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Regionalization of the Early Nervous System. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Aviña-Padilla K, Ramírez-Rafael JA, Herrera-Oropeza GE, Muley VY, Valdivia DI, Díaz-Valenzuela E, García-García A, Varela-Echavarría A, Hernández-Rosales M. Evolutionary Perspective and Expression Analysis of Intronless Genes Highlight the Conservation of Their Regulatory Role. Front Genet 2021; 12:654256. [PMID: 34306008 PMCID: PMC8302217 DOI: 10.3389/fgene.2021.654256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/01/2021] [Indexed: 11/13/2022] Open
Abstract
The structure of eukaryotic genes is generally a combination of exons interrupted by intragenic non-coding DNA regions (introns) removed by RNA splicing to generate the mature mRNA. A fraction of genes, however, comprise a single coding exon with introns in their untranslated regions or are intronless genes (IGs), lacking introns entirely. The latter code for essential proteins involved in development, growth, and cell proliferation and their expression has been proposed to be highly specialized for neuro-specific functions and linked to cancer, neuropathies, and developmental disorders. The abundant presence of introns in eukaryotic genomes is pivotal for the precise control of gene expression. Notwithstanding, IGs exempting splicing events entail a higher transcriptional fidelity, making them even more valuable for regulatory roles. This work aimed to infer the functional role and evolutionary history of IGs centered on the mouse genome. IGs consist of a subgroup of genes with one exon including coding genes, non-coding genes, and pseudogenes, which conform approximately 6% of a total of 21,527 genes. To understand their prevalence, biological relevance, and evolution, we identified and studied 1,116 IG functional proteins validating their differential expression in transcriptomic data of embryonic mouse telencephalon. Our results showed that overall expression levels of IGs are lower than those of MEGs. However, strongly up-regulated IGs include transcription factors (TFs) such as the class 3 of POU (HMG Box), Neurog1, Olig1, and BHLHe22, BHLHe23, among other essential genes including the β-cluster of protocadherins. Most striking was the finding that IG-encoded BHLH TFs fit the criteria to be classified as microproteins. Finally, predicted protein orthologs in other six genomes confirmed high conservation of IGs associated with regulating neural processes and with chromatin organization and epigenetic regulation in Vertebrata. Moreover, this study highlights that IGs are essential modulators of regulatory processes, such as the Wnt signaling pathway and biological processes as pivotal as sensory organ developing at a transcriptional and post-translational level. Overall, our results suggest that IG proteins have specialized, prevalent, and unique biological roles and that functional divergence between IGs and MEGs is likely to be the result of specific evolutionary constraints.
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Affiliation(s)
- Katia Aviña-Padilla
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Centro de Investigacioìn y de Estudios Avanzados del IPN, Unidad Irapuato, Guanajuato, Mexico
| | | | - Gabriel Emilio Herrera-Oropeza
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, United Kingdom
| | | | - Dulce I. Valdivia
- Centro de Investigacioìn y de Estudios Avanzados del IPN, Unidad Irapuato, Guanajuato, Mexico
| | - Erik Díaz-Valenzuela
- Centro de Investigacioìn y de Estudios Avanzados del IPN, Unidad Irapuato, Guanajuato, Mexico
| | - Andrés García-García
- Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro, Mexico
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Sepehrimanesh M, Ding B. Generation and optimization of highly pure motor neurons from human induced pluripotent stem cells via lentiviral delivery of transcription factors. Am J Physiol Cell Physiol 2020; 319:C771-C780. [PMID: 32783653 PMCID: PMC7654652 DOI: 10.1152/ajpcell.00279.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/21/2020] [Accepted: 08/05/2020] [Indexed: 12/11/2022]
Abstract
Generation of neurons from human induced pluripotent stem cells (hiPSCs) overcomes the limited access to human brain samples and greatly facilitates the progress of research in neurological diseases. However, it is still a challenge to generate a particular neuronal subtype with high purity and yield for determining the pathogenesis of diseased neurons using biochemical approaches. Motor neurons (MNs) are a specialized neuronal subtype responsible for governing both autonomic and volitional movement. Dysfunctions in MNs are implicated in a variety of movement diseases, such as amyotrophic lateral sclerosis (ALS). In this study, we generated functional MNs from human iPSCs via lentiviral delivery of transcription factors. Moreover, we optimized induction conditions by using different combinations of transcription factors and found that a single lentiviral vector expressing three factors [neurogenin-2 (NGN2), insulin gene enhancer 1 (ISL1), and LIM/homeobox 3 (LHX3)] is necessary and sufficient to induce iPSC-derived MNs (iPSC-MNs). These MNs robustly expressed general neuron markers [microtubule-associated protein 2 (MAP2), neurofilament protein (SMI-32), and tubulin β-3 class III (TUBB3)] and MN-specific markers [HB9 and choline acetyltransferase (ChAT)] and showed electrical maturation and firing of action potentials within 3 wk. This approach significantly improved the neuronal survival, yield, and purity, making it feasible to obtain abundant materials for biochemical studies in modeling movement diseases.
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Affiliation(s)
- Masood Sepehrimanesh
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana
| | - Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana
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Diotel N, Lübke L, Strähle U, Rastegar S. Common and Distinct Features of Adult Neurogenesis and Regeneration in the Telencephalon of Zebrafish and Mammals. Front Neurosci 2020; 14:568930. [PMID: 33071740 PMCID: PMC7538694 DOI: 10.3389/fnins.2020.568930] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022] Open
Abstract
In contrast to mammals, the adult zebrafish brain shows neurogenic activity in a multitude of niches present in almost all brain subdivisions. Irrespectively, constitutive neurogenesis in the adult zebrafish and mouse telencephalon share many similarities at the cellular and molecular level. However, upon injury during tissue repair, the situation is entirely different. In zebrafish, inflammation caused by traumatic brain injury or by induced neurodegeneration initiates specific and distinct neurogenic programs that, in combination with signaling pathways implicated in constitutive neurogenesis, quickly, and efficiently overcome the loss of neurons. In the mouse brain, injury-induced inflammation promotes gliosis leading to glial scar formation and inhibition of regeneration. A better understanding of the regenerative mechanisms occurring in the zebrafish brain could help to develop new therapies to combat the debilitating consequences of brain injury, stroke, and neurodegeneration. The aim of this review is to compare the properties of neural progenitors and the signaling pathways, which control adult neurogenesis and regeneration in the zebrafish and mammalian telencephalon.
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Affiliation(s)
- Nicolas Diotel
- INSERM, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, Saint-Denis, France
| | - Luisa Lübke
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Uwe Strähle
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Sepand Rastegar
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Jurisch-Yaksi N, Yaksi E, Kizil C. Radial glia in the zebrafish brain: Functional, structural, and physiological comparison with the mammalian glia. Glia 2020; 68:2451-2470. [PMID: 32476207 DOI: 10.1002/glia.23849] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/07/2020] [Accepted: 05/13/2020] [Indexed: 02/01/2023]
Abstract
The neuroscience community has witnessed a tremendous expansion of glia research. Glial cells are now on center stage with leading roles in the development, maturation, and physiology of brain circuits. Over the course of evolution, glia have highly diversified and include the radial glia, astroglia or astrocytes, microglia, oligodendrocytes, and ependymal cells, each having dedicated functions in the brain. The zebrafish, a small teleost fish, is no exception to this and recent evidences point to evolutionarily conserved roles for glia in the development and physiology of its nervous system. Due to its small size, transparency, and genetic amenability, the zebrafish has become an increasingly prominent animal model for brain research. It has enabled the study of neural circuits from individual cells to entire brains, with a precision unmatched in other vertebrate models. Moreover, its high neurogenic and regenerative potential has attracted a lot of attention from the research community focusing on neural stem cells and neurodegenerative diseases. Hence, studies using zebrafish have the potential to provide fundamental insights about brain development and function, and also elucidate neural and molecular mechanisms of neurological diseases. We will discuss here recent discoveries on the diverse roles of radial glia and astroglia in neurogenesis, in modulating neuronal activity and in regulating brain homeostasis at the brain barriers. By comparing insights made in various animal models, particularly mammals and zebrafish, our goal is to highlight the similarities and differences in glia biology among species, which could set new paradigms relevant to humans.
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Affiliation(s)
- Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Caghan Kizil
- German Center for Neurodegenerative Diseases (DZNE), Helmholtz Association, Dresden, Germany.,Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, Dresden, Germany
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Okolicsanyi RK, Oikari LE, Yu C, Griffiths LR, Haupt LM. Heparan Sulfate Proteoglycans as Drivers of Neural Progenitors Derived From Human Mesenchymal Stem Cells. Front Mol Neurosci 2018; 11:134. [PMID: 29740281 PMCID: PMC5928449 DOI: 10.3389/fnmol.2018.00134] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/03/2018] [Indexed: 01/19/2023] Open
Abstract
Background: Due to their relative ease of isolation and their high ex vivo and in vitro expansive potential, human mesenchymal stem cells (hMSCs) are an attractive candidate for therapeutic applications in the treatment of brain injury and neurological diseases. Heparan sulfate proteoglycans (HSPGs) are a family of ubiquitous proteins involved in a number of vital cellular processes including proliferation and stem cell lineage differentiation. Methods: Following the determination that hMSCs maintain neural potential throughout extended in vitro expansion, we examined the role of HSPGs in mediating the neural potential of hMSCs. hMSCs cultured in basal conditions (undifferentiated monolayer cultures) were found to co-express neural markers and HSPGs throughout expansion with modulation of the in vitro niche through the addition of exogenous HS influencing cellular HSPG and neural marker expression. Results: Conversion of hMSCs into hMSC Induced Neurospheres (hMSC IN) identified distinctly localized HSPG staining within the spheres along with altered gene expression of HSPG core protein and biosynthetic enzymes when compared to undifferentiated hMSCs. Conclusion: Comparison of markers of pluripotency, neural self-renewal and neural lineage specification between hMSC IN, hMSC and human neural stem cell (hNSC H9) cultures suggest that in vitro generated hMSC IN may represent an intermediary neurogenic cell type, similar to a common neural progenitor cell. In addition, this data demonstrates HSPGs and their biosynthesis machinery, are associated with hMSC IN formation. The identification of specific HSPGs driving hMSC lineage-specification will likely provide new markers to allow better use of hMSCs in therapeutic applications and improve our understanding of human neurogenesis.
