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Banks E, Francis V, Lin SJ, Kharfallah F, Fonov V, Lévesque M, Han C, Kulasekaran G, Tuznik M, Bayati A, Al-Khater R, Alkuraya FS, Argyriou L, Babaei M, Bahlo M, Bakhshoodeh B, Barr E, Bartik L, Bassiony M, Bertrand M, Braun D, Buchert R, Budetta M, Cadieux-Dion M, Calame DG, Cope H, Cushing D, Efthymiou S, Elmaksoud MA, El Said HG, Froukh T, Gill HK, Gleeson JG, Gogoll L, Goh ESY, Gowda VK, Haack TB, Hashem MO, Hauser S, Hoffman TL, Hogue JS, Hosokawa A, Houlden H, Huang K, Huynh S, Karimiani EG, Kaulfuß S, Korenke GC, Kritzer A, Lee H, Lupski JR, Marco EJ, McWalter K, Minassian A, Minassian BA, Murphy D, Neira-Fresneda J, Northrup H, Nyaga DM, Oehl-Jaschkowitz B, Osmond M, Person R, Pehlivan D, Petree C, Sadleir LG, Saunders C, Schoels L, Shashi V, Spillmann RC, Srinivasan VM, Torbati PN, Tos T, Zaki MS, Zhou D, Zweier C, Trempe JF, Durcan TM, Gan-Or Z, Avoli M, Alves C, Varshney GK, Maroofian R, Rudko DA, McPherson PS. Loss of symmetric cell division of apical neural progenitors drives DENND5A-related developmental and epileptic encephalopathy. Nat Commun 2024; 15:7239. [PMID: 39174524 PMCID: PMC11341845 DOI: 10.1038/s41467-024-51310-z] [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: 08/09/2023] [Accepted: 07/23/2024] [Indexed: 08/24/2024] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) feature altered brain development, developmental delay and seizures, with seizures exacerbating developmental delay. Here we identify a cohort with biallelic variants in DENND5A, encoding a membrane trafficking protein, and develop animal models with phenotypes like the human syndrome. We demonstrate that DENND5A interacts with Pals1/MUPP1, components of the Crumbs apical polarity complex required for symmetrical division of neural progenitor cells. Human induced pluripotent stem cells lacking DENND5A fail to undergo symmetric cell division with an inherent propensity to differentiate into neurons. These phenotypes result from misalignment of the mitotic spindle in apical neural progenitors. Cells lacking DENND5A orient away from the proliferative apical domain surrounding the ventricles, biasing daughter cells towards a more fate-committed state, ultimately shortening the period of neurogenesis. This study provides a mechanism for DENND5A-related DEE that may be generalizable to other developmental conditions and provides variant-specific clinical information for physicians and families.
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Affiliation(s)
- Emily Banks
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Vincent Francis
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Sheng-Jia Lin
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Fares Kharfallah
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Vladimir Fonov
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Maxime Lévesque
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Chanshuai Han
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Gopinath Kulasekaran
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Marius Tuznik
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Armin Bayati
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | | | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Loukas Argyriou
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
| | - Meisam Babaei
- Department of Pediatrics, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Melanie Bahlo
- Walter and Eliza Hall Institute for Medical Research, Parkville, VIC, Australia
| | | | - Eileen Barr
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Lauren Bartik
- University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USA
- Department of Pediatrics, Division of Clinical Genetics, Children's Mercy Hospital, Kansas City, MO, USA
| | | | - Miriam Bertrand
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Dominique Braun
- Department of Human Genetics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Rebecca Buchert
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Mauro Budetta
- Paediatric and Child Neurology Unit, Cava de' Tirreni AOU S. Giovanni di Dio e Ruggiero d'Aragona Hospital, Salerno, Italy
| | - Maxime Cadieux-Dion
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA
| | - Daniel G Calame
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Heidi Cope
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Donna Cushing
- Laboratory Medicine and Genetics, Trillium Health Partners, Mississauga, ON, Canada
| | - Stephanie Efthymiou
- Department of Neuromuscular Diseases, University College London (UCL) Queen Square Institute of Neurology, London, UK
| | - Marwa Abd Elmaksoud
- Neurology Unit, Department of Pediatrics, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Huda G El Said
- Neurology Unit, Department of Pediatrics, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Tawfiq Froukh
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Harinder K Gill
- Provincial Medical Genetics Program at BC Women's Health Centre, Vancouver, BC, Canada
| | - Joseph G Gleeson
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Laura Gogoll
- Department of Human Genetics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Elaine S-Y Goh
- Laboratory Medicine and Genetics, Trillium Health Partners, Mississauga, ON, Canada
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Mais O Hashem
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Stefan Hauser
- German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
- Center for Neurology and Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, 72076, Germany
| | - Trevor L Hoffman
- Department of Regional Genetics, Southern California Kaiser Permanente Medical Group, Anaheim, CA, USA
| | | | - Akimoto Hosokawa
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Henry Houlden
- Department of Neuromuscular Diseases, University College London (UCL) Queen Square Institute of Neurology, London, UK
| | - Kevin Huang
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Stephanie Huynh
- Provincial Medical Genetics Program at BC Women's Health Centre, Vancouver, BC, Canada
| | - Ehsan G Karimiani
- Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, UK
- Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran
| | - Silke Kaulfuß
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
| | - G Christoph Korenke
- Department of Neuropediatrics, University Children's Hospital, Klinikum Oldenburg, Oldenburg, Germany
| | - Amy Kritzer
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Hane Lee
- 3billion Inc, Seoul, South Korea
| | - James R Lupski
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | | | | | - Arakel Minassian
- Centre for Applied Genomics, Genetics, and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - Berge A Minassian
- Department of Pediatrics and Neurology, UT Southwestern Medical Center, Dallas, TX, USA
| | - David Murphy
- Department of Clinical and Movement Neurosciences, University College London (UCL) Queen Square Institute of Neurology, London, UK
| | | | - Hope Northrup
- Department of Pediatrics, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Denis M Nyaga
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | | | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | | | - Davut Pehlivan
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Cassidy Petree
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Carol Saunders
- University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USA
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA
- Center for Pediatric Genomic Medicine Children's Mercy, Kansas City, MO, USA
| | - Ludger Schoels
- German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
- Center for Neurology and Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, 72076, Germany
| | - Vandana Shashi
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Rebecca C Spillmann
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | | | - Paria N Torbati
- Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran
| | - Tulay Tos
- Department of Medical Genetics, University of Health Sciences, Zubeyde Hanim Research and Training Hospital of Women's Health and Diseases, Ankara, Turkey
| | - Maha S Zaki
- Human Genetics and Genome Research Institute, Clinical Genetics Department, National Research Centre, Cairo, Egypt
| | - Dihong Zhou
- University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USA
- Department of Pediatrics, Division of Clinical Genetics, Children's Mercy Hospital, Kansas City, MO, USA
| | - Christiane Zweier
- Department of Human Genetics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jean-François Trempe
- Department of Pharmacology & Therapeutics and Centre de Recherche en Biologie Structurale, McGill University, Montréal, QC, Canada
| | - Thomas M Durcan
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Ziv Gan-Or
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
- Department of Human Genetics, McGill University, Montréal, QC, Canada
| | - Massimo Avoli
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
| | - Cesar Alves
- Division of Neuroradiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Reza Maroofian
- Department of Neuromuscular Diseases, University College London (UCL) Queen Square Institute of Neurology, London, UK
| | - David A Rudko
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada
- McConnell Brain Imaging Centre, the Neuro, Montréal, QC, Canada
- Department of Biomedical Engineering, McGill University, Montréal, QC, Canada
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, the Neuro, McGill University, Montréal, QC, Canada.
