1
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Ren H, Zhang R, Zhang H, Bian C. Ecnomotopic olfactory receptors in metabolic regulation. Biomed Pharmacother 2024; 179:117403. [PMID: 39241572 DOI: 10.1016/j.biopha.2024.117403] [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: 06/23/2024] [Revised: 08/22/2024] [Accepted: 09/02/2024] [Indexed: 09/09/2024] Open
Abstract
Olfactory receptors are seven-transmembrane G-protein-coupled receptors on the cell surface. Over the past few decades, evidence has been mounting that olfactory receptors are not unique to the nose and that their ectopic existence plays an integral role in extranasal diseases. Coupled with the discovery of many natural or synthetic odor-compound ligands, new roles of ecnomotopic olfactory receptors regulating blood glucose, obesity, blood pressure, and other metabolism-related diseases are emerging. Many well-known scientific journals have called for attention to extranasal functions of ecnomotopic olfactory receptors. Thus, the prospect of ecnomotopic olfactory receptors in drug target research has been greatly underestimated. Here, we have provided an overview for the role of ecnomotopic olfactory receptors in metabolic diseases, focusing on their effects on various metabolic tissues, and discussed the possible molecular biological and pathophysiological mechanisms, which provide the basis for drug development and clinical application targeting the function of ecnomotopic olfactory receptors via literature machine learning and screening.
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Affiliation(s)
- Huiwen Ren
- Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044, China
| | - Ruijing Zhang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Haibo Zhang
- Departments of Infectious Disease, the Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang 712000, China
| | - Che Bian
- Department of General Medicine, the Fourth Affiliated Hospital of China Medical University, Shenyang 110032, China.
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2
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Fang A, Yu CR. Activity-dependent formation of the topographic map and the critical period in the development of mammalian olfactory system. Genesis 2024; 62:e23586. [PMID: 38593162 PMCID: PMC11003738 DOI: 10.1002/dvg.23586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 04/11/2024]
Abstract
Neural activity influences every aspect of nervous system development. In olfactory systems, sensory neurons expressing the same odorant receptor project their axons to stereotypically positioned glomeruli, forming a spatial map of odorant receptors in the olfactory bulb. As individual odors activate unique combinations of glomeruli, this map forms the basis for encoding olfactory information. The establishment of this stereotypical olfactory map requires coordinated regulation of axon guidance molecules instructed by spontaneous activity. Recent studies show that sensory experiences also modify innervation patterns in the olfactory bulb, especially during a critical period of the olfactory system development. This review examines evidence in the field to suggest potential mechanisms by which various aspects of neural activity regulate axon targeting. We also discuss the precise functions served by neural plasticity during the critical period.
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Affiliation(s)
- Ai Fang
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - C. Ron Yu
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
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3
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Mariette J, Noël A, Louis T, Montagné N, Chertemps T, Jacquin-Joly E, Marion-Poll F, Sandoz JC. Transcuticular calcium imaging as a tool for the functional study of insect odorant receptors. Front Mol Neurosci 2023; 16:1182361. [PMID: 37645702 PMCID: PMC10461100 DOI: 10.3389/fnmol.2023.1182361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/12/2023] [Indexed: 08/31/2023] Open
Abstract
The primary actors in the detection of olfactory information in insects are odorant receptors (ORs), transmembrane proteins expressed at the dendrites of olfactory sensory neurons (OSNs). In order to decode the insect olfactome, many studies focus on the deorphanization of ORs (i.e., identification of their ligand), using various approaches involving heterologous expression coupled to neurophysiological recordings. The "empty neuron system" of the fruit fly Drosophila melanogaster is an appreciable host for insect ORs, because it conserves the cellular environment of an OSN. Neural activity is usually recorded using labor-intensive electrophysiological approaches (single sensillum recordings, SSR). In this study, we establish a simple method for OR deorphanization using transcuticular calcium imaging (TCI) at the level of the fly antenna. As a proof of concept, we used two previously deorphanized ORs from the cotton leafworm Spodoptera littoralis, a specialist pheromone receptor and a generalist plant odor receptor. We demonstrate that by co-expressing the GCaMP6s/m calcium probes with the OR of interest, it is possible to measure robust odorant-induced responses under conventional microscopy conditions. The tuning breadth and sensitivity of ORs as revealed using TCI were similar to those measured using single sensillum recordings (SSR). We test and discuss the practical advantages of this method in terms of recording duration and the simultaneous testing of several insects.
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Affiliation(s)
- Julia Mariette
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
| | - Amélie Noël
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
| | - Thierry Louis
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
| | - Nicolas Montagné
- Sorbonne Université, INRAE, CNRS, IRD, UPEC, Université Paris Cité, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
| | - Thomas Chertemps
- Sorbonne Université, INRAE, CNRS, IRD, UPEC, Université Paris Cité, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
| | - Emmanuelle Jacquin-Joly
- Sorbonne Université, INRAE, CNRS, IRD, UPEC, Université Paris Cité, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
| | - Frédéric Marion-Poll
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
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4
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Billesbølle CB, de March CA, van der Velden WJC, Ma N, Tewari J, Del Torrent CL, Li L, Faust B, Vaidehi N, Matsunami H, Manglik A. Structural basis of odorant recognition by a human odorant receptor. Nature 2023; 615:742-749. [PMID: 36922591 PMCID: PMC10580732 DOI: 10.1038/s41586-023-05798-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/06/2023] [Indexed: 03/17/2023]
Abstract
Our sense of smell enables us to navigate a vast space of chemically diverse odour molecules. This task is accomplished by the combinatorial activation of approximately 400 odorant G protein-coupled receptors encoded in the human genome1-3. How odorants are recognized by odorant receptors remains unclear. Here we provide mechanistic insight into how an odorant binds to a human odorant receptor. Using cryo-electron microscopy, we determined the structure of the active human odorant receptor OR51E2 bound to the fatty acid propionate. Propionate is bound within an occluded pocket in OR51E2 and makes specific contacts critical to receptor activation. Mutation of the odorant-binding pocket in OR51E2 alters the recognition spectrum for fatty acids of varying chain length, suggesting that odorant selectivity is controlled by tight packing interactions between an odorant and an odorant receptor. Molecular dynamics simulations demonstrate that propionate-induced conformational changes in extracellular loop 3 activate OR51E2. Together, our studies provide a high-resolution view of chemical recognition of an odorant by a vertebrate odorant receptor, providing insight into how this large family of G protein-coupled receptors enables our olfactory sense.
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Affiliation(s)
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
- Institut de Chimie des Substances Naturelles, UPR2301 CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Wijnand J C van der Velden
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Jeevan Tewari
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Claudia Llinas Del Torrent
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Universitat Autònoma Barcelona, Bellaterra, Barcelona, Spain
| | - Linus Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Bryan Faust
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA.
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA.
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC, USA.
| | - Aashish Manglik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA.
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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5
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Nomdedeu-Sancho G, Alsina B. Wiring the senses: Factors that regulate peripheral axon pathfinding in sensory systems. Dev Dyn 2023; 252:81-103. [PMID: 35972036 PMCID: PMC10087148 DOI: 10.1002/dvdy.523] [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: 05/11/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 01/04/2023] Open
Abstract
Sensory neurons of the head are the ones that transmit the information about the external world to our brain for its processing. Axons from cranial sensory neurons sense different chemoattractant and chemorepulsive molecules during the journey and in the target tissue to establish the precise innervation with brain neurons and/or receptor cells. Here, we aim to unify and summarize the available information regarding molecular mechanisms guiding the different afferent sensory axons of the head. By putting the information together, we find the use of similar guidance cues in different sensory systems but in distinct combinations. In vertebrates, the number of genes in each family of guidance cues has suffered a great expansion in the genome, providing redundancy, and robustness. We also discuss recently published data involving the role of glia and mechanical forces in shaping the axon paths. Finally, we highlight the remaining questions to be addressed in the field.
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Affiliation(s)
- Gemma Nomdedeu-Sancho
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
| | - Berta Alsina
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
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6
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Habif JC, Xie C, Martens JR. Visualizing and Manipulating Olfactory Cilia Through Viral Delivery Coupled with En Face Imaging of Intact OE. Methods Mol Biol 2023; 2710:1-18. [PMID: 37688720 DOI: 10.1007/978-1-0716-3425-7_1] [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] [Indexed: 09/11/2023]
Abstract
Olfactory cilia are the obligate transducers of the odorant signal, and thus their study has been a focus of investigation in the olfactory field. Various methodologies have been established to visualize the cilia of olfactory sensory neurons; however, these approaches are limited to static imaging and often lack the ability to resolve individual cilia projecting from solitary neurons in the postnatal mouse. Here we detail a procedure of the visualization of olfactory cilia by ectopic expression of fluorescently tagged proteins. The procedure can be used for the observation and manipulation of the olfactory cilia and ciliary proteins in both static and dynamic conditions.
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Affiliation(s)
- Julien C Habif
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Chao Xie
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA.
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA.
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7
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Alhadyan SK, Sivaraman V, Onyenwoke RU. E-cigarette Flavors, Sensory Perception, and Evoked Responses. Chem Res Toxicol 2022; 35:2194-2209. [PMID: 36480683 DOI: 10.1021/acs.chemrestox.2c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.
