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Abstract
Internal organs, including the airway, are innervated by neurons of the autonomic and sensory nervous systems. The airway-innervating sensory neurons primarily originate from the vagus nerve, whose cell bodies are found, in rodents, in the jugular and nodose ganglia complex (JNC). About half of these sensory neurons expressed the heat-sensing ion channel TRPV1 and evolved to limit tissue damage by detecting chemical, mechanical, or thermal threats and to initiate protective airway reflexes such as coughing and bronchoconstriction. They also help monitor the host homeostasis by sensing nutrients, pressure, and O2 levels and help mount airway defenses by controlling immune and goblet cell activity. To better appreciate the scope of the physiological role and pathological contributions of these neurons, we will review gain and loss-of-function approaches geared at controlling the activity of these neurons. We will also present a method to study transcriptomic changes in airway-innervating neurons and a co-culture approach designed to understand how nociceptors modulate immune responses.
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Affiliation(s)
- Jo-Chiao Wang
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, Canada
| | - Theo Crosson
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, Canada
| | - Sebastien Talbot
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, Canada.
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2
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Drake MG, Cook M, Fryer AD, Jacoby DB, Scott GD. Airway Sensory Nerve Plasticity in Asthma and Chronic Cough. Front Physiol 2021; 12:720538. [PMID: 34557110 PMCID: PMC8452850 DOI: 10.3389/fphys.2021.720538] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/02/2021] [Indexed: 01/21/2023] Open
Abstract
Airway sensory nerves detect a wide variety of chemical and mechanical stimuli, and relay signals to circuits within the brainstem that regulate breathing, cough, and bronchoconstriction. Recent advances in histological methods, single cell PCR analysis and transgenic mouse models have illuminated a remarkable degree of sensory nerve heterogeneity and have enabled an unprecedented ability to test the functional role of specific neuronal populations in healthy and diseased lungs. This review focuses on how neuronal plasticity contributes to development of two of the most common airway diseases, asthma and chronic cough, and discusses the therapeutic implications of emerging treatments that target airway sensory nerves.
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Affiliation(s)
- Matthew G. Drake
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Madeline Cook
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Allison D. Fryer
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - David B. Jacoby
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Gregory D. Scott
- Department of Pathology, Oregon Health and Science University, Portland, OR, United States
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3
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Tauber M, Wang F, Kim B, Gaudenzio N. Bidirectional sensory neuron-immune interactions: a new vision in the understanding of allergic inflammation. Curr Opin Immunol 2021; 72:79-86. [PMID: 33873125 DOI: 10.1016/j.coi.2021.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
Peripheral neurons (including sensory neurons) are ubiquitously distributed in all tissues, particularly at the interface with the environment. The primary function of sensory neurons is the transmission of sensations of temperature, pain and itch to elicit appropriate behavioral responses. More recently, sensory neurons have emerged as potent regulators of type 2 immune responses and allergic inflammation. There is increasing evidence showing that neurons can express receptors previously thought to be restricted to the immune compartment. In addition, certain subtypes of immune cells (e.g. mast cells, ILC2s or macrophages) also express specific neuroreceptors that provide them with the capacity to integrate neuron-derived signals and modulate their activation status during the development of allergic inflammation.
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Affiliation(s)
- Marie Tauber
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291 CNRS UMR5051, University of Toulouse III, Toulouse, France; Department of Dermatology, Toulouse University Hospital, France
| | - Fang Wang
- Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Brian Kim
- Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Nicolas Gaudenzio
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291 CNRS UMR5051, University of Toulouse III, Toulouse, France.
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4
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Pincus AB, Fryer AD, Jacoby DB. Mini review: Neural mechanisms underlying airway hyperresponsiveness. Neurosci Lett 2021; 751:135795. [PMID: 33667601 DOI: 10.1016/j.neulet.2021.135795] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 12/25/2022]
Abstract
Neural changes underly hyperresponsiveness in asthma and other airway diseases. Afferent sensory nerves, nerves within the brainstem, and efferent parasympathetic nerves all contribute to airway hyperresponsiveness. Inflammation plays a critical role in these nerve changes. Chronic inflammation and pre-natal exposures lead to increased airway innervation and structural changes. Acute inflammation leads to shifts in neurotransmitter expression of afferent nerves and dysfunction of M2 muscarinic receptors on efferent nerve endings. Eosinophils and macrophages drive these changes through release of inflammatory mediators. Novel tools, including optogenetics, two photon microscopy, and optical clearing and whole mount microscopy, allow for improved studies of the structure and function of airway nerves and airway hyperresponsiveness.
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Affiliation(s)
- Alexandra B Pincus
- Oregon Health and Science University, 3181 SW Sam Jackson Park Road, BRB 440, Portland, OR, 97239, USA.
| | - Allison D Fryer
- Oregon Health and Science University, 3181 SW Sam Jackson Park Road, BRB 440, Portland, OR, 97239, USA
| | - David B Jacoby
- Oregon Health and Science University, 3181 SW Sam Jackson Park Road, BRB 440, Portland, OR, 97239, USA
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5
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Zalecki M, Juranek J, Pidsudko Z, Mogielnicka-Brzozowska M, Kaleczyc J, Franke-Radowiecka A. Inferior vagal ganglion galaninergic response to gastric ulcers. PLoS One 2020; 15:e0242746. [PMID: 33227035 PMCID: PMC7682887 DOI: 10.1371/journal.pone.0242746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 11/06/2020] [Indexed: 01/17/2023] Open
Abstract
Galanin is a neuropeptide widely expressed in central and peripheral nerves and is known to be engaged in neuronal responses to pathological changes. Stomach ulcerations are one of the most common gastrointestinal disorders. Impaired stomach function in peptic ulcer disease suggests changes in autonomic nerve reflexes controlled by the inferior vagal ganglion, resulting in stomach dysfunction. In this paper, changes in the galaninergic response of inferior vagal neurons to gastric ulceration in a pig model of the disease were analyzed based on the authors' previous studies. The study was performed on 24 animals (12 control and 12 experimental). Gastric ulcers were induced by submucosal injections of 40% acetic acid solution into stomach submucosa and bilateral inferior vagal ganglia were collected one week afterwards. The number of galanin-immunoreactive perikarya in each ganglion was counted to determine fold-changes between both groups of animals and Q-PCR was applied to verify the changes in relative expression level of mRNA encoding both galanin and its receptor subtypes: GalR1, GalR2, GalR3. The results revealed a 2.72-fold increase in the number of galanin-immunoreactive perikarya compared with the controls. Q-PCR revealed that all studied genes were expressed in examined ganglia in both groups of animals. Statistical analysis revealed a 4.63-fold increase in galanin and a 1.45-fold increase in GalR3 mRNA as compared with the controls. No differences were observed between the groups for GalR1 or GalR2. The current study confirmed changes in the galaninergic inferior vagal ganglion response to stomach ulcerations and demonstrated, for the first time, the expression of mRNA encoding all galanin receptor subtypes in the porcine inferior vagal ganglia.
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Affiliation(s)
- Michal Zalecki
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
- * E-mail:
| | - Judyta Juranek
- Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Zenon Pidsudko
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Marzena Mogielnicka-Brzozowska
- Department of Animal Biochemistry and Biotechnology, Faculty of Animal Bioengineering, University of Warmia and Mazury, Olsztyn, Poland
| | - Jerzy Kaleczyc
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Amelia Franke-Radowiecka
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
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6
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Gharbavi M, Sharafi A, Ghanbarzadeh S. Mesenchymal Stem Cells: A New Generation of Therapeutic Agents as Vehicles in Gene Therapy. Curr Gene Ther 2020; 20:269-284. [PMID: 32515309 DOI: 10.2174/1566523220666200607190339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 12/26/2022]
Abstract
In recent years, mesenchymal stem cells (MSCs) as a new tool for therapeutic gene delivery in clinics have attracted much attention. Their advantages cover longer lifespan, better isolation, and higher transfection efficiency and proliferation rate. MSCs are the preferred approach for cell-based therapies because of their in vitro self-renewal capacity, migrating especially to tumor tissues, as well as anti-inflammatory and immunomodulatory properties. Therefore, they have considerable efficiency in genetic engineering for future clinical applications in cancer gene therapy and other diseases. For improving therapeutic efficiency, targeted therapy of cancers can be achieved through the sustained release of therapeutic agents and functional gene expression induction to the intended tissues. The development of a new vector in gene therapy can improve the durability of a transgene expression. Also, the safety of the vector, if administered systemically, may resolve several problems, such as durability of expression and the host immune response. Currently, MSCs are prominent candidates as cell vehicles for both preclinical and clinical trials due to the secretion of therapeutic agents in several cancers. In the present study, we discuss the status of gene therapy in both viral and non-viral vectors along with their limitations. Throughout this study, the use of several nano-carriers for gene therapy is also investigated. Finally, we critically discuss the promising advantages of MSCs in targeted gene delivery, tumor inhibition and their utilization as the gene carriers in clinical situations.
