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Zhuang J, Gao X, Shi S, Xu F. Apneic response to fentanyl in adult rats: Role of laryngeal afferents. Physiol Rep 2024; 12:e15965. [PMID: 38444051 PMCID: PMC10915130 DOI: 10.14814/phy2.15965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/07/2024] Open
Abstract
Intravenous (systemic) bolus injection of fentanyl (FNT) reportedly induces an immediate vagal-mediated apnea; however, the precise origin of vagal afferents responsible for this apnea remains unknown. We tested whether intralaryngeal (local) application of FNT would also trigger an apnea and whether the apneic response to both local and systemic administration of FNT was laryngeal afferent-mediated. Cardiorespiratory responses to FNT were recorded in anesthetized male adult rats with and without bilateral sectioning of the superior laryngeal nerve (SLNx) or peri-SLN capsaicin treatment (SLNcap) to block local C-fiber signal conduction. Opioid mu-receptor (MOR)-immunoreactivity was detected in laryngeal C- and myelinated neurons. We found that local and systemic administration of FNT elicited an immediate apnea. SLNx, rather than SLNcap, abolished the apneic response to local FNT application though MORs were abundantly expressed in both laryngeal C- and myelinated neurons. Importantly, SLNx failed to affect the apneic response to systemic FNT administration. These results lead to the conclusion that laryngeal afferents' MORs are responsible for the apneic response to local, but not systemic, administration of FNT.
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Affiliation(s)
- Jianguo Zhuang
- Department of PhysiologyLovelace Biomedical Research InstituteAlbuquerqueNew MexicoUSA
| | - Xiuping Gao
- Department of PhysiologyLovelace Biomedical Research InstituteAlbuquerqueNew MexicoUSA
| | - Shan Shi
- Department of PhysiologyLovelace Biomedical Research InstituteAlbuquerqueNew MexicoUSA
| | - Fadi Xu
- Department of PhysiologyLovelace Biomedical Research InstituteAlbuquerqueNew MexicoUSA
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2
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Abstract
Coughing is a dynamic physiological process resulting from input of vagal sensory neurons innervating the airways and perceived airway irritation. Although cough serves to protect and clear the airways, it can also be exploited by respiratory pathogens to facilitate disease transmission. Microbial components or infection-induced inflammatory mediators can directly interact with sensory nerve receptors to induce a cough response. Analysis of cough-generated aerosols and transmission studies have further demonstrated how infectious disease is spread through coughing. This review summarizes the neurophysiology of cough, cough induction by respiratory pathogens and inflammation, and cough-mediated disease transmission.
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Affiliation(s)
- Kubra F Naqvi
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, University of Melbourne, Victoria, Australia
| | - Michael U Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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3
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Tkachenko Y, Khmyz V, Isaev D, Maximyuk O, Krishtal O. Temperature increase significantly enhances nociceptive responses of C-fibers to ATP, high K +, and acidic pH in mice. Front Cell Neurosci 2023; 17:1131643. [PMID: 36846206 PMCID: PMC9948025 DOI: 10.3389/fncel.2023.1131643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 01/26/2023] [Indexed: 02/11/2023] Open
Abstract
It is well established that temperature affects the functioning of almost all biomolecules and, consequently, all cellular functions. Here, we show how temperature variations within a physiological range affect primary afferents' spontaneous activity in response to chemical nociceptive stimulation. An ex vivo mouse hind limb skin-saphenous nerve preparation was used to study the temperature dependence of single C-mechanoheat (C-MH) fibers' spontaneous activity. Nociceptive fibers showed a basal spike frequency of 0.097 ± 0.013 Hz in control conditions (30°C). Non-surprisingly, this activity decreased at 20°C and increased at 40°C, showing moderate temperature dependence with Q10∼2.01. The fibers' conduction velocity was also temperature-dependent, with an apparent Q10 of 1.38. Both Q10 for spike frequency and conduction velocity were found to be in good correspondence with an apparent Q10 for ion channels gating. Then we examined the temperature dependence of nociceptor responses to high K+, ATP, and H+. Receptive fields of nociceptors were superfused with solutions containing 10.8 mM K+, 200 μM ATP, and H+ (pH 6.7) at three different temperatures: 20, 30, and 40°C. We found that at 30 and 20°C, all the examined fibers were sensitive to K+, but not to ATP or H+. At 20°C, only 53% of fibers were responsible for ATP; increasing the temperature to 40°C resulted in 100% of sensitive fibers. Moreover, at 20°C, all observed fibers were silent to pH, but at 40°C, this number was gradually increased to 87.9%. We have found that the temperature increase from 20 to 30°C significantly facilitated responses to ATP (Q10∼3.11) and H+ (Q10∼3.25), leaving high K+ virtually untouched (Q10∼1.88 vs. 2.01 in control conditions). These data suggest a possible role of P2X receptors in coding the intensity of non-noxious thermal stimuli.
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Affiliation(s)
| | - Volodymyr Khmyz
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Dmytro Isaev
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Oleksandr Maximyuk
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Oleg Krishtal
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
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Sykes DL, Zhang M, Morice AH. Treatment of chronic cough: P2X3 receptor antagonists and beyond. Pharmacol Ther 2022; 237:108166. [DOI: 10.1016/j.pharmthera.2022.108166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/22/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
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Pathophysiology of Airway Afferent Nerves. ACTA MEDICA MARTINIANA 2022. [DOI: 10.2478/acm-2022-0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract
Vagal afferent nerves provide an airway defense mechanism which is ensured by their activation. These nerves can be activated mechanically mainly through mechanosensitive Aβ fibers which are divided into slowly adapting (SARs) and rapidly adapting stretch receptors (RARs). Chemical activation is provided by an interaction of chemical substances with specific receptors. C-fibers are highly sensitive to a direct chemical stimulation accomplished by an activation of ligand-gated ion channels. According to the large influence and mechanisms of vagal afferent nerves, there is a probability that an inappropriate activity of these nerves can cause the symptoms of the respiratory diseases, e.g. cough, dyspnoea, or airway hyperreactivity. The aim of this review is to summarize the physiology of airway afferent nerves and point out the role of vagal sensory nerves dysfunction in the pathogenesis of some respiratory diseases. The understanding of its mechanism could lead to new therapeutic strategies in patients with airway-related pathology.
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Capsaicin and TRPV1 Channels in the Cardiovascular System: The Role of Inflammation. Cells 2021; 11:cells11010018. [PMID: 35011580 PMCID: PMC8750852 DOI: 10.3390/cells11010018] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 12/24/2022] Open
Abstract
Capsaicin is a potent agonist of the Transient Receptor Potential Vanilloid type 1 (TRPV1) channel and is a common component found in the fruits of the genus Capsicum plants, which have been known to humanity and consumed in food for approximately 7000-9000 years. The fruits of Capsicum plants, such as chili pepper, have been long recognized for their high nutritional value. Additionally, capsaicin itself has been proposed to exhibit vasodilatory, antimicrobial, anti-cancer, and antinociceptive properties. However, a growing body of evidence reveals a vasoconstrictory potential of capsaicin acting via the vascular TRPV1 channel and suggests that unnecessary high consumption of capsaicin may cause severe consequences, including vasospasm and myocardial infarction in people with underlying inflammatory conditions. This review focuses on vascular TRPV1 channels that are endogenously expressed in both vascular smooth muscle and endothelial cells and emphasizes the role of inflammation in sensitizing the TRPV1 channel to capsaicin activation. Tilting the balance between the beneficial vasodilatory action of capsaicin and its unwanted vasoconstrictive effects may precipitate adverse outcomes such as vasospasm and myocardial infarction, especially in the presence of proinflammatory mediators.
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Rouadi PW, Idriss SA, Bousquet J, Laidlaw TM, Azar CR, Sulaiman AL-Ahmad M, Yáñez A, AL-Nesf MAY, Nsouli TM, Bahna SL, Abou-Jaoude E, Zaitoun FH, Hadi UM, Hellings PW, Scadding GK, Smith PK, Morais-Almeida M, Gómez RM, González Díaz SN, Klimek L, Juvelekian GS, Riachy MA, Canonica GW, Peden D, Wong GW, Sublett J, Bernstein JA, Wang L, Tanno LK, Chikhladze M, Levin M, Chang YS, Martin BL, Caraballo L, Custovic A, Ortega-Martell JA, Jensen-Jarolim E, Ebisawa M, Fiocchi A, Ansotegui IJ. WAO-ARIA consensus on chronic cough - Part 1: Role of TRP channels in neurogenic inflammation of cough neuronal pathways. World Allergy Organ J 2021; 14:100617. [PMID: 34934475 PMCID: PMC8654622 DOI: 10.1016/j.waojou.2021.100617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Cough features a complex peripheral and central neuronal network. The function of the chemosensitive and stretch (afferent) cough receptors is well described but partly understood. It is speculated that chronic cough reflects a neurogenic inflammation of the cough reflex, which becomes hypersensitive. This is mediated by neuromediators, cytokines, inflammatory cells, and a differential expression of neuronal (chemo/stretch) receptors, such as transient receptor potential (TRP) and purinergic P2X ion channels; yet the overall interaction of these mediators in neurogenic inflammation of cough pathways remains unclear. OBJECTIVES The World Allergy Organization/Allergic Rhinitis and its Impact on Asthma (WAO/ARIA) Joint Committee on Chronic Cough reviewed the current literature on neuroanatomy and pathophysiology of chronic cough. The role of TRP ion channels in pathogenic mechanisms of the hypersensitive cough reflex was also examined. OUTCOMES Chemoreceptors are better studied in cough neuronal pathways compared to stretch receptors, likely due to their anatomical overabundance in the respiratory tract, but also their distinctive functional properties. Central pathways are important in suppressive mechanisms and behavioral/affective aspects of chronic cough. Current evidence strongly suggests neurogenic inflammation induces a hypersensitive cough reflex marked by increased expression of neuromediators, mast cells, and eosinophils, among others. TRP ion channels, mainly TRP V1/A1, are important in the pathogenesis of chronic cough due to their role in mediating chemosensitivity to various endogenous and exogenous triggers, as well as a crosstalk between neurogenic and inflammatory pathways in cough-associated airways diseases.
