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Forni PE, Yu CR. Two decades on: Special issue on olfaction celebrating Axel and Buck's Nobel Prize. Genesis 2024; 62:e23613. [PMID: 39054874 DOI: 10.1002/dvg.23613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 06/27/2024] [Accepted: 06/29/2024] [Indexed: 07/27/2024]
Affiliation(s)
- Paolo E Forni
- Department of Biological Sciences, The Center for Neuroscience Research, The RNA Institute, University at Albany, Albany, New York, USA
| | - C Ron Yu
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
- Department of Cell Biology and Physiology, University of Kansas School of Medicine, Kansas City, Missouri, USA
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2
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Rufenacht KE, Asson AJ, Hossain K, Santoro SW. The influence of olfactory experience on the birthrates of olfactory sensory neurons with specific odorant receptor identities. Genesis 2024; 62:e23611. [PMID: 38888221 PMCID: PMC11189617 DOI: 10.1002/dvg.23611] [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: 04/26/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/20/2024]
Abstract
Olfactory sensory neurons (OSNs) are one of a few neuron types that are generated continuously throughout life in mammals. The persistence of olfactory sensory neurogenesis beyond early development has long been thought to function simply to replace neurons that are lost or damaged through exposure to environmental insults. The possibility that olfactory sensory neurogenesis may also serve an adaptive function has received relatively little consideration, largely due to the assumption that the generation of new OSNs is stochastic with respect to OSN subtype, as defined by the single odorant receptor gene that each neural precursor stochastically chooses for expression out of hundreds of possibilities. Accordingly, the relative birthrates of different OSN subtypes are predicted to be constant and impervious to olfactory experience. This assumption has been called into question, however, by evidence that the birthrates of specific OSN subtypes can be selectively altered by manipulating olfactory experience through olfactory deprivation, enrichment, and conditioning paradigms. Moreover, studies of recovery of the OSN population following injury provide further evidence that olfactory sensory neurogenesis may not be strictly stochastic with respect to subtype. Here we review this evidence and consider mechanistic and functional implications of the prospect that specific olfactory experiences can regulate olfactory sensory neurogenesis rates in a subtype-selective manner.
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Affiliation(s)
- Karlin E Rufenacht
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexa J Asson
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kawsar Hossain
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Stephen W Santoro
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
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3
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Azzopardi SA, Lu HY, Monette S, Rabinowitsch AI, Salmon JE, Matsunami H, Blobel CP. Role of iRhom2 in Olfaction: Implications for Odorant Receptor Regulation and Activity-Dependent Adaptation. Int J Mol Sci 2024; 25:6079. [PMID: 38892263 PMCID: PMC11173328 DOI: 10.3390/ijms25116079] [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: 04/08/2024] [Revised: 05/23/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
The cell surface metalloprotease ADAM17 (a disintegrin and metalloprotease 17) and its binding partners iRhom2 and iRhom1 (inactive Rhomboid-like proteins 1 and 2) modulate cell-cell interactions by mediating the release of membrane proteins such as TNFα (Tumor necrosis factor α) and EGFR (Epidermal growth factor receptor) ligands from the cell surface. Most cell types express both iRhoms, though myeloid cells exclusively express iRhom2, and iRhom1 is the main iRhom in the mouse brain. Here, we report that iRhom2 is uniquely expressed in olfactory sensory neurons (OSNs), highly specialized cells expressing one olfactory receptor (OR) from a repertoire of more than a thousand OR genes in mice. iRhom2-/- mice had no evident morphological defects in the olfactory epithelium (OE), yet RNAseq analysis revealed differential expression of a small subset of ORs. Notably, while the majority of ORs remain unaffected in iRhom2-/- OE, OSNs expressing ORs that are enriched in iRhom2-/- OE showed fewer gene expression changes upon odor environmental changes than the majority of OSNs. Moreover, we discovered an inverse correlation between the expression of iRhom2 compared to OSN activity genes and that odor exposure negatively regulates iRhom2 expression. Given that ORs are specialized G-protein coupled receptors (GPCRs) and many GPCRs activate iRhom2/ADAM17, we investigated if ORs could activate iRhom2/ADAM17. Activation of an olfactory receptor that is ectopically expressed in keratinocytes (OR2AT4) by its agonist Sandalore leads to ERK1/2 phosphorylation, likely via an iRhom2/ADAM17-dependent pathway. Taken together, these findings point to a mechanism by which odor stimulation of OSNs activates iRhom2/ADAM17 catalytic activity, resulting in downstream transcriptional changes to the OR repertoire and activity genes, and driving a negative feedback loop to downregulate iRhom2 expression.
