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Kikuta H, Tanaka H, Ozaki T, Ito J, Ma J, Moribe S, Hirano M. Spontaneous differentiation of human induced pluripotent stem cells to odorant-responsive olfactory sensory neurons. Biochem Biophys Res Commun 2024; 719:150062. [PMID: 38740002 DOI: 10.1016/j.bbrc.2024.150062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/06/2024] [Indexed: 05/16/2024]
Abstract
Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells (iPSCs), can differentiate into almost all cell types and are anticipated to have significant applications in the field of regenerative medicine. However, there are no reports of successfully directing iPSCs to become functional olfactory sensory neurons (OSNs) capable of selectively receiving odorant compounds. In this study, we employed dual SMAD inhibition and fibroblast growth factor 8 (FGF-8, reported to dictate olfactory fates) along with N-2 and B-27 supplements in the culture medium to efficiently induce the differentiation of iPSCs into neuronal cells with olfactory function through olfactory placode. Temporal gene expression and expression of OSN-specific markers during differentiation indicated that the expression of olfactory marker proteins and various olfactory receptors (ORs), which are markers of mature OSNs, was observed after approximately one month of differentiation culture, irrespective of the differentiation cues, suggesting differentiation into OSNs. Cells that exhibited specific responses to odorant compounds were identified after administering odorant compounds to differentiated iPSC-derived OSNs. This suggests the spontaneous generation of functional OSNs expressing diverse ORs that respond to odorant compounds from iPSCs.
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Affiliation(s)
- Hirokazu Kikuta
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Hidenori Tanaka
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Takashi Ozaki
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Junji Ito
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan
| | - Jiaju Ma
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Shinya Moribe
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Minoru Hirano
- TOYOTA CENTRAL R&D LABS., INC., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan.
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2
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Yu P, Chen W, Jiang L, Jia Y, Xu X, Shen W, Jin N, Du H. Olfactory dysfunction and the role of stem cells in the regeneration of olfactory neurons. Heliyon 2024; 10:e29948. [PMID: 38694081 PMCID: PMC11058886 DOI: 10.1016/j.heliyon.2024.e29948] [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] [Received: 07/31/2023] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
The prevalence of COVID-19 has drawn increasing attention to olfactory dysfunction among researchers. Olfactory dysfunction manifests in various clinical types, influenced by numerous pathogenic factors. Despite this diversity, the underlying pathogenesis remains largely elusive, contributing to a lack of standardized treatment approaches. However, the potential regeneration of olfactory neurons within the nasal cavity presents a promising avenue for addressing olfactory dysfunction effectively. Our review aims to delve into the current research landscape and treatment modalities concerning olfactory dysfunction, emphasizing etiology, pathogenesis, clinical interventions, and the role of stem cells in regenerating olfactory nerves. Through this comprehensive examination, we aim to provide valuable insights into understanding the onset, progression, and treatment of olfactory dysfunction diseases.
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Affiliation(s)
- Pengju Yu
- Department of Otolaryngology, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Weiguan Chen
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Ling Jiang
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Yufeng Jia
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Xiaoyan Xu
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Weiye Shen
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Ni Jin
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Hongjie Du
- Department of Otolaryngology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
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3
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Jiang HC, Park SJ, Wang IH, Bear DM, Nowlan A, Greer PL. CD20/MS4A1 is a mammalian olfactory receptor expressed in a subset of olfactory sensory neurons that mediates innate avoidance of predators. Nat Commun 2024; 15:3360. [PMID: 38637611 PMCID: PMC11026480 DOI: 10.1038/s41467-024-47698-3] [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: 08/25/2023] [Accepted: 04/05/2024] [Indexed: 04/20/2024] Open
Abstract
The mammalian olfactory system detects and discriminates between millions of odorants to elicit appropriate behavioral responses. While much has been learned about how olfactory sensory neurons detect odorants and signal their presence, how specific innate, unlearned behaviors are initiated in response to ethologically relevant odors remains poorly understood. Here, we show that the 4-transmembrane protein CD20, also known as MS4A1, is expressed in a previously uncharacterized subpopulation of olfactory sensory neurons in the main olfactory epithelium of the murine nasal cavity and functions as a mammalian olfactory receptor that recognizes compounds produced by mouse predators. While wildtype mice avoid these predator odorants, mice genetically deleted of CD20 do not appropriately respond. Together, this work reveals a CD20-mediated odor-sensing mechanism in the mammalian olfactory system that triggers innate behaviors critical for organismal survival.
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Affiliation(s)
- Hao-Ching Jiang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Sung Jin Park
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - I-Hao Wang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Interdisciplinary Graduate Program, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Daniel M Bear
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Wu Tsai Neurosciences Institute, Stanford University, Palo Alto, CA, USA
| | - Alexandra Nowlan
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Paul L Greer
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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4
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Hirota J. Molecular mechanisms of differentiation and class choice of olfactory sensory neurons. Genesis 2024; 62:e23587. [PMID: 38454646 DOI: 10.1002/dvg.23587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/10/2024] [Accepted: 01/29/2024] [Indexed: 03/09/2024]
Abstract
The sense of smell is intricately linked to essential animal behaviors necessary for individual survival and species preservation. During vertebrate evolution, odorant receptors (ORs), responsible for detecting odor molecules, have evolved to adapt to changing environments, transitioning from aquatic to terrestrial habitats and accommodating increasing complex chemical environments. These evolutionary pressures have given rise to the largest gene family in vertebrate genomes. Vertebrate ORs are phylogenetically divided into two major classes; class I and class II. Class I OR genes, initially identified in fish and frog, have persisted across vertebrate species. On the other hand, class II OR genes are unique to terrestrial animals, accounting for ~90% of mammalian OR genes. In mice, each olfactory sensory neuron (OSN) expresses a single functional allele of a single OR gene from either the class I or class II OR repertoire. This one neuron-one receptor rule is established through two sequential steps: specification of OR class and subsequent exclusive OR expression from the corresponding OR class. Consequently, OSNs acquire diverse neuronal identities during the process of OSN differentiation, enabling animals to detect a wide array of odor molecules. This review provides an overview of the OSN differentiation process through which OSN diversity is achieved, primarily using the mouse as a model animal.
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Affiliation(s)
- Junji Hirota
- Department of Life Science and Technology, Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- Center for Integrative Biosciences, Tokyo Institute of Technology, Yokohama, Japan
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5
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Jiang HC, Park SJ, Wang IH, Bear DM, Nowlan A, Greer PL. CD20 is a mammalian odorant receptor expressed in a subset of olfactory sensory neurons that mediates innate avoidance of predators. RESEARCH SQUARE 2023:rs.3.rs-3290152. [PMID: 37790559 PMCID: PMC10543371 DOI: 10.21203/rs.3.rs-3290152/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The mammalian olfactory system detects and discriminates between millions of odorants to elicit appropriate behavioral responses. While much has been learned about how olfactory sensory neurons detect odorants and signal their presence, how specific innate, unlearned behaviors are initiated in response to ethologically relevant odors remains poorly understood. Here, we show that the 4-transmembrane protein CD20, also known as MS4A1, is expressed in a previously uncharacterized subpopulation of olfactory sensory neurons in the main olfactory epithelium of the murine nasal cavity and functions as a mammalian odorant receptor that recognizes compounds produced by mouse predators. While wild-type mice avoid these predator odorants, mice genetically deleted of CD20 do not appropriately respond. Together, this work reveals a novel CD20-mediated odor-sensing mechanism in the mammalian olfactory system that triggers innate behaviors critical for organismal survival.
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Affiliation(s)
- Hao-Ching Jiang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Sung Jin Park
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - I-Hao Wang
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Interdisciplinary Graduate Program, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Daniel M Bear
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Current Affiliation: Wu Tsai Neurosciences Institute, Stanford University, Palo Alto, CA, USA
| | - Alexandra Nowlan
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Current affiliation: Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Paul L Greer
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
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Jiang HC, Park SJ, Wang IH, Bear DM, Nowlan A, Greer PL. CD20 is a mammalian odorant receptor expressed in a subset of olfactory sensory neurons that mediates innate avoidance of predators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552498. [PMID: 37609248 PMCID: PMC10441374 DOI: 10.1101/2023.08.08.552498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The mammalian olfactory system detects and discriminates between millions of odorants to elicit appropriate behavioral responses. While much has been learned about how olfactory sensory neurons detect odorants and signal their presence, how specific innate, unlearned behaviors are initiated in response to ethologically relevant odors remains poorly understood. Here, we show that the 4-transmembrane protein CD20, also known as MS4A1, is expressed in a previously uncharacterized subpopulation of olfactory sensory neurons in the main olfactory epithelium of the murine nasal cavity and functions as a mammalian odorant receptor that recognizes compounds produced by mouse predators. While wild-type mice avoid these predator odorants, mice genetically deleted of CD20 do not appropriately respond. Together, this work reveals a novel CD20-mediated odor-sensing mechanism in the mammalian olfactory system that triggers innate behaviors critical for organismal survival.
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7
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Louie JD, Bromberg BH, Zunitch MJ, Schwob JE. Horizontal basal cells self-govern their neurogenic potential during injury-induced regeneration of the olfactory epithelium. Development 2023; 150:dev201552. [PMID: 37260223 PMCID: PMC10323233 DOI: 10.1242/dev.201552] [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: 12/22/2022] [Accepted: 05/18/2023] [Indexed: 06/02/2023]
Abstract
Horizontal basal cells (HBCs) residing within severely damaged olfactory epithelium (OE) mediate OE regeneration by differentiating into odorant-detecting olfactory sensory neurons (OSNs) and other tissue supporting non-neuronal cell types. Depending on both tissue type and integrity, the Notch signaling pathway can either positively or negatively regulate resident stem cell activity. Although Notch1 specifies HBC dormancy in the uninjured OE, little is known about how HBCs are influenced by the Notch pathway following OE injury. Here, we show that HBCs depend on a functional inversion of the Notch pathway to appropriately mediate OE regeneration. At 24 h post-injury, HBCs enhance Notch1-mediated signaling. Moreover, at 3 days post-injury when the regenerating OE is composed of multiple cell layers, HBCs enrich both Notch1 and the Notch ligand, Dll1. Notably, HBC-specific Notch1 knockout increases HBC quiescence and impairs HBC differentiation into neuronal progenitors and OSNs. Interestingly, complete HBC knockout of Dll1 only decreases differentiation of HBC-derived OSNs. These data underscore the context-dependent nature of Notch signaling. Furthermore, they reveal that HBCs regulate their own neurogenic potential after OE injury.
