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Talvio K, Minkeviciene R, Townsley KG, Achuta VS, Huckins LM, Corcoran P, Brennand KJ, Castrén ML. Reduced LYNX1 expression in transcriptome of human iPSC-derived neural progenitors modeling fragile X syndrome. Front Cell Dev Biol 2022; 10:1034679. [PMID: 36506088 PMCID: PMC9731341 DOI: 10.3389/fcell.2022.1034679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/04/2022] [Indexed: 11/22/2022] Open
Abstract
Lack of FMR1 protein results in fragile X syndrome (FXS), which is the most common inherited intellectual disability syndrome and serves as an excellent model disease to study molecular mechanisms resulting in neuropsychiatric comorbidities. We compared the transcriptomes of human neural progenitors (NPCs) generated from patient-derived induced pluripotent stem cells (iPSCs) of three FXS and three control male donors. Altered expression of RAD51C, PPIL3, GUCY1A2, MYD88, TRAPPC4, LYNX1, and GTF2A1L in FXS NPCs suggested changes related to triplet repeat instability, RNA splicing, testes development, and pathways previously shown to be affected in FXS. LYNX1 is a cholinergic brake of tissue plasminogen activator (tPA)-dependent plasticity, and its reduced expression was consistent with augmented tPA-dependent radial glial process growth in NPCs derived from FXS iPSC lines. There was evidence of human iPSC line donor-dependent variation reflecting potentially phenotypic variation. NPCs derived from an FXS male with concomitant epilepsy expressed differently several epilepsy-related genes, including genes shown to cause the auditory epilepsy phenotype in the murine model of FXS. Functional enrichment analysis highlighted regulation of insulin-like growth factor pathway in NPCs modeling FXS with epilepsy. Our results demonstrated potential of human iPSCs in disease modeling for discovery and development of therapeutic interventions by showing early gene expression changes in FXS iPSC-derived NPCs consistent with the known pathophysiological changes in FXS and by revealing disturbed FXS progenitor growth linked to reduced expression of LYNX1, suggesting dysregulated cholinergic system.
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Affiliation(s)
- Karo Talvio
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Rimante Minkeviciene
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kayla G. Townsley
- Pamela Sklar Division of Psychiatric Genomics, Department of Genetics and Genomics, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States,Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States,Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | | | - Laura M. Huckins
- Pamela Sklar Division of Psychiatric Genomics, Department of Genetics and Genomics, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States,Division of Molecular Psychiatry, Department of Psychiatry, Yale University, New Haven, CT, United States
| | - Padraic Corcoran
- Array and Analysis Facility, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Kristen J. Brennand
- Pamela Sklar Division of Psychiatric Genomics, Department of Genetics and Genomics, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States,Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States,Division of Molecular Psychiatry, Department of Psychiatry, Yale University, New Haven, CT, United States,Department of Genetics, Yale University, New Haven, CT, United States
| | - Maija L. Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland,*Correspondence: Maija L. Castrén,
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Kuznitsov-Yanovsky L, Shapira G, Gildin L, Shomron N, Ben-Yosef D. Transcriptomic Analysis of Human Fragile X Syndrome Neurons Reveals Neurite Outgrowth Modulation by the TGFβ/BMP Pathway. Int J Mol Sci 2022; 23:ijms23169278. [PMID: 36012539 PMCID: PMC9409179 DOI: 10.3390/ijms23169278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/11/2022] [Accepted: 08/14/2022] [Indexed: 11/25/2022] Open
Abstract
Fragile X Syndrome (FXS) is the main genetic reason for intellectual disability and is caused by the silencing of fragile X mental retardation protein (FMRP), an RNA-binding protein regulating the translation of many neuronal mRNAs. Neural differentiation of FX human embryonic stem cells (hESC) mimics the neurodevelopment of FXS fetuses and thus serves as a good model to explore the mechanisms underlining the development of FXS. Isogenic hESC clones with and without the FX mutation that share the same genetic background were in vitro differentiated into neurons, and their transcriptome was analyzed by RNA sequencing. FX neurons inactivating FMR1 expression presented delayed neuronal development and maturation, concomitant with dysregulation of the TGFβ/BMP signaling pathway, and genes related to the extracellular matrix. Migration assay showed decreased neurite outgrowth in FX neurons that was rescued by inhibition of the TGFβ/BMP signaling pathway. Our results provide new insights into the molecular pathway by which loss of FMRP affects neuronal network development. In FX neurons, the lack of FMRP dysregulates members of the BMP signaling pathway associated with ECM organization which, in a yet unknown mechanism, reduces the guidance of axonal growth cones, probably leading to the aberrant neuronal network function seen in FXS.
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Affiliation(s)
- Liron Kuznitsov-Yanovsky
- Wolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel Aviv 64239, Israel
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Guy Shapira
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Lital Gildin
- Wolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel Aviv 64239, Israel
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Noam Shomron
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Dalit Ben-Yosef
- Wolfe PGD Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital Tel-Aviv Sourasky Medical Center, Tel Aviv 64239, Israel
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
- Correspondence:
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Impaired Functional Connectivity Underlies Fragile X Syndrome. Int J Mol Sci 2022; 23:ijms23042048. [PMID: 35216162 PMCID: PMC8878121 DOI: 10.3390/ijms23042048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 01/15/2023] Open
Abstract
Fragile X syndrome (FXS), the most common form of inherited intellectual disability, is caused by a developmentally regulated silencing of the FMR1 gene, but its effect on human neuronal network development and function is not fully understood. Here, we isolated isogenic human embryonic stem cell (hESC) subclones—one with a full FX mutation and one that is free of the mutation (control) but shares the same genetic background—differentiated them into induced neurons (iNs) by forced expression of NEUROG-1, and compared the functional properties of the derived neuronal networks. High-throughput image analysis demonstrates that FX-iNs have significantly smaller cell bodies and reduced arborizations than the control. Both FX- and control-neurons can discharge repetitive action potentials, and FX neuronal networks are also able to generate spontaneous excitatory synaptic currents with slight differences from the control, demonstrating that iNs generate more mature neuronal networks than the previously used protocols. MEA analysis demonstrated that FX networks are hyperexcitable with significantly higher spontaneous burst-firing activity compared to the control. Most importantly, cross-correlation analysis enabled quantification of network connectivity to demonstrate that the FX neuronal networks are significantly less synchronous than the control, which can explain the origin of the development of intellectual dysfunction associated with FXS.
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Utami KH, Skotte NH, Colaço AR, Yusof NABM, Sim B, Yeo XY, Bae HG, Garcia-Miralles M, Radulescu CI, Chen Q, Chaldaiopoulou G, Liany H, Nama S, Peteri UKA, Sampath P, Castrén ML, Jung S, Mann M, Pouladi MA. Integrative Analysis Identifies Key Molecular Signatures Underlying Neurodevelopmental Deficits in Fragile X Syndrome. Biol Psychiatry 2020; 88:500-511. [PMID: 32653109 DOI: 10.1016/j.biopsych.2020.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 03/26/2020] [Accepted: 05/02/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by epigenetic silencing of FMR1 and loss of FMRP expression. Efforts to understand the molecular underpinnings of the disease have been largely performed in rodent or nonisogenic settings. A detailed examination of the impact of FMRP loss on cellular processes and neuronal properties in the context of isogenic human neurons remains lacking. METHODS Using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 to introduce indels in exon 3 of FMR1, we generated an isogenic human pluripotent stem cell model of FXS that shows complete loss of FMRP expression. We generated neuronal cultures and performed genome-wide transcriptome and proteome profiling followed by functional validation of key dysregulated processes. We further analyzed neurodevelopmental and neuronal properties, including neurite length and neuronal activity, using multielectrode arrays and patch clamp electrophysiology. RESULTS We showed that the transcriptome and proteome profiles of isogenic FMRP-deficient neurons demonstrate perturbations in synaptic transmission, neuron differentiation, cell proliferation and ion transmembrane transporter activity pathways, and autism spectrum disorder-associated gene sets. We uncovered key deficits in FMRP-deficient cells demonstrating abnormal neural rosette formation and neural progenitor cell proliferation. We further showed that FMRP-deficient neurons exhibit a number of additional phenotypic abnormalities, including neurite outgrowth and branching deficits and impaired electrophysiological network activity. These FMRP-deficient related impairments have also been validated in additional FXS patient-derived human-induced pluripotent stem cell neural cells. CONCLUSIONS Using isogenic human pluripotent stem cells as a model to investigate the pathophysiology of FXS in human neurons, we reveal key neural abnormalities arising from the loss of FMRP.
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Affiliation(s)
- Kagistia Hana Utami
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Niels H Skotte
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | - Ana R Colaço
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | | | - Bernice Sim
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Xin Yi Yeo
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Han-Gyu Bae
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Marta Garcia-Miralles
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Carola I Radulescu
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Qiyu Chen
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Georgia Chaldaiopoulou
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Herty Liany
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Srikanth Nama
- Institute of Medical Biology, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Ulla-Kaisa A Peteri
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Prabha Sampath
- Institute of Medical Biology, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sangyong Jung
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Matthias Mann
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | - Mahmoud A Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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5
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Das Sharma S, Pal R, Reddy BK, Selvaraj BT, Raj N, Samaga KK, Srinivasan DJ, Ornelas L, Sareen D, Livesey MR, Bassell GJ, Svendsen CN, Kind PC, Chandran S, Chattarji S, Wyllie DJA. Cortical neurons derived from human pluripotent stem cells lacking FMRP display altered spontaneous firing patterns. Mol Autism 2020; 11:52. [PMID: 32560741 PMCID: PMC7304215 DOI: 10.1186/s13229-020-00351-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 05/11/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS), a neurodevelopmental disorder, is a leading monogenetic cause of intellectual disability and autism spectrum disorder. Notwithstanding the extensive studies using rodent and other pre-clinical models of FXS, which have provided detailed mechanistic insights into the pathophysiology of this disorder, it is only relatively recently that human stem cell-derived neurons have been employed as a model system to further our understanding of the pathophysiological events that may underlie FXS. Our study assesses the physiological properties of human pluripotent stem cell-derived cortical neurons lacking fragile X mental retardation protein (FMRP). METHODS Electrophysiological whole-cell voltage- and current-clamp recordings were performed on two control and three FXS patient lines of human cortical neurons derived from induced pluripotent stem cells. In addition, we also describe the properties of an isogenic pair of lines in one of which FMR1 gene expression has been silenced. RESULTS Neurons lacking FMRP displayed bursts of spontaneous action potential firing that were more frequent but shorter in duration compared to those recorded from neurons expressing FMRP. Inhibition of large conductance Ca2+-activated K+ currents and the persistent Na+ current in control neurons phenocopies action potential bursting observed in neurons lacking FMRP, while in neurons lacking FMRP pharmacological potentiation of voltage-dependent Na+ channels phenocopies action potential bursting observed in control neurons. Notwithstanding the changes in spontaneous action potential firing, we did not observe any differences in the intrinsic properties of neurons in any of the lines examined. Moreover, we did not detect any differences in the properties of miniature excitatory postsynaptic currents in any of the lines. CONCLUSIONS Pharmacological manipulations can alter the action potential burst profiles in both control and FMRP-null human cortical neurons, making them appear like their genetic counterpart. Our studies indicate that FMRP targets that have been found in rodent models of FXS are also potential targets in a human-based model system, and we suggest potential mechanisms by which activity is altered.