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Affiliation(s)
- Stephanie A. Azzopardi
- Weill Cornell Medicine/Rockefeller University/Memorial Sloan-Kettering Cancer Center, Tri-Institutional MD-PhD Program, New York, NY 10021, USA; (S.A.A.); (A.I.R.)
- Physiology, Biophysics and Systems Biology Program, Weill Cornell Medicine, New York, NY 10021, USA
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, NY 10021, USA
| | - Hsiu-Yi Lu
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA;
| | - Sebastien Monette
- Tri-Institutional Laboratory of Comparative Pathology, Hospital for Special Surgery, Memorial Sloan Kettering Cancer Center, The Rockefeller University, Weill Cornell Medicine, New York, NY 10021, USA;
| | - Ariana I. Rabinowitsch
- Weill Cornell Medicine/Rockefeller University/Memorial Sloan-Kettering Cancer Center, Tri-Institutional MD-PhD Program, New York, NY 10021, USA; (S.A.A.); (A.I.R.)
- Department of Biochemistry, Cellular and Molecular Biology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jane E. Salmon
- Autoimmunity and Inflammation Program, Hospital for Special Surgery, New York, NY 10021, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA;
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710, USA
| | - Carl P. Blobel
- Weill Cornell Medicine/Rockefeller University/Memorial Sloan-Kettering Cancer Center, Tri-Institutional MD-PhD Program, New York, NY 10021, USA; (S.A.A.); (A.I.R.)
- Physiology, Biophysics and Systems Biology Program, Weill Cornell Medicine, New York, NY 10021, USA
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, NY 10021, USA
- Department of Biochemistry, Cellular and Molecular Biology, Weill Cornell Medicine, New York, NY 10021, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
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4
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Yusuf N, Monahan K. Epigenetic programming of stochastic olfactory receptor choice. Genesis 2024; 62:e23593. [PMID: 38562011 PMCID: PMC11003729 DOI: 10.1002/dvg.23593] [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: 11/27/2023] [Revised: 03/01/2024] [Accepted: 03/15/2024] [Indexed: 04/04/2024]
Abstract
The mammalian sense of smell relies upon a vast array of receptor proteins to detect odorant compounds present in the environment. The proper deployment of these receptor proteins in olfactory sensory neurons is orchestrated by a suite of epigenetic processes that remodel the olfactory genes in differentiating neuronal progenitors. The goal of this review is to elucidate the central role of gene regulatory processes acting in neuronal progenitors of olfactory sensory neurons that lead to a singular expression of an odorant receptor in mature olfactory sensory neurons. We begin by describing the principal features of odorant receptor gene expression in mature olfactory sensory neurons. Next, we delineate our current understanding of how these features emerge from multiple gene regulatory mechanisms acting in neuronal progenitors. Finally, we close by discussing the key gaps in our understanding of how these regulatory mechanisms work and how they interact with each other over the course of differentiation.
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Affiliation(s)
- Nusrath Yusuf
- Division of Life Sciences-Molecular Biology and Biochemistry Department, Rutgers University-New Brunswick, New Brunswick, New Jersey, USA
| | - Kevin Monahan
- Division of Life Sciences-Molecular Biology and Biochemistry Department, Rutgers University-New Brunswick, New Brunswick, New Jersey, USA
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Hossain K, Smith M, Santoro SW. In mice, discrete odors can selectively promote the neurogenesis of sensory neuron subtypes that they stimulate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.579748. [PMID: 38405728 PMCID: PMC10888860 DOI: 10.1101/2024.02.10.579748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
In mammals, olfactory sensory neurons (OSNs) are born throughout life, presumably solely to replace neurons lost via turnover or injury. This assumption follows from the hypothesis that olfactory neurogenesis is strictly stochastic with respect to neuron subtype, as defined by the single odorant receptor allele that each neural precursor stochastically chooses out of hundreds of possibilities. This hypothesis is challenged by recent findings that the birthrates of a fraction of subtypes are selectively diminished by olfactory deprivation. These findings raise questions about how, and why, olfactory stimuli are required to promote the neurogenesis of some OSN subtypes, including whether the stimuli are generic (e.g., broadly activating odors or mechanical stimuli) or specific (e.g., discrete odorants). Based on RNA-seq and scRNA-seq analyses, we hypothesized that the neurogenic stimuli are specific odorants that selectively activate the same OSN subtypes whose birthrates are accelerated. In support of this, we have found, using subtype-specific OSN birthdating, that exposure to male and musk odors can accelerate the birthrates of responsive OSNs. Collectively, our findings reveal that certain odor experiences can selectively "amplify" specific OSN subtypes, and that persistent OSN neurogenesis may serve, in part, an adaptive function.