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Affiliation(s)
- Rachel K Okolicsanyi
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Lotta E Oikari
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Chieh Yu
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Lyn R Griffiths
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Larisa M Haupt
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
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Liu X, Xia Y, Tang J, Ma L, Li C, Ma P, Mao B. Dual roles of Akirin2 protein during Xenopus neural development. J Biol Chem 2017; 292:5676-5684. [PMID: 28193841 DOI: 10.1074/jbc.m117.777110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/10/2017] [Indexed: 11/06/2022] Open
Abstract
To ensure correct spatial and temporal patterning, embryos must maintain pluripotent cell populations and control when cells undergo commitment. The newly identified nucleoprotein Akirin has been shown to modulate the innate immune response through epigenetic regulation and to play important roles in other physiological processes, but its role in neural development remains unknown. Here we show that Akirin2 is required for neural development in Xenopus and that knockdown of Akirin2 expands the expression of the neural progenitor marker Sox2 and inhibits expression of the differentiated neuronal marker N-tubulin. Akirin2 acts antagonistically to Geminin, thus regulating Sox2 expression, and maintains the neural precursor state by participating in the Brg1/Brm-associated factor (BAF) complex mediated by BAF53a. Additionally, Akirin2 also modulates N-tubulin expression by acting upstream of neuronal differentiation 1 (NeuroD) and in parallel with neurogenin-related 1 (Ngnr1) during terminal neuronal differentiation. Thus, our results reveal a novel model in which Akirin2 precisely coordinates and temporally controls Xenopus neural development.
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Affiliation(s)
- Xiaoliang Liu
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and.,the Kunming College of Life Science, University of the Chinese Academy of Sciences, Kunming 650203, China
| | - Yingjie Xia
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
| | - Jixin Tang
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
| | - Li Ma
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
| | - Chaocui Li
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
| | - Pengcheng Ma
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
| | - Bingyu Mao
- From the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China and
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Generating Diverse Spinal Motor Neuron Subtypes from Human Pluripotent Stem Cells. Stem Cells Int 2015; 2016:1036974. [PMID: 26823667 PMCID: PMC4707335 DOI: 10.1155/2016/1036974] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 09/14/2015] [Indexed: 12/18/2022] Open
Abstract
Resolving the mechanisms underlying human neuronal diversification remains a major challenge in developmental and applied neurobiology. Motor neurons (MNs) represent a diverse pool of neuronal subtypes exhibiting differential vulnerability in different human neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). The ability to predictably manipulate MN subtype lineage restriction from human pluripotent stem cells (PSCs) will form the essential basis to establishing accurate, clinically relevant in vitro disease models. I first overview motor neuron developmental biology to provide some context for reviewing recent studies interrogating pathways that influence the generation of MN diversity. I conclude that motor neurogenesis from PSCs provides a powerful reductionist model system to gain insight into the developmental logic of MN subtype diversification and serves more broadly as a leading exemplar of potential strategies to resolve the molecular basis of neuronal subclass differentiation within the nervous system. These studies will in turn permit greater mechanistic understanding of differential MN subtype vulnerability using in vitro human disease models.
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Han X, Gui B, Xiong C, Zhao L, Liang J, Sun L, Yang X, Yu W, Si W, Yan R, Yi X, Zhang D, Li W, Li L, Yang J, Wang Y, Sun YE, Zhang D, Meng A, Shang Y. Destabilizing LSD1 by Jade-2 promotes neurogenesis: an antibraking system in neural development. Mol Cell 2014; 55:482-94. [PMID: 25018020 DOI: 10.1016/j.molcel.2014.06.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/24/2014] [Accepted: 05/15/2014] [Indexed: 12/12/2022]
Abstract
Histone H3K4 demethylase LSD1 plays an important role in stem cell biology, especially in the maintenance of the silencing of differentiation genes. However, how the function of LSD1 is regulated and the differentiation genes are derepressed are not understood. Here, we report that elimination of LSD1 promotes embryonic stem cell (ESC) differentiation toward neural lineage. We showed that the destabilization of LSD1 occurs posttranscriptionally via the ubiquitin-proteasome pathway by an E3 ubiquitin ligase, Jade-2. We demonstrated that Jade-2 is a major LSD1 negative regulator during neurogenesis in vitro and in vivo in both mouse developing cerebral cortices and zebra fish embryos. Apparently, Jade-2-mediated degradation of LSD1 acts as an antibraking system and serves as a quick adaptive mechanism for re-establishing epigenetic landscape without more laborious transcriptional regulations. As a potential anticancer strategy, Jade-2-mediated LSD1 degradation could potentially be used in neuroblastoma cells to induce differentiation toward postmitotic neurons.
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Affiliation(s)
- Xiao Han
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Bin Gui
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Cong Xiong
- State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Linnan Zhao
- Key Laboratory of Mental Health, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Jing Liang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Luyang Sun
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohan Yang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Wenhua Yu
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Wenzhe Si
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Ruorong Yan
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Xia Yi
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Di Zhang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Wanjin Li
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Lifang Li
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Jianguo Yang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Yan Wang
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Yi Eve Sun
- Translational Center for Stem Cell Research, Tongji Hospital, Stem Cell Research Center, Tongji University School of Medicine, Shanghai 200065, China; Departments of Psychiatry and Behavioral Sciences and Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Dai Zhang
- Key Laboratory of Mental Health, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Anming Meng
- State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yongfeng Shang
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China; 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China.
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Hardwick LJA, Ali FR, Azzarelli R, Philpott A. Cell cycle regulation of proliferation versus differentiation in the central nervous system. Cell Tissue Res 2014; 359:187-200. [PMID: 24859217 PMCID: PMC4284380 DOI: 10.1007/s00441-014-1895-8] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/10/2014] [Indexed: 01/07/2023]
Abstract
Formation of the central nervous system requires a period of extensive progenitor cell proliferation, accompanied or closely followed by differentiation; the balance between these two processes in various regions of the central nervous system gives rise to differential growth and cellular diversity. The correlation between cell cycle lengthening and differentiation has been reported across several types of cell lineage and from diverse model organisms, both in vivo and in vitro. Furthermore, different cell fates might be determined during different phases of the preceding cell cycle, indicating direct cell cycle influences on both early lineage commitment and terminal cell fate decisions. Significant advances have been made in the last decade and have revealed multi-directional interactions between the molecular machinery regulating the processes of cell proliferation and neuronal differentiation. Here, we first introduce the modes of proliferation in neural progenitor cells and summarise evidence linking cell cycle length and neuronal differentiation. Second, we describe the manner in which components of the cell cycle machinery can have additional and, sometimes, cell-cycle-independent roles in directly regulating neurogenesis. Finally, we discuss the way that differentiation factors, such as proneural bHLH proteins, can promote either progenitor maintenance or differentiation according to the cellular environment. These intricate connections contribute to precise coordination and the ultimate division versus differentiation decision.
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Affiliation(s)
- Laura J A Hardwick
- Department of Oncology, Hutchison/MRC Research Centre, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
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11
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Kim A, Zamora-Martinez ER, Edwards S, Mandyam CD. Structural reorganization of pyramidal neurons in the medial prefrontal cortex of alcohol dependent rats is associated with altered glial plasticity. Brain Struct Funct 2014; 220:1705-20. [PMID: 24667898 PMCID: PMC4177030 DOI: 10.1007/s00429-014-0755-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 03/10/2014] [Indexed: 12/22/2022]
Abstract
In rodents, chronic intermittent ethanol vapor exposure (CIE) produces alcohol dependence, alters the activity of pyramidal neurons and decreases the number of glial progenitors in the medial prefrontal cortex (mPFC). Adult male Wistar rats were exposed to CIE and were injected with mitotic markers to label and phenotype proliferating cells to test the hypothesis that CIE produces concurrent alterations in the structure of pyramidal neurons and the cell cycle kinetics and developmental stages of glial progenitors in the mPFC. Medial prefrontal cortical tissue was processed for Golgi-Cox staining, immunohistochemistry and Western blotting analysis. CIE increased dendritic arborization and spine densities within basal and apical dendrites of pyramidal neurons via aberrant reorganization of actin cytoskeleton-associated molecules. CIE concomitantly increased the expression of total NR2B subunits without affecting phosphorylation of NR2B at Tyr-1472 or levels of PSD-95. CIE reduced the length of S-phase of the cell cycle of glial progenitors and reduced proliferation and differentiation of progenitors into bHLH transcription factor Olig2-expressing premyelinating oligodendrocyte progenitor cells (OPCs). CIE also produced a corresponding hyperphosphorylation of Olig2, and reduced expression of myelin basic protein. Our findings demonstrate that CIE-induced alterations in OPCs and myelin-related proteins are associated with profound alterations in the structure of pyramidal neurons. In sum, our results not only provide evidence that alcohol dependence leads to pathological changes in the mPFC, which may in part define a cellular basis for cognitive impairments associated with alcoholism, but also show dependence-associated morphological changes in the PFC at the single neuron level.
