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Kikuta S, Nagayama S, Hasegawa-Ishii S. Structures and functions of the normal and injured human olfactory epithelium. Front Neural Circuits 2024; 18:1406218. [PMID: 38903957 PMCID: PMC11188711 DOI: 10.3389/fncir.2024.1406218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 05/20/2024] [Indexed: 06/22/2024] Open
Abstract
The olfactory epithelium (OE) is directly exposed to environmental agents entering the nasal cavity, leaving OSNs prone to injury and degeneration. The causes of olfactory dysfunction are diverse and include head trauma, neurodegenerative diseases, and aging, but the main causes are chronic rhinosinusitis (CRS) and viral infections. In CRS and viral infections, reduced airflow due to local inflammation, inflammatory cytokine production, release of degranulated proteins from eosinophils, and cell injury lead to decreased olfactory function. It is well known that injury-induced loss of mature OSNs in the adult OE causes massive regeneration of new OSNs within a few months through the proliferation and differentiation of progenitor basal cells that are subsequently incorporated into olfactory neural circuits. Although normal olfactory function returns after injury in most cases, prolonged olfactory impairment and lack of improvement in olfactory function in some cases poses a major clinical problem. Persistent inflammation or severe injury in the OE results in morphological changes in the OE and respiratory epithelium and decreases the number of mature OSNs, resulting in irreversible loss of olfactory function. In this review, we discuss the histological structure and distribution of the human OE, and the pathogenesis of olfactory dysfunction associated with CRS and viral infection.
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Affiliation(s)
- Shu Kikuta
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Nihon University, Tokyo, Japan
| | - Shin Nagayama
- Department of Neurobiology and Anatomy, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, United States
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Dietz A, Senf K, Neuhaus EM. ACKR3 in olfactory glia cells shapes the immune defense of the olfactory mucosa. Glia 2024; 72:1183-1200. [PMID: 38477581 DOI: 10.1002/glia.24527] [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: 01/09/2024] [Revised: 03/04/2024] [Accepted: 03/06/2024] [Indexed: 03/14/2024]
Abstract
Barrier-forming olfactory glia cells, termed sustentacular cells, play important roles for immune defense of the olfactory mucosa, for example as entry sites for SARS-CoV-2 and subsequent development of inflammation-induced smell loss. Here we demonstrate that sustentacular cells express ACKR3, a chemokine receptor that functions both as a scavenger of the chemokine CXCL12 and as an activator of alternative signaling pathways. Differential gene expression analysis of bulk RNA sequencing data obtained from WT and ACKR3 conditional knockout mice revealed upregulation of genes involved in immune defense. To map the regulated genes to the different cell types of the olfactory mucosa, we employed biocomputational methods utilizing a single-cell reference atlas. Transcriptome analysis, PCR and immunofluorescence identified up-regulation of NF-κB-related genes, known to amplify inflammatory signaling and to facilitate leukocyte transmigration, in the gliogenic lineage. Accordingly, we found a marked increase in leukocyte-expressed genes and confirmed leukocyte infiltration into the olfactory mucosa. In addition, lack of ACKR3 led to enhanced expression and secretion of early mediators of immune defense by Bowman's glands. As a result, the number of apoptotic cells in the epithelium was decreased. In conclusion, our research underlines the importance of sustentacular cells in immune defense of the olfactory mucosa. Moreover, it identifies ACKR3, a druggable G protein-coupled receptor, as a promising target for modulation of inflammation-associated anosmia.
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Affiliation(s)
- André Dietz
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Katja Senf
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Eva M Neuhaus
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
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Shaker MS. Chronic sinusitis in 2023: Promises of medical research realized and those yet to come. Ann Allergy Asthma Immunol 2023; 131:285-286. [PMID: 37661166 DOI: 10.1016/j.anai.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 09/05/2023]
Affiliation(s)
- Marcus S Shaker
- Section of Allergy and Immunology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; Dartmouth Geisel School of Medicine, Hanover, New Hampshire.