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Affiliation(s)
- Kawsar Hossain
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Madeline Smith
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Stephen W Santoro
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
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6
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Shi X, Yang Y, Ma X, Zhou Y, Guo Z, Wang C, Liu J. Probabilistic cell/domain-type assignment of spatial transcriptomics data with SpatialAnno. Nucleic Acids Res 2023; 51:e115. [PMID: 37941153 PMCID: PMC10711557 DOI: 10.1093/nar/gkad1023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 10/03/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023] Open
Abstract
In the analysis of both single-cell RNA sequencing (scRNA-seq) and spatially resolved transcriptomics (SRT) data, classifying cells/spots into cell/domain types is an essential analytic step for many secondary analyses. Most of the existing annotation methods have been developed for scRNA-seq datasets without any consideration of spatial information. Here, we present SpatialAnno, an efficient and accurate annotation method for spatial transcriptomics datasets, with the capability to effectively leverage a large number of non-marker genes as well as 'qualitative' information about marker genes without using a reference dataset. Uniquely, SpatialAnno estimates low-dimensional embeddings for a large number of non-marker genes via a factor model while promoting spatial smoothness among neighboring spots via a Potts model. Using both simulated and four real spatial transcriptomics datasets from the 10x Visium, ST, Slide-seqV1/2, and seqFISH platforms, we showcase the method's improved spatial annotation accuracy, including its robustness to the inclusion of marker genes for irrelevant cell/domain types and to various degrees of marker gene misspecification. SpatialAnno is computationally scalable and applicable to SRT datasets from different platforms. Furthermore, the estimated embeddings for cellular biological effects facilitate many downstream analyses.
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Affiliation(s)
- Xingjie Shi
- KLATASDS-MOE, Academy of Statistics and Interdisciplinary Sciences, School of Statistics, East China Normal University, Shanghai 200062, China
| | - Yi Yang
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210018, China
| | - Xiaohui Ma
- College of Life Sciences, Nanjing University, Nanjing 210033, China
| | - Yong Zhou
- KLATASDS-MOE, Academy of Statistics and Interdisciplinary Sciences, School of Statistics, East China Normal University, Shanghai 200062, China
| | - Zhenxing Guo
- School of Data Science, The Chinese University of Hong Kong-Shenzhen, Shenzhen 518172, China
| | - Chaolong Wang
- Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Jin Liu
- School of Data Science, The Chinese University of Hong Kong-Shenzhen, Shenzhen 518172, China
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7
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Hossain K, Smith M, Santoro SW. A histological protocol for quantifying the birthrates of specific subtypes of olfactory sensory neurons in mice. STAR Protoc 2023; 4:102432. [PMID: 37436902 PMCID: PMC10511921 DOI: 10.1016/j.xpro.2023.102432] [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: 04/06/2023] [Revised: 05/16/2023] [Accepted: 06/12/2023] [Indexed: 07/14/2023] Open
Abstract
Mammals typically have hundreds of distinct olfactory sensory neuron subtypes, each defined by expression of a specific odorant receptor gene, which undergo neurogenesis throughout life at rates that can depend on olfactory experience. Here, we present a protocol to quantify the birthrates of specific neuron subtypes via the simultaneous detection of corresponding receptor mRNAs and 5-ethynyl-2'-deoxyuridine. For preparation prior to beginning the protocol, we detail procedures for generating odorant receptor-specific riboprobes and experimental mouse olfactory epithelial tissue sections. For complete details on the use and execution of this protocol, please refer to van der Linden et al. (2020).1.
