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Guo X, Olajuyin A, Tucker TA, Idell S, Qian G. BRD4 as a Therapeutic Target in Pulmonary Diseases. Int J Mol Sci 2023; 24:13231. [PMID: 37686037 PMCID: PMC10487829 DOI: 10.3390/ijms241713231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
Bromodomain and extra-terminal domain (BET) proteins are epigenetic modulators that regulate gene transcription through interacting with acetylated lysine residues of histone proteins. BET proteins have multiple roles in regulating key cellular functions such as cell proliferation, differentiation, inflammation, oxidative and redox balance, and immune responses. As a result, BET proteins have been found to be actively involved in a broad range of human lung diseases including acute lung inflammation, asthma, pulmonary arterial hypertension, pulmonary fibrosis, and chronic obstructive pulmonary disease (COPD). Due to the identification of specific small molecular inhibitors of BET proteins, targeting BET in these lung diseases has become an area of increasing interest. Emerging evidence has demonstrated the beneficial effects of BET inhibitors in preclinical models of various human lung diseases. This is, in general, largely related to the ability of BET proteins to bind to promoters of genes that are critical for inflammation, differentiation, and beyond. By modulating these critical genes, BET proteins are integrated into the pathogenesis of disease progression. The intrinsic histone acetyltransferase activity of bromodomain-containing protein 4 (BRD4) is of particular interest, seems to act independently of its bromodomain binding activity, and has implication in some contexts. In this review, we provide a brief overview of the research on BET proteins with a focus on BRD4 in several major human lung diseases, the underlying molecular mechanisms, as well as findings of targeting BET proteins using pharmaceutical inhibitors in different lung diseases preclinically.
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Affiliation(s)
| | | | | | | | - Guoqing Qian
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA; (X.G.); (A.O.); (T.A.T.); (S.I.)
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Qian L, Lu L, Huang L, Wen Q, Xie J, Jin W, Li H, Jiang L. The effect of neonatal maternal separation on short-chain fatty acids and airway inflammation in adult asthma mice. Allergol Immunopathol (Madr) 2019; 47:2-11. [PMID: 30458973 DOI: 10.1016/j.aller.2018.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 04/23/2018] [Accepted: 05/10/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND To investigate neonatal maternal separation (NMS) effects on airway inflammation of asthma and potential mechanism using a mouse model. METHODS 80 Balb/c neonatal male mice were randomly assigned to NMS and non-NMS groups. Feces were collected on PND21, 28, 35 and 42 to analyze microbiota and short-chain fatty acids (SCFAs). Non-NMS group were then divided into control (group A) and asthma groups (group B), while NMS group was assigned to NMS+asthma (group C) and NMS+SCFAs+asthma groups (group D). Inflammatory cells and eosinophils (EOS) in bronchoalveolar lavage fluid (BALF) were assessed. Pathological changes and cytokines in lung tissue were observed. Protein expression of Occludin and E-cadherin in airway epithelial was examined. RESULTS The number of S', diversity index H' and dominance index D', as well as content butyric acid in NMS group C were significantly lower than non-NMS group B (p<0.05). Mice in group C had a higher level of inflammatory cells and EOS compared with group A, B and D. EOS moderate infiltration was found in mice of group B, C and D. Mice in group C had significantly higher levels of cytokines and showed slightly increased bronchial epithelium goblet cells and a small amount of visceral secretions. Occludin and E-cadherin expression in lung in B, C and D groups was depressed, and protein level in group C was significantly lower than group B and D. CONCLUSIONS NMS is associated with exacerbated inflammation of adult asthma by changing intestinal microflora resulting in butanoic acid decline and airway epithelial barrier damage.