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Affiliation(s)
- Jonathan D. Louie
- Medical Scientist Training Program, Tufts University School of Medicine, Boston, MA 02111, USA
- Neuroscience Graduate Program, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
- Department of Developmental, Molecular and Chemical Biology, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
| | - Benjamin H. Bromberg
- Department of Developmental, Molecular and Chemical Biology, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
| | - Matthew J. Zunitch
- Medical Scientist Training Program, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Developmental, Molecular and Chemical Biology, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
- Cell, Molecular and Developmental Biology Graduate Program, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
| | - James E. Schwob
- Department of Developmental, Molecular and Chemical Biology, Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
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8
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Zunitch MJ, Fisch AS, Lin B, Barrios-Camacho CM, Faquin WC, Tachie-Baffour Y, Louie JD, Jang W, Curry WT, Gray ST, Lin DT, Schwob JE, Holbrook EH. Molecular Evidence for Olfactory Neuroblastoma as a Tumor of Malignant Globose Basal Cells. Mod Pathol 2023; 36:100122. [PMID: 36841178 PMCID: PMC10198888 DOI: 10.1016/j.modpat.2023.100122] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
Olfactory neuroblastoma (ONB, esthesioneuroblastoma) is a sinonasal cancer with an underdeveloped diagnostic toolkit, and is the subject of many incidents of tumor misclassification throughout the literature. Despite its name, connections between the cancer and normal cells of the olfactory epithelium have not been systematically explored and markers of olfactory epithelial cell types are not deployed in clinical practice. Here, we utilize an integrated human-mouse single-cell atlas of the nasal mucosa, including the olfactory epithelium, to identify transcriptomic programs that link ONB to a specific population of stem/progenitor cells known as olfactory epithelial globose basal cells (GBCs). Expression of a GBC transcription factor NEUROD1 distinguishes both low- and high-grade ONB from sinonasal undifferentiated carcinoma, a potential histologic mimic with a distinctly unfavorable prognosis. Furthermore, we identify a reproducible subpopulation of highly proliferative ONB cells expressing the GBC stemness marker EZH2, suggesting that EZH2 inhibition may play a role in the targeted treatment of ONB. Finally, we study the cellular states comprising ONB parenchyma using single-cell transcriptomics and identify evidence of a conserved GBC transcriptional regulatory circuit that governs divergent neuronal-versus-sustentacular differentiation. These results link ONB to a specific cell type for the first time and identify conserved developmental pathways within ONB that inform diagnostic, prognostic, and mechanistic investigation.
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Affiliation(s)
- Matthew J Zunitch
- Medical Scientist Training Program, Tufts University School of Medicine, Boston, Massachusetts; Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts
| | - Adam S Fisch
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brian Lin
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - William C Faquin
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yaw Tachie-Baffour
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts
| | - Jonathan D Louie
- Medical Scientist Training Program, Tufts University School of Medicine, Boston, Massachusetts; Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
| | - Woochan Jang
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts
| | - William T Curry
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Stacey T Gray
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Derrick T Lin
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - James E Schwob
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts; Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts.
| | - Eric H Holbrook
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts.
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Paronett EM, Bryan CA, Maynard TM, LaMantia AS. Identity, lineage and fates of a temporally distinct progenitor population in the embryonic olfactory epithelium. Dev Biol 2023; 495:76-91. [PMID: 36627077 PMCID: PMC9926479 DOI: 10.1016/j.ydbio.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/29/2022] [Accepted: 01/01/2023] [Indexed: 01/09/2023]
Abstract
We defined a temporally and transcriptionally divergent precursor cohort in the medial olfactory epithelium (OE) shortly after it differentiates as a distinct tissue at mid-gestation in the mouse. This temporally distinct population of Ascl1+ cells in the dorsomedial OE is segregated from Meis1+/Pax7+ progenitors in the lateral OE, and does not appear to be generated by Pax7+ lateral OE precursors. The medial Ascl1+ precursors do not yield a substantial number of early-generated ORNs. Instead, they first generate additional proliferative precursors as well as a distinct population of frontonasal mesenchymal cells associated with the migratory mass that surrounds the nascent olfactory nerve. Parallel to these in vivo distinctions, isolated medial versus lateral OE precursors in vitro retain distinct proliferative capacities and modes of division that reflect their in vivo identities. At later fetal stages, these early dorsomedial Ascl1+ precursors cells generate spatially restricted subsets of ORNs as well as other non-neuronal cell classes. Accordingly, the initial compliment of ORNs and other OE cell types is derived from at least two distinct early precursor populations: lateral Meis1/Pax7+ precursors that generate primarily early ORNs, and a temporally, spatially, and transcriptionally distinct subset of medial Ascl1+ precursors that initially generate additional OE progenitors and apparent migratory mass cells before yielding a subset of ORNs and likely supporting cell classes.
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Affiliation(s)
- Elizabeth M Paronett
- Department of Pharmacology and Physiology, George Washington University School of Medicine, Washington, DC, 20037, USA
| | - Corey A Bryan
- Laboratory of Developmental Disorders and Genetics, The Fralin Biomedical Research Institute, Virginia Tech-Carilion School of Medicine, Roanoke, VA, USA
| | - Thomas M Maynard
- Center for Neurobiology Research, The Fralin Biomedical Research Institute, Virginia Tech-Carilion School of Medicine, Roanoke, VA, USA
| | - Anthony-S LaMantia
- Center for Neurobiology Research, The Fralin Biomedical Research Institute, Virginia Tech-Carilion School of Medicine, Roanoke, VA, USA; Department of Biological Sciences Virginia Tech, Blacksburg, VA, USA.
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Wang Y, Madhusudan S, Cotellessa L, Kvist J, Eskici N, Yellapragada V, Pulli K, Lund C, Vaaralahti K, Tuuri T, Giacobini P, Raivio T. Deciphering the Transcriptional Landscape of Human Pluripotent Stem Cell-Derived GnRH Neurons: The Role of Wnt Signaling in Patterning the Neural Fate. Stem Cells 2022; 40:1107-1121. [PMID: 36153707 PMCID: PMC9806769 DOI: 10.1093/stmcls/sxac069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/14/2022] [Indexed: 01/05/2023]
Abstract
Hypothalamic gonadotropin-releasing hormone (GnRH) neurons lay the foundation for human development and reproduction; however, the critical cell populations and the entangled mechanisms underlying the development of human GnRH neurons remain poorly understood. Here, by using our established human pluripotent stem cell-derived GnRH neuron model, we decoded the cellular heterogeneity and differentiation trajectories at the single-cell level. We found that a glutamatergic neuron population, which generated together with GnRH neurons, showed similar transcriptomic properties with olfactory sensory neuron and provided the migratory path for GnRH neurons. Through trajectory analysis, we identified a specific gene module activated along the GnRH neuron differentiation lineage, and we examined one of the transcription factors, DLX5, expression in human fetal GnRH neurons. Furthermore, we found that Wnt inhibition could increase DLX5 expression and improve the GnRH neuron differentiation efficiency through promoting neurogenesis and switching the differentiation fates of neural progenitors into glutamatergic neurons/GnRH neurons. Our research comprehensively reveals the dynamic cell population transition and gene regulatory network during GnRH neuron differentiation.
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Affiliation(s)
- Yafei Wang
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Shrinidhi Madhusudan
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Ludovica Cotellessa
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Postnatal Brain, Lille Neuroscience & Cognition, UMR-S1172, Lille, France
| | - Jouni Kvist
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Nazli Eskici
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Venkatram Yellapragada
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kristiina Pulli
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Carina Lund
- Folkhälsan Research Center, Helsinki, Finland
| | - Kirsi Vaaralahti
- Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland,New Children’s Hospital, Pediatric Research Center, Helsinki University Hospital, Helsinki, Finland
| | - Timo Tuuri
- Department of Obstetrics and Gynecology, Helsinki University Hospital, Helsinki, Finland
| | | | - Taneli Raivio
- Corresponding author: Taneli Raivio, Stem Cells and Metabolism Research Program, Research Programs Unit, and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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11
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Katreddi RR, Taroc EZM, Hicks SM, Lin JM, Liu S, Xiang M, Forni PE. Notch signaling determines cell-fate specification of the two main types of vomeronasal neurons of rodents. Development 2022; 149:dev200448. [PMID: 35781337 PMCID: PMC9340558 DOI: 10.1242/dev.200448] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 06/15/2022] [Indexed: 01/09/2023]
Abstract
The ability of terrestrial vertebrates to find food and mating partners, and to avoid predators, relies on the detection of chemosensory information. Semiochemicals responsible for social and sexual behaviors are detected by chemosensory neurons of the vomeronasal organ (VNO), which transmits information to the accessory olfactory bulb. The vomeronasal sensory epithelium of most mammalian species contains a uniform vomeronasal system; however, rodents and marsupials have developed a more complex binary vomeronasal system, containing vomeronasal sensory neurons (VSNs) expressing receptors of either the V1R or V2R family. In rodents, V1R/apical and V2R/basal VSNs originate from a common pool of progenitors. Using single cell RNA-sequencing, we identified differential expression of Notch1 receptor and Dll4 ligand between the neuronal precursors at the VSN differentiation dichotomy. Our experiments show that Notch signaling is required for effective differentiation of V2R/basal VSNs. In fact, Notch1 loss of function in neuronal progenitors diverts them to the V1R/apical fate, whereas Notch1 gain of function redirects precursors to V2R/basal. Our results indicate that Notch signaling plays a pivotal role in triggering the binary differentiation dichotomy in the VNO of rodents.
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Affiliation(s)
- Raghu Ram Katreddi
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Ed Zandro M. Taroc
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Sawyer M. Hicks
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Jennifer M. Lin
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Shuting Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Paolo E. Forni
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
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12
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Filova I, Bohuslavova R, Tavakoli M, Yamoah EN, Fritzsch B, Pavlinkova G. Early Deletion of Neurod1 Alters Neuronal Lineage Potential and Diminishes Neurogenesis in the Inner Ear. Front Cell Dev Biol 2022; 10:845461. [PMID: 35252209 PMCID: PMC8894106 DOI: 10.3389/fcell.2022.845461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal development in the inner ear is initiated by expression of the proneural basic Helix-Loop-Helix (bHLH) transcription factor Neurogenin1 that specifies neuronal precursors in the otocyst. The initial specification of the neuroblasts within the otic epithelium is followed by the expression of an additional bHLH factor, Neurod1. Although NEUROD1 is essential for inner ear neuronal development, the different aspects of the temporal and spatial requirements of NEUROD1 for the inner ear and, mainly, for auditory neuron development are not fully understood. In this study, using Foxg1Cre for the early elimination of Neurod1 in the mouse otocyst, we showed that Neurod1 deletion results in a massive reduction of differentiating neurons in the otic ganglion at E10.5, and in the diminished vestibular and rudimental spiral ganglia at E13.5. Attenuated neuronal development was associated with reduced and disorganized sensory epithelia, formation of ectopic hair cells, and the shortened cochlea in the inner ear. Central projections of inner ear neurons with conditional Neurod1 deletion are reduced, unsegregated, disorganized, and interconnecting the vestibular and auditory systems. In line with decreased afferent input from auditory neurons, the volume of cochlear nuclei was reduced by 60% in Neurod1 mutant mice. Finally, our data demonstrate that early elimination of Neurod1 affects the neuronal lineage potential and alters the generation of inner ear neurons and cochlear afferents with a profound effect on the first auditory nuclei, the cochlear nuclei.
