1
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Thor S. Indirect neurogenesis in space and time. Nat Rev Neurosci 2024; 25:519-534. [PMID: 38951687 DOI: 10.1038/s41583-024-00833-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/03/2024]
Abstract
During central nervous system (CNS) development, neural progenitor cells (NPCs) generate neurons and glia in two different ways. In direct neurogenesis, daughter cells differentiate directly into neurons or glia, whereas in indirect neurogenesis, neurons or glia are generated after one or more daughter cell divisions. Intriguingly, indirect neurogenesis is not stochastically deployed and plays instructive roles during CNS development: increased generation of cells from specific lineages; increased generation of early or late-born cell types within a lineage; and increased cell diversification. Increased indirect neurogenesis might contribute to the anterior CNS expansion evident throughout the Bilateria and help to modify brain-region size without requiring increased NPC numbers or extended neurogenesis. Increased indirect neurogenesis could be an evolutionary driver of the gyrencephalic (that is, folded) cortex that emerged during mammalian evolution and might even have increased during hominid evolution. Thus, selection of indirect versus direct neurogenesis provides a powerful developmental and evolutionary instrument that drives not only the evolution of CNS complexity but also brain expansion and modulation of brain-region size, and thereby the evolution of increasingly advanced cognitive abilities. This Review describes indirect neurogenesis in several model species and humans, and highlights some of the molecular genetic mechanisms that control this important process.
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Affiliation(s)
- Stefan Thor
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
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2
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Kim CN, Shin D, Wang A, Nowakowski TJ. Spatiotemporal molecular dynamics of the developing human thalamus. Science 2023; 382:eadf9941. [PMID: 37824646 PMCID: PMC10758299 DOI: 10.1126/science.adf9941] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 09/15/2023] [Indexed: 10/14/2023]
Abstract
The thalamus plays a central coordinating role in the brain. Thalamic neurons are organized into spatially distinct nuclei, but the molecular architecture of thalamic development is poorly understood, especially in humans. To begin to delineate the molecular trajectories of cell fate specification and organization in the developing human thalamus, we used single-cell and multiplexed spatial transcriptomics. We show that molecularly defined thalamic neurons differentiate in the second trimester of human development and that these neurons organize into spatially and molecularly distinct nuclei. We identified major subtypes of glutamatergic neuron subtypes that are differentially enriched in anatomically distinct nuclei and six subtypes of γ-aminobutyric acid-mediated (GABAergic) neurons that are shared and distinct across thalamic nuclei.
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Affiliation(s)
- Chang N Kim
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
- Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - David Shin
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
- Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Albert Wang
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Tomasz J Nowakowski
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
- Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
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3
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Gao J, Lu Y, Luo Y, Duan X, Chen P, Zhang X, Wu X, Qiu M, Shen W. β-Catenin and SOX2 Interaction Regulate Visual Experience-Dependent Cell Homeostasis in the Developing Xenopus Thalamus. Int J Mol Sci 2023; 24:13593. [PMID: 37686400 PMCID: PMC10488257 DOI: 10.3390/ijms241713593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/19/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
In the vertebrate brain, sensory experience plays a crucial role in shaping thalamocortical connections for visual processing. However, it is still not clear how visual experience influences tissue homeostasis and neurogenesis in the developing thalamus. Here, we reported that the majority of SOX2-positive cells in the thalamus are differentiated neurons that receive visual inputs as early as stage 47 Xenopus. Visual deprivation (VD) for 2 days shifts the neurogenic balance toward proliferation at the expense of differentiation, which is accompanied by a reduction in nuclear-accumulated β-catenin in SOX2-positive neurons. The knockdown of β-catenin decreases the expression of SOX2 and increases the number of progenitor cells. Coimmunoprecipitation studies reveal the evolutionary conservation of strong interactions between β-catenin and SOX2. These findings indicate that β-catenin interacts with SOX2 to maintain homeostatic neurogenesis during thalamus development.
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Affiliation(s)
- Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
- College of Life and Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yufang Lu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Yuhao Luo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xinyi Duan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Peiyao Chen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xinyu Zhang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xiaohua Wu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Mengsheng Qiu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
- College of Life and Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
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4
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Hendricks E, Quihuis AM, Hung ST, Chang J, Dorjsuren N, Der B, Staats KA, Shi Y, Sta Maria NS, Jacobs RE, Ichida JK. The C9ORF72 repeat expansion alters neurodevelopment. Cell Rep 2023; 42:112983. [PMID: 37590144 PMCID: PMC10757587 DOI: 10.1016/j.celrep.2023.112983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 07/05/2023] [Accepted: 07/31/2023] [Indexed: 08/19/2023] Open
Abstract
Genetic mutations that cause adult-onset neurodegenerative diseases are often expressed during embryonic stages, but it is unclear whether they alter neurodevelopment and how this might influence disease onset. Here, we show that the most common cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), a repeat expansion in C9ORF72, restricts neural stem cell proliferation and reduces cortical and thalamic size in utero. Surprisingly, a repeat expansion-derived dipeptide repeat protein (DPR) not known to reduce neuronal viability plays a key role in impairing neurodevelopment. Pharmacologically mimicking the effects of the repeat expansion on neurodevelopment increases susceptibility of C9ORF72 mice to motor defects. Thus, the C9ORF72 repeat expansion stunts development of the brain regions prominently affected in C9ORF72 FTD/ALS patients.
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Affiliation(s)
- Eric Hendricks
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Alicia M Quihuis
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Shu-Ting Hung
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jonathan Chang
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Nomongo Dorjsuren
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Balint Der
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA
| | - Kim A Staats
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA
| | - Yingxiao Shi
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Naomi S Sta Maria
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Justin K Ichida
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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5
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Kim CN, Shin D, Wang A, Nowakowski TJ. Spatiotemporal molecular dynamics of the developing human thalamus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554174. [PMID: 37662287 PMCID: PMC10473600 DOI: 10.1101/2023.08.21.554174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The thalamus plays a central coordinating role in the brain. Thalamic neurons are organized into spatially-distinct nuclei, but the molecular architecture of thalamic development is poorly understood, especially in humans. To begin to delineate the molecular trajectories of cell fate specification and organization in the developing human thalamus, we used single cell and multiplexed spatial transcriptomics. Here we show that molecularly-defined thalamic neurons differentiate in the second trimester of human development, and that these neurons organize into spatially and molecularly distinct nuclei. We identify major subtypes of glutamatergic neuron subtypes that are differentially enriched in anatomically distinct nuclei. In addition, we identify six subtypes of GABAergic neurons that are shared and distinct across thalamic nuclei. One-Sentence Summary Single cell and spatial profiling of the developing thalamus in the first and second trimester yields molecular mechanisms of thalamic nuclei development.
