
Abstract
The differentiation of pluripotent stem cells in three-dimensional cultures can recapitulate key aspects of brain development, but protocols are prone to variable results. Here we differentiated multiple human pluripotent stem cell lines for over 100 d using our previously developed approach to generate brain-region-specific organoids called cortical spheroids and, using several assays, found that spheroid generation was highly reliable and consistent. We anticipate the use of this approach for large-scale differentiation experiments and disease modeling.
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Affiliation(s)
- Se-Jin Yoon
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Lubayna S Elahi
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Anca M Pașca
- Department of Pediatrics, Division of Neonatology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rebecca M Marton
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Aaron Gordon
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Omer Revah
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Yuki Miura
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | - John R Huguenard
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel H Geschwind
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Sergiu P Pașca
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.
- Human Brain Organogenesis Program, Stanford University, Stanford, CA, USA.
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129
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Amin ND, Paşca SP. Building Models of Brain Disorders with Three-Dimensional Organoids. Neuron 2018; 100:389-405. [DOI: 10.1016/j.neuron.2018.10.007] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/01/2018] [Accepted: 10/04/2018] [Indexed: 12/11/2022]
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