1
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Branch MC, Weber M, Li MY, Flora P, Ezhkova E. Overview of chromatin regulatory processes during surface ectodermal development and homeostasis. Dev Biol 2024; 515:30-45. [PMID: 38971398 PMCID: PMC11317222 DOI: 10.1016/j.ydbio.2024.07.001] [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: 11/15/2023] [Revised: 05/02/2024] [Accepted: 07/02/2024] [Indexed: 07/08/2024]
Abstract
The ectoderm is the outermost of the three germ layers of the early embryo that arise during gastrulation. Once the germ layers are established, the complex interplay of cellular proliferation, differentiation, and migration results in organogenesis. The ectoderm is the progenitor of both the surface ectoderm and the neural ectoderm. Notably, the surface ectoderm develops into the epidermis and its associated appendages, nails, external exocrine glands, olfactory epithelium, and the anterior pituitary. Specification, development, and homeostasis of these organs demand a tightly orchestrated gene expression program that is often dictated by epigenetic regulation. In this review, we discuss the recent discoveries that have highlighted the importance of chromatin regulatory mechanisms mediated by transcription factors, histone and DNA modifications that aid in the development of surface ectodermal organs and maintain their homeostasis post-development.
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Affiliation(s)
- Meagan C Branch
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Madison Weber
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Meng-Yen Li
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Pooja Flora
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Elena Ezhkova
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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2
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Liao W, Wang Y, Wang L, Li J, Huang D, Cheng W, Luan P. The current status and challenges of olfactory dysfunction study in Alzheimer's Disease. Ageing Res Rev 2024; 100:102453. [PMID: 39127444 DOI: 10.1016/j.arr.2024.102453] [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: 06/26/2024] [Accepted: 08/07/2024] [Indexed: 08/12/2024]
Abstract
Olfactory functioning involves multiple cognitive processes and the coordinated actions of various neural systems. Any disruption at any stage of this process may result in olfactory dysfunction, which is consequently widely used to predict the onset and progression of diseases, such as Alzheimer's Disease (AD). Although the underlying mechanisms have not yet been fully unraveled, apparent changes were observed in olfactory brain areas form patients who suffer from AD by means of medical imaging and electroencephalography (EEG). Olfactory dysfunction holds significant promise in detecting AD during the preclinical stage preceding mild cognitive impairment (MCI). Owing to the strong specificity, olfactory tests are prevalently applied for screening in community cohorts. And combining olfactory tests with other biomarkers may further establish an optimal model for AD prediction in studies of specific olfactory dysfunctions and improve the sensitivity and specificity of early AD diagnosis.
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Affiliation(s)
- Wanchen Liao
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Yulin Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Lei Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Jun Li
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Dongqing Huang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Weibin Cheng
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
| | - Ping Luan
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
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3
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Al-Saigh NN, Harb AA, Abdalla S. Receptors Involved in COVID-19-Related Anosmia: An Update on the Pathophysiology and the Mechanistic Aspects. Int J Mol Sci 2024; 25:8527. [PMID: 39126095 PMCID: PMC11313362 DOI: 10.3390/ijms25158527] [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: 06/25/2024] [Revised: 07/31/2024] [Accepted: 08/01/2024] [Indexed: 08/12/2024] Open
Abstract
Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.
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Affiliation(s)
- Noor N. Al-Saigh
- Department of Basic Medical Sciences, Faculty of Medicine, Ibn Sina University for Medical Sciences, Amman 16197, Jordan;
| | - Amani A. Harb
- Department of Basic Sciences, Faculty of Arts and Sciences, Al-Ahliyya Amman University, Amman 19111, Jordan;
| | - Shtaywy Abdalla
- Department of Biological Sciences, School of Science, The University of Jordan, Amman 11942, Jordan
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4
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Heiman MG, Bülow HE. Dendrite morphogenesis in Caenorhabditis elegans. Genetics 2024; 227:iyae056. [PMID: 38785371 PMCID: PMC11151937 DOI: 10.1093/genetics/iyae056] [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: 12/18/2023] [Accepted: 04/02/2024] [Indexed: 05/25/2024] Open
Abstract
Since the days of Ramón y Cajal, the vast diversity of neuronal and particularly dendrite morphology has been used to catalog neurons into different classes. Dendrite morphology varies greatly and reflects the different functions performed by different types of neurons. Significant progress has been made in our understanding of how dendrites form and the molecular factors and forces that shape these often elaborately sculpted structures. Here, we review work in the nematode Caenorhabditis elegans that has shed light on the developmental mechanisms that mediate dendrite morphogenesis with a focus on studies investigating ciliated sensory neurons and the highly elaborated dendritic trees of somatosensory neurons. These studies, which combine time-lapse imaging, genetics, and biochemistry, reveal an intricate network of factors that function both intrinsically in dendrites and extrinsically from surrounding tissues. Therefore, dendrite morphogenesis is the result of multiple tissue interactions, which ultimately determine the shape of dendritic arbors.
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Affiliation(s)
- Maxwell G Heiman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Hannes E Bülow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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5
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Chang K, Zaikos T, Kilner-Pontone N, Ho CY. Mechanisms of COVID-19-associated olfactory dysfunction. Neuropathol Appl Neurobiol 2024; 50:e12960. [PMID: 38419211 PMCID: PMC10906737 DOI: 10.1111/nan.12960] [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: 06/15/2023] [Revised: 12/26/2023] [Accepted: 01/08/2024] [Indexed: 03/02/2024]
Abstract
Olfactory dysfunction is one of the most common symptoms of COVID-19. In the first 2 years of the pandemic, it was frequently reported, although its incidence has significantly decreased with the emergence of the Omicron variant, which has since become the dominant viral strain. Nevertheless, many patients continue to suffer from persistent dysosmia and dysgeusia, making COVID-19-associated olfactory dysfunction an ongoing health concern. The proposed pathogenic mechanisms of COVID-19-associated olfactory dysfunction are complex and likely multifactorial. While evidence suggests that infection of sustentacular cells and associated mucosal inflammation may be the culprit of acute, transient smell loss, alterations in other components of the olfactory system (e.g., olfactory receptor neuron dysfunction, olfactory bulb injury and alterations in the olfactory cortex) may lead to persistent, long-term olfactory dysfunction. This review aims to provide a comprehensive summary of the epidemiology, clinical manifestations and current understanding of the pathogenic mechanisms of COVID-19-associated olfactory dysfunction.
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Affiliation(s)
- Koping Chang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department and Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan
| | - Thomas Zaikos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Cheng-Ying Ho
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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6
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Butowt R, von Bartheld CS. Timing and cause of olfactory deciliation in COVID-19. Physiol Rev 2024; 104:589-590. [PMID: 38206010 DOI: 10.1152/physrev.00035.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 01/12/2024] Open
Affiliation(s)
- Rafal Butowt
- Medical Science Center, Faculty of Medicine, Bydgoszcz University of Science and Technology, Bydgoszcz, Poland
| | - Christopher S von Bartheld
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno, Nevada, United States
- Center of Biomedical Research Excellence in Cell Biology, School of Medicine, University of Nevada, Reno, Reno, Nevada, United States
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7
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Marin C, Alobid I, López-Chacón M, VanStrahlen CR, Mullol J. Type 2 and Non-type 2 Inflammation in the Upper Airways: Cellular and Molecular Alterations in Olfactory Neuroepithelium Cell Populations. Curr Allergy Asthma Rep 2024; 24:211-219. [PMID: 38492160 PMCID: PMC11008081 DOI: 10.1007/s11882-024-01137-x] [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] [Accepted: 02/15/2024] [Indexed: 03/18/2024]
Abstract
PURPOSE OF REVIEW Neurogenesis occurring in the olfactory epithelium is critical to continuously replace olfactory neurons to maintain olfactory function, but is impaired during chronic type 2 and non-type 2 inflammation of the upper airways. In this review, we describe the neurobiology of olfaction and the olfactory alterations in chronic rhinosinusitis with nasal polyps (type 2 inflammation) and post-viral acute rhinosinusitis (non-type 2 inflammation), highlighting the role of immune response attenuating olfactory neurogenesis as a possibly mechanism for the loss of smell in these diseases. RECENT FINDINGS Several studies have provided relevant insights into the role of basal stem cells as direct participants in the progression of chronic inflammation identifying a functional switch away from a neuro-regenerative phenotype to one contributing to immune defense, a process that induces a deficient replacement of olfactory neurons. The interaction between olfactory stem cells and immune system might critically underlie ongoing loss of smell in type 2 and non-type 2 inflammatory upper airway diseases. In this review, we describe the neurobiology of olfaction and the olfactory alterations in type 2 and non-type 2 inflammatory upper airway diseases, highlighting the role of immune response attenuating olfactory neurogenesis, as a possibly mechanism for the lack of loss of smell recovery.
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Affiliation(s)
- Concepció Marin
- INGENIO, IRCE, Fundació Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain.
- Centre for Biomedical Research in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.
| | - Isam Alobid
- INGENIO, IRCE, Fundació Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
- Centre for Biomedical Research in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain
- Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Barcelona, Catalonia, Spain
- Universitat de Barcelona, Barcelona, Spain
| | - Mauricio López-Chacón
- INGENIO, IRCE, Fundació Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
- Centre for Biomedical Research in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain
- Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Barcelona, Catalonia, Spain
| | - Camilo R VanStrahlen
- INGENIO, IRCE, Fundació Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
- Centre for Biomedical Research in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain
- Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Barcelona, Catalonia, Spain
| | - Joaquim Mullol
- INGENIO, IRCE, Fundació Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain.
- Centre for Biomedical Research in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.
- Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Barcelona, Catalonia, Spain.
- Universitat de Barcelona, Barcelona, Spain.
