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Dekeyser A, Huart C, Hummel T, Hox V. Olfactory Loss in Rhinosinusitis: Mechanisms of Loss and Recovery. Int J Mol Sci 2024; 25:4460. [PMID: 38674045 PMCID: PMC11050448 DOI: 10.3390/ijms25084460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Chronic rhinosinusitis (CRS) is a highly prevalent disease and up to 83% of CRS patients suffer from olfactory dysfunction (OD). Because OD is specifically seen in those CRS patients that present with a type 2 eosinophilic inflammation, it is believed that type 2 inflammatory mediators at the level of the olfactory epithelium are involved in the development of this olfactory loss. However, due to the difficulties in obtaining tissue from the olfactory epithelium, little is known about the true mechanisms of inflammatory OD. Thanks to the COVID-19 pandemic, interest in olfaction has been growing rapidly and several studies have been focusing on disease mechanisms of OD in inflammatory conditions. In this paper, we summarize the most recent data exploring the pathophysiological mechanisms underlying OD in CRS. We also review what is known about the potential capacity of olfactory recovery of the currently available treatments in those patients.
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Affiliation(s)
- Agnès Dekeyser
- Laboratory of Pneumology, ENT (Airways) and Dermatology (Skin) (LUNS), Institute of Experimental and Clinical Research (IREC), UCLouvain, 1200 Brussels, Belgium; (A.D.); (C.H.)
| | - Caroline Huart
- Laboratory of Pneumology, ENT (Airways) and Dermatology (Skin) (LUNS), Institute of Experimental and Clinical Research (IREC), UCLouvain, 1200 Brussels, Belgium; (A.D.); (C.H.)
- Department of Otorhinolaryngology, Head and Neck Surgery, Cliniques Universitaires Saint-Luc, 1200 Brussels, Belgium
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, University Hospital Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany;
| | - Valérie Hox
- Laboratory of Pneumology, ENT (Airways) and Dermatology (Skin) (LUNS), Institute of Experimental and Clinical Research (IREC), UCLouvain, 1200 Brussels, Belgium; (A.D.); (C.H.)
- Department of Otorhinolaryngology, Head and Neck Surgery, Cliniques Universitaires Saint-Luc, 1200 Brussels, Belgium
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Chen S, Wang S. The immune mechanism of the nasal epithelium in COVID-19-related olfactory dysfunction. Front Immunol 2023; 14:1045009. [PMID: 37529051 PMCID: PMC10387544 DOI: 10.3389/fimmu.2023.1045009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 06/29/2023] [Indexed: 08/03/2023] Open
Abstract
During the first waves of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, olfactory dysfunction (OD) was reported as a frequent clinical sign. The nasal epithelium is one of the front-line protections against viral infections, and the immune responses of the nasal mucosa may be associated with OD. Two mechanisms underlying OD occurrence in COVID-19 have been proposed: the infection of sustentacular cells and the inflammatory reaction of the nasal epithelium. The former triggers OD and the latter likely prolongs OD. These two alternative mechanisms may act in parallel; the infection of sustentacular cells is more important for OD occurrence because sustentacular cells are more likely to be the entry point of SARS-CoV-2 than olfactory neurons and more susceptible to early injury. Furthermore, sustentacular cells abundantly express transmembrane protease, serine 2 (TMPRSS2) and play a major role in the olfactory epithelium. OD occurrence in COVID-19 has revealed crucial roles of sustentacular cells. This review aims to elucidate how immune responses of the nasal epithelium contribute to COVID-19-related OD. Understanding the underlying immune mechanisms of the nasal epithelium in OD may aid in the development of improved medical treatments for COVID-19-related OD.
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Affiliation(s)
| | - Shufen Wang
- *Correspondence: Shunmei Chen, ; Shufen Wang,
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [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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Hummel T, Power Guerra N, Gunder N, Hähner A, Menzel S. Olfactory Function and Olfactory Disorders. Laryngorhinootologie 2023; 102:S67-S92. [PMID: 37130532 PMCID: PMC10184680 DOI: 10.1055/a-1957-3267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.