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Affiliation(s)
- Shatha K Alhadyan
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Rob U Onyenwoke
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States.,Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, North Carolina 27707, United States
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8
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Ben Khemis I, Noureddine O, Aouaini F, Salamah M. Aljaloud A, Nasr S, Ben Lamine A. Indirect characterizations of mOR-EG: Modeling analysis of five concentration-olfactory response curves via an advanced monolayer adsorption model. Int J Biol Macromol 2022; 222:1277-1286. [DOI: 10.1016/j.ijbiomac.2022.09.251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/18/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022]
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9
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Current Theories in Odorant Binding. CURRENT OTORHINOLARYNGOLOGY REPORTS 2022. [DOI: 10.1007/s40136-022-00437-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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10
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Yasunaga M, Takai E, Hattori S, Tatematsu K, Kuroda S. Effects of 3-octen-2-one on human olfactory receptor responses to vanilla flavor. Biosci Biotechnol Biochem 2022; 86:1562-1569. [PMID: 36073350 DOI: 10.1093/bbb/zbac147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022]
Abstract
Most of the odors that humans perceive daily are complex odors. It is believed that the modulation, enhancement, and suppression of overall complex odors are caused by interactions between odor molecules. In this study, to understand the interaction between odor molecules at the level of human olfactory receptor responses, the effects of 3-octen-2-one, which has been shown to modulate vanilla flavors, were analyzed using a human olfactory receptor sensor that uses all human olfactory receptors (388 types) as sensing molecules. As a result, the response intensity of 1 common receptor (OR1D2) was synergistically enhanced in vanilla flavor with 3-octen-2-one compared with vanilla flavor, and the response of 1 receptor (OR5K1) to vanilla flavor was completely suppressed. These results strongly suggested that the response of human olfactory receptors to complex odors is enhanced or suppressed by relatively few other odor molecules.
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Affiliation(s)
- Motoki Yasunaga
- Analytical Research Department, Soda Aromatic Co., Ltd., 1573-4 Funakata, Noda, Chiba 270-0233Japan
| | - Eiji Takai
- Analytical Research Department, Soda Aromatic Co., Ltd., 1573-4 Funakata, Noda, Chiba 270-0233Japan
| | - Shoji Hattori
- Analytical Research Department, Soda Aromatic Co., Ltd., 1573-4 Funakata, Noda, Chiba 270-0233Japan
| | - Kenji Tatematsu
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047Japan.,R&D Center, Komi Hakko Co., Technoalliance C Bldg. 3F, Osaka University, 2-8 Yamadaoka, Suita, Osaka 565-0871Japan
| | - Shun'ichi Kuroda
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047Japan.,R&D Center, Komi Hakko Co., Technoalliance C Bldg. 3F, Osaka University, 2-8 Yamadaoka, Suita, Osaka 565-0871Japan
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11
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Barwich AS, Lloyd EA. More than meets the AI: The possibilities and limits of machine learning in olfaction. Front Neurosci 2022; 16:981294. [PMID: 36117640 PMCID: PMC9475214 DOI: 10.3389/fnins.2022.981294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the relation between chemical structure and sensory quality with Big Data. These studies advanced computational models of the olfactory stimulus, utilizing artificial intelligence to mine for clear correlations between chemistry and psychophysics. Computational perspectives promised to solve the mystery of olfaction with more data and better data processing tools. None of them succeeded, however, and it matters as to why this is the case. This article argues that we should be deeply skeptical about the trend to black-box the sensory system's biology in our theories of perception. Instead, we need to ground both stimulus models and psychophysical data on real causal-mechanistic explanations of the olfactory system. The central question is: Would knowledge of biology lead to a better understanding of the stimulus in odor coding than the one utilized in current machine learning models? That is indeed the case. Recent studies about receptor behavior have revealed that the olfactory system operates by principles not captured in current stimulus-response models. This may require a fundamental revision of computational approaches to olfaction, including its psychological effects. To analyze the different research programs in olfaction, we draw on Lloyd's "Logic of Research Questions," a philosophical framework which assists scientists in explicating the reasoning, conceptual commitments, and problems of a modeling approach in question.
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Affiliation(s)
- Ann-Sophie Barwich
- Department of History and Philosophy of Science and Medicine, College of Arts and Sciences, Indiana University Bloomington, Bloomington, IN, United States
- Cognitive Science Program, College of Arts and Sciences, Indiana University, Bloomington, IN, United States
| | - Elisabeth A. Lloyd
- Department of History and Philosophy of Science and Medicine, College of Arts and Sciences, Indiana University Bloomington, Bloomington, IN, United States
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12
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Liu W, Zheng Y, Zhang C, Chen L, Zhuang H, Yao G, Ren H, Liu Y. A biomimetic olfactory recognition system for the discrimination of Chinese liquor aromas. Food Chem 2022; 386:132841. [PMID: 35367803 DOI: 10.1016/j.foodchem.2022.132841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 11/04/2022]
Abstract
Aroma is an important attribute influencing the perceived quality of Chinese liquors, with each liquor characterized by a unique collection of volatile chemicals. Here, a biomimetic olfactory recognition system combining an optimal panel of 10 mouse odorant receptors with back propagation neural network model was designed to discriminate the aromas of Chinese liquors. Our system shows an excellent predictive capacity with an average accuracy of 96.5% to discriminate liquors of different aroma types, as well as those of different brands and ageing years within the same aroma type. A total of 124 interactions between liquor aroma compounds and odorant receptors were further elucidated to understand odorant coding at the molecular level, including 14 newly deorphaned odorant receptors. Our work represents a proof of concept for combining receptors and machine learning in the discrimination of complex odorant stimuli.
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Affiliation(s)
- Weihong Liu
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China.
| | - Yu Zheng
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Chen Zhang
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Lin Chen
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Hanyi Zhuang
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Guojun Yao
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Hang Ren
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China
| | - Yingjian Liu
- Intelligent Perception Lab, Hanwang Technology Co., Ltd., 100193 Beijing, China.
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13
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Xu R, Cong X, Zheng Q, Xu L, Ni MJ, de March CA, Matsunami H, Golebiowski J, Ma M, Yu Y. Interactions among key residues regulate mammalian odorant receptor trafficking. FASEB J 2022; 36:e22384. [PMID: 35639289 DOI: 10.1096/fj.202200116rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 11/11/2022]
Abstract
Odorant receptors (ORs) expressed in mammalian olfactory sensory neurons are essential for the sense of smell. However, structure-function studies of many ORs are hampered by unsuccessful heterologous expression. To understand and eventually overcome this bottleneck, we performed heterologous expression and functional assays of over 80 OR variants and chimeras. Combined with literature data and machine learning, we found that the transmembrane domain 4 (TM4) and its interactions with neighbor residues are important for OR functional expression. The data highlight critical roles of T4.62 therein. ORs that fail to reach the cell membrane can be rescued by modifications in TM4. Consequently, such modifications in MOR256-3 (Olfr124) also alter OR responses to odorants. T1614.62 P causes the retention of MOR256-3 in the endoplasmic reticulum (ER), while T1614.62 P/T1484.49 A reverses the retention and makes receptor trafficking to cell membrane. This study offers new clues toward wide-range functional studies of mammalian ORs.
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Affiliation(s)
- Rui Xu
- School of Life Sciences, Shanghai University, Shanghai, People's Republic of China
| | - Xiaojing Cong
- Institut de Chimie de Nice UMR7272, CNRS, Université Côte d'Azur, Nice, France.,Institut de Génomique Fonctionnelle, University of Montpellier, CNRS, INSERM, Montpellier Cedex 5, 34094, France
| | - Qian Zheng
- School of Life Sciences, Shanghai University, Shanghai, People's Republic of China
| | - Lun Xu
- Ear, Nose & Throat Institute, Department of Otolaryngology, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China
| | - Mengjue J Ni
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jérôme Golebiowski
- Institut de Chimie de Nice UMR7272, CNRS, Université Côte d'Azur, Nice, France.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yiqun Yu
- Ear, Nose & Throat Institute, Department of Otolaryngology, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China.,Clinical and Research Center for Olfactory Disorders, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China
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14
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Functional analysis of human olfactory receptors with a high basal activity using LNCaP cell line. PLoS One 2022; 17:e0267356. [PMID: 35446888 PMCID: PMC9022881 DOI: 10.1371/journal.pone.0267356] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 04/06/2022] [Indexed: 11/19/2022] Open
Abstract
Humans use a family of more than 400 olfactory receptors (ORs) to detect odorants. However, deorphanization of ORs is a critical issue because the functional properties of more than 80% of ORs remain unknown, thus, hampering our understanding of the relationship between receptor function and perception. HEK293 cells are the most commonly used heterologous expression system to determine the function of a given OR; however, they cannot functionally express a majority of ORs probably due to a lack of factor(s) required in cells in which ORs function endogenously. Interestingly, ORs have been known to be expressed in a variety of cells outside the nose and play critical physiological roles. These findings prompted us to test the capacity of cells to functionally express a specific repertoire of ORs. In this study, we selected three cell lines that endogenously express functional ORs. We demonstrated that human prostate carcinoma (LNCaP) cell lines successfully identified novel ligands for ORs that were not recognized when expressed in HEK293 cells. Further experiments suggested that the LNCaP cell line was effective for functional expression of ORs, especially with a high basal activity, which impeded the sensitive detection of ligand-mediated activity of ORs. This report provides an efficient functional assay system for a specific repertoire of ORs that cannot be characterized in current cell systems.
