Cigarette smoke and lipopolysaccharide induce a proliferative airway smooth muscle phenotype

Background: A major feature of chronic obstructive pulmonary disease (COPD) is airway remodelling, which includes an increased airway smooth muscle (ASM) mass. The mechanisms underlying ASM remodelling in COPD are currently unknown. We hypothesized that cigarette smoke (CS) and/or lipopolysaccharide (LPS), a major constituent of CS, organic dust and gram-negative bacteria, that may be involved in recurrent airway infections and exacerbations in COPD patients, would induce phenotype changes of ASM. Methods: To this aim, using cultured bovine tracheal smooth muscle (BTSM) cells and tissue, we investigated the direct effects of CS extract (CSE) and LPS on ASM proliferation and contractility. Results: Both CSE and LPS induced a profound and concentration-dependent increase in DNA synthesis in BTSM cells. CSE and LPS also induced a significant increase in BTSM cell number, which was associated with increased cyclin D1 expression and dependent on activation of ERK 1/2 and p38 MAP kinase. Consistent with a shift to a more proliferative phenotype, prolonged treatment of BTSM strips with CSE or LPS significantly decreased maximal methacholine- and KCl-induced contraction. Conclusions: Direct exposure of ASM to CSE or LPS causes the induction of a proliferative, hypocontractile ASM phenotype, which may be involved in airway remodelling in COPD

Cigarette smoke induces β2-integrin-dependent neutrophil migration across human endothelium

<p>Abstract</p> <p>Background</p> <p>Cigarette smoking induces peripheral inflammatory responses in all smokers and is the major risk factor for neutrophilic lung disease such as chronic obstructive pulmonary disease. The aim of this study was to investigate the effect of cigarette smoke on neutrophil migration and on β₂-integrin activation and function in neutrophilic transmigration through endothelium.</p> <p>Methods and results</p> <p>Utilizing freshly isolated human PMNs, the effect of cigarette smoke on migration and β₂-integrin activation and function in neutrophilic transmigration was studied. In this report, we demonstrated that cigarette smoke extract (CSE) dose dependently induced migration of neutrophils <it>in vitro</it>. Moreover, CSE promoted neutrophil adherence to fibrinogen. Using functional blocking antibodies against CD11b and CD18, it was demonstrated that Mac-1 (CD11b/CD18) is responsible for the cigarette smoke-induced firm adhesion of neutrophils to fibrinogen. Furthermore, neutrophils transmigrated through endothelium by cigarette smoke due to the activation of β₂-integrins, since pre-incubation of neutrophils with functional blocking antibodies against CD11b and CD18 attenuated this transmigration.</p> <p>Conclusion</p> <p>This is the first study to describe that cigarette smoke extract induces a direct migratory effect on neutrophils and that CSE is an activator of β₂-integrins on the cell surface. Blocking this activation of β₂-integrins might be an important target in cigarette smoke induced neutrophilic diseases.</p

The Longleaf Tree-Ring Network: Reviewing and expanding the utility of Pinus palustris Mill. Dendrochronological data

The longleaf pine (Pinus palustris Mill.) and related ecosystem is an icon of the southeastern United States (US). Once covering an estimated 37 million ha from Texas to Florida to Virginia, the near-extirpation of, and subsequent restoration efforts for, the species has been well-documented over the past ca. 100 years. Although longleaf pine is one of the longest-lived tree species in the southeastern US—with documented ages of over 400 years—its use has not been reviewed in the field of dendrochronology. In this paper, we review the utility of longleaf pine tree-ring data within the applications of four primary, topical research areas: climatology and paleoclimate reconstruction, fire history, ecology, and archeology/cultural studies. Further, we highlight knowledge gaps in these topical areas, for which we introduce the Longleaf Tree-Ring Network (LTRN). The overarching purpose of the LTRN is to coalesce partners and data to expand the scientific use of longleaf pine tree-ring data across the southeastern US. As a first example of LTRN analytics, we show that the development of seasonwood chronologies (earlywood width, latewood width, and total width) enhances the utility of longleaf pine tree-ring data, indicating the value of these seasonwood metrics for future studies. We find that at 21 sites distributed across the species’ range, latewood width chronologies outperform both their earlywood and total width counterparts in mean correlation coefficient (RBAR = 0.55, 0.46, 0.52, respectively). Strategic plans for increasing the utility of longleaf pine dendrochronology in the southeastern US include [1] saving remnant material (e.g., stumps, logs, and building construction timbers) from decay, extraction, and fire consumption to help extend tree-ring records, and [2] developing new chronologies in LTRN spatial gaps to facilitate broad-scale analyses of longleaf pine ecosystems within the context of the topical groups presented

Water-pipe smoke condensate increases the internalization of Mycobacterium Bovis of type II alveolar epithelial cells (A549)