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Affiliation(s)
- Airee Kim
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| | - Eva R. Zamora-Martinez
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| | - Scott Edwards
- Department of Physiology, Alcohol & Drug Abuse Center of Excellence, LSU Health Sciences Center, New Orleans, LA, USA
| | - Chitra D. Mandyam
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
- Skaggs School of Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
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12
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Rodríguez-Aznar E, Barrallo-Gimeno A, Nieto MA. Scratch2 prevents cell cycle re-entry by repressing miR-25 in postmitotic primary neurons. J Neurosci 2013; 33:5095-105. [PMID: 23516276 PMCID: PMC6704984 DOI: 10.1523/jneurosci.4459-12.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 01/02/2013] [Accepted: 01/30/2013] [Indexed: 01/25/2023] Open
Abstract
During the development of the nervous system the regulation of cell cycle, differentiation, and survival is tightly interlinked. Newly generated neurons must keep cell cycle components under strict control, as cell cycle re-entry leads to neuronal degeneration and death. However, despite their relevance, the mechanisms controlling this process remain largely unexplored. Here we show that Scratch2 is involved in the control of the cell cycle in neurons in the developing spinal cord of the zebrafish embryo. scratch2 knockdown induces postmitotic neurons to re-enter mitosis. Scratch2 prevents cell cycle re-entry by maintaining high levels of the cycle inhibitor p57 through the downregulation of miR-25. Thus, Scratch2 appears to safeguard the homeostasis of postmitotic primary neurons by preventing cell cycle re-entry.
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Affiliation(s)
| | | | - M. Angela Nieto
- Instituto de Neurociencias, CSIC-UMH, San Juan de Alicante 03550, Spain
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13
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Bartesaghi S, Salomoni P. Tumor suppressive pathways in the control of neurogenesis. Cell Mol Life Sci 2013; 70:581-97. [PMID: 22802124 PMCID: PMC11113109 DOI: 10.1007/s00018-012-1063-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/16/2012] [Accepted: 06/18/2012] [Indexed: 12/16/2022]
Abstract
The generation of specialized neural cells in the developing and postnatal central nervous system is a highly regulated process, whereby neural stem cells divide to generate committed neuronal progenitors, which then withdraw from the cell cycle and start to differentiate. Cell cycle checkpoints play a major role in regulating the balance between neural stem cell expansion and differentiation. Loss of tumor suppressors involved in checkpoint control can lead to dramatic alterations of neurogenesis, thus contributing to neoplastic transformation. Here we summarize and critically discuss the existing literature on the role of tumor suppressive pathways and their regulatory networks in the control of neurogenesis and transformation.
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Affiliation(s)
- Stefano Bartesaghi
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, 72 Huntley Street, London, WC1E 6DD UK
| | - Paolo Salomoni
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, 72 Huntley Street, London, WC1E 6DD UK
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Bibikov NG, Grigoriev DY, Nizamov SV. Some properties of auditory neuron’s model trained by firing caused by tones modulated by low-frequency noise. Biophysics (Nagoya-shi) 2013. [DOI: 10.1134/s000635091301003x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Lim S, Kaldis P. Loss of Cdk2 and Cdk4 induces a switch from proliferation to differentiation in neural stem cells. Stem Cells 2012; 30:1509-20. [PMID: 22532528 DOI: 10.1002/stem.1114] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During neurogenesis, cell cycle regulators play a pivotal role in ensuring proper proliferation, cell cycle exit, and differentiation of neural precursors. However, the precise role of cyclin-dependent kinases (Cdks) in these processes is not well understood. We generated Cdk2 and Cdk4 double knockout (DKO) mice and found a striking ablation of the intermediate zone and cortical plate in mouse embryonic brain. When neural stem cells (NSCs) were isolated and analyzed, DKO NSCs proliferated comparable to wild type as Cdk1 now binds to cyclin D1 and E1 and assumes the role vacated by the loss of Cdk2 and Cdk4 in phosphorylating Rb. Although compensation was sufficient for the maintenance of self-renewal and multilineage potential, DKO NSCs displayed an altered cell cycle profile and were more prone to neuronal differentiation. This was manifested in vivo as a marked reduction in S-phase length and an increased tendency for neurogenic divisions that prevented proper expansion of the basal progenitor pool. Our data thus demonstrate the induction of neurogenic divisions in the absence of critical mediators of G1/S transition-Cdk2 and Cdk4, and highlight their evolutionary importance in the determination of cortical thickness.
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Affiliation(s)
- Shuhui Lim
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Singapore
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16
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Terriente J, Gerety SS, Watanabe-Asaka T, Gonzalez-Quevedo R, Wilkinson DG. Signalling from hindbrain boundaries regulates neuronal clustering that patterns neurogenesis. Development 2012; 139:2978-87. [PMID: 22764046 DOI: 10.1242/dev.080135] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
During central nervous system development, neural progenitors are patterned to form discrete neurogenic and non-neurogenic zones. In the zebrafish hindbrain, neurogenesis is organised by Fgf20a emanating from neurons located at each segment centre that inhibits neuronal differentiation in adjacent progenitors. Here, we have identified a molecular mechanism that clusters fgf20a-expressing neurons in segment centres and uncovered a requirement for this positioning in the regulation of neurogenesis. Disruption of hindbrain boundary cell formation alters the organisation of fgf20a-expressing neurons, consistent with a role of chemorepulsion from boundaries. The semaphorins Sema3fb and Sema3gb, which are expressed by boundary cells, and their receptor Nrp2a are required for clustering of fgf20a-expressing neurons at segment centres. The dispersal of fgf20a-expressing neurons that occurs following the disruption of boundaries or of Sema3fb/Sema3gb signalling leads to reduced FGF target gene expression in progenitors and an increased number of differentiating neurons. Sema3 signalling from boundaries thus links hindbrain segmentation to the positioning of fgf20a-expressing neurons that regulates neurogenesis.
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Affiliation(s)
- Javier Terriente
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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17
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Mukhopadhyay P, Brock G, Webb C, Pisano MM, Greene RM. Strain-specific modifier genes governing craniofacial phenotypes. ACTA ACUST UNITED AC 2012; 94:162-75. [PMID: 22371338 DOI: 10.1002/bdra.22890] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 12/12/2011] [Accepted: 12/13/2011] [Indexed: 01/06/2023]
Abstract
BACKGROUND The presence of strain-specific modifier genes is known to modulate the phenotype and pathophysiology of mice harboring genetically engineered mutations. Thus, identification of genetic modifier genes is requisite to understanding control of phenotypic expression. c-Ski is a transcriptional regulator. Ski(-/-) mice on a C57BL6J (B6) background exhibit facial clefting, while Ski(-/-) mice on a 129P3 (129) background present with exencephaly. METHODS In the present study, oligonucleotide-based gene expression profiling was used to identify potential strain-specific modifier gene candidates present in wild type mice of B6 and 129 genetic backgrounds. Changes in gene expression were verified by TaqMan quantitative real-time PCR. RESULTS Steady-state levels of 89 genes demonstrated a significantly higher level of expression, and those of 68 genes demonstrated a significantly lower level of expression in the developing neural tubes from embryonic day (E) 8.5, B6 embryos when compared to expression levels in neural tubes derived from E 8.5, 129 embryos. CONCLUSIONS Based on the results from the current comparative microarray study, and taking into consideration a number of relevant published reports, several potential strain-specific gene candidates, likely to modify the craniofacial phenotypes in various knockout mouse models have been identified.
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Affiliation(s)
- Partha Mukhopadhyay
- University of Louisville Birth Defects Center, Department of Molecular, Cellular and Craniofacial Biology, ULSD, University of Louisville, Louisville, Kentucky 40292, USA
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18
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Voumvourakis KI, Antonelou RC, Kitsos DK, Stamboulis E, Tsiodras S. TGF-β/BMPs: crucial crossroad in neural autoimmune disorders. Neurochem Int 2011; 59:542-50. [PMID: 21718734 DOI: 10.1016/j.neuint.2011.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 05/15/2011] [Accepted: 06/05/2011] [Indexed: 01/12/2023]
Abstract
Transforming growth factor beta (TGF-β) has a crucial role in the differentiation of ectodermal cells to neural or epidermal precursors. TGF-β and bone morphogenetic protein molecules (BMPs) are involved in many developmental processes, including cell proliferation and differentiation, apoptosis, mitotic arrest and intercellular interactions during morphogenesis. Additionally, the failure of central thymic tolerance mechanisms, leading to T cells with a skewed autoreactive response, is being described as a contributor in inflammatory processes in autoimmune diseases such as multiple sclerosis. Since TGF-β and BMP proteins are crucial for the development of the neural system and the thymus, as well as for the differentiation of T cells, it is essential to further investigate their role in the pathophysiology of this disorder by using references from embryonic experimental research. Available literature in the TGF/BMP signalling cascade, mostly during embryonic development of the nervous system is being reviewed. An attempt is made to further elucidate a potential role of TGF/BMP signalling in the pathophysiology of MS. During demyelination, BMP signaling, through various molecular mechanisms, directs the development of the adult neural stem cell in the astrocyte rather than the oligodendrocyte direction, therefore inhibiting the repair process. Further understanding of the above relationships could lead to the development of potentially efficient therapies for MS in the future.
