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Zhou L, Hao M, Fan X, Lao Z, Li M, Shang E. Effects of Houpo Mahuang Decoction on serum metabolism and TRPV1/Ca 2+/TJs in asthma. JOURNAL OF ETHNOPHARMACOLOGY 2023; 302:115873. [PMID: 36309114 DOI: 10.1016/j.jep.2022.115873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/06/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Houpo Mahuang Decoction (HPMHD is one of the classic traditional Chinese prescriptions that has been used in the treatment of asthma. The therapeutic effects and mechanism of HPMHD in aggravated asthma remain to be explored, especially from the perspective of metabolomics and Transient Receptor Potential Vanilloid-1 (TRPV1)/Ca2+/Tight junction (TJ) regulation. AIM OF THE STUDY To investigate the therapeutic and metabolic regulatory effects and the underlying mechanism of HPMHD in asthmatic rats. MATERIALS AND METHODS The asthmatic rats were administered with the corresponding HPMHD (at dosages of 5.54, 11.07, 22.14 mg/kg). Then inflammatory cells in peripheral blood and bronchoalveolar lavage fluid (BALF) were counted, the levels of interleukin (IL)-4 and IL-13 in BALF were measured, and the changes in enhanced pause (Penh) and pathological damage of lung tissues were also detected to evaluate the protective effects of HPMHD. The serum metabolic profile of HPMHD in asthmatic rats was explored using Ultra-High-Performance Liquid Chromatography-mass spectrometer (UHPLC-MS), and the regulatory effects on TRPV1 and TJs of HPMHD in asthmatic rats were detected by Western blotting analysis. In vitro, 16HBE cells were stimulated with IL-4 plus SO2 derivatives and then administered HPMHD. The intracellular Ca2+ regulated by TRPV1, and the expression levels of TRPV1 and TJ proteins (TJs) were then detected by calcium imaging and Western blotting. The effects were verified by inhibition of TRPV1 and in short hairpin RNA (shRNA)-mediated TRPV1 silencing cells. RESULTS HPMHD significantly attenuated the airway inflammation of asthmatic rats, and reduced the levels of inflammatory cells in peripheral blood and BALF as well as the levels of IL-4 plus IL-13 in BALF. In addition, the airway hyperresponsiveness and lung pathological damage were alleviated. Serum metabolomic analysis showed that 31 metabolites were differentially expressed among the normal saline-, model-, and HPMHD-treated rats. Pathway enrichment analysis showed that the metabolites were involved in 45 pathways, among which, TJs regulation-relevant pathway was associated with the Ca2+ concentration change mediated by the TRP Vanilloid channel. In vivo and in vitro experiments indicated that HPMHD reduced the concentration of intracellular Ca2+ via suppressing the expression and activation of TRPV1, increased the expression of ZO-1, Occludin, and Claudin-3, and protected the integrity of TJs. CONCLUSION The current study indicates that HPMHD alleviates rat asthma and participates in the regulation of serum metabolism. The anti-asthma effects of HPMHD might be related to the protection of TJs by inhibiting the intracellular Ca2+ concentration via TRPV1.
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Affiliation(s)
- Liping Zhou
- School of Traditional Chinese Medicine & Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu Province, China
| | - Mengyang Hao
- School of Traditional Chinese Medicine & Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu Province, China
| | - Xinsheng Fan
- School of Traditional Chinese Medicine & Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu Province, China; Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing, 210023, Jiangsu Province, China.
| | - Zishan Lao
- School of Traditional Chinese Medicine & Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu Province, China
| | - Mengwen Li
- School of Traditional Chinese Medicine & Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu Province, China
| | - Erxin Shang
- Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing, 210023, Jiangsu Province, China
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Xiao T, Sun M, Kang J, Zhao C. Transient Receptor Potential Vanilloid1 (TRPV1) Channel Opens Sesame of T Cell Responses and T Cell-Mediated Inflammatory Diseases. Front Immunol 2022; 13:870952. [PMID: 35634308 PMCID: PMC9130463 DOI: 10.3389/fimmu.2022.870952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential vanilloid1 (TRPV1) was primarily expressed in sensory neurons, and could be activated by various physical and chemical factors, resulting in the flow of extracellular Ca2+ into cells. Accumulating data suggest that the TRPV1 is expressed in some immune cells and is a novel regulator of the immune system. In this review, we highlight the structure and biological features of TRPV1 channel. We also summarize recent findings on its role in modulating T cell activation and differentiation as well as its protective effect in T cell-mediated inflammatory diseases and potential mechanisms.
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Affiliation(s)
- Tengfei Xiao
- Department of Clinical Laboratory, The Sixth Affiliated Hospital of Nantong University, Yancheng Third People’s Hospital, Yancheng, China
| | - Mingzhong Sun
- Department of Clinical Laboratory, The Sixth Affiliated Hospital of Nantong University, Yancheng Third People’s Hospital, Yancheng, China
| | - Jingjing Kang
- Department of Clinical Laboratory, Affiliated Hospital of Nanjing University Medical School, Yancheng First People’s Hospital, Yancheng, China
| | - Chuanxiang Zhao
- Institute of Medical Genetics and Reproductive Immunity, School of Medical Science and Laboratory Medicine, Jiangsu College of Nursing, Huai’an, China
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Xu J, Ghadiri M, Svolos M, McParland B, Traini D, Ong HX, Young PM. Investigating Potential TRPV1 Positive Feedback to Explain TRPV1 Upregulation in Airway Disease States. Drug Dev Ind Pharm 2022; 47:1924-1934. [PMID: 35473456 DOI: 10.1080/03639045.2022.2070759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE The airway epithelium is a potential source of pathophysiology through activation of transient potential receptor vallinoid type 1 (TRPV1) channel. A positive feedback cycle caused by TRPV1 activity is hypothesised to induce upregulation and production of inflammatory cytokines, leading to exacerbations of chronic airway diseases. These cytokine and protein regulation effects were investigated in this study. METHODS Healthy (BEAS-2B) and cancer-derived (Calu-3) airway epithelial cell lines were assessed for changes to TRPV1 protein expression and mRNA expression following exposure to capsaicin (5 µM to 50 µM), and TRPV1 modulators including heat (43 °C), and hydrochloric acid (pH 3.4 to pH 6.4). Cytotoxicity was measured to determine the working concentration ranges of treatment. Subsequent bronchoconstriction by TRPV1 activation with capsaicin was measured on guinea pig airway tissue to confirm locally mediated activity without the action of known neuronal inputs. RESULTS TRPV1 protein expression was not different for all capsaicin, acidity, and heat exposures (P > 0.05), and was replicated in mRNA protein expression (P > 0.05). IL-6 and IL-8 expression were lower in BEAS-2B and Calu-3 cell lines exposed with acidity and heat (P < 0.05), but not consistently with capsaicin exposure, with potential cytotoxic effects possible. CONCLUSIONS TRPV1 expression was present in airway epithelial cells but its expression was not changed after activation by TRPV1 activators. Thus, it was not apparent the reason for reported TRPV1 upregulation in patients with airway disease states. More complex mechanisms are likely involved and will require further investigation.
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Affiliation(s)
- Jesse Xu
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia.,School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown NSW 2006, Australia
| | - Maliheh Ghadiri
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia
| | - Maree Svolos
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia
| | - Brent McParland
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown NSW 2006, Australia
| | - Daniela Traini
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia.,Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Australia
| | - Hui Xin Ong
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia.,Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Australia
| | - Paul M Young
- Respiratory Technology Group, Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe NSW 2037, Australia.,Department of Marketing, Macquarie Business School, Macquarie University, NSW 2109, Australia
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Harford TJ, Grove L, Rezaee F, Scheraga R, Olman MA, Piedimonte G. RSV infection potentiates TRPV 1-mediated calcium transport in bronchial epithelium of asthmatic children. Am J Physiol Lung Cell Mol Physiol 2021; 320:L1074-L1084. [PMID: 33787326 DOI: 10.1152/ajplung.00531.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The transient receptor potential vanilloid 1 (TRPV1) channel is expressed in human bronchial epithelium (HBE), where it transduces Ca2+ in response to airborne irritants. TRPV1 activation results in bronchoconstriction, cough, and mucus production, and may therefore contribute to the pathophysiology of obstructive airway disease. Since children with asthma face the greatest risk of developing virus-induced airway obstruction, we hypothesized that changes in TRPV1 expression, localization, and function in the airway epithelium may play a role in bronchiolitis and asthma in childhood. We sought to measure TRPV1 protein expression, localization, and function in HBE cells from children with versus without asthma, both at baseline and after RSV infection. We determined changes in TRPV1 protein expression, subcellular localization, and function both at baseline and after RSV infection in primary HBE cells from normal children and children with asthma. Basal TRPV1 protein expression was higher in HBE from children with versus without asthma and primarily localized to plasma membranes (PMs). During RSV infection, TRPV1 protein increased more in the PM of asthmatic HBE as compared with nonasthmatic cells. TRPV1-mediated increase in intracellular Ca2+ was greater in RSV-infected asthmatic cells, but this increase was attenuated when extracellular Ca2+ was removed. Nerve growth factor (NGF) recapitulated the effect of RSV on TRPV1 activation in HBE cells. Our data suggest that children with asthma have intrinsically hyperreactive airways due in part to higher TRPV1-mediated Ca2+ influx across epithelial membranes, and this abnormality is further exacerbated by NGF overexpression during RSV infection driving additional Ca2+ from intracellular stores.
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Affiliation(s)
- Terri J Harford
- Department of Inflammation and Immunity, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Lisa Grove
- Department of Inflammation and Immunity, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Fariba Rezaee
- Department of Inflammation and Immunity, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Rachel Scheraga
- Department of Inflammation and Immunity, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Mitchell A Olman
- Department of Inflammation and Immunity, Lerner Research Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Giovanni Piedimonte
- Department of Pediatrics, Tulane School of Medicine, New Orleans, Louisiana.,Department Biochemistry & Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana
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Elias-Kirma S, Artzy-Schnirman A, Das P, Heller-Algazi M, Korin N, Sznitman J. In situ-Like Aerosol Inhalation Exposure for Cytotoxicity Assessment Using Airway-on-Chips Platforms. Front Bioeng Biotechnol 2020; 8:91. [PMID: 32154228 PMCID: PMC7044134 DOI: 10.3389/fbioe.2020.00091] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/31/2020] [Indexed: 12/02/2022] Open
Abstract
Lung exposure to inhaled particulate matter (PM) is known to injure the airway epithelium via inflammation, a phenomenon linked to increased levels of global morbidity and mortality. To evaluate physiological outcomes following PM exposure and concurrently circumvent the use of animal experiments, in vitro approaches have typically relied on traditional assays with plates or well inserts. Yet, these manifest drawbacks including the inability to capture physiological inhalation conditions and aerosol deposition characteristics relative to in vivo human conditions. Here, we present a novel airway-on-chip exposure platform that emulates the epithelium of human bronchial airways with critical cellular barrier functions at an air-liquid interface (ALI). As a proof-of-concept for in vitro lung cytotoxicity testing, we recapitulate a well-characterized cell apoptosis pathway, induced through exposure to 2 μm airborne particles coated with αVR1 antibody that leads to significant loss in cell viability across the recapitulated airway epithelium. Notably, our in vitro inhalation assays enable simultaneous aerosol exposure across multiple airway chips integrated within a larger bronchial airway tree model, under physiological respiratory airflow conditions. Our findings underscore in situ-like aerosol deposition outcomes where patterns depend on respiratory flows across the airway tree geometry and gravitational orientation, as corroborated by concurrent numerical simulations. Our airway-on-chips not only highlight the prospect of realistic in vitro exposure assays in recapitulating characteristic local in vivo deposition outcomes, such platforms open opportunities toward advanced in vitro exposure assays for preclinical cytotoxicity and drug screening applications.
