1
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Yohe LR, Krell NT. An updated synthesis of and outstanding questions in the olfactory and vomeronasal systems in bats: Genetics asks questions only anatomy can answer. Anat Rec (Hoboken) 2023; 306:2765-2780. [PMID: 37523493 DOI: 10.1002/ar.25290] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 06/23/2023] [Accepted: 07/05/2023] [Indexed: 08/02/2023]
Abstract
The extensive diversity observed in bat nasal chemosensory systems has been well-documented at the histological level. Understanding how this diversity evolved and developing hypotheses as to why particular patterns exist require a phylogenetic perspective, which was first outlined in the work of anatomist Kunwar Bhatnagar. With the onset of genetics and genomics, it might be assumed that the puzzling patterns observed in the morphological data have been clarified. However, there is still a widespread mismatch of genetic and morphological correlations among bat chemosensory systems. Novel genomic evidence has set up new avenues to explore that demand more evidence from anatomical structures. Here, we outline the progress that has been made in both morphological and molecular studies on the olfactory and vomeronasal systems in bats since the work of Bhatnagar. Genomic data of olfactory and vomeronasal receptors demonstrate the strong need for further morphological sampling, with a particular focus on receiving brain regions, glands, and ducts.
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Affiliation(s)
- Laurel R Yohe
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
- North Carolina Research Campus, Kannapolis, North Carolina, USA
| | - Nicholas T Krell
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
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2
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Gunder N, Dörig P, Witt M, Welge-Lüssen A, Menzel S, Hummel T. Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview. HNO 2023; 71:35-43. [PMID: 36734997 PMCID: PMC9897160 DOI: 10.1007/s00106-022-01249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2022] [Indexed: 02/04/2023]
Abstract
Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.
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Affiliation(s)
- N Gunder
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - P Dörig
- Universitäts-HNO Klinik Basel, Basel, Switzerland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Germany
| | | | - S Menzel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - T Hummel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
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3
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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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4
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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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5
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Yohe LR, Fabbri M, Lee D, Davies KTJ, Yohe TP, Sánchez MKR, Rengifo EM, Hall RP, Mutumi G, Hedrick BP, Sadier A, Simmons NB, Sears KE, Dumont E, Rossiter SJ, Bhullar BAS, Dávalos LM. Ecological constraints on highly evolvable olfactory receptor genes and morphology in neotropical bats. Evolution 2022; 76:2347-2360. [PMID: 35904467 DOI: 10.1111/evo.14591] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/06/2022] [Accepted: 05/13/2022] [Indexed: 01/22/2023]
Abstract
Although evolvability of genes and traits may promote specialization during species diversification, how ecology subsequently restricts such variation remains unclear. Chemosensation requires animals to decipher a complex chemical background to locate fitness-related resources, and thus the underlying genomic architecture and morphology must cope with constant exposure to a changing odorant landscape; detecting adaptation amidst extensive chemosensory diversity is an open challenge. In phyllostomid bats, an ecologically diverse clade that evolved plant visiting from a presumed insectivorous ancestor, the evolution of novel food detection mechanisms is suggested to be a key innovation, as plant-visiting species rely strongly on olfaction, supplementarily using echolocation. If this is true, exceptional variation in underlying olfactory genes and phenotypes may have preceded dietary diversification. We compared olfactory receptor (OR) genes sequenced from olfactory epithelium transcriptomes and olfactory epithelium surface area of bats with differing diets. Surprisingly, although OR evolution rates were quite variable and generally high, they are largely independent of diet. Olfactory epithelial surface area, however, is relatively larger in plant-visiting bats and there is an inverse relationship between OR evolution rates and surface area. Relatively larger surface areas suggest greater reliance on olfactory detection and stronger constraint on maintaining an already diverse OR repertoire. Instead of the typical case in which specialization and elaboration are coupled with rapid diversification of associated genes, here the relevant genes are already evolving so quickly that increased reliance on smell has led to stabilizing selection, presumably to maintain the ability to consistently discriminate among specific odorants-a potential ecological constraint on sensory evolution.