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6
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Govek KW, Chen S, Sgourdou P, Yao Y, Woodhouse S, Chen T, Fuccillo MV, Epstein DJ, Camara PG. Developmental trajectories of thalamic progenitors revealed by single-cell transcriptome profiling and Shh perturbation. Cell Rep 2022; 41:111768. [PMID: 36476860 PMCID: PMC9880597 DOI: 10.1016/j.celrep.2022.111768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 10/06/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
The thalamus is the principal information hub of the vertebrate brain, with essential roles in sensory and motor information processing, attention, and memory. The complex array of thalamic nuclei develops from a restricted pool of neural progenitors. We apply longitudinal single-cell RNA sequencing and regional abrogation of Sonic hedgehog (Shh) to map the developmental trajectories of thalamic progenitors, intermediate progenitors, and post-mitotic neurons as they coalesce into distinct thalamic nuclei. These data reveal that the complex architecture of the thalamus is established early during embryonic brain development through the coordinated action of four cell differentiation lineages derived from Shh-dependent and -independent progenitors. We systematically characterize the gene expression programs that define these thalamic lineages across time and demonstrate how their disruption upon Shh depletion causes pronounced locomotor impairment resembling infantile Parkinson's disease. These results reveal key principles of thalamic development and provide mechanistic insights into neurodevelopmental disorders resulting from thalamic dysfunction.
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Affiliation(s)
- Kiya W. Govek
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Sixing Chen
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Paraskevi Sgourdou
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Yao Yao
- Department of Animal and Dairy Science, Regenerative Bioscience Center, University of Georgia, 425 River Road, Athens, GA 30602, USA
| | - Steven Woodhouse
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Tingfang Chen
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Marc V. Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Douglas J. Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,Correspondence: (D.J.E.), (P.G.C.)
| | - Pablo G. Camara
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA,Lead contact,Correspondence: (D.J.E.), (P.G.C.)
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7
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Thalamocortical axons regulate neurogenesis and laminar fates in the early sensory cortex. Proc Natl Acad Sci U S A 2022; 119:e2201355119. [PMID: 35613048 PMCID: PMC9295754 DOI: 10.1073/pnas.2201355119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
This study addresses how the cerebral cortex is partitioned into specialized areas during development. Although both early embryonic patterning and postnatal synaptic input from sensory thalamic nuclei are known to be critical, early roles of thalamic axons in area-specific regulation of cortical neurogenesis are poorly understood. We examined this by developing a genetic mouse model in which thalamocortical projections fail to properly form during embryogenesis, and found these axons are required not only for an enhanced production of superficial layer neurons but also for promoting the layer 4 cell fate, a hallmark of the primary sensory cortex. These findings provide a mechanism by which thalamocortical axons complement the intrinsic programs of neurogenesis and early fate specification. Area-specific axonal projections from the mammalian thalamus shape unique cellular organization in target areas in the adult neocortex. How these axons control neurogenesis and early neuronal fate specification is poorly understood. By using mutant mice lacking the majority of thalamocortical axons, we show that these axons are required for the production and specification of the proper number of layer 4 neurons in primary sensory areas by the neonatal stage. Part of these area-specific roles is played by the thalamus-derived molecule, VGF. Our work reveals that extrinsic cues from sensory thalamic projections have an early role in the formation of cortical cytoarchitecture by enhancing the production and specification of layer 4 neurons.
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8
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Romero-Morales AI, Gama V. Revealing the Impact of Mitochondrial Fitness During Early Neural Development Using Human Brain Organoids. Front Mol Neurosci 2022; 15:840265. [PMID: 35571368 PMCID: PMC9102998 DOI: 10.3389/fnmol.2022.840265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial homeostasis -including function, morphology, and inter-organelle communication- provides guidance to the intrinsic developmental programs of corticogenesis, while also being responsive to environmental and intercellular signals. Two- and three-dimensional platforms have become useful tools to interrogate the capacity of cells to generate neuronal and glia progeny in a background of metabolic dysregulation, but the mechanistic underpinnings underlying the role of mitochondria during human neurogenesis remain unexplored. Here we provide a concise overview of cortical development and the use of pluripotent stem cell models that have contributed to our understanding of mitochondrial and metabolic regulation of early human brain development. We finally discuss the effects of mitochondrial fitness dysregulation seen under stress conditions such as metabolic dysregulation, absence of developmental apoptosis, and hypoxia; and the avenues of research that can be explored with the use of brain organoids.
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Affiliation(s)
| | - Vivian Gama
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
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9
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Leung RF, George AM, Roussel EM, Faux MC, Wigle JT, Eisenstat DD. Genetic Regulation of Vertebrate Forebrain Development by Homeobox Genes. Front Neurosci 2022; 16:843794. [PMID: 35546872 PMCID: PMC9081933 DOI: 10.3389/fnins.2022.843794] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/14/2022] [Indexed: 01/19/2023] Open
Abstract
Forebrain development in vertebrates is regulated by transcription factors encoded by homeobox, bHLH and forkhead gene families throughout the progressive and overlapping stages of neural induction and patterning, regional specification and generation of neurons and glia from central nervous system (CNS) progenitor cells. Moreover, cell fate decisions, differentiation and migration of these committed CNS progenitors are controlled by the gene regulatory networks that are regulated by various homeodomain-containing transcription factors, including but not limited to those of the Pax (paired), Nkx, Otx (orthodenticle), Gsx/Gsh (genetic screened), and Dlx (distal-less) homeobox gene families. This comprehensive review outlines the integral role of key homeobox transcription factors and their target genes on forebrain development, focused primarily on the telencephalon. Furthermore, links of these transcription factors to human diseases, such as neurodevelopmental disorders and brain tumors are provided.