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Affiliation(s)
- Philip W. Rouadi
- Department of Otolaryngology - Head and Neck Surgery, Eye and Ear University Hospital, Beirut, Lebanon
| | - Samar A. Idriss
- Department of Otolaryngology - Head and Neck Surgery, Eye and Ear University Hospital, Beirut, Lebanon
- Department of Audiology and Otoneurological Evaluation, Edouard Herriot Hospital, Lyon, France
| | - Jean Bousquet
- Hospital Charité, Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Dermatology and Allergy, Comprehensive Allergy Center, Berlin Institute of Health, Berlin, Germany
- Macvia France, Montpellier France
- Université Montpellier, Montpellier, France
| | - Tanya M. Laidlaw
- Department of Medicine, Harvard Medical School, Division of Allergy and Clinical Immunology, Brigham and Women's Hospital Boston, MA, USA
| | - Cecilio R. Azar
- Department of Gastroenterology, American University of Beirut Medical Center (AUBMC), Beirut, Lebanon
- Department of Gastroenterology, Middle East Institute of Health (MEIH), Beirut, Lebanon
- Department of Gastroenterology, Clemenceau Medical Center (CMC), Beirut, Lebanon
| | | | - Anahí Yáñez
- INAER - Investigaciones en Alergia y Enfermedades Respiratorias, Buenos Aires, Argentina
| | - Maryam Ali Y. AL-Nesf
- Allergy and Immunology Section, Department of Medicine, Hamad Medical Corporation, P.O. Box 3050, Doha, Qatar
| | | | - Sami L. Bahna
- Allergy & Immunology Section, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | | | - Fares H. Zaitoun
- Department of Allergy Otolaryngology, LAU-RIZK Medical Center, Beirut, Lebanon
| | - Usamah M. Hadi
- Clinical Professor Department of Otolaryngology Head and Neck Surgery, American University of Beirut, Lebanon
| | - Peter W. Hellings
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Allergy and Clinical Immunology, Leuven, Belgium
- University Hospitals Leuven, Department of Otorhinolaryngology, Leuven, Belgium
- University Hospital Ghent, Department of Otorhinolaryngology, Laboratory of Upper Airways Research, Ghent, Belgium
- Academic Medical Center, University of Amsterdam, Department of Otorhinolaryngology, Amsterdam, the Netherlands
| | | | - Peter K. Smith
- Clinical Medicine Griffith University, Southport Qld, 4215, Australia
| | | | | | - Sandra N. González Díaz
- Universidad Autónoma de Nuevo León, Hospital Universitario and Facultad de Medicina, Monterrey, Nuevo León, Mexico
| | - Ludger Klimek
- Center for Rhinology and Allergology, Wiesbaden, Germany
| | - Georges S. Juvelekian
- Department of Pulmonary, Critical Care and Sleep Medicine at Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Moussa A. Riachy
- Department of Pulmonary and Critical Care, Hôtel-Dieu de France University Hospital, Beirut, Lebanon
| | - Giorgio Walter Canonica
- Humanitas University, Personalized Medicine Asthma & Allergy Clinic-Humanitas Research Hospital-IRCCS-Milano Italy
| | - David Peden
- UNC Center for Environmental Medicine, Asthma, and Lung Biology, Division of Allergy, Immunology and Rheumatology, Department of Pediatrics UNS School of Medicine, USA
| | - Gary W.K. Wong
- Department of Pediatrics, Chinese University of Hong Kong, Hong Kong, China
| | - James Sublett
- Department of Pediatrics, Section of Allergy and Immunology, University of Louisville School of Medicine, 9800 Shelbyville Rd, Louisville, KY, USA
| | - Jonathan A. Bernstein
- University of Cincinnati College of Medicine, Department of Internal Medicine, Division of Immunology/Allergy Section, Cincinnati
| | - Lianglu Wang
- Department of Allergy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment of Allergic Disease, State Key Laboratory of Complex Severe and Rare Diseases, National Clinical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID), Beijing 100730, China
| | - Luciana Kase Tanno
- Université Montpellier, Montpellier, France
- Desbrest Institute of Epidemiology and Public Health, UMR UA-11, INSERM University of Montpellier, Montpellier, France
- WHO Collaborating Centre on Scientific Classification Support, Montpellier, France
| | - Manana Chikhladze
- Medical Faculty at Akaki Tsereteli State University, National Institute of Allergy, Asthma & Clinical Immunology, KuTaisi, Tskaltubo, Georgia
| | - Michael Levin
- Division of Paediatric Allergology, Department of Paediatrics, University of Cape Town, South Africa
| | - Yoon-Seok Chang
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Bryan L. Martin
- Department of Otolaryngology, Division of Allergy & Immunology, The Ohio State University, Columbus, OH, USA
| | - Luis Caraballo
- Institute for Immunological Research, University of Cartagena. Cartagena de Indias, Colombia
| | - Adnan Custovic
- National Heart and Lund Institute, Imperial College London, UK
| | | | - Erika Jensen-Jarolim
- Institute of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University Vienna, Austria
- The Interuniversity Messerli Research Institute, Medical University Vienna and Univ, of Veterinary Medicine Vienna, Austria
| | - Motohiro Ebisawa
- Clinical Research Center for Allergy and Rheumatology,National Hospital Organization Sagamihara National Hospital, Sagamihara, Japan
| | - Alessandro Fiocchi
- Translational Pediatric Research Area, Allergic Diseases Research Unit, Bambino Gesù Children's Hospital IRCCS, Rome, Holy See
| | - Ignacio J. Ansotegui
- Department of Allergy and Immunology, Hospital Quironsalud Bizkaia, Bilbao, Spain
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The Changes in Expression of Na V1.7 and Na V1.8 and the Effects of the Inhalation of Their Blockers in Healthy and Ovalbumin-Sensitized Guinea Pig Airways. MEMBRANES 2021; 11:membranes11070511. [PMID: 34357161 PMCID: PMC8304019 DOI: 10.3390/membranes11070511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 07/01/2021] [Accepted: 07/03/2021] [Indexed: 01/06/2023]
Abstract
Background: The presented study evaluated the suppositional changes in the airway expression of Nav1.8 and Nav1.7 and their role in the airway defense mechanisms in healthy animals and in an experimental asthma model. Methods: The effects of the blockers inhalation on the reactivity of guinea pig airways, number of citric-acid-induced coughs and ciliary beating frequency (CBF) were tested in vivo. Chronic inflammation simulating asthma was induced by repetitive exposure to ovalbumin. The expression of Nav1.7 and Nav1.8 was examined by ELISA. Results: The Nav 1.8 blocker showed complex antitussive and bronchodilatory effects and significantly regulated the CBF in healthy and sensitized animals. The Nav1.7 blockers significantly inhibited coughing and participated in CBF control in the ovalbumin-sensitized animals. The increased expression of the respective ion channels in the sensitized animals corresponded to changes in CBF regulation. The therapeutic potency of the Nav1.8 blocker was evidenced in combinations with classic bronchodilators. Conclusion: The allergic-inflammation-upregulated expression of Nav1.7 and Nav1.8 and corresponding effects of blocker inhalation on airway defense mechanisms, along with the Nav1.8 blocker’s compatibility with classic antiasthmatic drugs, bring novel possibilities for the treatment of various respiratory diseases. However, the influence of the Nav1.8 blocker on CBF requires further investigation.
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Infection-Associated Mechanisms of Neuro-Inflammation and Neuro-Immune Crosstalk in Chronic Respiratory Diseases. Int J Mol Sci 2021; 22:ijms22115699. [PMID: 34071807 PMCID: PMC8197882 DOI: 10.3390/ijms22115699] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic obstructive airway diseases are characterized by airflow obstruction and airflow limitation as well as chronic airway inflammation. Especially bronchial asthma and chronic obstructive pulmonary disease (COPD) cause considerable morbidity and mortality worldwide, can be difficult to treat, and ultimately lack cures. While there are substantial knowledge gaps with respect to disease pathophysiology, our awareness of the role of neurological and neuro-immunological processes in the development of symptoms, the progression, and the outcome of these chronic obstructive respiratory diseases, is growing. Likewise, the role of pathogenic and colonizing microorganisms of the respiratory tract in the development and manifestation of asthma and COPD is increasingly appreciated. However, their role remains poorly understood with respect to the underlying mechanisms. Common bacteria and viruses causing respiratory infections and exacerbations of chronic obstructive respiratory diseases have also been implicated to affect the local neuro-immune crosstalk. In this review, we provide an overview of previously described neuro-immune interactions in asthma, COPD, and respiratory infections that support the hypothesis of a neuro-immunological component in the interplay between chronic obstructive respiratory diseases, respiratory infections, and respiratory microbial colonization.