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8
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Simonini L, Frijia F, Ait Ali L, Foffa I, Vecoli C, De Gori C, De Cori S, Baroni M, Aquaro GD, Maremmani C, Lombardo F. A Comprehensive Review of COVID-19-Related Olfactory Deficiency: Unraveling Associations with Neurocognitive Disorders and Magnetic Resonance Imaging Findings. Diagnostics (Basel) 2024; 14:359. [PMID: 38396398 PMCID: PMC10888385 DOI: 10.3390/diagnostics14040359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/31/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Olfactory dysfunction (OD) is one of the most common symptoms in COVID-19 patients and can impact patients' lives significantly. The aim of this review was to investigate the multifaceted impact of COVID-19 on the olfactory system and to provide an overview of magnetic resonance (MRI) findings and neurocognitive disorders in patients with COVID-19-related OD. Extensive searches were conducted across PubMed, Scopus, and Google Scholar until 5 December 2023. The included articles were 12 observational studies and 1 case report that assess structural changes in olfactory structures, highlighted through MRI, and 10 studies correlating the loss of smell with neurocognitive disorders or mood disorders in COVID-19 patients. MRI findings consistently indicate volumetric abnormalities, altered signal intensity of olfactory bulbs (OBs), and anomalies in the olfactory cortex among COVID-19 patients with persistent OD. The correlation between OD and neurocognitive deficits reveals associations with cognitive impairment, memory deficits, and persistent depressive symptoms. Treatment approaches, including olfactory training and pharmacological interventions, are discussed, emphasizing the need for sustained therapeutic interventions. This review points out several limitations in the current literature while exploring the intricate effects of COVID-19 on OD and its connection to cognitive deficits and mood disorders. The lack of objective olfactory measurements in some studies and potential validity issues in self-reports emphasize the need for cautious interpretation. Our research highlights the critical need for extensive studies with larger samples, proper controls, and objective measurements to deepen our understanding of COVID-19's long-term effects on neurological and olfactory dysfunctions.
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Affiliation(s)
- Ludovica Simonini
- Institute of Clinical Physiology, National Research Council (CNR), 54100 Massa, Italy; (I.F.); (C.V.)
| | - Francesca Frijia
- Bioengineering Unit, Fondazione Toscana G. Monasterio, 56124 Pisa, Italy;
| | - Lamia Ait Ali
- Institute of Clinical Physiology, National Research Council (CNR), 54100 Massa, Italy; (I.F.); (C.V.)
- Pediatric Cardiology and GUCH Unit, Fondazione “G. Monasterio” CNR-Regione Toscana, 54100 Massa, Italy
| | - Ilenia Foffa
- Institute of Clinical Physiology, National Research Council (CNR), 54100 Massa, Italy; (I.F.); (C.V.)
| | - Cecilia Vecoli
- Institute of Clinical Physiology, National Research Council (CNR), 54100 Massa, Italy; (I.F.); (C.V.)
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy; (C.D.G.); (S.D.C.); (F.L.)
| | - Sara De Cori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy; (C.D.G.); (S.D.C.); (F.L.)
| | - Monica Baroni
- Fondazione “G. Monasterio” CNR-Regione Toscana, 54100 Massa, Italy;
| | - Giovanni Donato Aquaro
- Academic Radiology Unit, Department of Surgical, Medical and Molecular Pathology and Critical Area, University of Pisa, 56124 Pisa, Italy;
| | - Carlo Maremmani
- Unit of Neurology, Ospedale Apuane, Azienda USL Toscana Nord Ovest, 54100 Massa, Italy;
| | - Francesco Lombardo
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy; (C.D.G.); (S.D.C.); (F.L.)
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9
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Kumpitsch C, Fischmeister FPS, Lackner S, Holasek S, Madl T, Habisch H, Wolf A, Schöpf V, Moissl-Eichinger C. Reduced olfactory performance is associated with changed microbial diversity, oralization, and accumulation of dead biomaterial in the nasal olfactory area. Microbiol Spectr 2024; 12:e0154923. [PMID: 38193689 PMCID: PMC10846256 DOI: 10.1128/spectrum.01549-23] [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: 04/17/2023] [Accepted: 12/09/2023] [Indexed: 01/10/2024] Open
Abstract
The partial or complete loss of the sense of smell, which affects about 20% of the population, impairs the quality of life in many ways. Dysosmia and anosmia are mainly caused by aging, trauma, infections, or even neurodegenerative disease. Recently, the olfactory area-a site containing the olfactory receptor cells responsible for odor perception-was shown to harbor a complex microbiome that reflects the state of olfactory function. This initially observed correlation between microbiome composition and olfactory performance needed to be confirmed using a larger study cohort and additional analyses. A total of 120 participants (middle-aged, no neurodegenerative disease) were enrolled in the study to further analyze the microbial role in human olfactory function. Olfactory performance was assessed using the Sniffin' Stick battery, and participants were grouped accordingly (normosmia: n = 93, dysosmia: n = 27). The olfactory microbiome was analyzed by 16S rRNA gene amplicon sequencing and supplemented by metatranscriptomics in a subset (Nose 2.0). Propidium monoazide (PMA) treatment was performed to distinguish between intact and non-intact microbiome components. The gastrointestinal microbiome of these participants was also characterized by amplicon sequencing and metabolomics and then correlated with food intake. Our results confirm that normosmics and dysosmics indeed possess a distinguishable olfactory microbiome. Alpha diversity (i.e., richness) was significantly increased in dysosmics, reflected by an increase in the number of specific taxa (e.g., Rickettsia, Spiroplasma, and Brachybacterium). Lower olfactory performance was associated with microbial signatures from the oral cavity and periodontitis (Fusobacterium, Porphyromonas, and Selenomonas). However, PMA treatment revealed a higher accumulation of dead microbial material in dysosmic subjects. The gastrointestinal microbiome partially overlapped with the nasal microbiome but did not show substantial variation with respect to olfactory performance, although the diet of dysosmic individuals was shifted toward a higher meat intake. Dysosmia is associated with a higher burden of dead microbial material in the olfactory area, indicating an impaired clearance mechanism. As the microbial community of dysosmics (hyposmics and anosmics) appears to be influenced by the oral microbiome, further studies should investigate the microbial oral-nasal interplay in individuals with partial or complete olfactory loss.IMPORTANCEThe loss of the sense of smell is an incisive event that is becoming increasingly common in today's world due to infections such as COVID-19. Although this loss usually recovers a few weeks after infection, in some cases, it becomes permanent-why is yet to be answered. Since this condition often represents a psychological burden in the long term, there is a need for therapeutic approaches. However, treatment options are limited or even not existing. Understanding the role of the microbiome in the impairment of olfaction may enable the prediction of olfactory disorders and/or could serve as a possible target for therapeutic interventions.
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Affiliation(s)
- Christina Kumpitsch
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Florian Ph. S. Fischmeister
- Department of Psychology, University of Graz, Graz, Austria
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
- BioTechMed, Graz, Austria
| | - Sonja Lackner
- Otto Loewi Research Center, Division of Immunology, Medical University of Graz, Graz, Austria
| | - Sandra Holasek
- Otto Loewi Research Center, Division of Immunology, Medical University of Graz, Graz, Austria
| | - Tobias Madl
- BioTechMed, Graz, Austria
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, Graz, Austria
| | - Hansjörg Habisch
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, Graz, Austria
| | - Axel Wolf
- Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria
| | - Veronika Schöpf
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Christine Moissl-Eichinger
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- BioTechMed, Graz, Austria
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10
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Hu B, Gong M, Xiang Y, Qu S, Zhu H, Ye D. Mechanism and treatment of olfactory dysfunction caused by coronavirus disease 2019. J Transl Med 2023; 21:829. [PMID: 37978386 PMCID: PMC10657033 DOI: 10.1186/s12967-023-04719-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Abstract
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the start of the pandemic, olfactory dysfunction (OD) has been reported as a common symptom of COVID-19. In some asymptomatic carriers, OD is often the first and even the only symptom. At the same time, persistent OD is also a long-term sequela seen after COVID-19 that can have a serious impact on the quality of life of patients. However, the pathogenesis of post-COVID-19 OD is still unclear, and there is no specific treatment for its patients. The aim of this paper was to review the research on OD caused by SARS-CoV-2 infection and to summarize the mechanism of action, the pathogenesis, and current treatments.
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Affiliation(s)
- Bian Hu
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China
- Department of Otorhinolaryngology-Head and Neck Surgery, Ninghai First Hospital, Ningbo, 315600, Zhejiang, China
| | - Mengdan Gong
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Yizhen Xiang
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Siyuan Qu
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Hai Zhu
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Dong Ye
- Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 315040, Zhejiang, China.
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11
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Ahmed W, Feng J, Zhang Y, Chen L. SARS-CoV-2 and Brain Health: New Challenges in the Era of the Pandemic. Microorganisms 2023; 11:2511. [PMID: 37894169 PMCID: PMC10609574 DOI: 10.3390/microorganisms11102511] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/13/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
Respiratory viral infections have been found to have a negative impact on neurological functions, potentially leading to significant neurological impairment. The SARS-CoV-2 virus has precipitated a worldwide pandemic, posing a substantial threat to human lives. Growing evidence suggests that SARS-CoV-2 may severely affect the CNS and respiratory system. The current prevalence of clinical neurological issues associated with SARS-CoV-2 has raised significant concerns. However, there needs to be a more comprehensive understanding of the specific pathways by which SARS-CoV-2 enters the nervous system. Based on the available evidence, this review focuses on the clinical neurological manifestations of SARS-CoV-2 and the possible mechanisms by which SARS-CoV-2 invades the brain.