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Affiliation(s)
- T Hummel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - N Power Guerra
- Rudolf-Zenker-Institut für Experimentelle Chirurgie, Medizinische Universität Rostock, Rostock
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden
| | - A Hähner
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - S Menzel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
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Fahmy M, Whitcroft K. Psychophysical Testing in Chemosensory Disorders. CURRENT OTORHINOLARYNGOLOGY REPORTS 2022; 10:393-404. [PMID: 36120187 PMCID: PMC9468236 DOI: 10.1007/s40136-022-00429-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2022] [Indexed: 12/02/2022]
Abstract
Purpose of Review To provide an overview of psychophysical testing in olfaction and gustation. Recent Findings Subjective patient report correlates poorly with objective assessment of olfaction and gustation. It is therefore important that clinicians and researchers perform psychophysical testing during chemosensory assessment. There are several validated psychophysical tests of olfaction and gustation, with ongoing developments accelerated by the COVID-19 pandemic. These tests have been culturally and linguistically adapted globally. Screening tests have been developed with careful consideration to distinguish normosmics from those with olfactory dysfunction. Summary Validated chemosensory tools are available for use by the clinician to support screening, diagnosis, or monitoring. There are promising advances in self-assessment and screening that provide avenues for the development of a standardised pathway for identification and formal assessment of patients with smell and taste disorders.
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Affiliation(s)
- Miriam Fahmy
- ENT Department, Pinderfields Hospital, Mid Yorkshire Hospital NHS Trust, Wakefield, UK
- Wrexham, UK
| | - Katherine Whitcroft
- ENT Department, Pinderfields Hospital, Mid Yorkshire Hospital NHS Trust, Wakefield, UK
- UCL Ear Institute, London, UK
- Centre for Olfactory Research Applications, Institute of Philosophy, School of Advanced Study, London, UK
- Smell and Taste Clinic, Techniche Universität Dresden, Dresden, Germany
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Intranasal delivery of SARS-CoV-2 spike protein is sufficient to cause olfactory damage, inflammation and olfactory dysfunction in zebrafish. Brain Behav Immun 2022; 102:341-359. [PMID: 35307504 PMCID: PMC8929544 DOI: 10.1016/j.bbi.2022.03.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 03/03/2022] [Accepted: 03/12/2022] [Indexed: 02/07/2023] Open
Abstract
Anosmia, loss of smell, is a prevalent symptom of SARS-CoV-2 infection. Anosmia may be explained by several mechanisms driven by infection of non-neuronal cells and damage in the nasal epithelium rather than direct infection of olfactory sensory neurons (OSNs). Previously, we showed that viral proteins are sufficient to cause neuroimmune responses in the teleost olfactory organ (OO). We hypothesize that SARS-CoV-2 spike (S) protein is sufficient to cause olfactory damage and olfactory dysfunction. Using an adult zebrafish model, we report that intranasally delivered SARS-CoV-2 S RBD mostly binds to the non-sensory epithelium of the olfactory organ and causes severe olfactory histopathology characterized by loss of cilia, hemorrhages and edema. Electrophysiological recordings reveal impaired olfactory function to both food and bile odorants in animals treated intranasally with SARS-CoV-2 S RBD. However, no loss of behavioral preference for food was detected in SARS-CoV-2 S RBD treated fish. Single cell RNA-Seq of the adult zebrafish olfactory organ indicated widespread loss of olfactory receptor expression and inflammatory responses in sustentacular, endothelial, and myeloid cell clusters along with reduced numbers of Tregs. Combined, our results demonstrate that intranasal SARS-CoV-2 S RBD is sufficient to cause structural and functional damage to the zebrafish olfactory system. These findings may have implications for intranasally delivered vaccines against SARS-CoV-2.