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Brozmanova M, Pavelkova N. The Prospect for Potent Sodium Voltage-Gated Channel Blockers to Relieve an Excessive Cough. Physiol Res 2021; 69:S7-S18. [PMID: 32228007 DOI: 10.33549/physiolres.934395] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
An excessive, irritable, productive or non-productive coughing associated with airway inflammation belongs to pathological cough. Increased activation of airway vagal nociceptors in pathological conditions results from dysregulation of the neural pathway that controls cough. A variety of mediators associated with airway inflammation overstimulate these vagal airway fibers including C-fibers leading to hypersensitivity and hyperreactivity. Because current antitussives have limited efficacy and unwanted side effects there is a continual demand for the development of a novel more effective antitussives for a new efficacious and safe cough treatment. Therefore, inhibiting the activity of these vagal C-fibers represents a rational approach to the development of effective antitussive drugs. This may be achieved by blocking inflammatory mediator receptors or by blocking the generator potential associated with the specific ion channels. Because voltage-gated sodium channels (NaVs) are absolutely required for action potentials initiation and conduction irrespective of the stimulus, NaVs become a promising neural target. There is evidence that NaV1.7, 1.8 and 1.9 subtypes are predominantly expressed in airway cough-triggering nerves. The advantage of blocking these NaVs is suppressing C-fiber irrespective to stimuli, but the disadvantage is that by suppressing the nerves is may also block beneficial sensations and neuronal reflex behavior. The concept is that new antitussive drugs would have the benefit of targeting peripheral airway nociceptors without inhibiting the protective cough reflex.
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Affiliation(s)
- M Brozmanova
- Department of Pathophysiology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia.
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Singh N, Driessen AK, McGovern AE, Moe AAK, Farrell MJ, Mazzone SB. Peripheral and central mechanisms of cough hypersensitivity. J Thorac Dis 2020; 12:5179-5193. [PMID: 33145095 PMCID: PMC7578480 DOI: 10.21037/jtd-2020-icc-007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chronic cough is a difficult to treat symptom of many respiratory and some non-respiratory diseases, indicating that varied pathologies can underpin the development of chronic cough. However, clinically and experimentally it has been useful to collate these different pathological processes into the single unifying concept of cough hypersensitivity. Cough hypersensitivity syndrome is reflected by troublesome cough often precipitated by levels of stimuli that ordinarily don't cause cough in healthy people, and this appears to be a hallmark feature in many patients with chronic cough. Accordingly, a strong argument has emerged that changes in the excitability and/or normal regulation of the peripheral and central neural circuits responsible for cough are instrumental in establishing cough hypersensitivity and for causing excessive cough in disease. In this review, we explore the current peripheral and central neural mechanisms that are believed to be involved in altered cough sensitivity and present possible links to the mechanism of action of novel therapies that are currently undergoing clinical trials for chronic cough.
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Affiliation(s)
- Nabita Singh
- Department of Medical Imaging and Radiation Sciences, Monash University, Clayton, Australia
| | - Alexandria K. Driessen
- Department of Anatomy and Neuroscience, School of Biomedical Science, The University of Melbourne, Parkville, Australia
| | - Alice E. McGovern
- Department of Anatomy and Neuroscience, School of Biomedical Science, The University of Melbourne, Parkville, Australia
| | - Aung Aung Kywe Moe
- Department of Anatomy and Neuroscience, School of Biomedical Science, The University of Melbourne, Parkville, Australia
| | - Michael J. Farrell
- Department of Medical Imaging and Radiation Sciences, Monash University, Clayton, Australia
- Monash Biomedical Imaging, Monash University, Clayton, Australia
| | - Stuart B. Mazzone
- Department of Anatomy and Neuroscience, School of Biomedical Science, The University of Melbourne, Parkville, Australia
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12
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Wallace E, Guiu Hernandez E, Epton M, Ploen L, Huckabee ML, Macrae P. A Sensory Stimulation Protocol to Modulate Cough Sensitivity: A Randomized Controlled Trial Safety Study. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2020; 29:1423-1433. [PMID: 32379483 DOI: 10.1044/2020_ajslp-19-00180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose This study evaluated the safety and efficacy of a sensory stimulation protocol that was designed to modulate citric acid cough thresholds as a potential treatment for silent aspiration. Method Healthy adults (n = 24) were randomly assigned to one of three sensory stimulation groups: (a) high-intensity ultrasonically nebulized distilled water (UNDW) inhalations (1.6 ml/min); (b) low-intensity UNDW inhalations (0.5 ml/min); and (3) control, 0.9% saline inhalations (1.6 ml/min). Sensory stimulation was delivered once a day, for 4 consecutive days. Citric acid cough thresholds were determined at baseline, Day 3, and Day 5 to evaluate changes in cough sensitivity. Spirometry was undertaken before, during, and after each sensory stimulation session to monitor for bronchoconstriction. Results No participant showed evidence of bronchoconstriction during the sensory stimulation protocol. There was an interaction effect between day and group on suppressed cough thresholds, χ2(4) = 11.32, p = .02. When compared to the control group, there was a decrease in citric acid cough thresholds across Days 1-5 in the high-intensity (-1.8 doubling concentrations, 95% confidence interval [-2.88, -0.72], p = .01) and low-intensity (-1.3 doubling concentrations, 95% confidence interval [-2.4, -0.2], p = .03) UNDW inhalation groups, representing a sensitization effect of UNDW inhalations on cough sensitivity. Conclusions The UNDW sensory stimulation protocol was safe in healthy adults. The findings provide preliminary evidence that UNDW inhalations sensitize laryngeal afferents related to citric acid-induced cough induction. The therapeutic potential of the UNDW sensory stimulation protocol will be explored in patients with reduced cough sensitivity who are at risk of silent aspiration and aspiration pneumonia. Plain Language Summary This study explored the safety and efficacy of a sensory stimulation protocol that was designed to modulate cough sensitivity as a potential treatment for silent aspiration. The study revealed that inhalations of nebulized distilled water were safe and increased cough sensitivity, when compared to control saline inhalations.
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Affiliation(s)
- Emma Wallace
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Esther Guiu Hernandez
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Michael Epton
- Canterbury Respiratory Research Group, Christchurch Hospital, New Zealand
| | - Laura Ploen
- Respiratory Physiology Laboratory, Christchurch Hospital, New Zealand
| | - Maggie-Lee Huckabee
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Phoebe Macrae
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
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Kupari J, Häring M, Agirre E, Castelo-Branco G, Ernfors P. An Atlas of Vagal Sensory Neurons and Their Molecular Specialization. Cell Rep 2020; 27:2508-2523.e4. [PMID: 31116992 PMCID: PMC6533201 DOI: 10.1016/j.celrep.2019.04.096] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/25/2019] [Accepted: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
Sensory functions of the vagus nerve are critical for conscious perceptions and for monitoring visceral functions in the cardio-pulmonary and gastrointestinal systems. Here, we present a comprehensive identification, classification, and validation of the neuron types in the neural crest (jugular) and placode (nodose) derived vagal ganglia by single-cell RNA sequencing (scRNA-seq) transcriptomic analysis. Our results reveal major differences between neurons derived from different embryonic origins. Jugular neurons exhibit fundamental similarities to the somatosensory spinal neurons, including major types, such as C-low threshold mechanoreceptors (C-LTMRs), A-LTMRs, Aδ-nociceptors, and cold-, and mechano-heat C-nociceptors. In contrast, the nodose ganglion contains 18 distinct types dedicated to surveying the physiological state of the internal body. Our results reveal a vast diversity of vagal neuron types, including many previously unanticipated types, as well as proposed types that are consistent with chemoreceptors, nutrient detectors, baroreceptors, and stretch and volume mechanoreceptors of the respiratory, gastrointestinal, and cardiovascular systems. A comprehensive molecular identification of neuronal types in vagal ganglion complex Prdm12+ jugular ganglion neurons share features with spinal somatosensory neurons Phox2b+ viscerosensory nodose neurons are molecularly versatile and highly specialized Nodose neuron types are consistent with chemo-, baro-, stretch-, tension-, and volume-sensors
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Affiliation(s)
- Jussi Kupari
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Häring
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Eneritz Agirre
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Gonçalo Castelo-Branco
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Patrik Ernfors
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden.
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14
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Prescott SL, Umans BD, Williams EK, Brust RD, Liberles SD. An Airway Protection Program Revealed by Sweeping Genetic Control of Vagal Afferents. Cell 2020; 181:574-589.e14. [PMID: 32259485 PMCID: PMC7197391 DOI: 10.1016/j.cell.2020.03.004] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/08/2020] [Accepted: 03/04/2020] [Indexed: 12/22/2022]
Abstract
Sensory neurons initiate defensive reflexes that ensure airway integrity. Dysfunction of laryngeal neurons is life-threatening, causing pulmonary aspiration, dysphagia, and choking, yet relevant sensory pathways remain poorly understood. Here, we discover rare throat-innervating neurons (∼100 neurons/mouse) that guard the airways against assault. We used genetic tools that broadly cover a vagal/glossopharyngeal sensory neuron atlas to map, ablate, and control specific afferent populations. Optogenetic activation of vagal P2RY1 neurons evokes a coordinated airway defense program-apnea, vocal fold adduction, swallowing, and expiratory reflexes. Ablation of vagal P2RY1 neurons eliminates protective responses to laryngeal water and acid challenge. Anatomical mapping revealed numerous laryngeal terminal types, with P2RY1 neurons forming corpuscular endings that appose laryngeal taste buds. Epithelial cells are primary airway sentinels that communicate with second-order P2RY1 neurons through ATP. These findings provide mechanistic insights into airway defense and a general molecular/genetic roadmap for internal organ sensation by the vagus nerve.