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Affiliation(s)
- Waqas Ahmed
- Department of Neurosurgery, Neuroscience Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510310, China
- School of Medicine, Southeast University, Nanjing 210009, China
| | - Jia Feng
- Department of Neurosurgery, Neuroscience Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510310, China
- Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Yifan Zhang
- Department of Neurosurgery, Neuroscience Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510310, China
| | - Lukui Chen
- Department of Neurosurgery, Neuroscience Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510310, China
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12
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Sipione R, Liaudet N, Rousset F, Landis BN, Hsieh JW, Senn P. Axonal Regrowth of Olfactory Sensory Neurons In Vitro. Int J Mol Sci 2023; 24:12863. [PMID: 37629041 PMCID: PMC10454582 DOI: 10.3390/ijms241612863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
One of the most prevalent causes of olfactory loss includes traumatic brain injury with subsequent shearing of olfactory axons at the level of the cribriform plate (anterior skull base). Scar tissue at this level may prevent axonal regrowth toward the olfactory bulb. Currently, there is no cure for this debilitating and often permanent condition. One promising therapeutic concept is to implant a synthetic scaffold with growth factors through the cribriform plate/scar tissue to induce neuroregeneration. The first step toward this goal is to investigate the optimum conditions (growth factors, extracellular matrix proteins) to boost this regeneration. However, the lack of a specifically tailored in vitro model and an automated procedure for quantifying axonal length limits our ability to address this issue. The aim of this study is to create an automated quantification tool to measure axonal length and to determine the ideal growth factors and extracellular proteins to enhance axonal regrowth of olfactory sensory neurons in a mouse organotypic 2D model. We harvested olfactory epithelium (OE) of C57BL/6 mice and cultured them during 15 days on coverslips coated with various extracellular matrix proteins (Fibronectin, Collagen IV, Laminin, none) and different growth factors: fibroblast growth factor 2 (FGF2), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF), retinoic acid (RA), transforming growth factor β (TGFβ), and none. We measured the attachment rate on coverslips, the presence of cellular and axonal outgrowth, and finally, the total axonal length with a newly developed automated high-throughput quantification tool. Whereas the coatings did not influence attachment and neuronal outgrowth rates, the total axonal length was enhanced on fibronectin and collagen IV (p = 0.001). The optimum growth factor supplementation media to culture OE compared to the control condition were as follows: FGF2 alone and FGF2 from day 0 to 7 followed by FGF2 in combination with NGF from day 7 to 15 (p < 0.0001). The automated quantification tool to measure axonal length outperformed the standard Neuron J application by reducing the average analysis time from 22 to 3 min per specimen. In conclusion, robust regeneration of murine olfactory neurons in vitro can be induced, controlled, and efficiently measured using an automated quantification tool. These results will help advance the therapeutic concept closer toward preclinical studies.
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Affiliation(s)
- Rebecca Sipione
- The Inner Ear and Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland; (R.S.); (F.R.); (B.N.L.); (P.S.)
| | - Nicolas Liaudet
- Bioimaging Core Facility, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland
| | - Francis Rousset
- The Inner Ear and Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland; (R.S.); (F.R.); (B.N.L.); (P.S.)
| | - Basile N. Landis
- The Inner Ear and Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland; (R.S.); (F.R.); (B.N.L.); (P.S.)
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology—Head and Neck Surgery, Geneva University Hospitals, 4 Rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
| | - Julien Wen Hsieh
- The Inner Ear and Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland; (R.S.); (F.R.); (B.N.L.); (P.S.)
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology—Head and Neck Surgery, Geneva University Hospitals, 4 Rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
| | - Pascal Senn
- The Inner Ear and Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Rue Michel Servet 1, CH-1211 Geneva, Switzerland; (R.S.); (F.R.); (B.N.L.); (P.S.)
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology—Head and Neck Surgery, Geneva University Hospitals, 4 Rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
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13
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Song J, Wang M, Wang C, Zhang L. Olfactory dysfunction in chronic rhinosinusitis: insights into the underlying mechanisms and treatments. Expert Rev Clin Immunol 2023; 19:993-1004. [PMID: 37432663 DOI: 10.1080/1744666x.2023.2235891] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
INTRODUCTION Olfactory dysfunction (OD) is a typical symptom of chronic rhinosinusitis (CRS), which adversely affects the patient's quality of life and results in mood depression. Studies investigating the impairment of olfactory epithelium (OE) have indicated that inflammation-induced cell damage and dysfunction in OE plays a vital role in the development of OD. Consequently, glucocorticoids and biologics are beneficial in the management of OD in CRS patients. However, the mechanisms underlying OE impairment in CRS patients have not been fully elucidated. AREAS COVERED This review focuses on mechanisms underlying inflammation-induced cell impairment in OE of CRS patients. Additionally, the methods used for detection of olfaction and both currently available and potentially new clinical treatments for OD are reviewed. EXPERT OPINION Chronic inflammation in OE impairs not only olfactory sensory neurons but also non-neuronal cells that are responsible for regeneration and support for neurons. The current treatment for OD in CRS is mainly aimed at attenuating and preventing inflammation. Strategies for use of combinations of these therapies may achieve greater efficacy in restoration of the damaged OE and consequently better management of OD.
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Affiliation(s)
- Jing Song
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
| | - Ming Wang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Nasal Diseases, Beijing Laboratory of Allergic Diseases, Beijing Institute of Otolaryngology, Beijing, China
| | - Chengshuo Wang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Nasal Diseases, Beijing Laboratory of Allergic Diseases, Beijing Institute of Otolaryngology, Beijing, China
| | - Luo Zhang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Nasal Diseases, Beijing Laboratory of Allergic Diseases, Beijing Institute of Otolaryngology, Beijing, China
- Department of Allergy, Beijing TongRen Hospital, Capital Medical University, Beijing, China
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14
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Kocsis B, Pittman-Polletta B. Neuropsychiatric consequences of COVID-19 related olfactory dysfunction: could non-olfactory cortical-bound inputs from damaged olfactory bulb also contribute to cognitive impairment? Front Neurosci 2023; 17:1164042. [PMID: 37425004 PMCID: PMC10323442 DOI: 10.3389/fnins.2023.1164042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/24/2023] [Indexed: 07/11/2023] Open
Affiliation(s)
- Bernat Kocsis
- Department of Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, United States
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15
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Alvites R, Caine A, Cherubini GB, Prada J, Varejão ASP, Maurício AC. The Olfactory Bulb in Companion Animals-Anatomy, Physiology, and Clinical Importance. Brain Sci 2023; 13:brainsci13050713. [PMID: 37239185 DOI: 10.3390/brainsci13050713] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/13/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
The Olfactory Bulb is a component of the Olfactory System, in which it plays an essential role as an interface between the peripheral components and the cerebral cortex responsible for olfactory interpretation and discrimination. It is in this element that the first selective integration of olfactory stimuli occurs through a complex cell interaction that forwards the received olfactory information to higher cortical centers. Considering its position in the organizational hierarchy of the olfactory system, it is now known that changes in the Olfactory Bulb can lead to olfactory abnormalities. Through imaging techniques, it was possible to establish relationships between the occurrence of changes secondary to brain aging and senility, neurodegenerative diseases, head trauma, and infectious diseases with a decrease in the size of the Olfactory Bulb and in olfactory acuity. In companion animals, this relationship has also been identified, with observations of relations between the cranial conformation, the disposition, size, and shape of the Olfactory Bulb, and the occurrence of structural alterations associated with diseases with different etiologies. However, greater difficulty in quantitatively assessing olfactory acuity in animals and a manifestly smaller number of studies dedicated to this topic maintain a lack of concrete and unequivocal results in this field of veterinary sciences. The aim of this work is to revisit the Olfactory Bulb in companion animals in all its dimensions, review its anatomy and histological characteristics, physiological integration in the olfactory system, importance as a potential early indicator of the establishment of specific pathologies, as well as techniques of imaging evaluation for its in vivo clinical exploration.
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Affiliation(s)
- Rui Alvites
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Rua D. Manuel II, Apartado 55142, 4051-401 Porto, Portugal
- Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), 1300-477 Lisboa, Portugal
- Instituto Universitário de Ciências da Saúde (CESPU), Avenida Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Abby Caine
- Dick White Referrals, Station Farm, London Road, Six Mile Bottom, Cambridgeshire CB8 0UH, UK
| | - Giunio Bruto Cherubini
- Department of Veterinary Sciences, Veterinary Teaching Hospital "Mario Modenato", University of Pisa, Via Livornese Lato Monte, San Piero a Grado, 56122 Pisa, Italy
| | - Justina Prada
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), 1300-477 Lisboa, Portugal
- Centro de Ciência Animal e Veterinária (CECAV), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal
- Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal
| | - Artur Severo P Varejão
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), 1300-477 Lisboa, Portugal
- Centro de Ciência Animal e Veterinária (CECAV), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal
- Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal
| | - Ana Colette Maurício
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Rua D. Manuel II, Apartado 55142, 4051-401 Porto, Portugal
- Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), 1300-477 Lisboa, Portugal
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16
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Tan ZW, Toong PJ, Guarnera E, Berezovsky IN. Disrupted chromatin architecture in olfactory sensory neurons: looking for the link from COVID-19 infection to anosmia. Sci Rep 2023; 13:5906. [PMID: 37041182 PMCID: PMC10088727 DOI: 10.1038/s41598-023-32896-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 04/04/2023] [Indexed: 04/13/2023] Open
Abstract
We tackle here genomic mechanisms of a rapid onset and recovery from anosmia-a potential diagnostic indicator for early-stage COVID-19 infection. Based on previous observations on how olfactory receptor (OR) gene expression is regulated via chromatin structure in mice, we hypothesized that the disruption of the OR gene expression and, respectively, deficiency of the OR function can be caused by chromatin reorganization taking place upon SARS-CoV-2 infection. We obtained chromatin ensemble reconstructions from COVID-19 patients and control samples using our original computational framework for the whole-genome 3D chromatin ensemble reconstruction. Specifically, we used megabase-scale structural units and effective interactions between them obtained in the Markov State modelling of the Hi-C contact network as an unput in the stochastic embedding procedure of the whole-genome 3D chromatin ensemble reconstruction. We have also developed here a new procedure for analyzing fine structural hierarchy with (sub)TAD-size units in local chromatin regions, which we apply here to parts of chromosomes containing OR genes and corresponding regulatory elements. We observed structural modifications in COVID-19 patients on different levels of chromatin organization, from the alteration of whole genome structure and chromosomal intermingling to reorganization of contacts between chromatin loops at the level of topologically associating domains. While complementary data on known regulatory elements point to potential pathology-associated changes within the overall picture of chromatin alterations, further investigation using additional epigenetic factors mapped on 3D reconstructions with improved resolution will be required for better understanding of anosmia caused by SARS-CoV-2 infection.