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Patel ZM, Holbrook EH, Turner JH, Adappa ND, Albers MW, Altundag A, Appenzeller S, Costanzo RM, Croy I, Davis GE, Dehgani-Mobaraki P, Doty RL, Duffy VB, Goldstein BJ, Gudis DA, Haehner A, Higgins TS, Hopkins C, Huart C, Hummel T, Jitaroon K, Kern RC, Khanwalkar AR, Kobayashi M, Kondo K, Lane AP, Lechner M, Leopold DA, Levy JM, Marmura MJ, Mclelland L, Miwa T, Moberg PJ, Mueller CA, Nigwekar SU, O'Brien EK, Paunescu TG, Pellegrino R, Philpott C, Pinto JM, Reiter ER, Roalf DR, Rowan NR, Schlosser RJ, Schwob J, Seiden AM, Smith TL, Soler ZM, Sowerby L, Tan BK, Thamboo A, Wrobel B, Yan CH. International consensus statement on allergy and rhinology: Olfaction. Int Forum Allergy Rhinol 2022; 12:327-680. [PMID: 35373533 DOI: 10.1002/alr.22929] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/01/2021] [Accepted: 11/19/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O). METHODS Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus. RESULTS The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies. CONCLUSION This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.
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Affiliation(s)
- Zara M Patel
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Eric H Holbrook
- Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Justin H Turner
- Otolaryngology, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - Nithin D Adappa
- Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mark W Albers
- Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Aytug Altundag
- Otolaryngology, Biruni University School of Medicine, İstanbul, Turkey
| | - Simone Appenzeller
- Rheumatology, School of Medical Sciences, University of Campinas, São Paulo, Brazil
| | - Richard M Costanzo
- Physiology and Biophysics and Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Ilona Croy
- Psychology and Psychosomatic Medicine, TU Dresden, Dresden, Germany
| | - Greg E Davis
- Otolaryngology, Proliance Surgeons, Seattle and Puyallup, Washington, USA
| | - Puya Dehgani-Mobaraki
- Associazione Naso Sano, Umbria Regional Registry of Volunteer Activities, Corciano, Italy
| | - Richard L Doty
- Smell and Taste Center, Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Valerie B Duffy
- Allied Health Sciences, University of Connecticut, Storrs, Connecticut, USA
| | | | - David A Gudis
- Otolaryngology, Columbia University Irving Medical Center, New York, USA
| | - Antje Haehner
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | - Thomas S Higgins
- Otolaryngology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Claire Hopkins
- Otolaryngology, Guy's and St. Thomas' Hospitals, London Bridge Hospital, London, UK
| | - Caroline Huart
- Otorhinolaryngology, Cliniques universitaires Saint-Luc, Institute of Neuroscience, Université catholgique de Louvain, Brussels, Belgium
| | - Thomas Hummel
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | | | - Robert C Kern
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ashoke R Khanwalkar
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Masayoshi Kobayashi
- Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Mie, Japan
| | - Kenji Kondo
- Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Andrew P Lane
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Matt Lechner
- Otolaryngology, Barts Health and University College London, London, UK
| | - Donald A Leopold
- Otolaryngology, University of Vermont Medical Center, Burlington, Vermont, USA
| | - Joshua M Levy
- Otolaryngology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Michael J Marmura
- Neurology Thomas Jefferson University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lisha Mclelland
- Otolaryngology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Takaki Miwa
- Otolaryngology, Kanazawa Medical University, Ishikawa, Japan
| | - Paul J Moberg
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Sagar U Nigwekar
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Erin K O'Brien
- Otolaryngology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - Teodor G Paunescu
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Carl Philpott
- Otolaryngology, University of East Anglia, Norwich, UK
| | - Jayant M Pinto
- Otolaryngology, University of Chicago, Chicago, Illinois, USA
| | - Evan R Reiter
- Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - David R Roalf
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nicholas R Rowan
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rodney J Schlosser
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - James Schwob
- Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Allen M Seiden
- Otolaryngology, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Timothy L Smith
- Otolaryngology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Zachary M Soler
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - Leigh Sowerby
- Otolaryngology, University of Western Ontario, London, Ontario, Canada
| | - Bruce K Tan
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Andrew Thamboo
- Otolaryngology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bozena Wrobel
- Otolaryngology, Keck School of Medicine, USC, Los Angeles, California, USA
| | - Carol H Yan
- Otolaryngology, School of Medicine, UCSD, La Jolla, California, USA
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Lin YT, Yeh TH. Studies on Clinical Features, Mechanisms, and Management of Olfactory Dysfunction Secondary to Chronic Rhinosinusitis. FRONTIERS IN ALLERGY 2022; 3:835151. [PMID: 35386650 PMCID: PMC8974686 DOI: 10.3389/falgy.2022.835151] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/01/2022] [Indexed: 12/14/2022] Open
Abstract
Chronic rhinosinusitis (CRS) is one of the most common causes of inflammation of the olfactory system, warranting investigation of the link between chronic inflammation and the loss of olfactory function. Type 2 inflammation is closely related to the clinical features and disease mechanisms of olfactory dysfunction secondary to CRS. Patients with eosinophilic CRS, aspirin-exacerbated respiratory disease, and central compartment atopic disease report increased olfactory dysfunction. Increased levels of interleukin-(IL-)2, IL-5, IL-6, IL-10, and IL-13 in the mucus from the olfactory slit have been reported to be associated with reduced olfactory test scores. The influence of several cytokines and signaling transduction pathways, including tumor necrosis factor-α, nuclear factor-κB, and c-Jun N-terminal kinases, on olfactory signal processing and neurogenesis has been demonstrated. Corticosteroids are the mainstay treatment for olfactory dysfunction secondary to CRS. Successful olfaction recovery was recently demonstrated in clinical trials of biotherapeutics, including omalizumab and dupilumab, although the treatment effect may diminish gradually after stopping the use of the medications. Future studies are required to relate the complex mechanisms underlying chronic inflammation in CRS to dysfunction of the olfactory system.
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Affiliation(s)
- Yi-Tsen Lin
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Te-Huei Yeh
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
- College of Medicine, National Taiwan University, Taipei, Taiwan
- *Correspondence: Te-Huei Yeh
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Lakshmanan HG, Miller E, White-Canale A, McCluskey LP. Immune responses in the injured olfactory and gustatory systems: a role in olfactory receptor neuron and taste bud regeneration? Chem Senses 2022; 47:bjac024. [PMID: 36152297 PMCID: PMC9508897 DOI: 10.1093/chemse/bjac024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Sensory cells that specialize in transducing olfactory and gustatory stimuli are renewed throughout life and can regenerate after injury unlike their counterparts in the mammalian retina and auditory epithelium. This uncommon capacity for regeneration offers an opportunity to understand mechanisms that promote the recovery of sensory function after taste and smell loss. Immune responses appear to influence degeneration and later regeneration of olfactory sensory neurons and taste receptor cells. Here we review surgical, chemical, and inflammatory injury models and evidence that immune responses promote or deter chemosensory cell regeneration. Macrophage and neutrophil responses to chemosensory receptor injury have been the most widely studied without consensus on their net effects on regeneration. We discuss possible technical and biological reasons for the discrepancy, such as the difference between peripheral and central structures, and suggest directions for progress in understanding immune regulation of chemosensory regeneration. Our mechanistic understanding of immune-chemosensory cell interactions must be expanded before therapies can be developed for recovering the sensation of taste and smell after head injury from traumatic nerve damage and infection. Chemosensory loss leads to decreased quality of life, depression, nutritional challenges, and exposure to environmental dangers highlighting the need for further studies in this area.