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Affiliation(s)
- Iva Filova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Romana Bohuslavova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Mitra Tavakoli
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, Institute for Neuroscience, University of Nevada, Reno, NV, United States
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
- *Correspondence: Gabriela Pavlinkova,
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13
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Joseph KB, Awadallah N, Delay ER, Delay RJ. Transient Effects of Cyclophosphamide on Basal Cell Proliferation of Olfactory Epithelia. Chem Senses 2021; 45:549-561. [PMID: 32531016 DOI: 10.1093/chemse/bjaa039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cancer is often treated with broad-spectrum cytotoxic drugs that not only eradicate cancerous cells but also have detrimental side effects. One of these side effects, disruption of the olfactory system, impedes a patient's ability to smell, perceive flavor, and ultimately may interfere with their nutritional intake and recovery from cancer. Recent studies reported that the chemotherapy drug, cyclophosphamide (CYP), can damage gustatory epithelia and disrupt cell proliferation in olfactory epithelia. In this study, we asked if CYP altered globose and horizontal basal cell proliferation in the murine main olfactory epithelium (MOE) and vomeronasal organ (VNO). We used antibodies for Ki67, a marker strictly associated with cell proliferation, and Keratin 5, a marker for the cytoskeleton of horizontal basal cells. Our results revealed a significant CYP-induced decrease in the number of proliferative cells in both epithelia, especially globose basal cells in the MOE, within the first 1-2 days postinjection. Recovery of cell renewal was apparent 6 days after injection. The immunohistochemical markers showed significantly higher levels of globose and horizontal basal cell proliferation in CYP-injected mice at 14 and 30 days postinjection compared with control mice. The prolonged proliferative activation of globose and horizontal basal cells suggests that, besides altering proliferation of olfactory epithelia, the epithelial substrate needed for successful cell renewal may be adversely affected by CYP.
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Affiliation(s)
- Kyle B Joseph
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, VT, USA.,Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA
| | - Nora Awadallah
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, VT, USA.,City University of New York (CUNY) Neuroscience Collaborative, CUNY Graduate Center, New York City, NY, USA.,Department of Molecular, Cellular and Biomedical Sciences, The CUNY School of Medicine, City College, The City University of New York, New York City, NY, USA
| | - Eugene R Delay
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, VT, USA
| | - Rona J Delay
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, VT, USA
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14
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Katreddi RR, Forni PE. Mechanisms underlying pre- and postnatal development of the vomeronasal organ. Cell Mol Life Sci 2021; 78:5069-5082. [PMID: 33871676 PMCID: PMC8254721 DOI: 10.1007/s00018-021-03829-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/17/2021] [Accepted: 03/29/2021] [Indexed: 02/06/2023]
Abstract
The vomeronasal organ (VNO) is sensory organ located in the ventral region of the nasal cavity in rodents. The VNO develops from the olfactory placode during the secondary invagination of olfactory pit. The embryonic vomeronasal structure appears as a neurogenic area where migratory neuronal populations like endocrine gonadotropin-releasing hormone-1 (GnRH-1) neurons form. Even though embryonic vomeronasal structures are conserved across most vertebrate species, many species including humans do not have a functional VNO after birth. The vomeronasal epithelium (VNE) of rodents is composed of two major types of vomeronasal sensory neurons (VSNs): (1) VSNs distributed in the apical VNE regions that express vomeronasal type-1 receptors (V1Rs) and the G protein subunit Gαi2, and (2) VSNs in the basal territories of the VNE that express vomeronasal type-2 receptors (V2Rs) and the G subunit Gαo. Recent studies identified a third subclass of Gαi2 and Gαo VSNs that express the formyl peptide receptor family. VSNs expressing V1Rs or V2Rs send their axons to distinct regions of the accessory olfactory bulb (AOB). Together, VNO and AOB form the accessory olfactory system (AOS), an olfactory subsystem that coordinates the social and sexual behaviors of many vertebrate species. In this review, we summarize our current understanding of cellular and molecular mechanisms that underlie VNO development. We also discuss open questions for study, which we suggest will further enhance our understanding of VNO morphogenesis at embryonic and postnatal stages.
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Affiliation(s)
- Raghu Ram Katreddi
- Department of Biological Sciences, Center for Neuroscience Research, The RNA Institute, University At Albany, State University of New York, Albany, NY, USA
| | - Paolo E Forni
- Department of Biological Sciences, Center for Neuroscience Research, The RNA Institute, University At Albany, State University of New York, Albany, NY, USA.
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15
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Abstract
Olfactory sensory neurons (OSNs) are bipolar neurons, unusual because they turn over continuously and have a multiciliated dendrite. The extensive changes in gene expression accompanying OSN differentiation in mice are largely known, especially the transcriptional regulators responsible for altering gene expression, revealing much about how differentiation proceeds. Basal progenitor cells of the olfactory epithelium transition into nascent OSNs marked by Cxcr4 expression and the initial extension of basal and apical neurites. Nascent OSNs become immature OSNs within 24-48 h. Immature OSN differentiation requires about a week and at least 2 stages. Early-stage immature OSNs initiate expression of genes encoding key transcriptional regulators and structural proteins necessary for further neuritogenesis. Late-stage immature OSNs begin expressing genes encoding proteins important for energy production and neuronal homeostasis that carry over into mature OSNs. The transition to maturity depends on massive expression of one allele of one odorant receptor gene, and this results in expression of the last 8% of genes expressed by mature OSNs. Many of these genes encode proteins necessary for mature function of axons and synapses or for completing the elaboration of non-motile cilia, which began extending from the newly formed dendritic knobs of immature OSNs. The cilia from adjoining OSNs form a meshwork in the olfactory mucus and are the site of olfactory transduction. Immature OSNs also have a primary cilium, but its role is unknown, unlike the critical role in proliferation and differentiation played by the primary cilium of the olfactory epithelium's horizontal basal cell.
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Affiliation(s)
- Timothy S McClintock
- Department of Physiology, University of Kentucky, Lexington, KY, USA
- Correspondence to be sent to: Timothy S. McClintock, Department of Physiology, University of Kentucky, 800 Rose St., Lexington, KY 40536-0298, USA. e-mail:
| | - Naazneen Khan
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Chao Xie
- Department of Pharmacology and Therapeutics, and Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, and Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
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16
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Ching K, Stearns T. Centrioles are amplified in cycling progenitors of olfactory sensory neurons. PLoS Biol 2020; 18:e3000852. [PMID: 32931487 PMCID: PMC7518617 DOI: 10.1371/journal.pbio.3000852] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/25/2020] [Accepted: 08/20/2020] [Indexed: 11/19/2022] Open
Abstract
Olfaction in most animals is mediated by neurons bearing cilia that are accessible to the environment. Olfactory sensory neurons (OSNs) in chordates usually have multiple cilia, each with a centriole at its base. OSNs differentiate from stem cells in the olfactory epithelium, and how the epithelium generates cells with many centrioles is not yet understood. We show that centrioles are amplified via centriole rosette formation in both embryonic development and turnover of the olfactory epithelium in adult mice, and rosette-bearing cells often have free centrioles in addition. Cells with amplified centrioles can go on to divide, with centrioles clustered at each pole. Additionally, we found that centrioles are amplified in immediate neuronal precursors (INPs) concomitant with elevation of mRNA for polo-like kinase 4 (Plk4) and SCL/Tal1-interrupting locus gene (Stil), key regulators of centriole duplication. These results support a model in which centriole amplification occurs during a transient state characterized by elevated Plk4 and Stil in early INP cells. These cells then go on to divide at least once to become OSNs, demonstrating that cell division with amplified centrioles, known to be tolerated in disease states, can occur as part of a normal developmental program.
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Affiliation(s)
- Kaitlin Ching
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Tim Stearns
- Department of Biology, Stanford University, Stanford, California, United States of America
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
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17
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Awadallah N, Proctor K, Joseph KB, Delay ER, Delay RJ. Cyclophosphamide has Long-Term Effects on Proliferation in Olfactory Epithelia. Chem Senses 2020; 45:97-109. [PMID: 31844905 PMCID: PMC7446702 DOI: 10.1093/chemse/bjz075] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Chemotherapy patients often experience chemosensory changes during and after drug therapy. The chemotherapy drug, cyclophosphamide (CYP), has known cytotoxic effects on sensory and proliferating cells of the taste system. Like the taste system, cells in the olfactory epithelia undergo continuous renewal. Therefore, we asked if a single injection of 75 mg/kg CYP would affect cell proliferation in the anterior dorsomedial region of the main olfactory epithelium (MOE) and the vomeronasal organ (VNO) from 0 to 125 days after injection. Both epithelia showed a decrease in Ki67-labeled cells compared to controls at day 1 and no Ki67+ cells at day 2 postinjection. In the sensory layer of the MOE, cell proliferation began to recover 4 days after CYP injection and by 6 days, the rate of proliferation was significantly greater than controls. Ki67+ cells peaked 30 days postinjection, then declined to control levels at day 45. Similar temporal sequences of initial CYP-induced suppression of cell proliferation followed by elevated rates peaking 30-45 days postinjection were seen in the sustentacular layer of the MOE and all 3 areas (sensory, sustentacular, marginal) of the VNO. CYP affected proliferation in the sensory layer of the MOE more than the sustentacular layer and all 3 areas of the VNO. These findings suggest that chemotherapy involving CYP is capable of affecting cell renewal of the olfactory system and likely contributes to clinical loss of function during and after chemotherapy.
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Affiliation(s)
- Nora Awadallah
- Neuroscience Program, Marsh Life Science, University of Vermont, Burlington, USA
| | - Kara Proctor
- Department of Biomedical and Health Sciences, University of Vermont, Burlington, USA
| | - Kyle B Joseph
- Department of Biology, Marsh Life Science, University of Vermont, Burlington, USA
| | - Eugene R Delay
- Neuroscience Program, Marsh Life Science, University of Vermont, Burlington, USA
- Department of Biology, Marsh Life Science, University of Vermont, Burlington, USA
| | - Rona J Delay
- Neuroscience Program, Marsh Life Science, University of Vermont, Burlington, USA
- Department of Biology, Marsh Life Science, University of Vermont, Burlington, USA
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18
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Kim JS, Kim BG. Neurogenesis and Regulation of Olfactory Epithelium. JOURNAL OF RHINOLOGY 2019. [DOI: 10.18787/jr.2019.26.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Ji-Sun Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Eunpyeong St. Mar's, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Byung Guk Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Eunpyeong St. Mar's, College of Medicine, The Catholic University of Korea, Seoul, Korea
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19
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Spatial Determination of Neuronal Diversification in the Olfactory Epithelium. J Neurosci 2018; 39:814-832. [PMID: 30530861 DOI: 10.1523/jneurosci.3594-17.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 11/21/2018] [Accepted: 11/23/2018] [Indexed: 01/31/2023] Open
Abstract
Neurons in the murine olfactory epithelium (OE) differ by the olfactory receptor they express as well as other molecular phenotypes that are regionally restricted. These patterns can be precisely regenerated following epithelial injury, suggesting that spatial cues within the tissue can direct neuronal diversification. Nonetheless, the permanency and mechanism of this spatial patterning remain subject to debate. Via transplantation of stem and progenitor cells from dorsal OE into ventral OE, we demonstrate that, in mice of both sexes, nonautonomous spatial cues can direct the spatially circumscribed differentiation of olfactory sensory neurons. The vast majority of dorsal transplant-derived neurons express the ventral marker OCAM (NCAM2) and lose expression of NQO1 to match their new location. Single-cell analysis also demonstrates that OSNs adopt a fate defined by their new position following progenitor cell transplant, such that a ventral olfactory receptor is expressed after stem and progenitor cell engraftment. Thus, spatially constrained differentiation of olfactory sensory neurons is plastic, and any bias toward an epigenetic memory of place can be overcome.SIGNIFICANCE STATEMENT Spatially restricted differentiation of olfactory sensory neurons is both key to normal olfactory function and a challenging example of biological specificity. That the stem cells of the olfactory epithelium reproduce the organization of the olfactory periphery to a very close approximation during lesion-induced regeneration begs the question of whether stem cell-autonomous genomic architecture or environmental cues are responsible. The plasticity demonstrated after transfer to a novel location suggests that cues external to the transplanted stem and progenitor cells confer neuronal identity. Thus, a necessary prerequisite is satisfied for using engraftment of olfactory stem and progenitor cells as a cellular therapeutic intervention to reinvigorate neurogenesis whose exhaustion contributes to the waning of olfaction with age.