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Affiliation(s)
- Zhen Wah Tan
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street, Matrix, Singapore, 138671, Republic of Singapore
| | - Ping Jing Toong
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street, Matrix, Singapore, 138671, Republic of Singapore
| | - Enrico Guarnera
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street, Matrix, Singapore, 138671, Republic of Singapore
- Computational Drug Discovery, EMD Serono Research and Development Institute, Merck KGaA, 45A Middlesex Tpke, Billerica, MA, 01821, USA
| | - Igor N Berezovsky
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street, Matrix, Singapore, 138671, Republic of Singapore.
- Department of Biological Sciences (DBS), National University of Singapore (NUS), 8 Medical Drive, Singapore, 117597, Singapore.
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17
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Zhao X, Liu G, Yu X, Yang X, Gao W, Zhao Z, Ma T, Ma J. Ablation of AQP5 gene in mice leads to olfactory dysfunction caused by hyposecretion of Bowman's gland. Chem Senses 2023; 48:bjad030. [PMID: 37586060 DOI: 10.1093/chemse/bjad030] [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: 11/20/2022] [Indexed: 08/18/2023] Open
Abstract
Smell detection depends on nasal airflow, which can make absorption of odors to the olfactory epithelium by diffusion through the mucus layer. The odors then act on the chemo-sensitive epithelium of olfactory sensory neurons (OSNs). Therefore, any pathological changes in the olfactory area, for instance, dry nose caused by Sjögren's Syndrome (SS) may interfere with olfactory function. SS is an autoimmune disease in which aquaporin (AQP) 5 autoantibodies have been detected in the serum. However, the expression of AQP5 in olfactory mucosa and its function in olfaction is still unknown. Based on the study of the expression characteristics of AQP5 protein in the nasal mucosa, the olfaction dysfunction in AQP5 knockout (KO) mice was found by olfactory behavior analysis, which was accompanied by reduced secretion volume of Bowman's gland by using in vitro secretion measure system, and the change of acid mucin in nasal mucus layer was identified. By excluding the possibility that olfactory disturbance was caused by changes in OSNs, the result indicated that AQP5 contributes to olfactory functions by regulating the volume and composition of OE mucus layer, which is the medium for the dissolution of odor molecules. Our results indicate that AQP5 can affect the olfactory functions by regulating the water supply of BGs and the mucus layer upper the OE that can explain the olfactory loss in the patients of SS, and AQP5 KO mice might be used as an ideal model to study the olfactory dysfunction.
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Affiliation(s)
- Xinnan Zhao
- Department of Anatomy, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Gang Liu
- Department of Anatomy, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Xin Yu
- The High School Attached to Northeast Normal University, Changchun, Jilin, China
| | - Xiaohan Yang
- Department of Anatomy, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
- Department of Morphology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Wenting Gao
- Institute of Genome Engineered Animal Models for Human Disease, National Center of Genetically Engineered Animal Models, College of Integrative Medicine, Dalian Medical University, Dalian, Liaoning, China
| | - Zinan Zhao
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
| | - Tonghui Ma
- National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
- School of Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Jianmei Ma
- Department of Anatomy, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning, China
- National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
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18
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Butowt R, Bilinska K, von Bartheld CS. Olfactory dysfunction in COVID-19: new insights into the underlying mechanisms. Trends Neurosci 2023; 46:75-90. [PMID: 36470705 PMCID: PMC9666374 DOI: 10.1016/j.tins.2022.11.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/06/2022] [Accepted: 11/14/2022] [Indexed: 11/17/2022]
Abstract
The mechanisms of olfactory dysfunction in COVID-19 are still unclear. In this review, we examine potential mechanisms that may explain why the sense of smell is lost or altered. Among the current hypotheses, the most plausible is that death of infected support cells in the olfactory epithelium causes, besides altered composition of the mucus, retraction of the cilia on olfactory receptor neurons, possibly because of the lack of support cell-derived glucose in the mucus, which powers olfactory signal transduction within the cilia. This mechanism is consistent with the rapid loss of smell with COVID-19, and its rapid recovery after the regeneration of support cells. Host immune responses that cause downregulation of genes involved in olfactory signal transduction occur too late to trigger anosmia, but may contribute to the duration of the olfactory dysfunction.
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Affiliation(s)
- Rafal Butowt
- Global Consortium of Chemosensory Research - Poland, Przybory Str 3/2, 85-791 Bydgoszcz, Poland
| | - Katarzyna Bilinska
- Department of Molecular Cell Genetics, L. Rydygier Collegium Medicum, Nicolaus Copernicus University, uI. Curie Sklodowskiej 9, 85-94, Bydgoszcz, Poland.
| | - Christopher S von Bartheld
- Center of Biomedical Research Excellence in Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557-0352, USA; Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557-0352, USA.
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19
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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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20
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Shahbaz MA, De Bernardi F, Alatalo A, Sachana M, Clerbaux LA, Muñoz A, Parvatam S, Landesmann B, Kanninen KM, Coecke S. Mechanistic Understanding of the Olfactory Neuroepithelium Involvement Leading to Short-Term Anosmia in COVID-19 Using the Adverse Outcome Pathway Framework. Cells 2022; 11:3027. [PMID: 36230989 PMCID: PMC9563945 DOI: 10.3390/cells11193027] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/09/2022] [Accepted: 09/19/2022] [Indexed: 12/23/2022] Open
Abstract
Loss of the sense of smell (anosmia) has been included as a COVID-19 symptom by the World Health Organization. The majority of patients recover the sense of smell within a few weeks postinfection (short-term anosmia), while others report persistent anosmia. Several studies have investigated the mechanisms leading to anosmia in COVID-19; however, the evidence is scattered, and the mechanisms remain poorly understood. Based on a comprehensive review of the literature, we aim here to evaluate the current knowledge and uncertainties regarding the mechanisms leading to short-term anosmia following SARS-CoV-2 infection. We applied an adverse outcome pathway (AOP) framework, well established in toxicology, to propose a sequence of measurable key events (KEs) leading to short-term anosmia in COVID-19. Those KEs are (1) SARS-CoV-2 Spike proteins binding to ACE-2 expressed by the sustentacular (SUS) cells in the olfactory epithelium (OE); (2) viral entry into SUS cells; (3) viral replication in the SUS cells; (4) SUS cell death; (5) damage to the olfactory sensory neurons and the olfactory epithelium (OE). This AOP-aligned approach allows for the identification of gaps where more research should be conducted and where therapeutic intervention could act. Finally, this AOP gives a frame to explain several disease features and can be linked to specific factors that lead to interindividual differences in response to SARS-CoV-2 infection.
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Affiliation(s)
- Muhammad Ali Shahbaz
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Francesca De Bernardi
- Division of Otorhinolaryngology, Department of Biotechnologies and Life Sciences, University of Insubria, Ospedale di Circolo e Fondazione Macchi, 21100 Varese, Italy
| | - Arto Alatalo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Magdalini Sachana
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Cooperation and Development (OECD), 75775 Paris, France
| | | | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | - Surat Parvatam
- Centre for Predictive Human Model Systems, Atal Incubation Centre-Centre for Cellular and Molecular Biology (AIC-CCMB), Habsiguda, Hyderabad 500039, India
| | | | - Katja M. Kanninen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
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21
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COVID-19, sens chimiques et pathologies métaboliques. MÉDECINE DES MALADIES MÉTABOLIQUES 2022. [PMCID: PMC9433342 DOI: 10.1016/j.mmm.2022.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Une réduction importante de l’odorat, indépendamment de l’obstruction nasale, et du goût, a été signalée comme un des symptômes majeurs suite à l’infection par la COVID-19. Cette réduction est si fréquente qu’elle a été proposée comme un des prédicteurs le plus relevant pour diagnostiquer l’infection. Différents mécanismes par lesquels les virus affectent l’odorat et le goût ont été proposés. L’ACE2 (enzyme de conversion de l’angiotensine 2) a été caractérisé comme le principal récepteur d’entrée du virus SARS-CoV-2 qui interagit avec les protéines « spikes » du virus, ce qui permet à ce dernier d’entrer dans la cellule hôte par un domaine de fusion. Il est principalement exprimé dans la partie supérieure des voies respiratoires, et la plus forte densité de ces protéines se trouve dans les épithéliums olfactif et gustatif. Les données actuellement disponibles indiquent que la cause la plus probable de l’anosmie pendant la COVID-19 est une altération de la fonction des neurones sensoriels olfactifs, associée à l’infection et à la mort des cellules microvillaires, et des péricytes vasculaires. Les mécanismes généraux sont les mêmes en ce qui concerne le goût. La pathogenèse des troubles olfactifs et gustatifs dans la COVID-19 peut entraîner des altérations diverses, dont des modifications de la prise alimentaire et du métabolisme énergétique. Les individus porteurs de pathologies métaboliques ayant une plus forte susceptibilité à la COVID-19 sont, de ce fait, plus exposés aux perturbations des sens chimiques et à leurs conséquences. De plus, des études récentes montrent que la COVID-19 augmenterait la susceptibilité au diabète en s’attaquant directement aux cellules β-pancréatiques.
