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Borkar NA, Thompson MA, Bartman CM, Sathish V, Prakash YS, Pabelick CM. Nicotine affects mitochondrial structure and function in human airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2023; 325:L803-L818. [PMID: 37933473 PMCID: PMC11068407 DOI: 10.1152/ajplung.00158.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/26/2023] [Accepted: 10/24/2023] [Indexed: 11/08/2023] Open
Abstract
Exposure to cigarette smoke and e-cigarettes, with nicotine as the active constituent, contributes to increased health risks associated with asthma. Nicotine exerts its functional activity via nicotinic acetylcholine receptors (nAChRs), and the alpha7 subtype (α7nAChR) has recently been shown to adversely affect airway dynamics. The mechanisms of α7nAChR action in airways, particularly in the context of airway smooth muscle (ASM), a key cell type in asthma, are still under investigation. Mitochondria have garnered increasing interest for their role in regulating airway tone and adaptations to cellular stress. Here mitochondrial dynamics such as fusion versus fission, and mitochondrial Ca2+ ([Ca2+]m), play an important role in mitochondrial homeostasis. There is currently no information on effects and mechanisms by which nicotine regulates mitochondrial structure and function in ASM in the context of asthma. We hypothesized that nicotine disrupts mitochondrial morphology, fission-fusion balance, and [Ca2+]m regulation, with altered mitochondrial respiration and bioenergetics in the context of asthmatic ASM. Using human ASM (hASM) cells from nonasthmatics, asthmatics, and smokers, we examined the effects of nicotine on mitochondrial dynamics and [Ca2+]m. Fluorescence [Ca2+]m imaging of hASM cells with rhod-2 showed robust responses to 10 μM nicotine, particularly in asthmatics and smokers. In both asthmatics and smokers, nicotine increased the expression of fission proteins while decreasing fusion proteins. Seahorse analysis showed blunted oxidative phosphorylation parameters in response to nicotine in these groups. α7nAChR siRNA blunted nicotine effects, rescuing [Ca2+]m, changes in mitochondrial structural proteins, and mitochondrial dysfunction. These data highlight mitochondria as a target of nicotine effects on ASM, where mitochondrial disruption and impaired buffering could permit downstream effects of nicotine in the context of asthma.NEW & NOTEWORTHY Asthma is a major healthcare burden, which is further exacerbated by smoking. Recognizing the smoking risk of asthma, understanding the effects of nicotine on asthmatic airways becomes critical. Surprisingly, the mechanisms of nicotine action, even in normal and especially asthmatic airways, are understudied. Accordingly, the goal of this research is to investigate how nicotine influences asthmatic airways in terms of mitochondrial structure and function, via the a7nAChR.
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Affiliation(s)
- Niyati A Borkar
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Michael A Thompson
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Colleen M Bartman
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota, United States
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
| | - Christina M Pabelick
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
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Borkar NA, Roos B, Prakash YS, Sathish V, Pabelick CM. Nicotinic α7 acetylcholine receptor (α7nAChR) in human airway smooth muscle. Arch Biochem Biophys 2021; 706:108897. [PMID: 34004182 DOI: 10.1016/j.abb.2021.108897] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 12/31/2022]
Abstract
Diseases such as asthma are exacerbated by inflammation, cigarette smoke and even nicotine delivery devices such as e-cigarettes. However, there is currently little information on how nicotine affects airways, particularly in humans, and changes in the context of inflammation or asthma. Here, a longstanding assumption is that airway smooth muscle (ASM) that is key to bronchoconstriction has muscarinic receptors while nicotinic receptors (nAChRs) are only on airway neurons. In this study, we tested the hypothesis that human ASM expresses α7nAChR and explored its profile in inflammation and asthma using ASM of non-asthmatics vs. mild-moderate asthmatics. mRNA and western analysis showed the α7 subunit is most expressed in ASM cells and further increased in asthmatics and smokers, or by exposure to nicotine, cigarette smoke or pro-inflammatory cytokines TNFα and IL-13. In these effects, signaling pathways relevant to asthma such as NFκB, AP-1 and CREB are involved. These novel data demonstrate the expression of α7nAChR in human ASM and suggest their potential role in asthma pathophysiology in the context of nicotine exposure.