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Kaphalia L, Kalita M, Kaphalia BS, Calhoun WJ. Effects of acute ethanol exposure on cytokine production by primary airway smooth muscle cells. Toxicol Appl Pharmacol 2015; 292:85-93. [PMID: 26721307 DOI: 10.1016/j.taap.2015.12.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 12/08/2015] [Accepted: 12/17/2015] [Indexed: 01/17/2023]
Abstract
Both chronic and binge alcohol abuse can be significant risk factors for inflammatory lung diseases such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. However, metabolic basis of alcohol-related lung disease is not well defined, and may include key metabolites of ethanol [EtOH] in addition to EtOH itself. Therefore, we investigated the effects of EtOH, acetaldehyde [ACE], and fatty acid ethyl esters [FAEEs] on oxidative stress, endoplasmic reticulum (ER) stress, AMP-activated protein kinase (AMPK) signaling and nuclear translocation of phosphorylated (p)-NF-κB p65 in primary human airway smooth muscle (HASM) cells stimulated to produce cytokines using LPS exposure. Both FAEEs and ACE induced evidence of cellular oxidative stress and ER stress, and increased p-NF-κB in nuclear extracts. EtOH and its metabolites decreased p-AMPKα activation, and induced expression of fatty acid synthase, and decreased expression of sirtuin 1. In general, EtOH decreased secretion of IP-10, IL-6, eotaxin, GCSF, and MCP-1. However, FAEEs and ACE increased these cytokines, suggesting that both FAEEs and ACE as compared to EtOH itself are proinflammatory. A direct effect of EtOH could be consistent with blunted immune response. Collectively, these two features of EtOH exposure, coupled with the known inhibition of innate immune response in our model might explain some clinical manifestations of EtOH exposure in the lung.
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Affiliation(s)
- Lata Kaphalia
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Mridul Kalita
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Bhupendra S Kaphalia
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - William J Calhoun
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States.
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Deacon K, Knox AJ. Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2015; 309:L237-49. [PMID: 26047642 DOI: 10.1152/ajplung.00390.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/02/2015] [Indexed: 12/14/2022] Open
Abstract
Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production.
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Affiliation(s)
- Karl Deacon
- Division of Respiratory Medicine, Centre for Respiratory Research, University of Nottingham
| | - Alan J Knox
- Division of Respiratory Medicine, Centre for Respiratory Research, University of Nottingham
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Rosenkranz SK, Rosenkranz RR, Hastmann TJ, Harms CA. High-intensity training improves airway responsiveness in inactive nonasthmatic children: evidence from a randomized controlled trial. J Appl Physiol (1985) 2012; 112:1174-83. [PMID: 22241059 DOI: 10.1152/japplphysiol.00663.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PURPOSE the relationship between physical activity and airway health in children is not well understood. The purpose of this study was to determine whether 8 wk of high-intensity exercise training would improve airway responsiveness in prepubescent, nonasthmatic, inactive children. METHODS 16 healthy, prepubescent children were randomized [training group (TrG) n = 8, control group (ConG) n = 8]. Prior to and following 8 wk of training (or no training), children completed pulmonary function tests (PFTs): forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), forced expiratory flow at 25-75% of vital capacity (FEF(25-75)), and exhaled nitric oxide (FENO). Children completed an incremental cycle Vo(2max) test, eucapnic voluntary hyperventilation (EVH), anthropometric tests, and blood tests to determine fasting blood glucose, total cholesterol, HDL, LDL, and triglycerides. Body fat percentage was determined using dual-energy X-ray absorptiometry pretraining and bioelectrical impedance pre- and posttraining. RESULTS there were no differences (P > 0.05) in anthropometric measures or PFTs between TrG and ConG at baseline. In the TrG, there was a significant increase in Vo(2max) (∼24%) and a decrease in total cholesterol (∼13%) and LDL cholesterol (∼35%) following training. There were improvements (P < 0.05) in ΔFEV(1) both postexercise (pre: -7.60 ± 2.10%, post: -1.10 ± 1.80%) and post-EVH (pre: -6.71 ± 2.21%, post: -1.41 ± 1.58%) with training. The ΔFEF(25-75) pre-post exercise also improved with training (pre: -16.10 ± 2.10%, post: -6.80 ± 1.80%; P < 0.05). Lower baseline body fat percentages were associated with greater improvements in pre-post exercise ΔFEV(1) following training (r = -0.80, P < 0.05). CONCLUSION these results suggest that in nonasthmatic prepubescent children, inactivity negatively impacts airway responsiveness, which can be improved with high-intensity training. Excess adiposity, however, may constrain these improvements.
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Affiliation(s)
- Sara K Rosenkranz
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA.