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Affiliation(s)
- Mahmoud Gharbavi
- Department of Pharmaceutical Biomaterials, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan,
Iran,Cancer Gene Therapy Research Center, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan,
Iran,Zanjan Applied Pharmacology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Ali Sharafi
- Zanjan Applied Pharmacology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran,Zanjan Pharmaceutical Biotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Saeed Ghanbarzadeh
- Cancer Gene Therapy Research Center, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan,
Iran,Zanjan Pharmaceutical Nanotechnology Research Center and Department of Pharmaceutics, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran
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7
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Pecova T, Kocan I, Vysehradsky R, Pecova R. Itch and Cough - Similar Role of Sensory Nerves in Their Pathogenesis. Physiol Res 2020; 69:S43-S54. [PMID: 32228011 DOI: 10.33549/physiolres.934403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Itch is the most common chief complaint in patients visiting dermatology clinics and is analogous to cough and also sneeze of the lower and upper respiratory tract, all three of which are host actions trying to clear noxious stimuli. The pathomechanisms of these symptoms are not completely determined. The itch can originate from a variety of etiologies. Itch originates following the activation of peripheral sensory nerve endings following damage or exposure to inflammatory mediators. More than one sensory nerve subtype is thought to subservepruriceptive itch which includes both unmyelinated C-fibers and thinly myelinated Adelta nerve fibers. There are a lot of mediators capable of stimulating these afferent nerves leading to itch. Cough and itch pathways are mediated by small-diameter sensory fibers. These cough and itch sensory fibers release neuropeptides upon activation, which leads to inflammation of the nerves. The inflammation is involved in the development of chronic conditions of itch and cough. The aim of this review is to point out the role of sensory nerves in the pathogenesis of cough and itching. The common aspects of itch and cough could lead to new thoughts and perspectives in both fields.
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Affiliation(s)
- T Pecova
- Clinic of Dermatovenerology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital in Martin, Martin, Slovak
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8
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Foucaud L, Demoulin B, Leblanc AL, Ioan I, Schweitzer C, Demoulin-Alexikova S. Modulation of protective reflex cough by acute immune driven inflammation of lower airways in anesthetized rabbits. PLoS One 2019; 14:e0226442. [PMID: 31887143 PMCID: PMC6936810 DOI: 10.1371/journal.pone.0226442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/26/2019] [Indexed: 11/19/2022] Open
Abstract
Chronic irritating cough in patients with allergic disorders may reflect behavioral or reflex response that is inappropriately matched to the stimulus present in the respiratory tract. Such dysregulated response is likely caused by sensory nerve damage driven by allergic mediators leading to cough hypersensitivity. Some indirect findings suggest that even acid-sensitive, capsaicin-insensitive A-δ fibers called “cough receptors” that are likely responsible for protective reflex cough may be modulated through immune driven inflammation. The aim of this study was to find out whether protective reflex cough is altered during acute allergic airway inflammation in rabbits sensitized to ovalbumin. In order to evaluate the effect of such inflammation exclusively on protective reflex cough, C-fiber mediated cough was silenced using general anesthesia. Cough provocation using citric acid inhalation and mechanical stimulation of trachea was realized in 16 ovalbumin (OVA) sensitized, anesthetized and tracheotomised rabbits 24h after OVA (OVA group, n = 9) or saline challenge (control group, n = 7). Number of coughs provoked by citric acid inhalation did not differ between OVA and control group (12,2 ±6,1 vs. 17,9 ± 6,9; p = 0.5). Allergic airway inflammation induced significant modulation of cough threshold (CT) to mechanical stimulus. Mechanically induced cough reflex in OVA group was either up-regulated (subgroup named “responders” CT: 50 msec (50–50); n = 5 p = 0.003) or down-regulated (subgroup named “non responders”, CT: 1200 msec (1200–1200); n = 4 p = 0.001) when compared to control group (CT: 150 msec (75–525)). These results advocate that allergen may induce longer lasting changes of reflex cough pathway, leading to its up- or down-regulation. These findings may be of interest as they suggest that effective therapies for chronic cough in allergic patients should target sensitized component of both, reflex and behavioral cough.
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Affiliation(s)
- Laurent Foucaud
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
| | - Bruno Demoulin
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
| | - Anne-Laure Leblanc
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
| | - Iulia Ioan
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
- Department of Pediatric Functional Testing, Hôpital d’Enfants, CHRU de Nancy, Vandoeuvre-Les-Nancy, France
| | - Cyril Schweitzer
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
- Department of Pediatric Functional Testing, Hôpital d’Enfants, CHRU de Nancy, Vandoeuvre-Les-Nancy, France
| | - Silvia Demoulin-Alexikova
- Research Unit EA 3450 DevAH—Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandœuvre-Lès-Nancy, France
- Department of Pediatric Functional Testing, Hôpital d’Enfants, CHRU de Nancy, Vandoeuvre-Les-Nancy, France
- * E-mail:
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9
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Kytikova OY, Novgorodtseva TP, Antonyuk MV, Gvozdenko TA. The role of regulatory neuropeptides and neurotrophic factors in asthma pathophysiology. RUSSIAN OPEN MEDICAL JOURNAL 2019. [DOI: 10.15275/rusomj.2019.0402] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In the last decade, the attention of scientists in the field of biomedicine is focused on studying the relationship between the immunological and neurogenic components of the inflammatory response and their contribution to the pathophysiology of allergic inflammation in asthma. The review is devoted to detailing the mechanism of neurogenic inflammation involving regulatory neuropeptides (substance P, vasoactive intestinal peptide, calcitonin gene-related peptide) in the pathogenesis of bronchial hyperreactivity in asthma. The role of neurotrophic growth factors (nerve growth factor, brain-derived neurotrophic factor) in the regulation of remodeling of bronchi in asthma has been analyzed. The study of neuroimmune mechanisms in the pathophysiology of asthma will it possible to find new therapeutic targets in this research area.
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Affiliation(s)
- Oxana Yu. Kytikova
- Scientific Research Institute of Medical Climatology and Rehabilitation Treatment
| | | | - Marina V. Antonyuk
- Scientific Research Institute of Medical Climatology and Rehabilitation Treatment
| | - Tatyana A. Gvozdenko
- Scientific Research Institute of Medical Climatology and Rehabilitation Treatment
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10
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Ren X, Dong F, Zhuang Y, Wang Y, Ma W. Effect of neuromedin U on allergic airway inflammation in an asthma model. Exp Ther Med 2019; 19:809-816. [PMID: 32010240 PMCID: PMC6966147 DOI: 10.3892/etm.2019.8283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022] Open
Abstract
Asthma is a major inflammatory airway disease with high incidence and mortality rates. The Global Initiative for Asthma released a report called ‘The Global Burden of Asthma’ in 2004. However, the specific pathogenesis of asthma remains unclear. An increasing number of studies have demonstrated that neuromedin U (NMU) plays a pleiotropic role in the pathogenesis of asthma. NMU is a highly structurally conserved neuropeptide that was first purified from porcine spinal cord and named for its contractile effect on the rat uterus. NMU amplifies type 2 innate lymphoid cell (ILC2)-driven allergic lung inflammation. The NMU receptors (NMURs), designated as NMUR1 and NMUR2, belong to the G protein-coupled receptor family. NMUR1 has also been found in immune cells, including ILC2s, mast cells and eosinophils. In view of the important roles of NMU in the pathogenesis of asthma, the present review evaluates the potential mechanisms underlying the impact of NMU on asthma and its association with asthma therapy.
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Affiliation(s)
- Xiaojie Ren
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China.,Department of Anaesthesiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Fang Dong
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China.,Department of Anaesthesiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Yuerong Zhuang
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China.,Department of Anaesthesiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Yong Wang
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China.,Department of Anaesthesiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Wuhua Ma
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China.,Department of Anaesthesiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
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11
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Crosson T, Roversi K, Balood M, Othman R, Ahmadi M, Wang JC, Seadi Pereira PJ, Tabatabaei M, Couture R, Eichwald T, Latini A, Prediger RD, Rangachari M, Seehus CR, Foster SL, Talbot S. Profiling of how nociceptor neurons detect danger - new and old foes. J Intern Med 2019; 286:268-289. [PMID: 31282104 DOI: 10.1111/joim.12957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of TH 1-mediated immunity but also as drivers of TH 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.
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Affiliation(s)
- T Crosson
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - K Roversi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Balood
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - R Othman
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - M Ahmadi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - J-C Wang
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | - M Tabatabaei
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - R Couture
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - T Eichwald
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - A Latini
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - R D Prediger
- Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Rangachari
- Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - C R Seehus
- FM Kirby Neurobiology Center, Children's Hospital, Boston, MA, USA
| | - S L Foster
- Depression Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | - S Talbot
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
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12
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Basso L, Serhan N, Tauber M, Gaudenzio N. Peripheral neurons: Master regulators of skin and mucosal immune response. Eur J Immunol 2019; 49:1984-1997. [DOI: 10.1002/eji.201848027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/06/2019] [Accepted: 07/17/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Lilian Basso
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde (UDEAR), UMR 1056, INSERM Université de Toulouse Toulouse France
| | - Nadine Serhan
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde (UDEAR), UMR 1056, INSERM Université de Toulouse Toulouse France
| | - Marie Tauber
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde (UDEAR), UMR 1056, INSERM Université de Toulouse Toulouse France
| | - Nicolas Gaudenzio
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde (UDEAR), UMR 1056, INSERM Université de Toulouse Toulouse France
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13
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Kistemaker LEM, Prakash YS. Airway Innervation and Plasticity in Asthma. Physiology (Bethesda) 2019; 34:283-298. [PMID: 31165683 PMCID: PMC6863372 DOI: 10.1152/physiol.00050.2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 12/22/2022] Open
Abstract
Airway nerves represent a mechanistically and therapeutically important aspect that requires better highlighting in the context of diseases such as asthma. Altered structure and function (plasticity) of afferent and efferent airway innervation can contribute to airway diseases. We describe established anatomy, current understanding of how plasticity occurs, and contributions of plasticity to asthma, focusing on target-derived growth factors (neurotrophins). Perspectives toward novel treatment strategies and future research are provided.