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Williams DM, Gungordu L, Jackson-Crawford A, Lowe M. Assessment of endocytic traffic and Ocrl function in the developing zebrafish neuroepithelium. J Cell Sci 2022; 135:276669. [PMID: 35979861 PMCID: PMC9592051 DOI: 10.1242/jcs.260339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/11/2022] [Indexed: 12/05/2022] Open
Abstract
Endocytosis allows cells to internalise a wide range of molecules from their environment and to maintain their plasma membrane composition. It is vital during development and for maintenance of tissue homeostasis. The ability to visualise endocytosis in vivo requires suitable assays to monitor the process. Here, we describe imaging-based assays to visualise endocytosis in the neuroepithelium of living zebrafish embryos. Injection of fluorescent tracers into the brain ventricles followed by live imaging was used to study fluid-phase or receptor-mediated endocytosis, for which we used receptor-associated protein (RAP, encoded by Lrpap1) as a ligand for low-density lipoprotein receptor-related protein (LRP) receptors. Using dual-colour imaging combined with expression of endocytic markers, it is possible to track the progression of endocytosed tracers and to monitor trafficking dynamics. Using these assays, we reveal a role for the Lowe syndrome protein Ocrl in endocytic trafficking within the neuroepithelium. We also found that the RAP-binding receptor Lrp2 (encoded by lrp2a) appears to contribute only partially to neuroepithelial RAP endocytosis. Altogether, our results provide a basis to track endocytosis within the neuroepithelium in vivo and support a role for Ocrl in this process. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Daniel M Williams
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Lale Gungordu
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Anthony Jackson-Crawford
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Martin Lowe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
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3
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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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4
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Kalusa M, Heinrich MD, Sauerland C, Morawski M, Fietz SA. Developmental Differences in Neocortex Neurogenesis and Maturation Between the Altricial Dwarf Rabbit and Precocial Guinea Pig. Front Neuroanat 2021; 15:678385. [PMID: 34135738 PMCID: PMC8200626 DOI: 10.3389/fnana.2021.678385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/06/2021] [Indexed: 11/13/2022] Open
Abstract
Mammals are born on a precocial-altricial continuum. Altricial species produce helpless neonates with closed distant organs incapable of locomotion, whereas precocial species give birth to well-developed young that possess sophisticated sensory and locomotor capabilities. Previous studies suggest that distinct patterns of cortex development differ between precocial and altricial species. This study compares patterns of neocortex neurogenesis and maturation in the precocial guinea pig and altricial dwarf rabbit, both belonging to the taxon of Glires. We show that the principal order of neurodevelopmental events is preserved in the neocortex of both species. Moreover, we show that neurogenesis starts at a later postconceptional day and takes longer in absolute gestational days in the precocial than the altricial neocortex. Intriguingly, our data indicate that the dwarf rabbit neocortex contains a higher abundance of highly proliferative basal progenitors than the guinea pig, which might underlie its higher encephalization quotient, demonstrating that the amount of neuron production is determined by complex regulation of multiple factors. Furthermore, we show that the guinea pig neocortex exhibits a higher maturation status at birth, thus providing evidence for the notions that precocial species might have acquired the morphological machinery required to attain their high functional state at birth and that brain expansion in the precocial newborn is mainly due to prenatally initiating processes of gliogenesis and neuron differentiation instead of increased neurogenesis. Together, this study reveals important insights into the timing and cellular differences that regulate mammalian brain growth and maturation and provides a better understanding of the evolution of mammalian altriciality and presociality.
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Affiliation(s)
- Mirjam Kalusa
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Maren D. Heinrich
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Christine Sauerland
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Markus Morawski
- Medical Faculty, Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Simone A. Fietz
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
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Vasistha NA, Khodosevich K. The impact of (ab)normal maternal environment on cortical development. Prog Neurobiol 2021; 202:102054. [PMID: 33905709 DOI: 10.1016/j.pneurobio.2021.102054] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/01/2021] [Accepted: 04/20/2021] [Indexed: 12/24/2022]
Abstract
The cortex in the mammalian brain is the most complex brain region that integrates sensory information and coordinates motor and cognitive processes. To perform such functions, the cortex contains multiple subtypes of neurons that are generated during embryogenesis. Newly born neurons migrate to their proper location in the cortex, grow axons and dendrites, and form neuronal circuits. These developmental processes in the fetal brain are regulated to a large extent by a great variety of factors derived from the mother - starting from simple nutrients as building blocks and ending with hormones. Thus, when the normal maternal environment is disturbed due to maternal infection, stress, malnutrition, or toxic substances, it might have a profound impact on cortical development and the offspring can develop a variety of neurodevelopmental disorders. Here we first describe the major developmental processes which generate neuronal diversity in the cortex. We then review our knowledge of how most common maternal insults affect cortical development, perturb neuronal circuits, and lead to neurodevelopmental disorders. We further present a concept of selective vulnerability of cortical neuronal subtypes to maternal-derived insults, where the vulnerability of cortical neurons and their progenitors to an insult depends on the time (developmental period), place (location in the developing brain), and type (unique features of a cell type and an insult). Finally, we provide evidence for the existence of selective vulnerability during cortical development and identify the most vulnerable neuronal types, stages of differentiation, and developmental time for major maternal-derived insults.
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Affiliation(s)
- Navneet A Vasistha
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
| | - Konstantin Khodosevich
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
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Signs of Reduced Basal Progenitor Levels and Cortical Neurogenesis in Human Fetuses with Open Spina Bifida at 11-15 Weeks of Gestation. J Neurosci 2020; 40:1766-1777. [PMID: 31953373 DOI: 10.1523/jneurosci.0192-19.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 12/06/2019] [Accepted: 12/30/2019] [Indexed: 12/13/2022] Open
Abstract
Open spina bifida (OSB) is one of the most prevalent congenital malformations of the CNS that often leads to severe disabilities. Previous studies reported the volume and thickness of the neocortex to be altered in children and adolescents diagnosed with OSB. Until now, the onset and the underlying cause of the atypical neocortex organization in OSB patients remain largely unknown. To examine the effects of OSB on fetal neocortex development, we analyzed human fetuses of both sexes diagnosed with OSB between 11 and 15 weeks of gestation by immunofluorescence for established neuronal and neural progenitor marker proteins and compared the results with healthy controls of the same, or very similar, gestational age. Our data indicate that neocortex development in OSB fetuses is altered as early as 11 weeks of gestation. We observed a marked reduction in the radial thickness of the OSB neocortex, which appears to be attributable to a massive decrease in the number of deep- and upper-layer neurons per field, and found a marked reduction in the number of basal progenitors (BPs) per field in the OSB neocortex, consistent with an impairment of cortical neurogenesis underlying the neuronal decrease in OSB fetuses. Moreover, our data suggest that the decrease in BP number in the OSB neocortex may be associated with BPs spending a lesser proportion of their cell cycle in M-phase. Together, our findings expand our understanding of the pathophysiology of OSB and support the need for an early fetal therapy (i.e., in the first trimester of pregnancy).SIGNIFICANCE STATEMENT Open spina bifida (OSB) is one of the most prevalent congenital malformations of the CNS. This study provides novel data on neocortex development of human OSB fetuses. Our data indicate that neocortex development in OSB fetuses is altered as early as 11 weeks of gestation. We observed a marked reduction in the radial thickness of the OSB neocortex, which appears to be attributable a decrease in the number of deep- and upper-layer neurons per field, and found a marked reduction in the number of basal progenitors per field, indicating that impaired neurogenesis underlies the neuronal decrease in OSB fetuses. Our findings support the need for an early fetal therapy and expand our understanding of the pathophysiology of OSB.