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Affiliation(s)
- Kawsar Hossain
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Molecular and Cellular Life Sciences Program, University of Wyoming, Laramie, WY 82071, USA
| | - Madeline Smith
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Stephen W Santoro
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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Gunder N, Dörig P, Witt M, Welge-Lüssen A, Menzel S, Hummel T. Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview. HNO 2023; 71:35-43. [PMID: 36734997 PMCID: PMC9897160 DOI: 10.1007/s00106-022-01249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2022] [Indexed: 02/04/2023]
Abstract
Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.
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Affiliation(s)
- N Gunder
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - P Dörig
- Universitäts-HNO Klinik Basel, Basel, Switzerland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Germany
| | | | - S Menzel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - T Hummel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
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9
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Kraus A, Garcia B, Ma J, Herrera KJ, Zwaka H, Harpaz R, Wong RY, Engert F, Salinas I. Olfactory detection of viruses shapes brain immunity and behavior in zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533129. [PMID: 37034630 PMCID: PMC10081220 DOI: 10.1101/2023.03.17.533129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Olfactory sensory neurons (OSNs) are constantly exposed to pathogens, including viruses. However, serious brain infection via the olfactory route rarely occurs. When OSNs detect a virus, they coordinate local antiviral immune responses to stop virus progression to the brain. Despite effective immune control in the olfactory periphery, pathogen-triggered neuronal signals reach the CNS via the olfactory bulb (OB). We hypothesized that neuronal detection of a virus by OSNs initiates neuroimmune responses in the OB that prevent pathogen invasion. Using zebrafish ( Danio rerio ) as a model, we demonstrate viral-specific neuronal activation of OSNs projecting into the OB, indicating that OSNs are electrically activated by viruses. Further, behavioral changes are seen in both adult and larval zebrafish after viral exposure. By profiling the transcription of single cells in the OB after OSNs are exposed to virus, we found that both microglia and neurons enter a protective state. Microglia and macrophage populations in the OB respond within minutes of nasal viral delivery followed decreased expression of neuronal differentiation factors and enrichment of genes in the neuropeptide signaling pathway in neuronal clusters. Pituitary adenylate-cyclase-activating polypeptide ( pacap ), a known antimicrobial, was especially enriched in a neuronal cluster. We confirm that PACAP is antiviral in vitro and that PACAP expression increases in the OB 1 day post-viral treatment. Our work reveals how encounters with viruses in the olfactory periphery shape the vertebrate brain by inducing antimicrobial programs in neurons and by altering host behavior.
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Bhatia-Dey N, Csoka AB, Heinbockel T. Chemosensory Ability and Sensitivity in Health and Disease: Epigenetic Regulation and COVID-19. Int J Mol Sci 2023; 24:ijms24044179. [PMID: 36835589 PMCID: PMC9959623 DOI: 10.3390/ijms24044179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
Throughout the animal kingdom, our two chemical senses, olfaction and gustation, are defined by two primary factors: genomic architecture of the organisms and their living environment. During the past three years of the global COVID-19 pandemic, these two sensory modalities have drawn much attention at the basic science and clinical levels because of the strong association of olfactory and gustatory dysfunction with viral infection. Loss of our sense of smell alone, or together with a loss of taste, has emerged as a reliable indicator of COVID-19 infection. Previously, similar dysfunctions have been detected in a large cohort of patients with chronic conditions. The research focus remains on understanding the persistence of olfactory and gustatory disturbances in the post-infection phase, especially in cases with long-term effect of infection (long COVID). Also, both sensory modalities show consistent age-related decline in studies aimed to understand the pathology of neurodegenerative conditions. Some studies using classical model organisms show an impact on neural structure and behavior in offspring as an outcome of parental olfactory experience. The methylation status of specific odorant receptors, activated in parents, is passed on to the offspring. Furthermore, experimental evidence indicates an inverse correlation of gustatory and olfactory abilities with obesity. Such diverse lines of evidence emerging from basic and clinical research studies indicate a complex interplay of genetic factors, evolutionary forces, and epigenetic alterations. Environmental factors that regulate gustation and olfaction could induce epigenetic modulation. However, in turn, such modulation leads to variable effects depending on genetic makeup and physiological status. Therefore, a layered regulatory hierarchy remains active and is passed on to multiple generations. In the present review, we attempt to understand the experimental evidence that indicates variable regulatory mechanisms through multilayered and cross-reacting pathways. Our analytical approach will add to enhancement of prevailing therapeutic interventions and bring to the forefront the significance of chemosensory modalities for the evaluation and maintenance of long-term health.