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Affiliation(s)
- Ryan F. Leung
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Ankita M. George
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Enola M. Roussel
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Maree C. Faux
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
| | - David D. Eisenstat
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
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10
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Cirnaru MD, Song S, Tshilenge KT, Corwin C, Mleczko J, Galicia Aguirre C, Benlhabib H, Bendl J, Apontes P, Fullard J, Creus-Muncunill J, Reyahi A, Nik AM, Carlsson P, Roussos P, Mooney SD, Ellerby LM, Ehrlich ME. Unbiased identification of novel transcription factors in striatal compartmentation and striosome maturation. eLife 2021; 10:e65979. [PMID: 34609283 PMCID: PMC8492065 DOI: 10.7554/elife.65979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 08/20/2021] [Indexed: 02/06/2023] Open
Abstract
Many diseases are linked to dysregulation of the striatum. Striatal function depends on neuronal compartmentation into striosomes and matrix. Striatal projection neurons are GABAergic medium spiny neurons (MSNs), subtyped by selective expression of receptors, neuropeptides, and other gene families. Neurogenesis of the striosome and matrix occurs in separate waves, but the factors regulating compartmentation and neuronal differentiation are largely unidentified. We performed RNA- and ATAC-seq on sorted striosome and matrix cells at postnatal day 3, using the Nr4a1-EGFP striosome reporter mouse. Focusing on the striosome, we validated the localization and/or role of Irx1, Foxf2, Olig2, and Stat1/2 in the developing striosome and the in vivo enhancer function of a striosome-specific open chromatin region 4.4 Kb downstream of Olig2. These data provide novel tools to dissect and manipulate the networks regulating MSN compartmentation and differentiation, including in human iPSC-derived striatal neurons for disease modeling and drug discovery.
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Affiliation(s)
- Maria-Daniela Cirnaru
- Department of Neurology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Sicheng Song
- Department of Biomedical Informatics and Medical Education, University of WashingtonSeattleUnited States
| | | | - Chuhyon Corwin
- Department of Neurology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Justyna Mleczko
- Department of Neurology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | | | - Houda Benlhabib
- Department of Biomedical Informatics and Medical Education, University of WashingtonSeattleUnited States
| | - Jaroslav Bendl
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Psychiatry, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Pasha Apontes
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Psychiatry, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - John Fullard
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Psychiatry, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Jordi Creus-Muncunill
- Department of Neurology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Azadeh Reyahi
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Ali M Nik
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Peter Carlsson
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburgSweden
| | - Panos Roussos
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Psychiatry, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Mental Illness Research, Education, and Clinical Center (VISN 2 South)BronxUnited States
| | - Sean D Mooney
- Department of Biomedical Informatics and Medical Education, University of WashingtonSeattleUnited States
| | | | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
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11
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Landy MA, Goyal M, Casey KM, Liu C, Lai HC. Loss of Prdm12 during development, but not in mature nociceptors, causes defects in pain sensation. Cell Rep 2021; 34:108913. [PMID: 33789102 PMCID: PMC8048104 DOI: 10.1016/j.celrep.2021.108913] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/11/2021] [Accepted: 03/05/2021] [Indexed: 12/30/2022] Open
Abstract
Prdm12 is a key transcription factor in nociceptor neurogenesis. Mutations of Prdm12 cause congenital insensitivity to pain (CIP) from failure of nociceptor development. However, precisely how deletion of Prdm12 during development or adulthood affects nociception is unknown. Here, we employ tissue- and temporal-specific knockout mouse models to test the function of Prdm12 during development and in adulthood. We find that constitutive loss of Prdm12 causes deficiencies in proliferation during sensory neurogenesis. We also demonstrate that conditional knockout from dorsal root ganglia (DRGs) during embryogenesis causes defects in nociception. In contrast, we find that, in adult DRGs, Prdm12 is dispensable for most pain-sensation and injury-induced hypersensitivity. Using transcriptomic analysis, we find mostly unique changes in adult Prdm12 knockout DRGs compared with embryonic knockout and that PRDM12 is likely a transcriptional activator in the adult. Overall, we find that the function of PRDM12 changes over developmental time.
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Affiliation(s)
- Mark A Landy
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Megan Goyal
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Katherine M Casey
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chen Liu
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Internal Medicine, Hypothalamic Research Center, Dallas, TX 75390, USA
| | - Helen C Lai
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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12
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The flavonoid 7,8-DHF fosters prenatal brain proliferation potency in a mouse model of Down syndrome. Sci Rep 2021; 11:6300. [PMID: 33737521 PMCID: PMC7973813 DOI: 10.1038/s41598-021-85284-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 02/24/2021] [Indexed: 12/17/2022] Open
Abstract
Neurogenesis impairment is a key determinant of intellectual disability in Down syndrome (DS), a genetic pathology due to triplication of chromosome 21. Since neurogenesis ceases after birth, apart in the hippocampus and olfactory bulb, the only means to tackle the problem of neurogenesis impairment in DS at its root is to intervene during gestation. A few studies in DS mouse models show that this is possible, although the drugs used may raise caveats in terms of safety. We previously found that neonatal treatment with 7,8-dihydroxyflavone (7,8-DHF), a flavonoid present in plants, restores hippocampal neurogenesis in the Ts65Dn model of DS. The goal of the current study was to establish whether prenatal treatment with 7,8-DHF improves/restores overall brain proliferation potency. Pregnant Ts65Dn females received 7,8-DHF from embryonic day 10 until delivery. On postnatal day 2 (P2) the pups were injected with BrdU and were killed after either 2 h or 52–60 days (P52–60). Evaluation of the number of proliferating (BrdU+) cells in various forebrain neurogenic niches of P2 mice showed that in treated Ts65Dn mice proliferation potency was improved or even restored in most of the examined regions, including the hippocampus. Quantification of the surviving BrdU+ cells in the dentate gyrus of P52–60 mice showed no difference between treated and untreated Ts65Dn mice. At P52–60, however, treated Ts65Dn mice exhibited a larger number of granule cells in comparison with their untreated counterparts, although their number did not reach that of euploid mice. Results show that 7,8-DHF has a widespread impact on prenatal proliferation potency in Ts65Dn mice and exerts mild long-term effects. It remains to be established whether treatment extending into the neonatal period can lead to an improvement in brain development that is retained in adulthood.