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15
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Francia S, Lodovichi C. The role of the odorant receptors in the formation of the sensory map. BMC Biol 2021; 19:174. [PMID: 34452614 PMCID: PMC8394594 DOI: 10.1186/s12915-021-01116-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
In the olfactory system, odorant receptors (ORs) expressed at the cell membrane of olfactory sensory neurons detect odorants and direct sensory axons toward precise target locations in the brain, reflected in the presence of olfactory sensory maps. This dual role of ORs is corroborated by their subcellular expression both in cilia, where they bind odorants, and at axon terminals, a location suitable for axon guidance cues. Here, we provide an overview and discuss previous work on the role of ORs in establishing the topographic organization of the olfactory system and recent findings on the mechanisms of activation and function of axonal ORs.
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Affiliation(s)
- Simona Francia
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy
| | - Claudia Lodovichi
- Veneto Institute of Molecular Medicine, Padua, Italy. .,Neuroscience Institute CNR, Via Orus 2, 35129, Padua, Italy. .,Department of Biomedical Sciences, University of Padua, Padua, Italy. .,Padova Neuroscience Center, Padua, Italy.
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16
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Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
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Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
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17
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A Confocal Microscopic Study of Gene Transfer into the Mesencephalic Tegmentum of Juvenile Chum Salmon, Oncorhynchus keta, Using Mouse Adeno-Associated Viral Vectors. Int J Mol Sci 2021; 22:ijms22115661. [PMID: 34073457 PMCID: PMC8199053 DOI: 10.3390/ijms22115661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 11/17/2022] Open
Abstract
To date, data on the presence of adenoviral receptors in fish are very limited. In the present work, we used mouse recombinant adeno-associated viral vectors (rAAV) with a calcium indicator of the latest generation GCaMP6m that are usually applied for the dorsal hippocampus of mice but were not previously used for gene delivery into fish brain. The aim of our work was to study the feasibility of transduction of rAAV in the mouse hippocampus into brain cells of juvenile chum salmon and subsequent determination of the phenotype of rAAV-labeled cells by confocal laser scanning microscopy (CLSM). Delivery of the gene in vivo was carried out by intracranial injection of a GCaMP6m-GFP-containing vector directly into the mesencephalic tegmentum region of juvenile (one-year-old) chum salmon, Oncorhynchus keta. AAV incorporation into brain cells of the juvenile chum salmon was assessed at 1 week after a single injection of the vector. AAV expression in various areas of the thalamus, pretectum, posterior-tuberal region, postcommissural region, medial and lateral regions of the tegmentum, and mesencephalic reticular formation of juvenile O. keta was evaluated using CLSM followed by immunohistochemical analysis of the localization of the neuron-specific calcium binding protein HuCD in combination with nuclear staining with DAPI. The results of the analysis showed partial colocalization of cells expressing GCaMP6m-GFP with red fluorescent HuCD protein. Thus, cells of the thalamus, posterior tuberal region, mesencephalic tegmentum, cells of the accessory visual system, mesencephalic reticular formation, hypothalamus, and postcommissural region of the mesencephalon of juvenile chum salmon expressing GCaMP6m-GFP were attributed to the neuron-specific line of chum salmon brain cells, which indicates the ability of hippocampal mammal rAAV to integrate into neurons of the central nervous system of fish with subsequent expression of viral proteins, which obviously indicates the neuronal expression of a mammalian adenoviral receptor homolog by juvenile chum salmon neurons.
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18
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Shepherd GM, Rowe TB, Greer CA. An Evolutionary Microcircuit Approach to the Neural Basis of High Dimensional Sensory Processing in Olfaction. Front Cell Neurosci 2021; 15:658480. [PMID: 33994949 PMCID: PMC8120314 DOI: 10.3389/fncel.2021.658480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/30/2021] [Indexed: 11/16/2022] Open
Abstract
Odor stimuli consist of thousands of possible molecules, each molecule with many different properties, each property a dimension of the stimulus. Processing these high dimensional stimuli would appear to require many stages in the brain to reach odor perception, yet, in mammals, after the sensory receptors this is accomplished through only two regions, the olfactory bulb and olfactory cortex. We take a first step toward a fundamental understanding by identifying the sequence of local operations carried out by microcircuits in the pathway. Parallel research provided strong evidence that processed odor information is spatial representations of odor molecules that constitute odor images in the olfactory bulb and odor objects in olfactory cortex. Paleontology provides a unique advantage with evolutionary insights providing evidence that the basic architecture of the olfactory pathway almost from the start ∼330 million years ago (mya) has included an overwhelming input from olfactory sensory neurons combined with a large olfactory bulb and olfactory cortex to process that input, driven by olfactory receptor gene duplications. We identify a sequence of over 20 microcircuits that are involved, and expand on results of research on several microcircuits that give the best insights thus far into the nature of the high dimensional processing.
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Affiliation(s)
- Gordon M. Shepherd
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
| | - Timothy B. Rowe
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States
| | - Charles A. Greer
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
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19
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Corey EA, Zolotukhin S, Ache BW, Ukhanov K. Mixture interactions at mammalian olfactory receptors are dependent on the cellular environment. Sci Rep 2021; 11:9278. [PMID: 33927269 PMCID: PMC8085013 DOI: 10.1038/s41598-021-88601-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/07/2021] [Indexed: 02/02/2023] Open
Abstract
Functional characterization of mammalian olfactory receptors (ORs) remains a major challenge to ultimately understanding the olfactory code. Here, we compare the responses of the mouse Olfr73 ectopically expressed in olfactory sensory neurons using AAV gene delivery in vivo and expressed in vitro in cell culture. The response dynamics and concentration-dependence of agonists for the ectopically expressed Olfr73 were similar to those reported for the endogenous Olfr73, however the antagonism previously reported between its cognate agonist and several antagonists was not replicated in vivo. Expressing the OR in vitro reproduced the antagonism reported for short odor pulses, but not for prolonged odor exposure. Our findings suggest that both the cellular environment and the stimulus dynamics shape the functionality of Olfr73 and argue that characterizing ORs in 'native' conditions, rather than in vitro, provides a more relevant understanding of ligand-OR interactions.
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Affiliation(s)
- Elizabeth A Corey
- Whitney Laboratory, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Sergei Zolotukhin
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Barry W Ache
- Whitney Laboratory, University of Florida, Gainesville, FL, USA
- Department of Biology and Neuroscience, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Kirill Ukhanov
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA.
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20
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Sultana A, Tiash S. Improved DNA delivery using invasive E. coli DH10B in human cells by modified bactofection method. J Control Release 2021; 332:233-244. [PMID: 33561481 DOI: 10.1016/j.jconrel.2021.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/16/2021] [Accepted: 02/02/2021] [Indexed: 11/15/2022]
Abstract
E. coli mediated gene delivery faces a major drawback of low efficiency despite of being a safer alternative to viral vectors. This study showed a novel, simple and effective strategy to enhance invasive E. coli DH10B vector's efficiency in human epithelial cells. The bactofection efficiency of invasive E .coli vector was analyzed in nine cell lines. It demonstrated highest (16%) reporter gene (GFP) expression in cervical cells. Methods were employed to further enhance its efficiency by adding transfection reagents (trans-bactofection method) to promote entry into host cells, lysosomotropic reagents for escape from lysosomal degradation or antibiotics to lyse internalized bacteria. Increased bacterial entry, as elucidated from nil to 3% expression in liver cells, was obtained upon complexing bacteria with PULSin. Chloroquine mediated endosomal escape resulted in 7.2 folds increase whereas tetracycline addition to lyse internalized bacteria caused ≈90% of GFP in HeLa. Eventually, the combined effect of these three methods exhibited close to 100% GFP in cervical and remarkable increase of 138 folds in breast cells. This is the first study showing comparative study of vector's gene delivery ability in various epithelial cells of the human body with improving its delivery efficiency. These data demonstrated the potential of developed bactofection method to boost up the efficiency of other bacterial vectors also, which could further be used for effectual therapeutic gene delivery in human cells.
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Affiliation(s)
- Alviya Sultana
- School of Science, Monash University, Bandar Sunway, Malaysia.
| | - Snigdha Tiash
- Griffith Institute for Drug Discovery, Griffith University, Queensland, Australia.