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Affiliation(s)
- Laurel R Yohe
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, 06511, USA.,Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794, USA.,Deaprtment of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, 28223, USA.,North Carolina Research Campus, Kannapolis, North Carolina, 28081, USA
| | - Matteo Fabbri
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, 06511, USA.,Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, Illinois, 60605, USA
| | - Daniela Lee
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, 06511, USA.,Harvard School of Medicine, Cambridge, Massachusetts, 02115, USA
| | - Kalina T J Davies
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| | | | - Miluska K R Sánchez
- Escuela Profesional de Ciencias Biológicas, Universidad Nacional de Piura, Piura, 20004, Peru
| | - Edgardo M Rengifo
- Programa de Pós-Graduação Interunidades em Ecologia Aplicada, Escola Superior de Agricultura 'Luiz de Queiroz', Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, 13416-970, Brazil.,Centro de Investigación Biodiversidad Sostenible (BioS), Lima, 15073, Peru
| | - Ronald P Hall
- School of Natural Sciences, University of California, Merced, Merced, California, 95344, USA
| | - Gregory Mutumi
- School of Natural Sciences, University of California, Merced, Merced, California, 95344, USA
| | - Brandon P Hedrick
- Department of Biomedical Sciences, Cornell University, Ithaca, New York, 14853, USA
| | - Alexa Sadier
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, 90095, USA
| | - Nancy B Simmons
- Department of Mammalogy, American Museum of Natural History, New York, New York, 10024, USA
| | - Karen E Sears
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, 90095, USA
| | - Elizabeth Dumont
- School of Natural Sciences, University of California, Merced, Merced, California, 95344, USA
| | - Stephen J Rossiter
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - Bhart-Anjan S Bhullar
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, 06511, USA.,Yale Peabody Museum of Natural History, Yale University, New Haven, Connecticut, 06511, USA
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794, USA.,Center for Inter-Disciplinary Environmental Research, Stony Brook University, Stony Brook, New York, 11794, USA
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6
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Kowatschew D, Bozorg Nia S, Hassan S, Ustinova J, Weth F, Korsching SI. Spatial organization of olfactory receptor gene choice in the complete V1R-related ORA family of zebrafish. Sci Rep 2022; 12:14816. [PMID: 36045218 PMCID: PMC9433392 DOI: 10.1038/s41598-022-17900-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/02/2022] [Indexed: 11/12/2022] Open
Abstract
The vertebrate sense of smell employs four main receptor families for detection of odors, among them the V1R/ORA family, which is unusually small and highly conserved in teleost fish. Zebrafish possess just seven ORA receptors, enabling a comprehensive analysis of the expression patterns of the entire family. The olfactory organ of zebrafish is representative for teleosts, cup-shaped, with lamella covered with sensory epithelium protruding into the cup from a median raphe. We have performed quantitative in situ hybridization on complete series of horizontal cryostat sections of adult zebrafish olfactory organ, and have analysed the location of ora-expressing cells in three dimensions, radial diameter, laminar height, and height-within-the-organ. We report broadly overlapping, but distinctly different distributions for all ora genes, even for ora3a and ora3b, the most recent gene duplication. Preferred positions in different dimensions are independent of each other. This spatial logic is very similar to previous reports for the much larger families of odorant receptor (or) and V2R-related olfC genes in zebrafish. Preferred positions for ora genes tend to be more central and more apical than those we observed for these other two families, consistent with expression in non-canonical sensory neuron types.
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Affiliation(s)
- Daniel Kowatschew
- Institute of Genetics, Mathematical-Natural Sciences Faculty of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - Shahrzad Bozorg Nia
- Institute of Genetics, Mathematical-Natural Sciences Faculty of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - Shahzaib Hassan
- Institute of Genetics, Mathematical-Natural Sciences Faculty of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - Jana Ustinova
- Zoological Institute, Department of Cell- and Neurobiology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - Franco Weth
- Zoological Institute, Department of Cell- and Neurobiology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany
| | - Sigrun I Korsching
- Institute of Genetics, Mathematical-Natural Sciences Faculty of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany.