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Beta-Adrenergic Agonists. Pharmaceuticals (Basel) 2010; 3:1016-1044. [PMID: 27713285 PMCID: PMC4034018 DOI: 10.3390/ph3041016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 03/15/2010] [Accepted: 03/26/2010] [Indexed: 12/31/2022] Open
Abstract
Inhaled β2-adrenoceptor (β2-AR) agonists are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptoms-relievers and, in combination with inhaled corticosteroids, as disease-controllers. In this article, we first review the basic mechanisms by which the β2-adrenergic system contributes to the control of airway smooth muscle tone. Then, we go on describing the structural characteristics of β2-AR and the molecular basis of G-protein-coupled receptor signaling and mechanisms of its desensitization/ dysfunction. In particular, phosphorylation mediated by protein kinase A and β-adrenergic receptor kinase are examined in detail. Finally, we discuss the pivotal role of inhaled β2-AR agonists in the treatment of asthma and the concerns about their safety that have been recently raised.
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Baroffio M, Barisione G, Crimi E, Brusasco V. Noninflammatory mechanisms of airway hyper-responsiveness in bronchial asthma: an overview. Ther Adv Respir Dis 2009; 3:163-74. [PMID: 19661157 DOI: 10.1177/1753465809343595] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Airway hyper-responsiveness (AHR) is a cardinal feature of asthma. Its absence has been considered useful in excluding asthma, whereas it may be present in other diseases such as atopic rhinitis and chronic obstructive pulmonary disease. AHR is often considered an epiphenomenon of airway inflammation. Actually, the response of airways to constrictor stimuli is modulated by a complex array of factors, some facilitating and others opposing airway narrowing. Thus, it has been suggested that AHR, and perhaps asthma, might be present even without or before the development of airway inflammation. We begin this review by highlighting some terminological and methodological issues concerning the measurement of AHR. Then we describe the neurohumoral mechanisms controlling airway tone. Finally, the pivotal role of airway smooth muscle and internal and external modulation of airway caliber in vivo are discussed in detail.
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Affiliation(s)
- Michele Baroffio
- Dipartimento di Medicina Interna, Università di Genova, Genova, Italy.
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Ceresa CC, Knox AJ, Johnson SR. Use of a three-dimensional cell culture model to study airway smooth muscle-mast cell interactions in airway remodeling. Am J Physiol Lung Cell Mol Physiol 2009; 296:L1059-66. [PMID: 19346431 DOI: 10.1152/ajplung.90445.2008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased airway smooth muscle (ASM) mass and infiltration by mast cells are key features of airway remodeling in asthma. We describe a model to investigate the relationship between ASM, the extracellular matrix, mast cells, and airway remodeling. ASM cells were cultured in a three-dimensional (3-D) collagen I gel (3-D culture) alone or with mast cells. Immunocytochemistry and Western blotting of ASM in 3-D cultures revealed a spindle-shaped morphology and significantly lower alpha-smooth muscle actin and vimentin expression than in ASM cultured in monolayers on collagen type I or plastic (2-D culture). In 3-D cultures, basal ASM proliferation, examined by Ki67 immunocytochemistry, was reduced to 33 +/- 7% (P < 0.05) of that in 2-D cultures. The presence of mast cells in cocultures increased ASM proliferation by 1.8-fold (P < 0.05). Gelatin zymography revealed more active matrix metalloproteinase (MMP)-2 in 3-D than in 2-D culture supernatants over 7 days. Functional MMP activity was examined by gel contraction. The spontaneous gel contraction over 7 days was significantly inhibited by the MMP inhibitor ilomastat. Mast cell coculture enhanced ASM gel contraction by 22 +/- 16% (not significant). Our model shows that ASM has different morphology, with lower contractile protein expression and basal proliferation in 3-D culture. Compared with standard techniques, ASM synthetic function, as shown by MMP production and activity, is sustained over longer periods. The presence of mast cells in the 3-D model enhanced ASM proliferation and MMP production. Airway remodeling in asthma may be more accurately modeled by our system than by standard culture systems.