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Affiliation(s)
- Shreya Das Sharma
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India.,The University of Trans-Displinary Health Sciences and Technology, Bangalore, 560064, India
| | - Rakhi Pal
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India
| | - Bharath Kumar Reddy
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India
| | - Bhuvaneish T Selvaraj
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK.,UK Dementia Research Institute at the University of Edinburgh, Edinburgh Medical School, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Nisha Raj
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Krishna Kumar Samaga
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India
| | - Durga J Srinivasan
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India.,The University of Trans-Displinary Health Sciences and Technology, Bangalore, 560064, India
| | - Loren Ornelas
- The Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.,iPSC Core, The David Janet Polak Foundation Stem Cell Core Laboratory, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.,Cedars-Sinai Biomanufacturing Center, West Hollywood, CA, 90069, USA
| | - Dhruv Sareen
- The Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.,iPSC Core, The David Janet Polak Foundation Stem Cell Core Laboratory, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.,Cedars-Sinai Biomanufacturing Center, West Hollywood, CA, 90069, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Clive N Svendsen
- The Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Peter C Kind
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India.,Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.,Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
| | - Siddharthan Chandran
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India.,Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK.,UK Dementia Research Institute at the University of Edinburgh, Edinburgh Medical School, Chancellor's Building, Edinburgh, EH16 4SB, UK.,Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
| | - Sumantra Chattarji
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India. .,Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK. .,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK. .,National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, 560065, India.
| | - David J A Wyllie
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India. .,Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK. .,Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK. .,Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.
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6
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Wu C, Zhang X, Chen P, Ruan X, Liu W, Li Y, Sun C, Hou L, Yin B, Qiang B, Shu P, Peng X. MicroRNA-129 modulates neuronal migration by targeting Fmr1 in the developing mouse cortex. Cell Death Dis 2019; 10:287. [PMID: 30911036 PMCID: PMC6433925 DOI: 10.1038/s41419-019-1517-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/30/2019] [Accepted: 03/01/2019] [Indexed: 01/05/2023]
Abstract
During cortical development, neuronal migration is one of the most important steps for normal cortical formation and function, and defects in this process cause many brain diseases. However, the molecular mechanisms underlying this process remain largely unknown. In this study, we found that miR-129-5p and miR-129-3p were expressed in both neural progenitor cells and cortical neurons in the developing murine cortex. Moreover, abnormal miR-129 expression could block radial migration of both the deeper layer and upper layer neurons, and impair the multipolar to bipolar transition. However, antagomir-mediated inhibition resulted in overmigration of neurons. In addition, we showed that Fragile X Mental Retardation gene 1 (Fmr1), which is mutated in the autism spectrum disorder fragile X syndrome, is an important regulatory target for miR-129-5p. Furthermore, Fmr1 loss-of-function and gain-of-function experiments showed opposite effects on miR-129 regulation of neuronal migration, and restoring Fmr1 expression could counteract the deleterious effect of miR-129 on neuronal migration. Taken together, our results suggest that miR-129-5p could modulate the expression of fragile X mental retardation 1 protein (FMRP) to ensure normal neuron positioning in the developing cerebral cortex.
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Affiliation(s)
- Chao Wu
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Xiaoling Zhang
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Pan Chen
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Xiangbin Ruan
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Wei Liu
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Yanchao Li
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Changjie Sun
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Lin Hou
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Bin Yin
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Boqin Qiang
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China
| | - Pengcheng Shu
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China.
| | - Xiaozhong Peng
- The State Key Laboratory of Medical Molecular Biology, Neuroscience Center, Medical Primates Research Center and Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, 100005, Beijing, China.
- Institute of Medical Biology, Chinese Academy of Medical Science and Peking Union Medical College, 650118, Kunming, China.
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7
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Pal R, Bhattacharya A. Modelling Protein Synthesis as A Biomarker in Fragile X Syndrome Patient-Derived Cells. Brain Sci 2019; 9:E59. [PMID: 30862080 PMCID: PMC6468675 DOI: 10.3390/brainsci9030059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/26/2022] Open
Abstract
The most conserved molecular phenotype of Fragile X Syndrome (FXS) is aberrant protein synthesis. This has been validated in a variety of experimental model systems from zebrafish to rats, patient-derived lymphoblasts and fibroblasts. With the advent of personalized medicine paradigms, patient-derived cells and their derivatives are gaining more translational importance, not only to model disease in a dish, but also for biomarker discovery. Here we review past and current practices of measuring protein synthesis in FXS, studies in patient derived cells and the inherent challenges in measuring protein synthesis in them to offer usable avenues of modeling this important metabolic metric for further biomarker development.
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Affiliation(s)
- Rakhi Pal
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, GKVK Post, Bellary Road, Bengaluru 560065, India.
| | - Aditi Bhattacharya
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, GKVK Post, Bellary Road, Bengaluru 560065, India.
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8
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Kuznitsov-Yanovsky L, Mayshar Y, Ben-Yosef D. Modeling FXS: Human Pluripotent Stem Cells and In Vitro Neural Differentiation. Methods Mol Biol 2019; 1942:89-100. [PMID: 30900178 DOI: 10.1007/978-1-4939-9080-1_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In fragile X syndrome (FXS) embryos FMRP is widely expressed during early stages of embryogenesis however it is inactivated by the end of the first trimester. In the same manner, human embryonic stem cell (hESC) lines from FXS blastocysts, bearing the full CGG expansion mutation, express FMRP in their pluripotent stage and in neurons derived following in vitro differentiation, FMR1 is completely silenced. Therefore, in vitro neural differentiation of FX-hESC lines serves as a uniquely valuable model system to study the developmental mechanisms underlying FXS, together with the proper differentiation protocol to mimic the neurodevelopmental process occurs in vivo.
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Affiliation(s)
- Liron Kuznitsov-Yanovsky
- Wolfe PGD Stem Cell Lab, Racine IVF Unit at Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.,Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Mayshar
- Wolfe PGD Stem Cell Lab, Racine IVF Unit at Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Dalit Ben-Yosef
- Wolfe PGD Stem Cell Lab, Racine IVF Unit at Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
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9
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Patzlaff NE, Shen M, Zhao X. Regulation of Adult Neurogenesis by the Fragile X Family of RNA Binding Proteins. Brain Plast 2018; 3:205-223. [PMID: 30151344 PMCID: PMC6091053 DOI: 10.3233/bpl-170061] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The fragile X mental retardation protein (FMRP) has an important role in neural development. Functional loss of FMRP in humans leads to fragile X syndrome, and it is the most common monogenetic contributor to intellectual disability and autism. FMRP is part of a larger family of RNA-binding proteins known as FXRs, which also includes fragile X related protein 1 (FXR1P) and fragile X related protein 2 (FXR2P). Despite the similarities of the family members, the functions of FXR1P and FXR2P in human diseases remain unclear. Although most studies focus on FMRP's role in mature neurons, all three FXRs regulate adult neurogenesis. Extensive studies have demonstrated important roles of adult neurogenesis in neuroplasticity, learning, and cognition. Impaired adult neurogenesis is implicated in neuropsychiatric disorders, neurodegenerative diseases, and neurodevelopmental disorders. Interventions aimed at regulating adult neurogenesis are thus being evaluated as potential therapeutic strategies. Here, we review and discuss the functions of FXRs in adult neurogenesis and their known similarities and differences. Understanding the overlapping regulatory functions of FXRs in adult neurogenesis can give us insights into the adult brain and fragile X syndrome.
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Affiliation(s)
- Natalie E. Patzlaff
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
- Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Minjie Shen
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
- Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
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10
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Sunamura N, Iwashita S, Enomoto K, Kadoshima T, Isono F. Loss of the fragile X mental retardation protein causes aberrant differentiation in human neural progenitor cells. Sci Rep 2018; 8:11585. [PMID: 30072797 PMCID: PMC6072755 DOI: 10.1038/s41598-018-30025-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022] Open
Abstract
Fragile X syndrome (FXS) is caused by transcriptional silencing of the FMR1 gene during embryonic development with the consequent loss of the encoded fragile X mental retardation protein (FMRP). The pathological mechanisms of FXS have been extensively studied using the Fmr1-knockout mouse, and the findings suggest important roles for FMRP in synaptic plasticity and proper functioning of neural networks. However, the function of FMRP during early development in the human nervous system remains to be confirmed. Here we describe human neural progenitor cells (NPCs) as a model for studying FMRP functions and FXS pathology. Transcriptome analysis of the NPCs derived from FMR1-knockout human induced pluripotent stem cells (iPSCs) showed altered expression of neural differentiation markers, particularly a marked induction of the astrocyte marker glial fibrillary acidic protein (GFAP). When induced to differentiate, FMRP-deficient neurons continued to express GFAP, and showed less spontaneous calcium bursts than the parental iPSC-derived neurons. Interestingly, the aberrant expression of GFAP and the impaired firing was corrected by treatment with the protein kinase inhibitor LX7101. These findings underscore the modulatory roles of FMRP in human neurogenesis, and further demonstrate that the defective phenotype of FXS could be reversed at least partly by small molecule kinase inhibitors.