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Affiliation(s)
- Sara L Prescott
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Benjamin D Umans
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Erika K Williams
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Rachael D Brust
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen D Liberles
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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15
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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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16
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Demoulin B, Coutier-Marie L, Ioan I, Schweitzer CE, Foucauld L, Demoulin-Alexikova S. In Vivo Documentation of Stimulus Velocity Tuning of Mechanically Induced Reflex Cough. Physiol Res 2020; 69:S139-S145. [PMID: 32228019 DOI: 10.33549/physiolres.934397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In order to clear airways and lungs defensive reflexes are provoked rather by the dynamic phase of mechanical stimulus. It is speculated that provocation of defensive response depends not only on stimulus duration but also on stimulus velocity. Fourteen adult rabbits were anaesthetized and tracheotomized. Mechanical stimulus was provoked by a mechanical probe introduced through the tracheotomy and rotated by a small electrical motor using a rotational velocity of 40 rpm/s and 20 rpm/s. Threshold, incidence and intensity of cough reflex (CR) were analyzed for each animal. Statistical comparisons between two velocities were performed using Friedman nonparametric test for repeated measurements. Results are median (25-75 %). The threshold of CR was significantly increased (p=0.005) from 350 ms (300-500 ms) to 550 ms (350-1150 ms) and the incidence of cough reflex was significantly reduced (p=0.002) from 50 % (19 50 %) to 0 % (0-25 %) when the rotational velocity of the mechanical probe was reduced by half. The findings of this study are of interest as they show that protective reflex cough, an important mechanism that allows clearing airways even during sleep or anesthesia, is tuned by mechanical stimulus velocity.
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Affiliation(s)
- B Demoulin
- Research Unit EA 3450 DevAH-Development, Adaptation and Handicap, Campus Biologie Santé, University of Lorraine, Vandoeuvre-les-Nancy,
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17
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Liao YSJ, Kuan SP, Guevara MV, Collins EN, Atanasova KR, Dadural JS, Vogt K, Schurmann V, Bravo L, Eken E, Sponchiado M, Reznikov LR. Acid exposure disrupts mucus secretion and impairs mucociliary transport in neonatal piglet airways. Am J Physiol Lung Cell Mol Physiol 2020; 318:L873-L887. [PMID: 32160007 DOI: 10.1152/ajplung.00025.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Tenacious mucus produced by tracheal and bronchial submucosal glands is a defining feature of several airway diseases, including cystic fibrosis (CF). Airway acidification as a driving force of CF airway pathology has been controversial. Here we tested the hypothesis that transient airway acidification produces pathologic mucus and impairs mucociliary transport. We studied pigs challenged with intra-airway acid. Acid had a minimal effect on mucus properties under basal conditions. However, cholinergic stimulation in acid-challenged pigs revealed retention of mucin 5B (MUC5B) in the submucosal glands, decreased concentrations of MUC5B in the lung lavage fluid, and airway obstruction. To more closely mimic a CF-like environment, we also examined mucus secretion and transport following cholinergic stimulation under diminished bicarbonate and chloride transport conditions ex vivo. Under these conditions, airways from acid-challenged pigs displayed extensive mucus films and decreased mucociliary transport. Pretreatment with diminazene aceturate, a small molecule with ability to inhibit acid detection through blockade of the acid-sensing ion channel (ASIC) at the doses provided, did not prevent acid-induced pathologic mucus or transport defects but did mitigate airway obstruction. These findings suggest that transient airway acidification early in life has significant impacts on mucus secretion and transport properties. Furthermore, they highlight diminazene aceturate as an agent that might be beneficial in alleviating airway obstruction.
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Affiliation(s)
- Yan Shin J Liao
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Shin Ping Kuan
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Maria V Guevara
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Emily N Collins
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Kalina R Atanasova
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Joshua S Dadural
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Kevin Vogt
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Veronica Schurmann
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Laura Bravo
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Eda Eken
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Mariana Sponchiado
- Department of Physiological Sciences University of Florida, Gainesville, Florida
| | - Leah R Reznikov
- Department of Physiological Sciences University of Florida, Gainesville, Florida
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18
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Lin AH, Hsu CC, Lin YS, Lin RL, Lee LY. Mechanisms underlying the stimulatory effect of inhaled sulfur dioxide on vagal bronchopulmonary C-fibres. J Physiol 2020; 598:1093-1108. [PMID: 31891193 DOI: 10.1113/jp279152] [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: 10/19/2019] [Accepted: 12/29/2019] [Indexed: 02/05/2023] Open
Abstract
KEY POINTS Brief inhalation of SO2 of concentration >500 p.p.m. triggered a pronounced stimulatory effect on vagal bronchopulmonary C-fibres in anaesthetized rats. This stimulatory effect was drastically diminished by a pretreatment with NaHCO3 that raised the baseline arterial pH, suggesting a possible involvement of acidification of airway fluid and/or tissue generated by inhaled SO2 . The stimulation was completely abolished by pretreatment with antagonists of both acid-sensing ion channels and transient receptor potential vanilloid type-1 receptors, indicating that this effect was caused by acid activation of these cation channels expressed in airway sensory nerves. This conclusion was further supported by the results obtained from studies in isolated rat vagal bronchopulmonary sensory neurones and also in the cough response to SO2 inhalation challenge in awake mice. These results provide new insight into the underlying mechanism of harmful irritant effects in the respiratory tract caused by accidental exposure to a high concentration of SO2 . ABSTRACT Inhalation of sulfur dioxide (SO2 ) triggers coughs and reflex bronchoconstriction, and stimulation of vagal bronchopulmonary C-fibres is primarily responsible. However, the mechanism underlying this stimulatory effect is not yet fully understood. In this study, we tested the hypothesis that the C-fibre stimulation was caused by SO2 -induced local tissue acidosis in the lung and airways. Single-unit activities of bronchopulmonary C-fibres in response to inhalation challenges of SO2 (500-1500 p.p.m., 10 breaths) were measured in anaesthetized rats. Inhalation of SO2 reproducibly induced a pronounced and sustained stimulation (lasting for 15-60 s) of pulmonary C-fibres in a concentration-dependent manner. This stimulatory effect was significantly attenuated by an increase in arterial pH generated by infusion of sodium bicarbonate (NaHCO3 ), and completely abrogated by a combined pretreatment with amiloride (an antagonist of acid-sensing ion channels, ASICs) and AMG8910 (a selective antagonist of the transient receptor potential vanilloid type-1 receptor, TRPV1). Furthermore, in isolated rat vagal pulmonary sensory neurones, perfusion of an aqueous solution of SO2 evoked a transient increase in the intracellular Ca2+ concentration; this response was also markedly diminished by a pretreatment with amiloride and AMG8910. In addition, inhalation of SO2 consistently evoked coughs in awake mice; responses were significantly smaller in TRPV1-/- mice than in wild-type mice, and almost completely abolished after a pretreatment with amiloride in TRPV1-/- mice. These results suggested that the stimulatory effect of inhaled SO2 on bronchopulmonary C-fibres was generated by acidification of fluid and/or tissue in the lung and airways, which activated both ASICs and TRPV1 expressed in these sensory nerves.
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Affiliation(s)
- An-Hsuan Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
| | - Chun-Chun Hsu
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA.,School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - You Shuei Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ruei-Lung Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
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19
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Undem BJ, Sun H. Molecular/Ionic Basis of Vagal Bronchopulmonary C-Fiber Activation by Inflammatory Mediators. Physiology (Bethesda) 2020; 35:57-68. [PMID: 31799905 PMCID: PMC6985783 DOI: 10.1152/physiol.00014.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/30/2019] [Accepted: 06/03/2019] [Indexed: 12/11/2022] Open
Abstract
Stimulation of bronchopulmonary vagal afferent C fibers by inflammatory mediators can lead to coughing, chest tightness, and changes in breathing pattern, as well as reflex bronchoconstriction and secretions. These responses serve a defensive function in healthy lungs but likely contribute to many of the signs and symptoms of inflammatory airway diseases. A better understanding of the mechanisms underlying the activation of bronchopulmonary C-fiber terminals may lead to novel therapeutics that would work in an additive or synergic manner with existing anti-inflammatory strategies.
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Affiliation(s)
| | - Hui Sun
- Johns Hopkins University, Baltimore, Maryland
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20
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Wei W, Gao X, Zhao L, Zhuang J, Jiao Y, Xu F. Liquiritin apioside attenuates laryngeal chemoreflex but not mechanoreflex in rat pups. Am J Physiol Lung Cell Mol Physiol 2020; 318:L89-L97. [PMID: 31617735 PMCID: PMC6985871 DOI: 10.1152/ajplung.00306.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 02/08/2023] Open
Abstract
Liquiritin apioside (LA), a main flavonoid component of licorice, reportedly suppresses cough responses to inhalation of aerosolized capsaicin [CAP; a stimulant to transient receptor potential vanilloid 1 (TRPV1)] in conscious guinea pigs via acting on peripheral nerves. However, the evidence of LA having a direct effect on airway sensory fibers is lacking. Considering the important role laryngeal chemoreceptors and mechanoreceptors play in triggering apnea and cough, we studied whether LA suppressed the apneic responses to stimulation of these receptors via directly acting on the superior laryngeal nerve (SLN). Intralaryngeal delivery of chemical [CAP, HCl, and distilled water (DW)] and mechanical [an air-pulse (AP)] stimulations was applied in anesthetized rat pups to evoke the apnea. These stimuli were repeated after intralaryngeal LA treatment or peri-SLN LA treatment to determine the direct effect of LA on the SLN. Our results showed that all stimuli triggered an immediate apnea. Intralaryngeal LA treatment significantly attenuated the apneic response to chemical but not mechanical stimulations. The same attenuation was observed after peri-SLN LA treatment. Owing that TRPV1 receptors of laryngeal C fibers are responsible for the CAP-triggered apneas, the LA impact on the activity of laryngeal C neurons retrogradely traced by DiI was subsequently studied using a patch-clamp approach. LA pretreatment significantly altered the electrophysiological kinetics of CAP-induced currents in laryngeal C neurons by reducing their amplitudes, increasing the rise times, and prolonging the decay times. In conclusion, our results, for the first time, reveal that LA suppresses the laryngeal chemoreceptor-mediated apnea by directly acting on the SLN (TRPV1 receptors of laryngeal C fibers).