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21
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Pushchina EV, Kapustyanov IA, Shamshurina EV, Varaksin AA. Labeling of Mesencephalic Tegmental
Neurons in a Juvenile Pacific Chum Salmon Oncorhynchus
keta with Mouse Hippocampal Adeno-Associated Viral Vectors. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021010087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Kalra S, Mittal A, Bajoria M, Mishra T, Maryam S, Sengupta D, Ahuja G. Challenges and possible solutions for decoding extranasal olfactory receptors. FEBS J 2020; 288:4230-4241. [PMID: 33085840 DOI: 10.1111/febs.15606] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022]
Abstract
Olfactory receptors are primarily known to be expressed in the olfactory epithelium of the nasal cavity and therefore assist in odor perception. With the advent of high-throughput omics technologies such as tissue microarray or RNA sequencing, a large number of olfactory receptors have been reported to be expressed in the nonolfactory tissues. Although these technologies uncovered the expression of these olfactory receptors in the nonchemosensory tissues, unfortunately, they failed to reveal the information about their cell type of origin. Accurate characterization of the cell types should be the first step towards devising cell type-specific assays for their functional evaluation. Single-cell RNA-sequencing technology resolved some of these apparent limitations and opened new means to interrogate the expression of these extranasal olfactory receptors at the single-cell resolution. Moreover, the availability of large-scale, multi-organ/species single-cell expression atlases offer ample resources for the systematic reannotation of these receptors in a cell type-specific manner. In this Viewpoint article, we discuss some of the technical limitations that impede the in-depth understanding of these extranasal olfactory receptors, with a special focus on odorant receptors. Moreover, we also propose a list of single cell-based omics technologies that could further promulgate the opportunity to decipher the regulatory network that drives the odorant receptors expression at atypical locations.
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Affiliation(s)
- Siddhant Kalra
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Aayushi Mittal
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Manisha Bajoria
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Tripti Mishra
- Pathfinder Research and Training Foundation, Greater Noida, India
| | - Sidrah Maryam
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Debarka Sengupta
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India.,Department of Computer Science and Engineering, Indraprastha Institute of Information Technology, New Delhi, India, India.,Centre for Artificial Intelligence, Indraprastha Institute of Information Technology, New Delhi, India.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gaurav Ahuja
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
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23
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Singh S, Singh PK, Umar A, Lohia P, Albargi H, Castañeda L, Dwivedi DK. 2D Nanomaterial-Based Surface Plasmon Resonance Sensors for Biosensing Applications. MICROMACHINES 2020; 11:E779. [PMID: 32824184 PMCID: PMC7463818 DOI: 10.3390/mi11080779] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/08/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022]
Abstract
The absorption and binding energy of material plays an important role with a large surface area and conductivity for the development of any sensing device. The newly grown 2D nanomaterials like black phosphorus transition metal dichalcogenides (TMDCs) or graphene have excellent properties for sensing devices' fabrication. This paper summarizes the progress in the area of the 2D nanomaterial-based surface plasmon resonance (SPR) sensor during last decade. The paper also focuses on the structure of Kretschmann configuration, the sensing principle of SPR, its characteristic parameters, application in various fields, and some important recent works related to SPR sensors have also been discussed, based on the present and future scope of this field. The present paper provides a platform for researchers to work in the field of 2D nanomaterial-based SPR sensors.
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Affiliation(s)
- Sachin Singh
- Amorphous Semiconductor Research Lab, Department of Physics and Material Science, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, India; (S.S.); (P.K.S.)
| | - Pravin Kumar Singh
- Amorphous Semiconductor Research Lab, Department of Physics and Material Science, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, India; (S.S.); (P.K.S.)
| | - Ahmad Umar
- Department of Chemistry, Faculty of Science and Arts, Najran University, Najran 11001, Saudi Arabia
- Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran 11001, Saudi Arabia;
| | - Pooja Lohia
- Department of Electronics and Communication Engineering, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, India;
| | - Hasan Albargi
- Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran 11001, Saudi Arabia;
- Department of Physics, Faculty of Science and Arts, Najran University, Najran 11001, Saudi Arabia
| | - L. Castañeda
- Sección de Estudios de Posgrado e Investigación de la Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón S/N, Casco de Santo Tomas, Alcaldía Miguel Hidalgo, C.P. 11340 Cd. de México, Mexico;
| | - D. K. Dwivedi
- Amorphous Semiconductor Research Lab, Department of Physics and Material Science, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, India; (S.S.); (P.K.S.)
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24
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Liu MT, Na M, Li Y, Biscoe MR, Ryan K. Conformational Sensing by a Mammalian Olfactory Receptor. Chemistry 2020; 26:11462-11469. [PMID: 32691933 DOI: 10.1002/chem.202001390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/22/2020] [Indexed: 01/08/2023]
Abstract
To identify odors, the mammalian nose deploys hundreds of olfactory receptors (ORs) from the rhodopsin-like class of the G protein-coupled receptor superfamily. Odorants having multiple rotatable bonds present a problem for the stereochemical shape-based matching process assumed to govern the sense of smell through OR-odorant recognition. We conformationally restricted the carbon chain of the odorant octanal to ask whether an OR can respond differently to different odorant conformations. By using calcium imaging to monitor signal transduction in sensory neurons expressing the mouse aldehyde OR, Olfr2, we found that the spatial position of the C7 and C8 carbon atoms of octanal, in relation to its -CHO group, determines whether an aliphatic aldehyde functions as an agonist, partial agonist or antagonist. Our experiments provide evidence that an odorant can manipulate an OR through its intrinsic conformational repertoire, in unexpected analogy to the photon-controlled aldehyde manipulation observed in rhodopsin.
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Affiliation(s)
- Min Ting Liu
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Mihwa Na
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Yadi Li
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Mark R Biscoe
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Kevin Ryan
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
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25
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Makeyeva Y, Nicol C, Ledger WL, Ryugo DK. Immunocytochemical Localization of Olfactory-signaling Molecules in Human and Rat Spermatozoa. J Histochem Cytochem 2020; 68:491-513. [PMID: 32603211 DOI: 10.1369/0022155420939833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Expression of olfactory receptors (ORs) in non-olfactory tissues has been widely reported over the last 20 years. Olfactory marker protein (OMP) is highly expressed in mature olfactory sensory neurons (mOSNs) of the olfactory epithelium. It is involved in the olfactory signal transduction pathway, which is mediated by well-conserved components, including ORs, olfactory G protein (Golf), and adenylyl cyclase 3 (AC3). OMP is widely expressed in non-olfactory tissues with an apparent preference for motile cells. We hypothesized that OMP is expressed in compartment-specific locations and co-localize with an OR, Golf, and AC3 in rat epididymal and human-ejaculated spermatozoa. We used immunocytochemistry to examine the expression patterns of OMP and OR6B2 (human OR, served as positive olfactory control) in experimentally induced modes of activation and determine whether there are any observable differences in proteins expression during the post-ejaculatory stages of spermatozoal functional maturation. We found that OMP was expressed in compartment-specific locations in human and rat spermatozoa. OMP was co-expressed with Golf and AC3 in rat spermatozoa and with OR6B2 in all three modes of activation (control, activated, and hyperactivated), and the mode of activation changed the co-expression pattern in acrosomal-reacted human spermatozoa. These observations suggest that OMP expression is a reliable indicator of OR-mediated chemoreception, may be used to identify ectopically expressed ORs, and could participate in second messenger signaling cascades that mediate fertility.
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Affiliation(s)
- Yuliya Makeyeva
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,Westfield Research Laboratories, School of Women's and Children's Health, Royal Hospital for Women, Sydney, NSW, Australia
| | - Christopher Nicol
- UNSW Sydney, Sydney, NSW, Australia, and Andrology Laboratory, NSW Health Pathology, Royal Hospital for Women, Sydney, NSW, Australia
| | - William L Ledger
- Fertility & Research Centre, Royal Hospital for Women, Sydney, NSW, Australia
| | - David K Ryugo
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,School of Medical Sciences, UNSW, Royal Hospital for Women, Sydney, NSW, Australia.,Department of Otolaryngology, Head, Neck & Skull Base Surgery, St. Vincent's Hospital, Royal Hospital for Women, Sydney, NSW, Australia
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26
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Xu L, Li W, Voleti V, Zou DJ, Hillman EMC, Firestein S. Widespread receptor-driven modulation in peripheral olfactory coding. Science 2020; 368:368/6487/eaaz5390. [PMID: 32273438 DOI: 10.1126/science.aaz5390] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 03/09/2020] [Indexed: 12/24/2022]
Abstract
Olfactory responses to single odors have been well characterized but in reality we are continually presented with complex mixtures of odors. We performed high-throughput analysis of single-cell responses to odor blends using Swept Confocally Aligned Planar Excitation (SCAPE) microscopy of intact mouse olfactory epithelium, imaging ~10,000 olfactory sensory neurons in parallel. In large numbers of responding cells, mixtures of odors did not elicit a simple sum of the responses to individual components of the blend. Instead, many neurons exhibited either antagonism or enhancement of their response in the presence of another odor. All eight odors tested acted as both agonists and antagonists at different receptors. We propose that this peripheral modulation of responses increases the capacity of the olfactory system to distinguish complex odor mixtures.
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Affiliation(s)
- Lu Xu
- Department of Biological Sciences, Columbia University in the City of New York, New York, NY, 10027, USA
| | - Wenze Li
- Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Sciences, Columbia University in the City of New York, New York, NY, 10027, USA
| | - Venkatakaushik Voleti
- Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Sciences, Columbia University in the City of New York, New York, NY, 10027, USA
| | - Dong-Jing Zou
- Department of Biological Sciences, Columbia University in the City of New York, New York, NY, 10027, USA
| | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Sciences, Columbia University in the City of New York, New York, NY, 10027, USA.
| | - Stuart Firestein
- Department of Biological Sciences, Columbia University in the City of New York, New York, NY, 10027, USA.