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Affiliation(s)
- Naohiro Sunamura
- Asubio Pharma Co., Ltd., 6-4-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Shinzo Iwashita
- Asubio Pharma Co., Ltd., 6-4-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Kei Enomoto
- Asubio Pharma Co., Ltd., 6-4-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Taisuke Kadoshima
- Asubio Pharma Co., Ltd., 6-4-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
| | - Fujio Isono
- Asubio Pharma Co., Ltd., 6-4-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
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11
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Banerjee A, Ifrim MF, Valdez AN, Raj N, Bassell GJ. Aberrant RNA translation in fragile X syndrome: From FMRP mechanisms to emerging therapeutic strategies. Brain Res 2018; 1693:24-36. [PMID: 29653083 PMCID: PMC7377270 DOI: 10.1016/j.brainres.2018.04.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/30/2018] [Accepted: 04/06/2018] [Indexed: 02/07/2023]
Abstract
Research in the past decades has unfolded the multifaceted role of Fragile X mental retardation protein (FMRP) and how its absence contributes to the pathophysiology of Fragile X syndrome (FXS). Excess signaling through group 1 metabotropic glutamate receptors is commonly observed in mouse models of FXS, which in part is attributed to dysregulated translation and downstream signaling. Considering the wide spectrum of cellular and physiologic functions that loss of FMRP can affect in general, it may be advantageous to pursue disease mechanism based treatments that directly target translational components or signaling factors that regulate protein synthesis. Various FMRP targets upstream and downstream of the translational machinery are therefore being investigated to further our understanding of the molecular mechanism of RNA and protein synthesis dysregulation in FXS as well as test their potential role as therapeutic interventions to alleviate FXS associated symptoms. In this review, we will broadly discuss recent advancements made towards understanding the role of FMRP in translation regulation, new pre-clinical animal models with FMRP targets located at different levels of the translational and signal transduction pathways for therapeutic intervention as well as future use of stem cells to model FXS associated phenotypes.
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Affiliation(s)
- Anwesha Banerjee
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Marius F Ifrim
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Arielle N Valdez
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nisha Raj
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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12
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Achuta VS, Möykkynen T, Peteri UK, Turconi G, Rivera C, Keinänen K, Castrén ML. Functional changes of AMPA responses in human induced pluripotent stem cell-derived neural progenitors in fragile X syndrome. Sci Signal 2018; 11:11/513/eaan8784. [PMID: 29339535 DOI: 10.1126/scisignal.aan8784] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Altered neuronal network formation and function involving dysregulated excitatory and inhibitory circuits are associated with fragile X syndrome (FXS). We examined functional maturation of the excitatory transmission system in FXS by investigating the response of FXS patient-derived neural progenitor cells to the glutamate analog (AMPA). Neural progenitors derived from induced pluripotent stem cell (iPSC) lines generated from boys with FXS had augmented intracellular Ca2+ responses to AMPA and kainate that were mediated by Ca2+-permeable AMPA receptors (CP-AMPARs) lacking the GluA2 subunit. Together with the enhanced differentiation of glutamate-responsive cells, the proportion of CP-AMPAR and N-methyl-d-aspartate (NMDA) receptor-coexpressing cells was increased in human FXS progenitors. Differentiation of cells lacking GluA2 was also increased and paralleled the increased inward rectification in neural progenitors derived from Fmr1-knockout mice (the FXS mouse model). Human FXS progenitors had increased the expression of the precursor and mature forms of miR-181a, a microRNA that represses translation of the transcript encoding GluA2. Blocking GluA2-lacking, CP-AMPARs reduced the neurite length of human iPSC-derived control progenitors and further reduced the shortened length of neurites in human FXS progenitors, supporting the contribution of CP-AMPARs to the regulation of progenitor differentiation. Furthermore, we observed reduced expression of Gria2 (the GluA2-encoding gene) in the frontal lobe of FXS mice, consistent with functional changes of AMPARs in FXS. Increased Ca2+ influx through CP-AMPARs may increase the vulnerability and affect the differentiation and migration of distinct cell populations, which may interfere with normal circuit formation in FXS.
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Affiliation(s)
- Venkat Swaroop Achuta
- Department of Physiology, Faculty of Medicine, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland
| | - Tommi Möykkynen
- Division of Biochemistry and Biotechnology, Department of Biosciences, University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland
| | - Ulla-Kaisa Peteri
- Department of Physiology, Faculty of Medicine, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland
| | - Giorgio Turconi
- Department of Physiology, Faculty of Medicine, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland
| | - Claudio Rivera
- Neuroscience Center, University of Helsinki, P.O. Box 56, FIN-00014 Helsinki, Finland.,Institut de Neurobiologie de la Méditerranée, INSERM, Unité 901, 13009 Marseille, France.,Aix-Marseille Université, Unité Mixte de Recherche 901, 13273 Marseille, France
| | - Kari Keinänen
- Division of Biochemistry and Biotechnology, Department of Biosciences, University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland. .,Rinnekoti Foundation, Rinnekodintie 10, FIN-02980 Espoo, Finland.,Autism Foundation, Kuortaneenkatu 7B, FIN-00520 Helsinki, Finland
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13
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Modelling Autistic Neurons with Induced Pluripotent Stem Cells. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2017; 224:49-64. [DOI: 10.1007/978-3-319-52498-6_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
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14
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Vershkov D, Benvenisty N. Human pluripotent stem cells in modeling human disorders: the case of fragile X syndrome. Regen Med 2017; 12:53-68. [DOI: 10.2217/rme-2016-0100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Human pluripotent stem cells (PSCs) generated from affected blastocysts or from patient-derived somatic cells are an emerging platform for disease modeling and drug discovery. Fragile X syndrome (FXS), the leading cause of inherited intellectual disability, was one of the first disorders modeled in both embryonic stem cells and induced PCSs and can serve as an exemplary case for the utilization of human PSCs in the study of human diseases. Over the past decade, FXS-PSCs have been used to address the fundamental questions regarding the pathophysiology of FXS. In this review we summarize the methodologies for generation of FXS-PSCs, discuss their advantages and disadvantages compared with existing modeling systems and describe their utilization in the study of FXS pathogenesis and in the development of targeted treatment.
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Affiliation(s)
- Dan Vershkov
- The Azrieli Center for Stem Cells & Genetic Research, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| | - Nissim Benvenisty
- The Azrieli Center for Stem Cells & Genetic Research, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
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15
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Khalfallah O, Jarjat M, Davidovic L, Nottet N, Cestèle S, Mantegazza M, Bardoni B. Depletion of the Fragile X Mental Retardation Protein in Embryonic Stem Cells Alters the Kinetics of Neurogenesis. Stem Cells 2016; 35:374-385. [PMID: 27664080 DOI: 10.1002/stem.2505] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 08/07/2016] [Accepted: 08/30/2016] [Indexed: 01/14/2023]
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and a leading cause of autism. FXS is due to the silencing of the Fragile X Mental Retardation Protein (FMRP), an RNA binding protein mainly involved in translational control, dendritic spine morphology and synaptic plasticity. Despite extensive studies, there is currently no cure for FXS. With the purpose to decipher the initial molecular events leading to this pathology, we developed a stem-cell-based disease model by knocking-down the expression of Fmr1 in mouse embryonic stem cells (ESCs). Repressing FMRP in ESCs increased the expression of amyloid precursor protein (APP) and Ascl1. When inducing neuronal differentiation, βIII-tubulin, p27kip1 , NeuN, and NeuroD1 were upregulated, leading to an accelerated neuronal differentiation that was partially compensated at later stages. Interestingly, we observed that neurogenesis is also accelerated in the embryonic brain of Fmr1-knockout mice, indicating that our cellular model recapitulates the molecular alterations present in vivo. Importantly, we rescued the main phenotype of the Fmr1 knockdown cell line, not only by reintroducing FMRP but also by pharmacologically targeting APP processing, showing the role of this protein in the pathophysiology of FXS during the earliest steps of neurogenesis. Our work allows to define an early therapeutic window but also to identify more effective molecules for treating this disorder. Stem Cells 2017;35:374-385.
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Affiliation(s)
- Olfa Khalfallah
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France.,CNRS, LIA « NEOGENEX », Valbonne Sophia-Antipolis, France
| | - Marielle Jarjat
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France.,CNRS, LIA « NEOGENEX », Valbonne Sophia-Antipolis, France
| | - Laetitia Davidovic
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France
| | - Nicolas Nottet
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France
| | - Sandrine Cestèle
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France
| | - Massimo Mantegazza
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France
| | - Barbara Bardoni
- Université Côte d'Azur, Nice, France.,CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France.,CNRS, LIA « NEOGENEX », Valbonne Sophia-Antipolis, France
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16
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Mor-Shaked H, Eiges R. Modeling Fragile X Syndrome Using Human Pluripotent Stem Cells. Genes (Basel) 2016; 7:genes7100077. [PMID: 27690107 PMCID: PMC5083916 DOI: 10.3390/genes7100077] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/02/2016] [Accepted: 09/12/2016] [Indexed: 02/06/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from a loss-of-function mutation by a CGG repeat expansion at the 5′ untranslated region of the X-linked fragile X mental retardation 1 (FMR1) gene. Expansion of the CGG repeats beyond 200 copies results in protein deficiency by leading to aberrant methylation of the FMR1 promoter and the switch from active to repressive histone modifications. Additionally, the CGGs become increasingly unstable, resulting in high degree of variation in expansion size between and within tissues of affected individuals. It is still unclear how the FMR1 protein (FMRP) deficiency leads to disease pathology in neurons. Nor do we know the mechanisms by which the CGG expansion results in aberrant DNA methylation, or becomes unstable in somatic cells of patients, at least in part due to the lack of appropriate animal or cellular models. This review summarizes the current contribution of pluripotent stem cells, mutant human embryonic stem cells, and patient-derived induced pluripotent stem cells to disease modeling of FXS for basic and applied research, including the development of new therapeutic approaches.
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Affiliation(s)
- Hagar Mor-Shaked
- Stem Cell Research Laboratory, Medical Genetics Institute, Shaare Zedek Medical Center Affiliated with the Hebrew University School of Medicine, Jerusalem 91031, Israel.
| | - Rachel Eiges
- Stem Cell Research Laboratory, Medical Genetics Institute, Shaare Zedek Medical Center Affiliated with the Hebrew University School of Medicine, Jerusalem 91031, Israel.