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Affiliation(s)
- Niyati A Borkar
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, USA
| | - Benjamin Roos
- Department of Anesthesiology and Perioperative Medicine, USA
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, USA
| | - Christina M Pabelick
- Department of Anesthesiology and Perioperative Medicine, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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Urinary Leukotriene E4and 2,3-Dinor Thromboxane B2Are Biomarkers of Potential Harm in Short-Term Tobacco Switching Studies. Cancer Epidemiol Biomarkers Prev 2019; 28:2095-2105. [DOI: 10.1158/1055-9965.epi-19-0342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 08/22/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022] Open
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Hussain M, Xu C, Yao M, Zhang Q, Wu J, Wu X, Lu M, Tang L, Wu F, Wu X. CRTH2 antagonist, CT‑133, effectively alleviates cigarette smoke-induced acute lung injury. Life Sci 2019; 216:156-167. [PMID: 30468833 DOI: 10.1016/j.lfs.2018.11.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 01/01/2023]
Abstract
AIMS Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), characterized by overwhelming lung inflammation, are associated with high mortality. Cigarette smoke (CS) is one of the major causes of ALI/ARDS. Since high expression of prostaglandin (PG) D2 has been observed in CS-induced lung injury. Currently, no effective pharmacological therapies are available to treat ALI, and supportive therapies remain the mainstay of treatment. Therefore, we investigated the protective effect of CT‑133, a newly discovered selective CRTH2 antagonist, on CS-induced ALI in vivo and in vitro. MAIN METHODS CT‑133 (10 and 30 mg/kg), dexamethasone (1 mg/kg) and normal saline were intratracheally administrated 1 hr prior to whole-body CS-exposure for seven consecutive days to study the key characteristics of ALI. Subsequently, CSE (4%)- and PGD2-stimulated RAW 264.7 macrophages were used to evaluate the protective effect of CT‑133. KEY FINDINGS CT‑133 remarkably attenuated infiltration of inflammatory cells, neutrophils, and macrophages in the BALF, albumin contents, expression of IL‑1β, IL‑6, TNF‑α and KC, lung myeloperoxidase (MPO) activity and lung histopathological alterations caused by CS exposure in mice. Moreover, CT‑133 not only reversed the uncontrolled secretion of IL‑1β, IL-6, TNF‑α and KC from CSE- and PGD2-stimulated RAW 264.7 macrophages but also augmented IL-10 production in both in vivo and in vitro studies. Additionally, CT‑133 alleviated in vitro neutrophil migration chemoattracted by PGD2. SIGNIFICANCE Our results provide the first evidence that targeting CRTH2 could be a new potential therapeutic option to treat CS-induced ALI.
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Affiliation(s)
- Musaddique Hussain
- Department of Pharmacology, Zhejiang University, School of Medicine, Hangzhou City 310058, China
| | - Chengyun Xu
- Department of Pharmacology, Zhejiang University, School of Medicine, Hangzhou City 310058, China
| | - Minli Yao
- Department of Pharmacology, Zhejiang University, School of Medicine, Hangzhou City 310058, China
| | - Qin Zhang
- Department of Pharmacology, Zhejiang University, School of Medicine, Hangzhou City 310058, China
| | - Junsong Wu
- Department of Critical Care Medicine and Orthopedics, The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou City 310009, China
| | - Xiling Wu
- Department of Respiratory Medicine, the Affiliated Children Hospital, Zhejiang University School of Medicine, Hangzhou City 310052, China
| | - Meiping Lu
- Department of Respiratory Medicine, the Affiliated Children Hospital, Zhejiang University School of Medicine, Hangzhou City 310052, China
| | - Lanfang Tang
- Department of Respiratory Medicine, the Affiliated Children Hospital, Zhejiang University School of Medicine, Hangzhou City 310052, China
| | - Fugen Wu
- Department of Pediatrics, The First People's Hospital of Wenling City, Wenling City 317500, China.
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University, School of Medicine, Hangzhou City 310058, China.
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Fiori NS, Fassa AG, Faria NMX, Meucci RD, Miranda VI, Christiani DC. Wheezing in tobacco farm workers in southern Brazil. Am J Ind Med 2015; 58:1217-28. [PMID: 26471879 PMCID: PMC4732558 DOI: 10.1002/ajim.22447] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND Tobacco workers are exposed to several respiratory occupational sensitizers. METHODS A representative cross-sectional study was carried out on 2469 tobacco family farming growers. Gender-stratified multivariate analyses evaluated the association between wheezing and socio-demographic, behavioral, and occupational variables. RESULTS Wheezing prevalence was 11.0% with no difference between genders. Among men, age, smoking, strenuous work, pesticide use, contact with vegetable dust and dried tobacco dust, lifting sticks with tobacco leaves to the curing barns, and green tobacco sickness (GTS) were risk factors for wheezing. Among women, family history of asthma, tying hands of tobacco, strenuous work, contact with chemical disinfectants, and GTS were positively associated with wheezing. Harvesting lower tobacco leaves was a protective factor for the outcome in both genders. CONCLUSIONS Pesticides, dusts exposure, and GTS were risk factors for wheezing. The synergic effect of these factors needs to be better evaluated to improve prevention.