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7
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Sin SYW, Cloutier A, Nevitt G, Edwards SV. Olfactory receptor subgenome and expression in a highly olfactory procellariiform seabird. Genetics 2021; 220:6458329. [PMID: 34888634 DOI: 10.1093/genetics/iyab210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Procellariiform seabirds rely on their sense of smell for foraging and homing. Both genomes and transcriptomes yield important clues about how olfactory receptor (OR) subgenomes are shaped by natural and sexual selection, yet no transcriptomes have been made of any olfactory epithelium of any bird species thus far. Here we assembled a high-quality genome and nasal epithelium transcriptome of the Leach's storm-petrel (Oceanodroma leucorhoa) to extensively characterize their OR repertoire. Using a depth-of-coverage-assisted counting method, we estimated over 160 intact OR genes (∼500 including OR fragments). This method reveals the highest number of intact OR genes and the lowest proportion of pseudogenes compared to other waterbirds studied, and suggests that rates of OR gene duplication vary between major clades of birds, with particularly high rates in passerines. OR expression patterns reveal two OR genes (OR6-6 and OR5-11) highly expressed in adults, and four OR genes (OR14-14, OR14-12, OR10-2, and OR14-9) differentially expressed between age classes of storm-petrels. All four genes differentially expressed between age classes were more highly expressed in chicks compared to adults, suggesting that ORs genes may exhibit ontogenetic specializations. Three highly differentially expressed OR genes also had high copy number ratios, suggesting that expression variation may be linked to copy number in the genome. We provide better estimates of OR gene number by using a copy number-assisted counting method, and document ontogenetic changes in OR gene expression that may be linked to olfactory specialization. These results provide valuable insight into the expression, development, and macroevolution of olfaction in seabirds.
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Affiliation(s)
- Simon Yung Wa Sin
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.,School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China
| | - Alison Cloutier
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Gabrielle Nevitt
- Department of Neurobiology, Physiology and Behavior and the Graduate Group in Ecology, University of California, Davis, CA 95616, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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8
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Son G, Steinbusch HWM, López-Iglesias C, Moon C, Jahanshahi A. Severe histomorphological alterations in post-mortem olfactory glomeruli in Alzheimer's disease. Brain Pathol 2021; 32:e13033. [PMID: 34704631 PMCID: PMC8877757 DOI: 10.1111/bpa.13033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia. Key AD symptoms include memory and cognitive decline; however, comorbid symptoms such as depression and sensory‐perceptual dysfunction are often reported. Among these, a deterioration of olfactory sensation is observed in approximately 90% of AD patients. However, the precise pathophysiological basis underlying olfactory deficits because of AD remains elusive. The olfactory glomeruli in the olfactory bulb (OB) receive sensory information in the olfactory processing pathway. Maintaining the structural and functional integrity of the olfactory glomerulus is critical to olfactory signalling. Herein, we conducted an in‐depth histopathological assessment to reveal detailed structural alterations in the olfactory glomeruli in AD patients. Fresh frozen post‐mortem OB specimens obtained from six AD patients and seven healthy age‐matched individuals were examined. We used combined immunohistochemistry and stereology to assess the gross morphology and histological alterations, such as those in the expression of Aβ protein, microglia, and neurotransmitters in the OB. Electron microscopy was employed to study the ultrastructural features in the glomeruli. Significant accumulation of Aβ, morphologic damage, altered neurotransmitter levels, and microgliosis in the olfactory glomeruli of AD patients suggests that glomerular damage could affect olfactory function. Moreover, greater neurodegeneration was observed in the ventral olfactory glomeruli of AD patients. The synaptic ultrastructure revealed distorted postsynaptic densities and a decline in presynaptic vesicles in AD specimens. These findings show that the primary olfactory pathway is affected by the pathogenesis of AD, and may provide clues to identifying the mechanism involved in olfactory dysfunction in AD.