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Affiliation(s)
- Konstantine I Voumvourakis
- 2nd Department of Neurology, Attikon University Hospital, University of Athens Medical School, Athens, Greece
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Hämmerle B, Ulin E, Guimera J, Becker W, Guillemot F, Tejedor FJ. Transient expression of Mnb/Dyrk1a couples cell cycle exit and differentiation of neuronal precursors by inducing p27KIP1 expression and suppressing NOTCH signaling. Development 2011; 138:2543-54. [PMID: 21610031 PMCID: PMC3100710 DOI: 10.1242/dev.066167] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 11/20/2022]
Abstract
The decision of a neural precursor to stop dividing and begin its terminal differentiation at the correct place, and at the right time, is a crucial step in the generation of cell diversity in the nervous system. Here, we show that the Down's syndrome candidate gene (Mnb/Dyrk1a) is transiently expressed in prospective neurons of vertebrate CNS neuroepithelia. The gain of function (GoF) of Mnb/Dyrk1a induced proliferation arrest. Conversely, its loss of function (LoF) caused over proliferation and cell death. We found that MNB/DYRK1A is both necessary and sufficient to upregulate, at transcriptional level, the expression of the cyclin-dependent kinase inhibitor p27(KIP1) in the embryonic chick spinal cord and mouse telencephalon, supporting a regulatory role for MNB/DYRK1A in cell cycle exit of vertebrate CNS neurons. All these actions required the kinase activity of MNB/DYRK1A. We also observed that MNB/DYRK1A is co-expressed with the NOTCH ligand Delta1 in single neuronal precursors. Furthermore, we found that MNB/DYRK1A suppressed NOTCH signaling, counteracted the pro-proliferative action of the NOTCH intracellular domain (NICD), stimulated Delta1 expression and was required for the neuronal differentiation induced by the decrease in NOTCH signaling. Nevertheless, although Mnb/Dyrk1a GoF led to extensive withdrawal of neuronal precursors from the cell cycle, it was insufficient to elicit their differentiation. Remarkably, a transient (ON/OFF) Mnb/Dyrk1a GoF efficiently induced neuronal differentiation. We propose that the transient expression of MNB/DYRK1A in neuronal precursors acts as a binary switch, coupling the end of proliferation and the initiation of neuronal differentiation by upregulating p27KIP1 expression and suppressing NOTCH signaling.
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Affiliation(s)
- Barbara Hämmerle
- Instituto de Neurociencias, CSIC and Universidad Miguel Hernandez, Alicante 03550, Spain
| | - Edgar Ulin
- Instituto de Neurociencias, CSIC and Universidad Miguel Hernandez, Alicante 03550, Spain
| | - Jordi Guimera
- HMGU-Institute of Developmental Genetics, 85764 Munich, Germany
| | - Walter Becker
- Institute of Pharmacology and Toxicology, RWTH Aachen University, 52057 Aachen, Germany
| | - François Guillemot
- Division of Molecular Neurobiology, National Institute for Medical Research, London NW7 1AA, UK
| | - Francisco J. Tejedor
- Instituto de Neurociencias, CSIC and Universidad Miguel Hernandez, Alicante 03550, Spain
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20
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Webb KJ, Coolen M, Gloeckner CJ, Stigloher C, Bahn B, Topp S, Ueffing M, Bally-Cuif L. The Enhancer of split transcription factor Her8a is a novel dimerisation partner for Her3 that controls anterior hindbrain neurogenesis in zebrafish. BMC DEVELOPMENTAL BIOLOGY 2011; 11:27. [PMID: 21586122 PMCID: PMC3125270 DOI: 10.1186/1471-213x-11-27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 05/17/2011] [Indexed: 12/31/2022]
Abstract
Background Neurogenesis control and the prevention of premature differentiation in the vertebrate embryo are crucial processes, allowing the formation of late-born cell types and ensuring the correct shape and cytoarchitecture of the brain. Members of the Hairy/Enhancer of Split (Hairy/E(spl)) family of bHLH-Orange transcription factors, such as zebrafish Her3, 5, 9 and 11, are implicated in the local inhibition of neurogenesis to maintain progenitor pools within the early neural plate. To better understand how these factors exert their inhibitory function, we aimed to isolate some of their functional interactors. Results We used a yeast two-hybrid screen with Her5 as bait and recovered a novel zebrafish Hairy/E(spl) factor - Her8a. Using phylogenetic and synteny analyses, we demonstrate that her8a evolved from an ancient duplicate of Hes6 that was recently lost in the mammalian lineage. We show that her8a is expressed across the mid- and anterior hindbrain from the start of segmentation. Through knockdown and misexpression experiments, we demonstrate that Her8a is a negative regulator of neurogenesis and plays an essential role in generating progenitor pools within rhombomeres 2 and 4 - a role resembling that of Her3. Her8a co-purifies with Her3, suggesting that Her8a-Her3 heterodimers may be relevant in this domain of the neural plate, where both proteins are co-expressed. Finally, we demonstrate that her8a expression is independent of Notch signaling at the early neural plate stage but that SoxB factors play a role in its expression, linking patterning information to neurogenesis control. Overall, the regulation and function of Her8a differ strikingly from those of its closest relative in other vertebrates - the Hes6-like proteins. Conclusions Our results characterize the phylogeny, expression and functional interactions involving a new Her factor, Her8a, and highlight the complex interplay of E(spl) proteins that generates the neurogenesis pattern of the zebrafish early neural plate.
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Affiliation(s)
- Katharine J Webb
- Zebrafish Neurogenetics Department, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr, 1, D-85764 Neuherberg, Germany.
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21
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In vivo Atoh1 targetome reveals how a proneural transcription factor regulates cerebellar development. Proc Natl Acad Sci U S A 2011; 108:3288-93. [PMID: 21300888 DOI: 10.1073/pnas.1100230108] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The proneural, basic helix-loop-helix transcription factor Atoh1 governs the development of numerous key neuronal subtypes, such as cerebellar granule and brainstem neurons, inner ear hair cells, and several neurons of the proprioceptive system, as well as diverse nonneuronal cell types, such as Merkel cells and intestinal secretory lineages. However, the mere handful of targets that have been identified barely begin to account for Atoh1's astonishing range of functions, which also encompasses seemingly paradoxical activities, such as promoting cell proliferation and medulloblastoma formation in the cerebellum and inducing cell cycle exit and suppressing tumorigenesis in the intestine. We used a multipronged approach to create a comprehensive, unbiased list of over 600 direct Atoh1 target genes in the postnatal cerebellum. We found that Atoh1 binds to a 10 nucleotide motif (AtEAM) to directly regulate genes involved in migration, cell adhesion, metabolism, and other previously unsuspected functions. This study expands current thinking about the transcriptional activities driving neuronal differentiation and provides a framework for further neurodevelopmental studies.
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22
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Elkouris M, Balaskas N, Poulou M, Politis PK, Panayiotou E, Malas S, Thomaidou D, Remboutsika E. Sox1 Maintains the Undifferentiated State of Cortical Neural Progenitor Cells via the Suppression of Prox1-Mediated Cell Cycle Exit and Neurogenesis. Stem Cells 2011; 29:89-98. [DOI: 10.1002/stem.554] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Salomoni P, Calegari F. Cell cycle control of mammalian neural stem cells: putting a speed limit on G1. Trends Cell Biol 2010; 20:233-43. [PMID: 20153966 DOI: 10.1016/j.tcb.2010.01.006] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 01/13/2010] [Accepted: 01/13/2010] [Indexed: 01/06/2023]
Abstract
The potential to increase unlimitedly in number and to generate differentiated cell types is a key feature of somatic stem cells. Within the nervous system, cellular and environmental determinants tightly control the expansion and differentiation of neural stem cells. Importantly, a number of studies have indicated that changes in cell cycle length can influence development and physiopathology of the nervous system, and might have played a role during evolution of the mammalian brain. Specifically, it has been suggested that the length of G1 can directly influence the differentiation of neural precursors. This has prompted the proposal of a model to explain how manipulation of G1 length can be used to expand neural stem cells. If validated in non-neural systems, this model might provide the means to control the proliferation vs. differentiation of somatic stem cells, which will represent a significant advance in the field.
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Affiliation(s)
- Paolo Salomoni
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, 72 Huntley Street, London WC1E 6BT, UK.
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24
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Sobieszczuk DF, Poliakov A, Xu Q, Wilkinson DG. A feedback loop mediated by degradation of an inhibitor is required to initiate neuronal differentiation. Genes Dev 2010; 24:206-18. [PMID: 20080956 DOI: 10.1101/gad.554510] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neuronal differentiation is regulated by proneural genes that promote neurogenesis and inhibitory mechanisms that maintain progenitors. This raises the question of how the up-regulation of proneural genes required to initiate neurogenesis occurs in the presence of such inhibition. We carried out loss and gain of gene function, an interaction screen for binding partners, and biochemical analyses to uncover the regulation, developmental role, and mechanism of action of a ubiquitination adaptor protein, Btbd6a (BTB domain containing 6a). We find that the proneural gene neurog1 up-regulates btbd6a, which in turn is required for up-regulation of neurog1. Btbd6a is an adaptor for the Cul3 ubiquitin ligase complex, and we find that it binds to the transcriptional repressor Plzf (promyelocytic leukemia zinc finger). Btbd6a promotes the relocation of Plzf from nucleus to cytoplasm and targets Plzf for ubiquitination and degradation. plzfa is expressed widely in the neural epithelium; when overexpressed, it inhibits neurogenesis, and this inhibition is reversed by btbd6a. The antagonism of endogenous plzfa by btbd6a is required for neurogenesis, since the block in neuronal differentiation caused by btbd6a knockdown is alleviated by plzfa knockdown. These findings reveal a feedback loop mediated by degradation of an inhibitor that is essential for progenitors to undergo the transition to neuronal differentiation.