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7
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Singh A, Castillo HA, Brown J, Kaslin J, Dwyer KM, Gibert Y. High glucose levels affect retinal patterning during zebrafish embryogenesis. Sci Rep 2019; 9:4121. [PMID: 30858575 PMCID: PMC6411978 DOI: 10.1038/s41598-019-41009-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 02/12/2019] [Indexed: 02/08/2023] Open
Abstract
Maternal hyperglycaemia has a profound impact on the developing foetus and increases the risk of developing abnormalities like obesity, impaired glucose tolerance and insulin secretory defects in the post-natal life. Increased levels of glucose in the blood stream due to diabetes causes visual disorders like retinopathy. However, the impact of maternal hyperglycaemia due to pre-existing or gestational diabetes on the developing foetal retina is unknown. The aim of this work was to study the effect of hyperglycaemia on the developing retina using zebrafish as a vertebrate model. Wild-type and transgenic zebrafish embryos were exposed to 0, 4 and 5% D-Glucose in a pulsatile manner to mimic the fluctuations in glycaemia experienced by the developing foetus in pregnant women with diabetes. The zebrafish embryos displayed numerous ocular defects associated with altered retinal cell layer thickness, increased presence of macrophages, and decreased number of Müeller glial and retinal ganglion cells following high-glucose exposure. We have developed a model of gestational hyperglycaemia using the zebrafish embryo to study the effect of hyperglycaemia on the developing embryonic retina. The data suggests that glucose exposure is detrimental to the development of embryonic retina and the legacy of this exposure may extend into adulthood. These data suggest merit in retinal assessment in infants born to mothers with pre-existing and gestational diabetes both in early and adult life.
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Affiliation(s)
- Amitoj Singh
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Road, Waurn Ponds, Geelong, VIC, 3216, Australia
| | - Hozana Andrade Castillo
- Monash University, Australian Regenerative Medicine Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
- Brazilian Biosciences National Laboratory, Brazilian Centre for Research in Energy and Materials, Campinas, Brazil
| | - Julie Brown
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Road, Waurn Ponds, Geelong, VIC, 3216, Australia
| | - Jan Kaslin
- Monash University, Australian Regenerative Medicine Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - Karen M Dwyer
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Road, Waurn Ponds, Geelong, VIC, 3216, Australia
| | - Yann Gibert
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Road, Waurn Ponds, Geelong, VIC, 3216, Australia.
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8
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Takahashi H, Yoshihara S, Tsuboi A. The Functional Role of Olfactory Bulb Granule Cell Subtypes Derived From Embryonic and Postnatal Neurogenesis. Front Mol Neurosci 2018; 11:229. [PMID: 30034321 PMCID: PMC6043811 DOI: 10.3389/fnmol.2018.00229] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 06/12/2018] [Indexed: 02/01/2023] Open
Abstract
It has been shown in a variety of mammalian species that sensory experience can regulate the development of various structures, including the retina, cortex, hippocampus, and olfactory bulb (OB). In the mammalian OB, the development of dendrites in excitatory projection neurons, such as mitral and tufted cells, is well known to be dependent on odor experience. Odor experience is also involved in the development of another OB population, a subset of inhibitory interneurons that are generated in the ventricular-subventricular zone throughout life and differentiate into granule cells (GCs) and periglomerular cells. However, the roles that each type of interneuron plays in the control of olfactory behaviors are incompletely understood. We recently found that among the various types of OB interneurons, a subtype of GCs expressing the oncofetal trophoblast glycoprotein 5T4 gene is required for odor detection and discrimination behaviors. Our results suggest that embryonic-born OB interneurons, including 5T4-positive GCs, play a crucial role in fundamental olfactory responses such as simple odor detection and discrimination behaviors. By contrast, postnatal- and adult-born OB interneurons are important in the learning of more complicated olfactory behaviors. Here, we highlight the subtypes of OB GCs, and discuss their roles in olfactory processing and behavior, with a particular focus on the relative contributions of embryonically and postnatally generated subsets of GCs in rodents.
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Affiliation(s)
- Hiroo Takahashi
- Laboratory for the Molecular Biology of Neural Systems, Advanced Medical Research Center, Nara Medical University, Kashihara, Japan
| | - Seiichi Yoshihara
- Laboratory for the Molecular Biology of Neural Systems, Advanced Medical Research Center, Nara Medical University, Kashihara, Japan
| | - Akio Tsuboi
- Laboratory for the Molecular Biology of Neural Systems, Advanced Medical Research Center, Nara Medical University, Kashihara, Japan.,Laboratory for the Molecular and Cellular Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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9
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Römer S, Bender H, Knabe W, Zimmermann E, Rübsamen R, Seeger J, Fietz SA. Neural Progenitors in the Developing Neocortex of the Northern Tree Shrew ( Tupaia belangeri) Show a Closer Relationship to Gyrencephalic Primates Than to Lissencephalic Rodents. Front Neuroanat 2018; 12:29. [PMID: 29725291 PMCID: PMC5917011 DOI: 10.3389/fnana.2018.00029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/03/2018] [Indexed: 01/03/2023] Open
Abstract
The neocortex is the most complex part of the mammalian brain and as such it has undergone tremendous expansion during evolution, especially in primates. The majority of neocortical neurons originate from distinct neural stem and progenitor cells (NPCs) located in the ventricular and subventricular zone (SVZ). Previous studies revealed that the SVZ thickness as well as the abundance and distribution of NPCs, especially that of basal radial glia (bRG), differ markedly between the lissencephalic rodent and gyrencephalic primate neocortex. The northern tree shrew (Tupaia belangeri) is a rat-sized mammal with a high brain to body mass ratio, which stands phylogenetically mid-way between rodents and primates. Our study provides – for the first time – detailed data on the presence, abundance and distribution of bRG and other distinct NPCs in the developing neocortex of the northern tree shrew (Tupaia belangeri). We show that the developing tree shrew neocortex is characterized by an expanded SVZ, a high abundance of Pax6+ NPCs in the SVZ, and a relatively high percentage of bRG at peak of upper-layer neurogenesis. We further demonstrate that key features of tree shrew neocortex development, e.g., the presence, abundance and distribution of distinct NPCs, are closer related to those of gyrencephalic primates than to those of ferret and lissencephalic rodents. Together, our study provides novel insight into the evolution of bRG and other distinct NPCs in the neocortex development of Euarchontoglires and introduces the tree shrew as a potential novel model organism in the area of human brain development and developmental disorders.
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Affiliation(s)
- Sebastian Römer
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Hannah Bender
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Wolfgang Knabe
- Prosektur Anatomie, Medizinische Fakultät, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Elke Zimmermann
- Institute of Zoology, University of Veterinary Medicine Hanover, Hanover, Germany
| | - Rudolf Rübsamen
- Institute of Biology, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany
| | - Johannes Seeger
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Simone A Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
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10
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Götz M. Glial Cells Generate Neurons—Master Control within CNS Regions: Developmental Perspectives on Neural Stem Cells. Neuroscientist 2016; 9:379-97. [PMID: 14580122 DOI: 10.1177/1073858403257138] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A common problem in neural stem cell research is the poor generation of neuronal or oligodendroglial descendants. The author takes a developmental perspective to propose solutions to this problem. After a general overview of the recent progress in developmental neurobiology, she highlights the necessity of the sequential and hierarchical specification of CNS precursors toward the generation of specific cell types, for example, neurons. In the developing as well as the adult CNS, multipotent stem cells do not directly generate neurons but give rise to precursors that are specified and restricted toward the generation of neurons. Some molecular determinants of this fate restriction have been identified during recent years and reveal that progression via this fate-restricted state is a necessary step of neurogenesis. These discoveries also demonstrate that neuronal fate specification is inseparably linked at the molecular level to regionalization of the developing CNS. These fate determinants and their specific action in distinct region-specific con-texts are essential to direct the progeny of stem cells more efficiently toward the generation of the desired cell types. Recent data are discussed that demonstrate the common identity of precursors and stem cells in the developing and adult nervous system as radial glia, astroglia, or non-myelinating glia. A novel line-age model is proposed that incorporates these new views and explains why the default pathway of stem cells is astroglia. These new insights into the cellular and molecular mechanisms of neurogenesis help to design novel approaches for reconstitutive therapy of neurodegenerative diseases.