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Affiliation(s)
- L E M Kistemaker
- Department of Molecular Pharmacology, University of Groningen , Groningen , The Netherlands
- GRIAC Research Institute, University Medical Center Groningen, University of Groningen , Groningen , The Netherlands
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic , Rochester, Minnesota
- Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
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14
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de Lartigue G, Xu C. Mechanisms of vagal plasticity influencing feeding behavior. Brain Res 2018; 1693:146-150. [PMID: 29903616 PMCID: PMC6996925 DOI: 10.1016/j.brainres.2018.03.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 12/18/2022]
Abstract
Sensory neurons of the vagus nerve receive many different peripheral signals that can change rapidly and frequently throughout the day. The ability of these neurons to convey the vast array of nuanced information to the brain requires neuronal adaptability. In this review we discuss evidence for neural plasticity in vagal afferent neurons as a mechanism for conveying nuanced information to the brain important for the control of feeding behavior. We provide evidence that synaptic plasticity, changes in membrane conductance, and neuropeptide specification are mechanisms that allow flexibility in response to metabolic cues that can be disrupted by chronic intake of energy dense diets.
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Affiliation(s)
| | - Chelsea Xu
- Department Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
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15
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Voisin T, Bouvier A, Chiu IM. Neuro-immune interactions in allergic diseases: novel targets for therapeutics. Int Immunol 2018; 29:247-261. [PMID: 28814067 DOI: 10.1093/intimm/dxx040] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/05/2017] [Indexed: 12/13/2022] Open
Abstract
Recent studies have highlighted an emerging role for neuro-immune interactions in mediating allergic diseases. Allergies are caused by an overactive immune response to a foreign antigen. The peripheral sensory and autonomic nervous system densely innervates mucosal barrier tissues including the skin, respiratory tract and gastrointestinal (GI) tract that are exposed to allergens. It is increasingly clear that neurons actively communicate with and regulate the function of mast cells, dendritic cells, eosinophils, Th2 cells and type 2 innate lymphoid cells in allergic inflammation. Several mechanisms of cross-talk between the two systems have been uncovered, with potential anatomical specificity. Immune cells release inflammatory mediators including histamine, cytokines or neurotrophins that directly activate sensory neurons to mediate itch in the skin, cough/sneezing and bronchoconstriction in the respiratory tract and motility in the GI tract. Upon activation, these peripheral neurons release neurotransmitters and neuropeptides that directly act on immune cells to modulate their function. Somatosensory and visceral afferent neurons release neuropeptides including calcitonin gene-related peptide, substance P and vasoactive intestinal peptide, which can act on type 2 immune cells to drive allergic inflammation. Autonomic neurons release neurotransmitters including acetylcholine and noradrenaline that signal to both innate and adaptive immune cells. Neuro-immune signaling may play a central role in the physiopathology of allergic diseases including atopic dermatitis, asthma and food allergies. Therefore, getting a better understanding of these cellular and molecular neuro-immune interactions could lead to novel therapeutic approaches to treat allergic diseases.
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Affiliation(s)
- Tiphaine Voisin
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Amélie Bouvier
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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16
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Oetjen LK, Kim BS. Interactions of the immune and sensory nervous systems in atopy. FEBS J 2018; 285:3138-3151. [PMID: 29637705 DOI: 10.1111/febs.14465] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/20/2018] [Accepted: 04/03/2018] [Indexed: 12/15/2022]
Abstract
A striking feature underlying all atopic disorders, such as asthma, atopic dermatitis, and food allergy, is the presence of pathologic sensory responses, reflexes, and behaviors. These symptoms, exemplified by chronic airway irritation and cough, chronic itch and scratching, as well as gastrointestinal discomfort and dysfunction, are often cited as the most debilitating aspects of atopic disorders. Emerging studies have highlighted how the immune system shapes the scope and intensity of sensory responses by directly modulating the sensory nervous system. Additionally, factors produced by neurons have demonstrated novel functions in propagating atopic inflammation at barrier surfaces. In this review, we highlight new studies that have changed our understanding of atopy through advances in characterizing the reciprocal interactions between the immune and sensory nervous systems.
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Affiliation(s)
- Landon K Oetjen
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA.,Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Brian S Kim
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO, USA.,Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
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17
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Foster SL, Seehus CR, Woolf CJ, Talbot S. Sense and Immunity: Context-Dependent Neuro-Immune Interplay. Front Immunol 2017; 8:1463. [PMID: 29163530 PMCID: PMC5675863 DOI: 10.3389/fimmu.2017.01463] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/19/2017] [Indexed: 12/21/2022] Open
Abstract
The sensory nervous and immune systems, historically considered autonomous, actually work in concert to promote host defense and tissue homeostasis. These systems interact with each other through a common language of cell surface G protein-coupled receptors and receptor tyrosine kinases as well as cytokines, growth factors, and neuropeptides. While this bidirectional communication is adaptive in many settings, helping protect from danger, it can also become maladaptive and contribute to disease pathophysiology. The fundamental logic of how, where, and when sensory neurons and immune cells contribute to either health or disease remains, however, unclear. Our lab and others’ have begun to explore how this neuro-immune reciprocal dialog contributes to physiological and pathological immune responses and sensory disorders. The cumulative results collected so far indicate that there is an important role for nociceptors (noxious stimulus detecting sensory neurons) in driving immune responses, but that this is highly context dependent. To illustrate this concept, we present our findings in a model of airway inflammation, in which nociceptors seem to have major involvement in type 2 but not type 1 adaptive immunity.
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Affiliation(s)
- Simmie L Foster
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States.,Department of Psychiatry, Harvard Medical School, Boston, MA, United States.,Depression Clinical Research Program, Massachusetts General Hospital, Boston, MA, United States
| | - Corey R Seehus
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Sébastien Talbot
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada
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18
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Keller JA, McGovern AE, Mazzone SB. Translating Cough Mechanisms Into Better Cough Suppressants. Chest 2017; 152:833-841. [DOI: 10.1016/j.chest.2017.05.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/14/2017] [Accepted: 05/17/2017] [Indexed: 12/19/2022] Open
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19
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Mazzone SB, Undem BJ. Vagal Afferent Innervation of the Airways in Health and Disease. Physiol Rev 2017; 96:975-1024. [PMID: 27279650 DOI: 10.1152/physrev.00039.2015] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vagal sensory neurons constitute the major afferent supply to the airways and lungs. Subsets of afferents are defined by their embryological origin, molecular profile, neurochemistry, functionality, and anatomical organization, and collectively these nerves are essential for the regulation of respiratory physiology and pulmonary defense through local responses and centrally mediated neural pathways. Mechanical and chemical activation of airway afferents depends on a myriad of ionic and receptor-mediated signaling, much of which has yet to be fully explored. Alterations in the sensitivity and neurochemical phenotype of vagal afferent nerves and/or the neural pathways that they innervate occur in a wide variety of pulmonary diseases, and as such, understanding the mechanisms of vagal sensory function and dysfunction may reveal novel therapeutic targets. In this comprehensive review we discuss historical and state-of-the-art concepts in airway sensory neurobiology and explore mechanisms underlying how vagal sensory pathways become dysfunctional in pathological conditions.
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Affiliation(s)
- Stuart B Mazzone
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Australia; and Department of Medicine, Johns Hopkins University Medical School, Asthma & Allergy Center, Baltimore, Maryland
| | - Bradley J Undem
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Australia; and Department of Medicine, Johns Hopkins University Medical School, Asthma & Allergy Center, Baltimore, Maryland
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20
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Vigeland CL, Hughes AH, Horton MR. Etiology and treatment of cough in idiopathic pulmonary fibrosis. Respir Med 2016; 123:98-104. [PMID: 28137504 DOI: 10.1016/j.rmed.2016.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 11/07/2016] [Accepted: 12/22/2016] [Indexed: 01/02/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive disease of dysregulated wound healing leading to unremitting scarring and loss of lung function. The predominant symptoms are dyspnea on exertion and a persistent dry cough. For patients with IPF, cough is more than just bothersome; it has a significant negative impact on quality of life and is a marker of disease severity and progression. The etiology of cough in IPF is unclear but may be due to architectural distortion of the lungs, increased sensitivity of the cough reflex, airway inflammation, or changes in mucus production and clearance. There also may be an overlap between IPF cough and cough due to other common etiologies such as asthma, gastroesophageal reflux disease, upper airway cough syndrome, and medications. There are no approved therapies to specifically treat IPF cough, and recently approved medications for IPF have not been evaluated in cough. Few clinical trials have focused on treatments for IPF cough. To date, there is only one randomized, placebo control therapeutic study for IPF cough with thalidomide, which significantly reduced IPF cough and improved quality of life. Two additional cohort studies report that interferon-α and prednisolone also decrease IPF cough. However, no medication is approved to treat IPF cough. Currently, the mainstay of therapy for IPF cough is standard cough suppressants, which have limited efficacy and often intolerable side effects. Future studies are needed to determine an effective therapy to alleviate this particularly debilitating symptom and improve overall quality of life for patients suffering with IPF.