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13
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Neuroanatomical alterations in higher-order thalamic nuclei of fetuses with Down syndrome. Clin Neurol Neurosurg 2020; 194:105870. [PMID: 32480293 DOI: 10.1016/j.clineuro.2020.105870] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Down syndrome (DS) is a genetic condition characterized by cognitive disability starting from infancy. Children with DS exhibit deficits in several cognitive domains, including executive function, i.e., a set of cognitive processes that heavily depend on higher-order thalamic nuclei. The goal of this study was to establish whether executive function-related thalamic nuclei of fetuses with DS exhibit neuroanatomical alterations that may contribute to the defects in higher-order control processes seen in children with DS. PATIENTS AND METHODS In brain sections from fetuses with DS and control fetuses (gestational week 17-22), we evaluated the cellularity in the mediodorsal nucleus (MD), the centromedian nucleus (CM), and the parafascicular nucleus (PF) of the thalamus and the density of proliferating cells in the third ventricle. RESULTS We found that all three nuclei had a notably reduced cell density. This defect was associated with a reduced density of proliferating cells in the third ventricle, suggesting that the reduced cellularity in the MD, CM, and PF of fetuses with DS was due to neurogenesis impairment. The separate evaluation of projection neurons and interneurons in the MD, CM, and PF showed that in fetuses with DS the density of projection neurons was reduced, with no changes in interneuron density. CONCLUSION This study provides novel evidence for DS-linked cellularity alterations in the MD, CM, and PF and suggests that altered signal processing in these nuclei may be involved in the impairment in higher-order control processes observed in individuals with DS starting from infancy.
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14
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Tran H, Park W, Seong S, Jeong J, Nguyen Q, Yoon J, Baek K, Jeong Y. Tcf7l2
transcription factor is required for the maintenance, but not the initial specification, of the neurotransmitter identity in the caudal thalamus. Dev Dyn 2019; 249:646-655. [DOI: 10.1002/dvdy.146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/15/2019] [Accepted: 12/15/2019] [Indexed: 12/31/2022] Open
Affiliation(s)
- Hong‐Nhung Tran
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Wonbae Park
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Sojeong Seong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Ji‐eun Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Quy‐Hoai Nguyen
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Jaeseung Yoon
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Kwanghee Baek
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
| | - Yongsu Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of BiotechnologyKyung Hee University Yongin‐si Republic of Korea
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15
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Curt JR, Yaghmaeian Salmani B, Thor S. Anterior CNS expansion driven by brain transcription factors. eLife 2019; 8:45274. [PMID: 31271353 PMCID: PMC6634974 DOI: 10.7554/elife.45274] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/03/2019] [Indexed: 02/06/2023] Open
Abstract
During CNS development, there is prominent expansion of the anterior region, the brain. In Drosophila, anterior CNS expansion emerges from three rostral features: (1) increased progenitor cell generation, (2) extended progenitor cell proliferation, (3) more proliferative daughters. We find that tailless (mouse Nr2E1/Tlx), otp/Rx/hbn (Otp/Arx/Rax) and Doc1/2/3 (Tbx2/3/6) are important for brain progenitor generation. These genes, and earmuff (FezF1/2), are also important for subsequent progenitor and/or daughter cell proliferation in the brain. Brain TF co-misexpression can drive brain-profile proliferation in the nerve cord, and can reprogram developing wing discs into brain neural progenitors. Brain TF expression is promoted by the PRC2 complex, acting to keep the brain free of anti-proliferative and repressive action of Hox homeotic genes. Hence, anterior expansion of the Drosophila CNS is mediated by brain TF driven ‘super-generation’ of progenitors, as well as ‘hyper-proliferation’ of progenitor and daughter cells, promoted by PRC2-mediated repression of Hox activity.
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Affiliation(s)
- Jesús Rodriguez Curt
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| | | | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden.,School of Biomedical Sciences, University of Queensland, Saint Lucia, Australia
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16
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Nakagawa Y. Development of the thalamus: From early patterning to regulation of cortical functions. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2019; 8:e345. [PMID: 31034163 DOI: 10.1002/wdev.345] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 02/06/2023]
Abstract
The thalamus is a brain structure of the vertebrate diencephalon that plays a central role in regulating diverse functions of the cerebral cortex. In traditional view of vertebrate neuroanatomy, the thalamus includes three regions, dorsal thalamus, ventral thalamus, and epithalamus. Recent molecular embryological studies have redefined the thalamus and the associated axial nomenclature of the diencephalon in the context of forebrain patterning. This new view has provided a useful conceptual framework for studies on molecular mechanisms of patterning, neurogenesis and fate specification in the thalamus as well as the guidance mechanisms for thalamocortical axons. Additionally, the availability of genetic tools in mice has led to important findings on how thalamic development is linked to the development of other brain regions, particularly the cerebral cortex. This article will give an overview of the organization of the embryonic thalamus and how progenitor cells in the thalamus generate neurons that are organized into discrete nuclei. I will then discuss how thalamic development is orchestrated with the development of the cerebral cortex and other brain regions. This article is categorized under: Nervous System Development > Vertebrates: Regional Development Nervous System Development > Vertebrates: General Principles.