Background: Tuberculosis (TB) is a major global health problem, and there is an association between tobacco smoke and TB. Water pipe smoking has become an increasing problem not only in Middle Eastern countries but also globally because users consider it as safer than cigarettes. The presence of high levels of toxic substances in water-pipe smoke may be a predisposing factor that enhances the incidence of pulmonary disorders. For example, uncontrolled macropinocytosis in alveolar epithelial cells following exposure to water-pipe smoke may predispose subjects to pulmonary infection. Here, we studied the effects of water-pipe condense (WPC) on the internalization of Mycobacterium Bovis BCG by macropinocytosis in the alveolar epithelial cell line A549. Methods: A549 cells were exposed to WPC (4 mg/ml) for 24, 48, 72 and 96 h. Cell viability was studied using the methyl thiazolyldipenyl-tetrazolium bromide (MTT) reduction assay and proliferation by bromodeoxyUridine (BrdU) incorporation. Cells were exposed to FITC-Dextran (1 mg/ml) (as a control) and FITC-BCG (MOI = 10) for 20 min at 37 ° Cbeforecellswere collected and the uptake of BCG-FITC determined by flow cytometry. Similar experiments were performed at 4 ° Casacontrol . The Rho-associated protein kinase (ROCK) inhibitor Y-27632 (1 μ M) was used to assess the mechanism by which WPC enhanced BCG uptake. Results: WPC (4 mg/ml) increased the uptake of BCG-FITC after 72 (1.3 ± 0.1 fold, p < 0.05) and 96 (1.4 ± 0.05 fold, p < 0.05) hours. No effect on BCG-FITC uptake was observed at 24 or 48 h. WPC also significantly increased the uptake of FITC-Dextran (2.9 ± 0.3 fold, p < 0.05) after 24 h. WPC significantly decreased cell viability after 24 (84 ± 2%, p < 0.05), 48 (78±, 3%, p < 0.05), 72 (64 ± 2%, p < 0.05) and 96 h (45 ± 2%, p < 0.05). Y-27632 completely attenuated the increased uptake of BCG by WPC. Cell proliferation showed a decreasing trend in a time-dependent manner with WPC exposure. Conclusion: WPC exposure increased epithelial cell endocytosis activity and death as well as enhancing their capacity for macropinocytosis. Our in vitro data indicates possible harmful effects of WPC on the ability of lung epithelial cells to phagocytose mycobacterium

A proposed framework to evaluate the quality and reliability of targeted metabolomics assays from the UK Consortium on Metabolic Phenotyping (MAP/UK).

Targeted metabolite assays that measure tens or hundreds of pre-selected metabolites, typically using liquid chromatography-mass spectrometry, are increasingly being developed and applied to metabolic phenotyping studies. These are used both as standalone phenotyping methods and for the validation of putative metabolic biomarkers obtained from untargeted metabolomics studies. However, there are no widely accepted standards in the scientific community for ensuring reliability of the development and validation of targeted metabolite assays (referred to here as 'targeted metabolomics'). Most current practices attempt to adopt, with modifications, the strict guidance provided by drug regulatory authorities for analytical methods designed largely for measuring drugs and other xenobiotic analytes. Here, the regulatory guidance provided by the European Medicines Agency, US Food and Drug Administration and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use are summarized. In this Perspective, we have adapted these guidelines and propose a less onerous 'tiered' approach to evaluate the reliability of a wide range of metabolomics analyses, addressing the need for community-accepted, harmonized guidelines for tiers other than full validation. This 'fit-for-purpose' tiered approach comprises four levels-discovery, screening, qualification and validation-and is discussed in the context of a range of targeted and untargeted metabolomics assays. Issues arising with targeted multiplexed metabolomics assays, and how these might be addressed, are considered. Furthermore, guidance is provided to assist the community with selecting the appropriate degree of reliability for a series of well-defined applications of metabolomics

The Longleaf Tree-Ring Network: Reviewing and Expanding the Utility of \u3ci\u3ePinus palustris\u3c/i\u3e Mill. Dendrochronological Data

The longleaf pine (Pinus palustris Mill.) and related ecosystem is an icon of the southeastern United States (US). Once covering an estimated 37 million ha from Texas to Florida to Virginia, the near-extirpation of, and subsequent restoration efforts for, the species has been well-documented over the past ca. 100 years. Although longleaf pine is one of the longest-lived tree species in the southeastern US—with documented ages of over 400 years—its use has not been reviewed in the field of dendrochronology. In this paper, we review the utility of longleaf pine tree-ring data within the applications of four primary, topical research areas: climatology and paleoclimate reconstruction, fire history, ecology, and archeology/cultural studies. Further, we highlight knowledge gaps in these topical areas, for which we introduce the Longleaf Tree-Ring Network (LTRN). The overarching purpose of the LTRN is to coalesce partners and data to expand the scientific use of longleaf pine tree-ring data across the southeastern US. As a first example of LTRN analytics, we show that the development of seasonwood chronologies (earlywood width, latewood width, and total width) enhances the utility of longleaf pine tree-ring data, indicating the value of these seasonwood metrics for future studies. We find that at 21 sites distributed across the species’ range, latewood width chronologies outperform both their earlywood and total width counterparts in mean correlation coefficient (RBAR = 0.55, 0.46, 0.52, respectively). Strategic plans for increasing the utility of longleaf pine dendrochronology in the southeastern US include [1] saving remnant material (e.g., stumps, logs, and building construction timbers) from decay, extraction, and fire consumption to help extend tree-ring records, and [2] developing new chronologies in LTRN spatial gaps to facilitate broad-scale analyses of longleaf pine ecosystems within the context of the topical groups presented