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Affiliation(s)
| | | | | | | | | | - Josué Sznitman
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
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6
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Dietrich A, Steinritz D, Gudermann T. Transient receptor potential (TRP) channels as molecular targets in lung toxicology and associated diseases. Cell Calcium 2017; 67:123-137. [PMID: 28499580 DOI: 10.1016/j.ceca.2017.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 12/24/2022]
Abstract
The lungs as the gateways of our body to the external environment are essential for gas exchange. They are also exposed to toxicants from two sides, the airways and the vasculature. Apart from naturally produced toxic agents, millions of human made chemicals were produced since the beginning of the industrial revolution whose toxicity still needs to be determined. While the knowledge about toxic substances is increasing only slowly, a paradigm shift regarding the proposed mechanisms of toxicity at the plasma membrane emerged. According to their broad-range chemical reactivity, the mechanism of lung injury evoked by these agents has long been described as rather unspecific. Consequently, therapeutic options are still restricted to symptomatic treatment. The identification of molecular down-stream effectors in cells was a major step forward in the mechanistic understanding of the action of toxic chemicals and will pave the way for more causal and specific toxicity testing as well as therapeutic options. In this context, the involvement of Transient Receptor Potential (TRP) channels as chemosensors involved in the detection and effectors of toxicant action is an attractive concept intensively discussed in the scientific community. In this review we will summarize recent evidence for an involvement of TRP channels (TRPA1, TRPC4, TRPC6, TRPV1, TRPV4, TRPM2 and TRPM8) expressed in the lung in pathways of toxin sensing and as mediators of lung inflammation and associated diseases like asthma, COPD, lung fibrosis and edema formation. Specific modulators of these channels may offer new therapeutic options in the future and will endorse strategies for a causal, specifically tailored treatment based on the mechanistic understanding of molecular events induced by lung-toxic agents.
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Affiliation(s)
- Alexander Dietrich
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany.
| | - Dirk Steinritz
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany; Bundeswehr-Institute of Pharmacology and Toxicology, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany
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7
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Dubes V, Parpaite T, Ducret T, Quignard JF, Mornet S, Reinhardt N, Baudrimont I, Dubois M, Freund-Michel V, Marthan R, Muller B, Savineau JP, Courtois A. Calcium signalling induced by in vitro exposure to silicium dioxide nanoparticles in rat pulmonary artery smooth muscle cells. Toxicology 2016; 375:37-47. [PMID: 27939335 DOI: 10.1016/j.tox.2016.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/06/2016] [Accepted: 12/06/2016] [Indexed: 11/18/2022]
Abstract
The development and use of nanomaterials, especially engineered nanoparticles (NP), is expected to provide many benefits. But at the same time the development of such materials is also feared because of their potential human health risks. Indeed, NP display some characteristics similar to ultrafine environmental particles which are known to exert deleterious cardiovascular effects including pro-hypertensive ones. In this context, the effect of NP on calcium signalling, whose deregulation is often involved in hypertensive diseases, remain poorly described. We thus assessed the effect of SiO2 NP on calcium signalling by fluorescence imaging and on the proliferation response in rat pulmonary artery smooth muscle cells (PASMC). In PASMC, acute exposure to SiO2 NP, from 1 to 500μg/mL, produced an increase of the [Ca2+]i. In addition, when PASMC were exposed to NP at 200μg/mL, a proliferative response was observed. This calcium increase was even greater in PASMC isolated from rats suffering from pulmonary hypertension. The absence of extracellular calcium, addition of diltiazem or nicardipine (L-type voltage-operated calcium channel inhibitors both used at 10μM), and addition of capsazepine or HC067047 (TRPV1 and TRPV4 inhibitors used at 10μM and 5μM, respectively) significantly reduced this response. Moreover, this response was also inhibited by thapsigargin (SERCA inhibitor, 1μM), ryanodine (100μM) and dantrolene (ryanodine receptor antagonists, 10μM) but not by xestospongin C (IP3 receptor antagonist, 10μM). Thus, NP induce an intracellular calcium rise in rat PASMC originating from both extracellular and intracellular calcium sources. This study also provides evidence for the implication of TRPV channels in NP induced calcium rise that may highlight the role of these channels in the deleterious cardiovascular effects of NP.
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Affiliation(s)
- Virginie Dubes
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Thibaud Parpaite
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Thomas Ducret
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Jean-François Quignard
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Stéphane Mornet
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; CNRS, ICMCB, UPR 9048, 87 Avenue du Dr Albert Schweitzer, 33600 Pessac, France.
| | - Nora Reinhardt
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; CNRS, ICMCB, UPR 9048, 87 Avenue du Dr Albert Schweitzer, 33600 Pessac, France.
| | - Isabelle Baudrimont
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Mathilde Dubois
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Véronique Freund-Michel
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Roger Marthan
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Centre Hospitalier Universitaire de Bordeaux, Hôpital du Haut-Lévêque, Service d'Exploration Fonctionnelle Respiratoire, Avenue de Magellan, Pessac, F-33076, France.
| | - Bernard Muller
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Jean-Pierre Savineau
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France.
| | - Arnaud Courtois
- Université de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux, F-33076, France; Centre Hospitalier Universitaire de Bordeaux, Centre AntiPoison et de Toxicovigilance d'Aquitaine et de Poitou Charente, Place Amélie Raba Léon, Bordeaux, F-33076, France.
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8
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Akopian AN, Fanick ER, Brooks EG. TRP channels and traffic-related environmental pollution-induced pulmonary disease. Semin Immunopathol 2016; 38:331-8. [PMID: 26837756 PMCID: PMC4896490 DOI: 10.1007/s00281-016-0554-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/19/2016] [Indexed: 12/21/2022]
Abstract
Environmental pollutant exposures are major risk factors for adverse health outcomes, with increased morbidity and mortality in humans. Diesel exhaust (DE) is one of the major harmful components of traffic-related air pollution. Exposure to DE affects several physiological systems, including the airways, and pulmonary diseases are increased in highly populated urban areas. Hence, there are urgent needs to (1) create newer and lesser polluting fuels, (2) improve exhaust aftertreatments and reduce emissions, and (3) understand mechanisms of actions for toxic effects of both conventional and cleaner diesel fuels on the lungs. These steps could aid the development of diagnostics and interventions to prevent the negative impact of traffic-related air pollution on the pulmonary system. Exhaust from conventional, and to a lesser extent, clean fuels, contains particulate matter (PM) and more than 400 additional chemical constituents. The major toxic constituents are nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons (PAHs). PM and PAHs could potentially act via transient receptor potential (TRP) channels. In this review, we will first discuss the associations between DE from conventional as well as clean fuel technologies and acute and chronic airway inflammation. We will then review possible activation and/or potentiation of TRP vanilloid type 1 (TRPV1) and ankyrin 1 (TRPA1) channels by PM and PAHs. Finally, we will discuss and summarize recent findings on the mechanisms whereby TRPs could control the link between DE and airway inflammation, which is a primary determinant leading to pulmonary disease.
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Affiliation(s)
- Armen N Akopian
- Department of Endodontics, School of Dentistry, UT Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - E Robert Fanick
- Office of Automotive Engineering, Southwest Research Institute, San Antonio, TX, 78228, USA
| | - Edward G Brooks
- Department of Pediatrics, Division of Immunology and Infectious Disease, School of Medicine, UT Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
- Center for Airway Inflammation Research, UT Health Science Center at San Antonio, 8403 Floyd Curl Drive, STRF Microbiology MC 8259, San Antonio, TX, 78229, USA.
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9
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Hooper JS, Hadley SH, Morris KF, Breslin JW, Dean JB, Taylor-Clark TE. Characterization of cardiovascular reflexes evoked by airway stimulation with allylisothiocyanate, capsaicin, and ATP in Sprague-Dawley rats. J Appl Physiol (1985) 2015; 120:580-91. [PMID: 26718787 DOI: 10.1152/japplphysiol.00944.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 12/25/2015] [Indexed: 12/17/2022] Open
Abstract
Acute inhalation of airborne pollutants alters cardiovascular function and evidence suggests that pollutant-induced activation of airway sensory nerves via the gating of ion channels is critical to these systemic responses. Here, we have investigated the effect of capsaicin [transient receptor potential (TRP) vanilloid 1 (TRPV1) agonist], AITC [TRP ankyrin 1 (TRPA1) agonist], and ATP (P2X2/3 agonist) on bronchopulmonary sensory activity and cardiovascular responses of conscious Sprague-Dawley (SD) rats. Single fiber recordings show that allyl isothiocyanate (AITC) and capsaicin selectively activate C fibers, whereas subpopulations of both A and C fibers are activated by stimulation of P2X2/3 receptors. Inhalation of the agonists by conscious rats caused significant bradycardia, atrioventricular (AV) block, and prolonged PR intervals, although ATP-induced responses were lesser than those evoked by AITC or capsaicin. Responses to AITC were inhibited by the TRP channel blocker ruthenium red and the muscarinic antagonist atropine. AITC inhalation also caused a biphasic blood pressure response: a brief hypertensive phase followed by a hypotensive phase. Atropine accentuated the hypertensive phase, while preventing the hypotension. AITC-evoked bradycardia was not abolished by terazosin, the α1-adrenoceptor inhibitor, which prevented the hypertensive response. Anesthetics had profound effects on AITC-evoked bradycardia and AV block, which was abolished by urethane, ketamine, and isoflurane. Nevertheless, AITC inhalation caused bradycardia and AV block in paralyzed and ventilated rats following precollicular decerebration. In conclusion, we provide evidence that activation of ion channels expressed on nociceptive airway sensory nerves causes significant cardiovascular effects in conscious SD rats via reflex modulation of the autonomic nervous system.