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Affiliation(s)
- Gowoon Son
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Republic of Korea.,Department of Neurosurgery, Maastricht University Medical Center+, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Harry W M Steinbusch
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Republic of Korea.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Carmen López-Iglesias
- Microscopy CORE Lab, Maastricht Multimodal Molecular Imaging Institute, FHML, Maastricht University, Maastricht, The Netherlands
| | - Cheil Moon
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Republic of Korea.,Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Republic of Korea.,Korea Brain Research Institute, Daegu, Republic of Korea
| | - Ali Jahanshahi
- Department of Neurosurgery, Maastricht University Medical Center+, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
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Son G, Jahanshahi A, Yoo SJ, Boonstra JT, Hopkins DA, Steinbusch HWM, Moon C. Olfactory neuropathology in Alzheimer's disease: a sign of ongoing neurodegeneration. BMB Rep 2021. [PMID: 34162463 PMCID: PMC8249876 DOI: 10.5483/bmbrep.2021.54.6.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Gowoon Son
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Ali Jahanshahi
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Seung-Jun Yoo
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu 42988, Korea
| | - Jackson T. Boonstra
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - David A. Hopkins
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax B3H 4R2, Canada
| | - Harry W. M. Steinbusch
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Cheil Moon
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu 42988, Korea
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10
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Son G, Jahanshahi A, Yoo SJ, Boonstra JT, Hopkins DA, Steinbusch HWM, Moon C. Olfactory neuropathology in Alzheimer's disease: a sign of ongoing neurodegeneration. BMB Rep 2021; 54:295-304. [PMID: 34162463 PMCID: PMC8249876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/06/2021] [Accepted: 05/06/2021] [Indexed: 11/08/2023] Open
Abstract
Olfactory neuropathology is a cause of olfactory loss in Alzheimer's disease (AD). Olfactory dysfunction is also associated with memory and cognitive dysfunction and is an incidental finding of AD dementia. Here we review neuropathological research on the olfactory system in AD, considering both structural and functional evidence. Experimental and clinical findings identify olfactory dysfunction as an early indicator of AD. In keeping with this, amyloid-β production and neuroinflammation are related to underlying causes of impaired olfaction. Notably, physiological features of the spatial map in the olfactory system suggest the evidence of ongoing neurodegeneration. Our aim in this review is to examine olfactory pathology findings essential to identifying mechanisms of olfactory dysfunction in the development of AD in hopes of supporting investigations leading towards revealing potential diagnostic methods and causes of early pathogenesis in the olfactory system. [BMB Reports 2021; 54(6): 295-304].
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Affiliation(s)
- Gowoon Son
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Ali Jahanshahi
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Seung-Jun Yoo
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu 42988, Korea
| | - Jackson T. Boonstra
- Department of Neurosurgery, MUMC+, Maastricht 6202 AZ, Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - David A. Hopkins
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax B3H 4R2, Canada
| | - Harry W. M. Steinbusch
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- School for Mental Health and Neuroscience, Maastricht University, Maastricht 6200 MD, the Netherlands
| | - Cheil Moon
- Department of Brain & Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu 42988, Korea
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11
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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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12
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Bloom ML, Johnston LB, Datta SR. Renewal and Differentiation of GCD Necklace Olfactory Sensory Neurons. Chem Senses 2021; 45:333-346. [PMID: 32333759 DOI: 10.1093/chemse/bjaa027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Both canonical olfactory sensory neurons (OSNs) and sensory neurons belonging to the guanylate cyclase D (GCD) "necklace" subsystem are housed in the main olfactory epithelium, which is continuously bombarded by toxins, pathogens, and debris from the outside world. Canonical OSNs address this challenge, in part, by undergoing renewal through neurogenesis; however, it is not clear whether GCD OSNs also continuously regenerate and, if so, whether newborn GCD precursors follow a similar developmental trajectory to that taken by canonical OSNs. Here, we demonstrate that GCD OSNs are born throughout adulthood and can persist in the epithelium for several months. Phosphodiesterase 2A is upregulated early in the differentiation process, followed by the sequential downregulation of β-tubulin and the upregulation of CART protein. The GCD and MS4A receptors that confer sensory responses upon GCD neurons are initially expressed midway through this process but become most highly expressed once CART levels are maximal late in GCD OSN development. GCD OSN maturation is accompanied by a horizontal migration of neurons toward the central, curved portions of the cul-de-sac regions where necklace cells are concentrated. These findings demonstrate that-like their canonical counterparts-GCD OSNs undergo continuous renewal and define a GCD-specific developmental trajectory linking neurogenesis, maturation, and migration.