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20
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Canonical Notch Signaling Directs the Fate of Differentiating Neurocompetent Progenitors in the Mammalian Olfactory Epithelium. J Neurosci 2018; 38:5022-5037. [PMID: 29739871 DOI: 10.1523/jneurosci.0484-17.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/31/2018] [Accepted: 05/04/2018] [Indexed: 12/24/2022] Open
Abstract
The adult olfactory epithelium (OE) has the remarkable capacity to regenerate fully both neurosensory and non-neuronal cell types after severe epithelial injury. Lifelong persistence of two stem cell populations supports OE regeneration when damaged: the horizontal basal cells (HBCs), dormant and held in reserve; and globose basal cells, a heterogeneous population most of which are actively dividing. Both populations regenerate all cell types of the OE after injury, but the mechanisms underlying neuronal versus non-neuronal lineage commitment after recruitment of the stem cell pools remains unknown. We used both retroviral transduction and mouse lines that permit conditional cell-specific genetic manipulation as well as the tracing of progeny to study the role of canonical Notch signaling in the determination of neuronal versus non-neuronal lineages in the regenerating adult OE. Excision of either Notch1 or Notch2 genes alone in HBCs did not alter progenitor fate during recovery from epithelial injury, whereas conditional knock-out of both Notch1 and Notch2 together, retroviral transduction of progenitors with a dominant-negative form of MAML (mastermind-like), or excision of the downstream cofactor RBPJ caused progeny to adopt a neuronal fate exclusively. Conversely, we show that overexpressing the Notch1-intracellular domain (N1ICD) either genetically or by transduction blocks neuronal differentiation completely. However, N1ICD overexpression requires both alleles of the canonical cofactor RBPJ to specify downstream lineage. Together, our results suggest that canonical RBPJ-dependent Notch signaling through redundant Notch1 and Notch2 receptors is both necessary and sufficient for determining neuronal versus non-neuronal differentiation in the regenerating adult OE.SIGNIFICANCE STATEMENT Despite the substantial reconstitution of the olfactory epithelium and its population of sensory neurons after injury, disruption and exhaustion of neurogenesis is a consequence of aging and a cause of olfactory dysfunction. Understanding the mechanisms underlying the generation of replacement neurons and non-neuronal cells is critical to any therapeutic strategy aimed at rebuilding a functional neuroepithelium. The results shown here demonstrate that canonical Notch signaling determines the balance between neurons and non-neuronal cells during restoration of the epithelium after injury. Moreover, the complexities of the multiple Notch pathways impinging on that decision are dissected in detail. Finally, RBPJ, the canonical Notch transcriptional cofactor, exhibits a heretofore unreported haploinsufficiency in setting the balance among the regenerating populations.
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21
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Sokpor G, Abbas E, Rosenbusch J, Staiger JF, Tuoc T. Transcriptional and Epigenetic Control of Mammalian Olfactory Epithelium Development. Mol Neurobiol 2018. [PMID: 29532253 DOI: 10.1007/s12035-018-0987-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The postnatal mammalian olfactory epithelium (OE) represents a major aspect of the peripheral olfactory system. It is a pseudostratified tissue that originates from the olfactory placode and is composed of diverse cells, some of which are specialized receptor neurons capable of transducing odorant stimuli to afford the perception of smell (olfaction). The OE is known to offer a tractable miniature model for studying the systematic generation of neurons and glia that typify neural tissue development. During OE development, stem/progenitor cells that will become olfactory sensory neurons and/or non-neuronal cell types display fine spatiotemporal expression of neuronal and non-neuronal genes that ensures their proper proliferation, differentiation, survival, and regeneration. Many factors, including transcription and epigenetic factors, have been identified as key regulators of the expression of such requisite genes to permit normal OE morphogenesis. Typically, specific interactive regulatory networks established between transcription and epigenetic factors/cofactors orchestrate histogenesis in the embryonic and adult OE. Hence, investigation of these regulatory networks critical for OE development promises to disclose strategies that may be employed in manipulating the stepwise transition of olfactory precursor cells to become fully differentiated and functional neuronal and non-neuronal cell types. Such strategies potentially offer formidable means of replacing injured or degenerated neural cells as therapeutics for nervous system perturbations. This review recapitulates the developmental cellular diversity of the olfactory neuroepithelium and discusses findings on how the precise and cooperative molecular control by transcriptional and epigenetic machinery is indispensable for OE ontogeny.
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Affiliation(s)
- Godwin Sokpor
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Eman Abbas
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Joachim Rosenbusch
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany
| | - Jochen F Staiger
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany
| | - Tran Tuoc
- Institute of Neuroanatomy, University Medical Center, Georg-August-University Goettingen, 37075, Goettingen, Germany. .,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075, Goettingen, Germany.
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22
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Panaliappan TK, Wittmann W, Jidigam VK, Mercurio S, Bertolini JA, Sghari S, Bose R, Patthey C, Nicolis SK, Gunhaga L. Sox2 is required for olfactory pit formation and olfactory neurogenesis through BMP restriction and Hes5 upregulation. Development 2018; 145:145/2/dev153791. [PMID: 29352015 PMCID: PMC5825848 DOI: 10.1242/dev.153791] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 12/11/2017] [Indexed: 12/26/2022]
Abstract
The transcription factor Sox2 is necessary to maintain pluripotency of embryonic stem cells, and to regulate neural development. Neurogenesis in the vertebrate olfactory epithelium persists from embryonic stages through adulthood. The role Sox2 plays for the development of the olfactory epithelium and neurogenesis within has, however, not been determined. Here, by analysing Sox2 conditional knockout mouse embryos and chick embryos deprived of Sox2 in the olfactory epithelium using CRISPR-Cas9, we show that Sox2 activity is crucial for the induction of the neural progenitor gene Hes5 and for subsequent differentiation of the neuronal lineage. Our results also suggest that Sox2 activity promotes the neurogenic domain in the nasal epithelium by restricting Bmp4 expression. The Sox2-deficient olfactory epithelium displays diminished cell cycle progression and proliferation, a dramatic increase in apoptosis and finally olfactory pit atrophy. Moreover, chromatin immunoprecipitation data show that Sox2 directly binds to the Hes5 promoter in both the PNS and CNS. Taken together, our results indicate that Sox2 is essential to establish, maintain and expand the neuronal progenitor pool by suppressing Bmp4 and upregulating Hes5 expression. Summary: Analysis of Sox2 mutant mouse and Sox2 CRISPR-targeted chick embryos reveals that Sox2 controls the establishment of sensory progenitors in the olfactory epithelium by suppressing Bmp4 and upregulating Hes5 expression.
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Affiliation(s)
| | - Walter Wittmann
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Vijay K Jidigam
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Sara Mercurio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Jessica A Bertolini
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Soufien Sghari
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Raj Bose
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Cedric Patthey
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Silvia K Nicolis
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Lena Gunhaga
- Umeå Centre for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
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23
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Lin B, Coleman JH, Peterson JN, Zunitch MJ, Jang W, Herrick DB, Schwob JE. Injury Induces Endogenous Reprogramming and Dedifferentiation of Neuronal Progenitors to Multipotency. Cell Stem Cell 2017; 21:761-774.e5. [PMID: 29174332 DOI: 10.1016/j.stem.2017.09.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/12/2017] [Accepted: 09/12/2017] [Indexed: 02/08/2023]
Abstract
Adult neurogenesis in the olfactory epithelium is often depicted as a unidirectional pathway during homeostasis and repair. We challenge the unidirectionality of this model by showing that epithelial injury unlocks the potential for Ascl1+ progenitors and Neurog1+ specified neuronal precursors to dedifferentiate into multipotent stem/progenitor cells that contribute significantly to tissue regeneration in the murine olfactory epithelium (OE). We characterize these dedifferentiating cells using several lineage-tracing strains and single-cell mRNA-seq, and we show that Sox2 is required for initiating dedifferentiation and that inhibition of Ezh2 promotes multipotent progenitor expansion. These results suggest that the apparent hierarchy of neuronal differentiation is not irreversible and that lineage commitment can be overridden following severe tissue injury. We elucidate a previously unappreciated pathway for endogenous tissue repair by a highly regenerative neuroepithelium and introduce a system to study the mechanisms underlying plasticity in the OE that can be adapted for other tissues.
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Affiliation(s)
- Brian Lin
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA; Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Julie H Coleman
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA; Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Jesse N Peterson
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA; Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Matthew J Zunitch
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA; Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Woochan Jang
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA
| | - Daniel B Herrick
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA; Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - James E Schwob
- Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, Boston, MA 02111, USA.
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24
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Kurtenbach S, Ding W, Goss GM, Hare JM, Goldstein BJ, Shehadeh LA. Differential expression of microRNAs among cell populations in the regenerating adult mouse olfactory epithelium. PLoS One 2017; 12:e0187576. [PMID: 29107942 PMCID: PMC5673187 DOI: 10.1371/journal.pone.0187576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/23/2017] [Indexed: 01/01/2023] Open
Abstract
Despite a robust capacity for adult neurogenesis in the olfactory epithelium (OE), olfactory sensory losses are common. Identification of mechanisms regulating adult OE neurogenesis is, therefore, of interest. MicroRNAs (miRNAs) are broadly important in regulating vertebrate neurodevelopment, and are required in embryonic olfactory differentiation. We report here that a panel of miRNAs is differentially expressed by either progenitor or progeny cells in the regenerating mouse OE. Progenitor cells were purified from lesioned OE based on c-Kit expression, and miRNA expression was assayed in c-Kit (+) and c-Kit (-) cell populations. 28 miRNAs were significantly downregulated by at least 4 fold in the c-Kit (+) fraction, which marks the globose basal progenitor cell population. In addition, 10 miRNAs were upregulated in these basal cells. MiR-486, the most strongly downregulated miRNA identified, was further characterized to verify results. MiR-486 expression was confirmed in the c-Kit (-) OE layers using in situ hybridization. As a functional assay, over-expression of miR-486 in purified c-Kit (+) basal cell cultures resulted in a reduction in neurogenesis, consistent with a possible negative feedback regulatory model. Our data provide new insights regarding miRNA expression and function during adult OE neurogenesis, and identify candidate miRNAs warranting further study.