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22
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When is a neuron like an epithelial cell. Dev Biol 2022; 489:161-164. [DOI: 10.1016/j.ydbio.2022.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/18/2022] [Indexed: 11/30/2022]
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Ziuzia-Januszewska L, Januszewski M. Pathogenesis of Olfactory Disorders in COVID-19. Brain Sci 2022; 12:brainsci12040449. [PMID: 35447981 PMCID: PMC9029941 DOI: 10.3390/brainsci12040449] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/09/2022] [Accepted: 03/23/2022] [Indexed: 12/11/2022] Open
Abstract
Since the outbreak of the SARS-CoV-2 pandemic, olfactory disorders have been reported as a frequent symptom of COVID-19; however, its pathogenesis is still debated. The aim of this review is to summarize the current understanding of the pathogenesis of smell impairment in the course of COVID-19 and to highlight potential avenues for future research on this issue. Several theories have been proposed to explain the pathogenesis of COVID-19-related anosmia, including nasal obstruction and rhinorrhea, oedema of the olfactory cleft mucosa, olfactory epithelial damage either within the olfactory receptor cells or the supporting non-neural cells (either direct or immune-mediated), damage to the olfactory bulb, and impairment of the central olfactory pathways. Although the pathogenesis of COVID-19-related anosmia is still not fully elucidated, it appears to be mainly due to sensorineural damage, with infection of the olfactory epithelium support cells via the ACE1 receptor and disruption of the OE caused by immense inflammatory reaction, and possibly with direct olfactory sensory neurons infection mediated by the NRP-1 receptor. Involvement of the higher olfactory pathways and a conductive component of olfactory disorders, as well as genetic factors, may also be considered.
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Affiliation(s)
- Laura Ziuzia-Januszewska
- Department of Otolaryngology, Central Clinical Hospital, Ministry of Interior and Administration, 02-507 Warsaw, Poland
- Correspondence: or ; Tel.: +48-477221182
| | - Marcin Januszewski
- Department of Obstetrics and Gynecology, Central Clinical Hospital, Ministry of Interior and Administration, 02-507 Warsaw, Poland;
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Ojha P, Dixit A. Olfactory training for Olfactory dysfunction in COVID-19: A promising mitigation amidst looming neurocognitive sequelae of the pandemic. Clin Exp Pharmacol Physiol 2022; 49:462-473. [PMID: 35090056 DOI: 10.1111/1440-1681.13626] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/15/2021] [Accepted: 12/02/2021] [Indexed: 12/01/2022]
Abstract
Olfactory dysfunction (OD) is a recognized symptom of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is independently associated with neurodegenerative disorders. Moreover, the central nervous system manifestations in patients infected with the coronavirus -2019 (COVID-19) have demonstrated cognitive decline and neuropsychiatric manifestations. Hence, OD in COVID -19 necessitates perusal of its' mechanism and available treatment options to avert possible development of neurocognitive sequelae of the pandemic. The article presents a literature review organized from the published information about olfactory training (OT) for OD during COVID-19. The methodology comprised retrieval of available literature from database searches and subsequent scrutinization of relevant information. Inferentially, Injury to the sustentacular cells, possessing angiotensin-converting enzyme 2 (ACE-2) receptors, is an important mechanism causing OD in COVID-19. OD may be prolonged in severe cases of anosmia predisposing to neurodegenerative and cognitive impairment in COVID-19 infection. OT demonstrates an effective treatment for OD based on human and animal-derived evidence through recent studies. It curtails the progression of OD, besides inducing neural rearrangement and changes in functional connectivity in patients receiving OT. Additionally, contemporary reports support that the administration of OT for COVID-induced anosmia is effective and encompasses no significant adverse effects. The present review highlights the prominence of olfactory training as a recommended intervention for OD in COVID-19. This review can guide the clinicians in curbing neurological repercussions of COVID besides enhancing cognitive rehabilitation through olfactory training.
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Affiliation(s)
- Pooja Ojha
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Abhinav Dixit
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
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Butowt R, von Bartheld CS. Anosmia in COVID-19: Underlying Mechanisms and Assessment of an Olfactory Route to Brain Infection. Neuroscientist 2021; 27:582-603. [PMID: 32914699 PMCID: PMC7488171 DOI: 10.1177/1073858420956905] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In recent months it has emerged that the novel coronavirus-responsible for the COVID-19 pandemic-causes reduction of smell and taste in a large fraction of patients. The chemosensory deficits are often the earliest, and sometimes the only signs in otherwise asymptomatic carriers of the SARS-CoV-2 virus. The reasons for the surprisingly early and specific chemosensory dysfunction in COVID-19 are now beginning to be elucidated. In this hypothesis review, we discuss implications of the recent finding that the prevalence of smell and taste dysfunction in COVID-19 patients differs between populations, possibly because of differences in the spike protein of different virus strains or because of differences in the host proteins that enable virus entry, thus modifying infectivity. We review recent progress in defining underlying cellular and molecular mechanisms of the virus-induced anosmia, with a focus on the emerging crucial role of sustentacular cells in the olfactory epithelium. We critically examine the current evidence whether and how the SARS-CoV-2 virus can follow a route from the olfactory epithelium in the nose to the brain to achieve brain infection, and we discuss the prospects for using the smell and taste dysfunctions seen in COVID-19 as an early and rapid diagnostic screening tool.
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Affiliation(s)
- Rafal Butowt
- Department of Molecular Cell Genetics, L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
- Department of Anatomy, L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Christopher S. von Bartheld
- Center of Biomedical Research Excellence in Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, USA
- Department of Physiology and Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, USA
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Khan M, Yoo SJ, Clijsters M, Backaert W, Vanstapel A, Speleman K, Lietaer C, Choi S, Hether TD, Marcelis L, Nam A, Pan L, Reeves JW, Van Bulck P, Zhou H, Bourgeois M, Debaveye Y, De Munter P, Gunst J, Jorissen M, Lagrou K, Lorent N, Neyrinck A, Peetermans M, Thal DR, Vandenbriele C, Wauters J, Mombaerts P, Van Gerven L. Visualizing in deceased COVID-19 patients how SARS-CoV-2 attacks the respiratory and olfactory mucosae but spares the olfactory bulb. Cell 2021; 184:5932-5949.e15. [PMID: 34798069 PMCID: PMC8564600 DOI: 10.1016/j.cell.2021.10.027] [Citation(s) in RCA: 224] [Impact Index Per Article: 74.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/01/2021] [Accepted: 10/25/2021] [Indexed: 12/28/2022]
Abstract
Anosmia, the loss of smell, is a common and often the sole symptom of COVID-19. The onset of the sequence of pathobiological events leading to olfactory dysfunction remains obscure. Here, we have developed a postmortem bedside surgical procedure to harvest endoscopically samples of respiratory and olfactory mucosae and whole olfactory bulbs. Our cohort of 85 cases included COVID-19 patients who died a few days after infection with SARS-CoV-2, enabling us to catch the virus while it was still replicating. We found that sustentacular cells are the major target cell type in the olfactory mucosa. We failed to find evidence for infection of olfactory sensory neurons, and the parenchyma of the olfactory bulb is spared as well. Thus, SARS-CoV-2 does not appear to be a neurotropic virus. We postulate that transient insufficient support from sustentacular cells triggers transient olfactory dysfunction in COVID-19. Olfactory sensory neurons would become affected without getting infected.
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Affiliation(s)
- Mona Khan
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Seung-Jun Yoo
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Marnick Clijsters
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium
| | - Wout Backaert
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Unit, KU Leuven, Leuven, Belgium
| | - Arno Vanstapel
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Kato Speleman
- Department of Otorhinolaryngology, Head and Neck Surgery, AZ Sint-Jan Brugge-Oostende AV, Bruges, Belgium
| | - Charlotte Lietaer
- Department of Otorhinolaryngology, Head and Neck Surgery, AZ Sint-Jan Brugge-Oostende AV, Bruges, Belgium
| | - Sumin Choi
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | | | - Lukas Marcelis
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Andrew Nam
- NanoString Technologies Inc., Seattle, WA, USA
| | - Liuliu Pan
- NanoString Technologies Inc., Seattle, WA, USA
| | | | - Pauline Van Bulck
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Hai Zhou
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Marc Bourgeois
- Department of Anesthesiology and Intensive Care Medicine, AZ Sint-Jan Brugge-Oostende AV, Bruges, Belgium
| | - Yves Debaveye
- Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, Laboratory of Intensive Care Medicine, KU Leuven, Leuven, Belgium
| | - Paul De Munter
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Jan Gunst
- Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, Laboratory of Intensive Care Medicine, KU Leuven, Leuven, Belgium
| | - Mark Jorissen
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium; Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Katrien Lagrou
- Department of Laboratory Medicine and National Reference Centre for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, KU Leuven, Leuven, Belgium
| | - Natalie Lorent
- Department of Respiratory Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Arne Neyrinck
- Department of Anesthesia, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Marijke Peetermans
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium; Department of Imaging and Pathology, Laboratory of Neuropathology and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Christophe Vandenbriele
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Joost Wauters
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Peter Mombaerts
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany.
| | - Laura Van Gerven
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium; Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Unit, KU Leuven, Leuven, Belgium.