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Affiliation(s)
- Nadia Spada Fiori
- Social Medicine Department, Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil
- Takemi Program in International Health, Department of Global Health and Population, Harvard School of Public Health, Boston, Massachusetts
| | - Anaclaudia Gastal Fassa
- Social Medicine Department, Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil
| | | | - Rodrigo Dalke Meucci
- Social Medicine Department, Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil
| | - Vanessa Iribarrem Miranda
- Social Medicine Department, Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil
| | - David C. Christiani
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts
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Abstract
Sensory nerves innervating the lung and airways play an important role in regulating various cardiopulmonary functions and maintaining homeostasis under both healthy and disease conditions. Their activities conducted by both vagal and sympathetic afferents are also responsible for eliciting important defense reflexes that protect the lung and body from potential health-hazardous effects of airborne particulates and chemical irritants. This article reviews the morphology, transduction properties, reflex functions, and respiratory sensations of these receptors, focusing primarily on recent findings derived from using new technologies such as neural immunochemistry, isolated airway-nerve preparation, cultured airway neurons, patch-clamp electrophysiology, transgenic mice, and other cellular and molecular approaches. Studies of the signal transduction of mechanosensitive afferents have revealed a new concept of sensory unit and cellular mechanism of activation, and identified additional types of sensory receptors in the lung. Chemosensitive properties of these lung afferents are further characterized by the expression of specific ligand-gated ion channels on nerve terminals, ganglion origin, and responses to the action of various inflammatory cells, mediators, and cytokines during acute and chronic airway inflammation and injuries. Increasing interest and extensive investigations have been focused on uncovering the mechanisms underlying hypersensitivity of these airway afferents, and their role in the manifestation of various symptoms under pathophysiological conditions. Several important and challenging questions regarding these sensory nerves are discussed. Searching for these answers will be a critical step in developing the translational research and effective treatments of airway diseases.
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Affiliation(s)
- Lu-Yuan Lee
- Department of Physiology, University of Kentucky, Lexington, Kentucky
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7
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Chávez J, Vargas MH, Rebollar-Ayala DC, Díaz-Hernández V, Cruz-Valderrama JE, Flores-Soto E, Flores-García M, Jiménez-Vargas NN, Barajas-López C, Montaño LM. Inhibition of extracellular nucleotides hydrolysis intensifies the allergic bronchospasm. A novel protective role of ectonucleotidases. Allergy 2013; 68:462-71. [PMID: 23414231 DOI: 10.1111/all.12113] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2012] [Indexed: 01/31/2023]
Abstract
BACKGROUND Nucleotides released to the extracellular space stimulate purinergic receptors, and their effects are modulated by ectonucleotidases. The role of ATP in the allergic bronchospasm has been scantly studied. METHODS We used several techniques (plethysmography, organ baths, confocal microscopy, RT-PCR, ATP measurement) to explore the role of nucleotides and ectonucleotidases in the allergic bronchospasm in guinea pigs. RESULTS While allergenic challenge with a low-dose ovalbumin (OVA) only produced a small bronchospasm (~2-fold the basal lung resistance), previous inhibition of ectonucleotidases by ARL-67156 greatly intensified this response (~11-fold the basal lung resistance, with 44% mortality). Bronchoalveolar lavage fluid obtained during this bronchospasm contained increased ATP concentration. This potentiation was abolished by antagonism of purinergic receptors (suramin+RB2) or TXA2 receptor (SQ29548), or by intratracheal apyrase. In tracheal rings and lung parenchyma strips, OVA caused a concentration-dependent contraction. Suramin+RB2 or levamisole produced a significant rightward displacement of this response, and ARL-67156 did not modify it. Platelets stimulated with OVA released ATP. Confocal images of nonsensitized tracheas showed slight fluorescence for P2Y6 receptors in epithelium and none for P2Y4 . Sensitized animals showed strong fluorescence to both receptors and to alkaline phosphatase in the airway epithelium. This correlated with a large increment in mRNA for P2Y4 and P2Y6 receptors in sensitized animals. CONCLUSIONS Nucleotides greatly potentiate the allergic bronchospasm when ectonucleotidases activity is diminished, and this effect is probably favored by the upregulation of P2Y4 and P2Y6 receptors in airway epithelium during sensitization. These results prompt for further research on these mechanisms in human asthma.