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Affiliation(s)
- Hari G Lakshmanan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Elayna Miller
- Department of Medical Illustration, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - AnnElizabeth White-Canale
- Department of Medical Illustration, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Lynnette P McCluskey
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
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10
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Chitinase-Like Protein Ym2 (Chil4) Regulates Regeneration of the Olfactory Epithelium via Interaction with Inflammation. J Neurosci 2021; 41:5620-5637. [PMID: 34016714 DOI: 10.1523/jneurosci.1601-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 04/14/2021] [Accepted: 05/06/2021] [Indexed: 11/21/2022] Open
Abstract
The adult olfactory epithelium (OE) regenerates sensory neurons and nonsensory supporting cells from resident stem cells after injury. How supporting cells contribute to OE regeneration remains largely unknown. In this study, we elucidated a novel role of Ym2 (also known as Chil4 or Chi3l4), a chitinase-like protein expressed in supporting cells, in regulating regeneration of the injured OE in vivo in both male and female mice and cell proliferation/differentiation in OE colonies in vitro We found that Ym2 expression was enhanced in supporting cells after OE injury. Genetic knockdown of Ym2 in supporting cells attenuated recovery of the injured OE, while Ym2 overexpression by lentiviral infection accelerated OE regeneration. Similarly, Ym2 bidirectionally regulated cell proliferation and differentiation in OE colonies. Furthermore, anti-inflammatory treatment reduced Ym2 expression and delayed OE regeneration in vivo and cell proliferation/differentiation in vitro, which were counteracted by Ym2 overexpression. Collectively, this study revealed a novel role of Ym2 in OE regeneration and cell proliferation/differentiation of OE colonies via interaction with inflammatory responses, providing new clues to the function of supporting cells in these processes.SIGNIFICANCE STATEMENT The mammalian olfactory epithelium (OE) is a unique neural tissue that regenerates sensory neurons and nonsensory supporting cells throughout life and postinjury. How supporting cells contribute to this process is not entirely understood. Here we report that OE injury causes upregulation of a chitinase-like protein, Ym2, in supporting cells, which facilitates OE regeneration. Moreover, anti-inflammatory treatment reduces Ym2 expression and delays OE regeneration, which are counteracted by Ym2 overexpression. This study reveals an important role of supporting cells in OE regeneration and provides a critical link between Ym2 and inflammation in this process.
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11
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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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12
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Lemons K, Fu Z, Ogura T, Lin W. TRPM5-expressing Microvillous Cells Regulate Region-specific Cell Proliferation and Apoptosis During Chemical Exposure. Neuroscience 2020; 434:171-190. [PMID: 32224228 DOI: 10.1016/j.neuroscience.2020.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/23/2022]
Abstract
The mammalian main olfactory epithelium (MOE) is exposed to a wide spectrum of external chemicals during respiration and relies on adaptive plasticity to maintain its structural and functional integrity. We previously reported that the chemo-responsive and cholinergic transient receptor potential channel M5 (TRPM5)-expressing-microvillous cells (MCs) in the MOE are required for maintaining odor-evoked electrophysiological responses and olfactory-guided behavior during two-week exposure to an inhaled chemical mixture. Here, we investigated the underlying factors by assessing the potential modulatory effects of TRPM5-MCs on MOE morphology and cell proliferation and apoptosis, which are important for MOE maintenance. In the posterior MOE of TRPM5-GFP mice, we found that two-week chemical exposure induced a significant increase in Ki67-expressing proliferating basal stem cells without a significant reduction in the thickness of the whole epithelium or mature olfactory sensory neuron (OSN) layer. This adaptive increase in stem cell proliferation was missing in chemical-exposed transcription factor Skn-1a knockout (Skn-1a-/-) mice lacking TRPM5-MCs. In addition, a greater number of isolated OSNs from chemical-exposed Skn-1a-/- mice displayed unhealthily high levels of resting intracellular Ca2+. Intriguingly, in the anterior MOE where we found a higher density of TRPM5-MCs, chemical-exposed TRPM5-GFP mice exhibited a time-dependent increase in apoptosis and a loss of mature OSNs without a significant increase in proliferation or neurogenesis to compensate for OSN loss. Together, our data suggest that TRPM5-MC-dependent region-specific upregulation of cell proliferation in the majority of the MOE during chemical exposure contributes to the adaptive maintenance of OSNs and olfactory function.
