Defective alterations in the collagen network to prostacyclin in COPD lung fibroblasts

Background

Prostacyclin analogs are potent vasodilators and possess anti-inflammatory properties. However, the effect of prostacyclin on extracellular matrix (ECM) in COPD is not well known. Collagen fibrils and proteoglycans are essential ECM components in the lung and fibroblasts are key players in regulating the homeostasis of ECM proteins. The aim was to study the synthesis of prostacyclin and its effect on fibroblast activity and ECM production, and in particular collagen I and the collagen-associated proteoglycans biglycan and decorin.

Methods

Parenchymal lung fibroblasts were isolated from lungs from COPD patients (GOLD stage IV) and from lungs and transbronchial biopsies from control subjects. The prostacyclin analog iloprost was used to study the effect of prostacyclin on ECM protein synthesis, migration, proliferation and contractile capacity of fibroblasts.

Results

TGF-β₁ stimulation significantly increased prostacyclin synthesis in fibroblasts from COPD patients (p < 0.01), but showed no effect on fibroblasts from control subjects. Collagen I synthesis was decreased by iloprost in both control and COPD fibroblasts (p < 0.05). Conversely, iloprost significantly altered biglycan and decorin synthesis in control fibroblasts, but iloprost displayed no effect on these proteoglycans in COPD fibroblasts. Proliferation rate was reduced (p < 0.05) and contractile capacity was increased in COPD fibroblasts (p < 0.05) compared to control fibroblasts. Iloprost decreased proliferative rate in control fibroblasts (p < 0.05), whereas iloprost attenuated contraction capacity in both COPD (p < 0.01) and control fibroblasts (p < 0.05).

Conclusions

Iloprost reduced collagen I synthesis and fibroblast contractility but did not affect the collagen-associated proteoglycans or proliferation rate in fibroblasts from COPD patients. Enhanced prostacyclin production could lead to improper collagen network fibrillogenesis and a more emphysematous lung structure in severe COPD patients.     

Adipose-Derived Stromal Cell Therapy Affects Lung Inflammation and Tracheal Responsiveness in Guinea Pig Model of COPD

The effects of adipose derived stromal cells (ASCs) were evaluated on tracheal responsiveness and biochemical parameters in guinea pigs model of chronic obstructive pulmonary disease (COPD). Thirty six guinea pigs were divided into 6 groups including: Control, COPD, COPD+intratracheal delivery of PBS (COPD+ITPBS), COPD+intravenous delivery of PBS (COPD+IVPBS), COPD+intratracheal delivery of ASCs (COPD+ITASC) and COPD+intravenous injection of ASCs (COPD+IVASC). COPD was induced by exposing animals to cigarette smoke for 3 months. Cell therapy was then performed and after 14 days, tracheal responsiveness, concentration of interleukin-8 (IL-8) in serum and broncho-alveolar lavage fluid (BALF), as well as total and differential white blood cells (WBC) counts were evaluated. Tracheal responsiveness, total WBC counts, neutrophil and eosinophil percentage in BALF as well as concentration of IL-8 in serum and BALF significantly increased but lymphocyte percentage decreased in COPD compared to the control group (P<0.05 to p<0.001). Cell therapy was able to restore the tracheal hyper-responsiveness and the increased IL-8 concentration in serum and BALF of COPD-ITASC but not COPD-IVASC animals (P<0.05 for all cases). Total WBC in BALF also showed a significant decrease in both treated groups and the percentages of eosinophils, neutrophils and lymphocytes in BALF were reversed in COPD-ITASC compared to COPD-ITPBS animals (P<0.05 to P<0.001). Therefore, intratracheal cell therapy with ASC can decrease tracheal hyperresponsiveness and lung inflammation in cigarette smoke induced-COPD which may be helpful in attenuation of the severity of disease in patients suffering from COPD.     