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17
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Bostrom C, Yau SY, Majaess N, Vetrici M, Gil-Mohapel J, Christie BR. Hippocampal dysfunction and cognitive impairment in Fragile-X Syndrome. Neurosci Biobehav Rev 2016; 68:563-574. [DOI: 10.1016/j.neubiorev.2016.06.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/21/2016] [Accepted: 06/22/2016] [Indexed: 01/03/2023]
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18
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Telias M, Mayshar Y, Amit A, Ben-Yosef D. Molecular mechanisms regulating impaired neurogenesis of fragile X syndrome human embryonic stem cells. Stem Cells Dev 2016; 24:2353-65. [PMID: 26393806 DOI: 10.1089/scd.2015.0220] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited cognitive impairment. It is caused by developmental inactivation of the FMR1 gene and the absence of its encoded protein FMRP, which plays pivotal roles in brain development and function. In FXS embryos with full FMR1 mutation, FMRP is expressed during early embryogenesis and is gradually downregulated at the third trimester of pregnancy. FX-human embryonic stem cells (FX-hESCs), derived from FX human blastocysts, demonstrate the same pattern of developmentally regulated FMR1 inactivation when subjected to in vitro neural differentiation (IVND). In this study, we used this in vitro human platform to explore the molecular mechanisms downstream to FMRP in the context of early human embryonic neurogenesis. Our results show a novel role for the SOX superfamily of transcription factors, specifically for SOX2 and SOX9, which could explain the reduced and delayed neurogenesis observed in FX cells. In addition, we assess in this study the "GSK3β theory of FXS" for the first time in a human-based model. We found no evidence for a pathological increase in GSK3β protein levels upon cellular loss of FMRP, in contrast to what was found in the brain of Fmr1 knockout mice. Our study adds novel data on potential downstream targets of FMRP and highlights the importance of the FX-hESC IVND system.
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Affiliation(s)
- Michael Telias
- 1 The Wolfe PGD-SC Lab, Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center , Tel Aviv, Israel .,2 Department of Cell and Developmental Biology Sackler Medical School, Tel Aviv University , Tel Aviv, Israel
| | - Yoav Mayshar
- 1 The Wolfe PGD-SC Lab, Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center , Tel Aviv, Israel
| | - Ami Amit
- 1 The Wolfe PGD-SC Lab, Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center , Tel Aviv, Israel
| | - Dalit Ben-Yosef
- 1 The Wolfe PGD-SC Lab, Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center , Tel Aviv, Israel .,2 Department of Cell and Developmental Biology Sackler Medical School, Tel Aviv University , Tel Aviv, Israel
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19
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Bowers M, Jessberger S. Linking adult hippocampal neurogenesis with human physiology and disease. Dev Dyn 2016; 245:702-9. [PMID: 26890418 DOI: 10.1002/dvdy.24396] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/12/2016] [Accepted: 02/12/2016] [Indexed: 01/13/2023] Open
Abstract
We here review the existing evidence linking adult hippocampal neurogenesis and human brain function in physiology and disease. Furthermore, we aim to point out where evidence is missing, highlight current promising avenues of investigation, and suggest future tools and approaches to foster the link between life-long neurogenesis and human brain function. Developmental Dynamics 245:702-709, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Megan Bowers
- Laboratory of Neural Plasticity, Faculty of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Sebastian Jessberger
- Laboratory of Neural Plasticity, Faculty of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
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20
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Abstract
UNLABELLED Fragile X syndrome (FXS), the most common form of inherited mental retardation, is a neurodevelopmental disorder caused by silencing of the FMR1 gene, which in FXS becomes inactivated during human embryonic development. We have shown recently that this process is recapitulated by in vitro neural differentiation of FX human embryonic stem cells (FX-hESCs), derived from FXS blastocysts. In the present study, we analyzed morphological and functional properties of neurons generated from FX-hESCs. Human FX neurons can fire single action potentials (APs) to depolarizing current commands, but are unable to discharge trains of APs. Their APs are of a reduced amplitudes and longer durations than controls. These are reflected in reduced inward Na(+) and outward K(+) currents. In addition, human FX neurons contain fewer synaptic vesicles and lack spontaneous synaptic activity. Notably, synaptic activity in these neurons can be restored by coculturing them with normal rat hippocampal neurons, demonstrating a critical role for synaptic mechanisms in FXS pathology. This is the first extensive functional analysis of human FX neurons derived in vitro from hESCs that provides a convenient tool for studying molecular mechanisms underlying the impaired neuronal functions in FXS. SIGNIFICANCE STATEMENT Fragile X syndrome (FXS), the most common form of inherited mental retardation, is caused by silencing of the FMR1 gene. In this study, we describe for the first time the properties of neurons developed from human embryonic stem cells (hESCs) that carry the FMR1 mutation and are grown in culture for extended periods. These neurons are retarded compared with controls in several morphological and functional properties. In vitro neural differentiation of FX hESCs can thus serve as a most relevant system for the analysis of molecular mechanisms underlying the impaired neuronal functions in FXS.
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21
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Gerhardt J. Epigenetic modifications in human fragile X pluripotent stem cells; Implications in fragile X syndrome modeling. Brain Res 2015; 1656:55-62. [PMID: 26475977 DOI: 10.1016/j.brainres.2015.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/18/2015] [Accepted: 10/02/2015] [Indexed: 12/18/2022]
Abstract
Patients with fragile X syndrome (FXS) exhibit moderate to severe intellectual disabilities. In addition, one-third of FXS patients show characteristics of autism spectrum disorder. FXS is caused by a trinucleotide repeat expansion, which leads to silencing of the fragile X mental retardation (FMR1) gene. The absence of the FMR1 gene product, FMRP, is the reason for the disease symptoms. It has been suggested that repeat instability and transcription of the FMR1 gene occur during early embryonic development, while after cell differentiation repeats become stable and the FMR1 gene is silent. Epigenetic marks, such as DNA methylation, are associated with gene silencing and repeat stability at the FMR1 locus. However, the mechanisms leading to gene silencing and repeat expansion are still ambiguous, because studies at the human genomic locus were limited until now. The FXS pluripotent stem cells, recently derived from FXS adult cells and FXS blastocysts, are new useful tools to examine these mechanisms at the human endogenous FMR1 locus. This review summarizes the epigenetic features and experimental studies of FXS human embryonic and FXS induced pluripotent stem cells, generated so far. This article is part of a Special Issue entitled SI: Exploiting human neurons.
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Affiliation(s)
- Jeannine Gerhardt
- Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx 10461, USA.
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22
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Halevy T, Czech C, Benvenisty N. Molecular mechanisms regulating the defects in fragile X syndrome neurons derived from human pluripotent stem cells. Stem Cell Reports 2015; 4:37-46. [PMID: 25483109 PMCID: PMC4297868 DOI: 10.1016/j.stemcr.2014.10.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 10/29/2014] [Accepted: 10/29/2014] [Indexed: 11/27/2022] Open
Abstract
Fragile X syndrome (FXS) is caused by the absence of the fragile X mental retardation protein (FMRP). We have previously generated FXS-induced pluripotent stem cells (iPSCs) from patients' fibroblasts. In this study, we aimed at unraveling the molecular phenotype of the disease. Our data revealed aberrant regulation of neural differentiation and axon guidance genes in FXS-derived neurons, which are regulated by the RE-1 silencing transcription factor (REST). Moreover, we found REST to be elevated in FXS-derived neurons. As FMRP is involved in the microRNA (miRNA) pathway, we employed miRNA-array analyses and uncovered several miRNAs dysregulated in FXS-derived neurons. We found hsa-mir-382 to be downregulated in FXS-derived neurons, and introduction of mimic-mir-382 into these neurons was sufficient to repress REST and upregulate its axon guidance target genes. Our data link FMRP and REST through the miRNA pathway and show a new aspect in the development of FXS.
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Affiliation(s)
- Tomer Halevy
- Azrieli Center for Stem Cells and Genetic Research, Department of Genetics, Institute of Life Sciences, The Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Christian Czech
- Roche Pharmaceutical Research & Early Development, Neuroscience, Roche Innovation Center, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Nissim Benvenisty
- Azrieli Center for Stem Cells and Genetic Research, Department of Genetics, Institute of Life Sciences, The Hebrew University, Givat-Ram, Jerusalem 91904, Israel.
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Abstract
Fragile X Syndrome (FXS) is commonly thought to arise from dysfunction of the synapse, the site of communication between neurons. However, loss of the protein that results in FXS occurs early in embryonic development, while synapses are formed relatively late. Fragile X Syndrome (FXS) is the leading known monogenic form of autism and the most common form of inherited intellectual disability. FXS results from silencing the FMR1 gene during embryonic development, leading to loss of Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein that regulates mRNA transport, stability, and translation. FXS is commonly thought of as a disease of synaptic dysfunction; however, FMRP expression is lost early in embryonic development, well before most synaptogenesis occurs. Recent studies suggest that loss of FMRP results in aberrant neurogenesis, but neurogenic defects have been variable. We investigated whether FMRP affects neurogenesis in Xenopus laevis tadpoles that express a homolog of FMR1. We used in vivo time-lapse imaging of neural progenitor cells and their neuronal progeny to evaluate the effect of acute loss or overexpression of FMRP on neurogenesis in the developing optic tectum. We complimented the time-lapse studies with SYTOX labeling to quantify apoptosis and CldU labeling to measure cell proliferation. Animals with increased or decreased levels of FMRP have significantly decreased neuronal proliferation and survival. They also have increased neuronal differentiation, but deficient dendritic arbor elaboration. The presence and severity of these defects was highly sensitive to FMRP levels. These data demonstrate that FMRP plays an important role in neurogenesis and suggest that endogenous FMRP levels are carefully regulated. These studies show promise in using Xenopus as an experimental system to study fundamental deficits in brain development with loss of FMRP and give new insight into the pathophysiology of FXS.
