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Mainguy-Seers S, Boivin R, Pourali Dogaheh S, Beaudry F, Hélie P, Bonilla AG, Martin JG, Lavoie JP. Effects of azithromycin on bronchial remodeling in the natural model of severe neutrophilic asthma in horses. Sci Rep 2022; 12:446. [PMID: 35013387 PMCID: PMC8748876 DOI: 10.1038/s41598-021-03955-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 12/06/2021] [Indexed: 11/09/2022] Open
Abstract
Steroid resistance in asthma has been associated with neutrophilic inflammation and severe manifestations of the disease. Macrolide add-on therapy can improve the quality of life and the exacerbation rate in refractory cases, possibly with greater effectiveness in neutrophilic phenotypes. The mechanisms leading to these beneficial effects are incompletely understood and whether macrolides potentiate the modulation of bronchial remodeling induced by inhaled corticosteroids (ICS) is unknown. The objective of this study was to determine if adding azithromycin to ICS leads to further improvement of lung function, airway inflammation and bronchial remodeling in severe asthma. The combination of azithromycin (10 mg/kg q48h PO) and inhaled fluticasone (2500 µg q12h) was compared to the sole administration of fluticasone for five months in a randomized blind trial where the lung function, airway inflammation and bronchial remodeling (histomorphometry of central and peripheral airways and endobronchial ultrasound) of horses with severe neutrophilic asthma were assessed. Although the proportional reduction of airway neutrophilia was significantly larger in the group receiving azithromycin, the lung function and the peripheral and central airway smooth muscle mass decreased similarly in both groups. Despite a better control of airway neutrophilia, azithromycin did not potentiate the other clinical effects of fluticasone.
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Affiliation(s)
- Sophie Mainguy-Seers
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Roxane Boivin
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada.,Laboratoire de Sciences Judiciaires Et de Médecine Légale, Ministère de La Sécurité Publique, Montreal, QC, H2K 3S7, Canada
| | - Sheila Pourali Dogaheh
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Francis Beaudry
- Department of Veterinary Biomedical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Pierre Hélie
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Alvaro G Bonilla
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - James G Martin
- Meakins Christie Laboratories, McGill University, McGill University Health Center Research Institute, Montreal, QC, H4A 3J1, Canada
| | - Jean-Pierre Lavoie
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, J2S 2M2, Canada.
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2
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Donovan GM, Wang KCW, Shamsuddin D, Mann TS, Henry PJ, Larcombe AN, Noble PB. Pharmacological ablation of the airway smooth muscle layer-Mathematical predictions of functional improvement in asthma. Physiol Rep 2021; 8:e14451. [PMID: 32533641 PMCID: PMC7292900 DOI: 10.14814/phy2.14451] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/20/2020] [Accepted: 04/25/2020] [Indexed: 12/16/2022] Open
Abstract
Airway smooth muscle (ASM) plays a major role in acute airway narrowing and reducing ASM thickness is expected to attenuate airway hyper‐responsiveness and disease burden. There are two therapeutic approaches to reduce ASM thickness: (a) a direct approach, targeting specific airways, best exemplified by bronchial thermoplasty (BT), which delivers radiofrequency energy to the airway via bronchoscope; and (b) a pharmacological approach, targeting airways more broadly. An example of the less well‐established pharmacological approach is the calcium‐channel blocker gallopamil which in a clinical trial effectively reduced ASM thickness; other agents may act similarly. In view of established anti‐proliferative properties of the macrolide antibiotic azithromycin, we examined its effects in naive mice and report a reduction in ASM thickness of 29% (p < .01). We further considered the potential functional implications of this finding, if it were to extend to humans, by way of a mathematical model of lung function in asthmatic patients which has previously been used to understand the mechanistic action of BT. Predictions show that pharmacological reduction of ASM in all airways of this magnitude would reduce ventilation heterogeneity in asthma, and produce a therapeutic benefit similar to BT. Moreover there are differences in the expected response depending on disease severity, with the pharmacological approach exceeding the benefits provided by BT in more severe disease. Findings provide further proof of concept that pharmacological targeting of ASM thickness will be beneficial and may be facilitated by azithromycin, revealing a new mode of action of an existing agent in respiratory medicine.