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Affiliation(s)
- Claudia C Ceresa
- Divisions of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, United Kingdom
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Henderson N, Markwick LJ, Elshaw SR, Freyer AM, Knox AJ, Johnson SR. Collagen I and thrombin activate MMP-2 by MMP-14-dependent and -independent pathways: implications for airway smooth muscle migration. Am J Physiol Lung Cell Mol Physiol 2006; 292:L1030-8. [PMID: 17189319 DOI: 10.1152/ajplung.00317.2006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased proinflammatory mediators and ECM deposition are key features of the airways in asthma. Matrix metalloproteinases (MMPs) are produced by airway smooth muscle (ASM) cells and have multiple roles in inflammation and tissue remodeling. We hypothesized that components of the asthmatic airway would stimulate MMP production and activation by ASM and contribute to airway remodeling. We measured human ASM-derived MMP mRNA, protein, and activity by real-time RT-PCR, zymography, Western blotting, and MMP activity assay. Collagen I and thrombin caused a synergistic increase in MMP-2 protein and total MMP activity but paradoxically decreased MMP-2 mRNA. Additionally, collagen I activated MMP-2 in culture supernatants independent of the cell surface. Together, collagen I and thrombin strongly enhanced MMP-14 mRNA and protein but had no effect individually, suggesting increased MMP-14, the activating protease for MMP-2, may be partially responsible for MMP-2 activation. Furthermore, collagen I reduced tissue inhibitor of metalloproteinase-2 protein (TIMP-2). We examined the role of MMPs in functions of ASM related to airway remodeling and found migration and proliferation were MMP dependent, whereas adhesion and apoptosis were not. Ilomastat inhibited migration by 25%, which was also inhibited by TIMPs 1-4 and increased by the MMP-2 activator thrombin. These in vitro findings suggest that the environment within the airways of patients with asthma enhances MMP-2 and -14 protein and activity by a complex interaction of transcriptional and posttranscriptional mechanisms, which may contribute to ASM migration.
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Affiliation(s)
- Neil Henderson
- Division of Therapeutics and Molecular Medicine, University Hospital, Queens Medical Centre, Nottingham, United Kingdom
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Bergeron C, Boulet LP. Structural changes in airway diseases: characteristics, mechanisms, consequences, and pharmacologic modulation. Chest 2006; 129:1068-87. [PMID: 16608960 DOI: 10.1378/chest.129.4.1068] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In airway diseases such as asthma and COPD, specific structural changes may be observed, very likely secondary to an underlying inflammatory process. Although it is still controversial, airway remodeling may contribute to the development of these diseases and to their clinical expression and outcome. Airway remodeling has been described in asthma in various degrees of severity, and correlations have been found between such features as increase in subepithelial collagen or proteoglycan deposits and airway responsiveness. Although the clinical significance of airway remodeling remains a matter of debate, it has been suggested as a potential target for treatments aimed at reducing asthma severity, improving its control, and possibly preventing its development. To date, drugs used to treat airway diseases have a little influence on airway structural changes. More research should be done to identify key changes, valuable treatments, and proper interventional timing to counteract these changes. The potential of novel therapeutic agents to reverse or prevent airway remodeling is an exciting avenue and warrants further evaluation.
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Shi XZ, Sarna SK. Transcriptional regulation of inflammatory mediators secreted by human colonic circular smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2005; 289:G274-84. [PMID: 15790759 DOI: 10.1152/ajpgi.00512.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We investigated the transcriptional regulation of secretion of pro- and anti-inflammatory mediators by human colonic circular smooth muscle cells (HCCSMC) in response to tumor necrosis factor (TNF)-alpha. Gene chip array analysis indicated that HCCSMC express a specific panel of 11 cytokines, chemokines, and cell adhesion molecules in a time-dependent manner in response to TNF-alpha. The chip array data were supported by quantitative analysis of mRNA and protein expressions of interleukin (IL)-6, IL-8, intercellular adhesion molecule (ICAM)-1 and IL-11. The proinflammatory mediators were expressed early, whereas the anti-inflammatory cytokine IL-11 was expressed late after TNF-alpha treatment. The expression of ICAM-1 on HCCSMC increased lymphocyte adhesion to these cells, which was blocked by pretreatment with antibody to ICAM-1. TNF-alpha acted on both R(1) and R(2) receptors to induce the expression of ICAM-1. Pretreatment of HCCSMC with antisense oligonucleotides to p65 nuclear factor-kappaB (NF-kappaB) blocked the expression of ICAM-1, whereas pretreatment with antisense oligonucleotides to p50 NF-kappaB had little effect. The overexpression of p65 NF-kappaB enhanced the constitutive expression of ICAM-1, and TNF-alpha treatment had no further effect. The delayed expression of endogenous IL-11 limited the expression of ICAM-1, and pretreatment of HCCSMC with antisense oligonucleotides to IL-11 enhanced it. We conclude that TNF-alpha induces gene expression in HCCSMC for programmed synthesis and release of pro- and anti-inflammatory mediators.