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24
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La Fata G, Gärtner A, Domínguez-Iturza N, Dresselaers T, Dawitz J, Poorthuis RB, Averna M, Himmelreich U, Meredith RM, Achsel T, Dotti CG, Bagni C. FMRP regulates multipolar to bipolar transition affecting neuronal migration and cortical circuitry. Nat Neurosci 2014; 17:1693-700. [PMID: 25402856 DOI: 10.1038/nn.3870] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/16/2014] [Indexed: 12/20/2022]
Abstract
Deficiencies in fragile X mental retardation protein (FMRP) are the most common cause of inherited intellectual disability, fragile X syndrome (FXS), with symptoms manifesting during infancy and early childhood. Using a mouse model for FXS, we found that Fmrp regulates the positioning of neurons in the cortical plate during embryonic development, affecting their multipolar-to-bipolar transition (MBT). We identified N-cadherin, which is crucial for MBT, as an Fmrp-regulated target in embryonic brain. Furthermore, spontaneous network activity and high-resolution brain imaging revealed defects in the establishment of neuronal networks at very early developmental stages, further confirmed by an unbalanced excitatory and inhibitory network. Finally, reintroduction of Fmrp or N-cadherin in the embryo normalized early postnatal neuron activity. Our findings highlight the critical role of Fmrp in the developing cerebral cortex and might explain some of the clinical features observed in patients with FXS, such as alterations in synaptic communication and neuronal network connectivity.
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Affiliation(s)
- Giorgio La Fata
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium
| | - Annette Gärtner
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium
| | - Nuria Domínguez-Iturza
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium
| | | | - Julia Dawitz
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, Amsterdam, the Netherlands
| | - Rogier B Poorthuis
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, Amsterdam, the Netherlands
| | - Michele Averna
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium
| | | | - Rhiannon M Meredith
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, Amsterdam, the Netherlands
| | - Tilmann Achsel
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium
| | - Carlos G Dotti
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium. [3] Centro de Biología Molecular Severo Ochoa, Campus de la Universidad Autónoma de Madrid, Spain
| | - Claudia Bagni
- 1] VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium. [2] Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, Leuven, Belgium. [3] Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
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25
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Brick DJ, Nethercott HE, Montesano S, Banuelos MG, Stover AE, Schutte SS, O'Dowd DK, Hagerman RJ, Ono M, Hessl DR, Tassone F, Schwartz PH. The Autism Spectrum Disorders Stem Cell Resource at Children's Hospital of Orange County: Implications for Disease Modeling and Drug Discovery. Stem Cells Transl Med 2014; 3:1275-86. [PMID: 25273538 PMCID: PMC4214842 DOI: 10.5966/sctm.2014-0073] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/15/2014] [Indexed: 12/28/2022] Open
Abstract
The autism spectrum disorders (ASDs) comprise a set of neurodevelopmental disorders that are, at best, poorly understood but are the fastest growing developmental disorders in the United States. Because animal models of polygenic disorders such as the ASDs are difficult to validate, the derivation of induced pluripotent stem cells (iPSCs) by somatic cell reprogramming offers an alternative strategy for identifying the cellular mechanisms contributing to ASDs and the development of new treatment options. Access to statistically relevant numbers of ASD patient cell lines, however, is still a limiting factor for the field. We describe a new resource with more than 200 cell lines (fibroblasts, iPSC clones, neural stem cells, glia) from unaffected volunteers and patients with a wide range of clinical ASD diagnoses, including fragile X syndrome. We have shown that both normal and ASD-specific iPSCs can be differentiated toward a neural stem cell phenotype and terminally differentiated into action-potential firing neurons and glia. The ability to evaluate and compare data from a number of different cell lines will facilitate greater insight into the cause or causes and biology of the ASDs and will be extremely useful for uncovering new therapeutic and diagnostic targets. Some drug treatments have already shown promise in reversing the neurobiological abnormalities in iPSC-based models of ASD-associated diseases. The ASD Stem Cell Resource at the Children's Hospital of Orange County will continue expanding its collection and make all lines available on request with the goal of advancing the use of ASD patient cells as disease models by the scientific community.
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Affiliation(s)
- David J Brick
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Hubert E Nethercott
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Samantha Montesano
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Maria G Banuelos
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Alexander E Stover
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Soleil Sun Schutte
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Diane K O'Dowd
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Randi J Hagerman
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Michele Ono
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - David R Hessl
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Flora Tassone
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
| | - Philip H Schwartz
- National Human Neural Stem Cell Resource, Centers for Neuroscience and Translational Research, Children's Hospital of Orange County Research Institute, Orange, California, USA; Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Department of Pediatrics, and Department of Biochemistry and Molecular Medicine, University of California, Davis, Sacramento, California, USA
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26
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Li Y, Zhao X. Concise review: Fragile X proteins in stem cell maintenance and differentiation. Stem Cells 2014; 32:1724-33. [PMID: 24648324 PMCID: PMC4255947 DOI: 10.1002/stem.1698] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 02/18/2014] [Accepted: 03/01/2014] [Indexed: 12/15/2022]
Abstract
Fragile X syndrome (FXS), the most common genetic form of autism spectrum disorder, is caused by deficiency of the fragile X mental retardation protein (FMRP). Despite extensive research and scientific progress, understanding how FMRP regulates brain development and function remains a major challenge. FMRP is a neuronal RNA-binding protein that binds about a third of messenger RNAs in the brain and controls their translation, stability, and cellular localization. The absence of FMRP results in increased protein synthesis, leading to enhanced signaling in a number of intracellular pathways, including the mTOR, mGLuR5, ERK, Gsk3β, PI3K, and insulin pathways. Until recently, FXS was largely considered a deficit of mature neurons; however, a number of new studies have shown that FMRP may also play important roles in stem cells, among them neural stem cells, germline stem cells, and pluripotent stem cells. In this review, we will cover these newly discovered functions of FMRP, as well as the other two fragile X-related proteins, in stem cells. We will also discuss the literature on the use of stem cells, particularly neural stem cells and induced pluripotent stem cells, as model systems for studying the functions of FMRP in neuronal development.
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Affiliation(s)
- Yue Li
- Waisman Center and Department of Neuroscience, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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27
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Doers ME, Musser MT, Nichol R, Berndt ER, Baker M, Gomez TM, Zhang SC, Abbeduto L, Bhattacharyya A. iPSC-derived forebrain neurons from FXS individuals show defects in initial neurite outgrowth. Stem Cells Dev 2014; 23:1777-87. [PMID: 24654675 DOI: 10.1089/scd.2014.0030] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and is closely linked with autism. The genetic basis of FXS is an expansion of CGG repeats in the 5'-untranslated region of the FMR1 gene on the X chromosome leading to the loss of expression of the fragile X mental retardation protein (FMRP). The cause of FXS has been known for over 20 years, yet the full molecular and cellular consequences of this mutation remain unclear. Although mouse and fly models have provided significant understanding of this disorder and its effects on the central nervous system, insight from human studies is limited. We have created human induced pluripotent stem cell (iPSC) lines from fibroblasts obtained from individuals with FXS to enable in vitro modeling of the human disease. Three young boys with FXS who came from a well-characterized cohort representative of the range of affectedness typical for the syndrome were recruited to aid in linking cellular and behavioral phenotypes. The FMR1 mutation is preserved during the reprogramming of patient fibroblasts to iPSCs. Mosaicism of the CGG repeat length in one of the patient's fibroblasts allowed for the generation of isogenic lines with differing CGG repeat lengths from the same patient. FXS forebrain neurons were differentiated from these iPSCs and display defective neurite initiation and extension. These cells provide a well-characterized resource to examine potential neuronal deficits caused by FXS as well as the function of FMRP in human neurons.
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Affiliation(s)
- Matthew E Doers
- 1 Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison , Madison, Wisconsin
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28
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Tissue plasminogen activator contributes to alterations of neuronal migration and activity-dependent responses in fragile X mice. J Neurosci 2014; 34:1916-23. [PMID: 24478370 DOI: 10.1523/jneurosci.3753-13.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited neurodevelopmental disorder with intellectual disability. Here, we show that the expression of tissue plasminogen activator (tPA) is increased in glial cells differentiated from neural progenitors of Fmr1 knock-out mice, a mouse model for FXS, and that tPA is involved in the altered migration and differentiation of these progenitors lacking FMR1 protein (FMRP). When tPA function is blocked with an antibody, enhanced migration of doublecortin-immunoreactive neurons in 1 d differentiated FMRP-deficient neurospheres is normalized. In time-lapse imaging, blocking the tPA function promotes early glial differentiation and reduces the velocity of nuclear movement of FMRP-deficient radial glia. In addition, we show that enhanced intracellular Ca(2+) responses to depolarization with potassium are prevented by the treatment with the tPA-neutralizing antibody in FMRP-deficient cells during early neural progenitor differentiation. Alterations of the tPA expression in the embryonic, postnatal, and adult brain of Fmr1 knock-out mice suggest an important role for tPA in the abnormal neuronal differentiation and plasticity in FXS. Altogether, the results indicate that tPA may prove to be an interesting potential target for pharmacological intervention in FXS.
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29
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Cook D, Nuro E, Murai KK. Increasing our understanding of human cognition through the study of Fragile X Syndrome. Dev Neurobiol 2013; 74:147-77. [PMID: 23723176 PMCID: PMC4216185 DOI: 10.1002/dneu.22096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 05/17/2013] [Indexed: 12/16/2022]
Abstract
Fragile X Syndrome (FXS) is considered the most common form of inherited intellectual disability. It is caused by reductions in the expression level or function of a single protein, the Fragile X Mental Retardation Protein (FMRP), a translational regulator which binds to approximately 4% of brain messenger RNAs. Accumulating evidence suggests that FXS is a complex disorder of cognition, involving interactions between genetic and environmental influences, leading to difficulties in acquiring key life skills including motor skills, language, and proper social behaviors. Since many FXS patients also present with one or more features of autism spectrum disorders (ASDs), insights gained from studying the monogenic basis of FXS could pave the way to a greater understanding of underlying features of multigenic ASDs. Here we present an overview of the FXS and FMRP field with the goal of demonstrating how loss of a single protein involved in translational control affects multiple stages of brain development and leads to debilitating consequences on human cognition. We also focus on studies which have rescued or improved FXS symptoms in mice using genetic or therapeutic approaches to reduce protein expression. We end with a brief description of how deficits in translational control are implicated in FXS and certain cases of ASDs, with many recent studies demonstrating that ASDs are likely caused by increases or decreases in the levels of certain key synaptic proteins. The study of FXS and its underlying single genetic cause offers an invaluable opportunity to study how a single gene influences brain development and behavior.