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Affiliation(s)
- Sarah Kurtenbach
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Otolaryngology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
| | - Wen Ding
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
| | - Garrett M. Goss
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Otolaryngology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
| | - Joshua M. Hare
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Medicine, Division of Cardiology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
| | - Bradley J. Goldstein
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Otolaryngology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- * E-mail: (BG); (LS)
| | - Lina A. Shehadeh
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Department of Medicine, Division of Cardiology, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- Vascular Biology Institute, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, United States of America
- * E-mail: (BG); (LS)
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25
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Kam JWK, Dumontier E, Baim C, Brignall AC, Mendes da Silva D, Cowan M, Kennedy TE, Cloutier JF. RGMB and neogenin control cell differentiation in the developing olfactory epithelium. Development 2017; 143:1534-46. [PMID: 27143755 DOI: 10.1242/dev.118638] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/29/2016] [Indexed: 12/25/2022]
Abstract
Cellular interactions are key for the differentiation of distinct cell types within developing epithelia, yet the molecular mechanisms engaged in these interactions remain poorly understood. In the developing olfactory epithelium (OE), neural stem/progenitor cells give rise to odorant-detecting olfactory receptor neurons (ORNs) and glial-like sustentacular (SUS) cells. Here, we show in mice that the transmembrane receptor neogenin (NEO1) and its membrane-bound ligand RGMB control the balance of neurons and glial cells produced in the OE. In this layered epithelium, neogenin is expressed in progenitor cells, while RGMB is restricted to adjacent newly born ORNs. Ablation of Rgmb via gene-targeting increases the number of dividing progenitor cells in the OE and leads to supernumerary SUS cells. Neogenin loss-of-function phenocopies these effects observed in Rgmb(-/-) mice, supporting the proposal that RGMB-neogenin signaling regulates progenitor cell numbers and SUS cell production. Interestingly, Neo1(-/-) mice also exhibit increased apoptosis of ORNs, implicating additional ligands in the neogenin-dependent survival of ORNs. Thus, our results indicate that RGMB-neogenin-mediated cell-cell interactions between newly born neurons and progenitor cells control the ratio of glia and neurons produced in the OE.
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Affiliation(s)
- Joseph Wai Keung Kam
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4
| | - Emilie Dumontier
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4
| | - Christopher Baim
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4
| | - Alexandra C Brignall
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4
| | - David Mendes da Silva
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Center for Neuroscience and Cell Biology and Department of Life Sciences, University of Coimbra, Rua Larga, Coimbra 3004-517, Portugal
| | - Mitra Cowan
- Centre de Recherches du Centre Hospitalier de l'Université de Montréal, 900 rue Saint-Denis, Montréal, Canada H2X 0A9
| | - Timothy E Kennedy
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Anatomy and Cell Biology, McGill University, 3640 University, Montréal, Québec, Canada H3A 0C7
| | - Jean-François Cloutier
- Montreal Neurological Institute, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Neurology and Neurosurgery, McGill University, 3801 University, Montréal, Québec, Canada H3A 2B4 Department of Anatomy and Cell Biology, McGill University, 3640 University, Montréal, Québec, Canada H3A 0C7
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26
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Coleman JH, Lin B, Schwob JE. Dissecting LSD1-Dependent Neuronal Maturation in the Olfactory Epithelium. J Comp Neurol 2017; 525:3391-3413. [PMID: 28597915 DOI: 10.1002/cne.24259] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/19/2017] [Accepted: 06/02/2017] [Indexed: 12/21/2022]
Abstract
Neurons in the olfactory epithelium (OE) each express a single dominant olfactory receptor (OR) allele from among roughly 1,000 different OR genes. While monogenic and monoallelic OR expression has been appreciated for over two decades, regulators of this process are still being described; most recently, epigenetic modifiers have been of high interest as silent OR genes are decorated with transcriptionally repressive trimethylated histone 3 lysine 9 (H3K9me3) whereas active OR genes are decorated with transcriptionally activating trimethylated histone 3 lysine 4 (H3K4me3). The lysine specific demethylase 1 (LSD1) demethylates at both of these lysine residues and has been shown to disrupt neuronal maturation and OR expression in the developing embryonic OE. Despite the growing literature on LSD1 expression in the OE, a complete characterization of the timing of LSD1 expression relative to neuronal maturation and of the function of LSD1 in the adult OE have yet to be reported. To fill this gap, the present study determined that LSD1 (1) is expressed in early dividing cells before OR expression and neuronal maturation and decreases at the time of OR stabilization; (2) colocalizes with the repressor CoREST (also known as RCOR1) and histone deacetylase 2 in these early dividing cells; and (3) is required for neuronal maturation during a distinct time window between activating reserve stem cells (horizontal basal cells) and Neurogenin1 (+) immediate neuronal precursors. Thus, this study clarifies the role of LSD1 in olfactory neuronal maturation.
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Affiliation(s)
- Julie H Coleman
- Department of Developmental, Molecular & Chemical Biology, School of Medicine, Tufts University, Boston, Massachusetts.,Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
| | - Brian Lin
- Department of Developmental, Molecular & Chemical Biology, School of Medicine, Tufts University, Boston, Massachusetts.,Program in Cell, Molecular & Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
| | - James E Schwob
- Department of Developmental, Molecular & Chemical Biology, School of Medicine, Tufts University, Boston, Massachusetts
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27
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Notch1 maintains dormancy of olfactory horizontal basal cells, a reserve neural stem cell. Proc Natl Acad Sci U S A 2017. [PMID: 28637720 DOI: 10.1073/pnas.1701333114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The remarkable capacity of the adult olfactory epithelium (OE) to regenerate fully both neurosensory and nonneuronal cell types after severe epithelial injury depends on life-long persistence of two stem cell populations: the horizontal basal cells (HBCs), which are quiescent and held in reserve, and mitotically active globose basal cells. It has recently been demonstrated that down-regulation of the ΔN form of the transcription factor p63 is both necessary and sufficient to release HBCs from dormancy. However, the mechanisms by which p63 is down-regulated after acute OE injury remain unknown. To identify the cellular source of potential signaling mechanisms, we assessed HBC activation after neuron-only and sustentacular cell death. We found that ablation of sustentacular cells is sufficient for HBC activation to multipotency. By expression analysis, next-generation sequencing, and immunohistochemical examination, down-regulation of Notch pathway signaling is coincident with HBC activation. Therefore, using HBC-specific conditional knockout of Notch receptors and overexpression of N1ICD, we show that Notch signaling maintains p63 levels and HBC dormancy, in contrast to its suppression of p63 expression in other tissues. Additionally, Notch1, but not Notch2, is required to maintain HBC dormancy after selective neuronal degeneration. Taken together, our data indicate that the activation of HBCs observed after tissue injury or sustentacular cell ablation is caused by the reduction/elimination of Notch signaling on HBCs; elimination of Jagged1 expressed by sustentacular cells may be the ligand responsible.
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28
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Fletcher RB, Das D, Gadye L, Street KN, Baudhuin A, Wagner A, Cole MB, Flores Q, Choi YG, Yosef N, Purdom E, Dudoit S, Risso D, Ngai J. Deconstructing Olfactory Stem Cell Trajectories at Single-Cell Resolution. Cell Stem Cell 2017; 20:817-830.e8. [PMID: 28506465 PMCID: PMC5484588 DOI: 10.1016/j.stem.2017.04.003] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/02/2017] [Accepted: 04/10/2017] [Indexed: 01/08/2023]
Abstract
A detailed understanding of the paths that stem cells traverse to generate mature progeny is vital for elucidating the mechanisms governing cell fate decisions and tissue homeostasis. Adult stem cells maintain and regenerate multiple mature cell lineages in the olfactory epithelium. Here we integrate single-cell RNA sequencing and robust statistical analyses with in vivo lineage tracing to define a detailed map of the postnatal olfactory epithelium, revealing cell fate potentials and branchpoints in olfactory stem cell lineage trajectories. Olfactory stem cells produce support cells via direct fate conversion in the absence of cell division, and their multipotency at the population level reflects collective unipotent cell fate decisions by single stem cells. We further demonstrate that Wnt signaling regulates stem cell fate by promoting neuronal fate choices. This integrated approach reveals the mechanisms guiding olfactory lineage trajectories and provides a model for deconstructing similar hierarchies in other stem cell niches.
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Affiliation(s)
- Russell B Fletcher
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Diya Das
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Levi Gadye
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
| | - Kelly N Street
- Division of Biostatistics, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Ariane Baudhuin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Allon Wagner
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Michael B Cole
- Department of Physics, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Quetzal Flores
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Yoon Gi Choi
- QB3 Functional Genomics Laboratory, University of California, Berkeley, CA 94720, USA
| | - Nir Yosef
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Elizabeth Purdom
- Department of Statistics, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Sandrine Dudoit
- Division of Biostatistics, University of California, Berkeley, CA 94720, USA; Department of Statistics, University of California, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Davide Risso
- Division of Biostatistics, University of California, Berkeley, CA 94720, USA
| | - John Ngai
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA; QB3 Functional Genomics Laboratory, University of California, Berkeley, CA 94720, USA.