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Affiliation(s)
- J S Hooper
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - S H Hadley
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - K F Morris
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - J W Breslin
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - J B Dean
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - T E Taylor-Clark
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
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10
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"TRP inflammation" relationship in cardiovascular system. Semin Immunopathol 2015; 38:339-56. [PMID: 26482920 PMCID: PMC4851701 DOI: 10.1007/s00281-015-0536-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 10/08/2015] [Indexed: 02/07/2023]
Abstract
Despite considerable advances in the research and treatment, the precise relationship between inflammation and cardiovascular (CV) disease remains incompletely understood. Therefore, understanding the immunoinflammatory processes underlying the initiation, progression, and exacerbation of many cardiovascular diseases is of prime importance. The innate immune system has an ancient origin and is well conserved across species. Its activation occurs in response to pathogens or tissue injury. Recent studies suggest that altered ionic balance, and production of noxious gaseous mediators link to immune and inflammatory responses with altered ion channel expression and function. Among plausible candidates for this are transient receptor potential (TRP) channels that function as polymodal sensors and scaffolding proteins involved in many physiological and pathological processes. In this review, we will first focus on the relevance of TRP channel to both exogenous and endogenous factors related to innate immune response and transcription factors related to sustained inflammatory status. The emerging role of inflammasome to regulate innate immunity and its possible connection to TRP channels will also be discussed. Secondly, we will discuss about the linkage of TRP channels to inflammatory CV diseases, from a viewpoint of inflammation in a general sense which is not restricted to the innate immunity. These knowledge may serve to provide new insights into the pathogenesis of various inflammatory CV diseases and their novel therapeutic strategies.
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11
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Jia X, Zhang H, Cao X, Yin Y, Zhang B. Activation of TRPV1 mediates thymic stromal lymphopoietin release via the Ca2+/NFAT pathway in airway epithelial cells. FEBS Lett 2014; 588:3047-54. [PMID: 24931369 DOI: 10.1016/j.febslet.2014.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/08/2014] [Accepted: 06/04/2014] [Indexed: 12/22/2022]
Abstract
The airway epithelium is exposed to a range of irritants in the environment that are known to trigger inflammatory response such as asthma. Transient receptor potential vanilloid 1 (TRPV1) is a Ca(2+)-permeable cation channel critical for detecting noxious stimuli by sensory neurons. Recently increasing evidence suggests TRPV1 is also crucially involved in the pathophysiology of asthma on airway epithelium in human. Here we report that in airway epithelial cells TRPV1 activation potently induces allergic cytokine thymic stromal lymphopoietin (TSLP) release. TSLP induction by protease-activated receptor (PAR)-2 activation is also partially mediated by TRPV1 channels.
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Affiliation(s)
- Xinying Jia
- Department of Pathology, Peking University Health Science Center, 100191 Beijing, China
| | - Hong Zhang
- Department of Pathology, Peking University Health Science Center, 100191 Beijing, China
| | - Xu Cao
- Department of Neurology, Peking University Health Science Center, 100191 Beijing, China.
| | - Yuxin Yin
- Department of Pathology, Peking University Health Science Center, 100191 Beijing, China
| | - Bo Zhang
- Department of Pathology, Peking University Health Science Center, 100191 Beijing, China.
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12
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McGarvey LP, Butler CA, Stokesberry S, Polley L, McQuaid S, Abdullah H, Ashraf S, McGahon MK, Curtis TM, Arron J, Choy D, Warke TJ, Bradding P, Ennis M, Zholos A, Costello RW, Heaney LG. Increased expression of bronchial epithelial transient receptor potential vanilloid 1 channels in patients with severe asthma. J Allergy Clin Immunol 2014; 133:704-12.e4. [DOI: 10.1016/j.jaci.2013.09.016] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 08/18/2013] [Accepted: 09/17/2013] [Indexed: 12/18/2022]
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13
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Noël J, Salinas M, Baron A, Diochot S, Deval E, Lingueglia E. Current perspectives on acid-sensing ion channels: new advances and therapeutic implications. Expert Rev Clin Pharmacol 2014; 3:331-46. [DOI: 10.1586/ecp.10.13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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14
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The degradation of airway tight junction protein under acidic conditions is probably mediated by transient receptor potential vanilloid 1 receptor. Biosci Rep 2013; 33:BSR20130087. [PMID: 24073800 PMCID: PMC3814059 DOI: 10.1042/bsr20130087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Acidic airway microenvironment is one of the representative pathophysiological features of chronic inflammatory respiratory diseases. Epithelial barrier function is maintained by TJs (tight junctions), which act as the first physical barrier against the inhaled substances and pathogens of airway. As previous studies described, acid stress caused impaired epithelial barriers and led the hyperpermeability of epithelium. However, the specific mechanism is still unclear. We have showed previously the existence of TRPV (transient receptor potential vanilloid) 1 channel in airway epithelium, as well as its activation by acidic stress in 16HBE cells. In this study, we explored the acidic stress on airway barrier function and TJ proteins in vitro with 16HBE cell lines. Airway epithelial barrier function was determined by measuring by TER (trans-epithelial electrical resistance). TJ-related protein [claudin-1, claudin-3, claudin-4, claudin-5, claudin-7 and ZO-1 (zonula occluden 1)] expression was examined by western blotting of insoluble fractions of cell extraction. The localization of TJ proteins were visualized by immunofluorescent staining. Interestingly, stimulation by pH 6.0 for 8 h slightly increased the epithelial resistance in 16HBE cells insignificantly. However, higher concentration of hydrochloric acid (lower than pH 5.0) did reduce the airway epithelial TER of 16HBE cells. The decline of epithelial barrier function induced by acidic stress exhibited a TRPV1-[Ca2+]i-dependent pathway. Of the TJ proteins, claudin-3 and claudin-4 seemed to be sensitive to acidic stress. The degradation of claudin-3 and claudin-4 induced by acidic stress could be attenuated by the specific TRPV1 blocker or intracellular Ca2+ chelator BAPTA/AM [1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester)].
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Rodríguez-Cotto RI, Ortiz-Martínez MG, Rivera- Ramírez E, Méndez LB, Dávila JC, Jiménez-Vélez BD. African Dust Storms Reaching Puerto Rican Coast Stimulate the Secretion of IL-6 and IL-8 and Cause Cytotoxicity to Human Bronchial Epithelial Cells (BEAS-2B). Health (London) 2013; 5:14-28. [PMID: 25002916 PMCID: PMC4082624 DOI: 10.4236/health.2013.510a2003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
African dust storm events (ADE) travel across the Atlantic Ocean (ADEAO) and reach the Puerto Rican coast (ADEPRC), potentially impacting air quality and human health. To what extent seasonal variations in atmospheric particulate matter (PM) size fractions, composition and sources trigger respiratory-adverse effects to Puerto Ricans is still unclear. In the present study, we investigated the pro-inflammatory and cytotoxic effects of PM samples harvested during ADEAO (PM10), ADEPRC (PM2.5 and PM10) and Non-ADE (Preand Post-ADEAO and Non-ADEPRC), using BEAS-2B cells. Endotoxins (ENX) in PM2.5 and PM10 extracts and traces of metals (TMET) in PM2.5 extracts were also examined. IL-6 and IL-8 secretion and cytotoxicity were used as endpoints. ADEAO and ADEPRC extracts were found to be more cytotoxic than Non-ADE and ADEAO were more toxic than ADEPRC extracts. PM10 extracts from ADEAO and Post-ADEAO caused significant secretion of IL-8. IL-6 and IL-8 secretion was higher following treatment with PM10 and PM2.5 ADEPRC than with Non-ADEPRC extracts. ENX levels were found to be higher in PM10 ADEAO than in the rest of the samples tested. TMET levels were higher in PM2.5 ADEPRC than in Non-ADEPRC extracts. Deferoxamine significantly reduced cytotoxicity and IL-6 and IL-8 secretion whereas Polymyxin B did not. TMET in PM2.5 fractions is a major determinant in ADEPRC-induced toxicity and work in conjunction with ENX to cause toxicity to lung cells in vitro. ENX and TMET may be responsible, in part, for triggering PM-respiratory adverse responses in susceptible and predisposed individuals.
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Affiliation(s)
- Rosa I. Rodríguez-Cotto
- Department of Biochemistry, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
| | - Mario G. Ortiz-Martínez
- Department of Biochemistry, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
| | - Evasomary Rivera- Ramírez
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
- Department of Biology, University of Puerto Rico-Río Piedras Campus, San Juan, Puerto Rico
| | - Loyda B. Méndez
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
- Science and Technology School, Eastern University, Carolina, Puerto Rico
| | - Julio C. Dávila
- Department of Biochemistry, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
| | - Braulio D. Jiménez-Vélez
- Department of Biochemistry, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
- Center for Environmental and Toxicological Research, San Juan, Puerto Rico
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Yu H, Li Q, Kolosov VP, Perelman JM, Zhou X. Regulation of particulate matter-induced mucin secretion by transient receptor potential vanilloid 1 receptors. Inflammation 2013; 35:1851-9. [PMID: 22829138 DOI: 10.1007/s10753-012-9506-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Exposure to airborne particulate matter (PM) is a worldwide health problem. Previous studies have reported that PMs induced depolarizing currents and increased intracellular Ca(2+) in human bronchial epithelial cells. Ca(2+) plays important role in the regulation of mucus exocytosis, and mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. To explore more mechanisms underlying PM toxicity, we measured PM-induced mucin secretion in human bronchial epithelial (16HBE) cells. MUC5AC secretion and cyclic adenosine monophosphate (cAMP) level were detected by ELISA. Transient receptor potential vanilloid (TRPV)1 inward currents were examined by electrophysiology. Ca(2+) concentration was assessed by laser scanning confocal microscope. Exposure of PMs to 16HBE cells was found to induce mucin secretion, as a consequence of sustained Ca(2+) influx and cAMP increase through TRPV1 receptors. Mucin secretion was completely inhibited by TRPV1 receptor antagonist capsazepine. Removal of Ca(2+) by Ca(2+) chelator BAPTA or inhibition of protein kinase A (PKA) by the PKA inhibitors H-89 each partially reduced PC(2)s-induced mucin secretion. The combination of BAPTA and H-89 completely prevented mucin secretion mediated by PMs. These results suggest that PM induces mucin secretion through Ca(2+) influx and cAMP/PKA pathway by TRPV1 receptors in human bronchial epithelial cells, thereby providing a potential mechanism to reduce PM toxicity.