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Affiliation(s)
- Wan Wei
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Xiuping Gao
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Lei Zhao
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Jianguo Zhuang
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Yang Jiao
- Dongfang Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Fadi Xu
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
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21
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Transcriptional Profiling of Individual Airway Projecting Vagal Sensory Neurons. Mol Neurobiol 2019; 57:949-963. [DOI: 10.1007/s12035-019-01782-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/12/2019] [Indexed: 12/11/2022]
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22
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Wallace E, Guiu Hernandez E, Ang A, Macrae P. Quantifying test-retest variability of natural and suppressed citric acid cough thresholds and urge to cough ratings. Pulm Pharmacol Ther 2019; 58:101838. [DOI: 10.1016/j.pupt.2019.101838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 11/25/2022]
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23
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Wallace E, Guiu Hernandez E, Ang A, Hiew S, Macrae P. A systematic review of methods of citric acid cough reflex testing. Pulm Pharmacol Ther 2019; 58:101827. [PMID: 31326628 DOI: 10.1016/j.pupt.2019.101827] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION This systematic review summarises and appraises methods of citric acid cough reflex testing (CRT) documented in published literature. METHODS Electronic databases, MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus were searched up to and including 11th February 2018. Studies reporting a method of citric acid CRT, published in peer-reviewed journals in English or Spanish, were assessed for the inclusion criteria. Of the selected studies, information on the instrumentation and CRT protocol was extracted. RESULTS A total of 129 studies were included. Instrumentation and protocols differed widely across studies. Reporting of methods of citric acid CRT was sub-standard, with many crucial methodological components omitted from published manuscripts, preventing their full replication. CONCLUSIONS Considerable methodological variability exists for citric acid CRT in published literature. The findings suggest that caution is warranted in comparing citric acid cough thresholds across studies. Full replication of previously published methods of citric acid CRT is limited due to crucial elements of the citric acid CRT protocol being omitted from published manuscripts. These findings have implications on the use of citric acid CRT in clinical and pharmaceutical studies to evaluate the effects of antitussive medications and cough therapies.
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Affiliation(s)
- Emma Wallace
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand.
| | - Esther Guiu Hernandez
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Alicia Ang
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Sarah Hiew
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Phoebe Macrae
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
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24
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Methods of Cough Assessment. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2019; 7:1715-1723. [DOI: 10.1016/j.jaip.2019.01.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/24/2022]
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25
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Kollarik M, Sun H, Herbstsomer RA, Ru F, Kocmalova M, Meeker SN, Undem BJ. Different role of TTX-sensitive voltage-gated sodium channel (Na V 1) subtypes in action potential initiation and conduction in vagal airway nociceptors. J Physiol 2019; 596:1419-1432. [PMID: 29435993 DOI: 10.1113/jp275698] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/23/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The action potential initiation in the nerve terminals and its subsequent conduction along the axons of afferent nerves are not necessarily dependent on the same voltage-gated sodium channel (NaV 1) subunits. The action potential initiation in jugular C-fibres within airway tissues is not blocked by TTX; nonetheless, conduction of action potentials along the vagal axons of these nerves is often dependent on TTX-sensitive channels. This is not the case for nodose airway Aδ-fibres and C-fibres, where both action potential initiation and conduction is abolished by TTX or selective NaV 1.7 blockers. The difference between the initiation of action potentials within the airways vs. conduction along the axons should be considered when developing NaV 1 blocking drugs for topical application to the respiratory tract. ABSTRACT The action potential (AP) initiation in the nerve terminals and its subsequent AP conduction along the axons do not necessarily depend on the same subtypes of voltage-gated sodium channels (NaV 1s). We evaluated the role of TTX-sensitive and TTX-resistant NaV 1s in vagal afferent nociceptor nerves derived from jugular and nodose ganglia innervating the respiratory system. Single cell RT-PCR was performed on vagal afferent neurons retrogradely labelled from the guinea pig trachea. Almost all of the jugular neurons expressed the TTX-sensitive channel NaV 1.7 along with TTX-resistant NaV 1.8 and NaV 1.9. Tracheal nodose neurons also expressed NaV 1.7 but, less frequently, NaV 1.8 and NaV 1.9. NaV 1.6 were expressed in ∼40% of the jugular and 25% of nodose tracheal neurons. Other NaV 1 α subunits were only rarely expressed. Single fibre recordings were made from the vagal nodose and jugular nerve fibres innervating the trachea or lung in the isolated perfused vagally-innervated preparations that allowed for selective drug delivery to the nerve terminal compartment (AP initiation) or to the desheathed vagus nerve (AP conduction). AP initiation in jugular C-fibres was unaffected by TTX, although it was inhibited by NaV 1.8 blocker (PF-01247324) and abolished by combination of TTX and PF-01247324. However, AP conduction in the majority of jugular C-fibres was abolished by TTX. By contrast, both AP initiation and conduction in nodose nociceptors was abolished by TTX or selective NaV 1.7 blockers. Distinction between the effect of a drug with respect to inhibiting AP in the nerve terminals within the airways vs. at conduction sites along the vagus nerve is relevant to therapeutic strategies involving inhaled NaV 1 blocking drugs.
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Affiliation(s)
- M Kollarik
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pathophysiology, Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - H Sun
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - R A Herbstsomer
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - F Ru
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - M Kocmalova
- Department of Pharmacology, Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - S N Meeker
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - B J Undem
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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26
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Duricek M, Banovcin P, Halickova T, Hyrdel R, Kollarik M. Acidic Pharyngeal Reflux Does Not Correlate with Symptoms and Laryngeal Injury Attributed to Laryngopharyngeal Reflux. Dig Dis Sci 2019; 64:1270-1280. [PMID: 30430298 PMCID: PMC10694844 DOI: 10.1007/s10620-018-5372-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 11/08/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Laryngopharyngeal reflux (LPR) is suspected when the symptoms are attributed to the penetration of acidic gastroesophageal reflux (GER) into the larynx. However, the relationships between the intensity of LPR and symptoms and laryngeal injury have not been elucidated. Several factors confound the study of LPR, namely pH is monitored in the pharynx (pharyngeal reflux) but the pharyngeal acidity (pH) required to induce laryngeal injury is unknown, the GER origin of pharyngeal acid is not always established, and a recent treatment with proton pump inhibitors (PPI) confounds the analysis. AIMS We aimed to limit these confounding factors to analyze the relationship between LPR and symptoms and laryngeal injury. METHODS We used dual pharyngeal and distal esophageal 24-h pH/impedance monitoring to establish GER origin of pharyngeal reflux, we used an unbiased approach to analysis by evaluating a whole range of acidity (pH < 6, pH < 5.5, pH < 5.0, pH < 4.5 and pH < 4.0) in patients with suspected LPR without PPI for > 30 days. RESULTS Pharyngeal reflux was (median[IQR]) 14[8-20.5] and 4[1.5-6.5] pharyngeal reflux episodes with pH < 6.0 and pH < 5.5, respectively. Pharyngeal reflux with pH < 5.0 was rare. Comprehensive analysis did not reveal any correlation between symptoms (reflux symptom index) or laryngeal injury (reflux finding score) and the number of pharyngeal reflux episodes or duration of pharyngeal acid exposure at any pH level. CONCLUSION Unbiased comprehensive approach did not reveal any relationship between acidic pharyngeal reflux and the symptoms or laryngeal injury attributed to LPR. Limited clinical usefulness of pharyngeal monitoring reported by others is unlikely due to confounding factors.
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Affiliation(s)
- Martin Duricek
- Gastroenterology Clinic JFM CU, Jessenius Faculty of Medicine in Martin (JFM CU), Comenius University in Bratislava, Kollárova 2, 03659, Martin, Slovakia
| | - Peter Banovcin
- Gastroenterology Clinic JFM CU, Jessenius Faculty of Medicine in Martin (JFM CU), Comenius University in Bratislava, Kollárova 2, 03659, Martin, Slovakia.
| | - Tatiana Halickova
- Clinic of ENT and Head and Neck Surgery, Central Military and Faculty Hospital in Ružomberok, Považská 1380/2, 034 01, Ružomberok, Slovakia
| | - Rudolf Hyrdel
- Gastroenterology Clinic JFM CU, Jessenius Faculty of Medicine in Martin (JFM CU), Comenius University in Bratislava, Kollárova 2, 03659, Martin, Slovakia
| | - Marian Kollarik
- Department of Pathophysiology JFM CU, Jessenius Faculty of Medicine in Martin (JFM CU), Comenius University in Bratislava, Ružomberok, Slovakia
- Department of Molecular Pharmacology & Physiology, University of South Florida, Tampa, FL, USA
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Patil MJ, Sun H, Ru F, Meeker S, Undem BJ. Targeting C-fibers for peripheral acting anti-tussive drugs. Pulm Pharmacol Ther 2019; 56:15-19. [PMID: 30872160 DOI: 10.1016/j.pupt.2019.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/01/2019] [Accepted: 03/06/2019] [Indexed: 01/09/2023]
Abstract
Activation of vagal C-fibers is likely involved in some types of pathological coughing, especially coughing that is associated with airway inflammation. This is because stimulation of vagal C-fibers leads to strong urge to cough sensations, and because C-fiber terminals can be strongly activated by mediators associated with airway inflammation. The most direct manner in which a given mediator can activate a C-fiber terminal is through interacting with its receptor expressed in the terminal membrane. The agonist-receptor interaction then must lead to the opening (or potentially closing) of ion channels that lead to a membrane depolarization. This depolarization is referred to as a generator potential. If, and only if, the generator potential reaches the voltage necessary to activate voltage-gated sodium channels, action potentials are initiated and conducted to the central terminals within the CNS. Therefore, there are three target areas to block the inflammatory mediator induced activation of C-fiber terminals. First, at the level of the mediator-receptor interaction, secondly at the level of the generator potential, and third at the level of the voltage-gated sodium channels. Here we provide a brief overview of each of these therapeutic strategies.