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Affiliation(s)
- Christine L Vigeland
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States
| | - Andrew H Hughes
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States
| | - Maureen R Horton
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States.
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21
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Zaccone EJ, Lieu T, Muroi Y, Potenzieri C, Undem BE, Gao P, Han L, Canning BJ, Undem BJ. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways. PLoS One 2016; 11:e0155526. [PMID: 27213574 PMCID: PMC4877001 DOI: 10.1371/journal.pone.0155526] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 04/29/2016] [Indexed: 02/06/2023] Open
Abstract
The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ “cough receptors” such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli.
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Affiliation(s)
- Eric J. Zaccone
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - TinaMarie Lieu
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Yukiko Muroi
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Carl Potenzieri
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Blair E. Undem
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Peisong Gao
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Liang Han
- The Solomon H. Snyder Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Brendan J. Canning
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Bradley J. Undem
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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22
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Atkinson SK, Sadofsky LR, Morice AH. How does rhinovirus cause the common cold cough? BMJ Open Respir Res 2016; 3:e000118. [PMID: 26835135 PMCID: PMC4716235 DOI: 10.1136/bmjresp-2015-000118] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/18/2015] [Indexed: 01/13/2023] Open
Abstract
Cough is a protective reflex to prevent aspiration and can be triggered by a multitude of stimuli. The commonest form of cough is caused by upper respiratory tract infection and has no benefit to the host. The virus hijacks this natural defence mechanism in order to propagate itself through the population. Despite the resolution of the majority of cold symptoms within 2 weeks, cough can persist for some time thereafter. Unfortunately, the mechanism of infectious cough brought on by pathogenic viruses, such as human rhinovirus, during colds, remains elusive despite the extensive work that has been undertaken. For socioeconomic reasons, it is imperative we identify the mechanism of cough. There are several theories which have been proposed as the causative mechanism of cough in rhinovirus infection, encompassing a range of different processes. Those of which hold most promise are physical disruption of the epithelial lining, excess mucus production and an inflammatory response to rhinovirus infection which may be excessive. And finally, neuronal modulation, the most convincing hypothesis, is thought to potentiate cough long after the original stimulus has been cleared. All these hypotheses will be briefly covered in the following sections.
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Affiliation(s)
- Samantha K Atkinson
- Centre for Cardiovascular and Metabolic Research (CCMR), The Hull York Medical School (HYMS), The University of Hull , Hull , UK
| | - Laura R Sadofsky
- Centre for Cardiovascular and Metabolic Research (CCMR), The Hull York Medical School (HYMS), The University of Hull , Hull , UK
| | - Alyn H Morice
- Centre for Cardiovascular and Metabolic Research (CCMR), The Hull York Medical School (HYMS), The University of Hull , Hull , UK
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23
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Airway Vagal Neuroplasticity Associated with Respiratory Viral Infections. Lung 2015; 194:25-9. [PMID: 26678280 DOI: 10.1007/s00408-015-9832-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/08/2015] [Indexed: 01/19/2023]
Abstract
Respiratory virus infections leads to coughing, sneezing, and increases in reflex parasympathetic bronchoconstriction and secretions. These responses to viral infection are exclusively or largely secondary to changes in the function of the nervous system. For many with underlying airway pathologies such as asthma and COPD, this neuroplasticity can lead to disease exacerbations and hospitalization. Relatively little is understood about the cellular and molecular mechanisms that underlie the changes in neuronal control of the respiratory tract during viral infection, but the evidence supports the idea that changes occur in the physiology of both the sensory and autonomic innervation. Virus infection can lead to acute increases in the activity of sensory nerves as well as to genetic changes causing alterations in sensory nerve phenotype. In addition, respiratory viral infections are associated with changes in the control of neurotransmitter release from cholinergic nerve endings terminating at the level of the airway smooth muscle.
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24
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Troy AE, Simmonds SS, Stocker SD, Browning KN. High fat diet attenuates glucose-dependent facilitation of 5-HT3 -mediated responses in rat gastric vagal afferents. J Physiol 2015; 594:99-114. [PMID: 26456775 DOI: 10.1113/jp271558] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/04/2015] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Glucose regulates the density and function of 5-HT3 receptors on gastric vagal afferent neurones. Diet-induced obesity compromises the excitability and responsiveness of vagal afferents. In this study, we assessed whether exposure to a high fat diet (HFD) compromises the glucose-dependent modulation of 5-HT responses in gastric vagal afferents prior to the development of obesity. We show that HFD does not alter the response of gastric vagal afferent nerves and neurones to 5-HT but attenuates the ability of glucose to amplify 5-HT3-induced responses. These results suggest that glucose-dependent vagal afferent signalling is compromised by relatively short periods of exposure to HFD well in advance of the development of obesity or glycaemic dysregulation. Glucose regulates the density and function of 5-HT3 receptors on gastric vagal afferent neurones. Since diet-induced obesity attenuates the responsiveness of gastric vagal afferents to several neurohormones, the aim of the present study was to determine whether high fat diet (HFD) compromises the glucose-dependent modulation of 5-HT responses in gastric vagal afferents prior to the development of obesity. Rats were fed control or HFD (14% or 60% kilocalories from fat, respectively) for up to 8 weeks. Neurophysiological recordings assessed the ability of 5-HT to increase anterior gastric vagal afferent nerve (VAN) activity in vivo before and after acute hyperglycaemia, while electrophysiological recordings from gastric-projecting nodose neurones assessed the ability of glucose to modulate the 5-HT response in vitro. Immunocytochemical studies determined alterations in the neuronal distribution of 5-HT3 receptors. 5-HT and cholecystokinin (CCK) induced dose-dependent increases in VAN activity in all rats; HFD attenuated the response to CCK, but not 5-HT. The 5-HT-induced response was amplified by acute hyperglycaemia in control, but not HFD, rats. Similarly, although 5-HT induced an inward current in both control and HFD gastric nodose neurones in vitro, the 5-HT response and receptor distribution was amplified by acute hyperglycaemia only in control rats. These data suggest that, while HFD does not affect the response of gastric-projecting vagal afferents to 5-HT, it attenuates the ability of glucose to amplify 5-HT effects. This suggests that glucose-dependent vagal afferent signalling is compromised by short periods of exposure to HFD well in advance of obesity or glycaemic dysregulation.
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Affiliation(s)
- Amanda E Troy
- Department of Neural and Behavioural Sciences, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Sarah S Simmonds
- Department of Cellular and Integrative Physiology, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Sean D Stocker
- Department of Neural and Behavioural Sciences, Penn State University College of Medicine, Hershey, PA, 17033, USA.,Department of Cellular and Integrative Physiology, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Kirsteen N Browning
- Department of Neural and Behavioural Sciences, Penn State University College of Medicine, Hershey, PA, 17033, USA
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25
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Niimi A, Chung KF. Evidence for neuropathic processes in chronic cough. Pulm Pharmacol Ther 2015; 35:100-4. [PMID: 26474678 DOI: 10.1016/j.pupt.2015.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/09/2015] [Accepted: 10/09/2015] [Indexed: 12/16/2022]
Abstract
Chronic cough is a very common symptom for which patients seek medical attention but can often be difficult to manage, because associated causes may remain elusive and treatment of any associated causes does not always provide adequate relief. Current antitussives have limited efficacy and undesirable side-effects. Patients with chronic cough typically describe sensory symptoms suggestive of upper airway and laryngeal neural dysfunction. They often report cough triggered by low-level physical and chemical stimuli supporting the recently emerging concept of 'cough hypersensitivity syndrome'. Chronic cough is a neuropathic condition that could be secondary to sensory nerve damage caused by inflammatory, infective and allergic factors. Mechanisms underlying peripheral and central augmentation of the afferent cough pathways have been identified. Successful treatment of chronic cough with agents used for treating neuropathic pain, such as gabapentin and amitriptyline, would also support this concept. Further research of neuropathic cough may lead to the discovery of more effective antitussives in the future.
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Affiliation(s)
- Akio Niimi
- Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
| | - Kian Fan Chung
- Experimental Studies, National Heart and Lung Institute, Imperial College London, UK; Royal Brompton NIHR Biomedical Research Unit, London, UK
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26
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Silencing Nociceptor Neurons Reduces Allergic Airway Inflammation. Neuron 2015; 87:341-54. [PMID: 26119026 DOI: 10.1016/j.neuron.2015.06.007] [Citation(s) in RCA: 291] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 04/16/2015] [Accepted: 06/01/2015] [Indexed: 01/15/2023]
Abstract
Lung nociceptors initiate cough and bronchoconstriction. To elucidate if these fibers also contribute to allergic airway inflammation, we stimulated lung nociceptors with capsaicin and observed increased neuropeptide release and immune cell infiltration. In contrast, ablating Nav1.8(+) sensory neurons or silencing them with QX-314, a charged sodium channel inhibitor that enters via large-pore ion channels to specifically block nociceptors, substantially reduced ovalbumin- or house-dust-mite-induced airway inflammation and bronchial hyperresponsiveness. We also discovered that IL-5, a cytokine produced by activated immune cells, acts directly on nociceptors to induce the release of vasoactive intestinal peptide (VIP). VIP then stimulates CD4(+) and resident innate lymphoid type 2 cells, creating an inflammatory signaling loop that promotes allergic inflammation. Our results indicate that nociceptors amplify pathological adaptive immune responses and that silencing these neurons with QX-314 interrupts this neuro-immune interplay, revealing a potential new therapeutic strategy for asthma.