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Affiliation(s)
- Magdalena Götz
- Max-Planck Institute of Neurobiology, Planegg-Martinsried/Munich, Germany.
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11
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Gordon NK, Gordon R. The organelle of differentiation in embryos: the cell state splitter. Theor Biol Med Model 2016; 13:11. [PMID: 26965444 PMCID: PMC4785624 DOI: 10.1186/s12976-016-0037-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/27/2016] [Indexed: 12/16/2022] Open
Abstract
The cell state splitter is a membraneless organelle at the apical end of each epithelial cell in a developing embryo. It consists of a microfilament ring and an intermediate filament ring subtending a microtubule mat. The microtubules and microfilament ring are in mechanical opposition as in a tensegrity structure. The cell state splitter is bistable, perturbations causing it to contract or expand radially. The intermediate filament ring provides metastability against small perturbations. Once this snap-through organelle is triggered, it initiates signal transduction to the nucleus, which changes gene expression in one of two readied manners, causing its cell to undergo a step of determination and subsequent differentiation. The cell state splitter also triggers the cell state splitters of adjacent cells to respond, resulting in a differentiation wave. Embryogenesis may be represented then as a bifurcating differentiation tree, each edge representing one cell type. In combination with the differentiation waves they propagate, cell state splitters explain the spatiotemporal course of differentiation in the developing embryo. This review is excerpted from and elaborates on "Embryogenesis Explained" (World Scientific Publishing, Singapore, 2016).
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Affiliation(s)
| | - Richard Gordon
- />Retired, University of Manitoba, Winnipeg, Canada
- />Embryogenesis Center, Gulf Specimen Aquarium & Marine Laboratory, 222 Clark Drive, Panacea, FL 32346 USA
- />C.S. Mott Center for Human Growth & Development, Department of Obstetrics & Gynecology, Wayne State University, 275 E. Hancock, Detroit, MI 48201 USA
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12
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Progenitor genealogy in the developing cerebral cortex. Cell Tissue Res 2014; 359:17-32. [PMID: 25141969 DOI: 10.1007/s00441-014-1979-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
The mammalian cerebral cortex is characterized by a complex histological organization that reflects the spatio-temporal stratifications of related stem and neural progenitor cells, which are responsible for the generation of distinct glial and neuronal subtypes during development. Some work has been done to shed light on the existing filiations between these progenitors as well as their respective contribution to cortical neurogenesis. The aim of the present review is to summarize the current views of progenitor hierarchy and relationship in the developing cortex and to further discuss future research directions that would help us to understand the molecular and cellular regulating mechanisms involved in cerebral corticogenesis.
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13
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Paridaen JTML, Wilsch-Bräuninger M, Huttner WB. Asymmetric inheritance of centrosome-associated primary cilium membrane directs ciliogenesis after cell division. Cell 2013; 155:333-44. [PMID: 24120134 DOI: 10.1016/j.cell.2013.08.060] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 06/28/2013] [Accepted: 08/27/2013] [Indexed: 12/14/2022]
Abstract
Primary cilia are key sensory organelles that are thought to be disassembled prior to mitosis. Inheritance of the mother centriole, which nucleates the primary cilium, in relation to asymmetric daughter cell behavior has previously been studied. However, the fate of the ciliary membrane upon cell division is unknown. Here, we followed the ciliary membrane in dividing embryonic neocortical stem cells and cultured cells. Ciliary membrane attached to the mother centriole was endocytosed at mitosis onset, persisted through mitosis at one spindle pole, and was asymmetrically inherited by one daughter cell, which retained stem cell character. This daughter re-established a primary cilium harboring an activated signal transducer earlier than the noninheriting daughter. Centrosomal association of ciliary membrane in dividing neural stem cells decreased at late neurogenesis when these cells differentiate. Our data imply that centrosome-associated ciliary membrane acts as a determinant for the temporal-spatial control of ciliogenesis.
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Affiliation(s)
- Judith T M L Paridaen
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraβe 108, 01307 Dresden, Germany
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14
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Mack AF, Wolburg H. A novel look at astrocytes: aquaporins, ionic homeostasis, and the role of the microenvironment for regeneration in the CNS. Neuroscientist 2012; 19:195-207. [PMID: 22645111 DOI: 10.1177/1073858412447981] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aquaporin-4 (AQP4) water channels are located at the basolateral membrane domain of many epithelial cells involved in ion transport and secretion. These epithelial cells separate fluid compartments by forming apical tight junctions. In the brain, AQP4 is located on astrocytes in a polarized distribution: At the border to blood vessels or the pial surface, its density is very high. During ontogeny and phylogeny, astroglial cells go through a stage of expressing tight junctions, separating fluid compartments differently than in adult mammals. In adult mammals, this barrier is formed by arachnoid, choroid plexus, and endothelial cells. The ontogenetic and phylogenetic barrier transition from glial to endothelial cells correlates with the regenerative capacity of neuronal structures: Glial cells forming tight junctions, and expressing no or unpolarized AQP4 are found in the fish optic nerve and the olfactory nerve in mammals both known for their regenerative ability. It is hypothesized that highly polarized AQP4 expression and the lack of tight junctions on astrocytes increase ionic homeostasis, thus improving neuronal performance possibly at the expense of restraining neurogenesis and regeneration.
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Affiliation(s)
- Andreas F Mack
- Institute of Anatomy, University of Tübingen, Tübingen, Germany.
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15
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Guerrero-Cazares H, Attenello FJ, Noiman L, Quiñones-Hinojosa A. Stem cells in gliomas. HANDBOOK OF CLINICAL NEUROLOGY 2012; 104:63-73. [PMID: 22230436 DOI: 10.1016/b978-0-444-52138-5.00006-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Hugo Guerrero-Cazares
- Department of Neurosurgery, John Hopkins University School of Medicine, Baltimore, MD, USA
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16
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Abstract
Cerebral cortical progenitor cells can be classified into several different types, and each progenitor type integrates cell-intrinsic and cell-extrinsic cues to regulate neurogenesis. On one hand, cell-intrinsic mechanisms that depend upon appropriate apical-basal polarity are established by adherens junctions and apical complex proteins and are particularly important in progenitors with apical processes contacting the lateral ventricle. The apical protein complexes themselves are concentrated at the ventricular surface, and apical complex proteins regulate mitotic spindle orientation and cell fate. On the other hand, remarkably little is known about how cell-extrinsic cues signal to progenitors and couple with cell-intrinsic mechanisms to instruct neurogenesis. Recent research shows that the cerebrospinal fluid, which contacts apical progenitors at the ventricular surface and bathes the apical complex of these cells, provides growth- and survival-promoting cues for neural progenitor cells in developing and adult brain. This review addresses how the apical-basal polarity of progenitor cells regulates cell fate and allows progenitors to sample diffusible signals distributed by the cerebrospinal fluid. We also review several classes of signaling factors that the cerebrospinal fluid distributes to the developing brain to instruct neurogenesis.