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27
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Sensory Lexicons and Formation Pathways of Off-Aromas in Dairy Ingredients: A Review. Molecules 2020; 25:molecules25030569. [PMID: 32012952 PMCID: PMC7037039 DOI: 10.3390/molecules25030569] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 11/18/2022] Open
Abstract
Consumers are becoming increasingly aware of the health benefits of dairy ingredients. However, products fortified with dairy proteins are experiencing considerable aroma challenges. Practices to improve the flavor quality of dairy proteins require a comprehensive understanding of the nature and origins of off-aroma. Unfortunately, existing information from the literature is fragmentary. This review presents sensory lexicons and chemical structures of off-aromas from major dairy ingredients, and it explores their possible precursors and formation mechanisms. It was found that similar chemical structures often contributed to similar off-aroma descriptors. Lipid degradation and Maillard reaction are two primary pathways that commonly cause aroma dissatisfaction. Traditional and novel flavor chemistry tools are usually adopted for off-aroma measurements in dairy ingredients. Strategies for improving aroma quality in dairy derived products include carefully selecting starting materials for formulations, and actively monitoring and optimizing processing and storage conditions.
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28
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Bu P, Jian Z, Koshy J, Shen Y, Yue B, Fan Z. The olfactory subgenome and specific odor recognition in forest musk deer. Anim Genet 2019; 50:358-366. [DOI: 10.1111/age.12796] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2019] [Indexed: 12/27/2022]
Affiliation(s)
- P. Bu
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education) College of Life Sciences Sichuan University Chengdu 610064 China
| | - Z. Jian
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education) College of Life Sciences Sichuan University Chengdu 610064 China
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife College of Life Sciences Sichuan University Chengdu 610064 China
| | - J. Koshy
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education) College of Life Sciences Sichuan University Chengdu 610064 China
| | - Y. Shen
- Sichuan Engineering Research Center for Medicinal Animals Xichang 615000 China
| | - B. Yue
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education) College of Life Sciences Sichuan University Chengdu 610064 China
| | - Z. Fan
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education) College of Life Sciences Sichuan University Chengdu 610064 China
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29
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Tsuzuki S. Higher Straight-Chain Aliphatic Aldehydes: Importance as Odor-Active Volatiles in Human Foods and Issues for Future Research. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:4720-4725. [PMID: 30945546 DOI: 10.1021/acs.jafc.9b01131] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Owing to their apparent lack of health significance, higher straight-chain aliphatic aldehydes, i.e., those having alkyl chains with more than six carbon atoms, have been largely neglected in food and nutraceutical research. However, they are an important class of odor-active volatiles in human foods. Indeed, certain aldehydes, such as hexanal, E-2-nonenal, and E, E-2,4-decadienal, serve as key odorants in a range of our foods and drinks. This perspective describes the significance of higher straight-chain aliphatic aldehydes as food odorants, focusing on several representative ones, and raises the issues regarding these aldehydes to be addressed in the future.
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Affiliation(s)
- Satoshi Tsuzuki
- Division of Food Science and Biotechnology, Graduate School of Agriculture , Kyoto University , Kitashirakawa Oiwake-cho , Sakyo-ku, Kyoto 606-8502 , Japan
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de March CA, Fukutani Y, Vihani A, Kida H, Matsunami H. Real-time In Vitro Monitoring of Odorant Receptor Activation by an Odorant in the Vapor Phase. J Vis Exp 2019. [PMID: 31081824 DOI: 10.3791/59446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Olfactory perception begins with the interaction of odorants with odorant receptors (OR) expressed by olfactory sensory neurons (OSN). Odor recognition follows a combinatorial coding scheme, where one OR can be activated by a set of odorants and one odorant can activate a combination of ORs. Through such combinatorial coding, organisms can detect and discriminate between a myriad of volatile odor molecules. Thus, an odor at a given concentration can be described by an activation pattern of ORs, which is specific to each odor. In that sense, cracking the mechanisms that the brain uses to perceive odor requires the understanding odorant-OR interactions. This is why the olfaction community is committed to "de-orphanize" these receptors. Conventional in vitro systems used to identify odorant-OR interactions have utilized incubating cell media with odorant, which is distinct from the natural detection of odors via vapor odorants dissolution into nasal mucosa before interacting with ORs. Here, we describe a new method that allows for real-time monitoring of OR activation via vapor-phase odorants. Our method relies on measuring cAMP release by luminescence using the Glosensor assay. It bridges current gaps between in vivo and in vitro approaches and provides a basis for a biomimetic volatile chemical sensor.
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Affiliation(s)
- Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center;
| | - Yosuke Fukutani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center; Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology
| | - Aashutosh Vihani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center; Department of Neurobiology, Duke University Medical Center
| | - Hitoshi Kida
- Department of Molecular Genetics and Microbiology, Duke University Medical Center; Department of Mechanical Systems, Engineering, Tokyo University of Agriculture and Technology
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center; Department of Neurobiology, Duke University Medical Center; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology; Duke Institute for Brain Sciences, Duke University;
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Liu MT, Ho J, Liu JK, Purakait R, Morzan UN, Ahmed L, Batista VS, Matsunami H, Ryan K. Carbon chain shape selectivity by the mouse olfactory receptor OR-I7. Org Biomol Chem 2019; 16:2541-2548. [PMID: 29569669 DOI: 10.1039/c8ob00205c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rodent OR-I7 is an olfactory receptor exemplar activated by aliphatic aldehydes such as octanal. Normal alkanals shorter than heptanal bind OR-I7 without activating it and hence function as antagonists in vitro. We report a series of aldehydes designed to probe the structural requirements for aliphatic ligand chains too short to meet the minimum approximate 6.9 Å length requirement for receptor activation. Experiments using recombinant mouse OR-I7 expressed in heterologous cells show that in the context of short aldehyde antagonists, OR-I7 prefers binding aliphatic chains without branches, though a single methyl on carbon-3 is permitted. The receptor can accommodate a surprisingly large number of carbons (e.g. ten in adamantyl) as long as the carbons are part of a conformationally constrained ring system. A rhodopsin-based homology model of mouse OR-I7 docked with the new antagonists suggests that small alkyl branches on the alkyl chain sterically interfere with the hydrophobic residues lining the binding site, but branch carbons can be accommodated when tied back into a compact ring system like the adamantyl and bicyclo[2.2.2]octyl systems.
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Affiliation(s)
- Min Ting Liu
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA. and Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Jianghai Ho
- Department of Molecular Genetics and Microbiology, and Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| | - Jason Karl Liu
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Radhanath Purakait
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA.
| | - Uriel N Morzan
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Lucky Ahmed
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, and Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| | - Kevin Ryan
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA. and Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA and Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
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Na M, Liu MT, Nguyen MQ, Ryan K. Single-Neuron Comparison of the Olfactory Receptor Response to Deuterated and Nondeuterated Odorants. ACS Chem Neurosci 2019; 10:552-562. [PMID: 30343564 DOI: 10.1021/acschemneuro.8b00416] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The mammalian olfactory receptors (ORs) constitute a large subfamily of the Class A G-protein coupled receptors (GPCRs). The molecular details of how these receptors convert odorant chemical information into neural signal are unknown, but are predicted by analogy to other GPCRs to involve stabilization of the activated form of the OR by the odorant. An alternative hypothesis maintains that the vibrational modes of an odorant's bonds constitute the main determinant for OR activation, and that odorants containing deuterium in place of hydrogen should activate different sets of OR family members. Experiments using heterologously expressed ORs have failed to show different responses for deuterated odorants, but experiments in the sensory neuron environment have been lacking. We tested the response to deuterated and nondeuterated versions of p-cymene, 1-octanol, 1-undecanol, and octanal in dissociated mouse olfactory receptor neurons (ORNs) by calcium imaging. In all, we tested 23 812 cells, including a subset expressing recombinant mouse olfactory receptor 2 ( Olfr2/OR-I7 ), and found that nearly all of the 1610 odorant-responding neurons were unable to distinguish the D- and H-odorants. These results support the conclusion that if mammals can perceive deuterated odorants differently, the difference arises from the receptor-independent steps of olfaction. Nevertheless, 0.81% of the responding ORNs responded differently to D- and H-odorants, and those in the octanal experiments responded selectively to H-octanal at concentrations from 3 to 100 μM. The few ORs responding differently to H and D may be hypersensitive to one of the several H/D physicochemical differences, such as the difference in H/D hydrophobicity.
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Affiliation(s)
- Mihwa Na
- Department of Chemistry and Biochemistry, The City College of New York, 160 Convent Avenue, New York, New York 10031, United States
| | - Min Ting Liu
- Department of Chemistry and Biochemistry, The City College of New York, 160 Convent Avenue, New York, New York 10031, United States
| | - Minh Q. Nguyen
- Taste and Smell Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Kevin Ryan
- Department of Chemistry and Biochemistry, The City College of New York, 160 Convent Avenue, New York, New York 10031, United States
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Uytingco CR, Martens JR. Intranasal Delivery of Adenoviral and AAV Vectors for Transduction of the Mammalian Peripheral Olfactory System. Methods Mol Biol 2019; 1950:283-297. [PMID: 30783981 DOI: 10.1007/978-1-4939-9139-6_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Intranasal delivery of solutions is a straightforward methodology for viral vector transduction and gene transfer to the epithelia within the nasal cavity. Beyond the simplicity of the technique, intranasal delivery has demonstrated restricted transduction of the olfactory and respiratory epithelial tissues. Here we outline the procedure of viral vector intranasal delivery in early postnatal and adult mice, as well as adult rats. The procedure allows for robust transduction and ectopic gene delivery that can be used for the visualization of cellular structures, protein distribution, and assessment of viral vector-mediated therapies.