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Wan D, Du T, Hong W, Chen L, Que H, Lu S, Peng X. Neurological complications and infection mechanism of SARS-COV-2. Signal Transduct Target Ther 2021; 6:406. [PMID: 34815399 PMCID: PMC8609271 DOI: 10.1038/s41392-021-00818-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 09/27/2021] [Accepted: 11/02/2021] [Indexed: 02/05/2023] Open
Abstract
Currently, SARS-CoV-2 has caused a global pandemic and threatened many lives. Although SARS-CoV-2 mainly causes respiratory diseases, growing data indicate that SARS-CoV-2 can also invade the central nervous system (CNS) and peripheral nervous system (PNS) causing multiple neurological diseases, such as encephalitis, encephalopathy, Guillain-Barré syndrome, meningitis, and skeletal muscular symptoms. Despite the increasing incidences of clinical neurological complications of SARS-CoV-2, the precise neuroinvasion mechanisms of SARS-CoV-2 have not been fully established. In this review, we primarily describe the clinical neurological complications associated with SARS-CoV-2 and discuss the potential mechanisms through which SARS-CoV-2 invades the brain based on the current evidence. Finally, we summarize the experimental models were used to study SARS-CoV-2 neuroinvasion. These data form the basis for studies on the significance of SARS-CoV-2 infection in the brain.
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Affiliation(s)
- Dandan Wan
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatricts, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, 610041, Chengdu, Sichuan, PR China
| | - Tingfu Du
- National Kunming High-level Biosafety Primate Research Center, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan, China
| | - Weiqi Hong
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatricts, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, 610041, Chengdu, Sichuan, PR China
| | - Li Chen
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatricts, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, 610041, Chengdu, Sichuan, PR China
| | - Haiying Que
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatricts, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, 610041, Chengdu, Sichuan, PR China
| | - Shuaiyao Lu
- National Kunming High-level Biosafety Primate Research Center, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan, China.
| | - Xiaozhong Peng
- National Kunming High-level Biosafety Primate Research Center, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan, China.
- State Key Laboratory of Medical Molecular Biology, Department of Molecular, Biology and Biochemistry, Institute of Basic Medical Sciences, Medical Primate Research Center, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China.
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28
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COVID-19 Anosmia: High Prevalence, Plural Neuropathogenic Mechanisms, and Scarce Neurotropism of SARS-CoV-2? Viruses 2021; 13:v13112225. [PMID: 34835030 PMCID: PMC8625547 DOI: 10.3390/v13112225] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 12/14/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of coronavirus disease 2019 (COVID-19). It is known as a respiratory virus, but SARS-CoV-2 appears equally, or even more, infectious for the olfactory epithelium (OE) than for the respiratory epithelium in the nasal cavity. In light of the small area of the OE relative to the respiratory epithelium, the high prevalence of olfactory dysfunctions (ODs) in COVID-19 has been bewildering and has attracted much attention. This review aims to first examine the cytological and molecular biological characteristics of the OE, especially the microvillous apical surfaces of sustentacular cells and the abundant SARS-CoV-2 receptor molecules thereof, that may underlie the high susceptibility of this neuroepithelium to SARS-CoV-2 infection and damages. The possibility of SARS-CoV-2 neurotropism, or the lack of it, is then analyzed with regard to the expression of the receptor (angiotensin-converting enzyme 2) or priming protease (transmembrane serine protease 2), and cellular targets of infection. Neuropathology of COVID-19 in the OE, olfactory bulb, and other related neural structures are also reviewed. Toward the end, we present our perspectives regarding possible mechanisms of SARS-CoV-2 neuropathogenesis and ODs, in the absence of substantial viral infection of neurons. Plausible causes for persistent ODs in some COVID-19 convalescents are also examined.
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29
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Kokocińska-Kusiak A, Woszczyło M, Zybala M, Maciocha J, Barłowska K, Dzięcioł M. Canine Olfaction: Physiology, Behavior, and Possibilities for Practical Applications. Animals (Basel) 2021; 11:ani11082463. [PMID: 34438920 PMCID: PMC8388720 DOI: 10.3390/ani11082463] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/03/2021] [Accepted: 08/19/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Dogs have an extraordinary olfactory capability, which far exceeds that of humans. Dogs’ sense of smell seems to be the main sense, allowing them to not only gather both current and historical information about their surrounding environment, but also to find the source of the smell, which is crucial for locating food, danger, or partners for reproduction. Dogs can be trained by humans to use their olfactory abilities in a variety of fields, with a detection limit often much lower than that of sophisticated laboratory instruments. The specific anatomical and physiological features of dog olfaction allow humans to achieve outstanding results in the detection of drugs, explosives, and different illnesses, such as cancer, diabetes, or infectious disease. This article provides an overview of the anatomical features and physiological mechanisms involved in the process of odor detection and identification, as well as behavioral aspects of canine olfaction and its use in the service of humans in many fields. Abstract Olfaction in dogs is crucial for gathering important information about the environment, recognizing individuals, making decisions, and learning. It is far more specialized and sensitive than humans’ sense of smell. Using the strength of dogs’ sense of smell, humans work with dogs for the recognition of different odors, with a precision far exceeding the analytical capabilities of most modern instruments. Due to their extremely sensitive sense of smell, dogs could be used as modern, super-sensitive mobile area scanners, detecting specific chemical signals in real time in various environments outside the laboratory, and then tracking the odor of dynamic targets to their source, also in crowded places. Recent studies show that dogs can detect not only specific scents of drugs or explosives, but also changes in emotions as well as in human cell metabolism during various illnesses, including COVID-19 infection. Here, we provide an overview of canine olfaction, discussing aspects connected with anatomy, physiology, behavioral aspects of sniffing, and factors influencing the olfactory abilities of the domestic dog (Canis familiaris).
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Affiliation(s)
- Agata Kokocińska-Kusiak
- Institute of Animal Sciences, Warsaw University of Life Sciences, ul. Ciszewskiego 8, 02-786 Warszawa, Poland; (A.K.-K.); (J.M.)
| | - Martyna Woszczyło
- Department of Reproduction and Clinic of Farm Animals, Wroclaw University of Environmental and Life Sciences, Plac Grunwaldzki 49, 50-366 Wrocław, Poland;
| | - Mikołaj Zybala
- Institute of Biological Sciences, Doctoral School, Siedlce University of Natural Sciences and Humanities, ul. Konarskiego 2, 08-110 Siedlce, Poland;
| | - Julia Maciocha
- Institute of Animal Sciences, Warsaw University of Life Sciences, ul. Ciszewskiego 8, 02-786 Warszawa, Poland; (A.K.-K.); (J.M.)
| | - Katarzyna Barłowska
- Department of Biotechnology and Nutrigenomics, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, 05-552 Magdalenka, Poland;
| | - Michał Dzięcioł
- Department of Reproduction and Clinic of Farm Animals, Wroclaw University of Environmental and Life Sciences, Plac Grunwaldzki 49, 50-366 Wrocław, Poland;
- Correspondence:
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Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
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Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
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Bilinska K, von Bartheld CS, Butowt R. Expression of the ACE2 Virus Entry Protein in the Nervus Terminalis Reveals the Potential for an Alternative Route to Brain Infection in COVID-19. Front Cell Neurosci 2021; 15:674123. [PMID: 34290590 PMCID: PMC8287262 DOI: 10.3389/fncel.2021.674123] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 06/09/2021] [Indexed: 12/11/2022] Open
Abstract
Previous studies suggested that the SARS-CoV-2 virus may gain access to the brain by using a route along the olfactory nerve. However, there is a general consensus that the obligatory virus entry receptor, angiotensin converting enzyme 2 (ACE2), is not expressed in olfactory receptor neurons, and the timing of arrival of the virus in brain targets is inconsistent with a neuronal transfer along olfactory projections. We determined whether nervus terminalis neurons and their peripheral and central projections should be considered as a potential alternative route from the nose to the brain. Nervus terminalis neurons in postnatal mice were double-labeled with antibodies against ACE2 and two nervus terminalis markers, gonadotropin-releasing hormone (GnRH) and choline acetyltransferase (CHAT). We show that a small fraction of CHAT-labeled nervus terminalis neurons, and the large majority of GnRH-labeled nervus terminalis neurons with cell bodies in the region between the olfactory epithelium and the olfactory bulb express ACE2 and cathepsins B and L. Nervus terminalis neurons therefore may provide a direct route for the virus from the nasal epithelium, possibly via innervation of Bowman's glands, to brain targets, including the telencephalon and diencephalon. This possibility needs to be examined in suitable animal models and in human tissues.
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Affiliation(s)
- Katarzyna Bilinska
- L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Christopher S. von Bartheld
- Department of Physiology and Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, United States
| | - Rafal Butowt
- L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
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32
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Can SARS-CoV-2 infect the central nervous system via the olfactory bulb or the blood-brain barrier? Brain Behav Immun 2021; 95:7-14. [PMID: 33412255 PMCID: PMC7836942 DOI: 10.1016/j.bbi.2020.12.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/17/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China in December 2019. On February 11, the World Health Organization (WHO) announced the name for the new illness caused by SARS-CoV-2: COVID-19. By March 11, the outbreak of COVID-19 was declared a pandemic by the WHO. This virus has extensively altered daily life for many across the globe, while claiming hundreds of thousands of lives. While fundamentally a respiratory illness, many infected individuals experience symptoms that involve the central nervous system (CNS). It is likely that many of these symptoms are the result of the virus residing outside of the CNS. However, the current evidence does indicate that the SARS-CoV-2 virus can use olfactory neurons (or other nerve tracts) to travel from the periphery into the CNS, and that the virus may also enter the brain through the blood-brain barrier (BBB). We discuss how the virus may use established infection mechanisms (ACE2, NRP1, TMPRSS2, furin and Cathepsin L), as well mechanisms still under consideration (BASIGIN) to infect and spread throughout the CNS. Confirming the impact of the virus on the CNS will be crucial in dealing with the long-term consequences of the epidemic.