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Affiliation(s)
- Mayur J Patil
- Department of Medicine, Johns Hopkins University School of Medicine, USA
| | - Hui Sun
- Department of Medicine, Johns Hopkins University School of Medicine, USA
| | - Fei Ru
- Department of Medicine, Johns Hopkins University School of Medicine, USA
| | - Sonya Meeker
- Department of Medicine, Johns Hopkins University School of Medicine, USA
| | - Bradley J Undem
- Department of Medicine, Johns Hopkins University School of Medicine, USA.
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Regulation of Cough by Voltage-Gated Sodium Channels in Airway Sensory Nerves. ACTA MEDICA MARTINIANA 2019. [DOI: 10.2478/acm-2018-0012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Abstract
Chronic cough is a significant clinical problem in many patients. Current cough suppressant therapies are largely ineffective and have many dangerous adverse effects. Therefore, the identification of novel therapeutic targets and strategies for chronic cough treatment may lead to development of novel effective antitussive therapies with fewer adverse effects. The experimental research in the area of airway sensory nerves suggests that there are two main vagal afferent nerve subtypes that can directly activate cough – extrapulmonary airway C-fibres and Aδ-fibres (described as cough receptors) innervating the trachea. There are different receptors on the vagal nerve terminals that can trigger coughing, such as TRP channels and P2X2/3 receptors. However, in many patients with chronic respiratory diseases multiple activation of these receptors could be involved and it is also difficult to target these receptors. For that reason, a strategy that would inhibit cough-triggering nerve afferents regardless of activated receptors would be of great benefit. In recent years huge progress in understanding of voltage-gated sodium channels (NaVs) leads to a hypothesis that selective targeting of NaVs in airways may represent an effective treatment of pathological cough. The NaVs (NaV1.1 – NaV1.9) are essential for initiation and conduction of action potentials in these nerve fibres. Effective blocking of NaVs will prevent communication between airways and central nervous system and that would inhibit provoked cough irrespective to stimuli. This review provides an overview of airway afferent nerve subtypes that have been described in respiratory tract of human and in animal models. Moreover, the review highlights the current knowledge about cough, the sensory nerves involved in cough, and the voltage-gated sodium channels as a novel neural target in regulation of cough.
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29
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Reznikov LR, Liao YSJ, Gu T, Davis KM, Kuan SP, Atanasova KR, Dadural JS, Collins EN, Guevara MV, Vogt K. Sex-specific airway hyperreactivity and sex-specific transcriptome remodeling in neonatal piglets challenged with intra-airway acid. Am J Physiol Lung Cell Mol Physiol 2018; 316:L131-L143. [PMID: 30407862 DOI: 10.1152/ajplung.00417.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Acute airway acidification is a potent stimulus of sensory nerves and occurs commonly with gastroesophageal reflux disease, cystic fibrosis, and asthma. In infants and adults, airway acidification can acutely precipitate asthma-like symptoms, and treatment-resistant asthma can be associated with gastroesophageal reflux disease. Airway protective behaviors, such as mucus secretion and airway smooth muscle contraction, are often exaggerated in asthma. These behaviors are manifested through activation of neural circuits. In some populations, the neural response to acid might be particularly important. For example, the immune response in infants is relatively immature compared with adults. Infants also have a high frequency of gastroesophageal reflux. Thus, in the current study, we compared the transcriptomes of an airway-nervous system circuit (e.g., tracheal epithelia, nodose ganglia, and brain stem) in neonatal piglets challenged with intra-airway acid. We hypothesized that the identification of parallel changes in the transcriptomes of two neutrally connected tissues might reveal the circuit response, and, hence, molecules important for the manifestation of asthma-like features. Intra-airway acid induced airway hyperreactivity and airway obstruction in male piglets. In contrast, female piglets displayed airway obstruction without airway hyperreactivity. Pairwise comparisons revealed parallel changes in genes directly implicated in airway hyperreactivity ( scn10a) in male acid-challenged piglets, whereas acid-challenged females exhibited parallel changes in genes associated with mild asthma ( stat 1 and isg15). These findings reveal sex-specific responses to acute airway acidification and highlight distinct molecules within a neural circuit that might be critical for the manifestation of asthma-like symptoms in pediatric populations.
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Affiliation(s)
- Leah R Reznikov
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Yan Shin J Liao
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Tongjun Gu
- Bioinformatics, Interdisciplinary Center for Biotechnology Research, University of Florida , Gainesville, Florida
| | - Katelyn M Davis
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Shin Ping Kuan
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Kalina R Atanasova
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Joshua S Dadural
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Emily N Collins
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Maria V Guevara
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
| | - Kevin Vogt
- Department of Physiological Sciences, University of Florida , Gainesville, Florida
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Rai Z, Fowles H, Wright C, Howard J, Morice A. The effect of pH on citric acid cough challenge: A randomised control trial in chronic cough and healthy volunteers. Respir Physiol Neurobiol 2018. [DOI: 10.1016/j.resp.2018.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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31
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Chou YL, Mori N, Canning BJ. Opposing effects of bronchopulmonary C-fiber subtypes on cough in guinea pigs. Am J Physiol Regul Integr Comp Physiol 2017; 314:R489-R498. [PMID: 29187382 DOI: 10.1152/ajpregu.00313.2017] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We have addressed the hypothesis that the opposing effects of bronchopulmonary C-fiber activation on cough are attributable to the activation of C-fiber subtypes. Coughing was evoked in anesthetized guinea pigs by citric acid (0.001-2 M) applied topically in 100-µl aliquots to the tracheal mucosa. In control preparations, citric acid evoked 10 ± 1 coughs cumulatively. Selective activation of the pulmonary C fibers arising from the nodose ganglia with either aerosols or continuous intravenous infusion of adenosine or the 5-HT3 receptor-selective agonist 2-methyl-5-HT nearly abolished coughing evoked subsequently by topical citric acid challenge. Delivering adenosine or 2-methyl-5-HT directly to the tracheal mucosa (where few if any nodose C fibers terminate) was without effect on citric acid-evoked cough. These actions of pulmonary administration of adenosine and 2-methyl-5-HT were accompanied by an increase in respiratory rate, but it is unlikely that the change in respiratory pattern caused the decrease in coughing, as the rapidly adapting receptor stimulant histamine also produced a marked tachypnea but was without effect on cough. In awake guinea pigs, adenosine failed to evoke coughing but reduced coughing induced by the nonselective C-fiber stimulant capsaicin. We conclude that bronchopulmonary C-fiber subtypes in guinea pigs have opposing effects on cough, with airway C fibers arising from the jugular ganglia initiating and/or sensitizing the cough reflex and the intrapulmonary C fibers arising from the nodose ganglia actively inhibiting cough upon activation.
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Affiliation(s)
- Yang-Ling Chou
- Johns Hopkins Asthma and Allergy Center , Baltimore, Maryland
| | - Nanako Mori
- Johns Hopkins Asthma and Allergy Center , Baltimore, Maryland
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Šutovská M, Kočmálová M, Pappová L, Fraňová S, Chyba A, Kopecký J, Lukavský J, Cepák V, Capek P. The chemical profile and pharmacodynamic properties of extracellular Wollea saccata biopolymer. Int J Biol Macromol 2017; 103:863-869. [PMID: 28528945 DOI: 10.1016/j.ijbiomac.2017.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 01/28/2017] [Accepted: 05/03/2017] [Indexed: 11/19/2022]
Abstract
Microalgae organisms are of interest for many biotechnology applications due to the production of a wide range of biologically active compounds. Incubation of Wollea saccata in a large scale afforded a mucilaginous, high molecular weight biopolymer composed of carbohydrate, protein and phenolic compounds. Sugar moiety was rich in hexoses (60%) and 6-deoxyhexoses (31%), while only 9% of pentoses was identified. Methylation analysis revealed about 40 types of methylated sugar derivatives, suggesting a very complex structure of Wollea biopolymer. Pharmacological studies revealed new pharmacodynamic properties of cyanobacteria biopolymer, i.e. antitussive and bronchodilatory. Biopolymer was able to suppress the cough reflex induced by chemical tussigen, but its effect was lower than that of codeine, the strongest antitussive agent. The bronchodilatory effect was similar or higher than the effect of salbutamol, a bronchodilatory drug used in a clinical practice. In pharmacological studies, there were no signs of toxicity or side effects in the animals following administration of Wollea biopolymer.