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Affiliation(s)
- Xuan-Zheng Shi
- Division of Gastroenterology, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, 9.138 Medical Research Bldg., Galveston, TX 77555-1064, USA
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Miller JD, Cox G, Vincic L, Lombard CM, Loomas BE, Danek CJ. A prospective feasibility study of bronchial thermoplasty in the human airway. Chest 2005; 127:1999-2006. [PMID: 15947312 DOI: 10.1378/chest.127.6.1999] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Bronchial thermoplasty is a novel procedure being developed as a potential treatment for asthma. Experience with animal studies has enabled development of appropriate reliable equipment, definition of therapeutic parameters, and descriptions of tissue effects of treatment. STUDY OBJECTIVES This study was undertaken to assess the feasibility and general safety of the application of bronchial thermoplasty in the human airway, and to determine if the reduction in airway smooth muscle seen in animal studies could be replicated. DESIGN A prospective study. SETTING Academic thoracic surgery center. PARTICIPANTS Nine patients scheduled to undergo lung resection for suspected or proven lung cancer. INTERVENTIONS Bronchial thermoplasty was performed during routine preoperative bronchoscopy up to 3 weeks prior to prescheduled lung resection. Treatment was limited to areas of the segmental bronchi within the lobe that was to be removed. Treated airways were inspected via bronchoscopy at the time of thoracotomy, and were examined histologically following surgical resection. RESULTS There were no adverse clinical effects of the procedure, including no new symptoms and no unscheduled visits for medical care. Treated sites exhibited slight redness and edema of the mucosa within 2 weeks of treatment, and appeared normal at later time points. There was narrowing (visually estimated at 25 to 50%) in four airways in two subjects examined at 5 days and 13 days after treatment, with excess mucus in two of these airways. There was no bronchoscopic evidence of scarring in any of the airways examined. Histologic examination showed a reduction in airway smooth muscle, and the extent of the treatment effect was confined to the airway wall and the immediate peribronchial region. CONCLUSION Application of bronchial thermoplasty to the human airway appears to be well tolerated. Treatment resulted in significant reduction of smooth muscle mass in the airways. Bronchial thermoplasty may provide therapeutic benefit in disease states such as asthma.
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Affiliation(s)
- John D Miller
- Division of Thoracic Surgery, St. Joseph's Healthcare, 50 Charlton Ave East, Hamilton, ON, Canada L8N 4A6.
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Clarke DL, Belvisi MG, Smith SJ, Hardaker E, Yacoub MH, Meja KK, Newton R, Slater DM, Giembycz MA. Prostanoid receptor expression by human airway smooth muscle cells and regulation of the secretion of granulocyte colony-stimulating factor. Am J Physiol Lung Cell Mol Physiol 2005; 288:L238-50. [PMID: 15640521 DOI: 10.1152/ajplung.00313.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The prostanoid receptors on human airway smooth muscle cells (HASMC) that augment the release by IL-1β of granulocyte colony-stimulating factor (G-CSF) have been characterized and the signaling pathway elucidated. PCR of HASM cDNA identified products corresponding to EP2, EP3, and EP4receptor subtypes. These findings were corroborated at the protein level by immunocytochemistry. IL-1β promoted the elaboration of G-CSF, which was augmented by PGE2. Cicaprost (IP receptor agonist) was approximately equiactive with PGE2, whereas PGD2, PGF2α, and U-46619 (TP receptor agonist) were over 10-fold less potent. Neither SQ 29,548 nor BW A868C (TP and DP1receptor antagonists, respectively) attenuated the enhancement of G-CSF release evoking any of the prostanoids studied. With respect to PGE2, the EP receptor agonists 16,16-dimethyl PGE2(nonselective), misoprostol (EP2/EP3selective), 17-phenyl-ω-trinor PGE2(EP1selective), ONO-AE1-259, and butaprost (both EP2selective) were full agonists at enhancing G-CSF release. AH 6809 (10 μM) and L-161,982 (2 μM), which can be used in HASMC as selective EP2and EP4receptor antagonists, respectively, failed to displace to the right the PGE2concentration-response curve that described the augmented G-CSF release. In contrast, AH 6809 and L-161,982 in combination competitively antagonized PGE2-induced G-CSF release. Augmentation of G-CSF release by PGE2was mimicked by 8-BrcAMP and abolished in cells infected with an adenovirus vector encoding an inhibitor protein of cAMP-dependent protein kinase (PKA). These data demonstrate that PGE2facilitates G-CSF secretion from HASMC through a PKA-dependent mechanism by acting through EP2and EP4prostanoid receptors and that effective antagonism is realized only when both subtypes are blocked concurrently.