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Affiliation(s)
- Maria K Lehtinen
- Division of Genetics, Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA.
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17
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Peyre E, Jaouen F, Saadaoui M, Haren L, Merdes A, Durbec P, Morin X. A lateral belt of cortical LGN and NuMA guides mitotic spindle movements and planar division in neuroepithelial cells. ACTA ACUST UNITED AC 2011; 193:141-54. [PMID: 21444683 PMCID: PMC3082188 DOI: 10.1083/jcb.201101039] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knockdown or mislocalization of LGN complex components disrupts the stereotypic biphasic spindle movements regulating planar cell division and neuroepithelial structure in chick embryos. To maintain tissue architecture, epithelial cells divide in a planar fashion, perpendicular to their main polarity axis. As the centrosome resumes an apical localization in interphase, planar spindle orientation is reset at each cell cycle. We used three-dimensional live imaging of GFP-labeled centrosomes to investigate the dynamics of spindle orientation in chick neuroepithelial cells. The mitotic spindle displays stereotypic movements during metaphase, with an active phase of planar orientation and a subsequent phase of planar maintenance before anaphase. We describe the localization of the NuMA and LGN proteins in a belt at the lateral cell cortex during spindle orientation. Finally, we show that the complex formed of LGN, NuMA, and of cortically located Gαi subunits is necessary for spindle movements and regulates the dynamics of spindle orientation. The restricted localization of LGN and NuMA in the lateral belt is instructive for the planar alignment of the mitotic spindle, and required for its planar maintenance.
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Affiliation(s)
- Elise Peyre
- Université de la Méditerranée/Aix-Marseille II, Developmental Biology Institute (IBDML), Centre National de la Recherche Scientifique UMR6216, Case 907, Campus de Luminy, 13288 Marseille, France
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18
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Corbeil D, Marzesco AM, Wilsch-Bräuninger M, Huttner WB. The intriguing links between prominin-1 (CD133), cholesterol-based membrane microdomains, remodeling of apical plasma membrane protrusions, extracellular membrane particles, and (neuro)epithelial cell differentiation. FEBS Lett 2010; 584:1659-64. [PMID: 20122930 DOI: 10.1016/j.febslet.2010.01.050] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 01/25/2010] [Indexed: 12/13/2022]
Abstract
Prominin-1 (CD133) is a cholesterol-interacting pentaspan membrane protein concentrated in plasma membrane protrusions. In epithelial cells, notably neuroepithelial stem cells, prominin-1 is found in microvilli, the primary cilium and the midbody. These three types of apical membrane protrusions are subject to remodeling during (neuro)epithelial cell differentiation. The protrusion-specific localization of prominin involves its association with a distinct cholesterol-based membrane microdomain. Moreover, the three prominin-1-containing plasma membrane protrusions are the origin of at least two major subpopulations of prominin-1-containing extracellular membrane particles. Intriguingly, the release of these particles has been implicated in (neuro)epithelial cell differentiation.
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Affiliation(s)
- Denis Corbeil
- Tissue Engineering Laboratories, BIOTEC, Technische Universität Dresden, Dresden, Germany
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19
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Corbeil D, Marzesco AM, Fargeas CA, Huttner WB. Prominin-1: a distinct cholesterol-binding membrane protein and the organisation of the apical plasma membrane of epithelial cells. Subcell Biochem 2010; 51:399-423. [PMID: 20213552 DOI: 10.1007/978-90-481-8622-8_14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The apical plasma membrane of polarized epithelial cells is composed of distinct subdomains, that is, planar regions and protrusions (microvilli, primary cilium), each of which are constructed from specific membrane microdomains. Assemblies containing the pentaspan glycoprotein prominin-1 and certain membrane lipids, notably cholesterol, are characteristic features of these microdomains in apical membrane protrusions. Here we highlight the recent findings concerning the molecular architecture of the apical plasma membrane of epithelial cells and its dynamics. The latter is illustrated by the budding and fission of prominin-1-containing membrane vesicles from apical plasma membrane protrusions, which is controlled, at least in part, by the level of membrane cholesterol and the cholesterol-dependent organization of membrane microdomains.
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Affiliation(s)
- Denis Corbeil
- Tissue Engineering Laboratories, BIOTEC, Technische Universität Dresden, Tatzberg 47-49, 01307, Dresden, Germany.
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20
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Abstract
Glial cells were long considered end products of neural differentiation, specialized supportive cells with an origin very different from that of neurons. New studies have shown that some glial cells--radial glia (RG) in development and specific subpopulations of astrocytes in adult mammals--function as primary progenitors or neural stem cells (NSCs). This is a fundamental departure from classical views separating neuronal and glial lineages early in development. Direct visualization of the behavior of NSCs and lineage-tracing studies reveal how neuronal lineages emerge. In development and in the adult brain, many neurons and glial cells are not the direct progeny of NSCs, but instead originate from transit amplifying, or intermediate, progenitor cells (IPCs). Within NSCs and IPCs, genetic programs unfold for generating the extraordinary diversity of cell types in the central nervous system. The timing in development and location of NSCs, a property tightly linked to their neuroepithelial origin, appear to be the key determinants of the types of neurons generated. Identification of NSCs and IPCs is critical to understand brain development and adult neurogenesis and to develop new strategies for brain repair.
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Affiliation(s)
- Arnold Kriegstein
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Department of Neurology, University of California, San Francisco, California 94143-0525, USA.
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21
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Harrington MJ, Hong E, Brewster R. Comparative analysis of neurulation: First impressions do not count. Mol Reprod Dev 2009; 76:954-65. [DOI: 10.1002/mrd.21085] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Attardo A, Calegari F, Haubensak W, Wilsch-Bräuninger M, Huttner WB. Live imaging at the onset of cortical neurogenesis reveals differential appearance of the neuronal phenotype in apical versus basal progenitor progeny. PLoS One 2008; 3:e2388. [PMID: 18545663 PMCID: PMC2398773 DOI: 10.1371/journal.pone.0002388] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Accepted: 04/29/2008] [Indexed: 12/14/2022] Open
Abstract
The neurons of the mammalian brain are generated by progenitors dividing either at the apical surface of the ventricular zone (neuroepithelial and radial glial cells, collectively referred to as apical progenitors) or at its basal side (basal progenitors, also called intermediate progenitors). For apical progenitors, the orientation of the cleavage plane relative to their apical-basal axis is thought to be of critical importance for the fate of the daughter cells. For basal progenitors, the relationship between cell polarity, cleavage plane orientation and the fate of daughter cells is unknown. Here, we have investigated these issues at the very onset of cortical neurogenesis. To directly observe the generation of neurons from apical and basal progenitors, we established a novel transgenic mouse line in which membrane GFP is expressed from the beta-III-tubulin promoter, an early pan-neuronal marker, and crossed this line with a previously described knock-in line in which nuclear GFP is expressed from the Tis21 promoter, a pan-neurogenic progenitor marker. Mitotic Tis21-positive basal progenitors nearly always divided symmetrically, generating two neurons, but, in contrast to symmetrically dividing apical progenitors, lacked apical-basal polarity and showed a nearly randomized cleavage plane orientation. Moreover, the appearance of beta-III-tubulin–driven GFP fluorescence in basal progenitor-derived neurons, in contrast to that in apical progenitor-derived neurons, was so rapid that it suggested the initiation of the neuronal phenotype already in the progenitor. Our observations imply that (i) the loss of apical-basal polarity restricts neuronal progenitors to the symmetric mode of cell division, and that (ii) basal progenitors initiate the expression of neuronal phenotype already before mitosis, in contrast to apical progenitors.