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Affiliation(s)
- Cedric R Uytingco
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.,Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA. .,Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA.
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Abstract
The complexity of the human sense of smell is increasingly reflected in complex and high-dimensional data, which opens opportunities for data-driven approaches that complement hypothesis-driven research. Contemporary developments in computational and data science, with its currently most popular implementation as machine learning, facilitate complex data-driven research approaches. The use of machine learning in human olfactory research included major approaches comprising 1) the study of the physiology of pattern-based odor detection and recognition processes, 2) pattern recognition in olfactory phenotypes, 3) the development of complex disease biomarkers including olfactory features, 4) odor prediction from physico-chemical properties of volatile molecules, and 5) knowledge discovery in publicly available big databases. A limited set of unsupervised and supervised machine-learned methods has been used in these projects, however, the increasing use of contemporary methods of computational science is reflected in a growing number of reports employing machine learning for human olfactory research. This review provides key concepts of machine learning and summarizes current applications on human olfactory data.
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Affiliation(s)
- Jörn Lötsch
- Institute of Clinical Pharmacology, Goethe-University, Frankfurt am Main, Germany
- Fraunhofer Institute of Molecular Biology and Applied Ecology - Project Group Translational Medicine and Pharmacology (IME-TMP), Frankfurt am Main, Germany
| | - Dario Kringel
- Institute of Clinical Pharmacology, Goethe-University, Frankfurt am Main, Germany
| | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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Block E. Molecular Basis of Mammalian Odor Discrimination: A Status Report. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:13346-13366. [PMID: 30453735 DOI: 10.1021/acs.jafc.8b04471] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Humans have 396 unique, intact olfactory receptors (ORs), G-protein coupled receptors (GPCRs) containing receptor-specific binding sites; other mammals have more. Activation of these transmembrane proteins by an odorant initiates a signaling cascade, evoking an action potential leading to perception of a smell. Because the number of distinguishable odorants vastly exceeds the number of ORs, research has focused on mechanisms of recognition and signaling processes for classes of odorants. In this review, selected recent examples will be presented of "deorphaned" mammalian receptors, where the OR ligands (odorants) as well as key aspects of receptor-odorant interactions were identified using odorant-mediated receptor activation data together with site-directed mutagenesis and molecular modeling. Based on cumulative evidence from OR deorphaning and olfactory receptor neuron activation studies, a receptor-ligand docking model rather than an alternative bond vibration model is suggested to best explain the molecular basis of the exquisitely sensitive odor discrimination in mammals.
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Affiliation(s)
- Eric Block
- Department of Chemistry , University at Albany, SUNY , Albany , New York 12222 , United States
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Maßberg D, Hatt H. Human Olfactory Receptors: Novel Cellular Functions Outside of the Nose. Physiol Rev 2018; 98:1739-1763. [PMID: 29897292 DOI: 10.1152/physrev.00013.2017] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Olfactory receptors (ORs) are not exclusively expressed in the olfactory sensory neurons; they are also observed outside of the olfactory system in all other human tissues tested to date, including the testis, lung, intestine, skin, heart, and blood. Within these tissues, certain ORs have been determined to be exclusively expressed in only one tissue, whereas other ORs are more widely distributed in many different tissues throughout the human body. For most of the ectopically expressed ORs, limited data are available for their functional roles. They have been shown to be involved in the modulation of cell-cell recognition, migration, proliferation, the apoptotic cycle, exocytosis, and pathfinding processes. Additionally, there is a growing body of evidence that they have the potential to serve as diagnostic and therapeutic tools, as ORs are highly expressed in different cancer tissues. Interestingly, in addition to the canonical signaling pathways activated by ORs in olfactory sensory neurons, alternative pathways have been demonstrated in nonolfactory tissues. In this review, the existing data concerning the expression, as well as the physiological and pathophysiological functions, of ORs outside of the nose are highlighted to provide insights into future lines of research.
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Affiliation(s)
- Désirée Maßberg
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
| | - Hanns Hatt
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
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Li H, Panwar B, Omenn GS, Guan Y. Accurate prediction of personalized olfactory perception from large-scale chemoinformatic features. Gigascience 2018; 7:4750780. [PMID: 29267859 PMCID: PMC5824779 DOI: 10.1093/gigascience/gix127] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022] Open
Abstract
Background The olfactory stimulus-percept problem has been studied for more than a century, yet it is still hard to precisely predict the odor given the large-scale chemoinformatic features of an odorant molecule. A major challenge is that the perceived qualities vary greatly among individuals due to different genetic and cultural backgrounds. Moreover, the combinatorial interactions between multiple odorant receptors and diverse molecules significantly complicate the olfaction prediction. Many attempts have been made to establish structure-odor relationships for intensity and pleasantness, but no models are available to predict the personalized multi-odor attributes of molecules. In this study, we describe our winning algorithm for predicting individual and population perceptual responses to various odorants in the DREAM Olfaction Prediction Challenge. Results We find that random forest model consisting of multiple decision trees is well suited to this prediction problem, given the large feature spaces and high variability of perceptual ratings among individuals. Integrating both population and individual perceptions into our model effectively reduces the influence of noise and outliers. By analyzing the importance of each chemical feature, we find that a small set of low- and nondegenerative features is sufficient for accurate prediction. Conclusions Our random forest model successfully predicts personalized odor attributes of structurally diverse molecules. This model together with the top discriminative features has the potential to extend our understanding of olfactory perception mechanisms and provide an alternative for rational odorant design.
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Affiliation(s)
- Hongyang Li
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Bharat Panwar
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Gilbert S Omenn
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA.,Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
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Kida H, Fukutani Y, Mainland JD, de March CA, Vihani A, Li YR, Chi Q, Toyama A, Liu L, Kameda M, Yohda M, Matsunami H. Vapor detection and discrimination with a panel of odorant receptors. Nat Commun 2018; 9:4556. [PMID: 30385742 PMCID: PMC6212438 DOI: 10.1038/s41467-018-06806-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 09/04/2018] [Indexed: 12/29/2022] Open
Abstract
Olfactory systems have evolved the extraordinary capability to detect and discriminate volatile odorous molecules (odorants) in the environment. Fundamentally, this process relies on the interaction of odorants and their cognate olfactory receptors (ORs) encoded in the genome. Here, we conducted a cell-based screen using over 800 mouse ORs against seven odorants, resulting in the identification of a set of high-affinity and/or broadly-tuned ORs. We then test whether heterologously expressed ORs respond to odors presented in vapor phase by individually expressing 31 ORs to measure cAMP responses against vapor phase odor stimulation. Comparison of response profiles demonstrates this platform is capable of discriminating between structural analogs. Lastly, co-expression of carboxyl esterase Ces1d expressed in olfactory mucosa resulted in marked changes in activation of specific odorant-OR combinations. Altogether, these results establish a cell-based volatile odor detection and discrimination platform and form the basis for an OR-based volatile odor sensor. Biomimetic “noses” have been proposed to replace trained animals for chemical detection. Here the authors select 31 mouse olfactory receptors (ORs), based on a large cell-based screen of >800 ORs against seven chemicals, to build an OR-based sensor able to discriminate structurally similar compounds.
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Affiliation(s)
- Hitoshi Kida
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Yosuke Fukutani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Joel D Mainland
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Monell Chemical Senses Center, Philadelphia, PA, 19104, USA.,Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Aashutosh Vihani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Neurobiology, Neurobiology graduate program, Duke University Medical Center, Durham, NC, 27710, USA
| | - Yun Rose Li
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - Qiuyi Chi
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Akemi Toyama
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Linda Liu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Masaharu Kameda
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA. .,Department of Neurobiology, Neurobiology graduate program, Duke University Medical Center, Durham, NC, 27710, USA. .,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan. .,Duke Institute for Brain Sciences, Duke University, Durham, NC, 27710, USA.
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Muttray A, Gosepath J, Schmall F, Brieger J, Mayer-Popken O, Melia M, Letzel S. An acute exposure to ozone impairs human olfactory functioning. ENVIRONMENTAL RESEARCH 2018; 167:42-50. [PMID: 30007872 DOI: 10.1016/j.envres.2018.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 06/11/2018] [Accepted: 07/03/2018] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Ozone is a ubiquitous and irritant gas. We questioned whether an acute exposure to 0.2 ppm ozone impaired olfactory functioning. METHODS Healthy, normosmic subjects were exposed according to a parallel group design either to 0.2 ppm ozone (n = 15) or to sham (n = 13) in an exposure chamber for two hours. Possible irritating effects were assessed by questionnaire (range 0-5). The detection threshold of n-butanol was measured with the Sniffin' Sticks test before and after exposure. Olfactory thresholds were logarithmized and a two-way analysis of variance (ANOVA) with repeated measurements was carried out to test the effects of exposure (ozone vs. sham) and time (before vs. after exposure). Additionally, nasal secretions were taken at a preliminary examination and after exposure to determine interleukins 1ß and 8. RESULTS No irritating effects to the upper airways were observed. In the ozone group, the median score for cough increased from 0 to 2 at the end of exposure (sham group 0 and 0, respectively, p < 0.001). The ANOVA showed a main effect for ozone exposure (F (1, 26) = 27.6, p = 0.0002), indicating higher olfactory thresholds in the ozone group. Concentrations of interleukins in nasal secretions did not increase following ozone exposure. CONCLUSIONS This study shows a clear impairment of olfactory functioning following an acute exposure to 0.2 ppm ozone.