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Affiliation(s)
- Denise Cook
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
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30
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Mithal DS, Ren D, Miller RJ. CXCR4 signaling regulates radial glial morphology and cell fate during embryonic spinal cord development. Glia 2013; 61:1288-305. [PMID: 23828719 DOI: 10.1002/glia.22515] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 03/04/2013] [Accepted: 04/01/2013] [Indexed: 12/20/2022]
Abstract
Embryonic meninges secrete the chemokine SDF-1/CXCL12 as a chemotactic guide for migrating neural stem cells, but SDF-1 is not known to directly regulate the functions of radial glia. Recently, the developing meninges have been shown to regulate radial glial function, yet the mechanisms and signals responsible for this phenomenon remain unclear. Moreover, as a nonmigratory cell type, radial glia do not conform to traditional models associated with chemokine signaling in the central nervous system. Using fluorescent transgenes, in vivo genetic manipulations and pharmacological techniques, we demonstrate that SDF-1 derived from the meninges exerts a CXCR4-dependent effect on radial glia. Deletion of CXCR4 expression by radial glia influences their morphology, mitosis, and progression through both oligodendroglial and astroglial lineages. Additionally, disruption of CXCR4 signaling in radial glia has a transient effect on the migration of oligodendrocyte progenitors. These data indicate that a specific chemokine signal derived from the meninges has multiple regulatory effects on radial glia.
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Affiliation(s)
- Divakar S Mithal
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA
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31
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Castrén ML, Castrén E. BDNF in fragile X syndrome. Neuropharmacology 2013; 76 Pt C:729-36. [PMID: 23727436 DOI: 10.1016/j.neuropharm.2013.05.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 12/12/2022]
Abstract
Fragile X syndrome (FXS) is a monogenic disorder that is caused by the absence of FMR1 protein (FMRP). FXS serves as an excellent model disorder for studies investigating disturbed molecular mechanisms and synapse function underlying cognitive impairment, autism, and behavioral disturbance. Abnormalities in dendritic spines and synaptic transmission in the brain of FXS individuals and mouse models for FXS indicate perturbations in the development, maintenance, and plasticity of neuronal network connectivity. However, numerous alterations are found during the early development in FXS, including abnormal differentiation of neural progenitors and impaired migration of newly born neurons. Several aspects of FMRP function are modulated by brain-derived neurotrophic factor (BDNF) signaling. Here, we review the evidence of the role for BDNF in the developing and adult FXS brain. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.
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Affiliation(s)
- Maija L Castrén
- Institute of Biomedicine/Physiology, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland; Rinnekoti Foundation, Rinnekodintie 10, FIN-02980 Espoo, Finland.
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32
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Functional implications of hippocampal adult neurogenesis in intellectual disabilities. Amino Acids 2013; 45:113-31. [DOI: 10.1007/s00726-013-1489-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022]
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33
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Lewitus E, Kalinka AT. Neocortical development as an evolutionary platform for intragenomic conflict. Front Neuroanat 2013; 7:2. [PMID: 23576960 PMCID: PMC3620502 DOI: 10.3389/fnana.2013.00002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/18/2013] [Indexed: 12/21/2022] Open
Abstract
Embryonic development in mammals has evolved a platform for genomic conflict between mothers and embryos and, by extension, between maternal and paternal genomes. The evolutionary interests of the mother and embryo may be maximized through the promotion of sex-chromosome genes and imprinted alleles, resulting in the rapid evolution of postzygotic phenotypes preferential to either the maternal or paternal genome. In eutherian mammals, extraordinary in utero maternal investment in the brain, and neocortex especially, suggests that convergent evolution of an expanded mammalian neocortex along divergent lineages may be explained, in part, by parent-of-origin-linked gene expression arising from parent-offspring conflict. The influence of this conflict on neocortical development and evolution, however, has not been investigated at the genomic level. In this hypothesis and theory article, we provide preliminary evidence for positive selection in humans in the regions of two platforms of intragenomic conflict—chromosomes 15q11-q13 and X—and explore the potential relevance of cis-regulated imprinted domains to neocortical expansion in mammalian evolution. We present the hypothesis that maternal- and paternal-specific pressures on the developing neocortex compete intragenomically to influence neocortical expansion in mammalian evolution.
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Affiliation(s)
- Eric Lewitus
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
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34
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Telias M, Segal M, Ben-Yosef D. Neural differentiation of Fragile X human Embryonic Stem Cells reveals abnormal patterns of development despite successful neurogenesis. Dev Biol 2012; 374:32-45. [PMID: 23219959 DOI: 10.1016/j.ydbio.2012.11.031] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/24/2012] [Accepted: 11/28/2012] [Indexed: 12/23/2022]
Abstract
Fragile X Syndrome (FXS) is the most common form of inherited intellectual disability, caused by developmentally regulated inactivation of FMR1, leading to the absence of its encoded protein FMRP. We have previously shown that undifferentiated Fragile X human Embryonic Stem Cells (FX-hESCs) express FMRP, despite the presence of the full FMR1 mutation (>200 CGG repeats). We describe here, for the first time, in-vitro differentiation of FX-hESCs into neurons progressively inactivating FMR1. Abnormal neurogenesis and aberrant gene expression were found already during early stages of differentiation, leading to poor neuronal maturation and high gliogenic development. Human FX neurons fired action potentials but displayed poor spontaneous synaptic activity and lacked reactivity to glutamate. Our dynamic FX-hESCs model can contribute to the understanding of the sequence of developmental events taking place during neurogenesis and how they are altered in FXS individuals, leading to intellectual disability. Furthermore, it may shed light over the striking phenotypic features characterizing FXS in human.
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Affiliation(s)
- Michael Telias
- Stem Cell Research Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, 6 Weizmann St., 64239 Tel-Aviv, Israel
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35
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Brennand KJ, Simone A, Tran N, Gage FH. Modeling psychiatric disorders at the cellular and network levels. Mol Psychiatry 2012; 17:1239-53. [PMID: 22472874 PMCID: PMC3465628 DOI: 10.1038/mp.2012.20] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Although psychiatric disorders such as autism spectrum disorders, schizophrenia and bipolar disorder affect a number of brain regions and produce a complex array of clinical symptoms, basic phenotypes likely exist at the level of single neurons and simple networks. Being highly heritable, it is hypothesized that these disorders are amenable to cell-based studies in vitro. Using induced pluripotent stem cell-derived neurons and/or induced neurons from fibroblasts, limitless numbers of live human neurons can now be generated from patients with a genetic background permissive to the disease state. We predict that cell-based studies will ultimately contribute to our understanding of the initiation, progression and treatment of these psychiatric disorders.
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Affiliation(s)
- KJ Brennand
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - A Simone
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - N Tran
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - FH Gage
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
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36
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Paul K, Venkitaramani DV, Cox CL. Dampened dopamine-mediated neuromodulation in prefrontal cortex of fragile X mice. J Physiol 2012; 591:1133-43. [PMID: 23148316 DOI: 10.1113/jphysiol.2012.241067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inheritable mental retardation caused by transcriptional silencing of the Fmr1 gene resulting in the absence of fragile X mental retardation protein (FMRP). The role of this protein in neurons is complex and its absence gives rise to diverse alterations in neuronal function leading to neurological disorders including mental retardation, hyperactivity, cognitive impairment, obsessive-compulsive behaviour, seizure activity and autism. FMRP regulates mRNA translation at dendritic spines where synapses are formed, and thus the lack of FMRP can lead to disruptions in synaptic transmission and plasticity. Many of these neurological deficits in FXS probably involve the prefrontal cortex, and in this study, we have focused on modulatory actions of dopamine in the medial prefrontal cortex. Our data indicate that dopamine produces a long-lasting enhancement of evoked inhibitory postsynaptic currents (IPSCs) mediated by D1-type receptors seen in wild-type mice; however, such enhancement is absent in the Fmr1 knock-out (Fmr1 KO) mice. The facilitation of IPSCs produced by direct cAMP stimulation was unaffected in Fmr1 KO, but D1 receptor levels were reduced in these animals. Our results show significant disruption of dopaminergic modulation of synaptic transmission in the Fmr1 KO mice and this alteration in inhibitory activity may provide insight into potential targets for the rescue of deficits associated with FXS.
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Affiliation(s)
- Kush Paul
- Department of Molecular and Integrative Physiology, University of Illinois, Urbana, IL 61801, USA.
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37
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Aureli M, Gritti A, Bassi R, Loberto N, Ricca A, Chigorno V, Prinetti A, Sonnino S. Plasma membrane-associated glycohydrolases along differentiation of murine neural stem cells. Neurochem Res 2012; 37:1344-54. [PMID: 22350518 DOI: 10.1007/s11064-012-0719-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/17/2012] [Accepted: 01/28/2012] [Indexed: 12/12/2022]
Abstract
The activities of plasma membrane associated sialidase Neu3, total β-glucosidase, CBE-sensitive β-glucosidase, non-lysosomal β-glucosyl ceramidase GBA2, β-galactosidase, β-hexosaminidase and sphingomyelinase were determined at three different stages of differentiation of murine neural stem cell cultures, corresponding to precursors, commited progenitors, and differentiated cells. Cell immunostaining for specific markers of the differentiation process, performed after 7 days in culture in presence of differentiating agents, clearly showed the presence of oligodendrocytes, astrocytes and neurons. Glial cells were the most abundant. Sialidase Neu3 after a decrease from progenitors to precursors, showed an increase parallel to the differentiation process. All the other glycosidases increased their activity along differentiation. The activity of CBE-sensitive β-glucosidase and GBA2 were very similar at the precursor stage, but CBE-sensitive β-glucosidase increased 7 times while GBA2 only two in the differentiated cells. In addition, we analysed also sphingomyelinase as enzyme specifically associated to sphingolipids. The activity of this enzyme increased from precursors to differentiated cells.