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Affiliation(s)
- Alessio Attardo
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Federico Calegari
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Wulf Haubensak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail:
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23
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Noctor SC, Martínez-Cerdeño V, Kriegstein AR. Distinct behaviors of neural stem and progenitor cells underlie cortical neurogenesis. J Comp Neurol 2008; 508:28-44. [PMID: 18288691 PMCID: PMC2635107 DOI: 10.1002/cne.21669] [Citation(s) in RCA: 287] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neocortical precursor cells undergo symmetric and asymmetric divisions while producing large numbers of diverse cortical cell types. In Drosophila, cleavage plane orientation dictates the inheritance of fate-determinants and the symmetry of newborn daughter cells during neuroblast cell divisions. One model for predicting daughter cell fate in the mammalian neocortex is also based on cleavage plane orientation. Precursor cell divisions with a cleavage plane orientation that is perpendicular with respect to the ventricular surface (vertical) are predicted to be symmetric, while divisions with a cleavage plane orientation that is parallel to the surface (horizontal) are predicted to be asymmetric neurogenic divisions. However, analysis of cleavage plane orientation at the ventricle suggests that the number of predicted neurogenic divisions might be insufficient to produce large amounts of cortical neurons. To understand factors that correlate with the symmetry of cell divisions, we examined rat neocortical precursor cells in situ through real-time imaging, marker analysis, and electrophysiological recordings. We find that cleavage plane orientation is more closely associated with precursor cell type than with daughter cell fate, as commonly thought. Radial glia cells in the VZ primarily divide with a vertical orientation throughout cortical development and undergo symmetric or asymmetric self-renewing divisions depending on the stage of development. In contrast, most intermediate progenitor cells divide in the subventricular zone with a horizontal orientation and produce symmetric daughter cells. We propose a model for predicting daughter cell fate that considers precursor cell type, stage of development, and the planar segregation of fate determinants.
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Affiliation(s)
- Stephen C Noctor
- Department of Neurology, University of California, San Francisco, San Francisco, California 94143, USA.
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24
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Lee C, Scherr HM, Wallingford JB. Shroom family proteins regulate gamma-tubulin distribution and microtubule architecture during epithelial cell shape change. Development 2007; 134:1431-41. [PMID: 17329357 DOI: 10.1242/dev.02828] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell shape changes require the coordination of actin and microtubule cytoskeletons. The molecular mechanisms by which such coordination is achieved remain obscure, particularly in the context of epithelial cells within developing vertebrate embryos. We have identified a novel role for the actin-binding protein Shroom3 as a regulator of the microtubule cytoskeleton during epithelial morphogenesis. We show that Shroom3 is sufficient and also necessary to induce a redistribution of the microtubule regulator gamma-tubulin. Moreover, this change in gamma-tubulin distribution underlies the assembly of aligned arrays of microtubules that drive apicobasal cell elongation. Finally, experiments with the related protein, Shroom1, demonstrate that gamma-tubulin regulation is a conserved feature of this protein family. Together, the data demonstrate that Shroom family proteins govern epithelial cell behaviors by coordinating the assembly of both microtubule and actin cytoskeletons.
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Affiliation(s)
- Chanjae Lee
- Department of Molecular Cell and Developmental Biology, and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
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25
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Dubreuil V, Marzesco AM, Corbeil D, Huttner WB, Wilsch-Bräuninger M. Midbody and primary cilium of neural progenitors release extracellular membrane particles enriched in the stem cell marker prominin-1. ACTA ACUST UNITED AC 2007; 176:483-95. [PMID: 17283184 PMCID: PMC2063983 DOI: 10.1083/jcb.200608137] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Expansion of the neocortex requires symmetric divisions of neuroepithelial cells, the primary progenitor cells of the developing mammalian central nervous system. Symmetrically dividing neuroepithelial cells are known to form a midbody at their apical (rather than lateral) surface. We show that apical midbodies of neuroepithelial cells concentrate prominin-1 (CD133), a somatic stem cell marker and defining constituent of a specific plasma membrane microdomain. Moreover, these apical midbodies are released, as a whole or in part, into the extracellular space, yielding the prominin-1–enriched membrane particles found in the neural tube fluid. The primary cilium of neuroepithelial cells also concentrates prominin-1 and appears to be a second source of the prominin-1–bearing extracellular membrane particles. Our data reveal novel origins of extracellular membrane traffic that enable neural stem and progenitor cells to avoid the asymmetric inheritance of the midbody observed for other cells and, by releasing a stem cell membrane microdomain, to potentially influence the balance of their proliferation versus differentiation.
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Affiliation(s)
- Véronique Dubreuil
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany
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26
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McDermott KW, Barry DS, McMahon SS. Role of radial glia in cytogenesis, patterning and boundary formation in the developing spinal cord. J Anat 2006; 207:241-50. [PMID: 16185248 PMCID: PMC1571535 DOI: 10.1111/j.1469-7580.2005.00462.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Radial glial fibres provide a transient scaffold and impose constraints in the developing central nervous system (CNS) that facilitate cell migration and axon growth. Recent reports have raised doubts about the distinction between radial glia and precursor cells by demonstrating that radial glia are themselves neuronal progenitor cells in the developing cortex, indicating a dual role for radial glia in both neurogenesis and migration guidance. Radial glia shift toward exclusive generation of astrocytes after neurogenesis has ceased. Radial progenitor cell differentiation and lineage relationships in CNS development are complex processes depending on genetic programming, cell-cell interaction and microenvironmental factors. In the spinal cord, radial cells that arise directly from the neuroepithelium have been identified. At least in the spinal cord, these radial cells appear to be the precursors to radial glia. It remains unknown whether radial glial cells or their precursors, the radial cells, or both can give rise to neurons in the spinal cord. Radial glial cells are also important in regulating the axon out-growth and pathfinding processes that occur during white matter patterning of the developing spinal cord.
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Affiliation(s)
- Kieran W McDermott
- Department of Anatomy, Windle Building and Biosciences Institute, University College Cork, Cork, Ireland.
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27
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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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28
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Marzesco AM, Janich P, Wilsch-Bräuninger M, Dubreuil V, Langenfeld K, Corbeil D, Huttner WB. Release of extracellular membrane particles carrying the stem cell marker prominin-1 (CD133) from neural progenitors and other epithelial cells. J Cell Sci 2005; 118:2849-58. [PMID: 15976444 DOI: 10.1242/jcs.02439] [Citation(s) in RCA: 354] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Apical plasma membrane constituents of mammalian neural stem/progenitor cells have recently been implicated in maintaining their stem/progenitor cell state. Here, we report that in the developing embryonic mouse brain, the fluid in the lumen of the neural tube contains membrane particles carrying the stem cell marker prominin-1 (CD133), a pentaspan membrane protein found on membrane protrusions of the apical surface of neuroepithelial cells. Two size classes of prominin-1-containing membrane particles were observed in the ventricular fluid: approximately 600-nm particles, referred to as P2 particles, and 50-80-nm vesicles, referred to as P4 particles. The P2 and P4 particles appeared in the ventricular fluid at the very onset and during the early phase of neurogenesis, respectively. Concomitant with their appearance, the nature of the prominin-1-containing apical plasma membrane protrusions of neuroepithelial cells changed, in that microvilli were lost and large pleiomorphic protuberances appeared. P4 particles were found in various body fluids of adult humans, including saliva, seminal fluid and urine, and were released by the epithelial model cell line Caco-2 upon differentiation. Importantly, P4 particles were distinct from exosomes. Our results demonstrate the widespread occurrence of a novel class of extracellular membrane particles containing proteins characteristic of stem cells, and raise the possibility that the release of the corresponding membrane subdomains from the apical surface of neural progenitors and other epithelial cells may have a role in tissue development and maintenance. Moreover, the presence of prominin-1-containing membrane particles in human body fluids may provide the basis for a protein-based diagnosis of certain diseases.