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Affiliation(s)
- J. Chávez
- Departamento de Investigación en Hiperreactividad Bronquial; Instituto Nacional de Enfermedades Respiratorias; México; DF; México
| | - M. H. Vargas
- Departamento de Investigación en Hiperreactividad Bronquial; Instituto Nacional de Enfermedades Respiratorias; México; DF; México
| | - D. C. Rebollar-Ayala
- Departamento de Farmacología; Facultad de Medicina; Universidad Nacional Autónoma de México; México; DF; México
| | - V. Díaz-Hernández
- Departamento de Embriología; Facultad de Medicina; Universidad Nacional Autónoma de México; México; DF; México
| | - J. E. Cruz-Valderrama
- Departamento de Farmacología; Facultad de Medicina; Universidad Nacional Autónoma de México; México; DF; México
| | - E. Flores-Soto
- Departamento de Farmacología; Facultad de Medicina; Universidad Nacional Autónoma de México; México; DF; México
| | - M. Flores-García
- Departamento de Biología Molecular; Instituto Nacional de Cardiología; México; DF; México
| | - N. N. Jiménez-Vargas
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí; S.L.P.; México
| | - C. Barajas-López
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí; S.L.P.; México
| | - L. M. Montaño
- Departamento de Farmacología; Facultad de Medicina; Universidad Nacional Autónoma de México; México; DF; México
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Huang RY, Chen GG. Cigarette smoking, cyclooxygenase-2 pathway and cancer. Biochim Biophys Acta Rev Cancer 2010; 1815:158-69. [PMID: 21147199 DOI: 10.1016/j.bbcan.2010.11.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/23/2010] [Accepted: 11/29/2010] [Indexed: 12/16/2022]
Abstract
Cigarette smoking is a major cause of mortality and morbidity worldwide. Cyclooxygenase (COX) and its derived prostanoids, mainly including prostaglandin E2 (PGE2), thromboxane A2 (TxA2) and prostacyclin (PGI2), have well-known roles in cardiovascular disease and cancer, both of which are associated with cigarette smoking. This article is focused on the role of COX-2 pathway in smoke-related pathologies and cancer. Cigarette smoke exposure can induce COX-2 expression and activity, increase PGE2 and TxA2 release, and lead to an imbalance in PGI2 and TxA2 production in favor of the latter. It exerts pro-inflammatory effects in a PGE2-dependent manner, which contributes to carcinogenesis and tumor progression. TxA2 mediates other diverse biologic effects of cigarette smoking, such as platelet activation, cell contraction and angiogenesis, which may facilitate tumor growth and metastasis in smokers. Among cigarette smoke components, nicotine and its derived nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are the most potent carcinogens. COX-2 and PGE2 have been shown to play a pivotal role in many cancers associated with cigarette smoking, including cancers of lung, gastric and bladder, while the information for the role of TxA2 and PGI2 in smoke-associated cancers is limited. Recent findings from our group have revealed how NNK influences the TxA2 to promote the tumor growth. Better understanding in the above areas may help to generate new therapeutic protocols or to optimize the existing treatment strategy.