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13
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Dörig P, Gunder N, Witt M, Welge-Lüssen A, Hummel T. [Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview]. HNO 2021; 69:623-632. [PMID: 33988723 PMCID: PMC8120256 DOI: 10.1007/s00106-021-01060-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 11/08/2022]
Abstract
Passagere oder permanente Riechstörungen können verschiedene Ursachen haben. Ganz aktuell berichtet eine Vielzahl von Patienten im Rahmen von COVID-19-Infektionen über ein fehlendes oder vermindertes Riechvermögen. In der Vergangenheit wurden vielfältige Therapieoptionen untersucht, diese variieren vom Riechtraining über Akupunktur und medikamentöse Therapien bis hin zur transkraniellen Magnetstimulation oder, z. B. bei ausgeprägten qualitativen Riechstörungen, der chirurgischen Resektion der Riechschleimhaut. Die Entwicklung einer bioelektrischen Nase, z. B. in Verbindung mit direkter elektrischer Stimulation des Bulbus olfactorius, oder die Transplantation von Riechschleimhaut oder von Stammzellen stellen Behandlungsmöglichkeiten der Zukunft dar. Die Grundlagen für diese Entwicklungen sowie der Stand des Wissens werden in der vorliegenden Arbeit erläutert.
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Affiliation(s)
- P Dörig
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz.
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Deutschland
| | - A Welge-Lüssen
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz
| | - T Hummel
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
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14
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Kuboki A, Kikuta S, Otori N, Kojima H, Matsumoto I, Reisert J, Yamasoba T. Insulin-Dependent Maturation of Newly Generated Olfactory Sensory Neurons after Injury. eNeuro 2021; 8:ENEURO.0168-21.2021. [PMID: 33906971 PMCID: PMC8143024 DOI: 10.1523/eneuro.0168-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 12/24/2022] Open
Abstract
Loss of olfactory sensory neurons (OSNs) after injury to the olfactory epithelium (OE) triggers the generation of OSNs that are incorporated into olfactory circuits to restore olfactory sensory perception. This study addresses how insulin receptor-mediated signaling affects the functional recovery of OSNs after OE injury. Insulin levels were reduced in mice by ablating the pancreatic β cells via streptozotocin (STZ) injections. These STZ-induced diabetic and control mice were then intraperitoneally injected with the olfactotoxic drug methimazole to selectively ablate OSNs. The OE of diabetic and control mice regenerated similarly until day 14 after injury. Thereafter, the OE of diabetic mice contained fewer mature and more apoptotic OSNs than control mice. Functionally, diabetic mice showed reduced electro-olfactogram (EOG) responses and their olfactory bulbs (OBs) had fewer c-Fos-active cells following odor stimulation, as well as performed worse in an odor-guided task compared with control mice. Insulin administered intranasally during days 8-13 after injury was sufficient to rescue recovery of OSNs in diabetic mice compared with control levels, while insulin administration between days 1 and 6 did not. During this critical time window on days 8-13 after injury, insulin receptors are highly expressed and intranasal application of an insulin receptor antagonist inhibits regeneration. Furthermore, an insulin-enriched environment could facilitate regeneration even in non-diabetic mice. These results indicate that insulin facilitates the regeneration of OSNs after injury and suggest a critical stage during recovery (8-13 d after injury) during which the maturation of newly generated OSNs is highly dependent on and promoted by insulin.