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Affiliation(s)
- Martina Šutovská
- Department of Pharmacology and BioMed Martin, Jessenius Faculty of Medicine, Mala Hora 11161/4B, 036 01 Martin, Slovakia
| | - Michaela Kočmálová
- Department of Pharmacology and BioMed Martin, Jessenius Faculty of Medicine, Mala Hora 11161/4B, 036 01 Martin, Slovakia
| | - Lenka Pappová
- Department of Pharmacology and BioMed Martin, Jessenius Faculty of Medicine, Mala Hora 11161/4B, 036 01 Martin, Slovakia
| | - Soňa Fraňová
- Department of Pharmacology and BioMed Martin, Jessenius Faculty of Medicine, Mala Hora 11161/4B, 036 01 Martin, Slovakia
| | - Andrej Chyba
- Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dubravska cesta 9, 845 38 Bratislava, Slovakia
| | - Jiří Kopecký
- Institute of Botany, Academy of Sciences of the Czech Republic, Biorefinery Research Centre of Competence, Dukelská 135, 379 82 Trebon, Czech Republic
| | - Jaromír Lukavský
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Department of Autotrophic Microorganisms, 379 01 Trebon, Czech Republic
| | - Vladislav Cepák
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Department of Autotrophic Microorganisms, 379 01 Trebon, Czech Republic
| | - Peter Capek
- Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dubravska cesta 9, 845 38 Bratislava, Slovakia.
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Hsu CC, Lin YS, Lin RL, Lee LY. Immediate and delayed potentiating effects of tumor necrosis factor-α on TRPV1 sensitivity of rat vagal pulmonary sensory neurons. Am J Physiol Lung Cell Mol Physiol 2017; 313:L293-L304. [PMID: 28522561 DOI: 10.1152/ajplung.00235.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 05/05/2017] [Accepted: 05/06/2017] [Indexed: 01/19/2023] Open
Abstract
We studied acute effects of tumor necrosis factor-α (TNFα) on the sensitivity of isolated rat vagal pulmonary sensory neurons. Our results showed the following. First, a brief pretreatment with a low dose of TNFα (1.44 nM, 9 min) enhanced the sensitivity of transient receptor potential vanilloid type 1 (TRPV1) receptors in these neurons in two distinct phases: the inward current evoked by capsaicin was amplified (Δ = 247%) immediately following the TNFα pretreatment, which gradually declined toward control and then increased again reaching another peak (Δ = 384%) after 60-90 min. Second, the immediate phase of this potentiating effect of TNFα was completely abolished by a pretreatment with a selective cyclooxygenase-2 (COX-2) inhibitor, NS-398, whereas the delayed potentiation was only partially attenuated. Third, in sharp contrast, TNFα did not generate any potentiating effect on the responses to non-TRPV1 chemical activators of these neurons. Fourth, the selectivity of the TNFα action on TRPV1 was further illustrated by the responses to acid (pH 6.0); TNFα did not affect the rapid transient current mediated by acid-sensing ion channels but significantly augmented the slow sustained current mediated by TRPV1 in the same neurons. Fifth, in anesthetized rats, a similar pattern of acute sensitizing effects of TNFα on pulmonary C-fiber afferents and the involvement of COX-2 were also clearly shown. In conclusion, a brief pretreatment with TNFα induced both immediate and delayed potentiating effects on the TRPV1 sensitivity in pulmonary sensory neurons, and the production of COX-2 arachidonic acid metabolites plays a major role in the immediate sensitizing effect of TNFα.
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Affiliation(s)
- Chun-Chun Hsu
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky.,School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; and
| | - You Shuei Lin
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ruei-Lung Lin
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky;
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Bronchodilator therapy for chronic cough. Pulm Pharmacol Ther 2017; 47:88-92. [PMID: 28527922 DOI: 10.1016/j.pupt.2017.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 02/08/2023]
Abstract
Experimental studies indicate that airway calibre increases the sensitivity of the afferents involved in the cough reflex but it has proved difficult to demonstrate that airway calibre increases the sensitivity of the afferents involved in the cough reflex. Therefore, bronchodilators might have a role, although rather minor, in the treatment of cough. However, although bronchodilators represent the standard of care in the treatment of airway obstruction associated with asthma or COPD, controversy persists regarding the mechanism(s) by which these agents alleviate cough. Furthermore, the available evidence indicates that the effects of bronchodilators on cough are rather inconsistent in humans and casts doubt on the appropriateness of the common practice of using bronchodilators in the treatment of patients with cough without any other evidence of airway obstruction. Regrettably, appropriate long-term trials specifically aimed at evaluating the clinical efficacy of bronchodilators in pathologic cough have not yet been performed. Therefore, properly executed clinical studies of bronchodilators in various types of acute and chronic pathologic cough are required.
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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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Tsujimura T, Sakai S, Suzuki T, Ujihara I, Tsuji K, Magara J, Canning BJ, Inoue M. Central inhibition of initiation of swallowing by systemic administration of diazepam and baclofen in anaesthetized rats. Am J Physiol Gastrointest Liver Physiol 2017; 312:G498-G507. [PMID: 28254772 PMCID: PMC6347068 DOI: 10.1152/ajpgi.00299.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 02/15/2017] [Accepted: 02/26/2017] [Indexed: 01/31/2023]
Abstract
Dysphagia is caused not only by neurological and/or structural damage but also by medication. We hypothesized memantine, dextromethorphan, diazepam, and baclofen, all commonly used drugs with central sites of action, may regulate swallowing function. Swallows were evoked by upper airway (UA)/pharyngeal distension, punctate mechanical stimulation using a von Frey filament, capsaicin or distilled water (DW) applied topically to the vocal folds, and electrical stimulation of a superior laryngeal nerve (SLN) in anesthetized rats and were documented by recording electromyographic activation of the suprahyoid and thyrohyoid muscles and by visualizing laryngeal elevation. The effects of intraperitoneal or topical administration of each drug on swallowing function were studied. Systemic administration of diazepam and baclofen, but not memantine or dextromethorphan, inhibited swallowing evoked by mechanical, chemical, and electrical stimulation. Both benzodiazepines and GABAA receptor antagonists diminished the inhibitory effects of diazepam, whereas a GABAB receptor antagonist diminished the effects of baclofen. Topically applied diazepam or baclofen had no effect on swallowing. These data indicate that diazepam and baclofen act centrally to inhibit swallowing in anesthetized rats.NEW & NOTEWORTHY Systemic administration of diazepam and baclofen, but not memantine or dextromethorphan, inhibited swallowing evoked by mechanical, chemical, and electrical stimulation. Both benzodiazepines and GABAA receptor antagonists diminished the inhibitory effects of diazepam, whereas a GABAB receptor antagonist diminished the effects of baclofen. Topical applied diazepam or baclofen was without effect on swallowing. Diazepam and baclofen act centrally to inhibit swallowing in anesthetized rats.
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Affiliation(s)
- Takanori Tsujimura
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | - Shogo Sakai
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | - Taku Suzuki
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | - Izumi Ujihara
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | - Kojun Tsuji
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | - Jin Magara
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
| | | | - Makoto Inoue
- 1Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; and
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Reznikov LR, Meyerholz DK, Adam RJ, Abou Alaiwa M, Jaffer O, Michalski AS, Powers LS, Price MP, Stoltz DA, Welsh MJ. Acid-Sensing Ion Channel 1a Contributes to Airway Hyperreactivity in Mice. PLoS One 2016; 11:e0166089. [PMID: 27820848 PMCID: PMC5098826 DOI: 10.1371/journal.pone.0166089] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/22/2016] [Indexed: 01/10/2023] Open
Abstract
Neurons innervating the airways contribute to airway hyperreactivity (AHR), a hallmark feature of asthma. Several observations suggested that acid-sensing ion channels (ASICs), neuronal cation channels activated by protons, might contribute to AHR. For example, ASICs are found in vagal sensory neurons that innervate airways, and asthmatic airways can become acidic. Moreover, airway acidification activates ASIC currents and depolarizes neurons innervating airways. We found ASIC1a protein in vagal ganglia neurons, but not airway epithelium or smooth muscle. We induced AHR by sensitizing mice to ovalbumin and found that ASIC1a-/- mice failed to exhibit AHR despite a robust inflammatory response. Loss of ASIC1a also decreased bronchoalveolar lavage fluid levels of substance P, a sensory neuropeptide secreted from vagal sensory neurons that contributes to AHR. These findings suggest that ASIC1a is an important mediator of AHR and raise the possibility that inhibiting ASIC channels might be beneficial in asthma.
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Affiliation(s)
- Leah R. Reznikov
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - David K. Meyerholz
- Department of Pathology, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ryan J. Adam
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, Iowa, United States of America
| | - Mahmoud Abou Alaiwa
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Omar Jaffer
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Andrew S. Michalski
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Linda S. Powers
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Margaret P. Price
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - David A. Stoltz
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Molecular Physiology and Biophysics, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, Iowa, United States of America
| | - Michael J. Welsh
- Department of Internal Medicine, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Molecular Physiology and Biophysics, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Pappajohn Biomedical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Howard Hughes Medical Institute, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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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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Clay E, Patacchini R, Trevisani M, Preti D, Branà MP, Spina D, Page C. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs. J Pharmacol Exp Ther 2016; 357:73-83. [PMID: 26837703 PMCID: PMC4977573 DOI: 10.1124/jpet.115.230227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/02/2016] [Indexed: 12/12/2022] Open
Abstract
Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs.