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Affiliation(s)
- Run-Yue Huang
- Department of Surgery, The Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Stebbins KJ, Broadhead AR, Baccei CS, Scott JM, Truong YP, Coate H, Stock NS, Santini AM, Fagan P, Prodanovich P, Bain G, Stearns BA, King CD, Hutchinson JH, Prasit P, Evans JF, Lorrain DS. Pharmacological Blockade of the DP2 Receptor Inhibits Cigarette Smoke-Induced Inflammation, Mucus Cell Metaplasia, and Epithelial Hyperplasia in the Mouse Lung. J Pharmacol Exp Ther 2009; 332:764-75. [DOI: 10.1124/jpet.109.161919] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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10
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Zhang W, Zhang Y, Edvinsson L, Xu CB. Up-regulation of thromboxane A2 receptor expression by lipid soluble smoking particles through post-transcriptional mechanisms. Atherosclerosis 2008; 196:608-16. [PMID: 17706224 DOI: 10.1016/j.atherosclerosis.2007.06.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 06/23/2007] [Accepted: 06/25/2007] [Indexed: 12/12/2022]
Abstract
Atherosclerosis is a key factor in vascular disease, and cigarette smoking is a well-known risk factor that may induce an inflammatory response and enhance plaque formation in arteries. Thromboxane (Tx) is one key inflammatory mediator involved in the pathogenesis of cardiovascular disease. The present study was designed to test if lipid soluble smoking particles (DSP) enhance TxA(2) receptor (TP) expression in rat mesenteric arteries, and if intracellular mitogen-activated protein kinase (MAPK) pathways play a role. Organ culture of rat mesenteric arteries in the presence of DSP (0.2 microl/ml for 24h) resulted in markedly elevated contractile responses to the Tx analog U46619, compared with the control DMSO. There was no increase in TP receptor mRNA expression, while the protein expression was significantly enhanced. This up-regulation was not affected by a general transcriptional inhibitor actinomycin D, but was almost completely abolished by cycloheximide, a general translational inhibitor. Dexamethasone, a glucocorticoid, manifested a potent inhibitory effect as well. These results suggest that the up-regulation of TP receptor occurs via post-transcriptional events, and mainly translation. This is supported by experiments with specific inhibitors for c-Jun-NH(2)-terminal kinase (SP600125), extracellular signal-regulated kinase 1 and 2 (PD98059 and U0126) and p38 (SB203580) that had no inhibitory effect on the up-regulation of TP receptors. Collectively, the results show that MAPK pathways are not involved in TP receptor up-regulation. Study on TP receptor mRNA stability showed that during organ culture, the TP receptor mRNA was stable in both DMSO and DSP group, but the latter elicited a tendency to stabilize the TP receptor mRNA at higher level. Thus, post-transcriptional mechanisms are responsible for the up-regulation of TP receptor by DSP, in which enhanced translation is the major cause of the elevated protein expression and the enhanced contraction.
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Affiliation(s)
- Wei Zhang
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden
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Xu J, Yang W, Zhang G, Gu Q, Lee LY. Calcium transient evoked by nicotine in isolated rat vagal pulmonary sensory neurons. Am J Physiol Lung Cell Mol Physiol 2007; 292:L54-61. [PMID: 16920888 DOI: 10.1152/ajplung.00182.2006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
It has been shown that inhaled cigarette smoke activates vagal pulmonary C fibers and rapidly adapting receptors (RARs) in the airways and that nicotine contained in the smoke is primarily responsible. This study was carried out to determine whether nicotine alone can activate pulmonary sensory neurons isolated from rat vagal ganglia; the response of these neurons was determined by fura-2-based ratiometric Ca2+imaging. The results showed: 1) Nicotine (10−4M, 20 s) evoked a transient increase in intracellular Ca2+concentration ([Ca2+]i) in 175 of the 522 neurons tested (Δ[Ca2+]i= 142.2 ± 12.3 nM); the response was reproducible, with a small reduction in peak amplitude in the same neurons when the challenge was repeated 20 min later. 2) A majority (59.7%) of these nicotine-sensitive neurons were also activated by capsaicin (10−7M). 3) 1,1-Dimethyl-4-phenylpiperazinium iodide (DMPP; 10−4M, 20 s), a selective agonist of the neuronal nicotinic acetylcholine receptors (NnAChRs), evoked a pattern of response similar to that of nicotine. 4) The responses to nicotine and DMPP were either totally abrogated or markedly attenuated by hexamethonium (10−4M). 5) In anesthetized rats, right atrial bolus injection of nicotine (75–200 μg/kg) evoked an immediate (latency <1–2 s) and intense burst of discharge in 47.8% of the pulmonary C-fiber endings and 28.6% of the RARs tested. In conclusion, nicotine exerts a direct stimulatory effect on vagal pulmonary sensory nerves, and the effect is probably mediated through an activation of the NnAChRs expressed on the membrane of these neurons.