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29
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Schwob JE, Jang W, Holbrook EH, Lin B, Herrick DB, Peterson JN, Hewitt Coleman J. Stem and progenitor cells of the mammalian olfactory epithelium: Taking poietic license. J Comp Neurol 2016; 525:1034-1054. [PMID: 27560601 DOI: 10.1002/cne.24105] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 12/15/2022]
Abstract
The capacity of the olfactory epithelium (OE) for lifelong neurogenesis and regeneration depends on the persistence of neurocompetent stem cells, which self-renew as well as generating all of the cell types found within the nasal epithelium. This Review focuses on the types of stem and progenitor cells in the epithelium and their regulation. Both horizontal basal cells (HBCs) and some among the population of globose basal cells (GBCs) are stem cells, but the two types plays vastly different roles. The GBC population includes the basal cells that proliferate in the uninjured OE and is heterogeneous with respect to transcription factor expression. From upstream in the hierarchy to downstream, GBCs encompass 1) Sox2+ /Pax6+ stem-like cells that are totipotent and self-renew over the long term, 2) Ascl1+ transit-amplifying progenitors with a limited capacity for expansive proliferation, and 3) Neurog1+ /NeuroD1+ immediate precursor cells that make neurons directly. In contrast, the normally quiescent HBCs are activated to multipotency and proliferate when sustentacular cells are killed, but not when only OSNs die, indicating that HBCs are reserve stem cells that respond to severe epithelial injury. The master regulator of HBC activation is the ΔN isoform of the transcription factor p63; eliminating ΔNp63 unleashes HBC multipotency. Notch signaling, via Jagged1 ligand on Sus cells and Notch1 and Notch2 receptors on HBCs, is likely to play a major role in setting the level of p63 expression. Thus, ΔNp63 becomes a potential therapeutic target for reversing the neurogenic exhaustion characteristic of the aged OE. J. Comp. Neurol. 525:1034-1054, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- James E Schwob
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Woochan Jang
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Eric H Holbrook
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Brian Lin
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Daniel B Herrick
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Jesse N Peterson
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
| | - Julie Hewitt Coleman
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02132
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30
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Parrilla M, Chang I, Degl'Innocenti A, Omura M. Expression of homeobox genes in the mouse olfactory epithelium. J Comp Neurol 2016; 524:2713-39. [PMID: 27243442 DOI: 10.1002/cne.24051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/16/2015] [Accepted: 05/25/2016] [Indexed: 01/22/2023]
Abstract
Homeobox genes constitute a large family of genes widely studied because of their role in the establishment of the body pattern. However, they are also involved in many other events during development and adulthood. The main olfactory epithelium (MOE) is an excellent model to study neurogenesis in the adult nervous system. Analyses of homeobox genes during development show that some of these genes are involved in the formation and establishment of cell diversity in the MOE. Moreover, the mechanisms of expression of odorant receptors (ORs) constitute one of the biggest enigmas in the field. Analyses of OR promoters revealed the presence of homeodomain binding sites in their sequences. Here we characterize the expression patterns of a set of 49 homeobox genes in the MOE with in situ hybridization. We found that seven of them (Dlx3, Dlx5, Dlx6, Msx1, Meis1, Isl1, and Pitx1) are zonally expressed. The homeobox gene Emx1 is expressed in three guanylate cyclase(+) populations, two located in the MOE and the third one in an olfactory subsystem known as Grüneberg ganglion located at the entrance of the nasal cavity. The homeobox gene Tshz1 is expressed in a unique patchy pattern across the MOE. Our findings provide new insights to guide functional studies that aim to understand the complexity of transcription factor expression and gene regulation in the MOE. J. Comp. Neurol. 524:2713-2739, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Marta Parrilla
- Max Planck Institut für Biophysik, Frankfurt am Main, Germany
| | - Isabelle Chang
- Max Planck Institut für Biophysik, Frankfurt am Main, Germany
| | - Andrea Degl'Innocenti
- Max Planck Institut für Biophysik, Frankfurt am Main, Germany.,Unità di Biologia Cellulare e dello Sviluppo, Dipartimento di Biologia, Università di Pisa, Pisa, Italy
| | - Masayo Omura
- Max Planck Institut für Biophysik, Frankfurt am Main, Germany
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31
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Regeneration and rewiring of rodent olfactory sensory neurons. Exp Neurol 2016; 287:395-408. [PMID: 27264358 DOI: 10.1016/j.expneurol.2016.06.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 05/27/2016] [Accepted: 06/01/2016] [Indexed: 12/24/2022]
Abstract
The olfactory sensory neurons are the only neurons in the mammalian nervous system that not only regenerate naturally and in response to injury, but also project to specific targets in the brain. The stem cells in the olfactory epithelium commit to both neuronal and non-neuronal lineages depending on the environmental conditions. They provide a continuous supply of new neurons. A newly generated neuron must express a specific odorant receptor gene and project to a central target consist of axons expressing the same receptor type. Recent studies have provided insights into this highly regulated, complex process. However, the molecular mechanisms that determine the regenerative capacity of stem cells, and the ability of newly generated neurons in directing their axons toward specific targets, remain elusive. Here we review progresses and controversies in the field and offer testable models.
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32
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Sox2 and Pax6 Play Counteracting Roles in Regulating Neurogenesis within the Murine Olfactory Epithelium. PLoS One 2016; 11:e0155167. [PMID: 27171428 PMCID: PMC4865097 DOI: 10.1371/journal.pone.0155167] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/25/2016] [Indexed: 12/13/2022] Open
Abstract
In the adult olfactory epithelium, the transcription factors Pax6 and Sox2 are co-expressed in sustentacular cells, horizontal basal cells (HBCs), and less-differentiated globose basal cells (GBCs)–both multipotent and transit amplifying categories—but are absent from immediate neuronal precursor GBCs and olfactory sensory neurons (OSNs). We used retroviral-vector transduction to over-express Pax6 and Sox2 individually and together during post-lesion recovery to determine how they regulate neuronal differentiation. Both Pax6 and Sox2, separately and together, can suppress the production of OSNs, as fewer clones contain neurons than with empty vector (EV), although this effect is not absolute. In this regard, Pax6 has the strongest effect when acting alone. In clones where neurons form, Pax6 reduces neuron numbers by comparison with EV, while Sox2 expands their numbers. Co-transduction with Pax6 and Sox2 produces an intermediate result. The increased production of OSNs driven by Sox2 is due to the expansion of neuronal progenitors, since proliferation and the numbers of Ascl1, Neurog1, and NeuroD1-expressing GBCs are increased. Conversely, Pax6 seems to accelerate neuronal differentiation, since Ascl1 labeling is reduced, while Neurog1- and NeuroD1-labeled GBCs are enriched. As a complement to the over-expression experiments, elimination of Sox2 in spared cells of floxed Sox2 mice, by retroviral Cre or by K5-driven CreERT2, reduces the production of OSNs and non-neuronal cells during OE regeneration. These data suggest that Pax6 and Sox2 have counteracting roles in regulating neurogenesis, in which Pax6 accelerates neuronal production, while Sox2 retards it and expands the pool of neuronal progenitors.
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33
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Transcription factor p63 controls the reserve status but not the stemness of horizontal basal cells in the olfactory epithelium. Proc Natl Acad Sci U S A 2015; 112:E5068-77. [PMID: 26305958 DOI: 10.1073/pnas.1512272112] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Adult tissue stem cells can serve two broad functions: to participate actively in the maintenance and regeneration of a tissue or to wait in reserve and participate only when activated from a dormant state. The adult olfactory epithelium, a site for ongoing, life-long, robust neurogenesis, contains both of these functional stem cell types. Globose basal cells (GBCs) act as the active stem cell population and can give rise to all the differentiated cells found in the normal tissue. Horizontal basal cells (HBCs) act as reserve stem cells and remain dormant unless activated by tissue injury. Here we show that HBC activation following injury by the olfactotoxic gas methyl bromide is coincident with the down-regulation of protein 63 (p63) but anticipates HBC proliferation. Gain- and loss-of-function studies show that this down-regulation of p63 is necessary and sufficient for HBC activation. Moreover, activated HBCs give rise to GBCs that persist for months and continue to act as bona fide stem cells by participating in tissue maintenance and regeneration over the long term. Our analysis provides mechanistic insight into the dynamics between tissue stem cell subtypes and demonstrates that p63 regulates the reserve state but not the stem cell status of HBCs.
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34
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Translational potential of olfactory mucosa for the study of neuropsychiatric illness. Transl Psychiatry 2015; 5:e527. [PMID: 25781226 PMCID: PMC4354342 DOI: 10.1038/tp.2014.141] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 10/22/2014] [Accepted: 11/17/2014] [Indexed: 01/02/2023] Open
Abstract
The olfactory mucosa (OM) is a unique source of regenerative neural tissue that is readily obtainable from living human subjects and thus affords opportunities for the study of psychiatric illnesses. OM tissues can be used, either as ex vivo OM tissue or in vitro OM-derived neural cells, to explore parameters that have been difficult to assess in the brain of living individuals with psychiatric illness. As OM tissues are distinct from brain tissues, an understanding of the neurobiology of the OM is needed to relate findings in these tissues to those of the brain as well as to design and interpret ex vivo or in vitro OM studies. To that end, we discuss the molecular, cellular and functional characteristics of cell types within the olfactory mucosa, describe the organization of the OM and highlight its role in the olfactory neurocircuitry. In addition, we discuss various approaches to in vitro culture of OM-derived cells and their characterization, focusing on the extent to which they reflect the in vivo neurobiology of the OM. Finally, we review studies of ex vivo OM tissues and in vitro OM-derived cells from individuals with psychiatric, neurodegenerative and neurodevelopmental disorders. In particular, we discuss the concordance of this work with postmortem brain studies and highlight possible future approaches, which may offer distinct strengths in comparison to in vitro paradigms based on genomic reprogramming.
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35
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36
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Pfister S, Weber T, Härtig W, Schwerdel C, Elsaesser R, Knuesel I, Fritschy JM. Novel role of cystic fibrosis transmembrane conductance regulator in maintaining adult mouse olfactory neuronal homeostasis. J Comp Neurol 2014; 523:406-30. [PMID: 25271146 DOI: 10.1002/cne.23686] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 02/03/2023]
Abstract
The olfactory epithelium (OE) of mice deficient in cystic fibrosis transmembrane conductance regulator (CFTR) exhibits ion transport deficiencies reported in human CF airways, as well as progressive neuronal loss, suggesting defects in olfactory neuron homeostasis. Microvillar cells, a specialized OE cell-subtype, have been implicated in maintaining tissue homeostasis. These cells are endowed with a PLCβ2/IP3 R3/TRPC6 signal transduction pathway modulating release of neuropeptide Y (NPY), which stimulates OE stem cell activity. It is unknown, however, whether microvillar cells also mediate the deficits observed in CFTR-null mice. Here we show that Cftr mRNA in mouse OE is exclusively localized in microvillar cells and CFTR immunofluorescence is coassociated with the scaffolding protein NHERF-1 and PLCβ2 in microvilli. In CFTR-null mice, PLCβ2 was undetectable, NHERF-1 mislocalized, and IP3 R3 more intensely stained, along with increased levels of NPY, suggesting profound alteration of the PLCβ2/IP3 R3 signaling pathway. In addition, basal olfactory neuron homeostasis was altered, shown by increased progenitor cell proliferation, differentiation, and apoptosis and by reduced regenerative capacity following methimazole-induced neurodegeneration. The importance of CFTR in microvillar cells was further underscored by decreased thickness of the OE mucus layer and increased numbers of immune cells within this tissue in CFTR-KO mice. Finally, we observed enhanced immune responses to an acute viral-like infection, as well as hyper-responsiveness to chemical and physical stimuli applied intranasally. Taken together, these data strengthen the notion that microvillar cells in the OE play a key role in maintaining tissue homeostasis and identify several mechanisms underlying this regulation through the multiple functions of CFTR.
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Affiliation(s)
- Sandra Pfister
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
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37
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Jang W, Chen X, Flis D, Harris M, Schwob JE. Label-retaining, quiescent globose basal cells are found in the olfactory epithelium. J Comp Neurol 2014; 522:731-49. [PMID: 24122672 DOI: 10.1002/cne.23470] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/10/2013] [Accepted: 09/13/2013] [Indexed: 02/01/2023]
Abstract
The vertebrate olfactory epithelium (OE) is known for its ability to renew itself throughout life as well as to reconstitute after injury. Although this remarkable capacity demonstrates the persistence of stem cells and multipotent progenitor cells, their nature in the OE remains undefined and controversial, as both horizontal basal cells (HBCs) and globose basal cells (GBCs) have features in common with each other and with stem cells in other tissues. Here, we investigate whether some among the population of GBCs satisfy a key feature of stem cells, i.e., mitotic quiescence with retention of thymidine analogue label and activation by injury. Accordingly, we demonstrate that some GBCs express p27(Kip1) , a member of the Kip/Cip family of cyclin-dependent kinase inhibitors. In addition, some GBCs retain bromodeoxyuridine or ethynyldeoxyuridine for an extended period when the pulse is administered in neonates followed by a 1-month chase. Their identity as GBCs was confirmed by electron microscopy. All spared GBCs express Ki-67 in the methyl bromide (MeBr)-lesioned OE initially after lesion, indicating that the label-retaining (LR) GBCs are activated in response to injury. LR-GBCs reappear during the acute recovery period following MeBr exposure, as demonstrated with 2- or 4-week chase periods after labeling. Taken together, our data demonstrate the existence of LR-GBCs that are seemingly activated in response to epithelial injury and then re-established after the initial phase of recovery is completed. In this regard, some among the GBCs satisfy a common criterion for functioning like stem cells.