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Xu Y, Zhuang Y, Kang L. A Review of Neurological Involvement in Patients with SARS-CoV-2 Infection. Med Sci Monit 2021; 27:e932962. [PMID: 34145211 PMCID: PMC8221270 DOI: 10.12659/msm.932962] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 05/31/2021] [Indexed: 02/06/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of the recent pandemic of coronavirus disease 19 (COVID-19). As the infection spreads, there is increasing evidence of neurological and psychiatric involvement in COVID-19. Headache, impaired consciousness, and olfactory and gustatory dysfunctions are common neurological manifestations described in the literature. Studies demonstrating more specific and more severe neurological involvement such as cerebrovascular insults, encephalitis and Guillain-Barre syndrome are also emerging. Respiratory failure, a significant condition that leads to mortality in COVID-19, is hypothesized to be partly due to brainstem impairment. Notably, some of these neurological complications seem to persist long after infection. This review aims to provide an update on what is currently known about neurological involvement in patients with COVID-19 due to SARS-CoV-2 infection. In this review, we demonstrate invasion routes of SARS-CoV-2, provide evidence to support the neurotropism hypothesis of the virus, and investigate the pathological mechanisms that underlie neurological complications associated with SARS-CoV-2.
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Affiliation(s)
- Yidan Xu
- Jiangxi Key Laboratory of Experimental Animals, Nanchang University, Nanchang, Jiangxi, P.R. China
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Yu Zhuang
- Jiangxi Key Laboratory of Experimental Animals, Nanchang University, Nanchang, Jiangxi, P.R. China
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Lumei Kang
- Jiangxi Key Laboratory of Experimental Animals, Nanchang University, Nanchang, Jiangxi, P.R. China
- Department of Animal Science, Medical College, Nanchang University, Nanchang, Jiangxi, P.R. China
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Bilinska K, von Bartheld CS, Butowt R. Expression of the ACE2 virus entry protein in the nervus terminalis reveals the potential for an alternative route to brain infection in COVID-19. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.04.11.439398. [PMID: 33880469 PMCID: PMC8057234 DOI: 10.1101/2021.04.11.439398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previous studies suggested that the SARS-CoV-2 virus may gain access to the brain by using a route along the olfactory nerve. However, there is a general consensus that the obligatory virus entry receptor, angiotensin converting enzyme 2 (ACE2), is not expressed in olfactory receptor neurons, and the timing of arrival of the virus in brain targets is inconsistent with a neuronal transfer along olfactory projections. We determined whether nervus terminalis neurons and their peripheral and central projections should be considered as a potential alternative route from the nose to the brain. Nervus terminalis neurons in postnatal mice were double-labeled with antibodies against ACE2 and two nervus terminalis markers, gonadotropin-releasing hormone (GnRH) and choline acetyltransferase (CHAT). We show that a small fraction of CHAT-labeled nervus terminalis neurons, and the large majority of GnRH-labeled nervus terminalis neurons with cell bodies in the region between the olfactory epithelium and the olfactory bulb express ACE2 and cathepsins B and L. Nervus terminalis neurons therefore may provide a direct route for the virus from the nasal epithelium, possibly via innervation of Bowman's glands, to brain targets, including the telencephalon and diencephalon. This possibility needs to be examined in suitable animal models and in human tissues.
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Affiliation(s)
- Katarzyna Bilinska
- L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Christopher S. von Bartheld
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, United States
| | - Rafal Butowt
- L. Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
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Butowt R, Meunier N, Bryche B, von Bartheld CS. The olfactory nerve is not a likely route to brain infection in COVID-19: a critical review of data from humans and animal models. Acta Neuropathol 2021; 141:809-822. [PMID: 33903954 PMCID: PMC8075028 DOI: 10.1007/s00401-021-02314-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022]
Abstract
One of the most frequent symptoms of COVID-19 is the loss of smell and taste. Based on the lack of expression of the virus entry proteins in olfactory receptor neurons, it was originally assumed that the new coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) does not infect olfactory neurons. Recent studies have reported otherwise, opening the possibility that the virus can directly infect the brain by traveling along the olfactory nerve. Multiple animal models have been employed to assess mechanisms and routes of brain infection of SARS-CoV-2, often with conflicting results. We here review the current evidence for an olfactory route to brain infection and conclude that the case for infection of olfactory neurons is weak, based on animal and human studies. Consistent brain infection after SARS-CoV-2 inoculation in mouse models is only seen when the virus entry proteins are expressed abnormally, and the timeline and progression of rare neuro-invasion in these and in other animal models points to alternative routes to the brain, other than along the olfactory projections. COVID-19 patients can be assured that loss of smell does not necessarily mean that the SARS-CoV-2 virus has gained access to and has infected their brains.
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Affiliation(s)
- Rafal Butowt
- L. Rydygier Collegium Medicum, Nicolaus Copernicus University, 85-094, Bydgoszcz, Poland.
| | - Nicolas Meunier
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Bertrand Bryche
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Christopher S von Bartheld
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno, NV, 89557, USA.
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The Intersection of Parkinson's Disease, Viral Infections, and COVID-19. Mol Neurobiol 2021; 58:4477-4486. [PMID: 34033061 PMCID: PMC8143990 DOI: 10.1007/s12035-021-02408-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/27/2021] [Indexed: 02/08/2023]
Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of human COVID-19, not only causes flu-like symptoms and gut microbiome complications but a large number of infected individuals also experience a host of neurological symptoms including loss of smell and taste, seizures, difficulty concentrating, decreased alertness, and brain inflammation. Although SARS-CoV-2 infections are not more prevalent in Parkinson’s disease patients, a higher mortality rate has been reported not only associated with older age and longer disease duration, but also through several mechanisms, such as interactions with the brain dopaminergic system and through systemic inflammatory responses. Indeed, a number of the neurological symptoms seen in COVID-19 patients, as well as the alterations in the gut microbiome, are also prevalent in patients with Parkinson’s disease. Furthermore, biochemical pathways such as oxidative stress, inflammation, and protein aggregation have shared commonalities between Parkinson’s disease and COVID-19 disease progression. In this review, we describe and compare the numerous similarities and intersections between neurodegeneration in Parkinson’s disease and RNA viral infections, emphasizing the current SARS-CoV-2 global health crisis.
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Bryche B, Baly C, Meunier N. Modulation of olfactory signal detection in the olfactory epithelium: focus on the internal and external environment, and the emerging role of the immune system. Cell Tissue Res 2021; 384:589-605. [PMID: 33961125 PMCID: PMC8102665 DOI: 10.1007/s00441-021-03467-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 04/26/2021] [Indexed: 12/18/2022]
Abstract
Detection and discrimination of odorants by the olfactory system plays a pivotal role in animal survival. Olfactory-based behaviors must be adapted to an ever-changing environment. Part of these adaptations includes changes of odorant detection by olfactory sensory neurons localized in the olfactory epithelium. It is now well established that internal signals such as hormones, neurotransmitters, or paracrine signals directly affect the electric activity of olfactory neurons. Furthermore, recent data have shown that activity-dependent survival of olfactory neurons is important in the olfactory epithelium. Finally, as olfactory neurons are directly exposed to environmental toxicants and pathogens, the olfactory epithelium also interacts closely with the immune system leading to neuroimmune modulations. Here, we review how detection of odorants can be modulated in the vertebrate olfactory epithelium. We choose to focus on three cellular types of the olfactory epithelium (the olfactory sensory neuron, the sustentacular and microvillar cells) to present the diversity of modulation of the detection of odorant in the olfactory epithelium. We also present some of the growing literature on the importance of immune cells in the functioning of the olfactory epithelium, although their impact on odorant detection is only just beginning to be unravelled.
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Affiliation(s)
- Bertrand Bryche
- Université Paris-Saclay, INRAE, UVSQ, 78350, Jouy-en-Josas, VIM, France
| | - Christine Baly
- Université Paris Saclay, INRAE, UVSQ, BREED, 78350, Jouy-en-Josas, France
| | - Nicolas Meunier
- Université Paris-Saclay, INRAE, UVSQ, 78350, Jouy-en-Josas, VIM, France.
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38
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Glezer I, Bruni‐Cardoso A, Schechtman D, Malnic B. Viral infection and smell loss: The case of COVID-19. J Neurochem 2021; 157:930-943. [PMID: 32970861 PMCID: PMC7537178 DOI: 10.1111/jnc.15197] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022]
Abstract
Olfactory disorders have been increasingly reported in individuals infected with SARS-CoV-2, the virus causing the coronavirus disease 2019 (COVID-19). Losing the sense of smell has a strong impact on the quality of life, since it may lead to malnutrition, weight loss, food poisoning, depression, and exposure to dangerous chemicals. Individuals who suffer from anosmia (inability to smell) also cannot sense the flavor of food, which is a combination of taste and smell. Interestingly, infected individuals have reported sudden loss of smell with no congested nose, as is frequently observed in common colds or other upper respiratory tract infections. These observations suggest that SARS-CoV-2 infection leads to olfactory loss through a distinct mechanism, which is still unclear. This article provides an overview of olfactory loss and the recent findings relating to COVID-19. Possible mechanisms of SARS-CoV-2-induced olfactory loss are also discussed.