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Affiliation(s)
- Kayla Lemons
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Ziying Fu
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Tatsuya Ogura
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Weihong Lin
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
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Wu D, Bleier BS, Wei Y. Temporary olfactory improvement in chronic rhinosinusitis with nasal polyps after treatment. Eur Arch Otorhinolaryngol 2018; 275:2193-2202. [DOI: 10.1007/s00405-018-5066-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/13/2018] [Indexed: 01/04/2023]
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14
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Hauser LJ, Chandra RK, Li P, Turner JH. Role of tissue eosinophils in chronic rhinosinusitis-associated olfactory loss. Int Forum Allergy Rhinol 2017; 7:957-962. [PMID: 28742240 DOI: 10.1002/alr.21994] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/05/2017] [Accepted: 06/28/2017] [Indexed: 01/05/2023]
Abstract
BACKGROUND Olfactory dysfunction is 1 of the hallmark symptoms of chronic rhinosinusitis (CRS). Eosinophilic inflammation has been implicated as a potential causative factor. However, prior studies have been limited by retrospective study designs, concomitant use of systemic corticosteroids, and other confounding factors. METHODS CRS and healthy non-CRS control subjects undergoing endoscopic sinus or skull-base surgery were prospectively enrolled and completed olfactory testing utilizing the 40-item Smell Identification Test (SIT) immediately prior to surgery. Histopathological evaluation of tissue excised from the ethmoid bulla was performed by a pathologist in a blinded fashion. Disease severity and patient-reported outcomes were measured via the Lund-Mackay computed tomography (CT) grading system and 22-item Sino-Nasal Outcome Test (SNOT-22), respectively. The associations between olfactory function, tissue eosinophilia, and disease severity were analyzed using Spearman rank order correlation and multiple linear regression. RESULTS Twenty-seven (27) subjects with CRS without nasal polyps (CRSsNP), 32 subjects with CRS with nasal polyps (CRSwNP), and 10 healthy non-CRS controls were enrolled. CRSwNP was associated with higher mean tissue eosinophil counts (71.6 vs 28.1 eosinophils/high-power field [HPF], p < 0.05) and lower age/sex-adjusted SIT scores (-17.4 vs -6.2, p < 0.001) when compared to CRSsNP. SIT scores were strongly negatively correlated with tissue eosinophil counts in CRSwNP (r = -0.60, p = 0.0003), but not CRSsNP (r = 0.16, p = 0.42). The correlation between olfactory function and tissue eosinophilia in CRSwNP persisted after adjusting for disease severity. CONCLUSION Tissue eosinophilia is associated with olfactory loss in CRSwNP, independent of disease severity. These results suggest a possible role for eosinophils or eosinophil-associated cytokines in CRS-associated olfactory loss.
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Affiliation(s)
- Leah J Hauser
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University School of Medicine, Nashville, TN
| | - Rakesh K Chandra
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University School of Medicine, Nashville, TN
| | - Ping Li
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University School of Medicine, Nashville, TN
| | - Justin H Turner
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University School of Medicine, Nashville, TN
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Han P, Whitcroft KL, Fischer J, Gerber J, Cuevas M, Andrews P, Hummel T. Olfactory brain gray matter volume reduction in patients with chronic rhinosinusitis. Int Forum Allergy Rhinol 2017; 7:551-556. [DOI: 10.1002/alr.21922] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 01/19/2023]
Affiliation(s)
- Pengfei Han
- Smell & Taste Clinic, Department of Otorhinolaryngology; Technische Universität Dresden; Dresden Germany
- Department of Neuropediatrics; University Hospital Carl Gustav Carus; Dresden Germany
| | - Katherine L. Whitcroft
- Smell & Taste Clinic, Department of Otorhinolaryngology; Technische Universität Dresden; Dresden Germany
- UCL Ear Institute; London UK
| | - Jessica Fischer
- Smell & Taste Clinic, Department of Otorhinolaryngology; Technische Universität Dresden; Dresden Germany
| | - Johannes Gerber
- Department of Neuroradiology; Technische Universität Dresden; Dresden Germany
| | - Mandy Cuevas
- Smell & Taste Clinic, Department of Otorhinolaryngology; Technische Universität Dresden; Dresden Germany
| | | | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology; Technische Universität Dresden; Dresden Germany
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Imamura F, Hasegawa-Ishii S. Environmental Toxicants-Induced Immune Responses in the Olfactory Mucosa. Front Immunol 2016; 7:475. [PMID: 27867383 PMCID: PMC5095454 DOI: 10.3389/fimmu.2016.00475] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/19/2016] [Indexed: 01/02/2023] Open
Abstract
Olfactory sensory neurons (OSNs) are the receptor cells for the sense of smell. Although cell bodies are located in the olfactory mucosa (OM) of the nasal cavity, OSN axons directly project to the olfactory bulb (OB) that is a component of the central nervous system (CNS). Because of this direct and short connection from this peripheral tissue to the CNS, the olfactory system has attracted attention as a port-of-entry for environmental toxicants that may cause neurological dysfunction. Selected viruses can enter the OB via the OM and directly affect the CNS. On the other hand, environmental toxicants may induce inflammatory responses in the OM, including infiltration of immune cells and production of inflammatory cytokines. In addition, these inflammatory responses cause the loss of OSNs that are then replaced with newly generated OSNs that re-connect to the OB after inflammation has subsided. It is now known that immune cells and cytokines in the OM play important roles in both degeneration and regeneration of OSNs. Thus, the olfactory system is a unique neuroimmune interface where interaction between nervous and immune systems in the periphery significantly affects the structure, neuronal circuitry, and immunological status of the CNS. The mechanisms by which immune cells regulate OSN loss and the generation of new OSNs are, however, largely unknown. To help develop a better understanding of the mechanisms involved, we have provided a review of key research that has investigated how the immune response in the OM affects the pathophysiology of OSNs.