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Affiliation(s)
- Dorothy F Sobieszczuk
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, London NW7 1AA, United Kingdom
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25
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Pathania M, Yan LD, Bordey A. A symphony of signals conducts early and late stages of adult neurogenesis. Neuropharmacology 2010; 58:865-76. [PMID: 20097213 DOI: 10.1016/j.neuropharm.2010.01.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/15/2010] [Accepted: 01/15/2010] [Indexed: 02/06/2023]
Abstract
Neurogenesis is continually occurring in two regions within the mammalian central nervous system (CNS) and increasing evidence suggests that it is important for selective learning and memory. How this plasticity is maintained in isolated niches within mature networks has been extensively studied in recent years, and a large body of evidence has accumulated describing many different regulatory factors and points of regulation. In this review, we attempt to organize the current research by summarizing findings affecting early neurogenesis: during proliferation, fate commitment and migration, versus late neurogenesis: including dendritic development, synaptic integration, and survival. We discuss the roles of three different classes of factors regulating early and late phases of neurogenesis: intrinsic factors, extrinsic factors, and neurotransmitters. Finally, we suggest that neurotransmitters may act upstream from extracellular other factors and cell-intrinsic mechanisms by coupling network activity to the niche microenvironment and intracellular machinery to ultimately regulate neurogenesis.
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Affiliation(s)
- Manavendra Pathania
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520-8082, USA
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26
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Gonzalez-Quevedo R, Lee Y, Poss KD, Wilkinson DG. Neuronal regulation of the spatial patterning of neurogenesis. Dev Cell 2010; 18:136-47. [PMID: 20152184 PMCID: PMC2822724 DOI: 10.1016/j.devcel.2009.11.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 10/05/2009] [Accepted: 11/13/2009] [Indexed: 11/25/2022]
Abstract
Precise regulation of neurogenesis is achieved in specific regions of the vertebrate nervous system by formation of distinct neurogenic and nonneurogenic zones. We have investigated how neurogenesis becomes confined to zones adjacent to rhombomere boundaries in the zebrafish hindbrain. The nonneurogenic zone at segment centers comprises a distinct progenitor population that expresses fibroblast growth factor (fgfr) 2, erm, sox9b, and the retinoic acid degrading enzyme, cyp26b1. FGF receptor activation upregulates expression of these genes and inhibits neurogenesis in segment centers. Cyp26 activity is a key effector inhibiting neuronal differentiation, suggesting antagonistic interactions with retinoid signaling. We identify the critical FGF ligand, fgf20a, which is expressed by specific neurons located in the mantle region at the center of segments, adjacent to the nonneurogenic zone. Fgf20a mutants have ectopic neurogenesis and lack the segment center progenitor population. Our findings reveal how signaling from neurons induces formation of a nonneurogenic zone of neural progenitors.
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Affiliation(s)
- Rosa Gonzalez-Quevedo
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Yoonsung Lee
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kenneth D. Poss
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - David G. Wilkinson
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
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27
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Her6 regulates the neurogenetic gradient and neuronal identity in the thalamus. Proc Natl Acad Sci U S A 2009; 106:19895-900. [PMID: 19903880 DOI: 10.1073/pnas.0910894106] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
During vertebrate brain development, the onset of neuronal differentiation is under strict temporal control. In the mammalian thalamus and other brain regions, neurogenesis is regulated also in a spatially progressive manner referred to as a neurogenetic gradient, the underlying mechanism of which is unknown. Here we describe the existence of a neurogenetic gradient in the zebrafish thalamus and show that the progression of neurogenesis is controlled by dynamic expression of the bHLH repressor her6. Members of the Hes/Her family are known to regulate proneural genes, such as Neurogenin and Ascl. Here we find that Her6 determines not only the onset of neurogenesis but also the identity of thalamic neurons, marked by proneural and neurotransmitter gene expression: loss of Her6 leads to premature Neurogenin1-mediated genesis of glutamatergic (excitatory) neurons, whereas maintenance of Her6 leads to Ascl1-mediated production of GABAergic (inhibitory) neurons. Thus, the presence or absence of a single upstream regulator of proneural gene expression, Her6, leads to the establishment of discrete neuronal domains in the thalamus.
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28
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Lange C, Huttner WB, Calegari F. Cdk4/cyclinD1 overexpression in neural stem cells shortens G1, delays neurogenesis, and promotes the generation and expansion of basal progenitors. Cell Stem Cell 2009; 5:320-31. [PMID: 19733543 DOI: 10.1016/j.stem.2009.05.026] [Citation(s) in RCA: 433] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 04/23/2009] [Accepted: 05/29/2009] [Indexed: 11/16/2022]
Abstract
During mouse embryonic development, neural progenitors lengthen the G1 phase of the cell cycle and this has been suggested to be a cause, rather than a consequence, of neurogenesis. To investigate whether G1 lengthening alone may cause the switch of cortical progenitors from proliferation to neurogenesis, we manipulated the expression of cdk/cyclin complexes and found that cdk4/cyclinD1 overexpression prevents G1 lengthening without affecting cell growth, cleavage plane, or cell cycle synchrony with interkinetic nuclear migration. Specifically, overexpression of cdk4/cyclinD1 inhibited neurogenesis while increasing the generation and expansion of basal (intermediate) progenitors, resulting in a thicker subventricular zone and larger surface area of the postnatal cortex originating from cdk4/cyclinD1-transfected progenitors. Conversely, lengthening of G1 by cdk4/cyclinD1-RNAi displayed the opposite effects. Thus, G1 lengthening is necessary and sufficient to switch neural progenitors to neurogenesis, and overexpression of cdk4/cyclinD1 can be used to increase progenitor expansion and, perhaps, cortical surface area.
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Affiliation(s)
- Christian Lange
- DFG-Research Center and Cluster of Excellence for Regenerative Therapies Dresden (CRTD), Medical Faculty, Technische Universität Dresden c/o Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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29
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Ossipova O, Ezan J, Sokol SY. PAR-1 phosphorylates Mind bomb to promote vertebrate neurogenesis. Dev Cell 2009; 17:222-33. [PMID: 19686683 DOI: 10.1016/j.devcel.2009.06.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 04/04/2009] [Accepted: 06/17/2009] [Indexed: 12/25/2022]
Abstract
Generation of neurons in the vertebrate central nervous system requires a complex transcriptional regulatory network and signaling processes in polarized neuroepithelial progenitor cells. Here we demonstrate that neurogenesis in the Xenopus neural plate in vivo and mammalian neural progenitors in vitro involves intrinsic antagonistic activities of the polarity proteins PAR-1 and aPKC. Furthermore, we show that Mind bomb (Mib), a ubiquitin ligase that promotes Notch ligand trafficking and activity, is a crucial molecular substrate for PAR-1. The phosphorylation of Mib by PAR-1 results in Mib degradation, repression of Notch signaling, and stimulation of neuronal differentiation. These observations suggest a conserved mechanism for neuronal fate determination that might operate during asymmetric divisions of polarized neural progenitor cells.
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Affiliation(s)
- Olga Ossipova
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
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30
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Nilbratt M, Porras O, Marutle A, Hovatta O, Nordberg A. Neurotrophic factors promote cholinergic differentiation in human embryonic stem cell-derived neurons. J Cell Mol Med 2009; 14:1476-84. [PMID: 19799651 PMCID: PMC3829014 DOI: 10.1111/j.1582-4934.2009.00916.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Cholinergic neurotransmission is essential for many important functions in the brain, including cognitive mechanisms. Here we demonstrate that human embryonic stem (hES) cells differentiate into a population of neuronal cells that express the cholinergic enzyme choline acetyltransferase and homeobox proteins specifying neuronal progenitors of ventral telencephalic lineage. These differentiated cells express transcripts for cholinergic α3, α4 and α7 nicotinic acetylcholine (ACh) receptor subunits and for M1, M2 and M3 muscarinic acetylcholine receptor (mAChR) subtypes. Stimulation with brain-derived neurotrophic factor, neurotrophin-3, ciliary neurotrophic factor and nerve growth factor increases the proportion of cholinergic neurons. These cholinergic receptors also mediate ACh-evoked increase in cytosolic calcium levels, and this response was unaffected by extracellular calcium removal and was abolished by the mAChR antagonist scopolamine. Our findings demonstrate expression of functional cholinergic receptors on hES cell-derived neurons, which may provide a source of expandable cells to facilitate screening of novel cholinergic drugs and useful for evaluating cell transplantation in animal models of cholinergic dysfunction.
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Affiliation(s)
- Mats Nilbratt
- Karolinska Institutet, Karolinska University Hospital Huddinge, Department of Neurobiology, Care Sciences and Society, Stockholm, Sweden
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Ye W, Mairet-Coello G, Pasoreck E, Dicicco-Bloom E. Patterns of p57Kip2 expression in embryonic rat brain suggest roles in progenitor cell cycle exit and neuronal differentiation. Dev Neurobiol 2009; 69:1-21. [PMID: 18814313 DOI: 10.1002/dneu.20680] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In developing central nervous system, a variety of mechanisms couple cell cycle exit to differentiation during neurogenesis. The cyclin-dependent kinase (CDK) inhibitor p57Kip2 controls the transition from proliferation to differentiation in many tissues, but roles in developing brain remain uncertain. To characterize possible functions, we defined p57Kip2 protein expression in embryonic (E) day 12.5 to 20.5 rat brains using immunohistochemistry combined with markers of proliferation and differentiation. The p57Kip2 was localized primarily in cell nuclei and positive cells formed two distinct patterns including wide dispersion and laminar aggregation that were brain region-specific. From E12.5 to E16.5, p57Kip2 expression was detected mainly in ventricular zone (VZ) and/or mantle zone of hippocampus, septum, basal ganglia, thalamus, hypothalamus, midbrain, and spinal cord. After E18.5, p57Kip2 was detected in select regions undergoing differentiation. The p57Kip2 expression was also compared with regional transcription factors, including Ngn2, Nkx2.1, and Pax6. Time course studies performed in diencephalon showed that p57Kip2 immunoreactivity colocalized with BrdU at 8 hr in nuclei exhibiting the wide dispersion pattern, whereas colocalization in the laminar pattern occurred only later. Moreover, p57Kip2 frequently colocalized with neuronal marker, beta-III tubulin. Finally, we characterized relationships of p57Kip2 to CDK inhibitor p27Kip1: in proliferative regions, p57Kip2 expression preceded p27Kip1 as cells underwent differentiation, though the proteins colocalized in substantial numbers of cells, suggesting potentially related yet distinct functions of Cip/Kip family members during neurogenesis. Our observations that p57Kip2 exhibits nuclear expression as precursors exit the cell cycle and begin expressing neuronal characteristics suggests that the CDK inhibitor contributes to regulating the transition from proliferation to differentiation during brain development.