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Affiliation(s)
- Graham M Donovan
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - Kimberley C W Wang
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Respiratory Environmental Health, Telethon Kids Institute, The University of Western Australia, Nedlands, WA, Australia
| | - Danial Shamsuddin
- Respiratory Environmental Health, Telethon Kids Institute, The University of Western Australia, Nedlands, WA, Australia.,School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Tracy S Mann
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Peter J Henry
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Alexander N Larcombe
- Respiratory Environmental Health, Telethon Kids Institute, The University of Western Australia, Nedlands, WA, Australia.,School of Public Health, Curtin University, Bentley, WA, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
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3
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Oliver ME, Hinks TSC. Azithromycin in viral infections. Rev Med Virol 2021; 31:e2163. [PMID: 32969125 PMCID: PMC7536932 DOI: 10.1002/rmv.2163] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 12/18/2022]
Abstract
Azithromycin (AZM) is a synthetic macrolide antibiotic effective against a broad range of bacterial and mycobacterial infections. Due to an additional range of anti-viral and anti-inflammatory properties, it has been given to patients with the coronaviruses SARS-CoV or MERS-CoV. It is now being investigated as a potential candidate treatment for SARS-CoV-2 having been identified as a candidate therapeutic for this virus by both in vitro and in silico drug screens. To date there are no randomised trial data on its use in any novel coronavirus infection, although a large number of trials are currently in progress. In this review, we summarise data from in vitro, murine and human clinical studies on the anti-viral and anti-inflammatory properties of macrolides, particularly AZM. AZM reduces in vitro replication of several classes of viruses including rhinovirus, influenza A, Zika virus, Ebola, enteroviruses and coronaviruses, via several mechanisms. AZM enhances expression of anti-viral pattern recognition receptors and induction of anti-viral type I and III interferon responses. Of relevance to severe coronavirus-19 disease (COVID-19), which is characterised by an over-exuberant innate inflammatory response, AZM also has anti-inflammatory properties including suppression of IL-1beta, IL-2, TNF and GM-CSF. AZM inhibits T cells by inhibiting calcineurin signalling, mammalian target of rapamycin activity and NFκB activation. AZM particularly targets granulocytes where it concentrates markedly in lysosomes, particularly affecting accumulation, adhesion, degranulation and apoptosis of neutrophils. Given its proven safety, affordability and global availability, tempered by significant concerns about antimicrobial stewardship, there is an urgent mandate to perform well-designed and conducted randomised clinical trials.
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Affiliation(s)
| | - Timothy S. C. Hinks
- Nuffield Department of Medicine Experimental Medicine, Respiratory Medicine Unit and National Institute for Health Research (NIHR), Oxford Biomedical Research Centre (BRC)University of OxfordOxfordUK
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4
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Wang Q, Yu MF, Zhang WJ, Liu BB, Zhao QY, Luo X, Xu H, She YS, Zang DA, Qiu JY, Shen J, Peng YB, Zhao P, Xue L, Chen W, Ma LQ, Nie X, Shen C, Chen S, Chen S, Liu Q, Dai J, Qin G, Zheng YM, Wang YX, ZhuGe R, Chen J, Liu QH. Azithromycin inhibits muscarinic 2 receptor-activated and voltage-activated Ca 2+ permeant ion channels and Ca 2+ sensitization, relaxing airway smooth muscle contraction. Clin Exp Pharmacol Physiol 2019; 46:329-336. [PMID: 30609110 DOI: 10.1111/1440-1681.13062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/06/2018] [Accepted: 12/27/2018] [Indexed: 12/20/2022]
Abstract
Azithromycin (AZM) has been used for the treatment of asthma and chronic obstructive pulmonary disease (COPD); however, the effects and underlying mechanisms of AZM remain largely unknown. The effects of AZM on airway smooth muscles (ASMs) and the underlying mechanisms were studied using isometric muscle force measurements, the examination of lung slices, imaging, and patch-clamp techniques. AZM completely inhibited acetylcholine (ACH)-induced precontraction of ASMs in animals (mice, guinea pigs, and rabbits) and humans. Two other macrolide antibiotics, roxithromycin and Klaricid, displayed a decreased inhibitory activity, and the aminoglycoside antibiotics penicillin and streptomycin did not have an inhibitory effect. Precontractions were partially inhibited by nifedipine (selective inhibitor of L-type voltage-dependent Ca2+ channels (LVDCCs)), Pyr3 (selective inhibitor of TRPC3 and/or STIM/Orai channels, which are nonselective cation channels (NSCCs)), and Y-27632 (selective inhibitor of Rho-associated kinase (ROCK)). Moreover, LVDCC- and NSCC-mediated currents were inhibited by AZM, and the latter were suppressed by the muscarinic (M) 2 receptor inhibitor methoctramine. AZM inhibited LVDCC Ca2+ permeant ion channels, M2 receptors, and TRPC3 and/or STIM/Orai, which decreased cytosolic Ca2+ concentrations and led to muscle relaxation. This relaxation was also enhanced by the inhibition of Ca2+ sensitization. Therefore, AZM has potential as a novel and potent bronchodilator. The findings of this study improve the understanding of the effects of AZM on asthma and COPD.