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Affiliation(s)
- Fumiaki Imamura
- Department of Pharmacology, Penn State College of Medicine , Hershey, PA , USA
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17
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Sousa Garcia D, Chen M, Smith AK, Lazarini PR, Lane AP. Role of the type I tumor necrosis factor receptor in inflammation-associated olfactory dysfunction. Int Forum Allergy Rhinol 2016; 7:160-168. [PMID: 27671548 DOI: 10.1002/alr.21855] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/18/2016] [Accepted: 08/28/2016] [Indexed: 11/11/2022]
Abstract
BACKGROUND To understand mechanisms of human olfactory dysfunction in chronic rhinosinusitis, an inducible olfactory inflammation (IOI) model has been utilized to chronically express inflammatory cytokines locally, resulting in neuronal loss, diminished odorant responses, and repressed olfactory regeneration. Knockout of the minor tumor necrosis factor α receptor 2 (TNFR2) was previously shown to partially rescue these olfactory changes. The purpose of current study was to investigate the role of the major TNF receptor, TNFR1, in chronic olfactory inflammation. METHODS Two experimental groups of mice were studied: TNFR1 knockout in IOI background and TNFR1 knockout with allergen-induced inflammation. Olfactory function was assayed by electro-olfactogram (EOG), and olfactory tissue was processed for histology and immunohistochemical staining. RESULTS TNF-α was dramatically induced in IOI-TNFR1 knockout mice, but the olfactory epithelium did not show inflammation. EOG responses were normal after either 2 or 8 weeks of TNF-α expression. Ovalbumin-sensitized TNFR1 knockout mice developed markedly diminished eosinophilic inflammatory infiltration. CONCLUSION Genetic deletion of TNFR1 completely blocks TNF-α-induced inflammation and reduces allergen-induced inflammation. Preserved EOG responses suggest a TNFR1-dependent mechanism of TNF-α-induced olfactory neuron dysfunction.