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Affiliation(s)
- Weizhen Ye
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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32
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Anjomshoa M, Karbalaie K, Mardani M, Razavi S, Tanhaei S, Nasr-Esfahani MH, Baharvand H. Generation of motor neurons by coculture of retinoic acid-pretreated embryonic stem cells with chicken notochords. Stem Cells Dev 2009; 18:259-67. [PMID: 18422402 DOI: 10.1089/scd.2008.0049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Understanding neuroectoderm formation and its subsequent diversification to functional neural subtypes remains elusive. We have shown here for the first time that embryonic stem cells (ESCs) can differentiate into neurons and motor neurons (MNs) by using a coculture embryonic notochord model in vitro. Mouse ESCs were induced to form neural precursors via timed exposure to retinoic acid (RA) using the 4-/4+ RA protocol. These cells were then cocultured with alginate bead-encapsulated notochords isolated from Hamburger and Hamilton stage 6-10 chick embryos. The use of notochord alone was not able to induce neural differentiation from ESCs, and, therefore, notochord does not possess neural inducing activity. Hence, the most successful neuronal cells and MN differentiation was only observed following the coculture of RA-pretreated ESCs with notochord. This resulted in a significantly greater number of cells expressing microtubule-associated protein-2 (MAP2), HB9, choline acetyltransferase (ChAT) and MN-specific genes. While further characterization of these differentiated cells will be essential before transplantation studies commence, these data illustrate the effectiveness of embryonic notochord coculture in providing valuable molecular cues for directed differentiation of ESCs toward an MN lineage.
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Affiliation(s)
- Maryam Anjomshoa
- Department of Stem Cells, Cell Science Research Center, Royan Institute, ACECR, Esfahan Campus, Esfahan, Iran
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33
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Coolen M, Bally-Cuif L. [A microRNA as a gatekeeper of the midbrain-hindbrain boundary]. Med Sci (Paris) 2009; 24:787-9. [PMID: 18950566 DOI: 10.1051/medsci/20082410787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Ninkovic J, Stigloher C, Lillesaar C, Bally-Cuif L. Gsk3beta/PKA and Gli1 regulate the maintenance of neural progenitors at the midbrain-hindbrain boundary in concert with E(Spl) factor activity. Development 2008; 135:3137-48. [PMID: 18725518 DOI: 10.1242/dev.020479] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neuronal production in the midbrain-hindbrain domain (MH) of the vertebrate embryonic neural tube depends on a progenitor pool called the ;intervening zone' (IZ), located at the midbrain-hindbrain boundary. The progressive recruitment of IZ progenitors along the mediolateral (future dorsoventral) axis prefigures the earlier maturation of the MH basal plate. It also correlates with a lower sensitivity of medial versus lateral IZ progenitors to the neurogenesis inhibition process that maintains the IZ pool. This role is performed in zebrafish by the E(Spl) factors Her5 and Her11, but the molecular cascades cooperating with Her5/11, and those accounting for their reduced effect in the medial IZ, remain unknown. We demonstrate here that the kinases Gsk3beta and cAMP-dependent protein kinase A (PKA) are novel determinants of IZ formation and cooperate with E(Spl) activity in a dose-dependent manner. Similar to E(Spl), we show that the activity of Gsk3beta/PKA is sensed differently by medial versus lateral IZ progenitors. Furthermore, we identify the transcription factor Gli1, expressed in medial IZ cells, as an antagonist of E(Spl) and Gsk3beta/PKA, and demonstrate that the neurogenesis-promoting activity of Gli1 accounts for the reduced sensitivity of medial IZ progenitors to neurogenesis inhibitors and their increased propensity to differentiate. We also show that the expression and activity of Gli1 in this process are, surprisingly, independent of Hedgehog signaling. Together, our results suggest a model in which the modulation of E(Spl) and Gsk3beta/PKA activities by Gli1 underlies the dynamic properties of IZ maintenance and recruitment.
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Affiliation(s)
- Jovica Ninkovic
- Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Department of Zebrafish Neurogenetics, Institute of Developmental Genetics, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany
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35
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Plastic responses to spinal cord injury. Behav Brain Res 2008; 192:114-23. [DOI: 10.1016/j.bbr.2008.02.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 02/12/2008] [Accepted: 02/13/2008] [Indexed: 12/26/2022]
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36
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Resende RR, Britto LRG, Ulrich H. Pharmacological properties of purinergic receptors and their effects on proliferation and induction of neuronal differentiation of P19 embryonal carcinoma cells. Int J Dev Neurosci 2008; 26:763-77. [PMID: 18675894 DOI: 10.1016/j.ijdevneu.2008.07.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/01/2008] [Accepted: 07/01/2008] [Indexed: 11/18/2022] Open
Abstract
We have used P19 embryonal carcinoma cells as in vitro model for early neurogenesis to study ionotropic P2X and metabotropic P2Y receptor-induced Ca(2+) transients and their participation in induction of proliferation and differentiation. In embryonic P19 cells, P2Y(1), P2Y(2) and P2X(4) receptors or P2X-heteromultimers with similar P2X(4) pharmacology were responsible for ATP and ATP analogue-induced Ca(2+) transients. In neuronal-differentiated cells, P2Y(2,) P2Y(6), P2X(2) and possibly P2X(2)/P2X(6) heteromeric receptors were the major mediators of the elevations in intracellular free calcium concentration [Ca(2+)](i). We have collected evidence for the involvement of metabotropic purinergic receptors in proliferation induction of undifferentiated and neural progenitor cells by using a BrdU-incorporation assay. ATP-, UTP-, ADP-, 2-MeS-ATP- and ADP-betaS-induced proliferation in P19 cells was mediated by P2Y(1) and P2Y(2) receptors as judged from pharmacological profiles of receptor responses. ATP-provoked acceleration of neuronal differentiation, determined by analysis of nestin and neuron-specific enolase gene and protein expression, also resulted from P2Y(1) and P2Y(2) receptor activation. Proliferation- and differentiation-induction involved the activation of inositol-trisphosphate sensitive intracellular Ca(2+) stores.
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Affiliation(s)
- R R Resende
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
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37
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Stigloher C, Chapouton P, Adolf B, Bally-Cuif L. Identification of neural progenitor pools by E(Spl) factors in the embryonic and adult brain. Brain Res Bull 2008; 75:266-73. [DOI: 10.1016/j.brainresbull.2007.10.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 10/17/2007] [Indexed: 11/26/2022]
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38
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Traverso EE, Cho MS, Wu CF, Sater AK, Larabell CA, Kloc M, Etkin LD. Disruption of the dynamic sub-cellular localization of the Xenopus tumorhead protein causes embryonic lethality at the early gastrula transition. Differentiation 2007; 75:947-56. [PMID: 17459085 DOI: 10.1111/j.1432-0436.2007.00179.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Xenopus laevis tumorhead (TH) protein, a positive regulator of cell proliferation during embryogenesis, shuttles from the cell periphery into the nucleus during embryogenesis. In these studies, we performed a detailed analysis of TH's subcellular localization pattern to characterize its dynamic behavior. We found that TH exhibits distinct patterns of localization in different germ layers. At the blastula stage, TH is present in the apical cell periphery of prospective mesodermal and ectodermal cells. At the gastrula stage, TH is distributed throughout the entire cytoplasm of prospective mesodermal and ectodermal cells, whereas it shows nuclear localization in presumptive endodermal cells. TH moves into the nucleus of mesodermal and ectodermal cells during the neurula and early tailbud stages. To understand if TH is regulated by changes in its subcellular localization, we used a TH mutant containing signals for farnesylation and palmitoylation to tether the protein to the plasma membrane. Ubiquitous overexpression of this mutant causes embryonic lethality at the early gastrula transition. Further examination using TUNEL assays indicated that wild-type TH overexpression induces apoptosis during gastrulation, and that this effect is exacerbated by the overexpression of the membrane-bound TH mutant. Taken together, our results suggest that changes in the sub-cellular localization of the TH protein are important for its function because blocking the nuclear translocation of overexpressed TH increases apoptosis and causes embryos to die. Our data also suggest that TH plays a role outside the nucleus when it is present at the cell periphery.