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Affiliation(s)
- Deborah L Clarke
- Thoraic Medicine, National Heart and Lung Institute, Imperial College London, London, UK
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Singer CA, Salinthone S, Baker KJ, Gerthoffer WT. Synthesis of immune modulators by smooth muscles. Bioessays 2004; 26:646-55. [PMID: 15170862 DOI: 10.1002/bies.20041] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The primary function of smooth muscle cells is to contract and alter the stiffness or diameter of hollow organs such as blood vessels, the airways and the gastrointestinal and urogenital tracts. In addition to purely structural functions, smooth muscle cells may play important metabolic roles, particularly in various inflammatory responses. In cell culture, these cells have been shown to be metabolically dynamic, synthesizing and secreting extracellular matrix proteins, glycosaminoglycans and a wide variety of cell-cell signaling proteins, such as interleukins, chemokines and peptide growth factors. Secreted cell signaling proteins participate in the inflammatory response of smooth muscle-containing organs, and some can also stimulate smooth muscle migration, proliferation and contraction. The cellular signaling pathways controlling synthesis of these signaling proteins are similar to those used by cells mediating innate immunity and may contribute to pathogenesis of diverse diseases including atherosclerosis, asthma, inflammatory bowel diseases and preterm labor. Appreciating the role of smooth muscle cells in these diseases may lead to better understanding of the beneficial effects of anti-inflammatory drugs as well as identification of new targets for anti-inflammatory therapy.
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Affiliation(s)
- Cherie A Singer
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0270, USA
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Singer CA, Baker KJ, McCaffrey A, AuCoin DP, Dechert MA, Gerthoffer WT. p38 MAPK and NF-kappaB mediate COX-2 expression in human airway myocytes. Am J Physiol Lung Cell Mol Physiol 2003; 285:L1087-98. [PMID: 12871860 DOI: 10.1152/ajplung.00409.2002] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously demonstrated that p38 and extracellular signal-regulated protein kinase (ERK) mitogen-activated protein kinases (MAPK) are components of proinflammatory induced cytokine expression in human airway myocytes. The experiments described here further these studies by examining p38 MAPK and NF-kappaB regulation of cyclooxygenase-2 (COX-2) expression in response to a complex inflammatory stimulus consisting of 10 ng/ml interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha), and interferon (IFN)-gamma. COX-2 expression was induced with this stimulus in a time-dependent manner, with maximal expression seen 12-20 h after treatment. Semiquantitative RT-PCR and immunoblotting experiments demonstrate decreased COX-2 expression following treatment with the p38 MAPK inhibitor SB-203580 (25 microM) or the proteosome inhibitor MG-132 (1 microM). SB-203580 did not affect cytokine-stimulated IkappaBalpha degradation, NF-kappaB nuclear binding activity, or NF-kappaB-dependent signaling from the COX-2 promoter, indicating that p38 MAPK and NF-kappaB may affect COX-2 expression via separate signaling pathways. SB-203580, but not MG-132, also increased the initial rate of COX-2 mRNA decay, indicating p38 MAPK, but not NF-kappaB, participates in the regulation of COX-2 mRNA stability. These findings suggest that although p38 MAPK and NF-kappaB signaling regulate steady-state levels of COX-2 expression, p38 MAPK additionally affects stability of COX-2 mRNA in cytokine-stimulated human airway myocytes.
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Affiliation(s)
- Cherie A Singer
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada 89557-0046, USA.