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27
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NMDA and GABA receptors as potential targets in cough hypersensitivity syndrome. Curr Opin Pharmacol 2015; 22:29-36. [DOI: 10.1016/j.coph.2015.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/21/2022]
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28
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Airway extravasation induced by increasing airway temperature in ovalbumin-sensitized rats. Respir Physiol Neurobiol 2015; 212-214:46-9. [PMID: 25864799 DOI: 10.1016/j.resp.2015.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/01/2015] [Accepted: 04/03/2015] [Indexed: 11/22/2022]
Abstract
This study was carried out to determine whether hyperventilation of humidified warm air (HWA) induced airway extravasation in ovalbumin (Ova)-sensitized rats. Our results showed: (1) After isocapnic hyperventilation with HWA for 2 min, tracheal temperature (Ttr) was increased to 40.3°C, and the Evans blue contents in major airways and lung tissue were elevated to 651% and 707%, respectively, of that after hyperventilation with humidified room air in Ova-sensitized rats; this striking effect of HWA was absent in control rats. (2) The HWA-induced increase in Evans blue content in sensitized rats was completely prevented by a pretreatment with either L-732138, a selective antagonist of neurokinin type 1 (NK-1) receptor, or formoterol, a selective agonist of β2 adrenoceptor. This study demonstrated that an increase in airway temperature induced protein extravasation in the major airways and lung tissue of sensitized rats, and an activation of the NK-1 receptor by tachykinins released from bronchopulmonary C-fiber nerve endings was primarily responsible.
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29
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Herrity AN, Petruska JC, Stirling DP, Rau KK, Hubscher CH. The effect of spinal cord injury on the neurochemical properties of vagal sensory neurons. Am J Physiol Regul Integr Comp Physiol 2015; 308:R1021-33. [PMID: 25855310 DOI: 10.1152/ajpregu.00445.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/01/2015] [Indexed: 12/29/2022]
Abstract
The vagus nerve is composed primarily of nonmyelinated sensory neurons whose cell bodies are located in the nodose ganglion (NG). The vagus has widespread projections that supply most visceral organs, including the bladder. Because of its nonspinal route, the vagus nerve itself is not directly damaged from spinal cord injury (SCI). Because most viscera, including bladder, are dually innervated by spinal and vagal sensory neurons, an impact of SCI on the sensory component of vagal circuitry may contribute to post-SCI visceral pathologies. To determine whether SCI, in male Wistar rats, might impact neurochemical characteristics of NG neurons, immunohistochemical assessments were performed for P2X3 receptor expression, isolectin B4 (IB4) binding, and substance P expression, three known injury-responsive markers in sensory neuronal subpopulations. In addition to examining the overall population of NG neurons, those innervating the urinary bladder also were assessed separately. All three of the molecular markers were represented in the NG from noninjured animals, with the majority of the neurons binding IB4. In the chronically injured rats, there was a significant increase in the number of NG neurons expressing P2X3 and a significant decrease in the number binding IB4 compared with noninjured animals, a finding that held true also for the bladder-innervating population. Overall, these results indicate that vagal afferents, including those innervating the bladder, display neurochemical plasticity post-SCI that may have implications for visceral homeostatic mechanisms and nociceptive signaling.
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Affiliation(s)
- April N Herrity
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
| | - Jeffrey C Petruska
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky; Department of Neurological Surgery, University of Louisville, Louisville, Kentucky
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky; Department of Neurological Surgery, University of Louisville, Louisville, Kentucky; Department of Microbiology & Immunology, University of Louisville School of Medicine, Louisville, Kentucky; and
| | - Kristofer K Rau
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky; Department of Anesthesiology, University of Louisville, Louisville, Kentucky
| | - Charles H Hubscher
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky;
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McAlexander MA, Gavett SH, Kollarik M, Undem BJ. Vagotomy reverses established allergen-induced airway hyperreactivity to methacholine in the mouse. Respir Physiol Neurobiol 2015; 212-214:20-4. [PMID: 25842220 DOI: 10.1016/j.resp.2015.03.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 11/26/2022]
Abstract
We evaluated the role of vagal reflexes in a mouse model of allergen-induced airway hyperreactivity. Mice were actively sensitized to ovalbumin then exposed to the allergen via inhalation. Prior to ovalbumin inhalation, mice also received intratracheally-instilled particulate matter in order to boost the allergic response. In control mice, methacholine (i.v.) caused a dose-dependent increase in respiratory tract resistance (RT) that only modestly decreased if the vagi were severed bilaterally just prior to the methacholine challenge. Sensitized and challenged mice, however, manifested an airway reactivity increase that was abolished by severing the vagi prior to methacholine challenge. In an innervated ex vivo mouse lung model, methacholine selectively evoked action potential discharge in a subset of distension-sensitive A-fibers. These data support the hypothesis that the major component of the increased airway reactivity in inflamed mice is due to a vagal reflex initiated by activation of afferent fibers, even in response to a direct (i.e., smooth muscle)-acting muscarinic agonist.
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Affiliation(s)
| | - Stephen H Gavett
- EPHD, NHEERL, United States Environmental Protection Agency, Research Triangle Park, NC, United States
| | - Marian Kollarik
- Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Bradley J Undem
- Johns Hopkins School of Medicine, Baltimore, MD, United States.
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Varechova S, Demoulin B, Leblanc AL, Coutier L, Ioan I, Bonabel C, Schweitzer C, Marchal F. Neonatal hyperoxia up regulates cough reflex in young rabbits. Respir Physiol Neurobiol 2015; 208:51-6. [DOI: 10.1016/j.resp.2015.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/09/2014] [Accepted: 01/02/2015] [Indexed: 12/24/2022]
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Peripheral neural circuitry in cough. Curr Opin Pharmacol 2015; 22:9-17. [PMID: 25704498 DOI: 10.1016/j.coph.2015.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/02/2015] [Accepted: 02/04/2015] [Indexed: 01/22/2023]
Abstract
Cough is a reflex that serves to protect the airways. Excessive or chronic coughing is a major health issue that is poorly controlled by current therapeutics. Significant effort has been made to understand the mechanisms underlying the cough reflex. The focus of this review is the evidence supporting the role of specific airway sensory nerve (afferent) populations in the initiation and modulation of the cough reflex in health and disease.
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Bonvini SJ, Birrell MA, Smith JA, Belvisi MG. Targeting TRP channels for chronic cough: from bench to bedside. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:401-20. [PMID: 25572384 DOI: 10.1007/s00210-014-1082-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 12/16/2014] [Indexed: 12/24/2022]
Abstract
Cough is currently the most common reason for patients to visit a primary care physician in the UK, yet it remains an unmet medical need. Current therapies have limited efficacy or have potentially dangerous side effects. Under normal circumstances, cough is a protective reflex to clear the lungs of harmful particles; however, in disease, cough can become excessive, dramatically impacting patients' lives. In many cases, this condition is linked to inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD), but can also be refractory to treatment and idiopathic in nature. Therefore, there is an urgent need to develop therapies, and targeting the sensory afferent arm of the reflex which initiates the cough reflex may uncover novel therapeutic targets. The cough reflex is initiated following activation of ion channels present on vagal sensory afferents. These ion channels include the transient receptor potential (TRP) family of cation-selective ion channels which act as cellular sensors and respond to changes in the external environment. Many direct activators of TRP channels, including arachidonic acid derivatives, a lowered airway pH, changes in temperature, and altered airway osmolarity are present in the diseased airway where responses to challenge agents which activate airway sensory nerve activity are known to be enhanced. Furthermore, the expression of some TRP channels is increased in airway disease. Together, this makes them promising targets for the treatment of chronic cough. This review will cover the current understanding of the role of the TRP family of ion channels in the activation of airway sensory nerves and cough, focusing on four members, transient receptor potential vanilloid (TRPV) 1, transient receptor potential ankyrin (TRPA) 1, TRPV4, and transient receptor potential melastatin (TRPM) 8 as these represent the channels where most information has been gathered with relevance to the airways. We will describe recent data and highlight the possible therapeutic utility of specific TRP channel antagonists as antitussives in the clinic.
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Affiliation(s)
- Sara J Bonvini
- Respiratory Pharmacology Group, Airway Disease Section, National Heart & Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
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Abstract
Sensory nerves innervating the lung and airways play an important role in regulating various cardiopulmonary functions and maintaining homeostasis under both healthy and disease conditions. Their activities conducted by both vagal and sympathetic afferents are also responsible for eliciting important defense reflexes that protect the lung and body from potential health-hazardous effects of airborne particulates and chemical irritants. This article reviews the morphology, transduction properties, reflex functions, and respiratory sensations of these receptors, focusing primarily on recent findings derived from using new technologies such as neural immunochemistry, isolated airway-nerve preparation, cultured airway neurons, patch-clamp electrophysiology, transgenic mice, and other cellular and molecular approaches. Studies of the signal transduction of mechanosensitive afferents have revealed a new concept of sensory unit and cellular mechanism of activation, and identified additional types of sensory receptors in the lung. Chemosensitive properties of these lung afferents are further characterized by the expression of specific ligand-gated ion channels on nerve terminals, ganglion origin, and responses to the action of various inflammatory cells, mediators, and cytokines during acute and chronic airway inflammation and injuries. Increasing interest and extensive investigations have been focused on uncovering the mechanisms underlying hypersensitivity of these airway afferents, and their role in the manifestation of various symptoms under pathophysiological conditions. Several important and challenging questions regarding these sensory nerves are discussed. Searching for these answers will be a critical step in developing the translational research and effective treatments of airway diseases.