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Affiliation(s)
- Yasushi Nakagawa
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota
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17
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Guo Q, Li JYH. Defining developmental diversification of diencephalon neurons through single cell gene expression profiling. Development 2019; 146:dev.174284. [PMID: 30872278 DOI: 10.1242/dev.174284] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 03/07/2019] [Indexed: 12/31/2022]
Abstract
The embryonic diencephalon forms integration centers and relay stations in the forebrain. Anecdotal expression studies suggest that the diencephalon contains multiple developmental compartments and subdivisions. Here, we utilized single cell RNA sequencing to profile transcriptomes of dissociated cells from the diencephalon of E12.5 mouse embryos. We identified the divergence of different progenitors, intermediate progenitors, and emerging neurons. By mapping the identified cell groups to their spatial origins, we characterized the molecular features of cell types and cell states arising from various diencephalic domains. Furthermore, we reconstructed the developmental trajectory of distinct cell lineages, and thereby identified the genetic cascades and gene regulatory networks underlying the progression of the cell cycle, neurogenesis and cellular diversification. The analysis provides new insights into the molecular mechanisms underlying the amplification of intermediate progenitor cells in the thalamus. The single cell-resolved trajectories not only confirm a close relationship between the rostral thalamus and prethalamus, but also uncover an unexpected close relationship between the caudal thalamus, epithalamus and rostral pretectum. Our data provide a useful resource for systematic studies of cell heterogeneity and differentiation kinetics within the diencephalon.
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Affiliation(s)
- Qiuxia Guo
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - James Y H Li
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA .,Institute for Systems Genomics, University of Connecticut, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
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18
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Logan S, Jiang C, Yan Y, Inagaki Y, Arzua T, Bai X. Propofol Alters Long Non-Coding RNA Profiles in the Neonatal Mouse Hippocampus: Implication of Novel Mechanisms in Anesthetic-Induced Developmental Neurotoxicity. Cell Physiol Biochem 2018; 49:2496-2510. [PMID: 30261491 DOI: 10.1159/000493875] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 09/18/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Propofol induces acute neurotoxicity (e.g., neuroapoptosis) followed by impairment of long-term memory and learning in animals. However, underlying mechanisms remain largely unknown. Long non-coding RNAs (lncRNAs) are found to participate in various pathological processes. We hypothesized that lncRNA profile and the associated signaling pathways were altered, and these changes might be related to the neurotoxicity observed in the neonatal mouse hippocampus following propofol exposure. METHODS In this laboratory experiment, 7-day-old mice were exposed to a subanesthetic dose of propofol for 3 hours, with 4 animals per group. Hippocampal tissues were harvested 3 hours after propofol administration. Neuroapoptosis was analyzed based on caspase 3 activity using a colorimetric assay. A microarray was performed to investigate the profiles of 35,923 lncRNAs and 24,881 messenger RNAs (mRNAs). Representative differentially expressed lncRNAs and mRNAs were validated using reverse transcription quantitative polymerase chain reaction. All mRNAs dysregulated by propofol and the 50 top-ranked, significantly dysregulated lncRNAs were subject to bioinformatics analysis for exploring the potential mechanisms and signaling network of propofol-induced neurotoxicity. RESULTS Propofol induced neuroapoptosis in the hippocampus, with differential expression of 159 lncRNAs and 100 mRNAs (fold change ± 2.0, P< 0.05). Bioinformatics analysis demonstrated that these lncRNAs and their associated mRNAs might participate in neurodegenerative pathways (e.g., calcium handling, apoptosis, autophagy, and synaptogenesis). CONCLUSION This novel report emphasizes that propofol alters profiles of lncRNAs, mRNAs, and their cooperative signaling network, which provides novel insights into molecular mechanisms of anesthetic-induced developmental neurodegeneration and preventive targets against the neurotoxicity.
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Affiliation(s)
- Sarah Logan
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Congshan Jiang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Xi'an Jiaotong University Health Science Center, Xian, China
| | - Yasheng Yan
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Yasuyoshi Inagaki
- Department of Emergency Medicine, Nayoro City General Hospital, Nayoro, Japan
| | - Thiago Arzua
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Xiaowen Bai
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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19
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Wong SZH, Scott EP, Mu W, Guo X, Borgenheimer E, Freeman M, Ming GL, Wu QF, Song H, Nakagawa Y. In vivo clonal analysis reveals spatiotemporal regulation of thalamic nucleogenesis. PLoS Biol 2018; 16:e2005211. [PMID: 29684005 PMCID: PMC5933804 DOI: 10.1371/journal.pbio.2005211] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 05/03/2018] [Accepted: 03/27/2018] [Indexed: 01/05/2023] Open
Abstract
The thalamus, a crucial regulator of cortical functions, is composed of many nuclei arranged in a spatially complex pattern. Thalamic neurogenesis occurs over a short period during mammalian embryonic development. These features have hampered the effort to understand how regionalization, cell divisions, and fate specification are coordinated and produce a wide array of nuclei that exhibit distinct patterns of gene expression and functions. Here, we performed in vivo clonal analysis to track the divisions of individual progenitor cells and spatial allocation of their progeny in the developing mouse thalamus. Quantitative analysis of clone compositions revealed evidence for sequential generation of distinct sets of thalamic nuclei based on the location of the founder progenitor cells. Furthermore, we identified intermediate progenitor cells that produced neurons populating more than one thalamic nuclei, indicating a prolonged specification of nuclear fate. Our study reveals an organizational principle that governs the spatial and temporal progression of cell divisions and fate specification and provides a framework for studying cellular heterogeneity and connectivity in the mammalian thalamus. The thalamus—a brain structure commonly associated with relaying sensory information between cortex and other regions—is organized into many cell clusters called nuclei. Each thalamic nucleus is populated by neurons with distinct patterns of gene expression and connections to other brain regions and plays a distinct role in cortical functions. In this study, we performed an analysis of developing cells in the thalamus, using the mosaic analysis with double markers (MADM) method in mice, a technique that allows the labeling of descendants of dividing cells. Using 3 different transgenic mouse lines allowed us to determine the cell lineage of thalamic progenitor cells at different locations and stages of differentiation. By genetically labeling single progenitor cells, we measured how cell division and maturation occurs during the brief time span when neurons are generated. Our data also show how neurons eventually contribute to multiple nuclei across the thalamus. The organizational principles that we found in the thalamus might apply to the development of other brain structures that are composed of multiple nuclei.