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Orozco FR, Lin M, Hur K. Cannabis Use and Sinonasal Symptoms in US Adults. JAMA Otolaryngol Head Neck Surg 2022; 148:854-861. [PMID: 35900733 PMCID: PMC9335247 DOI: 10.1001/jamaoto.2022.2001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Cannabis is the most commonly used illicit substance in the US and worldwide. Understanding the association between cannabis use and sinonasal symptoms may help clinicians and patients better understand the symptomatology associated with cannabis use. Objective To assess the association between frequency of cannabis use and presence of sinonasal symptoms in a nationally representative sample of US adults. Design, Setting, and Participants This population-based, retrospective cross-sectional study included adults aged 20 to 69 years who had completed data on sinonasal symptoms and substance use for the 2013 to 2014 National Health and Nutrition Examination Survey. The data were analyzed in February 2022. Exposures Cannabis use frequency. Main Outcomes and Measures Presence of sinonasal symptoms, demographic information, and medical history were obtained from National Health and Nutrition Examination Survey questionnaires. Presence of any sinonasal symptoms was defined as responding yes to any of a series of questions assessing rhinologic symptoms. Regular cannabis users were defined as using cannabis 15 or more times within the last 30 days. Nonregular users were defined as using cannabis fewer than 15 times within the last 30 days. Multivariable models were used to examine the association between frequency of cannabis use and presence of sinonasal symptoms while adjusting for demographic characteristics and medical comorbidities. Results The study included 2269 adults with a mean (SD) age of 36.5 (12.4) years (1207 women [53.2%]; 330 Asian [14.5%], 739 Black [32.6%], 461 Hispanic [20.3%], and 656 White [28.9%] individuals). The prevalence of sinonasal symptoms among regular cannabis users (45.0%; 95% Cl, 38.9%-51.1%) was lower than the prevalence among never users (64.5%; 95% Cl, 58.3%-68.8%). Compared with adults who had never used cannabis, regular cannabis users were less likely to have sinonasal symptoms (odds ratio, 0.22, 95% CI, 0.10-0.50). Current tobacco smokers were more likely to have sinonasal symptoms (odds ratio, 1.96; 95% CI, 1.17-3.28). The most common sinonasal symptoms reported were nasal congestion (62.8%; 95% Cl, 60.2%-65.4%) and change in smell (17.8%; 95% Cl, 15.2%-20.9%). Conclusions and Relevance This cross-sectional study found that the prevalence of sinonasal symptoms was lower among regular cannabis users. Further research is needed to elucidate the mechanisms underlying the association between cannabis use and sinonasal symptoms.
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Affiliation(s)
| | - Matthew Lin
- Keck School of Medicine of the University of Southern California, Los Angeles
| | - Kevin Hur
- Caruso Department of Otolaryngology-Head & Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles
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LaFever BJ, Kawasawa YI, Ito A, Imamura F. Pathological consequences of chronic olfactory inflammation on neurite morphology of olfactory bulb projection neurons. Brain Behav Immun Health 2022; 21:100451. [PMID: 35360408 PMCID: PMC8960895 DOI: 10.1016/j.bbih.2022.100451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/10/2022] [Accepted: 03/12/2022] [Indexed: 11/22/2022] Open
Abstract
Chronic olfactory inflammation (COI) in conditions such as chronic rhinosinusitis significantly impairs the functional and anatomical components of the olfactory system. COI induced by intranasal administration of lipopolysaccharide (LPS) results in atrophy, gliosis, and pro-inflammatory cytokine production in the olfactory bulb (OB). Although chronic rhinosinusitis patients have smaller OBs, the consequences of olfactory inflammation on OB neurons are largely unknown. In this study, we investigated the neurological consequences of COI on OB projection neurons, mitral cells (MCs) and tufted cells (TCs). To induce COI, we performed unilateral intranasal administration of LPS to mice for 4 and 10 weeks. Effects of COI on the OB were examined using RNA-sequencing approaches and immunohistochemical analyses. We found that repeated LPS administration upregulated immune-related biological pathways in the OB after 4 weeks. We also determined that the length of TC lateral dendrites in the OB significantly decreased after 10 weeks of COI. The axon initial segment of TCs decreased in number and in length after 10 weeks of COI. The lateral dendrites and axon initial segments of MCs, however, were largely unaffected. In addition, dendritic arborization and AIS reconstruction both took place following a 10-week recovery period. Our findings suggest that olfactory inflammation specifically affects TCs and their integrated circuitry, whereas MCs are potentially protected from this condition. This data demonstrates unique characteristics of the OBs ability to undergo neuroplastic changes in response to stress. Early-stage chronic olfactory inflammation activates the interferon-γ-driven inflammatory pathways in the olfactory bulb. Tufted cells undergo neurite dysregulation in response to chronic olfactory inflammation. Mitral cells and interneurons in the external plexiform layer are largely unaffected by chronic olfactory inflammation. Tufted cells experience complete recovery from neurite dysregulation following a period of ceased inflammation
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Affiliation(s)
- Brandon J. LaFever
- Department of Pharmacology, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
| | - Yuka Imamura Kawasawa
- Department of Pharmacology, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
- Institute for Personalized Medicine, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
| | - Ayako Ito
- Department of Pharmacology, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
| | - Fumiaki Imamura
- Department of Pharmacology, Penn State College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
- Corresponding author. Department of Pharmacology, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA.