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Affiliation(s)
- Hongmei Yu
- Division of Respiratory Medicine, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
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Fariss MW, Gilmour MI, Reilly CA, Liedtke W, Ghio AJ. Emerging mechanistic targets in lung injury induced by combustion-generated particles. Toxicol Sci 2013; 132:253-67. [PMID: 23322347 PMCID: PMC4447844 DOI: 10.1093/toxsci/kft001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/21/2012] [Indexed: 12/25/2022] Open
Abstract
The mechanism for biological effect following exposure to combustion-generated particles is incompletely defined. The identification of pathways regulating the acute toxicological effects of these particles provides specific targets for therapeutic manipulation in an attempt to impact disease following exposures. Transient receptor potential (TRP) cation channels were identified as "particle sensors" in that their activation was coupled with the initiation of protective responses limiting airway deposition and inflammatory responses, which promote degradation and clearance of the particles. TRPA1, V1, V4, and M8 have a capacity to mediate adverse effects after exposure to combustion-generated particulate matter (PM); relative contributions of each depend upon particle composition, dose, and deposition. Exposure of human bronchial epithelial cells to an organic extract of diesel exhaust particle was followed by TRPV4 mediating Ca(++) influx, increased RAS expression, mitogen-activated protein kinase signaling, and matrix metalloproteinase-1 activation. These novel pathways of biological effect can be targeted by compounds that specifically inhibit critical signaling reactions. In addition to TRPs and calcium biochemistry, humic-like substances (HLS) and cell/tissue iron equilibrium were identified as potential mechanistic targets in lung injury after particle exposure. In respiratory epithelial cells, iron sequestration by HLS in wood smoke particle (WSP) was associated with oxidant generation, cell signaling, transcription factor activation, and release of inflammatory mediators. Similar to WSP, cytotoxic insoluble nanosized spherical particles composed of HLS were isolated from cigarette smoke condensate. Therapies that promote bioelimination of HLS and prevent the disruption of iron homeostasis could function to reduce the harmful effects of combustion-generated PM exposure.
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Affiliation(s)
| | - M. Ian Gilmour
- †U.S. Environmental Protection Agency, Durham, North Carolina
| | - Christopher A. Reilly
- ‡Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah; and
| | - Wolfgang Liedtke
- §Department of Medicine, Duke University, Durham, North Carolina
| | - Andrew J. Ghio
- †U.S. Environmental Protection Agency, Durham, North Carolina
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18
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Impairment of alveolar type-II cells involved in the toxicity of Aflatoxin G1 in rat lung. Food Chem Toxicol 2012; 50:3222-8. [DOI: 10.1016/j.fct.2012.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022]
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19
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Yu H, Li Q, Zhou X, Kolosov VP, Perelman JM. Transient receptor potential vanilloid 1 receptors mediate acid-induced mucin secretion via Ca2+ influx in human airway epithelial cells. J Biochem Mol Toxicol 2012; 26:179-86. [PMID: 22566028 DOI: 10.1002/jbt.20413] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/09/2011] [Accepted: 08/20/2011] [Indexed: 12/20/2022]
Abstract
Mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. Previous studies have reported that acids (gastroesophageal reflux or environmental exposure) induce many respiratory symptoms and are implicated in the pathophysiology of obstructive airway diseases. To understand these mechanisms, we measured acid-induced mucin secretion in human bronchial epithelial cells. In the present study, acid induced inward currents of transient receptor potential vanilloid (TRPV)1 and mucin 5AC (MUC5AC) secretion dose dependently, which were inhibited by TRPV1 antagonist capsazepine in a concentration-dependent manner. TRPV1 agonist capsaicin mediated a concentration-dependent increase in TRPV1 inward currents and MUC5AC secretion. Furthermore, capsaicin enhanced acid-induced TRPV1 inward currents and MUC5AC secretion. Acid-induced Ca(2+) influx was prevented by capsazepine dose dependently and enhanced by capsaicin. Pretreatment only with capsaicin also increased the Ca(2+) concentration in a concentration-dependent manner. These data suggest that pharmacological inhibition of calcium-permeable TRPV1 receptors could be used to prevent acid-induced mucin secretion, thereby providing a potential mechanism to reduce their toxicity.
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Affiliation(s)
- Hongmei Yu
- Division of Respiratory Medicine, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, People's Republic of China
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20
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Deering-Rice CE, Johansen ME, Roberts JK, Thomas KC, Romero EG, Lee J, Yost GS, Veranth JM, Reilly CA. Transient receptor potential vanilloid-1 (TRPV1) is a mediator of lung toxicity for coal fly ash particulate material. Mol Pharmacol 2011; 81:411-9. [PMID: 22155782 DOI: 10.1124/mol.111.076067] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 > diesel exhaust PM > crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4α (C4α), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue.
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21
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Gillespie P, Tajuba J, Lippmann M, Chen LC, Veronesi B. Particulate matter neurotoxicity in culture is size-dependent. Neurotoxicology 2011; 36:112-7. [PMID: 22057156 DOI: 10.1016/j.neuro.2011.10.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 10/19/2011] [Accepted: 10/20/2011] [Indexed: 12/19/2022]
Abstract
Exposure to particulate matter (PM) air pollution produces inflammatory damage to the cardiopulmonary system. This toxicity appears to be inversely related to the size of the PM particles, with the ultrafine particle being more inflammatory than larger sizes. Exposure to PM has more recently been associated with neurotoxicity. This study examines if the size-dependent toxicity reported in cardiopulmonary systems also occurs in neural targets. For this study, PM ambient air was collected over a 2 week period from Sterling Forest State Park (Tuxedo, New York) and its particulates sized as Accumulation Mode, Fine (AMF) (>0.18-1μm) or Ultrafine (UF) (<0.18μm) samples. Rat dopaminergic neurons (N27) were exposed to suspensions of each PM fraction (0, 12.5, 25, 50μm/ml) and cell loss (as measured by Hoechst nuclear stain) measured after 24h exposure. Neuronal loss occurred in response to all tested concentrations of UF (>12.5μg/ml) but was only significant at the highest concentration of AMF (50μg/ml). To examine if PM size-dependent neurotoxicity was retained in the presence of other cell types, dissociated brain cultures of embryonic rat striatum were exposed to AMF (80μg/ml) or UF (8.0μg/ml). After 24h exposure, a significant increase of reactive nitrogen species (nitrite) and morphology suggestive of apoptosis occurred in both treatment groups. However, morphometric analysis of neuron specific enolase staining indicated that only the UF exposure produced significant neuronal loss, relative to controls. Together, these data suggest that the inverse relationship between size and toxicity reported in cardiopulmonary systems occurs in cultures of isolated dopaminergic neurons and in primary cultures of the rat striatum.
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Affiliation(s)
- Patricia Gillespie
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States
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22
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Valverde MA, Cantero-Recasens G, Garcia-Elias A, Jung C, Carreras-Sureda A, Vicente R. Ion channels in asthma. J Biol Chem 2011; 286:32877-82. [PMID: 21799020 DOI: 10.1074/jbc.r110.215491] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ion channels are specialized transmembrane proteins that permit the passive flow of ions following their electrochemical gradients. In the airways, ion channels participate in the production of epithelium-based hydroelectrolytic secretions and in the control of intracellular Ca(2+) levels that will ultimately activate almost all lung cells, either resident or circulating. Thus, ion channels have been the center of many studies aiming to understand asthma pathophysiological mechanisms or to identify therapeutic targets for better control of the disease. In this minireview, we focus on molecular, genetic, and animal model studies associating ion channels with asthma.
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Affiliation(s)
- Miguel A Valverde
- Laboratory of Molecular Physiology and Channelopathies, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
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Deering-Rice CE, Romero EG, Shapiro D, Hughen RW, Light AR, Yost GS, Veranth JM, Reilly CA. Electrophilic components of diesel exhaust particles (DEP) activate transient receptor potential ankyrin-1 (TRPA1): a probable mechanism of acute pulmonary toxicity for DEP. Chem Res Toxicol 2011; 24:950-9. [PMID: 21591660 DOI: 10.1021/tx200123z] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Inhalation of environmental particulate matter (PM) is correlated with adverse health effects in humans, but gene products that couple detection with cellular responses, and the specific properties of PM that target different pathways, have not been fully elucidated. TRPA1 and V1 are two cation channels expressed by sensory neurons and non-neuronal cells of the respiratory tract that have been implicated as possible mediators of PM toxicity. The goals of this research were to determine if environmental PM preferentially activated TRPA1 and to elucidate the criteria responsible for selectivity. Quantification of TRPA1 activation by 4 model PM revealed that diesel exhaust PM (DEP) and coal fly ash PM (CFA1) were TRPA1 agonists at concentrations >0.077 mg/mL. DEP was more potent, and approximately 97% of the activity of DEP was recovered by serial extraction of the solid DEP with ethanol and hexane/n-butyl chloride. Modification of the electrophile/agonist binding sites on TRPA1 (C621, C641, C665, and K710) to non-nucleophilic residues reduced TRPA1 activation by DEP and abolished activation by DEP extracts as well as multiple individual electrophilic chemical components of DEP. However, responses to CFA1 and DEP solids were not affected by these mutations. Activity-guided fractionation of DEP and high resolution mass spectroscopy identified several new DEP-derived TRPA1 agonists, and activation of mouse dorsal root ganglion neurons demonstrated that TRPA1 is a primary target for DEP in a heterogeneous population of primary sensory nerves. It is concluded that TRPA1 is a specific target for electrophilic chemical components of DEP and proposed that activation of TRPA1 in the respiratory tract is likely to be an important mechanism for DEP pneumotoxicity.
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Affiliation(s)
- Cassandra E Deering-Rice
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, Utah 84112, United States
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Taylor-Clark TE, Undem BJ. Sensing pulmonary oxidative stress by lung vagal afferents. Respir Physiol Neurobiol 2011; 178:406-13. [PMID: 21600314 DOI: 10.1016/j.resp.2011.05.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 04/06/2011] [Accepted: 05/04/2011] [Indexed: 12/30/2022]
Abstract
Oxidative stress in the bronchopulmonary airways can occur through a variety of inflammatory mechanisms and also following the inhalation of environmental pollutants. Oxidative stress causes cellular dysfunction and thus mammals (including humans) have developed mechanisms for detecting oxidative stress, such that defensive behavior and defensive biological mechanisms can be induced to lessen its potential damage. Vagal sensory nerves innervating the airways play a critical role in the detection of the microenvironment in the airways. Oxidative stress and associated compounds activate unmyelinated bronchopulmonary C-fibers, initiating action potentials in these nerves that conduct centrally to evoke unpleasant sensations (e.g. urge to cough, dyspnea, chest-tightness) and to stimulate/modulate reflexes (e.g. cough, bronchoconstriction, respiratory rate, inspiratory drive). This review will summarize the published evidence regarding the mechanisms by which oxidative stress, reactive oxygen species, environmental pollutants and lipid products of peroxidation activate bronchopulmonary C-fibers. Evidence suggests a key role for transient receptor potential ankyrin 1 (TRPA1), although transient receptor potential vanilloid 1 (TRPV1) and purinergic P2X channels may also play a role. Knowledge of these pathways greatly aids our understanding of the role of oxidative stress in health and disease and represents novel therapeutic targets for diseases of the airways.