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Affiliation(s)
- Lu-Yuan Lee
- Department of Physiology, University of Kentucky, Lexington, Kentucky
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Bhagat R, Fortna SR, Browning KN. Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity. J Physiol 2014; 593:285-303. [PMID: 25556801 DOI: 10.1113/jphysiol.2014.282806] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 10/24/2014] [Indexed: 01/02/2023] Open
Abstract
KEY POINTS Obesity is recognized as being multifactorial in origin, involving both genetic and environmental factors. The perinatal period is known to be critically important in the development of neural circuits responsible for energy homeostasis and the integration of autonomic reflexes. Diet-induced obesity alters the biophysical, pharmacological and morphological properties of vagal neurocircuits regulating upper gastrointestinal tract functions, including satiety. Less information is available, however, regarding the effects of a high fat diet (HFD) itself on the properties of vagal neurocircuits. The present study was designed to test the hypothesis that exposure to a HFD during the perinatal period alters the electrophysiological, pharmacological and morphological properties of vagal efferent motoneurones innervating the stomach. Our data indicate that perinatal HFD decreases the excitability of gastric-projecting dorsal motor nucleus neurones and dysregulates neurotransmitter release from synaptic inputs and that these alterations occur prior to the development of obesity. These findings represent the first direct evidence that exposure to a HFD modulates the processing of central vagal neurocircuits even in the absence of obesity. The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin brainstem slices from rats that were exposed to either a control diet or HFD from pregnancy day 13. Our data demonstrate that following perinatal HFD: (i) DMV neurones had decreased excitability and input resistance with a reduced ability to fire action potentials; (ii) the proportion of DMV neurones excited by cholecystokinin (CCK) was unaltered but the proportion of neurones in which CCK increased excitatory glutamatergic synaptic inputs was reduced; (iii) the tonic activation of presynaptic group II metabotropic glutamate receptors on inhibitory nerve terminals was attenuated, allowing modulation of GABAergic synaptic transmission; and (iv) the size and dendritic arborization of gastric-projecting DMV neurones was increased. These results suggest that perinatal HFD exposure compromises the excitability and responsiveness of gastric-projecting DMV neurones, even in the absence of obesity, suggesting that attenuation of vago-vagal reflex signalling may precede the development of obesity.
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Affiliation(s)
- Ruchi Bhagat
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, PA 17033, USA
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Chung KF. Approach to chronic cough: the neuropathic basis for cough hypersensitivity syndrome. J Thorac Dis 2014; 6:S699-707. [PMID: 25383203 DOI: 10.3978/j.issn.2072-1439.2014.08.41] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 08/21/2014] [Indexed: 12/29/2022]
Abstract
Chronic cough is a common symptom that can be difficult to manage because associated causes may remain elusive and treatment of any associated cause may not provide relief. Current antitussives have limited efficacy and undesirable side-effects. Patients with chronic cough describe sensory symptoms suggestive of upper airway and laryngeal neural dysfunction, and report cough triggered by low-level physical and chemical stimuli supporting the concept of cough reflex hypersensitivity. Mechanisms underlying peripheral and central augmentation of the afferent cough pathways have been identified. Chronic cough is a neuropathic condition that could be secondary to sensory nerve damage caused by inflammatory, infective and allergic factors. Recent success in the treatment of chronic cough with agents used for treating neuropathic pain such as gabapentin and amitryptiline would also support this concept. Research into neuropathic cough may lead to the discovery of more effective antitussives.
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Affiliation(s)
- Kian Fan Chung
- Experimental Studies Unit, National Heart & Lung Institute, Imperial College London and Biomedical Research Unit, Royal Brompton Hospital, London, UK
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Ioan I, Poussel M, Coutier L, Plevkova J, Poliacek I, Bolser DC, Davenport PW, Derelle J, Hanacek J, Tatar M, Marchal F, Schweitzer C, Fontana G, Varechova S. What is chronic cough in children? Front Physiol 2014; 5:322. [PMID: 25221517 PMCID: PMC4148026 DOI: 10.3389/fphys.2014.00322] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/05/2014] [Indexed: 01/28/2023] Open
Abstract
The cough reflex is modulated throughout growth and development. Cough—but not expiration reflex—appears to be absent at birth, but increases with maturation. Thus, acute cough is the most frequent respiratory symptom during the first few years of life. Later on, the pubertal development seems to play a significant role in changing of the cough threshold during childhood and adolescence resulting in sex-related differences in cough reflex sensitivity in adulthood. Asthma is the major cause of chronic cough in children. Prolonged acute cough is usually related to the long-lasting effects of a previous viral airway infection or to the particular entity called protracted bacterial bronchitis. Cough pointers and type may orient toward specific etiologies, such as barking cough in croup or tracheomalacia, paroxystic whooping cough in Pertussis. Cough is productive in protracted bacterial bronchitis, sinusitis or bronchiectasis. Cough is usually associated with wheeze or dyspnea on exertion in asthma; however, it may be the sole symptom in cough variant asthma. Thus, pediatric cough has particularities differentiating it from adult cough, so the approach and management should be developmentally specific.
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Affiliation(s)
- Iulia Ioan
- Service D'explorations Fonctionnelles Pédiatriques, Hôpital D'enfants Centre Hospitalier Universitaire de Nancy, Vandoeuvre les Nancy, France
| | - Mathias Poussel
- Service Des Examens de la Fonction Respiratoire et de L'aptitude à L'exercice Centre Hospitalier Universitaire de Nancy, Vandoeuvre les Nancy, France ; EA 3450 DevAH - Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine Vandoeuvre, France
| | - Laurianne Coutier
- EA 3450 DevAH - Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine Vandoeuvre, France
| | - Jana Plevkova
- Department of Pathophysiology, Jessenius Faculty of Medicine, Comenius University Martin, Slovakia
| | - Ivan Poliacek
- Institute of Medical Biophysics, Jessenius Faculty of Medicine, Comenius University Martin, Slovakia
| | - Donald C Bolser
- Department of Physiological Sciences, University of Florida Gainesville, FL, USA
| | - Paul W Davenport
- Department of Physiological Sciences, University of Florida Gainesville, FL, USA
| | - Jocelyne Derelle
- Service de Médecine Infantile et de Génétique Clinique, Hôpital D'enfants Vandœuvre-lès-Nancy, France
| | - Jan Hanacek
- Department of Pathophysiology, Jessenius Faculty of Medicine, Comenius University Martin, Slovakia
| | - Milos Tatar
- Department of Pathophysiology, Jessenius Faculty of Medicine, Comenius University Martin, Slovakia
| | - François Marchal
- Service D'explorations Fonctionnelles Pédiatriques, Hôpital D'enfants Centre Hospitalier Universitaire de Nancy, Vandoeuvre les Nancy, France ; EA 3450 DevAH - Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine Vandoeuvre, France
| | - Cyril Schweitzer
- Service D'explorations Fonctionnelles Pédiatriques, Hôpital D'enfants Centre Hospitalier Universitaire de Nancy, Vandoeuvre les Nancy, France ; EA 3450 DevAH - Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine Vandoeuvre, France ; Service de Médecine Infantile et de Génétique Clinique, Hôpital D'enfants Vandœuvre-lès-Nancy, France
| | - Giovanni Fontana
- Department of Internal Medicine, University of Florence Florence, Italy
| | - Silvia Varechova
- Service D'explorations Fonctionnelles Pédiatriques, Hôpital D'enfants Centre Hospitalier Universitaire de Nancy, Vandoeuvre les Nancy, France ; EA 3450 DevAH - Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine Vandoeuvre, France
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Brito R, Sheth S, Mukherjea D, Rybak LP, Ramkumar V. TRPV1: A Potential Drug Target for Treating Various Diseases. Cells 2014; 3:517-45. [PMID: 24861977 PMCID: PMC4092862 DOI: 10.3390/cells3020517] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 05/14/2014] [Accepted: 05/15/2014] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is an ion channel present on sensory neurons which is activated by heat, protons, capsaicin and a variety of endogenous lipids termed endovanilloids. As such, TRPV1 serves as a multimodal sensor of noxious stimuli which could trigger counteractive measures to avoid pain and injury. Activation of TRPV1 has been linked to chronic inflammatory pain conditions and peripheral neuropathy, as observed in diabetes. Expression of TRPV1 is also observed in non-neuronal sites such as the epithelium of bladder and lungs and in hair cells of the cochlea. At these sites, activation of TRPV1 has been implicated in the pathophysiology of diseases such as cystitis, asthma and hearing loss. Therefore, drugs which could modulate TRPV1 channel activity could be useful for the treatment of conditions ranging from chronic pain to hearing loss. This review describes the roles of TRPV1 in the normal physiology and pathophysiology of selected organs of the body and highlights how drugs targeting this channel could be important clinically.