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Affiliation(s)
- Edwin E Traverso
- Department of Molecular Genetics, The University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA
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39
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Nat R, Nilbratt M, Narkilahti S, Winblad B, Hovatta O, Nordberg A. Neurogenic neuroepithelial and radial glial cells generated from six human embryonic stem cell lines in serum-free suspension and adherent cultures. Glia 2007; 55:385-99. [PMID: 17152062 DOI: 10.1002/glia.20463] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The great potential of human embryonic stem (hES) cells offers the opportunity both for studying basic developmental processes in vitro as well as for drug screening, modeling diseases, or future cell therapy. Defining protocols for the generation of human neural progenies represents a most important prerequisite. Here, we have used six hES cell lines to evaluate defined conditions for neural differentiation in suspension and adherent culture systems. Our protocol does not require fetal serum, feeder cells, or retinoic acid at any step, to induce neural fate decisions in hES cells. We monitored neurogenesis in differentiating cultures using morphological (including on-line follow up), immunocytochemical, and RT-PCR assays. For each hES cell line, in suspension or adherent culture, the same longitudinal progression of neural differentiation occurs. We showed the dynamic transitions from hES cells to neuroepithelial (NE) cells, to radial glial (RG) cells, and to neurons. Thus, 7 days after neural induction the majority of cells were NE, expressing nestin, Sox1, and Pax6. During neural proliferation and differentiation, NE cells transformed in RG cells, which acquired vimentin, BLBP, GLAST, and GFAP, proliferated and formed radial scaffolds. gamma-Aminobutyric acid (GABA)-positive and glutamate positive neurons, few oligodendrocyte progenitors and astrocytes were formed in our conditions and timing. Our system successfully generates human RG cells and could be an effective source for neuronal replacement, since RG cells predominantly generate neurons and provide them with support and guidance.
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Affiliation(s)
- Roxana Nat
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden
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40
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Jansen A, Lohmann H, Scharfe S, Sehlmeyer C, Deppe M, Knecht S. The association between scalp hair-whorl direction, handedness and hemispheric language dominance: is there a common genetic basis of lateralization? Neuroimage 2006; 35:853-61. [PMID: 17275334 DOI: 10.1016/j.neuroimage.2006.12.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 12/11/2006] [Accepted: 12/13/2006] [Indexed: 12/01/2022] Open
Abstract
The hemispheres of the human brain are functionally asymmetric. The left hemisphere tends to be dominant for language and superior in the control of manual dexterity. The mechanisms underlying these asymmetries are not known. Genetic as well as environmental factors are discussed. Recently, atypical anticlockwise hair-whorl direction has been related to an increased probability for non-right-handedness and atypical hemispheric language dominance. These findings are fascinating and important since hair-whorl direction is a structural marker of lateralization and could provide a readily observable anatomical clue to functional brain lateralization. Based on data on handedness and hair-whorl direction, Amar Klar proposed a genetic model ("random-recessive model") in that a single gene with two alleles controls both handedness and hair-whorl orientation (Klar, A.J.S., 2003. Human handedness and scalp hair-whorl direction develop from a common genetic mechanism. Genetics 165, 269-276). The present study was designed to further investigate the relationship between scalp hair-whorl direction with handedness and hemispheric language dominance. 1212 subjects were investigated for scalp hair-whorl direction and handedness. Additionally, we determined hemispheric language dominance (as assessed by a word generation task) in a subgroup of 212 subjects using functional transcranial Doppler sonography (fTCD). As for the single attributes - hair-whorl direction, handedness, and language dominance - we reproduced previously published results. However, we found no association between hair-whorl direction and either language dominance or handedness. These results strongly argue against a common genetic basis of handedness or language lateralization with scalp hair-whorl direction. Inspection of hair patterns will not help us to determine language dominance.
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Affiliation(s)
- Andreas Jansen
- Department of Neurology, University of Münster, Germany.
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41
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Choi CB, Cho YK, Prakash KVB, Jee BK, Han CW, Paik YK, Kim HY, Lee KH, Chung N, Rha HK. Analysis of neuron-like differentiation of human bone marrow mesenchymal stem cells. Biochem Biophys Res Commun 2006; 350:138-46. [PMID: 16997271 DOI: 10.1016/j.bbrc.2006.09.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2006] [Accepted: 09/04/2006] [Indexed: 10/24/2022]
Abstract
The objective of the study was to evaluate differentiation of human bone marrow mesenchymal stem cells into true or pseudo neurons after treating with chemical induction medium in vitro. The morphological changes were assessed using interference contrast microscopy. Immunocytochemistry and Western blotting were performed using neuronal markers. Further evaluation was conducted with proteomic profiling, DNA microarray analysis and the whole-cell patch clamp test. After three hours of treatment with chemical induction medium, nearly three-fourths of the hMSCs changed to cells with a neuronal phenotype. The results of immunocytochemistry and Western blotting showed a high expression of neuronal markers in these cells at 3 h which decreased at 24 h. The proteomics analysis showed no change of proteins related to neuronal differentiation. DNA microarray showed downregulation of neuron related genes. The patch clamp test was unable to demonstrate any similarity to true neurons. Our findings suggest that neuron-like cells derived from chemical induction of hMSCs are not the genuine neurons as they resemble true neurons phenotypically but are different in genotypic and electrophysiological characteristics.
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Affiliation(s)
- Chi Bong Choi
- Catholic Neuroscience Center, The Catholic University of Korea, Seoul, Republic of Korea
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42
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Diks SH, Bink RJ, van de Water S, Joore J, van Rooijen C, Verbeek FJ, den Hertog J, Peppelenbosch MP, Zivkovic D. The novel gene asb11: a regulator of the size of the neural progenitor compartment. ACTA ACUST UNITED AC 2006; 174:581-92. [PMID: 16893969 PMCID: PMC2064263 DOI: 10.1083/jcb.200601081] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
From a differential display designed to isolate genes that are down-regulated upon differentiation of the central nervous system in Danio rerio embryos, we isolated d-asb11 (ankyrin repeat and suppressor of cytokine signaling box–containing protein 11). Knockdown of the d-Asb11 protein altered the expression of neural precursor genes sox2 and sox3 and resulted in an initial relative increase in proneural cell numbers. This was reflected by neurogenin1 expansion followed by premature neuronal differentiation, as demonstrated by HuC labeling and resulting in reduced size of the definitive neuronal compartment. Forced misexpression of d-asb11 was capable of ectopically inducing sox2 while it diminished or entirely abolished neurogenesis. Overexpression of d-Asb11 in both a pluripotent and a neural-committed progenitor cell line resulted in the stimulus-induced inhibition of terminal neuronal differentiation and enhanced proliferation. We conclude that d-Asb11 is a novel regulator of the neuronal progenitor compartment size by maintaining the neural precursors in the proliferating undifferentiated state possibly through the control of SoxB1 transcription factors.
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Affiliation(s)
- Sander H Diks
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, NL-9713 AV Groningen, Netherlands
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43
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Camus A, Perea-Gomez A, Moreau A, Collignon J. Absence of Nodal signaling promotes precocious neural differentiation in the mouse embryo. Dev Biol 2006; 295:743-55. [PMID: 16678814 DOI: 10.1016/j.ydbio.2006.03.047] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Accepted: 03/31/2006] [Indexed: 12/25/2022]
Abstract
After implantation, mouse embryos deficient for the activity of the transforming growth factor-beta member Nodal fail to form both the mesoderm and the definitive endoderm. They also fail to specify the anterior visceral endoderm, a specialized signaling center which has been shown to be required for the establishment of anterior identity in the epiblast. Our study reveals that Nodal-/- epiblast cells nevertheless express prematurely and ectopically molecular markers specific of anterior fate. Our analysis shows that neural specification occurs and regional identities characteristic of the forebrain are established precociously in the Nodal-/- mutant with a sequential progression equivalent to that of wild-type embryo. When explanted and cultured in vitro, Nodal-/- epiblast cells readily differentiate into neurons. Genes normally transcribed in organizer-derived tissues, such as Gsc and Foxa2, are also expressed in Nodal-/- epiblast. The analysis of Nodal-/-;Gsc-/- compound mutant embryos shows that Gsc activity plays no critical role in the acquisition of forebrain characters by Nodal-deficient cells. This study suggests that the initial steps of neural specification and forebrain development may take place well before gastrulation in the mouse and highlights a possible role for Nodal, at pregastrula stages, in the inhibition of anterior and neural fate determination.
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Affiliation(s)
- Anne Camus
- Laboratoire de Développement des Vertébrés, Institut Jacques Monod UMR 7592 CNRS, Universités Paris 6 et 7, 2 place Jussieu, 75251 Paris, France.
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44
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Takamiya M, Campos-Ortega JA. Hedgehog signalling controls zebrafish neural keel morphogenesis via its level-dependent effects on neurogenesis. Dev Dyn 2006; 235:978-97. [PMID: 16502420 DOI: 10.1002/dvdy.20720] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We investigated the role of hedgehog (Hh) signalling on zebrafish neurulation, focusing on the intimate relationship between neurogenesis and morphogenesis during the neural keel stage. Through the analyses of Hh loss- and gain-of-function phenotypes, we found that Hh signalling controls the neural keel morphogenesis. To investigate underlying mechanisms, we examined cellular elongation polarity in the neural keel of Hh loss- and gain-of-function phenotypes and compared this with the deficient phenotype of a planar cell polarity (PCP) molecule, Trilobite/Strabismus. We found that Hh signalling controls cell elongation polarity of the neuroepithelium at least in part by means of PCP pathway; however, its effects are not strong enough per se to affect keel morphogenesis; instead Hh signalling mainly controls keel morphogenesis by means of affecting both medial and lateral neurogenesis. We devised a method for precise evaluation of neurogenesis in loss- and gain-of-Hh phenotypes that compensates for its delay caused by disturbed morphogenesis. We present a model that Hh signalling exerts level-dependent and binary-opposite effects on medial neurogenesis, whose modification to explain lateral neurogenesis reveals regional differences of underlying mechanisms between the two proneural domains. Such differences seem to be created in part by regional effector signalling; the effects of high Hh-signalling on medial neurogenesis can be reversed in accordance to medial Tri/Stbm level, in a polarity independent manner.