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Affiliation(s)
- Samuel Z. H. Wong
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- The Cellular and Molecular Medicine Graduate Program, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Earl Parker Scott
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Wenhui Mu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xize Guo
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Ella Borgenheimer
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Madeline Freeman
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Guo-li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- The Cellular and Molecular Medicine Graduate Program, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Qing-Feng Wu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail: (Q-FW); (HS); (YN)
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- The Cellular and Molecular Medicine Graduate Program, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (Q-FW); (HS); (YN)
| | - Yasushi Nakagawa
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- * E-mail: (Q-FW); (HS); (YN)
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20
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Lee B, Lee M, Song S, Loi LD, Lam DT, Yoon J, Baek K, Curtis DJ, Jeong Y. Specification of neurotransmitter identity by Tal1 in thalamic nuclei. Dev Dyn 2017; 246:749-758. [PMID: 28685891 DOI: 10.1002/dvdy.24546] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/20/2017] [Accepted: 07/04/2017] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The neurons contributing to thalamic nuclei are derived from at least two distinct progenitor domains: the caudal (cTH) and rostral (rTH) populations of thalamic progenitors. These neural compartments exhibit unique neurogenic patterns, and the molecular mechanisms underlying the acquisition of neurotransmitter identity remain largely unclear. RESULTS T-cell acute lymphocytic leukemia protein 1 (Tal1) was expressed in the early postmitotic cells in the rTH domain, and its expression was maintained in mature thalamic neurons in the ventrolateral geniculate nucleus (vLG) and the intergeniculate leaflet (IGL). To investigate a role of Tal1 in thalamic development, we used a newly generated mouse line driving Cre-mediated recombination in the rTH domain. Conditional deletion of Tal1 did not alter regional patterning in the developing diencephalon. However, in the absence of Tal1, rTH-derived thalamic neurons failed to maintain their postmitotic neuronal features, including neurotransmitter profile. Tal1-deficient thalamic neurons lost their GABAergic markers such as Gad1, Npy, and Penk in IGL/vLG. These defects may be associated at least in part with down-regulation of Nkx2.2, which is known as a critical regulator of rTH-derived GABAergic neurons. CONCLUSIONS Our results demonstrate that Tal1 plays an essential role in regulating neurotransmitter phenotype in the developing thalamic nuclei. Developmental Dynamics 246:749-758, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Bumwhee Lee
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Myungsin Lee
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Somang Song
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Linh Duc Loi
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Duc Tri Lam
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Jaeseung Yoon
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - Kwanghee Baek
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
| | - David J Curtis
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Australia
| | - Yongsu Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si, Republic of Korea
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21
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Jabaudon D. Fate and freedom in developing neocortical circuits. Nat Commun 2017; 8:16042. [PMID: 28671189 PMCID: PMC5500875 DOI: 10.1038/ncomms16042] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/23/2017] [Indexed: 12/22/2022] Open
Abstract
The activity of neuronal circuits of the neocortex underlies our ability to perceive the world and interact with our environment. During development, these circuits emerge from dynamic interactions between cell-intrinsic, genetically determined programs and input/activity-dependent signals, which together shape these circuits into adulthood. Building on a large body of experimental work, several recent technological developments now allow us to interrogate these nature–nurture interactions with single gene/single input/single-cell resolution. Focusing on excitatory glutamatergic neurons, this review discusses the genetic and input-dependent mechanisms controlling how individual cortical neurons differentiate into specialized cells to assemble into stereotypical local circuits within global, large-scale networks.
Proper functioning of the neocortex – the center of higher-order brain functions – depends on the correct assembly of neocortical neural circuits during development. Here the author discusses how cell-intrinsic developmental programs and activity-dependent signals together shape the formation of neocortical circuits.
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Affiliation(s)
- Denis Jabaudon
- Department of Basic Neurosciences, Geneva University, 1 rue Michel Servet, 1211 Geneva, Switzerland.,Clinic of Neurology, Geneva University Hospital, 1 rue Michel Servet, 1211 Geneva, Switzerland.,Geneva Neurocenter, Geneva University, 1 rue Michel Servet, 1211 Geneva, Switzerland
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22
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Ontogenetic establishment of order-specific nuclear organization in the mammalian thalamus. Nat Neurosci 2017; 20:516-528. [PMID: 28250409 PMCID: PMC5374008 DOI: 10.1038/nn.4519] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 01/25/2017] [Indexed: 12/11/2022]
Abstract
The thalamus connects the cortex with other brain regions and supports sensory perception, movement, and cognitive function via numerous distinct nuclei. However, the mechanisms underlying the development and organization of diverse thalamic nuclei remain largely unknown. Here we report an intricate ontogenetic logic of mouse thalamic structures. Individual radial glial progenitors in the developing thalamus actively divide and produce a cohort of neuronal progeny that shows striking spatial configuration and nuclear occupation related to functionality. Whereas the anterior clonal cluster displays relatively more tangential dispersion and contributes predominantly to nuclei with cognitive functions, the medial ventral posterior clonal cluster forms prominent radial arrays and contributes mostly to nuclei with sensory- or motor-related activities. Moreover, the first-order and higher-order sensory and motor nuclei across different modalities are largely segregated clonally. Notably, sonic hedgehog signaling activity influences clonal spatial distribution. Our study reveals lineage relationship to be a critical regulator of nonlaminated thalamus development and organization.
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23
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Chen L, Liu Y, Lin QM, Xue L, Wang W, Xu JW. Electroacupuncture at Baihui (DU20) acupoint up-regulates mRNA expression of NeuroD molecules in the brains of newborn rats suffering in utero fetal distress. Neural Regen Res 2016; 11:604-9. [PMID: 27212921 PMCID: PMC4870917 DOI: 10.4103/1673-5374.180745] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
NeuroD plays a key regulatory effect on differentiation of neural stem cells into mature neurons in the brain. Thus, we assumed that electroacupuncture at Baihui (DU20) acupoint in newborn rats exposed to in utero fetal distress would influence expression of NeuroD. Electroacupuncture at Baihui was performed for 20 minutes on 3-day-old (Day 3) newborn Sprague-Dawley rats exposed to in utero fetal distress; electroacupuncture parameters consisted of sparse and dense waves at a frequency of 2–10 Hz. Real-time fluorescent quantitative PCR results demonstrated that mRNA expression of NeuroD, a molecule that indicates NeuroD, increased with prolonged time in brains of newborn rats, and peaked on Day 22. The level of mRNA expression was similar between Day 16 and Day 35. These findings suggest that electro acupuncture at Baihui acupoint could effectively increase mRNA expression of molecules involved in NeuroD in the brains of newborn rats exposed to in utero fetal distress.