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Affiliation(s)
- Thomas E Taylor-Clark
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL 33612, United States.
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25
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The Role of Transient Receptor Potential Channels in Respiratory Symptoms and Pathophysiology. TRANSIENT RECEPTOR POTENTIAL CHANNELS 2011; 704:969-86. [DOI: 10.1007/978-94-007-0265-3_50] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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26
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Restrepo-Angulo I, De Vizcaya-Ruiz A, Camacho J. Ion channels in toxicology. J Appl Toxicol 2010; 30:497-512. [DOI: 10.1002/jat.1556] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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27
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Watterson TL, Hamilton B, Martin R, Coulombe RA. Urban particulate matter causes ER stress and the unfolded protein response in human lung cells. Toxicol Sci 2009; 112:111-22. [PMID: 19675143 DOI: 10.1093/toxsci/kfp186] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Because of its presumed adverse health effects, particulate air pollution (PM) has received growing attention, but the cellular mechanisms by which PM exerts toxicity are not well elucidated. PM has been associated with early mortality from illnesses that share endoplasmic reticulum (ER) stress as a mechanism of pathogenesis. In this study, we examined whether PM would induce the unfolded protein response (UPR) which is a cellular response to ER stress. Coarse (PM(10)) and fine (PM(2.5)) PM was collected from a single location in Northern Utah's Cache Valley during atmospheric inversions occurring in January 2002 and January 2003. Extracts of PM samples were added (12.5 and 25 microg/ml) to cultured human bronchial epithelial (BEAS-2B) cells for 24 h. At these concentrations neither PM nor LPS exhibited demonstrable cytotoxicity by the neutral red assay. However, PM elicited significant increases of unfolded protein response (UPR)-related post-translational modifications, such as S6 ribosomal protein, heat-shock protein (Hsp)27, and protein kinase related protein phosphorylation and cleavage of activating transcription factor (ATF)-6. PM exposure also resulted in significant increases in the UPR-associated proteins ATF-4, Hsp70, Hsp90, and binding immunoglobulin protein. PM also interfered with the export of Hsp70 from the cells in a concentration-dependent manner and resulted in release of C-reactive protein. Calpain was upregulated and activated in PM-treated cultures, though these events were not proapoptotic. This study demonstrates that PM is capable of inducing ER stress and the UPR in vitro and may be a mechanism by which PM exerts toxicity.
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Affiliation(s)
- Todd L Watterson
- Graduate Program in Toxicology, and Department of Veterinary Sciences, Utah State University, Logan, Utah 84322-4620
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28
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Colsoul B, Nilius B, Vennekens R. On the putative role of transient receptor potential cation channels in asthma. Clin Exp Allergy 2009; 39:1456-66. [PMID: 19624522 DOI: 10.1111/j.1365-2222.2009.03315.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The mammalian transient receptor potential (TRP) superfamily consists of 28 mammalian TRP cation channels, which can be subdivided into six main subfamilies: the TRPC ('Canonical'), TRPV ('Vanilloid'), TRPM ('Melastatin'), TRPP ('Polycystin'), TRPML ('Mucolipin') and the TRPA ('Ankyrin') groups. Increasing evidence has accumulated during the previous few years that links TRP channels to the cause of several diseases or to critically influence and/or determine their progress. This review focuses on the possible role of TRP channels in the aetiology of asthmatic lung disease.
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Affiliation(s)
- B Colsoul
- Laboratory Ion Channel Research, Department of Molecular Cell Biology, KU Leuven, Leuven, Belgium
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Peles S, Medda BK, Zhang Z, Banerjee B, Lehmann A, Shaker R, Sengupta JN. Differential effects of transient receptor vanilloid one (TRPV1) antagonists in acid-induced excitation of esophageal vagal afferent fibers of rats. Neuroscience 2009; 161:515-25. [PMID: 19324074 DOI: 10.1016/j.neuroscience.2009.03.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 02/17/2009] [Accepted: 03/17/2009] [Indexed: 12/17/2022]
Abstract
Gastro-esophageal acid reflux can stimulate esophageal vagal sensory afferents by activating proton-sensitive ion channel transient receptor vanilloid one (TRPV1). The objective of this study was to investigate the response characteristics of vagal afferent fibers of rats to acid (0.1 N HCl) and capsaicin (CAP) following esophagitis and differential effects of two classes of TRPV1 antagonists on responses of vagal afferent fibers. The chronic reflux was induced by ligating the fundus of the stomach and partial constriction of pylorus. Extracellular single fiber recordings were made from the cervical vagal afferent fibers from naive control and fundus-ligated (FL) esophagitis rats. Innervations of fibers were identified to esophageal distension (ED) and subsequently tested to CAP and acid before and after injection of TRPV1 antagonist JYL1421 or AMG9810 (10 micromol/kg i.v.). Seventy-five vagal afferent fibers from 70 rats were identified to ED. Intra-esophageal CAP (0.1 ml of 1 mg/ml) excited 39.5% (17/43, 5/22 from naive and 12/21 from FL rats) fibers. In contrast, i.v. injection of CAP (0.03-0.3 micromol/kg) dose-dependently excited 72% (42/58) fibers. Responses to CAP were significantly greater for fibers from FL rats (n=32) than naive rats (n=25). TRPV1 antagonists JYL1421 and AMG9810 (10 micromol/kg) significantly blocked response to CAP. Intra-esophageal acid infusion stimulated 5/17 (29.4%) fibers from naive rats and 12/28 (42%) from FL rats. Effect of acid was significantly blocked by AMG9810, but not by JYL1421. Results indicate that following esophagitis the number of fibers responsive to CAP and acid is greater than noninflamed esophagus, which may contribute to esophageal hypersensitivity. Acid-induced excitation of vagal sensory afferents can be differentially attenuated by different classes of TRPV1 antagonists. Therefore, TRPV1 antagonists play a key role in attenuation of hypersensitivity following reflux-induced esophagitis. The use of TRPV1 antagonists could be an alternative to the traditional symptoms-based treatment of chronic acid reflux and esophageal hypersensitivity.
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Affiliation(s)
- S Peles
- Division of Gastroenterology and Hepatology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Li J, Ghio AJ, Cho SH, Brinckerhoff CE, Simon SA, Liedtke W. Diesel exhaust particles activate the matrix-metalloproteinase-1 gene in human bronchial epithelia in a beta-arrestin-dependent manner via activation of RAS. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:400-9. [PMID: 19337515 PMCID: PMC2661910 DOI: 10.1289/ehp.0800311] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2008] [Accepted: 10/29/2008] [Indexed: 05/17/2023]
Abstract
BACKGROUND Diesel exhaust particles (DEPs) are globally relevant air pollutants that exert a detrimental human health impact. However, mechanisms of damage by DEP exposure to human respiratory health and human susceptibility factors are only partially known. Matrix metalloproteinase-1 (MMP-1) has been implied as an (etio)pathogenic factor in human lung and airway diseases such as emphysema, chronic obstructive pulmonary disease, chronic asthma, tuberculosis, and bronchial carcinoma and has been reported to be regulated by DEPs. OBJECTIVE We elucidated the molecular mechanisms of DEPs' up-regulation of MMP-1. METHODS/RESULTS Using permanent and primary human bronchial epithelial (HBE) cells at air-liquid interface, we show that DEPs activate the human MMP-1 gene via RAS and subsequent activation of RAF-MEK-ERK1/2 mitogen-activated protein kinase signaling, which can be scaffolded by beta-arrestins. Short interfering RNA mediated beta-arrestin1/2 knockout eliminated formation, subsequent nuclear trafficking of phosphorylated ERK1/2, and resulting MMP-1 transcriptional activation. Transcriptional regulation of the human MMP-1 promoter was strongly influenced by the presence of the -1607GG polymorphism, present in 60-80% of humans, which led to striking up-regulation of MMP-1 transcriptional activation. CONCLUSION Our results confirm up-regulation of MMP-1 in response to DEPs in HBE and provide new mechanistic insight into how these epithelia, the first line of protection against environmental insults, up-regulate MMP-1 in response to DEP inhalation. These mechanisms include a role for the human -1607GG polymorphism as a susceptibility factor for an accentuated response, which critically depends on the ability of beta-arrestin1/2 to generate scaffolding and nuclear trafficking of phosphorylated ERK1/2.
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Affiliation(s)
- Jinju Li
- Department of Neurobiology, Duke University, Durham, North Carolina, USA
| | - Andrew J. Ghio
- U.S. Environmental Protection Agency, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Seung-Hyun Cho
- U.S. Environmental Protection Agency, Research Triangle Park, Research Triangle Park, North Carolina, USA
| | - Constance E. Brinckerhoff
- Departments of Medicine and Biochemistry, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Sidney A. Simon
- Department of Neurobiology, Duke University, Durham, North Carolina, USA
- Center for Neuroengineering and
| | - Wolfgang Liedtke
- Department of Neurobiology, Duke University, Durham, North Carolina, USA
- Division of Neurology, Department of Medicine, Duke University, Durham, North Carolina, USA
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31
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Materazzi S, Nassini R, Gatti R, Trevisani M, Geppetti P. Cough sensors. II. Transient receptor potential membrane receptors on cough sensors. Handb Exp Pharmacol 2009:49-61. [PMID: 18825335 DOI: 10.1007/978-3-540-79842-2_3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The transient receptor potential (TRP) family of channels is represented by at least six members in primary sensory neurons. These include the TRP vanilloid subtypes 1 (TRPV1), 2, 3, and 4, the cold and menthol receptor TRPM8, and TRPA1. Much interest has been directed to the study of the TRPV1, because capsaicin has been instrumental in discovering the unique role of a subset of primary sensory neurons in causing nociceptive responses, in activating reflex pathways including cough, and in producing neurogenic inflammation. TRPV1 is now regarded as an integrator of diverse sensory modalities because it undergoes marked plasticity and sensitization through a variety of mechanisms, including activation of G-protein-coupled or tyrosine kinase receptors. Evidence in experimental animals and in patients with airway diseases indicates a marked hypersensitivity to cough induced by TRPV1 agonists. Recent studies with newly developed high-affinity and selective TRPV1 antagonists have revealed that TRPV1 inhibition reduces cough induced by citric acid or antigen challenge.