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Affiliation(s)
- Qian Wang
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Meng-Fei Yu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Wen-Jing Zhang
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Bei-Bei Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Qing-Yang Zhao
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Xi Luo
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Hao Xu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Yu-Shan She
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Dun-An Zang
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Jun-Ying Qiu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Jinhua Shen
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Yong-Bo Peng
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Ping Zhao
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Lu Xue
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Weiwei Chen
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Li-Qun Ma
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Xiaowei Nie
- Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Chenyou Shen
- Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Shu Chen
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shanshan Chen
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Quan Liu
- Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jiapei Dai
- Wuhan Institute for Neuroscience and Engineering, South-Central University for Nationalities, Wuhan, China
| | - Gangjian Qin
- Department of Biomedical Engineering, School of Medicine & School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Yun-Min Zheng
- Center for Cardiovascular Sciences, Albany Medical College, Albany, New York
| | - Yong-Xiao Wang
- Center for Cardiovascular Sciences, Albany Medical College, Albany, New York
| | - Ronghua ZhuGe
- Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jingyu Chen
- Jiangsu Key Laboratory of Organ Transplantation, Department of Cardiothoracic Surgery, Lung Transplant Group, Wuxi People's Hospital, Nanjing Medical University, Jiangsu, China
| | - Qing-Hua Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
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5
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Cai Y, Lei Y, Chen J, Cao L, Yang X, Zhang K, Cao Y. Erythromycin relaxes BALB/c mouse airway smooth muscle. Life Sci 2019; 221:135-142. [PMID: 30731142 DOI: 10.1016/j.lfs.2019.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/20/2019] [Accepted: 02/03/2019] [Indexed: 01/19/2023]
Abstract
AIMS Bitter taste receptor (TAS2R) agonists have bronchodilatory potentials. Erythromycin is a ligand of TAS2R10, but its relaxant profile is unknown. This study was performed to understand the relaxant effects of erythromycin and its potential mechanism. MAIN METHODS Airway resistance was tested by the whole body plethysmography in the ovalbumin-aluminum hydroxide induced asthma model mice. Tracheal ring segment myography was used to investigate the isometric tension of the smooth muscle. The cyclic adenosine monophosphate (cAMP) concentration was measured by enzyme immunoassay kit. Changes in the calcium influx in airway smooth muscle cells (ASMCs) were surveyed using a real-time confocal microscopy. KEY FINDINGS Erythromycin significantly relieved airway hyperreactivity in asthma model mice. Erythromycin relaxed mouse tracheal segments precontracted with carbachol, KCl, 5-hydroxytryptamine and U46619, and further dilated the tracheal rings relaxed by isoprenaline or atropine. Epithelium removal, indomethacin or NS-398 partially reduced the relaxation. U73122, 2-APB, iberiotoxin or ouabain did not change the concentration-relaxation curves of erythromycin on tracheal segments. Erythromycin didn't elevate cAMP level. CaCl2-induced contraction in the K+-rich solution was impaired by erythromycin in the Ca2+-free solution. The intercellular Ca2+ level in the ASMCs was decreased by erythromycin, which was partly inhibited by Bay K8644 but not gallein. SIGNIFICANCE Erythromycin had marked bronchodilatory effect. The relaxation might be related to the L-type voltage-dependent calcium channel, but not the gustducin-associated βγ/phospholipase-Cβ/inositol 1,4,5-tri-phosphate receptor/large conductance Ca2+-activated K+ channel pathway or a cAMP-dependent way.