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Affiliation(s)
- Lu Chen
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Yan Liu
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Qiao-Mei Lin
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Lan Xue
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Wei Wang
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Jian-Wen Xu
- Neurobiology Research Center, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China
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Mallika C, Guo Q, Li JYH. Gbx2 is essential for maintaining thalamic neuron identity and repressing habenular characters in the developing thalamus. Dev Biol 2015; 407:26-39. [PMID: 26297811 DOI: 10.1016/j.ydbio.2015.08.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/10/2015] [Accepted: 08/12/2015] [Indexed: 12/30/2022]
Abstract
The thalamus and habenula, two important nodes of the forebrain circuitry, are derived from a single developmental compartment, called prosomere 2, in the diencephalon. Habenular and thalamic neurons display distinct molecular identity, neurochemistry, and connectivity. Furthermore, their progenitors exhibit distinctive neurogenic patterns with a marked delay in the onset of neurogenesis in the thalamus. However, the progenitors in prosomere 2 express many common developmental regulators and the mechanism underlying the specification and differentiation of these two populations of neurons remains unknown. Gbx2, coding for a homeodomain transcription factor, is initially expressed in thalamic neuronal precursors that have just exited the cell cycle, and its expression is maintained in many mature thalamic neurons in adults. Deletion of Gbx2 severely disrupts histogenesis of the thalamus and abolishes thalamocortical projections in mice. Here, by using genome-wide transcriptional profiling, we show that Gbx2 promotes thalamic but inhibits habenular molecular characters. Remarkably, although Gbx2 is expressed in postmitotic neuronal precursors, deletion of Gbx2 changes gene expression and cell proliferation in dividing progenitors in the developing thalamus. These defects are partially rescued by the mosaic presence of wild-type cells, demonstrating a cell non-autonomous role of Gbx2 in regulating the development of thalamic progenitors. Our results suggest that Gbx2 is essential for the acquisition of the thalamic neuronal identity by repressing habenular identity through a feedback signaling from postmitotic neurons to progenitors.
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Affiliation(s)
- Chatterjee Mallika
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT 06030-6403, United States
| | - Qiuxia Guo
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT 06030-6403, United States
| | - James Y H Li
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT 06030-6403, United States.
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Song H, Lee B, Pyun D, Guimera J, Son Y, Yoon J, Baek K, Wurst W, Jeong Y. Ascl1 and Helt act combinatorially to specify thalamic neuronal identity by repressing Dlxs activation. Dev Biol 2015; 398:280-91. [DOI: 10.1016/j.ydbio.2014.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 12/02/2014] [Accepted: 12/04/2014] [Indexed: 11/25/2022]
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Lehigh KM, Leonard CE, Baranoski J, Donoghue MJ. Parcellation of the thalamus into distinct nuclei reflects EphA expression and function. Gene Expr Patterns 2013; 13:454-63. [PMID: 24036135 PMCID: PMC3839050 DOI: 10.1016/j.gep.2013.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 01/09/2023]
Abstract
Intercellular signaling via the Eph receptor tyrosine kinases and their ligands, the ephrins, acts to shape many regions of the developing brain. One intriguing consequence of Eph signaling is the control of mixing between discrete cell populations in the developing hindbrain, contributing to the formation of segregated rhombomeres. Since the thalamus is also a parcellated structure comprised of discrete nuclei, might Eph signaling play a parallel role in cell segregation in this brain structure? Analyses of expression reveal that several Eph family members are expressed in the forming thalamus and that cells expressing particular receptors form cellular groupings as development proceeds. Specifically, expression of receptors EphA4 or EphA7 and ligand ephrin-A5 is localized to distinct thalamic domains. EphA4 and EphA7 are often coexpressed in regions of the forming thalamus, with each receptor marking discrete thalamic domains. In contrast, ephrin-A5 is expressed by a limited group of thalamic cells. Within the ventral thalamus, EphA4 is present broadly, occasionally overlapping with ephrin-A5 expression. EphA7 is more restricted in its expression and is largely nonoverlapping with ephrin-A5. In mutant mice lacking one or both receptors or ephrin-A5, the appearance of the venteroposterolateral (VPL) and venteroposteromedial (VPM) nuclear complex is altered compared to wild type mice. These in vivo results support a role for Eph family members in the definition of the thalamic nuclei. In parallel, in vitro analysis reveals a hierarchy of mixing among cells expressing ephrin-A5 with cells expressing EphA4 alone, EphA4 and EphA7 together, or EphA7 alone. Together, these data support a model in which EphA molecules promote the parcellation of discrete thalamic nuclei by limiting the extent of cell mixing.