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Affiliation(s)
- S Materazzi
- Department of Critical Care Medicine and Surgery, University of Florence, Viale Pieraccini, 6, Florence 50139, Italy
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32
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Franco R, Sánchez-Olea R, Reyes-Reyes EM, Panayiotidis MI. Environmental toxicity, oxidative stress and apoptosis: ménage à trois. Mutat Res 2008; 674:3-22. [PMID: 19114126 DOI: 10.1016/j.mrgentox.2008.11.012] [Citation(s) in RCA: 345] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 11/27/2008] [Indexed: 12/21/2022]
Abstract
Apoptosis is an evolutionary conserved homeostatic process involved in distinct physiological processes including organ and tissue morphogenesis, development and senescence. Its deregulation is also known to participate in the etiology of several human diseases including cancer, neurodegenerative and autoimmune disorders. Environmental stressors (cytotoxic agents, pollutants or toxicants) are well known to induce apoptotic cell death and to contribute to a variety of pathological conditions. Oxidative stress seems to be the central element in the regulation of the apoptotic pathways triggered by environmental stressors. In this work, we review the established mechanisms by which oxidative stress and environmental stressors regulate the apoptotic machinery with the aim to underscore the relevance of apoptosis as a component in environmental toxicity and human disease progression.
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Affiliation(s)
- Rodrigo Franco
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, P. O. Box 12233, 111. T.W. Alexander Drive, Research Triangle Park, NC 27709, United States.
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33
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Is TRPV1 a useful target in respiratory diseases? Pulm Pharmacol Ther 2008; 21:833-9. [PMID: 18992356 DOI: 10.1016/j.pupt.2008.09.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 09/15/2008] [Accepted: 09/24/2008] [Indexed: 11/23/2022]
Abstract
This review focuses on the transient receptor potential vanilloid 1 (TRPV1). TRPV1 is a non-selective cation channel predominantly expressed in the cell membranes of sensory afferent fibers, which are activated multi-modally. In the mammalian respiratory system, immunohistochemical and electrophysiological studies have revealed heterogeneous localizations of TRPV1 channels in the airways and their presence in pleural afferents. TRPV1 channels in afferents are not only involved with sensory inputs, but also release several neuropeptides upon stimulation. These processes trigger pathophysiological effects (e.g. reflex bronchoconstriction, hypersecretion, cough, etc.) that cause various symptoms of airway diseases. Recent studies have identified several endogenous and exogenous substances that can activate TRPV1 in the lung. Because of its key role in initiating inflammatory processes, TRPV1 receptor antagonists have been proposed as therapeutic candidates. Therefore, a critical update of recent therapeutic results is also given in this review.
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Methyl tert-butyl ether (MTBE) induced Ca(2+)-dependent cytotoxicity in isolated rabbit tracheal epithelial cells. Toxicol In Vitro 2008; 22:1734-41. [PMID: 18715547 DOI: 10.1016/j.tiv.2008.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 06/19/2008] [Accepted: 07/21/2008] [Indexed: 12/17/2022]
Abstract
As a volatile synthetic organic chemical, methyl tert-butyl ether (MTBE) was the most common gasoline additive. The increasing use of MTBE raised concern over its health safety. Inhalation was the principle route of exposure for the general population. This study used a model of rabbit tracheal epithelial cells (RTEs) in primary culture to investigate the cytotoxic effects induced by MTBE and the potential mechanism. RTEs were incubated with medium alone (control), 0.5, 50, 5000ppm MTBE respectively. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazo liumbromide) assay, staining with fluorescein diacetate, propidium iodide and lactate dehydrogenase leakage ratio were used to assess MTBE cytotoxicity on cells. We also observed a significant elevation in cytosolic Ca2+ by fluorescence probe Fluo-3AM at 3, 6 and 12h following exposure to MTBE. Loss of mitochondrial membrane potential (MMP) was detected following 12 and 24h treatment of NP and assessment by rhodamine 123 (Rh123) staining. Activity changes of the Ca(2+)-ATPase, Ca(2+)-Mg(2+)-ATPase following MTBE treatment displayed a similar trend, suggesting an initial elevation before 6h and subsequent dramatic decrease at 12h. Our results demonstrated that induction of cell injury, associated with mitochondrial dysfunction, and alterations in cytosolic Ca2+ in RTEs represent key mechanisms by which MTBE exerts its cytotoxic effects.
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35
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Sappington RM, Calkins DJ. Contribution of TRPV1 to microglia-derived IL-6 and NFkappaB translocation with elevated hydrostatic pressure. Invest Ophthalmol Vis Sci 2008; 49:3004-17. [PMID: 18362111 DOI: 10.1167/iovs.07-1355] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE The authors investigated the contributions of the transient receptor potential vanilloid-1 receptor (TRPV1) and Ca(2+) to microglial IL-6 and nuclear factor kappa B (NFkappaB) translocation with elevated hydrostatic pressure. METHODS The authors first examined IL-6 colocalization with the microglia marker Iba-1 in the DBA/2 mouse model of glaucoma to establish relevance. They isolated microglia from rat retina and maintained them at ambient or elevated (+70 mm Hg) hydrostatic pressure in vitro and used ELISA and immunocytochemistry to measure changes in the IL-6 concentration and NFkappaB translocation induced by the Ca(2+) chelator EGTA, the broad-spectrum Ca(2+) channel inhibitor ruthenium red, and the TRPV1 antagonist iodo-resiniferatoxin (I-RTX). They applied the Ca(2+) dye Fluo-4 AM to measure changes in intracellular Ca(2+) at elevated pressure induced by I-RTX and confirmed TRPV1 expression in microglia using PCR and immunocytochemistry. RESULTS In DBA/2 retina, elevated intraocular pressure increased microglial IL-6 in the ganglion cell layer. Elevated hydrostatic pressure (24 hours) increased microglial IL-6 release, cytosolic NFkappaB, and NFkappaB translocation in vitro. These effects were reduced substantially by EGTA and ruthenium red. Antagonism of TRPV1 in microglia partially inhibited pressure-induced increases in IL-6 release and NFkappaB translocation. Brief elevated pressure (1 hour) induced a significant increase in microglial intracellular Ca(2+) that was partially attenuated by TRPV1 antagonism. CONCLUSIONS Elevated pressure induces an influx of extracellular Ca(2+) in retinal microglia that precedes the activation of NFkappaB and the subsequent production and release of IL-6 and is at least partially dependent on the activation of TRPV1 and other ruthenium red-sensitive channels.
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Affiliation(s)
- Rebecca M Sappington
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0654, USA
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36
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Abstract
1. Cough is a primary defensive reflex that protects the airways from potentially harmful stimuli. 2. During many respiratory diseases, the cough reflex threshold is lowered and coughing becomes excessive. 3. Currently available therapeutics are mostly ineffective at suppressing excessive coughing. 4. In the present review, we describe the sensory neural pathways involved in cough, how these pathways may become dysfunctional in airway disease and the most recent advances that have been made in identifying future targets for cough suppression.
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Affiliation(s)
- Stuart B Mazzone
- Howard Florey Institute, University of Melbourne, Melbourne, Victoria, Australia.
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37
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Faisy C, Planquette B, Naline E, Risse PA, Frossard N, Fagon JY, Advenier C, Devillier P. Acid-induced modulation of airway basal tone and contractility: Role of acid-sensing ion channels (ASICs) and TRPV1 receptor. Life Sci 2007; 81:1094-102. [PMID: 17869310 DOI: 10.1016/j.lfs.2007.08.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 08/24/2007] [Accepted: 08/27/2007] [Indexed: 12/28/2022]
Abstract
The role of extracellular acidosis in inflammatory airway diseases is not well known. One consequence of tissue acidification is the stimulation of sensory nerves via the polymodal H(+)-gated transmembrane channels ASICs and TRPV1 receptor. The present study investigated the effect of acidosis on airway basal tone and responsiveness in the guinea pig. Acidosis (pH 6.8, 10 min, 37 degrees C) significantly decreased the basal tone of tracheal rings (p<0.01 vs. paired control). Moreover, pH fall raised the maximal contraction of tracheal rings to acetylcholine (p<0.05 vs. paired control). The pH-induced relaxation of airway basal tone was inhibited by pretreatments with ASIC1a or ASIC3/ASIC2a inhibitors (0.5 mM ibuprofen, 0.1 mM gadolinium), nitric oxide synthase inhibitor (1 mM L-NAME), and guanylate cyclase inhibitor (1 microM ODQ). In contrast, the pH-induced relaxation of airway basal tone was not modified by epithelium removal or pretreatments with a TRPV1 antagonist (1 microM capsazepine), a combination of NK(1,2,3) receptor antagonists (0.1 microM each), a blocker of voltage-sensitive Na(+) channels (1 microM tetrodotoxin), a cyclooxygenase inhibitor with no activity on ASICs (1 microM indomethacin) or ASIC3 and ASIC3/ASIC2b inhibitors (10 nM diclofenac, 1 microM aspirin). Furthermore, acid-induced hyperresponsiveness to acetylcholine was inhibited by epithelium removal, capsazepine, NK(1,2,3) receptor antagonists, tetrodotoxin, amiloride, ibuprofen and diclofenac. In summary, the initial pH-induced airway relaxation seems to be independent of sensory nerves, suggesting a regulation of airway basal tone mediated by smooth muscle ASICs. Conversely, the pH-induced hyperresponsiveness involves sensory nerves-dependent ASICs and TRPV1, and an unknown epithelial component in response to acidosis.
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Affiliation(s)
- Christophe Faisy
- Research Unit UPRES EA220, Université Versailles Saint Quentin, Hôpital Foch, 40 rue Worth, 92150 Suresnes, France.
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Kim D, Baraniuk JN. Sensing the air around us: the voltage-gated-like ion channel family. Curr Allergy Asthma Rep 2007; 7:85-92. [PMID: 17437677 DOI: 10.1007/s11882-007-0004-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ion channels are a complex set of proteins having many important physiologic and potentially pathologic roles. The flow of ions through these channels and the subsequent cellular depolarization can trigger complex mechanisms such as cardiac rhythm, hormone secretion, and numerous sensory experiences. The transient receptor potential (TRP) channels are an important means for multiple organ systems to interact with their environment. The various TRP channel subfamilies respond to voltage or to ligands such as G-protein coupled receptors. Their ability to sense temperature, pain, stretch, and osmolarity among others enables them to mediate responses such as smooth muscle contraction, cough, or sensation of pain.