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Brusasco V, Pellegrino R. Complexity of factors modulating airway narrowing in vivo: relevance to assessment of airway hyperresponsiveness. J Appl Physiol (1985) 2003; 95:1305-13. [PMID: 12909604 DOI: 10.1152/japplphysiol.00001.2003] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In vivo, the airway response to constrictor stimuli is the net result of a complex array of factors, some facilitating and some opposing airway narrowing, which makes the interpretation of bronchial challenges far from being straightforward. This review begins with a short description of the complex mechanisms of airway smooth muscle activation and force generation as the starting events for airway narrowing. It then focuses on gain factors modulating airway smooth muscle shortening and on the geometric factors determining the magnitude of reduction in airway caliber in vivo. Finally, in light of the evidence that mechanical modulation of airway smooth muscle tone and airway narrowing is at least as important as the inflammatory contractile mediators in the pathogenesis of airway hyper-responsiveness, the implications for the interpretation of bronchial challenges in clinical settings are discussed.
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Affiliation(s)
- Vito Brusasco
- Dipartimento di Medicina Interna, Università di Genova, 16132 Genova, Italy.
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Abstract
Asthma is one of the commonest chronic diseases of affluent societies. The striking increase in prevalence of asthma over recent decades and the rarity of this disease in less affluent populations confirms the importance of environmental factors in the cause of asthma--although which environmental factors are responsible is still not clear. Family studies show that genetic factors are also important in determining individual susceptibility to asthma, with results of genetic studies suggesting that there are many genes with moderate effects rather than a few major genes. Asthmatic airways show inflammation and remodelling, with CD4+ helper cells, mast cells, and eosinophils characterising the inflammatory response. Inhaled corticosteroids remain the cornerstone of treatment with the addition of long-acting beta agonists as the next step if symptoms continue. Leukotriene antagonists, the only new drugs to reach the market in the past decade, have modest effects. However, a better understanding of the mechanisms underlying asthma and the genetic and environmental factors that predispose individuals to asthma should lead to better preventative strategies and new therapeutic approaches.
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Affiliation(s)
- A E Tattersfield
- Division of Respiratory Medicine, Clinical Sciences Building, City Hospital, Nottingham, UK.
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Amrani Y, Chen H, Panettieri RA. Activation of tumor necrosis factor receptor 1 in airway smooth muscle: a potential pathway that modulates bronchial hyper-responsiveness in asthma? Respir Res 2000; 1:49-53. [PMID: 11667965 PMCID: PMC59542 DOI: 10.1186/rr12] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2000] [Accepted: 06/13/2000] [Indexed: 11/27/2022] Open
Abstract
The cellular and molecular mechanisms that are involved in airway hyper-responsiveness are unclear. Current studies suggest that tumor necrosis factor (TNF)-alpha, a cytokine that is produced in considerable quantities in asthmatic airways, may potentially be involved in the development of bronchial hyper-responsiveness by directly altering the contractile properties of the airway smooth muscle (ASM). The underlying mechanisms are not known, but growing evidence now suggests that most of the biologic effects of TNF-alpha on ASM are mediated by the p55 receptor or tumor necrosis factor receptor (TNFR)1. In addition, activation of TNFR1 coupled to the tumor necrosis factor receptor-associated factor (TRAF)2-nuclear factor-kappaB (NF-kappaB) pathway alters calcium homeostasis in ASM, which appears to be a new potential mechanism underlying ASM hyper-responsiveness.
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Affiliation(s)
- Y Amrani
- Pulmonary, Allergy and Critical Care Division, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104-6160, USA.
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Blease K, Lukacs NW, Hogaboam CM, Kunkel SL. Chemokines and their role in airway hyper-reactivity. Respir Res 2000; 1:54-61. [PMID: 11667966 PMCID: PMC59544 DOI: 10.1186/rr13] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2000] [Revised: 06/20/2000] [Accepted: 06/20/2000] [Indexed: 01/22/2023] Open
Abstract
Airway hyper-reactivity is a characteristic feature of many inflammatory lung diseases and is defined as an exaggerated degree of airway narrowing. Chemokines and their receptors are involved in several pathological processes that are believed to contribute to airway hyper-responsiveness, including recruitment and activation of inflammatory cells, collagen deposition and airway wall remodeling. These proteins are therefore thought to represent important therapeutic targets in the treatment of airway hyper-responsiveness. This review highlights the processes thought to be involved in airway hyper-responsiveness in allergic asthma, and the role of chemokines in these processes. Overall, the application of chemokines to the prevention or treatment of airway hyper-reactivity has tremendous potential.
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Affiliation(s)
- K Blease
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
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