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Affiliation(s)
- Axel Muttray
- Institute of Occupational, Social and Environmental Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany.
| | - Jan Gosepath
- Department of Otolaryngology of the University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Florian Schmall
- Institute of Occupational, Social and Environmental Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany; Department of Otolaryngology of the University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Jürgen Brieger
- Department of Otolaryngology of the University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Otfried Mayer-Popken
- Institute of Occupational, Social and Environmental Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Michael Melia
- Institute of Occupational, Social and Environmental Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Stephan Letzel
- Institute of Occupational, Social and Environmental Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
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Wu Y, Ma L, Duyck K, Long CC, Moran A, Scheerer H, Blanck J, Peak A, Box A, Perera A, Yu CR. A Population of Navigator Neurons Is Essential for Olfactory Map Formation during the Critical Period. Neuron 2018; 100:1066-1082.e6. [PMID: 30482691 DOI: 10.1016/j.neuron.2018.09.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/10/2018] [Accepted: 09/27/2018] [Indexed: 11/29/2022]
Abstract
In the developing brain, heightened plasticity during the critical period enables the proper formation of neural circuits. Here, we identify the "navigator" neurons, a group of perinatally born olfactory sensory neurons, as playing an essential role in establishing the olfactory map during the critical period. The navigator axons project circuitously in the olfactory bulb and traverse multiple glomeruli before terminating in perspective glomeruli. These neurons undergo a phase of exuberant axon growth and exhibit a shortened lifespan. Single-cell transcriptome analyses reveal distinct molecular signatures for the navigators. Extending their lifespan prolongs the period of exuberant growth and perturbs axon convergence. Conversely, a genetic ablation experiment indicates that, despite postnatal neurogenesis, only the navigators are endowed with the ability to establish a convergent map. The presence and the proper removal of the navigator neurons are both required to establish tight axon convergence into the glomeruli.
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Affiliation(s)
- Yunming Wu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Limei Ma
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Kyle Duyck
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Carter C Long
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Andrea Moran
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Hayley Scheerer
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Jillian Blanck
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Allison Peak
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Andrew Box
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Anoja Perera
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - C Ron Yu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
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Shang M, Xing J. Blocking of Dendrodendritic Inhibition Unleashes Widely Spread Lateral Propagation of Odor-evoked Activity in the Mouse Olfactory Bulb. Neuroscience 2018; 391:50-59. [PMID: 30208337 DOI: 10.1016/j.neuroscience.2018.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 09/01/2018] [Accepted: 09/03/2018] [Indexed: 01/27/2023]
Abstract
The olfactory circuitry in mice involves a well-characterized, vertical receptor type-specific organization, but the localized inhibitory effect from granule cells on action potentials that propagate laterally in secondary dendrites of mitral cell remains open to debate. To understand the functional dynamics of the lateral (horizontal) circuits, we analyzed odor-induced signaling using transgenic mice expressing a genetically encoded Ca2+ indicator specifically in mitral/tufted and some juxtaglomerular cells. Optical imaging of the dorsal olfactory bulb (dOB) revealed specific patterns of glomerular activation in response to odor presentation or direct electric stimulation of the olfactory nerve (ON). Application of a mixture of ionotropic and metabotropic glutamate receptor antagonists onto the exposed dOB completely abolished the responses to direct stimulation of the ON as well as discrete odor-evoked glomerular responses patterns, while a spatially more widespread response component increased and expanded into previously nonresponsive regions. To test whether the widespread odor response component represented signal propagation along mitral cell secondary dendrites, an NMDA receptor antagonist alone was applied to the dOB and was found to also increase and expand odor-evoked response patterns. Finally, with dOB excitatory synaptic transmission completely blocked, application of 1 mM muscimol (a GABAA receptor agonist) to a circumscribed volume in the deep external plexiform layer (EPL) induced an odor non-responsive area. These results indicate that odor stimulation can activate olfactory reciprocal synapses and control lateral interactions among olfactory glomerular modules along a wide range of mitral cell secondary dendrites by modulating the inhibitory effect from granule cells.
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Affiliation(s)
- Mengjuan Shang
- Department of Radiation Medicine, Faculty of Preventive Medicine, Airforce Medical University, 169(#) ChangLe West Road, Xi'an 710032, China
| | - Junling Xing
- Department of Radiation Biology, Faculty of Preventive Medicine, Airforce Medical University, 169(#) ChangLe West Road, Xi'an 710032, China; Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06520-8001, USA.
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42
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Hu R, Zhang J, Luo M, Hu J. Response Patterns of GABAergic Neurons in the Anterior Piriform Cortex of Awake Mice. Cereb Cortex 2018; 27:3110-3124. [PMID: 27252353 DOI: 10.1093/cercor/bhw175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Local inhibition by γ-amino butyric acid (GABA)-containing neurons is of vital importance for the operation of sensory cortices. However, the physiological response patterns of cortical GABAergic neurons are poorly understood, especially in the awake condition. Here, we utilized the recently developed optical tagging technique to specifically record GABAergic neurons in the anterior piriform cortex (aPC) in awake mice. The identified aPC GABAergic neurons were stimulated with robotic delivery of 32 distinct odorants, which covered a broad range of functional groups. We found that aPC GABAergic neurons could be divided into 4 types based on their response patterns. Type I, type II, and type III neurons displayed broad excitatory responses to test odorants with different dynamics. Type I neurons were constantly activated during odorant stimulation, whereas type II neurons were only transiently activated at the onset of odorant delivery. In addition, type III neurons displayed transient excitatory responses both at the onset and termination of odorant presentation. Interestingly, type IV neurons were broadly inhibited by most of the odorants. Taken together, aPC GABAergic neurons adopt different strategies to affect the cortical circuitry. Our results will allow for better understanding of the role of cortical GABAergic interneurons in sensory information processing.
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Affiliation(s)
- Rongfeng Hu
- Center for Neuron and Disease, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Juen Zhang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Minmin Luo
- National Institute of Biological Sciences, Beijing 102206, China
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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Armelin-Correa LM, Malnic B. Combining In Vivo and In Vitro Approaches To Identify Human Odorant Receptors Responsive to Food Odorants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:2214-2218. [PMID: 28054485 DOI: 10.1021/acs.jafc.6b04998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Olfactory perception plays an important role in food flavor. Humans have around 400 odorant receptors (ORs), which can be activated by an enormous number of odorants in a combinatorial fashion. To date, only a few odorant receptors have been linked to their respective odorants, due to the difficulties in expressing these receptor proteins in heterologous cell systems. In vivo approaches allow for the analysis of odorant-receptor interactions in their native environment and have the advantage that the complete OR repertoire is simultaneously tested. Once mouse odorant-receptor pairs are defined, one can search for the corresponding human orthologues, which can be validated against the odorants in heterologous cells. Thus, the combination of in vivo and in vitro methods should contribute to the identification of human ORs that recognize odorants of interest, such as key food odorants.
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Affiliation(s)
- Lucia M Armelin-Correa
- Department of Biological Sciences, Diadema Campus , Federal University of São Paulo , São Paulo , Brazil
| | - Bettina Malnic
- Department of Biochemistry , University of São Paulo , São Paulo , Brazil
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Chronic perinatal odour exposure with heptaldehyde affects odour sensitivity and olfactory system homeostasis in preweaning mice. Behav Brain Res 2018. [PMID: 29526787 DOI: 10.1016/j.bbr.2018.02.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exposure to specific odorants in the womb during pregnancy or in the milk during early nursing is known to impact morpho-functional development of the olfactory circuitry of pups. This can be associated with a modification in olfactory sensitivity and behavioural olfactory-based preferences to the perinatally encountered odorants measured at birth, weaning or adult stage. Effects depend on a multitude of factors, such as odorant type, concentration, administration mode and frequency, as well as timing and mice strain. Here, we examined the effect of perinatal exposure to heptaldehyde on the neuro-anatomical development of the olfactory receptor Olfr2 circuitry, olfactory sensitivity and odour preferences of preweaning pups using mI7-IRES-tau-green fluorescent protein mice. We found that perinatal odour exposure through the feed of the dam reduces the response to heptaldehyde and modulates transcript levels of neuronal transduction proteins in the olfactory epithelium of the pups. Furthermore, the number of I7 glomeruli related to Olfr2-expressing OSN is altered in a way similar to that seen with restricted post-natal exposure, in an age-dependent way. These variations are associated with a modification of olfactory behaviours associated with early post-natal odour preferences at weaning.