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Affiliation(s)
- Massimo Aureli
- Department of Medical Chemistry, Biochemistry and Biotechnology, University of Milan, Via Fratelli Cervi 93, 20090 Segrate, Italy
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38
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Abstract
Neural stem/progenitor cell (NPC) cultures are a tool to study the differentiation of neuronal cells and can be used to model disease conditions in studies investigating the pathological mechanisms affecting the development and cellular plasticity of the central nervous system. There is evidence that abnormalities of NPCs and their differentiation contribute to the pathophysiology of fragile X syndrome. The results obtained with NPC cultures derived from human and mouse brain tissue with the fragile X mutation are in line with the abnormalities of Fmr1-knockout mouse brain in vivo indicating that NPC cultures can be useful as a model for fragile X syndrome.
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Affiliation(s)
- Maija Castrén
- Institute of Biomedicine/Physiology, University of Helsinki, Helsinki, Finland.
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39
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Epigenetic characterization of the FMR1 gene and aberrant neurodevelopment in human induced pluripotent stem cell models of fragile X syndrome. PLoS One 2011; 6:e26203. [PMID: 22022567 PMCID: PMC3192166 DOI: 10.1371/journal.pone.0026203] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 09/22/2011] [Indexed: 12/24/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability. In addition to cognitive deficits, FXS patients exhibit hyperactivity, attention deficits, social difficulties, anxiety, and other autistic-like behaviors. FXS is caused by an expanded CGG trinucleotide repeat in the 5′ untranslated region of the Fragile X Mental Retardation (FMR1) gene leading to epigenetic silencing and loss of expression of the Fragile X Mental Retardation protein (FMRP). Despite the known relationship between FMR1 CGG repeat expansion and FMR1 silencing, the epigenetic modifications observed at the FMR1 locus, and the consequences of the loss of FMRP on human neurodevelopment and neuronal function remain poorly understood. To address these limitations, we report on the generation of induced pluripotent stem cell (iPSC) lines from multiple patients with FXS and the characterization of their differentiation into post-mitotic neurons and glia. We show that clones from reprogrammed FXS patient fibroblast lines exhibit variation with respect to the predominant CGG-repeat length in the FMR1 gene. In two cases, iPSC clones contained predominant CGG-repeat lengths shorter than measured in corresponding input population of fibroblasts. In another instance, reprogramming a mosaic patient having both normal and pre-mutation length CGG repeats resulted in genetically matched iPSC clonal lines differing in FMR1 promoter CpG methylation and FMRP expression. Using this panel of patient-specific, FXS iPSC models, we demonstrate aberrant neuronal differentiation from FXS iPSCs that is directly correlated with epigenetic modification of the FMR1 gene and a loss of FMRP expression. Overall, these findings provide evidence for a key role for FMRP early in human neurodevelopment prior to synaptogenesis and have implications for modeling of FXS using iPSC technology. By revealing disease-associated cellular phenotypes in human neurons, these iPSC models will aid in the discovery of novel therapeutics for FXS and other autism-spectrum disorders sharing common pathophysiology.
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40
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Guo W, Zhang L, Christopher DM, Teng ZQ, Fausett SR, Liu C, George OL, Klingensmith J, Jin P, Zhao X. RNA-binding protein FXR2 regulates adult hippocampal neurogenesis by reducing Noggin expression. Neuron 2011; 70:924-38. [PMID: 21658585 DOI: 10.1016/j.neuron.2011.03.027] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 10/18/2022]
Abstract
In adult mammalian brains, neurogenesis persists in the subventricular zone of the lateral ventricles (SVZ) and the dentate gyrus (DG) of the hippocampus. Although evidence suggest that adult neurogenesis in these two regions is subjected to differential regulation, the underlying mechanism is unclear. Here, we show that the RNA-binding protein FXR2 specifically regulates DG neurogenesis by reducing the stability of Noggin mRNA. FXR2 deficiency leads to increased Noggin expression and subsequently reduced BMP signaling, which results in increased proliferation and altered fate specification of neural stem/progenitor cells in DG. In contrast, Noggin is not regulated by FXR2 in the SVZ, because Noggin expression is restricted to the ependymal cells of the lateral ventricles, where FXR2 is not expressed. Differential regulation of SVZ and DG stem cells by FXR2 may be a key component of the mechanism that governs the different neurogenic processes in these two adult germinal zones.
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Affiliation(s)
- Weixiang Guo
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
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41
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Gatto CL, Broadie K. Fragile X mental retardation protein is required for programmed cell death and clearance of developmentally-transient peptidergic neurons. Dev Biol 2011; 356:291-307. [PMID: 21596027 PMCID: PMC3143227 DOI: 10.1016/j.ydbio.2011.05.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 04/22/2011] [Accepted: 05/03/2011] [Indexed: 01/19/2023]
Abstract
Fragile X syndrome (FXS), caused by loss of fragile X mental retardation 1 (FMR1) gene function, is the most common heritable cause of intellectual disability and autism spectrum disorders. The FMR1 product (FMRP) is an RNA-binding protein best established to function in activity-dependent modulation of synaptic connections. In the Drosophila FXS disease model, loss of functionally-conserved dFMRP causes synaptic overgrowth and overelaboration in pigment dispersing factor (PDF) peptidergic neurons in the adult brain. Here, we identify a very different component of PDF neuron misregulation in dfmr1 mutants: the aberrant retention of normally developmentally-transient PDF tritocerebral (PDF-TRI) neurons. In wild-type animals, PDF-TRI neurons in the central brain undergo programmed cell death and complete, processive clearance within days of eclosion. In the absence of dFMRP, a defective apoptotic program leads to constitutive maintenance of these peptidergic neurons. We tested whether this apoptotic defect is circuit-specific by examining crustacean cardioactive peptide (CCAP) and bursicon circuits, which are similarly developmentally-transient and normally eliminated immediately post-eclosion. In dfmr1 null mutants, CCAP/bursicon neurons also exhibit significantly delayed clearance dynamics, but are subsequently eliminated from the nervous system, in contrast to the fully persistent PDF-TRI neurons. Thus, the requirement of dFMRP for the retention of transitory peptidergic neurons shows evident circuit specificity. The novel defect of impaired apoptosis and aberrant neuron persistence in the Drosophila FXS model suggests an entirely new level of "pruning" dysfunction may contribute to the FXS disease state.
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Affiliation(s)
- Cheryl L Gatto
- Departments of Biological Sciences and Cell and Developmental Biology, Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232, USA
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42
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Cristini S, Alessandri G, Acerbi F, Ciusani E, Colombo A, Fascio U, Nicosia RF, Invernizzi RW, Gelati M, Parati EA, Invernici G. Three-dimensional self-organizing neural architectures: a neural stem cells reservoir and a system for neurodevelopmental studies. Tissue Eng Part C Methods 2011; 17:1109-20. [PMID: 21721991 DOI: 10.1089/ten.tec.2010.0622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Complex microenvironmental stimuli influence neural cell properties. To study this, we developed a three-dimensional (3-D) neural culture system, composed of different populations including neurons, astrocytes, and neural stem cells (NSCs). In particular, these last-mentioned cells represent a source potentially exploitable to test drugs, to study neurodevelopment and cell-therapies for neuroregenerations. On seeding on matrigel in a medium supplemented with serum and mitogens, cells obtained from human fetal brain tissue formed 3-D self-organizing neural architectures. Immunocytochemical analysis demonstrated the presence of undifferentiated nestin+ and CD133+ cells, surrounded by β-tub-III+ and GFAP+ cells, suggesting the formation of niches containing potential human NSCs (hNSCs). The presence of hNSCs was confirmed by both neurosphere assay and RT-PCR, and their multipotentiality was demonstrated by both immunofluorescent staining and RT-PCR. Flow cytometry analysis revealed that neurosphere forming cells originating from at least two different subsets expressing, respectively, CD133 and CD146 markers were endowed with different proliferative and differentiation potential. Our data implicate that the complexity of environment within niches and aggregates of heterogeneous neural cell subsets may represent an innovative platform for neurobiological and neurodevelopmental investigations and a reservoir for a rapid expansion of hNSCs.
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Affiliation(s)
- Silvia Cristini
- Laboratory of Cellular Neurobiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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43
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Mattis VB, Svendsen CN. Induced pluripotent stem cells: a new revolution for clinical neurology? Lancet Neurol 2011; 10:383-94. [PMID: 21435601 DOI: 10.1016/s1474-4422(11)70022-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Why specific neuronal populations are uniquely susceptible in neurodegenerative diseases remains a mystery. Brain tissue samples from patients are rarely available for testing, and animal models frequently do not recapitulate all features of a specific disorder; therefore, pathophysiological investigations are difficult. An exciting new avenue for neurological research and drug development is the discovery that patients' somatic cells can be reprogrammed to a pluripotent state; these cells are known as induced pluripotent stem cells. Once pluripotency is reinstated, cell colonies can be expanded and differentiated into specific neural populations. The availability of these cells enables the monitoring in vitro of temporal features of disease initiation and progression, and testing of new drug treatments on the patient's own cells. Hence, this swiftly growing area of research has the potential to contribute greatly to our understanding of the pathophysiology of neurodegenerative and neurodevelopmental diseases.
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Affiliation(s)
- Virginia B Mattis
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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44
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Callan MA, Zarnescu DC. Heads-up: new roles for the fragile X mental retardation protein in neural stem and progenitor cells. Genesis 2011; 49:424-40. [PMID: 21404421 DOI: 10.1002/dvg.20745] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 02/23/2011] [Accepted: 02/27/2011] [Indexed: 11/12/2022]
Abstract
Fragile X syndrome (FXS) is the most common form of inherited mental retardation and is caused by the loss of function for Fragile X Mental Retardation Protein (FMRP), a selective RNA-binding protein with a demonstrated role in the localized translation of target mRNAs at synapses. Several recent studies provide compelling evidence for a new role of FMRP in the development of the nervous system, during neurogenesis. Using a multi-faceted approach and a variety of model systems ranging from cultured neurospheres and progenitor cells to in vivo Drosophila and mouse models these reports indicate that FMRP is required for neural stem and progenitor cell proliferation, differentiation, survival, as well as regulation of gene expression. Here we compare and contrast these recent reports and discuss the implications of FMRP's new role in embryonic and adult neurogenesis, including the development of novel therapeutic approaches to FXS and related neurological disorders such as autism.