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Affiliation(s)
- Dennis Kim
- Division of Rheumatology, Immunology and Allergy, Room B105, Lower Level Kober-Cogen Building, Georgetown University, 3800 Reservoir Road, NW, Washington, DC 20007-2197, USA
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Nilius B, Owsianik G, Voets T, Peters JA. Transient receptor potential cation channels in disease. Physiol Rev 2007; 87:165-217. [PMID: 17237345 DOI: 10.1152/physrev.00021.2006] [Citation(s) in RCA: 1035] [Impact Index Per Article: 60.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The transient receptor potential (TRP) superfamily consists of a large number of cation channels that are mostly permeable to both monovalent and divalent cations. The 28 mammalian TRP channels can be subdivided into six main subfamilies: the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), and the TRPA (ankyrin) groups. TRP channels are expressed in almost every tissue and cell type and play an important role in the regulation of various cell functions. Currently, significant scientific effort is being devoted to understanding the physiology of TRP channels and their relationship to human diseases. At this point, only a few channelopathies in which defects in TRP genes are the direct cause of cellular dysfunction have been identified. In addition, mapping of TRP genes to susceptible chromosome regions (e.g., translocations, breakpoint intervals, increased frequency of polymorphisms) has been considered suggestive of the involvement of these channels in hereditary diseases. Moreover, strong indications of the involvement of TRP channels in several diseases come from correlations between levels of channel expression and disease symptoms. Finally, TRP channels are involved in some systemic diseases due to their role as targets for irritants, inflammation products, and xenobiotic toxins. The analysis of transgenic models allows further extrapolations of TRP channel deficiency to human physiology and disease. In this review, we provide an overview of the impact of TRP channels on the pathogenesis of several diseases and identify several TRPs for which a causal pathogenic role might be anticipated.
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Affiliation(s)
- Bernd Nilius
- Department of Physiology, Campus Gasthuisberg, KULeuven, Leuven, Belgium.
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40
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Jia Y, Lee LY. Role of TRPV receptors in respiratory diseases. Biochim Biophys Acta Mol Basis Dis 2007; 1772:915-27. [PMID: 17346945 DOI: 10.1016/j.bbadis.2007.01.013] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 01/23/2007] [Accepted: 01/24/2007] [Indexed: 12/24/2022]
Abstract
Transient receptor potential vanilloid type channels (TRPVs) are expressed in several cell types in human and animal lungs. Increasing evidence has demonstrated important roles of these cation channels, particularly TRPV1 and TRPV4, in the regulation of airway function. These TRPVs can be activated by a number of endogenous substances (hydrogen ion, certain lipoxygenase products, etc.) and changes in physiological conditions (e.g., temperature, osmolarity, etc.). Activation of these channels can evoke Ca(2+) influx and excitation of the neuron. TRPV1 channels are generally expressed in non-myelinated afferents innervating the airways and lungs, which also contain sensory neuropeptides such as tachykinins. Upon stimulation, these sensory nerves elicit centrally-mediated reflex responses as well as local release of tachykinins, and result in cough, airway irritation, reflex bronchoconstriction and neurogenic inflammation in the airways. Recent studies clearly demonstrated that the excitability of TRPV1 channels is up-regulated by certain autacoids (e.g., prostaglandin E(2), bradykinin) released during airway inflammatory reaction. Under these conditions, the TRPV1 can be activated by a slight increase in airway temperature or tissue acidity. Indirect evidence also suggests that TRPV channels may play a part in the pathogenesis of certain respiratory diseases such as asthma and chronic cough. Therefore, the potential use of TRPV antagonists as a novel therapy for these diseases certainly merits further investigation.
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Affiliation(s)
- Yanlin Jia
- Neurobiology, Schering-Plough Research Institute, Kenilworth, NJ 07033, USA
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Seki N, Shirasaki H, Kikuchi M, Himi T. Capsaicin induces the production of IL-6 in human upper respiratory epithelial cells. Life Sci 2007; 80:1592-7. [PMID: 17306835 DOI: 10.1016/j.lfs.2007.01.037] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 01/11/2007] [Accepted: 01/18/2007] [Indexed: 11/16/2022]
Abstract
Capsaicin, a type of alkaloid and the pungent component of chili peppers, is used as a therapeutic drug against allergic rhinitis and also as an index of bronchial hypersensitivity. Capsaicin receptor (TRPV1) expression has been identified in non-neuronal cells as well as neuronal cells. In our previous study, both TRPV1 protein and its gene expression on nasal epithelial cells were confirmed by immunohistochemistry and RT-PCR, respectively. In order to clarify whether or not TRPV1 acts as a functional receptor, we examined the effects of capsaicin on the production of IL-6 from primary cultured human airway epithelial cells at both protein and mRNA levels. Human nasal epithelial cells (HNECs) and normal human bronchial/tracheal epithelial cells (NHBE cells) were stimulated with increasing concentrations of capsaicin and/or pretreatment with capsazepine (TRPV1 antagonist) at 37 degrees C. The supernatant and total RNA were collected at 0, 4, 12, 24 and 48 h after treatment. IL-6 concentration and the IL-6 mRNA level were evaluated by ELISA and real-time PCR, respectively. Capsaicin (10 nM-10 muM) induced production of IL-6 from HNECs and NHBE cells and this effect was inhibited by pretreatment with capsazepine. Our findings suggest that topical application of capsaicin to the airway induces IL-6 production from respiratory epithelial cells via activation of TRPV1.
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Affiliation(s)
- Nobuhiko Seki
- Department of Otolaryngology, Sapporo Medical University School of Medicine, S1W16, Chuo-ku, Sapporo 060-8543, Japan.
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Szallasi A, Cruz F, Geppetti P. TRPV1: a therapeutic target for novel analgesic drugs? Trends Mol Med 2006; 12:545-54. [PMID: 16996800 DOI: 10.1016/j.molmed.2006.09.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 08/15/2006] [Accepted: 09/08/2006] [Indexed: 02/03/2023]
Abstract
The vanilloid receptor TRPV1 is now recognized as a molecular integrator of painful stimuli ranging from noxious heat to endovanilloids in inflammation. Pharmacological blockade of TRPV1 represents a new strategy in pain relief. TRPV1 antagonists are expected to prevent pain by silencing receptors where pain is generated rather than stopping the propagation of pain, as most-traditional pain killers do. This hypothesis has already being tested in the clinic by administering small molecule TRPV1 antagonists (e.g. GlaxoSmithKline SB-705498) for migraine and dental pain. Paradoxically, in some murine models of chronic pain, TRPV1-deficient mice exhibit more pain-related behavior than their wild-type littermates, indicating that the understanding of TRPV1 in pain is still incomplete. Moreover, there is mounting evidence to suggest the existence of functional TRPV1 both in the brain and in various non-neuronal tissues. The biological role of these receptors remains elusive, but their tissue distribution clearly indicates that they are involved in many more functions than just pain perception. Here, we review the potential therapeutic indications and adverse effects of TRPV1 antagonists.
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Affiliation(s)
- Arpad Szallasi
- Departments of Pathology, Monmouth Medical Center, Long Branch, NJ 07740, USA.
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43
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Szallasi A. Small molecule vanilloid TRPV1 receptor antagonists approaching drug status: can they live up to the expectations? Naunyn Schmiedebergs Arch Pharmacol 2006; 373:273-86. [PMID: 16773387 DOI: 10.1007/s00210-006-0072-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2006] [Accepted: 04/10/2006] [Indexed: 01/05/2023]
Abstract
The cloning of the transient receptor potential vanilloid type-1 (TRPV1) receptor initiated the discovery of potent small molecule antagonists, many of which are in preclinical phase or already undergoing clinical trials. While animal experiments imply a therapeutic value for these compounds as novel analgesic-antiphlogistic drugs, new findings with TRPV1 deficient (trpv1 -/-) mice signal troubles for TRPV1 antagonists as clinical research gains impetus. An emerging concept with important implications for drug development is that TRPV1 may be differentially regulated under physiological and pathological conditions. If so, it is conceivable that such TRPV1 ligands can be synthesized that specifically target TRPV1 in diseased (e.g. inflamed or neoplastic) tissues but spare TRPV1 that subserves its physiological functions in healthy organs. This review explores the current status of this field and seeks an answer to the question how these new discoveries could be factored into TRPV1 drug discovery and development.
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Affiliation(s)
- Arpad Szallasi
- Department of Pathology, Monmouth Medical Center, 300 Second Avenue, Long Branch, NJ 07740, USA.
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44
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Franco R, Bortner CD, Cidlowski JA. Potential Roles of Electrogenic Ion Transport and Plasma Membrane Depolarization in Apoptosis. J Membr Biol 2006; 209:43-58. [PMID: 16685600 DOI: 10.1007/s00232-005-0837-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Indexed: 12/15/2022]
Abstract
Apoptosis is characterized by the programmed activation of specific biochemical pathways leading to the organized demise of cells. To date, aspects of the intracellular signaling machinery involved in this phenomenon have been extensively dissected and characterized. However, recent studies have elucidated a novel role for changes in the intracellular milieu of the cells as important modulators of the cell death program. Specially, intracellular ionic homeostasis has been reported to be a determinant in both the activation and progression of the apoptotic cascade. Several apoptotic insults trigger specific changes in ionic gradients across the plasma membrane leading to depolarization of the plasma membrane potential (PMP). These changes lead to ionic imbalance early during apoptosis. Several studies have also suggested the activation and/or modulation of specific ionic transport mechanisms including ion channels, transporters and ATPases, as mediators of altered intracellular ionic homeostasis leading to PMP depolarization during apoptosis. However, the role of PMP depolarization and of the changes in ionic homeostasis during the progression of apoptosis are still unclear. This review summarizes the current knowledge regarding the causes and consequences of PMP depolarization during apoptosis. We also review the potential electrogenic ion transport mechanisms associated with this event, including the net influx/efflux of cations and anions. An understanding of these mechamisms could lead to the generation of new therapeutic approaches for a variety of diseases involving apoptosis.