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Affiliation(s)
- Emlyn Clay
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Riccardo Patacchini
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Marcello Trevisani
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Delia Preti
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Maria Pia Branà
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Domenico Spina
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
| | - Clive Page
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (E.C., D.S., C.P.); Department of Corporate Drug Development (R.P.), and Department of Pharmacology (M.T.), Chiesi Farmaceutici SpA, Parma, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy (D.P.); and Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy (M.P.B.)
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Taylor-Clark TE. Role of reactive oxygen species and TRP channels in the cough reflex. Cell Calcium 2016; 60:155-62. [PMID: 27016063 DOI: 10.1016/j.ceca.2016.03.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 12/15/2022]
Abstract
The cough reflex is evoked by noxious stimuli in the airways. Although this reflex is essential for health, it can be triggered chronically in inflammatory and infectious airway disease. Neuronal transient receptor potential (TRP) channels such as ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) are polymodal receptors expressed on airway nociceptive afferent nerves. Reactive oxygen species (ROS) and other reactive compounds are associated with inflammation, from either NADPH oxidase or mitochondria. These reactive compounds cause activation and hyperexcitability of nociceptive afferents innervating the airways, and evidence suggests key contributions of TRPA1 and TRPV1.
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Affiliation(s)
- Thomas E Taylor-Clark
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., Tampa, FL 33612, USA.
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Driessen AK, Farrell MJ, Mazzone SB, McGovern AE. The Role of the Paratrigeminal Nucleus in Vagal Afferent Evoked Respiratory Reflexes: A Neuroanatomical and Functional Study in Guinea Pigs. Front Physiol 2015; 6:378. [PMID: 26733874 PMCID: PMC4685097 DOI: 10.3389/fphys.2015.00378] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/23/2015] [Indexed: 02/05/2023] Open
Abstract
The respiratory tree receives sensory innervation from the jugular and nodose vagal sensory ganglia. Neurons of these ganglia are derived from embryologically distinct origins and as such demonstrate differing molecular, neurochemical and physiological phenotypes. Furthermore, whereas nodose afferent neurons project to the nucleus of the solitary tract (nTS), recent neuroanatomical studies in rats suggest that jugular neurons have their central terminations in the paratrigeminal nucleus (Pa5). In the present study we confirm that guinea pigs demonstrate a comparable distinction between the brainstem terminations of nodose and jugular ganglia afferents. Thus, microinjection of fluorescently conjugated cholera toxin B (CT-B) neural tracers into the caudal nTS and Pa5 resulted in highly specific retrograde labeling of neurons in the nodose and jugular ganglia, respectively. Whereas, nodose neurons more often expressed 160 KD neurofilament proteins and the alpha3 subunit of Na+/K+ ATPase, significantly more jugular neurons expressed the neuropeptides substance P (SP) and, especially, Calcitonin Gene-Related Peptide (CGRP). Indeed, terminal fibers in the Pa5 compared to the nTS were characterized by their significantly greater expression of CGRP, further supporting the notion that jugular afferents project to trigeminal-related brainstem regions. Electrical stimulation of the guinea pig larynx following selective surgical denervation of the nodose afferent innervation to the larynx (leaving intact the jugular innervation) resulted in stimulus dependent respiratory slowing and eventual apnea. This jugular ganglia neuron mediated response was unaffected by bilateral microinjections of the GABAA agonist muscimol into the nTS, but was abolished by muscimol injected into the Pa5. Taken together these data confirm that jugular and nodose vagal ganglia afferent neurons innervate distinct central circuits and support the notion that multiple peripheral and central pathways mediate sensory responses associated with airway irritations.
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Affiliation(s)
- Alexandria K Driessen
- School of Biomedical Sciences, The University of Queensland St Lucia, QLD, Australia
| | - Michael J Farrell
- Monash Biomedicine Discovery Institute and Department of Medical Imaging and Radiation Sciences, Monash University Clayton, VIC Australia
| | - Stuart B Mazzone
- School of Biomedical Sciences, The University of Queensland St Lucia, QLD, Australia
| | - Alice E McGovern
- School of Biomedical Sciences, The University of Queensland St Lucia, QLD, Australia
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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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Browning KN. Role of central vagal 5-HT3 receptors in gastrointestinal physiology and pathophysiology. Front Neurosci 2015; 9:413. [PMID: 26578870 PMCID: PMC4625078 DOI: 10.3389/fnins.2015.00413] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 10/15/2015] [Indexed: 12/21/2022] Open
Abstract
Vagal neurocircuits are vitally important in the co-ordination and modulation of GI reflexes and homeostatic functions. 5-hydroxytryptamine (5-HT; serotonin) is critically important in the regulation of several of these autonomic gastrointestinal (GI) functions including motility, secretion and visceral sensitivity. While several 5-HT receptors are involved in these physiological responses, the ligand-gated 5-HT3 receptor appears intimately involved in gut-brain signaling, particularly via the afferent (sensory) vagus nerve. 5-HT is released from enterochromaffin cells in response to mechanical or chemical stimulation of the GI tract which leads to activation of 5-HT3 receptors on the terminals of vagal afferents. 5-HT3 receptors are also present on the soma of vagal afferent neurons, including GI vagal afferent neurons, where they can be activated by circulating 5-HT. The central terminals of vagal afferents also exhibit 5-HT3 receptors that function to increase glutamatergic synaptic transmission to second order neurons of the nucleus tractus solitarius within the brainstem. While activation of central brainstem 5-HT3 receptors modulates visceral functions, it is still unclear whether central vagal neurons, i.e., nucleus of the tractus solitarius (NTS) and dorsal motor nucleus of the vagus (DMV) neurons themselves also display functional 5-HT3 receptors. Thus, activation of 5-HT3 receptors may modulate the excitability and activity of gastrointestinal vagal afferents at multiple sites and may be involved in several physiological and pathophysiological conditions, including distention- and chemical-evoked vagal reflexes, nausea, and vomiting, as well as visceral hypersensitivity.
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Affiliation(s)
- Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine Hershey, PA, USA
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Ru F, jr BP, Kollarik M. Acid sensitivity of the spinal dorsal root ganglia C-fiber nociceptors innervating the guinea pig esophagus. Neurogastroenterol Motil 2015; 27:865-74. [PMID: 25846134 PMCID: PMC4446164 DOI: 10.1111/nmo.12561] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 03/05/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Gastroesophageal reflux can cause high acidity in the esophagus and trigger heartburn and pain. However, because of the esophageal mucosal barrier, the acidity at the nerve terminals of pain-mediating C-fibers in esophageal mucosa is predicted to be substantially lower. We hypothesized that the esophageal dorsal root ganglia (DRG) C-fibers are activated by mild acid (compared to acidic reflux), and express receptors and ion channels highly sensitive to acid. METHODS Extracellular single unit recordings of activity originating in esophageal DRG C-fiber nerve terminals were performed in the innervated esophagus preparation ex vivo. Acid was delivered in a manner that bypassed the esophageal mucosal barrier. The expression of mRNA for selected receptors in esophagus-specific DRG neurons was evaluated using single cell RT-PCR. KEY RESULTS Mild acid (pH = 6.5-5.5) activated esophageal DRG C-fibers in a pH-dependent manner. The response to mild acid at pH = 6 was not affected by the TRPV1 selective antagonist iodo-resiniferatoxin. The majority (70-95%) of esophageal DRG C-fiber neurons (TRPV1-positive) expressed mRNA for acid sensing ion channels (ASIC1a, ASIC1b, ASIC2b, and/or ASIC3), two-pore-domain (K2P) potassium channel TASK1, and the proton-sensing G-protein coupled receptor OGR1. Other evaluated targets (PKD2L1, TRPV4, TASK3, TALK1, G2A, GPR4, and TDAG8) were expressed rarely. CONCLUSIONS & INFERENCES Guinea pig esophageal DRG C-fibers are activated by mild acid via a TRPV1-independent mechanism, and express mRNA for several receptors and ion channels highly sensitive to acid. The high acid sensitivity of esophageal C-fibers may contribute to heartburn and pain in conditions of reduced mucosal barrier function.
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Affiliation(s)
- F Ru
- Medicine, The Johns Hopkins University School of Medicine, Baltimore, USA
| | - Banovcin P jr
- Pathophysiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia,Gastroenterology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - M Kollarik
- Medicine, The Johns Hopkins University School of Medicine, Baltimore, USA
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Poussel M, Thil C, Kaminsky P, Mercy M, Gomez E, Chaouat A, Chabot F, Chenuel B. Lack of correlation between the ventilatory response to CO2 and lung function impairment in myotonic dystrophy patients: Evidence for a dysregulation at central level. Neuromuscul Disord 2015; 25:403-8. [DOI: 10.1016/j.nmd.2015.02.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 02/04/2015] [Accepted: 02/11/2015] [Indexed: 11/27/2022]
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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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McGovern AE, Mazzone SB. Guinea pig models of asthma. CURRENT PROTOCOLS IN PHARMACOLOGY 2014; 67:5.26.1-5.26.38. [PMID: 25446291 DOI: 10.1002/0471141755.ph0526s67] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Described in this unit are methods for establishing guinea pig models of asthma. Sufficient detail is provided to enable investigators to study bronchoconstriction, cough, airway hyperresponsiveness, inflammation, and remodeling.
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Affiliation(s)
- Alice E McGovern
- School of Biomedical Sciences, University of Queensland, St Lucia, Australia
| | - Stuart B Mazzone
- School of Biomedical Sciences, University of Queensland, St Lucia, Australia
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