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Affiliation(s)
- Jennings Xu
- Department of Physiology, University of Kentucky Medical Center, Lexington, KY 40536-0298, USA
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12
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Unlu M, Fidan F, Sezer M, Tetik L, Sahin O, Esme H, Koken T, Serteser M. Effects of melatonin on the oxidant/antioxidant status and lung histopathology in rabbits exposed to cigarette smoke. Respirology 2006; 11:422-8. [PMID: 16771911 DOI: 10.1111/j.1440-1843.2006.00865.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES AND BACKGROUND To evaluate the effects of cigarette smoking on the histopathology and the oxidant/antioxidant status of the lungs and to test the potential antioxidant benefits of melatonin on these induced changes. METHODOLOGY Rabbits were exposed to cigarette smoke in a glass chamber for 1 h daily for 1 month with or without intraperitoneal melatonin injection. A melatonin control group was given intraperitoneal melatonin only. A control group was exposed to clean air only. At the end of 1 month, animals were sacrificed and lung tissues were examined histopathologically. Blood levels of protein sulphydryls, carbonyls, prostaglandin F2alpha (PGF2alpha), malondialdehyde (MDA), glutathione peroxidase and superoxide dismutase (SOD) were measured. RESULTS Intraparenchymal vascular congestion and thrombosis, intraparenchymal haemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar and bronchial lumen, alveolar destruction, emphysematous changes and bronchoalveolar haemorrhage scores were significantly increased in rabbits exposed to cigarette smoke compared with the control group. Protein sulphydryls and SOD levels were significantly decreased; carbonyls, PGF2alpha and MDA levels were significantly increased in the smoke exposed rabbits. Administration of melatonin to rabbits exposed to cigarette smoke caused a reduction in the bronchoalveolar haemorrhage score and blood carbonyls levels. Other parameters were unaffected by melatonin. CONCLUSION Exposure to cigarette smoke causes severe histopathological changes and negatively affects the oxidant/antioxidant status in the lungs of rabbits. A low daily dose of melatonin has some protective effects on histopathological changes and oxidant/antioxidant status of the lungs in smoke exposed rabbits.
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Affiliation(s)
- Mehmet Unlu
- Afyon Kocatepe University Faculty of Medicine, Department of Pulmonary Medicine, Ayfon, Turkey
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13
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Iida M, Iida H, Fujiwara H, Dohi S. Effects of alcohol infusion on smoking-induced cerebrovascular changes in rat in vivo. Alcohol 2003; 30:175-81. [PMID: 13679111 DOI: 10.1016/j.alcohol.2003.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The combined effects of alcohol and cigarette smoking on the cerebral circulation are unknown. The current study was designed (1) to compare the acute effects on cerebral vessels of cigarette smoking alone with those of alcohol plus cigarette smoking and (2) to clarify the mechanism or mechanisms underlying the cerebrovascular responses. In pentobarbital-anesthetized, mechanically ventilated Sprague-Dawley rats, we measured pial vessel diameters with the use of a cranial window preparation. Rats, pretreated with alcohol (n = 6; 1 g/kg/h, i.v.; 1-h infusion from t = -60 min to t = 0) or with saline (n = 6), were exposed to 60 puffs per minute of mainstream smoke from a 1 mg-nicotine cigarette. Inhalation of smoke caused pial arterioles to constrict at t = 30 s (8.4%) and, subsequently, to dilate (peak at t = 5-10 min; 18.7%). Pretreatment with alcohol caused pial vasodilation (14.0%), and, after inhalation of cigarette smoke, the pial vasodilation occurred earlier (peak at t = 1-5 min; 30.2%) and was larger, without an initial vasoconstriction. The plasma concentration of thromboxane (TX) B2 (a stable metabolite of TXA2) increased after this smoking, and alcohol pretreatment attenuated this increase (protocol as above). Cigarette smoking had a significant biphasic effect on cerebral arteriolar tone. However, alcohol suppressed the initial vasoconstriction, probably, at least in part, by attenuating the smoking-induced TXA2 production.
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Affiliation(s)
- Mami Iida
- 2nd Department of Internal Medicine, Gifu University School of Medicine, Gifu-City, Gifu 500-8705, Japan
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Wu ZX, Zhou D, Chen G, Lee LY. Airway hyperresponsiveness to cigarette smoke in ovalbumin-sensitized guinea pigs. Am J Respir Crit Care Med 2000; 161:73-80. [PMID: 10619800 DOI: 10.1164/ajrccm.161.1.9809121] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
This study was carried out to determine if the bronchoconstrictive effect of cigarette smoke (CS) is enhanced when airway hyperresponsiveness is induced by ovalbumin (Ova) sensitization, and if so, whether an increase in endogenously released tachykinins is involved. The bronchoconstrictive effects of an acute CS inhalation challenge (15 ml; 50% concentration) were compared between guinea pigs sensitized with aerosolized Ova and matching control animals (receiving saline aerosol). In Ova-sensitized animals, there were marked increases in the numbers of eosinophils and neutrophils in the bronchoalveolar lavage fluid (BALF), which was accompanied by an elevated bronchomotor response to acetylcholine (ACh). The baseline lung resistance (RL) and dynamic pulmonary compliance (Cdyn) were not significantly different between the two groups; however, the same CS inhalation challenge evoked a significantly more intense bronchoconstriction in the Ova-sensitized group (control group: DeltaRL = 68 +/- 8%, DeltaCdyn = -26 +/- 6%; Ova group: DeltaRL = 425 +/- 76%; DeltaCdyn = -47 +/- 8%). The levels of substance P-like immunoreactivity (SP-LI) and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) measured in the bronchoalveolar lavage (BAL) collected after CS inhalation challenge were also significantly greater in Ova-sensitized animals than in control animals. Furthermore, pretreatment with SR-48968, a selective antagonist of neurokinin-2 (NK(2)) receptor, inhibited more than 85% of the enhanced bronchomotor responses to CS challenge, but did not significantly reduce the airway hyperresponsiveness to ACh in Ova-sensitized guinea pigs. These results show that Ova sensitization induces airway hyperresponsiveness to inhaled CS, and that the endogenous tachykinins evoked by CS-induced activation of lung C fibers play a primary role in this augmented response.