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Affiliation(s)
- Rafael Brito
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Sandeep Sheth
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Debashree Mukherjea
- Department of Surgery (Otoloryngalogy), Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Leonard P Rybak
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Vickram Ramkumar
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
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Grace MS, Baxter M, Dubuis E, Birrell MA, Belvisi MG. Transient receptor potential (TRP) channels in the airway: role in airway disease. Br J Pharmacol 2014; 171:2593-607. [PMID: 24286227 PMCID: PMC4009002 DOI: 10.1111/bph.12538] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 11/18/2013] [Indexed: 12/16/2022] Open
Abstract
Over the last few decades, there has been an explosion of scientific publications reporting the many and varied roles of transient receptor potential (TRP) ion channels in physiological and pathological systems throughout the body. The aim of this review is to summarize the existing literature on the role of TRP channels in the lungs and discuss what is known about their function under normal and diseased conditions. The review will focus mainly on the pathogenesis and symptoms of asthma and chronic obstructive pulmonary disease and the role of four members of the TRP family: TRPA1, TRPV1, TRPV4 and TRPM8. We hope that the article will help the reader understand the role of TRP channels in the normal airway and how their function may be changed in the context of respiratory disease.
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Affiliation(s)
- M S Grace
- Respiratory Pharmacology, National Heart and Lung Institute, Faculty of Medicine, Imperial College LondonLondon, UK
| | - M Baxter
- Respiratory Pharmacology, National Heart and Lung Institute, Faculty of Medicine, Imperial College LondonLondon, UK
| | - E Dubuis
- Respiratory Pharmacology, National Heart and Lung Institute, Faculty of Medicine, Imperial College LondonLondon, UK
| | - M A Birrell
- Respiratory Pharmacology, National Heart and Lung Institute, Faculty of Medicine, Imperial College LondonLondon, UK
| | - M G Belvisi
- Respiratory Pharmacology, National Heart and Lung Institute, Faculty of Medicine, Imperial College LondonLondon, UK
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Undem BJ, Taylor-Clark T. Mechanisms underlying the neuronal-based symptoms of allergy. J Allergy Clin Immunol 2014; 133:1521-34. [PMID: 24433703 DOI: 10.1016/j.jaci.2013.11.027] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/05/2013] [Accepted: 11/13/2013] [Indexed: 12/13/2022]
Abstract
Persons with allergies present with symptoms that often are the result of alterations in the nervous system. Neuronally based symptoms depend on the organ in which the allergic reaction occurs but can include red itchy eyes, sneezing, nasal congestion, rhinorrhea, coughing, bronchoconstriction, airway mucus secretion, dysphagia, altered gastrointestinal motility, and itchy swollen skin. These symptoms occur because mediators released during an allergic reaction can interact with sensory nerves, change processing in the central nervous system, and alter transmission in sympathetic, parasympathetic, and enteric autonomic nerves. In addition, evidence supports the idea that in some subjects this neuromodulation is, for reasons poorly understood, upregulated such that the same degree of nerve stimulus causes a larger effect than seen in healthy subjects. There are distinctions in the mechanisms and nerve types involved in allergen-induced neuromodulation among different organ systems, but general principles have emerged. The products of activated mast cells, other inflammatory cells, and resident cells can overtly stimulate nerve endings, cause long-lasting changes in neuronal excitability, increase synaptic efficacy, and also change gene expression in nerves, resulting in phenotypically altered neurons. A better understanding of these processes might lead to novel therapeutic strategies aimed at limiting the suffering of those with allergies.
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Affiliation(s)
- Bradley J Undem
- Division of Allergy & Clinical Immunology, Johns Hopkins School of Medicine, Baltimore, Md.
| | - Thomas Taylor-Clark
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Fla
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Oh MH, Oh SY, Lu J, Lou H, Myers AC, Zhu Z, Zheng T. TRPA1-dependent pruritus in IL-13-induced chronic atopic dermatitis. THE JOURNAL OF IMMUNOLOGY 2013; 191:5371-82. [PMID: 24140646 DOI: 10.4049/jimmunol.1300300] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Chronic debilitating pruritus is a cardinal feature of atopic dermatitis (AD). Little is known about the underlying mechanisms. Antihistamines lack efficacy in treating itch in AD, suggesting the existence of histamine-independent itch pathways in AD. Transient receptor potential ankyrin 1 (TRPA1) is essential in the signaling pathways that promote histamine-independent itch. In this study, we tested the hypothesis that TRPA1-dependent neural pathways play a key role in chronic itch in AD using an IL-13-transgenic mouse model of AD. In these mice, IL-13 causes chronic AD characterized by intensive chronic itch associated with markedly enhanced growth of dermal neuropeptide-secreting afferent nerve fibers and enhanced expression of TRPA1 in dermal sensory nerve fibers, their dorsal root ganglia, and mast cells. Inhibition of TRPA1 with a specific antagonist in these mice selectively attenuated itch-evoked scratching. Genetic deletion of mast cells in these mice led to significantly diminished itch-scratching behaviors and reduced TRPA1 expression in dermal neuropeptide containing afferents in the AD skin. Interestingly, IL-13 strongly stimulates TRPA1 expression, which is functional in calcium mobilization in mast cells. In accordance with these observations in the AD mice, TRPA1 expression was highly enhanced in the dermal afferent nerves, mast cells, and the epidermis in the lesional skin biopsies from patients with AD, but not in the skin from healthy subjects. These studies demonstrate a novel neural mechanism underlying chronic itch in AD and highlight the complex interactions among TRPA1(+) dermal afferent nerves and TRPA1(+) mast cells in a Th2-dominated inflammatory environment.
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Affiliation(s)
- Min-Hee Oh
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21224
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Kichko TI, Lennerz J, Eberhardt M, Babes RM, Neuhuber W, Kobal G, Reeh PW. Bimodal concentration-response of nicotine involves the nicotinic acetylcholine receptor, transient receptor potential vanilloid type 1, and transient receptor potential ankyrin 1 channels in mouse trachea and sensory neurons. J Pharmacol Exp Ther 2013; 347:529-39. [PMID: 23926288 DOI: 10.1124/jpet.113.205971] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
High concentrations of nicotine, as in the saliva of oral tobacco consumers or in smoking cessation aids, have been shown to sensitize/activate recombinant transient receptor potential vanilloid type 1 (rTRPV1) and mouse TRPA1 (mTRPA1) channels. By measuring stimulated calcitonin gene-related peptide (CGRP) release from the isolated mouse trachea, we established a bimodal concentration-response relationship with a threshold below 10 µM (-)-nicotine, a maximum at 100 µM, an apparent nadir between 0.5 and 10 mM, and a renewed increase at 20 mM. The first peak was unchanged in TRPV1/A1 double-null mutants as compared with wild-types and was abolished by specific nicotinic acetylcholine receptor (nAChR) inhibitors and by camphor, discovered to act as nicotinic antagonist. The nicotine response at 20 mM was strongly pHe-dependent, - five times greater at pH 9.0 than 7.4, indicating that intracellular permeation of the (uncharged) alkaloid was required to reach the TRPV1/A1 binding sites. The response was strongly reduced in both null mutants, and more so in double-null mutants. Upon measuring calcium transients in nodose/jugular and dorsal root ganglion neurons in response to 100 µM nicotine, 48% of the vagal (but only 14% of the somatic) sensory neurons were activated, the latter very weakly. However, nicotine 20 mM at pH 9.0 repeatedly activated almost every single cultured neuron, partly by releasing intracellular calcium and independent of TRPV1/A1 and nAChRs. In conclusion, in mouse tracheal sensory nerves nAChRs are 200-fold more sensitive to nicotine than TRPV1/A1; they are widely coexpressed with the capsaicin receptor among vagal sensory neurons and twice as abundant as TRPA1. Nicotine is the major stimulant in tobacco, and its sensory impact through nAChRs should not be disregarded.
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Affiliation(s)
- Tatjana I Kichko
- Institute of Physiology and Pathophysiology (T.I.K., J.L., M.E., R.M.B., P.W.R.) and Institute of Anatomy I (W.N.), Friedrich-Alexander-University, Erlangen, Germany; Institute of Pathology, University of Ulm, Ulm, Germany (J.L.); Department of Biophysics, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania (R.M.B.); Department of Anesthesiology and Intensive Care, Hannover Medical School, Hannover, Germany (M.E.); and Altria Client Services, Inc., Richmond, Virginia (G.K.)
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Hsu CC, Lin RL, Lin YS, Lee LY. Bronchoconstriction induced by increasing airway temperature in ovalbumin-sensitized rats: role of tachykinins. J Appl Physiol (1985) 2013; 115:688-96. [PMID: 23845978 DOI: 10.1152/japplphysiol.00491.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study was carried out to determine the effect of allergic inflammation on the airway response to increasing airway temperature. Our results showed the following: 1) In Brown-Norway rats actively sensitized by ovalbumin (Ova), isocapnic hyperventilation with humidified warm air (HWA) for 2 min raised tracheal temperature (Ttr) from 33.4 ± 0.6°C to 40.6 ± 0.1°C, which induced an immediate and sustained (>10 min) increase in total pulmonary resistance (Rl) from 0.128 ± 0.004 to 0.212 ± 0.013 cmH2O·ml(-1)·s (n = 6, P < 0.01). In sharp contrast, the HWA challenge caused the same increase in Ttr but did not generate any increase in Rl in control rats. 2) The increase in Rl in sensitized rats was reproducible when the same HWA challenge was repeated 60-90 min later. 3) This bronchoconstrictive effect was temperature dependent: a slightly smaller increase in peak Ttr (39.6 ± 0.2°C) generated a significant but smaller increase in Rl in sensitized rats. 4) The HWA-induced bronchoconstriction was not generated by the humidity delivered by the HWA challenge alone, because the same water content delivered by saline aerosol at room temperature had no effect. 5) The HWA-evoked increase in Rl in sensitized rats was not blocked by atropine but was completely prevented by pretreatment either with a combination of neurokinin (NK)-1 and NK-2 antagonists or with formoterol, a β2 agonist, before the HWA challenge. This study showed that increasing airway temperature evoked a pronounced and reversible increase in airway resistance in sensitized rats and that tachykinins released from the vagal bronchopulmonary C-fiber endings were primarily responsible.