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Affiliation(s)
- Akihito Kuboki
- Department of Otolaryngology, Jikei University School of Medicine, Tokyo 105-8461, Japan
- Monell Chemical Senses Center, Philadelphia, PA 19104
| | - Shu Kikuta
- Department of Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Nobuyoshi Otori
- Department of Otolaryngology, Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Hiromi Kojima
- Department of Otolaryngology, Jikei University School of Medicine, Tokyo 105-8461, Japan
| | | | | | - Tatsuya Yamasoba
- Department of Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
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15
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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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16
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Diving into the streams and waves of constitutive and regenerative olfactory neurogenesis: insights from zebrafish. Cell Tissue Res 2020; 383:227-253. [PMID: 33245413 DOI: 10.1007/s00441-020-03334-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023]
Abstract
The olfactory system is renowned for its functional and structural plasticity, with both peripheral and central structures displaying persistent neurogenesis throughout life and exhibiting remarkable capacity for regenerative neurogenesis after damage. In general, fish are known for their extensive neurogenic ability, and the zebrafish in particular presents an attractive model to study plasticity and adult neurogenesis in the olfactory system because of its conserved structure, relative simplicity, rapid cell turnover, and preponderance of neurogenic niches. In this review, we present an overview of the anatomy of zebrafish olfactory structures, with a focus on the neurogenic niches in the olfactory epithelium, olfactory bulb, and ventral telencephalon. Constitutive and regenerative neurogenesis in both the peripheral olfactory organ and central olfactory bulb of zebrafish is reviewed in detail, and a summary of current knowledge about the cellular origin and molecular signals involved in regulating these processes is presented. While some features of physiologic and injury-induced neurogenic responses are similar, there are differences that indicate that regeneration is not simply a reiteration of the constitutive proliferation process. We provide comparisons to mammalian neurogenesis that reveal similarities and differences between species. Finally, we present a number of open questions that remain to be answered.
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17
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Chen ZH, Luo XC, Yu CR, Huang L. Matrix metalloprotease-mediated cleavage of neural glial-related cell adhesion molecules activates quiescent olfactory stem cells via EGFR. Mol Cell Neurosci 2020; 108:103552. [PMID: 32918999 DOI: 10.1016/j.mcn.2020.103552] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/23/2020] [Accepted: 09/06/2020] [Indexed: 12/14/2022] Open
Abstract
Quiescent stem cells have been found in multiple adult organs, and activation of these stem cells is critical to the restoration of damaged tissues in response to injury or stress. Existing evidence suggests that extrinsic cues from the extracellular matrix or supporting cells of various stem cell niches may interact with intrinsic components to initiate stem cell differentiation, but the molecular and cellular mechanisms regulating their activation are not fully understood. In the present study, we find that olfactory horizontal basal cells (HBCs) are stimulated by neural glial-related cell adhesion molecules (NrCAMs). NrCAM activation requires matrix metalloproteases (MMPs) and epidermal growth factor receptors (EGFRs). Inhibiting MMP activity or EGFR activation not only blocks HBC proliferation in the cultured olfactory organoids, but also severely suppresses HBC proliferation in the olfactory epithelium following methimazole-induced injury, resulting in a delay of olfactory mucosa reconstitution and functional recovery of the injured mice. Both NrCAMs and EGFR are expressed by the HBCs and their expression increases upon injury. Our data indicate that MMP-mediated cleavage of NrCAMs serves as an autocrine or paracrine signal that activates EGFRs on HBCs to trigger HBC proliferation and differentiation to reconstruct the entire olfactory epithelium following injury.
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Affiliation(s)
- Zhen-Huang Chen
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiao-Cui Luo
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - C Ron Yu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Liquan Huang
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang 310027, China; Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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18
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Sustentacular Cell Enwrapment of Olfactory Receptor Neuronal Dendrites: An Update. Genes (Basel) 2020; 11:genes11050493. [PMID: 32365880 PMCID: PMC7291085 DOI: 10.3390/genes11050493] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
The pseudostratified olfactory epithelium (OE) may histologically appear relatively simple, but the cytological relations among its cell types, especially those between olfactory receptor neurons (ORNs) and olfactory sustentacular cells (OSCs), prove more complex and variable than previously believed. Adding to the complexity is the short lifespan, persistent neurogenesis, and continuous rewiring of the ORNs. Contrary to the common belief that ORN dendrites are mostly positioned between OSCs, recent findings indicate a sustentacular cell enwrapped configuration for a majority of mature ORN dendrites at the superficial layer of the OE. After vertically sprouting out from the borderlines between OSCs, most of the immature ORN dendrites undergo a process of sideways migration and terminal maturation to become completely invaginated into and enwrapped by OSCs. Trailing the course of the dendritic sideways migration is the mesodendrite (mesentery of the enwrapped dendrite) made of closely apposed, cell junction connected plasma membrane layers of neighboring folds of the host sustentacular cell. Only a minority of the mature ORN dendrites at the OE apical surface are found at the borderlines between OSCs (unwrapped). Below I give a brief update on the cytoarchitectonic relations between the ORNs and OSCs of the OE. Emphasis is placed on the enwrapment of ORN dendrites by OSCs, on the sideways migration of immature ORN dendrites after emerging from the OE surface, and on the terminal maturation of the ORNs. Functional implications of ORN dendrite enwrapment and a comparison with myelination or Remak’s bundling of axons or axodendrites in the central and peripheral nervous system are also discussed.