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Affiliation(s)
- Isaias Glezer
- Department of BiochemistryUNIFESPEscola Paulista de MedicinaUniversidade Federal de São PauloRua Tres de MaioSão PauloBrazil
| | | | | | - Bettina Malnic
- Department of BiochemistryUniversity of São PauloSão PauloBrazil
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Gupta K, Mohanty SK, Mittal A, Kalra S, Kumar S, Mishra T, Ahuja J, Sengupta D, Ahuja G. The Cellular basis of loss of smell in 2019-nCoV-infected individuals. Brief Bioinform 2021; 22:873-881. [PMID: 32810867 PMCID: PMC7462334 DOI: 10.1093/bib/bbaa168] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/10/2020] [Accepted: 07/05/2020] [Indexed: 12/28/2022] Open
Abstract
A prominent clinical symptom of 2019-novel coronavirus (nCoV) infection is hyposmia/anosmia (decrease or loss of sense of smell), along with general symptoms such as fatigue, shortness of breath, fever and cough. The identity of the cell lineages that underpin the infection-associated loss of olfaction could be critical for the clinical management of 2019-nCoV-infected individuals. Recent research has confirmed the role of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) as key host-specific cellular moieties responsible for the cellular entry of the virus. Accordingly, the ongoing medical examinations and the autopsy reports of the deceased individuals indicate that organs/tissues with high expression levels of ACE2, TMPRSS2 and other putative viral entry-associated genes are most vulnerable to the infection. We studied if anosmia in 2019-nCoV-infected individuals can be explained by the expression patterns associated with these host-specific moieties across the known olfactory epithelial cell types, identified from a recently published single-cell expression study. Our findings underscore selective expression of these viral entry-associated genes in a subset of sustentacular cells (SUSs), Bowman's gland cells (BGCs) and stem cells of the olfactory epithelium. Co-expression analysis of ACE2 and TMPRSS2 and protein-protein interaction among the host and viral proteins elected regulatory cytoskeleton protein-enriched SUSs as the most vulnerable cell type of the olfactory epithelium. Furthermore, expression, structural and docking analyses of ACE2 revealed the potential risk of olfactory dysfunction in four additional mammalian species, revealing an evolutionarily conserved infection susceptibility. In summary, our findings provide a plausible cellular basis for the loss of smell in 2019-nCoV-infected patients.
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Affiliation(s)
- Krishan Gupta
- Indraprastha Institute of Information Technology, Delhi
| | | | | | | | - Suvendu Kumar
- Indraprastha Institute of Information Technology, Delhi
| | - Tripti Mishra
- Indraprastha Institute of Information Technology, Delhi
| | - Jatin Ahuja
- Indraprastha Institute of Information Technology, Delhi
| | | | - Gaurav Ahuja
- Indraprastha Institute of Information Technology, Delhi
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40
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Meunier N, Briand L, Jacquin-Piques A, Brondel L, Pénicaud L. COVID 19-Induced Smell and Taste Impairments: Putative Impact on Physiology. Front Physiol 2021; 11:625110. [PMID: 33574768 PMCID: PMC7870487 DOI: 10.3389/fphys.2020.625110] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/31/2020] [Indexed: 12/18/2022] Open
Abstract
Smell and taste impairments are recognized as common symptoms in COVID 19 patients even in an asymptomatic phase. Indeed, depending on the country, in up to 85-90% of cases anosmia and dysgeusia are reported. We will review briefly the main mechanisms involved in the physiology of olfaction and taste focusing on receptors and transduction as well as the main neuroanatomical pathways. Then we will examine the current evidences, even if still fragmented and unsystematic, explaining the disturbances and mode of action of the virus at the level of the nasal and oral cavities. We will focus on its impact on the peripheral and central nervous system. Finally, considering the role of smell and taste in numerous physiological functions, especially in ingestive behavior, we will discuss the consequences on the physiology of the patients as well as management regarding food intake.
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Affiliation(s)
- Nicolas Meunier
- Université Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France
| | - Loïc Briand
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS UMR6265, INRAE UMR 1324, Université de Bourgogne Franche Comté, Dijon, France
| | - Agnès Jacquin-Piques
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS UMR6265, INRAE UMR 1324, Université de Bourgogne Franche Comté, Dijon, France
- Department of Clinical Neurophysiology, University Hospital, Dijon, France
| | - Laurent Brondel
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS UMR6265, INRAE UMR 1324, Université de Bourgogne Franche Comté, Dijon, France
| | - Luc Pénicaud
- STROMALab, Université de Toulouse, CNRS ERL 5311, Inserm U1031, Université Paul Sabatier (UPS), Toulouse, France
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41
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Weiss L, Manzini I, Hassenklöver T. Olfaction across the water-air interface in anuran amphibians. Cell Tissue Res 2021; 383:301-325. [PMID: 33496878 PMCID: PMC7873119 DOI: 10.1007/s00441-020-03377-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022]
Abstract
Extant anuran amphibians originate from an evolutionary intersection eventually leading to fully terrestrial tetrapods. In many ways, they have to deal with exposure to both terrestrial and aquatic environments: (i) phylogenetically, as derivatives of the first tetrapod group that conquered the terrestrial environment in evolution; (ii) ontogenetically, with a development that includes aquatic and terrestrial stages connected via metamorphic remodeling; and (iii) individually, with common changes in habitat during the life cycle. Our knowledge about the structural organization and function of the amphibian olfactory system and its relevance still lags behind findings on mammals. It is a formidable challenge to reveal underlying general principles of circuity-related, cellular, and molecular properties that are beneficial for an optimized sense of smell in water and air. Recent findings in structural organization coupled with behavioral observations could help to understand the importance of the sense of smell in this evolutionarily important animal group. We describe the structure of the peripheral olfactory organ, the olfactory bulb, and higher olfactory centers on a tissue, cellular, and molecular levels. Differences and similarities between the olfactory systems of anurans and other vertebrates are reviewed. Special emphasis lies on adaptations that are connected to the distinct demands of olfaction in water and air environment. These particular adaptations are discussed in light of evolutionary trends, ontogenetic development, and ecological demands.
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Affiliation(s)
- Lukas Weiss
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Ivan Manzini
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Thomas Hassenklöver
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany.
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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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Lankford CK, Laird JG, Inamdar SM, Baker SA. A Comparison of the Primary Sensory Neurons Used in Olfaction and Vision. Front Cell Neurosci 2020; 14:595523. [PMID: 33250719 PMCID: PMC7676898 DOI: 10.3389/fncel.2020.595523] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
Vision, hearing, smell, taste, and touch are the tools used to perceive and navigate the world. They enable us to obtain essential resources such as food and highly desired resources such as mates. Thanks to the investments in biomedical research the molecular unpinning’s of human sensation are rivaled only by our knowledge of sensation in the laboratory mouse. Humans rely heavily on vision whereas mice use smell as their dominant sense. Both modalities have many features in common, starting with signal detection by highly specialized primary sensory neurons—rod and cone photoreceptors (PR) for vision, and olfactory sensory neurons (OSN) for the smell. In this chapter, we provide an overview of how these two types of primary sensory neurons operate while highlighting the similarities and distinctions.
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Affiliation(s)
- Colten K Lankford
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Joseph G Laird
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Shivangi M Inamdar
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Sheila A Baker
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
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44
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Cooper KW, Brann DH, Farruggia MC, Bhutani S, Pellegrino R, Tsukahara T, Weinreb C, Joseph PV, Larson ED, Parma V, Albers MW, Barlow LA, Datta SR, Di Pizio A. COVID-19 and the Chemical Senses: Supporting Players Take Center Stage. Neuron 2020; 107:219-233. [PMID: 32640192 PMCID: PMC7328585 DOI: 10.1016/j.neuron.2020.06.032] [Citation(s) in RCA: 223] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 12/11/2022]
Abstract
The main neurological manifestation of COVID-19 is loss of smell or taste. The high incidence of smell loss without significant rhinorrhea or nasal congestion suggests that SARS-CoV-2 targets the chemical senses through mechanisms distinct from those used by endemic coronaviruses or other common cold-causing agents. Here we review recently developed hypotheses about how SARS-CoV-2 might alter the cells and circuits involved in chemosensory processing and thereby change perception. Given our limited understanding of SARS-CoV-2 pathogenesis, we propose future experiments to elucidate disease mechanisms and highlight the relevance of this ongoing work to understanding how the virus might alter brain function more broadly.
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Affiliation(s)
- Keiland W Cooper
- Interdepartmental Neuroscience Program, University of California Irvine, Irvine, CA, USA
| | - David H Brann
- Harvard Medical School Department of Neurobiology, Boston, MA, USA
| | | | - Surabhi Bhutani
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA, USA
| | - Robert Pellegrino
- Department of Food Science, Institute of Agriculture, University of Tennessee, Knoxville, TN, USA; Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | | | - Caleb Weinreb
- Harvard Medical School Department of Neurobiology, Boston, MA, USA
| | - Paule V Joseph
- Division of Intramural Research, National Institute of Nursing Research (NINR) National Institutes of Health, Bethesda, MD, USA; National Institute on Alcohol Abuse and Alcoholism (NIAAA) National Institutes of Health, Bethesda, MD, USA
| | - Eric D Larson
- Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA and the Rocky Mountain Taste and Smell Center, Aurora, CO, USA
| | - Valentina Parma
- Department of Psychology, Temple University, Philadelphia, PA, USA
| | - Mark W Albers
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Linda A Barlow
- Department of Cell and Developmental Biology, Graduate Program in Cell Biology, Stem Cells and Development and the Rocky Mountain Taste and Smell Center, University of Colorado, School Medicine, Anschutz Medical Campus, Aurora, CO, USA.
| | | | - Antonella Di Pizio
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany.
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45
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Soria-Gómez E. Special Issue "Olfaction: From Genes to Behavior". Genes (Basel) 2020; 11:genes11060654. [PMID: 32549403 PMCID: PMC7348778 DOI: 10.3390/genes11060654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/19/2022] Open
Affiliation(s)
- Edgar Soria-Gómez
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; or
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, 48940 Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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