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Affiliation(s)
- Masanari Takamiya
- Institute of Developmental Biology, University of Cologne, Gyrhofstrasse 17, D-50923 Cologne, Germany.
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45
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Zhao Y, Wang H, Mazzone T. Identification of stem cells from human umbilical cord blood with embryonic and hematopoietic characteristics. Exp Cell Res 2006; 312:2454-64. [PMID: 16716296 DOI: 10.1016/j.yexcr.2006.04.008] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 04/04/2006] [Accepted: 04/15/2006] [Indexed: 01/06/2023]
Abstract
We identified stem cells from the umbilical cord blood, designated cord blood-stem cells (CB-SC). CB-SC displayed important embryonic stem (ES) cell characteristics including expression of ES-cell-specific molecular markers including transcription factors OCT-4 and Nanog, along with stage-specific embryonic antigen (SSEA)-3 and SSEA-4. CB-SC also expressed hematopoietic cell antigens including CD9, CD45 and CD117, but were negative for CD34. CB-SC displayed very low immunogenicity as indicated by expression of a very low level of major histocompatibility complex (MHC) antigens and failure to stimulate the proliferation of allogeneic lymphocytes. CB-SC could give rise to cells with endothelial-like and neuronal-like characteristics in vitro, as demonstrated by expression of lineage-associated markers. Notably, CB-SC could be stimulated to differentiate into functional insulin-producing cells in vivo and eliminated hyperglycemia after transplantation into a streptozotocin-induced diabetic mouse model. These findings may have significant potential to advance stem-cell-based therapeutics.
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Affiliation(s)
- Yong Zhao
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, IL 60612, USA.
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46
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Zimmermann H. Nucleotide signaling in nervous system development. Pflugers Arch 2006; 452:573-88. [PMID: 16639549 DOI: 10.1007/s00424-006-0067-4] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Accepted: 03/06/2006] [Indexed: 11/24/2022]
Abstract
The development of the nervous system requires complex series of cellular programming and intercellular communication events that lead from the early neural induction to the formation of a highly structured central and peripheral nervous system. Neurogenesis continuously takes place also in select regions of the adult mammalian brain. During the past years, a multiplicity of cellular control mechanisms has been identified, ranging from differential transcriptional mediators to inducers or inhibitors of cell specification or neurite outgrowth. While the identification of transcription factors typical for the stage-specific progression has been a topic of key interest for many years, less is known concerning the potential multiplicity of relevant intercellular signaling pathways and the fine tuning of epigenetic gene regulation. Nucleotide receptors can induce a multiplicity of cellular signaling pathways and are involved in multiple molecular interactions, thus opening the possibility of cross talk between several signaling pathways, including growth factors, cytokines, and extracellular matrix components. An increasing number of studies provides evidence for a role of nucleotide signaling in nervous system development. This includes progenitor cell proliferation, cell migration, neuronal and glial cellular interaction and differentiation, and synaptic network formation.
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Affiliation(s)
- Herbert Zimmermann
- Institut fuer Zellbiologie und Neurowissenschaft, Biozentrum der J.W. Goethe-Universitaet, Max-von-Lane-Str. 9, 60438, Frankfurt am Main, Germany.
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47
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Weber B, Hoppe C, Faber J, Axmacher N, Fliessbach K, Mormann F, Weis S, Ruhlmann J, Elger CE, Fernández G. Association between scalp hair-whorl direction and hemispheric language dominance. Neuroimage 2006; 30:539-43. [PMID: 16289721 DOI: 10.1016/j.neuroimage.2005.09.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 08/25/2005] [Accepted: 09/23/2005] [Indexed: 11/30/2022] Open
Abstract
Asymmetry is a common phenomenon in higher organisms. In humans, the cortical representation of language exhibits a high degree of asymmetry with a prevalence of about 90% of left hemispheric dominance, the underlying mechanisms of which are largely unknown. Another sign that exhibits a form of lateralization is the scalp hair-whorl direction, which is either clockwise or anti-clockwise. The scalp hair-whorl develops from the same germ layer as the nervous system, the ectoderm, between the 10th and 16th week in utero and has been shown to be associated with various neurodevelopmental disorders. Here, we use an established fMRI paradigm to examine the association of a solely biological marker of asymmetry, hair-whorl direction and language lateralization. We show that the mechanism that influences hair-whorl direction and handedness [Klar, A.J.S., 2003. Human handedness and scalp hair-whorl direction develop from a common genetic mechanism. Genetics 1651, 269-276.] also affects cerebral language dominance.
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Affiliation(s)
- Bernd Weber
- Department of Epileptology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany.
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48
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Mackay DR, Hu M, Li B, Rhéaume C, Dai X. The mouse Ovol2 gene is required for cranial neural tube development. Dev Biol 2006; 291:38-52. [PMID: 16423343 PMCID: PMC2891516 DOI: 10.1016/j.ydbio.2005.12.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 11/23/2005] [Accepted: 12/01/2005] [Indexed: 02/02/2023]
Abstract
The Ovo gene family encodes a group of evolutionarily conserved transcription factors and includes members that reside downstream of key developmental signaling pathways such as Wg/Wnt and BMP/TGF-beta. In the current study, we explore the function of Ovol2, one of three Ovo paralogues in mice. We report that Ovol2 is expressed during early-mid embryogenesis, particularly in the inner cell mass at E3.5, in epiblast at E6.5, and at later stages in ectodermally derived tissues such as the rostral surface (epidermal) ectoderm. Embryos in which Ovol2 is ablated exhibit lethality by E10.5, prior to which they display severe defects including an open cranial neural tube. The neural defects are associated with improper Shh expression in the underlying rostral axial mesoderm and localized changes of neural marker expression along the dorsoventral axis, as well as with expanded cranial neural tissue and reduced cranial surface ectoderm culminating in a lateral shift of the neuroectoderm/surface ectoderm border. We propose that these defects reflect the involvement of Ovol2 in independent processes such as regionalized gene expression and neural/non-neural ectodermal patterning. Additionally, we present evidence that Ovol2 is required for efficient migration and survival of neural crest cells that arise at the neuroectoderm/surface ectoderm border, but not for their initial formation. Collectively, our studies indicate that Ovol2 is a key regulator of neural development and reveal a previously unexplored role for Ovo genes in mammalian embryogenesis.
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Affiliation(s)
- Douglas R. Mackay
- Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA
| | - Ming Hu
- Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA
| | - Baoan Li
- Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA
| | - Catherine Rhéaume
- Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA
| | - Xing Dai
- Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA
- Developmental Biology Center, University of California, Irvine, CA 92697, USA
- Corresponding author. Department of Biological Chemistry, College of Medicine, D250 Med Sci I, University of California, Irvine, CA 92697-1700, USA. Fax: +1 949 824 2688. (X. Dai)
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49
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Abstract
During the development of the mammalian central nervous system, neural stem cells and their derivative progenitor cells generate neurons by asymmetric and symmetric divisions. The proliferation versus differentiation of these cells and the type of division are closely linked to their epithelial characteristics, notably, their apical-basal polarity and cell-cycle length. Here, we discuss how these features change during development from neuroepithelial to radial glial cells, and how this transition affects cell fate and neurogenesis.
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Affiliation(s)
- Magdalena Götz
- Institute for Stem Cell Research, GSF-National Research Center for Environment and Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg/Munich, Germany.
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Takada H, Hattori D, Kitayama A, Ueno N, Taira M. Identification of target genes for the Xenopus Hes-related protein XHR1, a prepattern factor specifying the midbrain-hindbrain boundary. Dev Biol 2005; 283:253-67. [PMID: 15935340 DOI: 10.1016/j.ydbio.2005.04.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Revised: 04/02/2005] [Accepted: 04/16/2005] [Indexed: 01/29/2023]
Abstract
The midbrain-hindbrain boundary (MHB) acts as a local organizer in the development of the CNS in vertebrates. Previously, we identified an MHB-specific bHLH-WRPW transcriptional repressor gene, Xenopus Hes-related 1 (XHR1), which is initially expressed in the presumptive MHB (pre-MHB) region at the early gastrula stage. To better understand the gene cascades involved in MHB formation, we investigated the genes downstream from XHR1 by differential screening using a Xenopus cDNA macroarray and a dexamethasone (DEX)-inducible, dominant-negative transcriptional activator construct of XHR1 (XHR1-VP16-GR). Among the newly identified candidate target genes of XHR1 were Enhancer of split-related genes (ESR1, ESR3/7, and ESR9) and Xenopus laevis cleavage 2 (XLCL2). XHR1-VP16-GR induced the expression of the ESR genes and XLCL2 as well as Xdelta1, Xngnr1, and XHR1 itself in the presence of DEX even after pretreatment with the protein synthesis inhibitor, cycloheximide. This suggests that these genes are direct targets of XHR1. XHR1-knockdown experiments with antisense morpholino oligos and ectopic expression of wild-type XHR1 revealed that XHR1 is necessary and sufficient to repress ESR genes in the pre-MHB region. Misexpression of the ESR genes in the pre-MHB region repressed the MHB marker gene, Pax2, suggesting that the repression of the ESR genes by XHR1 is at least partly required for the early development of the pre-MHB. Our data also show that XHR1 is not activated by Notch signaling, differing from ESR genes. Taken together, we propose a model in which XHR1 defines the pre-MHB region as a prepattern gene by repressing those possible direct target genes.
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Affiliation(s)
- Hitomi Takada
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan
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