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Affiliation(s)
- Yan Cai
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China; Department of Pharmacy, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China
| | - Ying Lei
- Department of Pharmacy, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China
| | - Jingguo Chen
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Lei Cao
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| | - Xudong Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Kanghuai Zhang
- Department of Pharmacy, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China
| | - Yongxiao Cao
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
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6
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Azithromycin use in patients with cystic fibrosis. Eur J Clin Microbiol Infect Dis 2015; 34:1071-9. [DOI: 10.1007/s10096-015-2347-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 02/01/2015] [Indexed: 12/14/2022]
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Parnham MJ, Erakovic Haber V, Giamarellos-Bourboulis EJ, Perletti G, Verleden GM, Vos R. Azithromycin: mechanisms of action and their relevance for clinical applications. Pharmacol Ther 2014; 143:225-45. [PMID: 24631273 DOI: 10.1016/j.pharmthera.2014.03.003] [Citation(s) in RCA: 371] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 03/04/2014] [Indexed: 01/02/2023]
Abstract
Azithromycin is a macrolide antibiotic which inhibits bacterial protein synthesis, quorum-sensing and reduces the formation of biofilm. Accumulating effectively in cells, particularly phagocytes, it is delivered in high concentrations to sites of infection, as reflected in rapid plasma clearance and extensive tissue distribution. Azithromycin is indicated for respiratory, urogenital, dermal and other bacterial infections, and exerts immunomodulatory effects in chronic inflammatory disorders, including diffuse panbronchiolitis, post-transplant bronchiolitis and rosacea. Modulation of host responses facilitates its long-term therapeutic benefit in cystic fibrosis, non-cystic fibrosis bronchiectasis, exacerbations of chronic obstructive pulmonary disease (COPD) and non-eosinophilic asthma. Initial, stimulatory effects of azithromycin on immune and epithelial cells, involving interactions with phospholipids and Erk1/2, are followed by later modulation of transcription factors AP-1, NFκB, inflammatory cytokine and mucin release. Delayed inhibitory effects on cell function and high lysosomal accumulation accompany disruption of protein and intracellular lipid transport, regulation of surface receptor expression, of macrophage phenotype and autophagy. These later changes underlie many immunomodulatory effects of azithromycin, contributing to resolution of acute infections and reduction of exacerbations in chronic airway diseases. A sub-group of post-transplant bronchiolitis patients appears to be sensitive to azithromycin, as may be patients with severe sepsis. Other promising indications include chronic prostatitis and periodontitis, but weak activity in malaria is unlikely to prove crucial. Long-term administration of azithromycin must be balanced against the potential for increased bacterial resistance. Azithromycin has a very good record of safety, but recent reports indicate rare cases of cardiac torsades des pointes in patients at risk.
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Affiliation(s)
- Michael J Parnham
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Frankfurt am Main, Germany; Institute of Pharmacology for Life Scientists, Goethe University Frankfurt, Frankfurt am Main, Germany; Institute of Clinical Pharmacology, Goethe University Frankfurt, Frankfurt am Main, Germany.
| | | | - Evangelos J Giamarellos-Bourboulis
- 4th Department of Internal Medicine, University of Athens, Medical School, Athens, Greece; Integrated Research and Treatment Center, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
| | - Gianpaolo Perletti
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto A., Varese, Italy; Department of Basic Medical Sciences, Ghent University, Ghent, Belgium.
| | - Geert M Verleden
- Respiratory Division, Lung Transplantation Unit, University Hospitals Leuven and Department of Clinical and Experimental Medicine, KU Leuven, Belgium.
| | - Robin Vos
- Respiratory Division, Lung Transplantation Unit, University Hospitals Leuven and Department of Clinical and Experimental Medicine, KU Leuven, Belgium.