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Affiliation(s)
- Matthew A Callan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA
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45
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Guo W, Allan AM, Zong R, Zhang L, Johnson EB, Schaller EG, Murthy AC, Goggin SL, Eisch AJ, Oostra BA, Nelson DL, Jin P, Zhao X. Ablation of Fmrp in adult neural stem cells disrupts hippocampus-dependent learning. Nat Med 2011; 17:559-65. [PMID: 21516088 DOI: 10.1038/nm.2336] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/23/2011] [Indexed: 12/14/2022]
Abstract
Deficiency in fragile X mental retardation protein (FMRP) results in fragile X syndrome (FXS), an inherited form of intellectual disability. Despite extensive research, it is unclear how FMRP deficiency contributes to the cognitive deficits in FXS. Fmrp-null mice show reduced adult hippocampal neurogenesis. As Fmrp is also enriched in mature neurons, we investigated the function of Fmrp expression in neural stem and progenitor cells (aNSCs) and its role in adult neurogenesis. Here we show that ablation of Fmrp in aNSCs by inducible gene recombination leads to reduced hippocampal neurogenesis in vitro and in vivo, as well as markedly impairing hippocampus-dependent learning in mice. Conversely, restoration of Fmrp expression specifically in aNSCs rescues these learning deficits in Fmrp-deficient mice. These data suggest that defective adult neurogenesis may contribute to the learning impairment seen in FXS, and these learning deficits can be rectified by delayed restoration of Fmrp specifically in aNSCs.
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Affiliation(s)
- Weixiang Guo
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
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46
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Stevens HE, Smith KM, Rash BG, Vaccarino FM. Neural stem cell regulation, fibroblast growth factors, and the developmental origins of neuropsychiatric disorders. Front Neurosci 2010; 4. [PMID: 20877431 PMCID: PMC2944667 DOI: 10.3389/fnins.2010.00059] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Accepted: 07/20/2010] [Indexed: 12/15/2022] Open
Abstract
There is increasing appreciation for the neurodevelopmental underpinnings of many psychiatric disorders. Disorders that begin in childhood such as autism, language disorders or mental retardation as well as adult-onset mental disorders may have origins early in neurodevelopment. Neural stem cells (NSCs) can be defined as self-renewing, multipotent cells that are present in both the embryonic and adult brain. Several recent research findings demonstrate that psychiatric illness may begin with abnormal specification, growth, expansion and differentiation of embryonic NSCs. For example, candidate susceptibility genes for schizophrenia, autism and major depression include the signaling molecule Disrupted In Schizophrenia-1 (DISC-1), the homeodomain gene engrailed-2 (EN-2), and several receptor tyrosine kinases, including brain-derived growth factor and fibroblast growth factors, all of which have been shown to play important roles in NSCs or neuronal precursors. We will discuss here stem cell biology, signaling factors that affect these cells, and the potential contribution of these processes to the etiology of neuropsychiatric disorders. Hypotheses about how some of these factors relate to psychiatric disorders will be reviewed.
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Affiliation(s)
- Hanna E Stevens
- Yale Child Study Center, Yale University School of Medicine New Haven, CT, USA
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47
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Callan MA, Cabernard C, Heck J, Luois S, Doe CQ, Zarnescu DC. Fragile X protein controls neural stem cell proliferation in the Drosophila brain. Hum Mol Genet 2010; 19:3068-79. [PMID: 20504994 DOI: 10.1093/hmg/ddq213] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited mental retardation and is caused by the loss of function for Fragile X protein (FMRP), an RNA-binding protein thought to regulate synaptic plasticity by controlling the localization and translation of specific mRNAs. We have recently shown that FMRP is required to control the proliferation of the germline in Drosophila. To determine whether FMRP is also required for proliferation during brain development, we examined the distribution of cell cycle markers in dFmr1 brains compared with wild-type throughout larval development. Our results indicate that the loss of dFmr1 leads to a significant increase in the number of mitotic neuroblasts (NB) and BrdU incorporation in the brain, consistent with the notion that FMRP controls proliferation during neurogenesis. Developmental studies suggest that FMRP also inhibits neuroblast exit from quiescence in early larval brains, as indicated by misexpression of Cyclin E. Live imaging experiments indicate that by the third instar larval stage, the length of the cell cycle is unaffected, although more cells are found in S and G2/M in dFmr1 brains compared with wild-type. To determine the role of FMRP in neuroblast division and differentiation, we used Mosaic Analysis with a Repressible Marker (MARCM) approaches in the developing larval brain and found that single dFmr1 NB generate significantly more neurons than controls. Our results demonstrate that FMRP is required during brain development to control the exit from quiescence and proliferative capacity of NB as well as neuron production, which may provide insights into the autistic component of FXS.
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Affiliation(s)
- Matthew A Callan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA
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48
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Luo Y, Shan G, Guo W, Smrt RD, Johnson EB, Li X, Pfeiffer RL, Szulwach KE, Duan R, Barkho BZ, Li W, Liu C, Jin P, Zhao X. Fragile x mental retardation protein regulates proliferation and differentiation of adult neural stem/progenitor cells. PLoS Genet 2010; 6:e1000898. [PMID: 20386739 PMCID: PMC2851565 DOI: 10.1371/journal.pgen.1000898] [Citation(s) in RCA: 193] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 03/05/2010] [Indexed: 12/31/2022] Open
Abstract
Fragile X syndrome (FXS), the most common form of inherited mental retardation, is caused by the loss of functional fragile X mental retardation protein (FMRP). FMRP is an RNA–binding protein that can regulate the translation of specific mRNAs. Adult neurogenesis, a process considered important for neuroplasticity and memory, is regulated at multiple molecular levels. In this study, we investigated whether Fmrp deficiency affects adult neurogenesis. We show that in a mouse model of fragile X syndrome, adult neurogenesis is indeed altered. The loss of Fmrp increases the proliferation and alters the fate specification of adult neural progenitor/stem cells (aNPCs). We demonstrate that Fmrp regulates the protein expression of several components critical for aNPC function, including CDK4 and GSK3β. Dysregulation of GSK3β led to reduced Wnt signaling pathway activity, which altered the expression of neurogenin1 and the fate specification of aNPCs. These data unveil a novel regulatory role for Fmrp and translational regulation in adult neurogenesis. Fragile X syndrome, the most common cause of inherited mental retardation, results from the loss of functional Fragile X mental retardation protein (FMRP). FMRP is an RNA–binding protein and is known to bind to specific mRNAs and to regulate their translation both in vitro and in vivo. Adult neurogenesis, a process considered important for neuroplasticity and memory, is regulated at multiple molecular levels. Here we show that Fmrp could regulate the proliferation and fate specification of adult neural progenitor/stem cells (aNPCs). These data unveil a novel regulatory role for Fmrp in adult neurogenesis.
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Affiliation(s)
- Yuping Luo
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Ge Shan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Weixiang Guo
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Richard D. Smrt
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Eric B. Johnson
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Xuekun Li
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Rebecca L. Pfeiffer
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Keith E. Szulwach
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Ranhui Duan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Basam Z. Barkho
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Wendi Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Changmei Liu
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail: (XZ); (PJ)
| | - Xinyu Zhao
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
- * E-mail: (XZ); (PJ)
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49
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Bhattacharyya A, McMillan E, Chen SI, Wallace K, Svendsen CN. A critical period in cortical interneuron neurogenesis in down syndrome revealed by human neural progenitor cells. Dev Neurosci 2009; 31:497-510. [PMID: 19738365 DOI: 10.1159/000236899] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 05/30/2009] [Indexed: 12/11/2022] Open
Abstract
Down syndrome (DS) is a developmental disorder whose mental impairment is due to defective cortical development. Human neural progenitor cells (hNPCs) derived from fetal DS cortex initially produce normal numbers of neurons, but generate fewer neurons with time in culture, similar to the pattern of neurogenesis that occurs in DS in vivo. Microarray analysis of DS hNPCs at this critical time reveals gene changes indicative of defects in interneuron progenitor development. In addition, dysregulated expression of many genes involved in neural progenitor cell biology points to changes in the progenitor population and subsequent reduction in interneuron neurogenesis. Delineation of a critical period in interneuron development in DS provides a foundation for investigation of the basis of reduced neurogenesis in DS and defines a time when these progenitor cells may be amenable to therapeutic treatment.
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Affiliation(s)
- Anita Bhattacharyya
- Stem Cell Research Group, The Waisman Center, University of Wisconsin, Madison, Wisc. 53705, USA.
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50
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Eadie BD, Zhang WN, Boehme F, Gil-Mohapel J, Kainer L, Simpson JM, Christie BR. Fmr1 knockout mice show reduced anxiety and alterations in neurogenesis that are specific to the ventral dentate gyrus. Neurobiol Dis 2009; 36:361-73. [PMID: 19666116 DOI: 10.1016/j.nbd.2009.08.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 07/31/2009] [Accepted: 08/03/2009] [Indexed: 01/11/2023] Open
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by the selective loss of the expression of the Fmr1 gene. Key symptoms in FXS include intellectual impairment and abnormal anxiety-related behaviors. Fmr1 knockout (KO) mice exhibited reduced anxiety on two behavioral tests as well as a blunted corticosterone response to acute stress. Spatial learning and memory was not impaired when tested with both the classic Morris water and Plus-shaped mazes. Adult hippocampal neurogenesis has been associated with spatial learning and memory and emotions such as anxiety and depression. The process of neurogenesis appears abnormal in young adult Fmr1 KO mice, with significantly fewer bromodeoxyuridine-positive cells surviving for at least 4 weeks in the ventral subregion of the dentate gyrus (DG), a hippocampal subregion more closely associated with emotion than the dorsal DG. Within this smaller pool of surviving cells, we observed a concomitant increase in the proportion of surviving cells that acquire a neuronal phenotype. We did not observe a clear difference in cell proliferation using both endogenous and exogenous markers. This work indicates that loss of Fmr1 expression can alter anxiety-related behaviors in mice as well as produce region-specific alterations in hippocampal adult neurogenesis.
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Affiliation(s)
- B D Eadie
- MD/PhD Program, University of British Columbia, Vancouver, BC, Canada
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