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Affiliation(s)
- Chun-Chun Hsu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan, Republic of China
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O'Neill J, McMahon SB, Undem BJ. Chronic cough and pain: Janus faces in sensory neurobiology? Pulm Pharmacol Ther 2013; 26:476-85. [PMID: 23831712 DOI: 10.1016/j.pupt.2013.06.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 06/20/2013] [Accepted: 06/26/2013] [Indexed: 10/26/2022]
Abstract
Both chronic cough and chronic pain are critical clinical issues in which a large number of patients remain unsatisfied with available treatments. These conditions have considerable effects on sufferers' quality of life, who often show co-morbidities such as anxiety and depression. There is therefore a pressing need to find new effective therapies. The basic neurobiological mechanisms and pathologies of these two conditions show substantial homologies. However, whilst chronic pain has received a great deal of attention over the last few decades, the same cannot be said for the neurological underpinnings of chronic cough. There is a substantial literature around mechanisms of chronic pain which is likely to be useful in advancing knowledge about the pathologies of chronic cough. Here we compare the basic pain and cough pathways, in addition to the clinical features and possible pathophysiologies of each; including mechanisms of peripheral and central sensitisation which may underlie symptoms such as hyperalgesia and allodynia, and hypertussitvity and allotussivity. Due to the substantial overlap that emerges, it is likely that therapies may be effective over both areas.
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Affiliation(s)
- Jessica O'Neill
- Neuroscience, Physiology and Pharmacology, University College London, UK. Jessica.o'
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Grace MS, Dubuis E, Birrell MA, Belvisi MG. Pre-clinical studies in cough research: role of Transient Receptor Potential (TRP) channels. Pulm Pharmacol Ther 2013; 26:498-507. [PMID: 23474212 PMCID: PMC3763377 DOI: 10.1016/j.pupt.2013.02.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/19/2013] [Accepted: 02/24/2013] [Indexed: 02/08/2023]
Abstract
Cough is a protective reflex and defence mechanism in healthy individuals, which helps clear excessive secretions and foreign material from the lungs. Cough often presents as the first and most persistent symptom of many respiratory diseases and some non-respiratory disorders, but can also be idiopathic, and is a common respiratory complaint for which medical attention is sought. Chronic cough of various aetiologies is a regular presentation to specialist respiratory clinics, and is reported as a troublesome symptom by a significant proportion of the population. Despite this, the treatment options for cough are limited. The lack of effective anti-tussives likely stems from our incomplete understanding of how the tussive reflex is mediated. However, research over the last decade has begun to shed some light on the mechanisms which provoke cough, and may ultimately provide us with better anti-tussive therapies. This review will focus on the in vitro and in vivo models that are currently used to further our understanding of the sensory innervation of the respiratory tract, and how these nerves are involved in controlling the cough response. Central to this are the Transient Receptor Potential (TRP) ion channels, a family of polymodal receptors that can be activated by such diverse stimuli as chemicals, temperature, osmotic stress, and mechanical perturbation. These ion channels are thought to be molecular pain integrators and targets for novel analgesic agents for the treatment of various pain disorders but some are also being developed as anti-tussives.
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Affiliation(s)
- Megan S Grace
- Respiratory Pharmacology, Pharmacology & Toxicology Section, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, Exhibition Road, London SW7 2AZ, UK
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Browning KN, Fortna SR, Hajnal A. Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones. J Physiol 2013; 591:2357-72. [PMID: 23459752 DOI: 10.1113/jphysiol.2012.249268] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12-14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal neuronal health in the brain by reversing some effects of chronic high-fat diet as well as ageing. Vagovagal neurocircuits appear to remain open to modulation and adaptation throughout life, and understanding of these mechanisms may help in development of novel interventions to alleviate environmental (e.g. dietary) ailments and also alter neuronal ageing.
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Affiliation(s)
- Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, PA 17033, USA.
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Xu X, Li Z, Zou D, Yang M, Liu Z, Wang X. High expression of calcitonin gene-related peptide and substance P in esophageal mucosa of patients with non-erosive reflux disease. Dig Dis Sci 2013; 58:53-60. [PMID: 22961239 DOI: 10.1007/s10620-012-2308-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 06/25/2012] [Indexed: 01/13/2023]
Abstract
BACKGROUND Visceral hypersensitivity is an important etiology of non-erosive reflux disease (NERD). Calcitonin gene-related peptide (CGRP) and substance P (SP) are involved in the sensitization of afferent neuronal pathways. AIM The objectives of this study were to evaluate visceral hypersensitivity in NERD patients, investigate the association between visceral hypersensitivity and mucosal expression of SP and CGRP, and assess their involvement in the pathogenesis of NERD. METHODS Twenty-six NERD patients and 12 healthy volunteers were recruited. Intraesophageal balloon distention was performed, and initial perception threshold (IPT) and threshold of discomfort (ToD) were determined. Immunohistochemical staining was used to measure the optical density (OD) of CGRP and SP-reactive levels in esophageal mucosa, and the numbers of CGRP and SP-reactive neural fibers. RESULTS IPT and ToD were 9.6 ± 4.8 and 12.3 ± 3.2 ml, respectively, in NERD patients, significantly lower than for controls (13.2 ± 7.5 and 21.6 ± 5.7 ml, P < 0.05 and P < 0.01, respectively). Mean OD values for CGRP and SP staining were significantly higher in NERD than for controls (both P < 0.05) and, in NERD, were negatively correlated with IPT and ToD (all P < 0.01). Numbers of CGRP and SP-reactive neural fibers in esophageal submucosa of NERD patients were significantly increased (both P < 0.05). CONCLUSIONS Expression of esophageal epithelial CGRP and SP is increased, and correlates negatively with perception thresholds in NERD. These findings may aid understanding of peripheral visceral hypersensitivity and the development of new therapeutic approaches for management of NERD.
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Affiliation(s)
- Xiaorong Xu
- Department of Gastroenterology, Tenth People's Hospital of Tongji University, Yanchang Road, Shanghai, 200072, China.
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Abstract
Several different electrophysiological approaches have been used to study the pharmacology of the afferent, central, and efferent nervous systems in airways. This unit describes electrophysiological methods used to study nerves in these pathways and includes: (1) extracellular recording of afferent nerve activity in vivo and from the isolated airway in vitro, (2) intracellular and patch clamp recording of identified airway sensory neurons, (3) patch clamp recording of secondary afferent central nervous system neurons, (4) in vitro and in vivo intracellular recording of intact parasympathetic ganglionic neurons, and (5) patch recordings of dissociated parasympathetic ganglionic neurons.
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Affiliation(s)
- Allen C Myers
- The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Lieu TM, Myers AC, Meeker S, Undem BJ. TRPV1 induction in airway vagal low-threshold mechanosensory neurons by allergen challenge and neurotrophic factors. Am J Physiol Lung Cell Mol Physiol 2012; 302:L941-8. [PMID: 22345578 DOI: 10.1152/ajplung.00366.2011] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We addressed the hypothesis that allergic inflammation in guinea pig airways leads to a phenotypic switch in vagal tracheal cough-causing, low-threshold mechanosensitive Aδ neurons, such that they begin expressing functional transient receptor potential vanilloid (TRPV1) channels. Guinea pigs were actively sensitized to ovalbumin (OVA) and beginning 21 days later exposed via aerosol to OVA daily for 3 days. Tracheal-specific neurons were identified in the nodose ganglion using retrograde tracing techniques. Tracheal specific neurons were isolated, and mRNA expression was evaluated at the single-neuron level using RT-PCR analysis. Electrophysiological studies have revealed that the vast majority of vagal nodose afferent nerves innervating the trachea are capsaicin-insensitive Aδ-fibers. Consistent with this, we found <20% of these neurons express TRPV1 mRNA or respond to capsaicin in a calcium assay. Allergen exposure induced de novo TRPV1 mRNA in a majority of the tracheal-specific nodose neurons (P < 0.05). The allergen-induced TRPV1 induction was mimicked by applying either brain-derived neurotrophic factor (BDNF) or glial-derived neurotrophic factor (GDNF) to the tracheal lumen. The BDNF-induced phenotypic change observed at the level of mRNA expression was mimicked using a calcium assay to assess functional TRPV1 ion channels. Finally, OVA exposure induced BDNF and GDNF production in the tracheal epithelium, the immediate vicinity of the nodose Aδ -fibers terminations. The induction of TRPV1 in nodose tracheal Aδ -fibers would substantively expand the nature of stimuli capable of activating these cough-causing nerves.
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Affiliation(s)
- Tina Marie Lieu
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA
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