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8
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Zhang CH, Lifshitz LM, Uy KF, Ikebe M, Fogarty KE, ZhuGe R. The cellular and molecular basis of bitter tastant-induced bronchodilation. PLoS Biol 2013; 11:e1001501. [PMID: 23472053 PMCID: PMC3589262 DOI: 10.1371/journal.pbio.1001501] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/24/2013] [Indexed: 01/13/2023] Open
Abstract
Bitter tastants can activate bitter taste receptors on constricted smooth muscle cells to inhibit L-type calcium channels and induce bronchodilation. Bronchodilators are a standard medicine for treating airway obstructive diseases, and β2 adrenergic receptor agonists have been the most commonly used bronchodilators since their discovery. Strikingly, activation of G-protein-coupled bitter taste receptors (TAS2Rs) in airway smooth muscle (ASM) causes a stronger bronchodilation in vitro and in vivo than β2 agonists, implying that new and better bronchodilators could be developed. A critical step towards realizing this potential is to understand the mechanisms underlying this bronchodilation, which remain ill-defined. An influential hypothesis argues that bitter tastants generate localized Ca2+ signals, as revealed in cultured ASM cells, to activate large-conductance Ca2+-activated K+ channels, which in turn hyperpolarize the membrane, leading to relaxation. Here we report that in mouse primary ASM cells bitter tastants neither evoke localized Ca2+ events nor alter spontaneous local Ca2+ transients. Interestingly, they increase global intracellular [Ca2+]i, although to a much lower level than bronchoconstrictors. We show that these Ca2+ changes in cells at rest are mediated via activation of the canonical bitter taste signaling cascade (i.e., TAS2R-gustducin-phospholipase Cβ [PLCβ]- inositol 1,4,5-triphosphate receptor [IP3R]), and are not sufficient to impact airway contractility. But activation of TAS2Rs fully reverses the increase in [Ca2+]i induced by bronchoconstrictors, and this lowering of the [Ca2+]i is necessary for bitter tastant-induced ASM cell relaxation. We further show that bitter tastants inhibit L-type voltage-dependent Ca2+ channels (VDCCs), resulting in reversal in [Ca2+]i, and this inhibition can be prevented by pertussis toxin and G-protein βγ subunit inhibitors, but not by the blockers of PLCβ and IP3R. Together, we suggest that TAS2R stimulation activates two opposing Ca2+ signaling pathways via Gβγ to increase [Ca2+]i at rest while blocking activated L-type VDCCs to induce bronchodilation of contracted ASM. We propose that the large decrease in [Ca2+]i caused by effective tastant bronchodilators provides an efficient cell-based screening method for identifying potent dilators from among the many thousands of available bitter tastants. Bitter taste receptors (TAS2Rs), a G-protein-coupled receptor family long thought to be solely expressed in taste buds on the tongue, have recently been detected in airways. Bitter substances can activate TAS2Rs in airway smooth muscle to cause greater bronchodilation than β2 adrenergic receptor agonists, the most commonly used bronchodilators. However, the mechanisms underlying this bronchodilation remain elusive. Here we show that, in resting primary airway smooth muscle cells, bitter tastants activate a TAS2R-dependent signaling pathway that results in an increase in intracellular calcium levels, albeit to a level much lower than that produced by bronchoconstrictors. In bronchoconstricted cells, however, bitter tastants reverse the bronchoconstrictor-induced increase in calcium levels, which leads to the relaxation of smooth muscle cells. We find that this reversal is due to inhibition of L-type calcium channels. Our results suggest that under normal conditions, bitter tastants can activate TAS2Rs to modestly increase calcium levels, but that when smooth muscle cells are constricted, they can block L-type calcium channels to induce bronchodilation. We postulate that this novel mechanism could operate in other extraoral cells expressing TAS2Rs.
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Affiliation(s)
- Cheng-Hai Zhang
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Lawrence M. Lifshitz
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Karl F. Uy
- Department of Surgery, Division of Thoracic Surgery, University of Massachusetts Memorial Medical Center, Worcester, Massachusetts, United States of America
| | - Mitsuo Ikebe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Kevin E. Fogarty
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ronghua ZhuGe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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9
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Anti-inflammatory and immunomodulatory properties of azithromycin involved in treatment and prevention of chronic lung allograft rejection. Transplantation 2012; 94:101-9. [PMID: 22461039 DOI: 10.1097/tp.0b013e31824db9da] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Chronic lung allograft rejection is the single most important cause of death in lung transplant recipients after the first postoperative year, resulting in a 5-year survival rate of approximately 50%, which is far behind that of other solid organ transplantations. Spirometry is routinely used as a clinical marker for assessing pulmonary allograft function and diagnosing chronic lung allograft rejection after lung transplantation (LTx). As such, a progressive obstructive decline in pulmonary allograft function (forced expiratory volume in 1 sec [FEV1]) in absence of all other causes (currently defined as bronchiolitis obliterans syndrome [BOS]) is considered to reflect the evolution of chronic lung allograft rejection. BOS has a 5-year prevalence of approximately 45% and is thought to be the final common endpoint of various alloimmunologic and nonalloimmunologic injuries to the pulmonary allograft, triggering different innate and adaptive immune responses. Most preventive and therapeutic strategies for this complex process have thus far been largely unsuccessful. However, the introduction of the neomacrolide antibiotic azithromycin (AZI) in the field of LTx as of 2003 made it clear that some patients with established BOS might in fact benefit from such therapy due to its various antiinflammatory and immunomodulatory properties, as summarized in this review. Particularly in patients with an increased bronchoalveolar lavage neutrophilia (i.e., 15%-20% or more), AZI treatment could result in an increase in FEV1 of at least 10%. More recently, it has become clear that prophylactic therapy with AZI actually may prevent BOS and improve FEV1 after LTx, most likely through its interactions with the innate immune system. However, one should always be aware of possible adverse effects related to AZI when implementing this drug as prophylactic or long-term treatment. Even so, AZI therapy after LTx can generally be considered as safe.