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Affiliation(s)
- Z X Wu
- Department of Physiology and Division of Allergy and Immunology, University of Kentucky, Lexington, Kentucky 40536-0084, USA
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Lee LY, Hong JL. Involvement of prostanoids in cigarette smoking-induced pathophysiological effects in the lung. Prostaglandins Leukot Essent Fatty Acids 1999; 61:145-55. [PMID: 10582654 DOI: 10.1054/plef.1999.0084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- L Y Lee
- Department of Physiology, University of Kentucky, Lexington 40536, USA.
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Ishikawa T, Sekizawa SI, Sant'Ambrogio FB, Sant'Ambrogio G. Larynx vs. esophagus as reflexogenic sites for acid-induced bronchoconstriction in dogs. J Appl Physiol (1985) 1999; 86:1226-30. [PMID: 10194207 DOI: 10.1152/jappl.1999.86.4.1226] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bronchoconstriction in asthmatic patients is frequently associated with gastroesophageal reflux. However, it is still unclear whether bronchoconstriction originates from the esophagus or from aspiration of the refluxate into the larynx and larger airway. We compared the effect of repeated esophageal and laryngeal instillations of HCl-pepsin (pH 1.0) on tracheal smooth muscle activity in eight anesthetized and artificially ventilated dogs. Saline was used as control. We used pressure in the cuff of an endotracheal tube (Pcuff) as a direct index of smooth muscle activity at the level of the larger airways controlled by vagal efferents. The Pcuff values of the first 60 s after instillations were averaged, and the difference from the baseline values was evaluated. Changes in Pcuff were significantly greater with laryngeal than with esophageal instillations (P = 0.0166). HCl-pepsin instillation into the larynx evoked greater responses than did saline (P = 0.00543), whereas no differences were detected with esophageal instillations. Repeated laryngeal exposure enhanced the responsiveness significantly (P < 0. 001). Our data indicate that the larynx is more important than the esophagus as a reflexogenic site for the elicitation of reflex bronchoconstriction in response to acidic solutions.
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Affiliation(s)
- T Ishikawa
- Department of Physiology and Biophysics, The University of Texas Medical Branch, Galveston, Texas 77555-0641, USA
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Matsumoto K, Aizawa H, Inoue H, Takata S, Shigyo M, Hara N. Role of adrenergic nervous system in cigarette smoke-induced bronchoconstriction in guinea pigs. Eur J Pharmacol 1998; 358:49-54. [PMID: 9809868 DOI: 10.1016/s0014-2999(98)00581-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The goal of this study was to clarify the role of the adrenergic nervous system in bronchoconstriction induced by exposure to cigarette smoke in guinea pigs. Artificially ventilated animals were exposed to 160 puffs of smoke for 8 min. Bronchoconstriction was assessed as a percentage of the baseline total pulmonary resistance (RL). The effects of pretreatment with phentolamine (0.1 mg/kg, i.v.), propranolol (1 mg/kg, i.v.), and/or atropine (1 mg/kg, i.v.) were evaluated. Exposure to cigarette smoke caused significant bronchoconstriction. Phentolamine, an alpha-adrenoceptor antagonist, significantly inhibited cigarette smoke-induced bronchoconstriction, while propranolol, a beta-adrenoceptor antagonist, significantly enhanced it. Combined use of these compounds further enhanced the bronchoconstriction. All of modulations of the bronchoconstriction by adrenoceptor antagonists were completely abolished by pretreatment with atropine. Phentolamine and/or propranolol had no effect on the bronchoconstriction induced by inhaled acetylcholine. Pretreatment with yohimbine (0.5 mg/kg, i.v.), a selective alpha2-adrenoceptor antagonist, showed modulatory effects similar to those of phentolamine on cigarette smoke-induced bronchoconstriction. These results suggest that cigarette smoke-induced bronchoconstriction is regulated by the prejunctional modulation of the cholinergic system via alpha- and beta-adrenoceptors. This mechanism may be modulated by the autoregulation of adrenergic nerves via the alpha2-autoreceptor.