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Affiliation(s)
- R Franco
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Geppetti P, Materazzi S, Nicoletti P. The transient receptor potential vanilloid 1: role in airway inflammation and disease. Eur J Pharmacol 2006; 533:207-14. [PMID: 16464449 DOI: 10.1016/j.ejphar.2005.12.063] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 12/25/2022]
Abstract
The transient receptor potential vanilloid 1 (TRPV1) is an excitatory cation channel, rather selectively expressed in a subpopulation of nociceptive, primary sensory neurons that promote neurogenic inflammation via neuropeptide release. TRPV1 is activated by noxious temperature, low extracellular pH and diverse lipid derivatives, and is uniquely sensitive to vanilloid molecules, including capsaicin. TRPV1 expression and sensitivity is highly regulated by diverse G protein-coupled and tyrosine kinase receptors. Other exogenous or endogenous chemical agents, including reactive oxygen species, ethanol and hydrogen sulphide sensitize/activate TRPV1. In the airways, TRPV1 agonists cause cough, bronchoconstriction, microvascular leakage, hyperreactivity and hypersecretion. Patients with asthma and chronic obstructive pulmonary disease are more sensitive to the tussive effect of TRPV1 agonists and TRPV1 activation may contribute to respiratory symptoms caused by acidic media present in the airways during asthma exacerbation, gastroesophageal reflux induced asthma or in other conditions. TRPV1 antagonists may be useful in the treatment of these diseases.
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Affiliation(s)
- Pierangelo Geppetti
- Clinical Pharmacology Unit, Department of Critical Care Medicine and Surgery, University of Florence, Italy.
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Reilly CA, Johansen ME, Lanza DL, Lee J, Lim JO, Yost GS. Calcium-dependent and independent mechanisms of capsaicin receptor (TRPV1)-mediated cytokine production and cell death in human bronchial epithelial cells. J Biochem Mol Toxicol 2005; 19:266-75. [PMID: 16173059 PMCID: PMC2291358 DOI: 10.1002/jbt.20084] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Activation of the capsaicin receptor (VR1 or TRPV1) in bronchial epithelial cells by capsaicinoids and other vanilloids promotes pro-inflammatory cytokine production and cell death. The purpose of this study was to investigate the role of TRPV1-mediated calcium flux from extracellular sources as an initiator of these responses and to define additional cellular pathways that control cell death. TRPV1 antagonists and reduction of calcium concentrations in treatment solutions attenuated calcium flux, induction of interleukin-6 and 8 gene expression, and IL-6 secretion by cells treated with capsaicin or resiniferatoxin. Most TRPV1 antagonists also attenuated cell death, but the relative potency and extent of protection did not directly correlate with inhibition of total calcium flux. Treatment solutions with reduced calcium content or chelators had no effect on cytotoxicity. Inhibitors of arachidonic acid metabolism and cyclo-oxygenases also prevented cell death indicating that TRPV1 agonists disrupted basal arachidonic acid metabolism and altered cyclo-oxygenase function via a TRPV1-dependent mechanism in order to produce toxicity. These data confirm previous results demonstrating calcium flux through TRPV1 acts as a trigger for cytokine production by vanilloids, and provides new mechanistic insights on mechanisms of cell death produced by TRPV1 agonists in respiratory epithelial cells.
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Affiliation(s)
- Christopher A. Reilly
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Mark E. Johansen
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Diane L. Lanza
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
| | - Jeewoo Lee
- College of Pharmacy, Seoul National University, Shinlim-Dong, Kwanak-Ku, Seoul 151-742, Korea
| | - Ju-Ok Lim
- College of Pharmacy, Seoul National University, Shinlim-Dong, Kwanak-Ku, Seoul 151-742, Korea
| | - Garold S. Yost
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; E-mail:
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Van Vleet TR, Watterson TL, Klein PJ, Coulombe RA. Aflatoxin B1 alters the expression of p53 in cytochrome P450-expressing human lung cells. Toxicol Sci 2005; 89:399-407. [PMID: 16280384 DOI: 10.1093/toxsci/kfj039] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Aflatoxin B1 (AFB1) is a potent dietary hepatocarcinogen in animals and probably in humans. Mutations (and altered expression) of the tumor suppresser gene p53 have been observed in liver tumors from patients exposed to high dietary AFB1. Inhalation of AFB1-laden grain dusts has been associated with an increased incidence of lung cancer in humans as well. We examined the effects of low concentrations of AFB1 on the expression of p53 and MDM2 in human bronchial epithelial cells (BEAS-2B) transfected with cDNA for either cytochrome P450 (CYP) 1A2 (B-CMV1A2) or CYP 3A4 (B3A4), two isozymes that are responsible for AFB1 activation in human liver and possibly the lung. Untreated B-CMV1A2 and B3A4 cells constitutively expressed p53. Exposure to a range (0.015-15 microM for 30 min) of AFB1 concentrations caused a concentration-dependent decline in p53 expression in B-CMV1A2 cells, and to a lesser extent, in B3A4 cells. The AFB1-mediated decrease in p53 continued for at least 12 h after 30-min exposures to 1.5 muM AFB(1). Mirroring the decrease in p53 expression was a concentration-dependent increase in the expression of the 76-kDa MDM2 isoform in B-CMV1A2 and B-3A4 cells. Interestingly, AFB1 did not induce DNA laddering, an indicator of apoptotic cell death, but proteolytic activation of caspase-3 was detected in AFB1-treated B-CVM1A2 cells. In total, these data show that low, environmentally-relevant concentrations of AFB1 alter the expression of p53 and MDM2 in these human lung cells, and that cells that stably express CYP 1A2 were more susceptible to this effect than nontransfected, or 3A4-expressing cells.
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Affiliation(s)
- Terry R Van Vleet
- Graduate Program in Toxicology, and Department of Veterinary Sciences, Utah State University, Logan, UT 84322-4620, USA
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Johansen ME, Reilly CA, Yost GS. TRPV1 antagonists elevate cell surface populations of receptor protein and exacerbate TRPV1-mediated toxicities in human lung epithelial cells. Toxicol Sci 2005; 89:278-86. [PMID: 16120755 PMCID: PMC2291391 DOI: 10.1093/toxsci/kfi292] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
TRPV1 mediates cell death and pro-inflammatory cytokine production in lung epithelial cells exposed to prototypical receptor agonists. This study shows that NHBE, BEAS-2B and TRPV1 over-expressing BEAS-2B cells pre-treated with various TRPV1 antagonists become sensitized to the prototypical TRPV1 agonist, nonivamide, via a mechanism that involves translocation of existing receptor from the endoplasmic reticulum to the plasma membrane. As such, typical cellular responses to agonist treatment, as measured by calcium flux, inflammatory cytokine gene induction, and cytotoxicity were exacerbated. These data were in contrast to the results obtained when TRPV1 antagonists were co-administered with nonivamide; conditions which inhibited TRPV1-mediated effects. The antagonists LJO-328, SC0030, and capsazepine increased the cytotoxicity of nonivamide by approximately 20-fold and agonist-induced calcium flux by approximately 6-fold. Inflammatory-cytokine gene induction by nonivamide was also increased significantly by pre-treatment with the antagonists. The enhanced responses were inhibited by the co-administration of antagonists with nonivamide, confirming that increases in sensitivity were attributable to increased TRPV1-associated activity. Sensitization was attenuated by brefeldin A (a golgi transport inhibitor), but not cycloheximide (a protein synthesis inhibitor), or actinomycin D (a transcription inhibitor). Sensitized cells exhibited increased calcium flux from extracellular calcium sources, while unsensitized cells exhibited calcium flux originating primarily from intracellular stores. These results demonstrate the presence of a novel mechanism for regulating the sub-cellular distribution of TRPV1 and subsequent control of cellular sensitivity to TRPV1 agonists.
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Affiliation(s)
| | - Christopher A. Reilly
- To whom correspondence should be addressed at University of Utah, Department of Pharmacology and Toxicology, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112. Fax: (801) 585-3945. E-mail:
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Abstract
The mammalian TRP (transient receptor potential) family consists of six main subfamilies termed the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), and TRPA (ankyrin) groups. These subfamilies encompass 28 ion channels that function as diverse cellular sensors. All of the channels are permeable to monovalent cations, and most are also permeable to Ca(2+). There are strong indications that TRP channels are involved in many diseases. At this point, four channelopathies have been identified in which a defect in a TRP channel-encoding gene is the direct cause of disease. TRPs are also involved in some systemic diseases because of their role as receptors for irritants, inflammation products, and xenobiotic toxins. Other indications of the involvement of TRPs in several diseases come from correlations between the levels of channel expression and disease symptoms or from the mapping of TRP-encoding genes to susceptible chromosome regions. Finally, the phenotypes of TRP knockout mice and other transgenic models allow a degree of extrapolation to human diseases. We present an overview of current knowledge about the role of TRP channels in human disease and highlight some TRP "suspects" for which a role in disease can be anticipated. An understanding of the genetics of disease may lead to the development of targeted new therapies.
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Affiliation(s)
- Bernd Nilius
- Department of Physiology, Campus Gasthuisberg Katholieke Universiteit, Leuven, Belgium.
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Watanabe N, Horie S, Michael GJ, Spina D, Page CP, Priestley JV. Immunohistochemical localization of vanilloid receptor subtype 1 (TRPV1) in the guinea pig respiratory system. Pulm Pharmacol Ther 2005; 18:187-97. [PMID: 15707853 DOI: 10.1016/j.pupt.2004.12.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 12/02/2004] [Accepted: 12/03/2004] [Indexed: 12/22/2022]
Abstract
Transient receptor potential vanilloid-1 (TRPV1) containing nerves are implicated in cough and bronchoconstriction although the significance of their documentation on non-neuronal cells is unclear. We have investigated the anatomical distribution and location of TRPV1 in an animal species often utilized in models of cough and airway inflammation. The distribution and localization of TRPV1 immunoreactivity in the lung was studied using confocal microscopy. Double labelling were carried out using the panaxonal marker, protein gene product 9.5 (PGP) and the neuropeptide substance P. TRPV1 was localized to fine axons within the epithelium of the trachea, however this represented only a fraction of the total axonal innervation of the epithelium. TRPV1 immunoreactive axons were also found in and around subepithelial regions of the airways, including smooth muscle and blood vessels and within the lower airways, found in the vicinity of bronchi and bronchioles, and in and around alveolar tissue. TRPV1 in the epithelium of the trachea was co-localized with substance P containing axons, although TRPV1 immunoreactive neuropeptide negative axons were also discernible. We found evidence for TRPV1 localization to axons throughout the respiratory tract. The distribution was heterogeneous and represented a fraction of the total neuronal innervation of the airways. No TRPV1 was found localized to airway epithelial cells. TRPV1 was often co-localized with the sensory neuropeptide substance P but there was evidence of TRPV1 positive neurones that did not express substance P. This suggests a role for TRPV1 in the airway that is independent of sensory neuropeptides.
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Affiliation(s)
- Naoto Watanabe
- Sackler Institute of Pulmonary Pharmacology, Pharmaceutical Science Division, Kings College, Guys Campus, St Thomas Street, London SE1 1UL, UK
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