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Affiliation(s)
- Woochan Jang
- Department of Developmental, Molecular, and Chemical Biology, School of Medicine, Tufts University, Boston, Massachusetts, 02111
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Wnt-responsive Lgr5⁺ globose basal cells function as multipotent olfactory epithelium progenitor cells. J Neurosci 2014; 34:8268-76. [PMID: 24920630 DOI: 10.1523/jneurosci.0240-14.2014] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Persistent neurogenesis in the olfactory epithelium provides a unique model to study neural stem cell self-renewal and fate determination. In the olfactory neuroepithelium, globose basal cells (GBCs) are considered to be the direct progenitors of olfactory neurons. However, the study of neurogenesis from GBCs has been impeded by the paucity of GBC-specific markers. Here we report that Lgr5, a recently discovered adult stem cell marker, is exclusively expressed in GBCs in neonatal and adult mice. Lgr5(+) cells display characteristics of cycling stem cells, including Ki67 expression and EdU incorporation. Lineage tracing analysis demonstrates that Lgr5(+) GBCs regenerate multiple cell types under normal turnover condition or after olfactory lesion. Furthermore, upregulation or downregulation of Wnt signaling in vivo indicates a key role of Wnt signaling not only in maintaining Lgr5(+) cell proliferation and promoting neuroregeneration, but also in delaying sensory neuron maturation. Together, our observations provided new insights into the dynamics of neurogenesis in the olfactory epithelium.
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Cellular and molecular mechanisms regulating embryonic neurogenesis in the rodent olfactory epithelium. Int J Dev Neurosci 2014; 37:76-86. [PMID: 25003986 DOI: 10.1016/j.ijdevneu.2014.06.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 06/27/2014] [Accepted: 06/28/2014] [Indexed: 02/08/2023] Open
Abstract
Mechanisms that regulate cellular differentiation in developing embryos are maintained across multiple physiological systems, including the nervous system where neurons and glia are generated. The olfactory epithelium, which arises from the olfactory pit, is a stratified tissue in which the stepwise generation of neurons and support cells can easily be assessed and followed during embryogenesis and throughout adulthood. During olfactory epithelium morphogenesis, progenitor cells respond to factors that control their proliferation, survival, and differentiation in order to generate olfactory receptor neurons that detect odorants in the environment and glia-like sustentacular cells. The tight temporal regulation of expression of proneural genes in dividing progenitor cells, including Mash-1, Neurogenin-1, and NeuroD1, plays a central role in the production of olfactory receptor neurons. Multiple factors that either positively or negatively affect the generation of olfactory receptor neurons have been identified and shown to impinge on the transcriptional regulatory network in dividing progenitor cells. Several growth factors, such as FGF-8, act to promote neurogenesis by ensuring survival of progenitor cells that will give rise to olfactory receptor neurons. In contrast, other molecules, including members of the large TGF-β family of proteins, have negative impacts on neurogenesis by restricting progenitor cell proliferation and stalling their differentiation. Since recent reviews have focused on neurogenesis in the regenerating adult olfactory epithelium, this review describes neurogenesis at embryonic stages of olfactory epithelium development and summarizes our current understanding of how both cell intrinsic and extrinsic factors control this process.
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Brann JH, Firestein SJ. A lifetime of neurogenesis in the olfactory system. Front Neurosci 2014; 8:182. [PMID: 25018692 PMCID: PMC4071289 DOI: 10.3389/fnins.2014.00182] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/09/2014] [Indexed: 12/11/2022] Open
Abstract
Neurogenesis continues well beyond embryonic and early postnatal ages in three areas of the nervous system. The subgranular zone supplies new neurons to the dentate gyrus of the hippocampus. The subventricular zone supplies new interneurons to the olfactory bulb, and the olfactory neuroepithelia generate new excitatory sensory neurons that send their axons to the olfactory bulb. The latter two areas are of particular interest as they contribute new neurons to both ends of a first-level circuit governing olfactory perception. The vomeronasal organ and the main olfactory epithelium comprise the primary peripheral olfactory epithelia. These anatomically distinct areas share common features, as each exhibits extensive neurogenesis well beyond the juvenile phase of development. Here we will discuss the effect of age on the structural and functional significance of neurogenesis in the vomeronasal and olfactory epithelia, from juvenile to advanced adult ages, in several common model systems. We will next discuss how age affects the regenerative capacity of these neural stem cells in response to injury. Finally, we will consider the integration of newborn neurons into an existing circuit as it is modified by the age of the animal.
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Affiliation(s)
- Jessica H Brann
- Department of Biology, Loyola University Chicago Chicago, IL, USA
| | - Stuart J Firestein
- Department of Biological Sciences, Columbia University New York, NY, USA ; Department of Neuroscience, Columbia University New York, NY, USA
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Wnt-responsive Lgr5⁺ globose basal cells function as multipotent olfactory epithelium progenitor cells. J Neurosci 2014. [PMID: 24920630 DOI: 10.1523/jneurosci.0240‐14.2014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Persistent neurogenesis in the olfactory epithelium provides a unique model to study neural stem cell self-renewal and fate determination. In the olfactory neuroepithelium, globose basal cells (GBCs) are considered to be the direct progenitors of olfactory neurons. However, the study of neurogenesis from GBCs has been impeded by the paucity of GBC-specific markers. Here we report that Lgr5, a recently discovered adult stem cell marker, is exclusively expressed in GBCs in neonatal and adult mice. Lgr5(+) cells display characteristics of cycling stem cells, including Ki67 expression and EdU incorporation. Lineage tracing analysis demonstrates that Lgr5(+) GBCs regenerate multiple cell types under normal turnover condition or after olfactory lesion. Furthermore, upregulation or downregulation of Wnt signaling in vivo indicates a key role of Wnt signaling not only in maintaining Lgr5(+) cell proliferation and promoting neuroregeneration, but also in delaying sensory neuron maturation. Together, our observations provided new insights into the dynamics of neurogenesis in the olfactory epithelium.
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Wittmann W, Iulianella A, Gunhaga L. Cux2 acts as a critical regulator for neurogenesis in the olfactory epithelium of vertebrates. Dev Biol 2014; 388:35-47. [PMID: 24512687 DOI: 10.1016/j.ydbio.2014.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 01/30/2014] [Accepted: 01/31/2014] [Indexed: 01/17/2023]
Abstract
Signaling pathways and transcription factors are crucial regulators of vertebrate neurogenesis, exerting their function in a spatial and temporal manner. Despite recent advances in our understanding of the molecular regulation of embryonic neurogenesis, little is known regarding how different signaling pathways interact to tightly regulate this process during the development of neuroepithelia. To address this, we have investigated the events lying upstream and downstream of a key neurogenic factor, the Cut-like homeodomain transcription factor-2 (Cux2), during embryonic neurogenesis in chick and mouse. By using the olfactory epithelium as a model for neurogenesis we have analyzed mouse embryos deficient in Cux2, as well as chick embryos exposed to Cux2 silencing (si) RNA or a Cux2 over-expression construct. We provide evidence that enhanced BMP activity increases Cux2 expression and suppresses olfactory neurogenesis in the chick olfactory epithelium. In addition, our results show that up-regulation of Cux2, either BMP-induced or ectopically over-expressed, reduce Delta1 expression and suppress proliferation. Interestingly, the loss of Cux2 activity, using mutant mice or siRNA in chick, also diminishes neurogenesis, Notch activity and cell proliferation in the olfactory epithelium. Our results suggest that controlled low levels of Cux2 activity are necessary for proper Notch signaling, maintenance of the proliferative pool and ongoing neurogenesis in the olfactory epithelium. Thus, we demonstrate a novel conserved mechanism in vertebrates in which levels of Cux2 activity play an important role for ongoing neurogenesis in the olfactory epithelium.
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Affiliation(s)
- Walter Wittmann
- Umeå Centre for Molecular Medicine, Umeå University, Building 6M 4th floor, 901 87 Umeå, Sweden.
| | - Angelo Iulianella
- Department of Medical Neuroscience, Dalhousie University, Halifax, Canada.
| | - Lena Gunhaga
- Umeå Centre for Molecular Medicine, Umeå University, Building 6M 4th floor, 901 87 Umeå, Sweden.
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Wittmann W, Schimmang T, Gunhaga L. Progressive effects of N-myc deficiency on proliferation, neurogenesis, and morphogenesis in the olfactory epithelium. Dev Neurobiol 2014; 74:643-56. [PMID: 24376126 PMCID: PMC4237195 DOI: 10.1002/dneu.22162] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/27/2013] [Accepted: 12/18/2013] [Indexed: 12/03/2022]
Abstract
N-myc belongs to the myc proto-oncogene family, which is
involved in numerous cellular processes such as proliferation, growth, apoptosis, and
differentiation. Conditional deletion of N-myc in the mouse nervous system
disrupted brain development, indicating that N-myc plays an essential role during
neural development. How the development of the olfactory epithelium and neurogenesis within are
affected by the loss of N-myc has, however, not been determined. To address these
issues, we examined an N-mycFoxg1Cre conditional mouse line, in which
N-myc is depleted in the olfactory epithelium. First changes in
N-myc mutants were detected at E11.5, with reduced proliferation and neurogenesis
in a slightly smaller olfactory epithelium. The phenotype was more pronounced at E13.5, with a
complete lack of Hes5-positive progenitor cells, decreased proliferation, and
neurogenesis. In addition, stereological analyses revealed reduced cell size of post-mitotic neurons
in the olfactory epithelium, which contributed to a smaller olfactory pit. Furthermore, we observed
diminished proliferation and neurogenesis also in the vomeronasal organ, which likewise was reduced
in size. In addition, the generation of gonadotropin-releasing hormone neurons was severely reduced
in N-myc mutants. Thus, diminished neurogenesis and proliferation in combination
with smaller neurons might explain the morphological defects in the N-myc depleted
olfactory structures. Moreover, our results suggest an important role for N-myc in
regulating ongoing neurogenesis, in part by maintaining the Hes5-positive
progenitor pool. In summary, our results provide evidence that N-myc deficiency in
the olfactory epithelium progressively diminishes proliferation and neurogenesis with negative
consequences at structural and cellular levels. © 2013 The Authors. Developmental
Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 74: 643–656, 2014
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Affiliation(s)
- Walter Wittmann
- Umeå Centre for Molecular Medicine, Umeå University, 901 87, Umeå, Sweden
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Kotagiri P, Chance SA, Szele FG, Esiri MM. Subventricular zone cytoarchitecture changes in autism. Dev Neurobiol 2013; 74:25-41. [PMID: 24002902 DOI: 10.1002/dneu.22127] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/29/2013] [Accepted: 08/26/2013] [Indexed: 12/12/2022]
Abstract
Autism is thought to be a neurodevelopmental disorder with symptoms developing during neonatal neurogenesis in the subventricular zone (SVZ). Autism associated genes alter SVZ proliferation and cytoarchitecture, yet the response of the human SVZ in autism is unknown. Epilepsy drives neurogenesis in rodents, but it is unclear how epilepsy interacts with autism in SVZ responses. The striatal and septal SVZ derive from separate lineages in rodents and generate different interneuron types. Yet it is unclear if autism unevenly regulates the striatal and septal SVZ. The human SVZ was immunohistochemically examined post-mortem from individuals with autism (n = 11) and controls (n = 11). Autism showed a lower cell density in the septal, but not striatal, SVZ hypocellular gap only in the absence of epilepsy. There was a decline in septal hypocellular gap cells with age in autism, but no correlation with age in controls. In contrast, PCNA+ cell numbers increased only in autism with epilepsy both in the hypocellular gap and in the ependymal layer on the septal but not striatal side. Ependymal cells also became GFAP immunoreactive in autism irrespective of epilepsy co-morbidity; however, this only occurred on the striatal side. In examining these questions we also discovered a subset of ependymal, astrocyte ribbon and RMS cells which express PCNA and Ki67, PLP, and α-tubulin. These results are the first example of a neuropsychiatric disease differentially affecting the septal and striatal SVZ. Altered cell density in the hypocellular gap and proliferation marker expression suggest individuals with autism may follow a different growth-trajectory.