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Stamatiou R, Boukas K, Paraskeva E, Molyvdas PA, Hatziefthimiou A. Azithromycin reduces the viability of human bronchial smooth muscle cells. J Antibiot (Tokyo) 2010; 63:71-5. [DOI: 10.1038/ja.2009.125] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Oliynyk I, Varelogianni G, Schalling M, Asplund MS, Roomans GM, Johannesson M. Azithromycin increases chloride efflux from cystic fibrosis airway epithelial cells. Exp Lung Res 2009; 35:210-21. [PMID: 19337904 DOI: 10.1080/01902140802534967] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
It was investigated whether azithromycin (AZM) stimulates chloride (Cl-) efflux from cystic fibrosis (CF) and non-CF airway epithelial cells, possibly secondary to up-regulation of the multidrug resistance protein (MDR). CF and non-CF human airway epithelial cell lines (CFBE and 16HBE) were treated with 0.4, 4, and 40 microg/mL AZM for 4 days. Cl- efflux was explored in the presence or absence of specific inhibitors of CFTR and alternative Cl- channels. Six CF patients received AZM (500 mg daily) for 6 months. The percentage of predicted forced vital capacity (FVC%), forced expiratory volume (FEV1%), and the number of acute exacerbations were compared before and after treatment. Nasal biopsies were taken before and after treatment, and mRNA expression of MDR and CFTR was determined by in situ hybridization. A significant dose-dependent increase of Cl- efflux from CFBE cells (but not from 16HBE cells) was observed after AZM treatment. A CFTR inhibitor significantly reduced AZM-stimulated Cl- efflux from CFBE cells. A significant improvement in FEV1%, and fewer exacerbations were observed. AZM treatment did not affect mRNA expression of MDR and CFTR. The stimulation of Cl- efflux could be part of the explanation for the clinical improvement seen among the patients.
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Affiliation(s)
- Igor Oliynyk
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
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Jartti T, Lehtinen P, Vanto T, Vuorinen T, Hiekkanen H, Hartiala J, Mäkelä MJ, Ruuskanen O. Atopic characteristics of wheezing children and responses to prednisolone. Pediatr Pulmonol 2007; 42:1125-33. [PMID: 17968992 PMCID: PMC7167645 DOI: 10.1002/ppul.20706] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 08/15/2007] [Accepted: 08/15/2007] [Indexed: 02/02/2023]
Abstract
We wanted to test the hypothesis that the efficacy of systemic corticosteroid is associated with atopic characteristics in wheezing children. A randomized controlled trial comparing oral prednisolone (2 mg/kg/day in 3 divided doses for 3 days) with placebo in hospitalized wheezing children (n = 266, median 1.6 years, range 3 months to 15.2 years) was conducted. In this post-hoc analysis, we assessed the link between the efficacy of prednisolone and several atopic characteristics, such as atopy, aeroallergen sensitization, total IgE level, number of sensitizations, eczema, atopic eczema, blood or nasal eosinophils, exhaled nitric oxide, positive modified asthma predictive index/asthma, inhaled corticosteroid medication and parental asthma/allergy. Virology was studied comprehensively. Our primary endpoint was the time until ready for discharge, and the most important secondary endpoint was the occurrence of relapses during the following 2 months. For statistics, we used interaction analyses in uni- and multivariate regression models. Overall, prednisolone did not decrease any of our predefined clinical endpoints. Neither was the efficacy of prednisolone associated with atopy. However, prednisolone significantly decreased the time until ready for discharge in children with positive modified asthma predictive index/asthma, inhaled corticosteroids, or rhinovirus infection and/or in children without azithromycin treatment. Prednisolone significantly decreased relapses in children with eczema, nasal eosinophilia and rhinovirus infection. The multiple clinical, inflammatory and viral markers associating with the efficacy of prednisolone should be confirmed in prospective trials. It is important that corticosteroid intervention trials have strict design for these potentially confounding factors.
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Affiliation(s)
- Tuomas Jartti
- Department of Pediatrics, Turku University Hospital, Turku, Finland.
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