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Affiliation(s)
- Anne-Marie Marzesco
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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Abstract
The majority of cells that build the nervous system of animals are generated early in embryonic development in a process called neurogenesis. Although the vertebrate nervous system is much more complex than that of insects, the underlying principles of neurogenesis are intriguingly similar. In both cases, neuronal cells are derived from polarized progenitor cells that divide asymmetrically. One daughter cell will continue to divide and the other daughter cell leaves the cell cycle and starts to differentiate as a neuron or a glia cell. In Drosophila, this process has been analyzed in great detail and several of the key players that control asymmetric cell division in the developing nervous system have been identified over the past years. Asymmetric cell division in vertebrate neurogenesis has been studied mostly at a descriptive level and so far little is known about the molecular mechanisms that control this process. In this review we will focus on recent findings dealing with asymmetric cell division during neurogenesis in Drosophila and vertebrates and will discuss common principles and apparent differences between both systems.
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Affiliation(s)
- Andreas Wodarz
- Institut für Genetik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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Abstract
Early in development of the central nervous system, radial glial cells arise from the neuroepithelial cells lining the ventricles around the time that neurons begin to appear. The transition of neuroepithelial cells to radial glia is accompanied by a series of structural and functional changes, including the appearance of "glial" features, as well as the appearance of new signaling molecules and junctional proteins. However, not all radial glia are alike. Radial glial lineages appear to be heterogeneous both within and across different brain regions. Subtypes of neurogenic radial glia within the cortex, for example, may have restricted potential in terms of the cell types they are able to generate. Radial glia located in different brain regions also differ in their expression of growth factors, a diverse number of transcription factors, and the cell types they generate, suggesting that they are involved in regionalization of the developing nervous system in several aspects. These findings highlight the important but complex role of radial glia as participants in key steps of brain development.
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Affiliation(s)
- Arnold R Kriegstein
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Magdalena Götz
- Max-Planck Institute of Neurobiology, Planegg-Martinsried, Germany
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31
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Stuckmann I, Evans S, Lassar AB. Erythropoietin and retinoic acid, secreted from the epicardium, are required for cardiac myocyte proliferation. Dev Biol 2003; 255:334-49. [PMID: 12648494 DOI: 10.1016/s0012-1606(02)00078-7] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have established a heart slice primary culture, which allows us to mechanically separate distinct cardiac cell populations and assay their relative mitogenic and trophic effects on cardiac myocyte proliferation and survival. Using this system, we have found that a signal(s) from the epicardium, but not the trabeculae and endocardium, is required in embryonic day 10 (E10) chick heart slices for continued cardiac myocyte proliferation and survival. An examination of potential epicardial growth or trophic factors has revealed that blockade of either retinoic acid (RA) or erythopoietin (epo) signaling from the epicardium inhibits cardiac myocyte proliferation and survival. The blockade of cardiac myocyte proliferation following administration of an RA antagonist can be rescued by exogenous epo. Conversely, the blockade of cardiac myocyte proliferation following administration of an anti-epo receptor antisera can be rescued by exogenous RA. Thus, our findings suggest that RA and epo signals work in parallel to support myocardial cell proliferation. In addition, we have found that these factors do not act directly on myocardial cells. Rather, they induce another soluble factor(s) in the epicardium that directly regulates proliferation of cardiac myocytes. We therefore postulate that the epicardium controls normal heart growth in ventricular segments of the embryonic chick heart by secreting a cardiac myocyte mitogen whose expression (or activity) is regulated by both RA and erythropoietin signaling.
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Affiliation(s)
- Ingo Stuckmann
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
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32
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Malatesta P, Hack MA, Hartfuss E, Kettenmann H, Klinkert W, Kirchhoff F, Götz M. Neuronal or glial progeny: regional differences in radial glia fate. Neuron 2003; 37:751-64. [PMID: 12628166 DOI: 10.1016/s0896-6273(03)00116-8] [Citation(s) in RCA: 546] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The precursor function of the ubiquitous glial cell type in the developing central nervous system (CNS), the radial glia, is largely unknown. Using Cre/loxP in vivo fate mapping studies, we found that radial glia generate virtually all cortical projection neurons but not the interneurons originating in the ventral telencephalon. In contrast to the cerebral cortex, few neurons in the basal ganglia originate from radial glia, and in vitro lineage analysis revealed intrinsic differences in the potential of radial glia from the dorsal and ventral telencephalon. This shows that the progeny of radial glia not only differs profoundly between brain regions but also includes the majority of neurons in some parts of the CNS.
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Affiliation(s)
- Paolo Malatesta
- Max-Planck Institute of Neurobiology, Am Klopferspitz 18A, D-82152 Planegg-Martinsried, Germany
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33
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Rustom A, Bajohrs M, Kaether C, Keller P, Toomre D, Corbeil D, Gerdes HH. Selective delivery of secretory cargo in Golgi-derived carriers of nonepithelial cells. Traffic 2002; 3:279-88. [PMID: 11929609 DOI: 10.1034/j.1600-0854.2002.030405.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In epithelial cells, soluble cargo proteins destined for basolateral or apical secretion are packaged into distinct trans-Golgi network-derived transport carriers. Similar carriers, termed basolateral- and apical-like, have been observed in nonepithelial cells using ectopically expressed membrane marker proteins. Whether these cells are capable of selectively packaging secretory proteins into distinct carriers is still an open question. Here, we have addressed this issue by analyzing the packaging and transport of secretory human chromogranin B fusion proteins using a green fluorescent protein-based high-resolution, dual-color imaging technique. We were able to show that these secretory markers were selectively packaged at the Golgi into tubular/vesicular-like transport carriers containing basolateral membrane markers, resulting in extensive cotransport. In contrast, deletion mutants of the human chromogranin B fusion proteins lacking an N-terminal loop structure were efficiently transported in both basolateral- and apical-like carriers, the latter displaying a spherical morphology. Similarly, in polarized epithelial cells, the human chromogranin B fusion protein was secreted basolaterally and the loop-deleted analogue into both the basolateral and apical medium. These findings suggest that nonepithelial cells, like their epithelial counterparts, possess a sorting machinery capable of selective packaging of secretory cargo into distinct types of carriers.
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Affiliation(s)
- Amin Rustom
- Department of Neurobiology, Interdisciplinary Center of Neuroscience, University of Heidelberg, INF 364, Germany
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Pujic Z, Malicki J. Mutation of the zebrafish glass onion locus causes early cell-nonautonomous loss of neuroepithelial integrity followed by severe neuronal patterning defects in the retina. Dev Biol 2001; 234:454-69. [PMID: 11397013 DOI: 10.1006/dbio.2001.0251] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mutation of the glass onion locus causes drastic neuronal patterning defects in the zebrafish retina and brain. The precise stratified appearance of the wild-type retina is absent in the mutants. The glass onion phenotype is first visible shortly after the formation of optic primordia and is characterized by the rounding of cells and disruption of the ventricular surface in the eye and brain neuroepithelia. With exception of the dorsal- and ventral-most regions of the brain, neuroepithelial cells lose their integrity and begin to distribute ectopically. At later stages, the laminar patterning of retinal neurons is severely disrupted. Despite the lack of lamination, individual retinal cell classes differentiate in the glass onion retina. Mosaic analysis reveals that the glass onion mutation acts cell nonautonomously within the retina and brain, as neuroepithelial cell morphology and polarity in these tissues are normal when mutant cells develop in wild-type hosts. We conclude that the glass onion mutation affects cell-cell signaling event(s) involved in the maintenance of the neuroepithelial cell layer shortly after its formation. The disruption of neuroepithelial integrity may be the cause of the neuronal patterning defects following neurogenesis. In addition, the expression of the glass onion phenotype in a subset of neuroepithelial cells as well as its onset following the initial formation of the neuroepithelial sheets indicate the presence of genetically distinct temporal and spatial subdivisions in the development of this histologically uniform tissue.