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Affiliation(s)
- K Matsumoto
- Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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Iida M, Iida H, Dohi S, Takenaka M, Fujiwara H. Mechanisms underlying cerebrovascular effects of cigarette smoking in rats in vivo. Stroke 1998; 29:1656-65. [PMID: 9707209 DOI: 10.1161/01.str.29.8.1656] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The effects of acute smoking on cerebral circulation are controversial. This study was designed (1) to clarify any differences between the effects of cigarette smoking and nicotine infusion and between the effects of single- and multiple-cigarette smoking on cerebral vessels and (2) to probe the mechanism(s) underlying the vascular responses. METHODS In pentobarbital-anesthetized, mechanically ventilated Sprague-Dawley rats, pial vessel diameters were measured with the use of a cranial window preparation. We studied the effects of (1) 60 puffs per minute of mainstream cigarette smoke from cigarettes having 2 nicotine levels (0.1 and 1 mg per cigarette), (2) administration of nicotine (0.05 mg per body IV), and (3) repeated smoking (four 1 mg nicotine-containing cigarettes at 30-minute intervals) (n=6 each). RESULTS Inhalation of smoke from a 0.1 or 1 mg nicotine-containing cigarette for 1 minute caused pial arterioles to constrict at 30 seconds (7.2% and 7.3%, respectively) and then to dilate (peak at 5 to 10 minutes; 4.6% and 17.9%, respectively). Nicotine infusion caused pial vasodilation (35.7%) without an initial vasoconstriction. Repeated smoking suppressed the pial vasodilation but not the initial vasoconstriction. The vasodilation induced by a single cigarette was greatly inhibited by pretreatment with mecamylamine or glibenclamide and attenuated by propranolol or Nomega-nitro-L-arginine methyl ester; the initial vasoconstriction was inhibited by seratrodast, a thromboxane A2 receptor antagonist (n=6 in each case). CONCLUSIONS Single-cigarette smoking had a significant biphasic effect on cerebral arteriolar tone. The vasodilation was attenuated by repeated smoking. The vasodilation is most likely an effect of nicotine, at least in part mediated via sympathetic activation, NO production, and K+ channel activation. The vasoconstriction is partially due to thromboxane A2 induced by cigarette smoke.
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Affiliation(s)
- M Iida
- Department of Anesthesiology and Critical Care Medicine, Gifu University School of Medicine, Japan
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Wu ZX, Morton RF, Lee LY. Role of tachykinins in ozone-induced airway hyperresponsiveness to cigarette smoke in guinea pigs. J Appl Physiol (1985) 1997; 83:958-65. [PMID: 9292485 DOI: 10.1152/jappl.1997.83.3.958] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Acute exposure to ozone (O3) induces airway hyperresponsiveness to various inhaled bronchoactive substances. Inhalation of cigarette smoke, a common inhaled irritant in humans, is known to evoke a transient bronchoconstrictive effect. To examine whether O3 increases airway responsiveness to cigarette smoke, effects of smoke inhalation challenge on total pulmonary resistance (RL) and dynamic lung compliance (Cdyn) were compared before and after exposure to O3 (1.5 ppm, 1 h) in anesthetized guinea pigs. Before O3 exposure, inhalation of two breaths of cigarette smoke (7 ml) at a low concentration (33%) induced a mild and reproducible bronchoconstriction that slowly developed and reached its peak (DeltaRL = 67 +/- 19%, DeltaCdyn = -29 +/- 6%) after a delay of >1 min. After exposure to O3 the same cigarette smoke inhalation challenge evoked an intense bronchoconstriction that occurred more rapidly, reaching its peak (DeltaRL = 620 +/- 224%, DeltaCdyn = -35 +/- 7%) within 20 s, and was sustained for >2 min. By contrast, sham exposure to room air did not alter the bronchomotor response to cigarette smoke challenge. Pretreatment with CP-99994 and SR-48968, the selective antagonists of neurokinin type 1 and 2 receptors, respectively, completely blocked the enhanced responses of RL and Cdyn to cigarette smoke challenge induced by O3. These results show that O3 exposure induces airway hyperresponsiveness to inhaled cigarette smoke and that the enhanced responses result primarily from the bronchoconstrictive effect of endogenous tachykinins.
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Affiliation(s)
- Z X Wu
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
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