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Frey T, Kwadha CA, Haag F, Pelletier J, Wallin EA, Holgersson E, Hedenström E, Bohman B, Bengtsson M, Becher PG, Krautwurst D, Witzgall P. The human odorant receptor OR10A6 is tuned to the pheromone of the commensal fruit fly Drosophila melanogaster. iScience 2022; 25:105269. [PMID: 36300000 PMCID: PMC9589189 DOI: 10.1016/j.isci.2022.105269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/10/2022] [Accepted: 09/29/2022] [Indexed: 12/03/2022] Open
Abstract
All living things speak chemistry. The challenge is to reveal the vocabulary, the odorants that enable communication across phylogenies and to translate them to physiological, behavioral, and ecological function. Olfactory receptors (ORs) interface animals with airborne odorants. Expression in heterologous cells makes it possible to interrogate single ORs and to identify cognate ligands. The cosmopolitan, anthropophilic strain of the vinegar fly Drosophila melanogaster depends on human resources and housing for survival. Curiously, humans sense the pheromone (Z)-4-undecenal (Z4-11Al) released by single fly females. A screening of all human ORs shows that the most highly expressed OR10A6 is tuned to Z4-11Al. Females of an ancestral African fly strain release a blend of Z4-11Al and Z4-9Al that produces a different aroma, which is how we distinguish these fly strains by nose. That flies and humans sense Z4-11Al via dedicated ORs shows how convergent evolution shapes communication channels between vertebrate and invertebrate animals. Humans sense the sex pheromone Z411-Al released by single Drosophila melanogaster females The most highly expressed human olfactory receptor OR10A6 is tuned to Z411-Al An African fly strain emits two aldehydes, which we distinguish from Z411-Al by nose Convergent evolution shapes chemical communication between phylogenies
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Affiliation(s)
- Tim Frey
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Charles A. Kwadha
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Franziska Haag
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Julien Pelletier
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Erika A. Wallin
- Department of Chemical Engineering, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
| | | | - Erik Hedenström
- Department of Chemical Engineering, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
| | - Björn Bohman
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Marie Bengtsson
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Paul G. Becher
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Dietmar Krautwurst
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Peter Witzgall
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden,Corresponding author
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12
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The facets of olfactory learning. Curr Opin Neurobiol 2022; 76:102623. [PMID: 35998474 DOI: 10.1016/j.conb.2022.102623] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/17/2022] [Accepted: 07/21/2022] [Indexed: 11/23/2022]
Abstract
Volatile chemicals in the environment provide ethologically important information to many animals. However, how animals learn to use this information is only beginning to be understood. This review highlights recent experimental advances elucidating olfactory learning in rodents, ranging from adaptations to the environment to task-dependent refinement and multisensory associations. The broad range of phenomena, mechanisms, and brain areas involved demonstrate the complex and multifaceted nature of olfactory learning.
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Koyama S, Kondo K, Ueha R, Kashiwadani H, Heinbockel T. Possible Use of Phytochemicals for Recovery from COVID-19-Induced Anosmia and Ageusia. Int J Mol Sci 2021; 22:8912. [PMID: 34445619 PMCID: PMC8396277 DOI: 10.3390/ijms22168912] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022] Open
Abstract
The year 2020 became the year of the outbreak of coronavirus, SARS-CoV-2, which escalated into a worldwide pandemic and continued into 2021. One of the unique symptoms of the SARS-CoV-2 disease, COVID-19, is the loss of chemical senses, i.e., smell and taste. Smell training is one of the methods used in facilitating recovery of the olfactory sense, and it uses essential oils of lemon, rose, clove, and eucalyptus. These essential oils were not selected based on their chemical constituents. Although scientific studies have shown that they improve recovery, there may be better combinations for facilitating recovery. Many phytochemicals have bioactive properties with anti-inflammatory and anti-viral effects. In this review, we describe the chemical compounds with anti- inflammatory and anti-viral effects, and we list the plants that contain these chemical compounds. We expand the review from terpenes to the less volatile flavonoids in order to propose a combination of essential oils and diets that can be used to develop a new taste training method, as there has been no taste training so far. Finally, we discuss the possible use of these in clinical settings.