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45
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Poivet E, Tahirova N, Peterlin Z, Xu L, Zou DJ, Acree T, Firestein S. Functional odor classification through a medicinal chemistry approach. SCIENCE ADVANCES 2018; 4:eaao6086. [PMID: 29487905 PMCID: PMC5817921 DOI: 10.1126/sciadv.aao6086] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 01/11/2018] [Indexed: 05/19/2023]
Abstract
Crucial for any hypothesis about odor coding is the classification and prediction of sensory qualities in chemical compounds. The relationship between perceptual quality and molecular structure has occupied olfactory scientists throughout the 20th century, but details of the mechanism remain elusive. Odor molecules are typically organic compounds of low molecular weight that may be aliphatic or aromatic, may be saturated or unsaturated, and may have diverse functional polar groups. However, many molecules conforming to these characteristics are odorless. One approach recently used to solve this problem was to apply machine learning strategies to a large set of odors and human classifiers in an attempt to find common and unique chemical features that would predict a chemical's odor. We use an alternative method that relies more on the biological responses of olfactory sensory neurons and then applies the principles of medicinal chemistry, a technique widely used in drug discovery. We demonstrate the effectiveness of this strategy through a classification for esters, an important odorant for the creation of flavor in wine. Our findings indicate that computational approaches that do not account for biological responses will be plagued by both false positives and false negatives and fail to provide meaningful mechanistic data. However, the two approaches used in tandem could resolve many of the paradoxes in odor perception.
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Affiliation(s)
- Erwan Poivet
- Neuroscience Institute, NYU Langone Medical Center, NY 10016, USA
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Narmin Tahirova
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Zita Peterlin
- Corporate Research and Development, Firmenich Incorporated, Plainsboro, NJ 08536, USA
| | - Lu Xu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Dong-Jing Zou
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Terry Acree
- Department of Food Science, Cornell University, Ithaca, NY 14850, USA
| | - Stuart Firestein
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
- Corresponding author.
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Kojima H, Araki S, Kaneda H, Takashio M. Application of a New Electronic Nose with Fingerprint Mass Spectrometry to Brewing. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-63-0151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Hidetoshi Kojima
- Frontier Laboratories of Value Creation, Sapporo Breweries, Ltd., 10 Okatohme, Yaizu, Shizuoka, 425-0013 Japan
| | - Shigeki Araki
- Frontier Laboratories of Value Creation, Sapporo Breweries, Ltd., 10 Okatohme, Yaizu, Shizuoka, 425-0013 Japan
| | - Hirotaka Kaneda
- Frontier Laboratories of Value Creation, Sapporo Breweries, Ltd., 10 Okatohme, Yaizu, Shizuoka, 425-0013 Japan
| | - Masachika Takashio
- Frontier Laboratories of Value Creation, Sapporo Breweries, Ltd., 10 Okatohme, Yaizu, Shizuoka, 425-0013 Japan
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In Vivo Electrophysiological Recordings of Olfactory Receptor Neuron Units and Electro-olfactograms in Anesthetized Rats. Methods Mol Biol 2018; 1820:123-135. [PMID: 29884942 DOI: 10.1007/978-1-4939-8609-5_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In vivo recordings of single olfactory receptor neurons and electro-olfactograms (EOG, field potentials from the olfactory mucosa) provide insights into the olfactory processing properties of the olfactory peripheral stage. Because the olfactory receptor neurons are very small electrical generators, it is not easy to unitarily record them in amphibians, reptilians, and fishes. In mammals such recordings are even more difficult to obtain: primarily due to the anatomical configuration in complex turbinates of the olfactory mucosa and its propensity to hemorrhage during surgery; secondarily due to the fact that olfactory receptor neurons are held in closely packed clusters in the olfactory mucosa and are difficult to isolate, from the electrophysiological recording point of view. Here we describe the material and methods we used in vivo, in rats-occasionally, also tested in mice-to get simultaneously receptor neuron single and electro-olfactogram recordings, from septal region or the endoturbinate II, in freely breathing or tracheotomized anesthetized animals. Recording EOG in parallel with receptor neuron units provide, by reflecting the population response to the olfactory stimulus, the continuous assurance of the good physiological state and reactivity of the olfactory epithelium. This configuration will ensure that when a single ORN does not respond to a stimulus it resulted from its qualitative selectivity and not from the olfactory mucosa damaged status.
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Applications and Advances in Bioelectronic Noses for Odour Sensing. SENSORS 2018; 18:s18010103. [PMID: 29301263 PMCID: PMC5795383 DOI: 10.3390/s18010103] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/22/2017] [Accepted: 11/25/2017] [Indexed: 01/15/2023]
Abstract
A bioelectronic nose, an intelligent chemical sensor array system coupled with bio-receptors to identify gases and vapours, resembles mammalian olfaction by which many vertebrates can sniff out volatile organic compounds (VOCs) sensitively and specifically even at very low concentrations. Olfaction is undertaken by the olfactory system, which detects odorants that are inhaled through the nose where they come into contact with the olfactory epithelium containing olfactory receptors (ORs). Because of its ability to mimic biological olfaction, a bio-inspired electronic nose has been used to detect a variety of important compounds in complex environments. Recently, biosensor systems have been introduced that combine nanoelectronic technology and olfactory receptors themselves as a source of capturing elements for biosensing. In this article, we will present the latest advances in bioelectronic nose technology mimicking the olfactory system, including biological recognition elements, emerging detection systems, production and immobilization of sensing elements on sensor surface, and applications of bioelectronic noses. Furthermore, current research trends and future challenges in this field will be discussed.
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Noe F, Geithe C, Fiedler J, Krautwurst D. A bi-functional IL-6-HaloTag ® as a tool to measure the cell-surface expression of recombinant odorant receptors and to facilitate their activity quantification. J Biol Methods 2017; 4:e82. [PMID: 31453236 PMCID: PMC6706140 DOI: 10.14440/jbm.2017.207] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/28/2017] [Accepted: 08/25/2017] [Indexed: 11/23/2022] Open
Abstract
The functional cell surface expression of recombinant odorant receptors typically has been investigated by expressing N-terminally extended, "tagged" receptors in test cell systems, using antibody-based immunocytochemistry or flow cytometry, and by measuring odorant/receptor-induced cAMP signaling, mostly by an odorant/receptor-induced and cAMP signaling-dependent transcriptional activation of a luciferase-based luminescence assay. In the present protocol, we explain a method to measure the cell-surface expression and signaling of recombinant odorant receptors carrying a bi-functional, N-terminal 'IL-6-HaloTag®'. IL-6, being a secreted cytokine, facilitates functional cell surface expression of recombinant HaloTag®-odorant receptors, and the HaloTag® protein serves as a highly specific acceptor for cell-impermeant or cell-permeant, fluorophore-coupled ligands, which enable the quantification of odorant receptor expression by antibody-independent, chemical live-cell staining and flow cytometry. Here, we describe how to measure the cell surface expression of recombinant IL-6-HaloTag®-odorant receptors in HEK-293 cells or NxG 108CC15 cells, by live-cell staining and flow cytometry, and how to measure an odorant-induced activation of these receptors by the fast, real-time, luminescence-based GloSensor® cAMP assay.
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Affiliation(s)
| | | | | | - Dietmar Krautwurst
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, D-85354 Freising, Germany
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50
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Activity Patterns Elicited by Airflow in the Olfactory Bulb and Their Possible Functions. J Neurosci 2017; 37:10700-10711. [PMID: 28972124 DOI: 10.1523/jneurosci.2210-17.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/23/2017] [Accepted: 09/28/2017] [Indexed: 12/29/2022] Open
Abstract
Olfactory sensory neurons (OSNs) can sense both odorants and airflows. In the olfactory bulb (OB), the coding of odor information has been well studied, but the coding of mechanical stimulation is rarely investigated. Unlike odor-sensing functions of OSNs, the airflow-sensing functions of OSNs are also largely unknown. Here, the activity patterns elicited by mechanical airflow in male rat OBs were mapped using fMRI and correlated with local field potential recordings. In an attempt to reveal possible functions of airflow sensing, the relationship between airflow patterns and physiological parameters was also examined. We found the following: (1) the activity pattern in the OB evoked by airflow in the nasal cavity was more broadly distributed than patterns evoked by odors; (2) the pattern intensity increases with total airflow, while the pattern topography with total airflow remains almost unchanged; and (3) the heart rate, spontaneous respiratory rate, and electroencephalograph power in the β band decreased with regular mechanical airflow in the nasal cavity. The mapping results provide evidence that the signals elicited by mechanical airflow in OSNs are transmitted to the OB, and that the OB has the potential to code and process mechanical information. Our functional data indicate that airflow rhythm in the olfactory system can regulate the physiological and brain states, providing an explanation for the effects of breath control in meditation, yoga, and Taoism practices.SIGNIFICANCE STATEMENT Presentation of odor information in the olfactory bulb has been well studied, but studies about breathing features are rare. Here, using blood oxygen level-dependent functional MRI for the first time in such an investigation, we explored the global activity patterns in the rat olfactory bulb elicited by airflow in the nasal cavity. We found that the activity pattern elicited by airflow is broadly distributed, with increasing pattern intensity and similar topography under increasing total airflow. Further, heart rate, spontaneous respiratory rate in the lung, and electroencephalograph power in the β band decreased with regular airflow in the nasal cavity. Our study provides further understanding of the airflow map in the olfactory bulb in vivo, and evidence for the possible mechanosensitivity functions of olfactory sensory neurons.
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