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Affiliation(s)
- Kathryn M. Lehigh
- Department of Biology, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
| | - Carrie E. Leonard
- Department of Biology, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
- Interdisciplinary Program in Neuroscience, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
| | - Jacob Baranoski
- Department of Biology, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
| | - Maria J. Donoghue
- Department of Biology, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
- Interdisciplinary Program in Neuroscience, Georgetown University, 410 Regents Hall, 37 and O St., NW, Washington, DC 20057
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The effect of chronic prenatal hypoxia on the development of mature neurons in the cerebellum. J Neurodev Disord 2013; 5:17. [PMID: 23822215 PMCID: PMC3706276 DOI: 10.1186/1866-1955-5-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 06/24/2013] [Indexed: 11/30/2022] Open
Abstract
Background Adverse intrauterine circumstances can result in abnormal brain development, and can contribute to many neurological disorders such as cerebral palsy and cognitive and behavioral deficits. These neurological problems are caused by conditions that cause chronic placental insufficiency (CPI), such as hypoxia and acidemia. Hypoxia has been implicated in structural alterations of the cerebellum during development; however, the changes to the cerebellar external granular layer (EGL) induced by chronic prenatal hypoxia are not well understood. We therefore investigated the effect of chronic prenatal hypoxia on the development of mature neurons in the EGL using the guinea pig CPI model. Methods Unilateral uterine artery ligation was performed at 30 to 32 days of gestation (dg) - with term defined as approximately 67 dg. At 50 dg, 60 dg, and one week after birth, fetuses and newborns were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. After fixation, dissection, and sectioning of cerebellar tissue from these animals, immunohistochemistry was performed with antibodies raised to hypoxia-induced factor 1α (Hif1α), Pax6, NeuroD, and NeuN. Results The induction of hypoxia was confirmed by the presence of Hif1α immunoreactivity in the EGL of the GR (but not control) fetuses. The only other cellular immunoreactivity found in any of the tissues was to the NeuN antibody, which is a marker of mature neurons. The proportion of NeuN-immunoreactive (NeuN-IR) cells to the total number of cells in the EGL did not differ between the GR and control groups at 50 and 60 dg. The density of NeuN-IR cells was greater in GR fetuses than in controls at 60 dg (P < 0.05) but not at 50 dg. At one week after birth, the EGL was just one cell thick, and only a few NeuN-IR cells could be observed in both groups. TUNEL assays performed to enable the evaluation of apoptosis in the cerebellar EGL revealed that cell death was not affected by hypoxia at 50 dg, 60 dg, and one week after birth. Conclusion These findings indicate that chronic prenatal hypoxia affects the process of neuronal production late in fetal life, but that this effect does not persist postnatally.
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Kikkawa T, Obayashi T, Takahashi M, Fukuzaki-Dohi U, Numayama-Tsuruta K, Osumi N. Dmrta1 regulates proneural gene expression downstream of Pax6 in the mammalian telencephalon. Genes Cells 2013; 18:636-49. [PMID: 23679989 DOI: 10.1111/gtc.12061] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 04/01/2013] [Indexed: 11/27/2022]
Abstract
The transcription factor Pax6 balances cell proliferation and neuronal differentiation in the mammalian developing neocortex by regulating the expression of target genes. Using microarray analysis, we observed the down-regulation of Dmrta1 (doublesex and mab-3-related transcription factor-like family A1) in the telencephalon of Pax6 homozygous mutant rats (rSey(2) /rSey(2) ). Dmrta1 expression was restricted to the neural stem/progenitor cells of the dorsal telencephalon. Overexpression of Dmrta1 induced the expression of the proneural gene Neurogenin2 (Neurog2) and conversely repressed Ascl1 (Mash1), a proneural gene expressed in the ventral telencephalon. We found that another Dmrt family molecule, Dmrt3, induced Neurog2 expression in the dorsal telencephalon. Our novel findings suggest that dual regulation of proneural genes mediated by Pax6 and Dmrt family members is crucial for cortical neurogenesis.
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Affiliation(s)
- Takako Kikkawa
- Division of Developmental Neuroscience, United Centers for Advanced Research and Translational Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
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Abstract
In primary sensory neocortical areas of mammals, the distribution of sensory receptors is mapped with topographic precision and amplification in proportion to the peripheral receptor density. The visual, somatosensory and auditory cortical maps are established during a critical period in development. Throughout this window in time, the developing cortical maps are vulnerable to deleterious effects of sense organ damage or sensory deprivation. The rodent barrel cortex offers an invaluable model system with which to investigate the mechanisms underlying the formation of topographic maps and their plasticity during development. Five rows of mystacial vibrissa (whisker) follicles on the snout and an array of sinus hairs are represented by layer IV neural modules ('barrels') and thalamocortical axon terminals in the primary somatosensory cortex. Perinatal damage to the whiskers or the sensory nerve innervating them irreversibly alters the structural organization of the barrels. Earlier studies emphasized the role of the sensory periphery in dictating whisker-specific brain maps and patterns. Recent advances in molecular genetics and analyses of genetically altered mice allow new insights into neural pattern formation in the neocortex and the mechanisms underlying critical period plasticity. Here, we review the development and patterning of the barrel cortex and the critical period plasticity.
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Affiliation(s)
- Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201-1075, USA.
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Bluske KK, Vue TY, Kawakami Y, Taketo MM, Yoshikawa K, Johnson JE, Nakagawa Y. β-Catenin signaling specifies progenitor cell identity in parallel with Shh signaling in the developing mammalian thalamus. Development 2012; 139:2692-702. [PMID: 22745311 DOI: 10.1242/dev.072314] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neural progenitor cells within the developing thalamus are spatially organized into distinct populations. Their correct specification is critical for generating appropriate neuronal subtypes in specific locations during development. Secreted signaling molecules, such as sonic hedgehog (Shh) and Wnts, are required for the initial formation of the thalamic primordium. Once thalamic identity is established and neurogenesis is initiated, Shh regulates the positional identity of thalamic progenitor cells. Although Wnt/β-catenin signaling also has differential activity within the thalamus during this stage of development, its significance has not been directly addressed. In this study, we used conditional gene manipulations in mice and explored the roles of β-catenin signaling in the regional identity of thalamic progenitor cells. We found β-catenin is required during thalamic neurogenesis to maintain thalamic fate while suppressing prethalamic fate, demonstrating that regulation of regional fate continues to require extrinsic signals. These roles of β-catenin appeared to be mediated at least partly by regulating two basic helix-loop-helix (bHLH) transcription factors, Neurog1 and Neurog2. β-Catenin and Shh signaling function in parallel to specify two progenitor domains within the thalamus, where individual transcription factors expressed in each progenitor domain were regulated differently by the two signaling pathways. We conclude that β-catenin has multiple functions during thalamic neurogenesis and that both Shh and β-catenin pathways are important for specifying distinct types of thalamic progenitor cells, ensuring that the appropriate neuronal subtypes are generated in the correct locations.
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Affiliation(s)
- Krista K Bluske
- Department of Neuroscience, Developmental Biology Center and Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
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Nakagawa Y, Shimogori T. Diversity of thalamic progenitor cells and postmitotic neurons. Eur J Neurosci 2012; 35:1554-62. [DOI: 10.1111/j.1460-9568.2012.08089.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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