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Affiliation(s)
- Z Pujic
- Department of Ophthalmology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts 02114, USA
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35
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Abstract
To identify molecules involved in neurogenesis, we have raised monoclonal antibodies against embryonic day 12.5 mouse telencephalon. One antibody, monoclonal antibody 25H11, stains predominantly the ventricular zone of the anterior and lateral telencephalon. Purification of the 25H11 antigen, a 47 kDa integral membrane protein, from approximately 2500 mouse telencephali reveals its identity with ephrin B1. Ephrin B1 appears at the onset of neocortical neurogenesis, being first expressed in neuron-generating neuroepithelial cells and rapidly thereafter in virtually all neuroepithelial cells. Expression of ephrin B1 persists through the period of neocortical neurogenesis and is downregulated thereafter. Ephrin B1 is present on the ventricular as well as basolateral plasma membrane of neuroepithelial cells and exhibits an ventricular-high to pial-low gradient across the ventricular zone. Expression of ephrin B1 is also detected on radial glial cells, extending all the way to their pial endfeet, and on neurons in the mantle/intermediate zone but not in the cortical plate. Our results suggest that ephrin B1, presumably via ephrin-Eph receptor signaling, has a role in neurogenesis. Given the ventricular-to-pial gradient of ephrin B1 on the neuroepithelial cell surface and its known role in cell migration in other systems mediated by its repulsive properties, we propose that ephrin B1 may be involved in the migration of newborn neurons out from the ventricular zone toward the neocortex.
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Nobakht M, Fattahi M, Hoormand M, Milanian I, Rahbar N, Mahmoudian M. A study on the teratogenic and cytotoxic effects of safflower extract. JOURNAL OF ETHNOPHARMACOLOGY 2000; 73:453-459. [PMID: 11090999 DOI: 10.1016/s0378-8741(00)00324-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In recent years, the use of carthami flos (the flowers of Carthamus tinctorius L.) as a coloring and flavoring agent has increased as a food additive in Iran. In order to evaluate its safety, the teratogenic effects of carthami flos on the central nervous system development in mice was investigated. Furthermore, its cytotoxic effect on the rat nervous cell culture was studied to complete safety evaluations. For teratogenic studies, after natural mating, pregnant mice were divided into test and control groups. The groups were treated with different dosage regimens of aqueous carthami flos extract during 0-8 days of gestation. Embryos were then isolated at the 13th gestation day and evaluated for macroscopic, microscopic and morphometric characteristics. The results showed that in higher doses (1.6 and 2 mg/kg/day) the embryos were absorbed, whereas with lower dose (1.2 mg/kg/day) changes in external, internal and longitudinal diameters, open neuropore, changes in cellular orientation and cellular degeneration were observed. The results obtained from cytotoxic assay also demonstrated a concentration-dependent cytotoxic effect of carthami flos extract. It is concluded that the use of carthami flos as a food additive should be reconsidered.
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Affiliation(s)
- M Nobakht
- Department of Histology, Iran University of Medical Sciences, Tehran, Iran
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37
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Affiliation(s)
- H B Sarnat
- Department of Neurology, University of Washington School of Medicine, Seattle, USA.
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Zhadanov AB, Provance DW, Speer CA, Coffin JD, Goss D, Blixt JA, Reichert CM, Mercer JA. Absence of the tight junctional protein AF-6 disrupts epithelial cell-cell junctions and cell polarity during mouse development. Curr Biol 1999; 9:880-8. [PMID: 10469590 DOI: 10.1016/s0960-9822(99)80392-3] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The establishment, maintenance and rearrangement of junctions between epithelial cells are extremely important in many developmental, physiological and pathological processes. AF-6 is a putative Ras effector; it is also a component of tight and adherens junctions, and has been shown to bind both Ras and the tight-junction protein ZO-1. In the mouse, AF-6 is encoded by the Af6 gene. As cell-cell junctions are important in morphogenesis, we generated a null mutation in the murine Af6 locus to test the hypothesis that lack of AF-6 function would cause epithelial abnormalities. RESULTS Although cell-cell junctions are thought to be important in early embryogenesis, homozygous mutant embryos were morphologically indistinguishable from wild-type embryos through 6.5 days post coitum (dpc) and were able to establish all three germ layers. The earliest morphological abnormalities were observed in the embryonic ectoderm of mutant embryos at 7.5 dpc. The length of the most apical cell-cell junctions was reduced, and basolateral surfaces of those cells were separated by multiple gaps. Cells of the embryonic ectoderm were less polarized as assessed by histological criteria and lateral localization of an apical marker. Mutant embryos died by 10 dpc, probably as a result of placental failure. CONCLUSIONS AF-6 is a critical regulator of cell-cell junctions during mouse development. The loss of neuroepithelial polarity in mutants is consistent with a loss of efficacy of the cell-cell junctions that have a critical role in establishing apical/basolateral asymmetry.
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Affiliation(s)
- A B Zhadanov
- McLaughlin Research Institute, 1520 23rd Street South, Great Falls, Montana 59405-4900, USA
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Corbeil D, Röper K, Hannah MJ, Hellwig A, Huttner WB. Selective localization of the polytopic membrane protein prominin in microvilli of epithelial cells - a combination of apical sorting and retention in plasma membrane protrusions. J Cell Sci 1999; 112 ( Pt 7):1023-33. [PMID: 10198284 DOI: 10.1242/jcs.112.7.1023] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Prominin is a recently identified polytopic membrane protein expressed in various epithelial cells, where it is selectively associated with microvilli. When expressed in non-epithelial cells, prominin is enriched in plasma membrane protrusions. This raises the question of whether the selective association of prominin with microvilli in epithelial cells is solely due to its preference for, and stabilization in, plasma membrane protrusions, or is due to both sorting to the apical plasma membrane domain and subsequent enrichment in plasma membrane protrusions. To investigate this question, we have generated stably transfected MDCK cells expressing either full-length or C-terminally truncated forms of mouse prominin. Confocal immunofluorescence and domain-selective cell surface biotinylation experiments on transfected MDCK cells grown on permeable supports demonstrated the virtually exclusive apical localization of prominin at steady state. Pulse-chase experiments in combination with domain-selective cell surface biotinylation showed that newly synthesized prominin was directly targeted to the apical plasma membrane domain. Immunoelectron microscopy revealed that prominin was confined to microvilli rather than the planar region of the apical plasma membrane. Truncation of the cytoplasmic C-terminal tail of prominin impaired neither its apical cell surface expression nor its selective retention in microvilli. Both the apical-specific localization of prominin and its selective retention in microvilli were maintained when MDCK cells were cultured in low-calcium medium, i.e. in the absence of tight junctions. Taken together, our results show that: (i) prominin contains dual targeting information, for direct delivery to the apical plasma membrane domain and for the enrichment in the microvillar subdomain; and (ii) this dual targeting does not require the cytoplasmic C-terminal tail of prominin and still occurs in the absence of tight junctions. The latter observation suggests that entry into, and retention in, plasma membrane protrusions may play an important role in the establishment and maintenance of the apical-basal polarity of epithelial cells.
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Affiliation(s)
- D Corbeil
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, and Department of Neurobiology, University of Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
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