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Affiliation(s)
- Sachiko Koyama
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Kenji Kondo
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
| | - Rumi Ueha
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
- Swallowing Center, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Hideki Kashiwadani
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan;
| | - Thomas Heinbockel
- Department of Anatomy, College of Medicine, Howard University, Washington, DC 20059, USA
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14
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Dörig P, Gunder N, Witt M, Welge-Lüssen A, Hummel T. [Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview]. HNO 2021; 69:623-632. [PMID: 33988723 PMCID: PMC8120256 DOI: 10.1007/s00106-021-01060-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 11/08/2022]
Abstract
Passagere oder permanente Riechstörungen können verschiedene Ursachen haben. Ganz aktuell berichtet eine Vielzahl von Patienten im Rahmen von COVID-19-Infektionen über ein fehlendes oder vermindertes Riechvermögen. In der Vergangenheit wurden vielfältige Therapieoptionen untersucht, diese variieren vom Riechtraining über Akupunktur und medikamentöse Therapien bis hin zur transkraniellen Magnetstimulation oder, z. B. bei ausgeprägten qualitativen Riechstörungen, der chirurgischen Resektion der Riechschleimhaut. Die Entwicklung einer bioelektrischen Nase, z. B. in Verbindung mit direkter elektrischer Stimulation des Bulbus olfactorius, oder die Transplantation von Riechschleimhaut oder von Stammzellen stellen Behandlungsmöglichkeiten der Zukunft dar. Die Grundlagen für diese Entwicklungen sowie der Stand des Wissens werden in der vorliegenden Arbeit erläutert.
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Affiliation(s)
- P Dörig
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz.
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Deutschland
| | - A Welge-Lüssen
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz
| | - T Hummel
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
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15
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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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16
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Vihani A, Hu XS, Gundala S, Koyama S, Block E, Matsunami H. Semiochemical responsive olfactory sensory neurons are sexually dimorphic and plastic. eLife 2020; 9:e54501. [PMID: 33231170 PMCID: PMC7732343 DOI: 10.7554/elife.54501] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 11/22/2020] [Indexed: 01/21/2023] Open
Abstract
Understanding how genes and experience work in concert to generate phenotypic variability will provide a better understanding of individuality. Here, we considered this in the main olfactory epithelium, a chemosensory structure with over a thousand distinct cell types in mice. We identified a subpopulation of olfactory sensory neurons, defined by receptor expression, whose abundances were sexually dimorphic. This subpopulation of olfactory sensory neurons was over-represented in sex-separated mice and robustly responsive to sex-specific semiochemicals. Sex-combined housing led to an attenuation of the dimorphic representations. Single-cell sequencing analysis revealed an axis of activity-dependent gene expression amongst a subset of the dimorphic OSN populations. Finally, the pro-apoptotic gene Baxwas necessary to generate the dimorphic representations. Altogether, our results suggest a role of experience and activity in influencing homeostatic mechanisms to generate a robust sexually dimorphic phenotype in the main olfactory epithelium.
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Affiliation(s)
- Aashutosh Vihani
- Department of Neurobiology, Neurobiology Graduate Program, Duke University Medical CenterDurhamUnited States
| | - Xiaoyang Serene Hu
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Sivaji Gundala
- Department of Chemistry, University at Albany, State University of New YorkAlbanyUnited States
| | - Sachiko Koyama
- School of Medicine, Medical Sciences, Indiana UniversityBloomingtonUnited States
| | - Eric Block
- Department of Chemistry, University at Albany, State University of New YorkAlbanyUnited States
| | - Hiroaki Matsunami
- Department of Neurobiology, Neurobiology Graduate Program, Duke University Medical CenterDurhamUnited States
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
- Duke Institute for Brain Sciences, Duke UniversityDurhamUnited States
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