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Alotaibi N, Alsheikh H, Zahlan A, AlMana F, Abduljawwad S, Omar O, Alshehri A, Mohammed A, Alsaleh S. Translation and validation of the “Smell Diskettes” Olfaction Test into Arabic. RHINOLOGY ONLINE 2022. [DOI: 10.4193/rhinol/21.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Objective: This study aims to translate and validate the 'Smell Diskettes' screening tool from English into Arabic. The significance of this study stems from the lack of reliable and rapid olfaction screening tests available to Arabic speaking patients and healthcare practitioners. Methods: This is a prospective cohort, multi-center study. A forward-backward translation of the olfaction screening test was done to translate the text into Arabic. Data was collected from two groups: a control group (n=125) of which 84 percent were females (n=105) and a mean age of 22.4 of subjectively normosmic individuals from Alfaisal University and a patients group (n=82) of which 35.4 percent females (n = 29) with a mean age of 38.2, all of whom were diagnosed with olfactory disturbances related to rhinological pathologies, from King Abdulaziz University Hospital (KAUH) in Riyadh, Saudi Arabia. One of the limitations we faced due to convenience sampling and COVID-19 pandemic restrictions was the inability to perform a “test-retest” on study subjects. Results: The study included 207 subjects, out of whom 82 (40 percent) were patients from the rhinology clinic at King Abdulaziz University Hospital (KAUH) and 125 (60 percent) were recruited as controls from Alfaisal University. The average olfaction scores for the control group and the patients’ group were 7/8 and 5/8, respectively. Conclusion: This study has determined that the Arabic-language version is a valid and useful instrument used in clinical practice and for research purposes. The development of this tool will allow more patients in Arabic-speaking countries to be screened for olfactory disturbances.
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Jang SS, Choi JS, Kim JH, Kim N, Ference EH. Discordance Between Subjective and Objective Measures of Smell and Taste in US Adults. Otolaryngol Head Neck Surg 2021; 166:572-579. [PMID: 34154442 DOI: 10.1177/01945998211018386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Examine the rates and factors associated with under- and overreporting of subjective changes in smell or taste as compared with objective measures. STUDY DESIGN Cross-sectional analysis. SETTING National Health and Nutrition Examination Survey (2013-2014). METHODS We examined participants ≥40 years old who completed subjective questionnaires (smell, n = 3510; taste, n = 3089), validated objective 8-odor pocket smell tests, and NaCl/quinine taste tests. Over- and underreporting was determined by the difference in subjective and objective results. Univariate and multivariate logistic regression analyses incorporated sampling weights. RESULTS A majority of participants correctly classified impairment: smell (73.7%; 95% CI, 71.2%-76.1%) and taste (78.3%; 95% CI, 75.6%-80.7%). Age ≥65 years (odds ratio, 2.23; P = .001) was associated with underreporting impairment, and persistent cold symptoms (odds ratio, 2.15; P = .001) were associated with overreporting smell impairment. Smoke, onion, and natural gas scents were incorrectly identified more frequently by individuals aged ≥65 years after Bonferroni correction. No factors were associated with under- and overreporting taste impairment. CONCLUSION Although the concordance rate between subjective and objective assessment of smell and taste impairment remains high, we found that older age was associated with incorrect report of impairment. This suggests that the subjective perception of smell varies across demographical and clinical factors, and it is important to not overlook such factors in clinical practice. Potentially using a simplified odor assessment regularly in the clinical setting may aid in early detection and intervention.
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Affiliation(s)
- Sophie S Jang
- Royal College of Surgeons in Ireland, Dublin, Republic of Ireland
| | - Janet S Choi
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - James H Kim
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Natalie Kim
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Elisabeth H Ference
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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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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Haxel BR. Recovery of olfaction after sinus surgery for chronic rhinosinusitis: A review. Laryngoscope 2019; 129:1053-1059. [DOI: 10.1002/lary.27764] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Boris R. Haxel
- Department of Otolaryngology, Head and Neck SurgeryAMEOS Klinikum Haldensleben Haldensleben Germany
- Department of Otolaryngology, Head and Neck SurgeryUniversity Medical Center of the Johannes Gutenberg University Mainz Germany
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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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