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19
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Naik AS, Lin JM, Taroc EZM, Katreddi RR, Frias JA, Lemus AA, Sammons MA, Forni PE. Smad4-dependent morphogenic signals control the maturation and axonal targeting of basal vomeronasal sensory neurons to the accessory olfactory bulb. Development 2020; 147:147/8/dev184036. [PMID: 32341026 PMCID: PMC7197725 DOI: 10.1242/dev.184036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 03/10/2020] [Indexed: 12/31/2022]
Abstract
The vomeronasal organ (VNO) contains two main types of vomeronasal sensory neurons (VSNs) that express distinct vomeronasal receptor (VR) genes and localize to specific regions of the neuroepithelium. Morphogenic signals are crucial in defining neuronal identity and network formation; however, if and what signals control maturation and homeostasis of VSNs is largely unexplored. Here, we found transforming growth factor β (TGFβ) and bone morphogenetic protein (BMP) signal transduction in postnatal mice, with BMP signaling being restricted to basal VSNs and at the marginal zones of the VNO: the site of neurogenesis. Using different Smad4 conditional knockout mouse models, we disrupted canonical TGFβ/BMP signaling in either maturing basal VSNs (bVSNs) or all mature VSNs. Smad4 loss of function in immature bVSNs compromises dendritic knob formation, pheromone induced activation, correct glomeruli formation in the accessory olfactory bulb (AOB) and survival. However, Smad4 loss of function in all mature VSNs only compromises correct glomeruli formation in the posterior AOB. Our results indicate that Smad4-mediated signaling drives the functional maturation and connectivity of basal VSNs. Summary: Genetic disruption of TGFβ/BMP signaling in maturing basal vomeronasal sensory neurons (VSNs) or in all mature VSNs indicates that Smad4 signaling drives maturation and connectivity of basal VSNs.
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Affiliation(s)
- Ankana S Naik
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Jennifer M Lin
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Ed Zandro M Taroc
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Raghu R Katreddi
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Jesus A Frias
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Alex A Lemus
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Morgan A Sammons
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
| | - Paolo E Forni
- Department of Biological Sciences; The RNA Institute; University at Albany, State University of New York, Albany, NY 12222, USA
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20
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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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21
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A Group of Olfactory Receptor Alleles that Encode Full Length Proteins are Down-Regulated as Olfactory Sensory Neurons Mature. Sci Rep 2020; 10:1781. [PMID: 32020011 PMCID: PMC7000733 DOI: 10.1038/s41598-020-58779-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 01/21/2020] [Indexed: 11/08/2022] Open
Abstract
The family of olfactory receptors (ORs) subserves the sense of smell and includes both functional alleles and pseudogenes, the latter identified by mutations resulting in frame shift or premature truncation. During neuronal differentiation, nonfunctional ORs are expressed initially but then are switched out, and/or the olfactory sensory neurons (OSNs) expressing them die. We carried out a transcriptomic analysis of FACS-isolated cells from ΔSox2-eGFP, Neurog1-eGFP BAC and ΔOMP-eGFP strains of uninjured and olfactory bulbectomized transgenic mice that correspond to distinct stages in the progression from globose basal cell stem cells to fully mature OSNs. We analyzed the expression pattern of 1094 unique receptors across this progression and found that the vast majority were characterized by a typical and expected pattern of expression; i.e., levels of OR mRNA peaking in mature OSNs. However, 43 ORs, including several known pseudogenes, were different, such that mRNA expression declined in the mature OSNs relative to earlier stages. Protein and promoter sequence analysis of the atypical group did not uncover any obvious differences between them and more typical ORs. Nonetheless, the pattern of expression suggests that atypical ORs may be non-functional despite the lack of any obvious abnormality in the sequence analyses.
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