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Affiliation(s)
- Prasanti Kotagiri
- Department of Neuropathology (Nuffield Department of Clinical Neuroscience), Oxford University Hospitals, University of Oxford, United Kingdom; Department of Medicine (Neuroscience), Monash University, Australia; Royal Melbourne Hospital, Australia
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Fu Y, Tvrdik P, Makki N, Machold R, Paxinos G, Watson C. The interfascicular trigeminal nucleus: a precerebellar nucleus in the mouse defined by retrograde neuronal tracing and genetic fate mapping. J Comp Neurol 2013; 521:697-708. [PMID: 22829396 DOI: 10.1002/cne.23200] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 07/18/2012] [Accepted: 07/19/2012] [Indexed: 11/06/2022]
Abstract
We have found a previously unreported precerebellar nucleus located among the emerging fibers of the motor root of the trigeminal nerve in the mouse, which we have called the interfascicular trigeminal nucleus (IF5). This nucleus had previously been named the tensor tympani part of the motor trigeminal nucleus (5TT) in rodent brain atlases, because it was thought to be a subset of small motor neurons of the motor trigeminal nucleus innervating the tensor tympani muscle. However, following injection of retrograde tracer in the cerebellum, the labeled neurons in IF5 were found to be choline acetyltransferase (ChAT) negative, indicating that they are not motor neurons. The cells of IF5 are strongly labeled in mice from Wnt1Cre and Atoh1 CreER lineage fate mapping, in common with the major precerebellar nuclei that arise from the rhombic lip and that issue mossy fibers. Analysis of sections from mouse Hoxa3, Hoxb1, and Egr2 Cre labeled lineages shows that the neurons of IF5 arise from rhombomeres caudal to rhombomere 4, most likely from rhombomeres 6-8. We conclude that IF5 is a significant precerebellar nucleus in the mouse that shares developmental gene expression characteristics with mossy fiber precerebellar nuclei that arise from the caudal rhombic lip.
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Affiliation(s)
- Yuhong Fu
- Neuroscience Research Australia, Randwick, New South Wales 2031, Australia
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Cell lineage analysis reveals three different progenitor pools for neurosensory elements in the otic vesicle. J Neurosci 2013; 32:16424-34. [PMID: 23152625 DOI: 10.1523/jneurosci.3686-12.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In the inner ear, sensory versus neuronal specification is achieved through few well-defined bHLH transcription factors. However, the molecular mechanisms regulating the generation of the appropriate cell type in the correct place and at the correct time are not completely understood yet. Various studies have shown that hair cell- and neuron-specifying genes partially overlap in the otic territory, suggesting that mutual interactions among these bHLH factors could direct the generation of the two cell types from a common neurosensory progenitor. Although there is little evidence for a clonal relationship between macular hair cells and sensory neurons, the existence of a single progenitor able to give both sensory and neuronal cell types remains an open question. Here, we identified a population of common neurosensory progenitors in the zebrafish inner ear and studied the proneural requirement for cell fate decision within this population. Expression analysis reveals that proneural genes for hair cells and neurons overlap within the posteromedial otic epithelium. Combined results from single-cell lineage and functional studies on neurog1 and neuroD1 further demonstrate the following: (1) in the anterior region of the ear, neuronal and sensory lineages have already segregated at the onset of proneural gene expression and are committed to a given fate very early; (2) in contrast, the posteromedial part of the ear harbors a population of common progenitors giving both neurons and hair cells until late stages; and finally (3) neuroD1 is required within this pool of bipotent progenitors to generate the hair cell fate.
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Zfp423/OAZ mutation reveals the importance of Olf/EBF transcription activity in olfactory neuronal maturation. J Neurosci 2013; 32:13679-88a. [PMID: 23035080 DOI: 10.1523/jneurosci.6190-11.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Zfp423/OAZ, a multi-zinc finger protein, is proposed to participate in neuronal differentiation through interactions with the Olf/EBF (O/E) family of transcription factors and mediate extrinsic BMP signaling pathways. These activities are associated with distinct domains of the Olf/EBF-associated zinc finger (OAZ) protein. Sustained OAZ expression arrests olfactory sensory neurons (OSNs) at an immature state and alters olfactory receptor expression, but the mechanism remains elusive. We show here that constitutive expression of a C-terminal mutant OAZ (OAZΔC) in mice that selectively disrupts OAZ-O/E interaction while retaining other activities, exhibits apparently normal OSN differentiation. Additionally, interfering with potential BMP signaling pathways by inducible Follistatin expression in adult mice does not alter the neuronal lineage or differentiation status. Our results indicate that O/E-mediated processes are essential for the differentiation of OSNs and the establishment of a mature phenotype. BMP signaling pathways, if they are active in normal adult olfactory epithelium, may play a minor role in this tissue.
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Suárez R, García-González D, de Castro F. Mutual influences between the main olfactory and vomeronasal systems in development and evolution. Front Neuroanat 2012; 6:50. [PMID: 23269914 PMCID: PMC3529325 DOI: 10.3389/fnana.2012.00050] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 11/26/2012] [Indexed: 12/14/2022] Open
Abstract
The sense of smell plays a crucial role in the sensory world of animals. Two chemosensory systems have been traditionally thought to play-independent roles in mammalian olfaction. According to this, the main olfactory system (MOS) specializes in the detection of environmental odorants, while the vomeronasal system (VNS) senses pheromones and semiochemicals produced by individuals of the same or different species. Although both systems differ in their anatomy and function, recent evidence suggests they act synergistically in the perception of scents. These interactions include similar responses to some ligands, overlap of telencephalic connections and mutual influences in the regulation of olfactory-guided behavior. In the present work, we propose the idea that the relationships between systems observed at the organismic level result from a constant interaction during development and reflects a common history of ecological adaptations in evolution. We review the literature to illustrate examples of developmental and evolutionary processes that evidence these interactions and propose that future research integrating both systems may shed new light on the mechanisms of olfaction.
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Affiliation(s)
- Rodrigo Suárez
- Queensland Brain Institute, The University of Queensland, St Lucia Brisbane, QLD, Australia ; Departamento de Biología, Facultad de Ciencias, Universidad de Chile Santiago, Chile
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Krolewski RC, Packard A, Jang W, Wildner H, Schwob JE. Ascl1 (Mash1) knockout perturbs differentiation of nonneuronal cells in olfactory epithelium. PLoS One 2012; 7:e51737. [PMID: 23284756 PMCID: PMC3524087 DOI: 10.1371/journal.pone.0051737] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/09/2012] [Indexed: 12/19/2022] Open
Abstract
The embryonic olfactory epithelium (OE) generates only a very few olfactory sensory neurons when the basic helix-loop-helix transcription factor, ASCL1 (previously known as MASH1) is eliminated by gene mutation. We have closely examined the structure and composition of the OE of knockout mice and found that the absence of neurons dramatically affects the differentiation of multiple other epithelial cell types as well. The most prominent effect is observed within the two known populations of stem and progenitor cells of the epithelium. The emergence of horizontal basal cells, a multipotent progenitor population in the adult epithelium, is anomalous in the Ascl1 knockout mice. The differentiation of globose basal cells, another multipotent progenitor population in the adult OE, is also aberrant. All of the persisting globose basal cells are marked by SOX2 expression, suggesting a prominent role for SOX2 in progenitors upstream of Ascl1. However, NOTCH1-expressing basal cells are absent from the knockout; since NOTCH1 signaling normally acts to suppress Ascl1 via HES1 and drives sustentacular (Sus) cell differentiation during adult epithelial regeneration, its absence suggests reciprocity between neurogenesis and the differentiation of Sus cells. Indeed, the Sus cells of the mutant mice express a markedly lower level of HES1, strengthening that notion of reciprocity. Duct/gland development appears normal. Finally, the expression of cKIT by basal cells is also undetectable, except in those small patches where neurogenesis escapes the effects of Ascl1 knockout and neurons are born. Thus, persistent neurogenic failure distorts the differentiation of multiple other cell types in the olfactory epithelium.
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Affiliation(s)
- Richard C. Krolewski
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Cellular, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Adam Packard
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Cellular, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Woochan Jang
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - James E. Schwob
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Berghard A, Hägglund AC, Bohm S, Carlsson L. Lhx2-dependent specification of olfactory sensory neurons is required for successful integration of olfactory, vomeronasal, and GnRH neurons. FASEB J 2012; 26:3464-72. [PMID: 22581782 DOI: 10.1096/fj.12-206193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Inactivation of the LIM-homeodomain 2 gene (Lhx2) results in a severe defect in specification of olfactory sensory neurons (OSNs). However, the ramifications of lack of Lhx2-dependent OSN specification for formation of the primary olfactory pathway have not been addressed, since mutant mice die in utero. We have analyzed prenatal and postnatal consequences of conditionally inactivating Lhx2 selectively in OSNs. A cell-autonomous effect is that OSN axons cannot innervate their target, the olfactory bulb. Moreover, the lack of Lhx2 in OSNs causes unpredicted, non-cell-autonomous phenotypes. First, the olfactory bulb shows pronounced hypoplasia in adults, and the data suggest that innervation by correctly specified OSNs is necessary for adult bulb size and organization. Second, absence of an olfactory nerve in the conditional mutant reveals that the vomeronasal nerve is dependent on olfactory nerve formation. Third, the lack of a proper vomeronasal nerve prevents migration of gonadotropin-releasing hormone (GnRH) cells the whole distance to their final positions in the hypothalamus during embryo development. As adults, the conditional mutants do not pass puberty, and these findings support the view of an exclusive nasal origin of GnRH neurons in the mouse. Thus, Lhx2 in OSNs is required for functional development of three separate systems.
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Affiliation(s)
- Anna Berghard
- Department of Molecular Biology, Byggn 6L, Umea University, SE90187 Umeå, Sweden.
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