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Affiliation(s)
- Davi Sousa Garcia
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Otolaryngology, Santa Casa de Sao Paulo School of Medical Sciences, Sao Paulo, Brazil
| | - Mengfei Chen
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Amy K Smith
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Paulo Roberto Lazarini
- Department of Otolaryngology, Santa Casa de Sao Paulo School of Medical Sciences, Sao Paulo, Brazil
| | - Andrew P Lane
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
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18
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Whitcroft KL, Cuevas M, Haehner A, Hummel T. Patterns of olfactory impairment reflect underlying disease etiology. Laryngoscope 2016; 127:291-295. [PMID: 27556251 DOI: 10.1002/lary.26229] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 06/20/2016] [Accepted: 07/12/2016] [Indexed: 01/28/2023]
Abstract
OBJECTIVE We aimed to determine whether the pattern of olfactory impairment seen in psychophysical testing reflects underlying disease etiology. STUDY DESIGN Retrospective cohort. METHODS We performed a retrospective analysis of 1,226 patients from our tertiary referral center. Only hyposmic patients with the following conditions were included: postinfectious hyposmia, posttraumatic hyposmia, hyposmia secondary to sinonasal disease, and hyposmia secondary to Parkinson disease. Patients with anosmia were excluded. RESULTS Using a repeated measures analysis of variance (within subject factor "test": threshold [T], discrimination [D], identification [I]; between subject factor: "etiology") with posthoc Bonferroni corrected t tests, we found significant interaction between the factors "test" and "etiology" (F6,2444 = 8.46, P < 0.001), indicating that different causes of hyposmia produce different patterns of olfactory loss with respect to the individual subtests T, D, and I . Specifically, patients with Parkinson disease performed relatively well in odor threshold testing, but poorly in odor identification and discrimination compared with the other etiology groups. Conversely, patients with sinonasal disease performed well in odor identification and discrimination but poorly in odor threshold. Patients with postinfectious and posttraumatic hyposmia performed relatively well in both thresholds and discrimination but poorly in identification. However, patients with posttraumatic hyposmia had globally reduced scores compared with the other groups. CONCLUSION This is the first study to comprehensively show that patterns of olfactory impairment reflect underlying disease etiology. We suggest that multicomponent olfactory testing should be performed, especially if there is diagnostic uncertainty. However, to clearly separate different patterns of olfactory loss to the various causes at an individual level, more work is needed. LEVEL OF EVIDENCE 4. Laryngoscope, 2016 127:291-295, 2017.
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Affiliation(s)
- Katherine L Whitcroft
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Mandy Cuevas
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Antje Haehner
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
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Seo Y, Kim HS, Shin Y, Kang I, Choi SW, Yu KR, Seo KW, Kang KS. Excessive microglial activation aggravates olfactory dysfunction by impeding the survival of newborn neurons in the olfactory bulb of Niemann-Pick disease type C1 mice. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2193-203. [PMID: 25132229 DOI: 10.1016/j.bbadis.2014.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 12/26/2022]
Abstract
Progressive olfactory impairment is one of the earliest markers of neurodegeneration. However, the underlying mechanism for this dysfunction remains unclear. The present study investigated the possible role of microgliosis in olfactory deficits using a mouse model of Niemann-Pick disease type C1 (NPC1), which is an incurable neurodegenerative disorder with disrupted lipid trafficking. At 7weeks of age, NPC1 mutants showed a distinct olfactory impairment in an olfactory test compared with age-matched wild-type controls (WT). The marked loss of olfactory sensory neurons within the NPC1 affected olfactory bulb (NPC1-OB) suggests that NPC1 dysfunction impairs olfactory structure. Furthermore, the pool of neuroblasts in the OB was diminished in NPC1 mice despite the intact proliferative capacity of neural stem/progenitor cells in the subventricular zone. Instead, pro-inflammatory proliferating microglia accumulated extensively in the NPC1-OB as the disease progressed. To evaluate the impact of abnormal microglial activation on olfaction in NPC1 mice, a microglial inhibition study was performed using the anti-inflammatory agent Cyclosporin A (CsA). Importantly, long-term CsA treatment in NPC1 mice reduced reactive microgliosis, restored the survival of newly generated neurons in the OB and improved overall performance on the olfactory test. Therefore, our study highlights the possible role of microglia in the regulation of neuronal turnover in the OB and provides insight into the possible therapeutic applications of microglial inhibition in the attenuation or reversal of olfactory impairment.
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Affiliation(s)
- Yoojin Seo
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea
| | - Hyung-Sik Kim
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea; Institute for Stem Cell and Regenerative Medicine at Kangstem Biotech, Biotechnology Incubating Center, Seoul National University, Seoul 151-742, South Korea
| | - Yooyoung Shin
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea
| | - Insung Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea
| | - Soon Won Choi
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea
| | - Kyung-Rok Yu
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea
| | - Kwang-Won Seo
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea; Institute for Stem Cell and Regenerative Medicine at Kangstem Biotech, Biotechnology Incubating Center, Seoul National University, Seoul 151-742, South Korea.
| | - Kyung-Sun Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea.
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Jacobs J. Editorial: allergy and immunology. Int Forum Allergy Rhinol 2014; 3:689-90. [PMID: 24078290 DOI: 10.1002/alr.21225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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