Mesenchymal stem cell-conditioned media recovers lung fibroblasts from cigarette smoke-induced damage

Cigarette smoking causes apoptotic death, senescence, and impairment of repair functions in lung fibroblasts, which maintain the integrity of alveolar structure by producing extracellular matrix (ECM) proteins. Therefore, recovery of lung fibroblasts from cigarette smoke-induced damage may be crucial in regeneration of emphysematous lung resulting from degradation of ECM proteins and subsequent loss of alveolar cells. Recently, we reported that bone marrow-derived mesenchymal stem cell-conditioned media (MSC-CM) led to angiogenesis and regeneration of lung damaged by cigarette smoke. In this study, to further investigate reparative mechanisms for MSC-CM-mediated lung repair, we attempted to determine whether MSC-CM can recover lung fibroblasts from cigarette smoke-induced damage. In lung fibroblasts exposed to cigarette smoke extract (CSE), MSC-CM, not only inhibited apoptotic death, but also induced cell proliferation and reversed CSE-induced changes in the levels of caspase-3, p53, p21, p27, Akt, and p-Akt. MSC-CM also restored expression of ECM proteins and collagen gel contraction while suppressing CSE-induced expression of cyclooxygenase-2 and microsomal PGE(2) synthase-2. The CSE-opposing effects of MSC-CM on cell fate, expression of ECM proteins, and collagen gel contraction were partially inhibited by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor. In rats, MSC-CM administration also resulted in elevation of p-Akt and restored proliferation of lung fibroblasts, which was suppressed by exposure to cigarette smoke. Taken together, these data suggest that MSC-CM may recover lung fibroblasts from cigarette smoke-induced damage, possibly through inhibition of apoptosis, induction of proliferation, and restoration of lung fibroblast repair function, which are mediated in part by the PI3K/Akt pathway.     

Decreased expression of the NF-κB family member RelB in lung fibroblasts from Smokers with and without COPD potentiates cigarette smoke-induced COX-2 expression

Background

Heightened inflammation, including expression of COX-2, is associated with COPD pathogenesis. RelB is an NF-κB family member that attenuates COX-2 in response to cigarette smoke by a mechanism that may involve the miRNA miR-146a. There is no information on the expression of RelB in COPD or if RelB prevents COX-2 expression through miR-146a.

Methods

RelB, Cox-2 and miR-146a levels were evaluated in lung fibroblasts and blood samples derived from non-smokers (Normal) and smokers (At Risk) with and without COPD by qRT-PCR. RelB and COX-2 protein levels were evaluated by western blot. Human lung fibroblasts from Normal subjects and smokers with and without COPD, along with RelB knock-down (siRNA) in Normal cells, were exposed to cigarette smoke extract (CSE) in vitro and COX-2 mRNA/protein and miR-146a levels assessed.

Results

Basal expression of RelB mRNA and protein were significantly lower in lung cells derived from smokers with and without COPD, the latter of which expressed more Cox-2 mRNA and protein in response to CSE. Knock-down of RelB in Normal fibroblasts increased Cox-2 mRNA and protein induction by CSE. Basal miR-146a levels were not different between the three groups, and only Normal fibroblasts increased miR-146a expression in response to smoke. There was a positive correlation between systemic RelB and Cox-2 mRNA levels and circulating miR-146a levels were higher only in GOLD stage I subjects.

Conclusions

Our data indicate that RelB attenuates COX-2 expression in lung structural cells, such that loss of pulmonary RelB may be an important determinant in the aberrant, heightened inflammation associated with COPD pathogenesis.     

Roflumilast N-Oxide Prevents Cytokine Secretion Induced by Cigarette Smoke Combined with LPS through JAK/STAT and ERK1/2 Inhibition in Airway Epithelial Cells

Cigarette smoke is a major cause of chronic obstructive pulmonary disease (COPD). Airway epithelial cells and macrophages are the first defense cells against cigarette smoke and these cells are an important source of pro-inflammatory cytokines. These cytokines play a role in progressive airflow limitation and chronic airways inflammation. Furthermore, the chronic colonization of airways by Gram-negative bacteria, contributes to the persistent airways inflammation and progression of COPD. The current study addressed the effects of cigarette smoke along with lipolysaccharide (LPS) in airway epithelial cells as a representative in vitro model of COPD exacerbations. Furthermore, we evaluated the effects of PDE4 inhibitor, the roflumilast N-oxide (RNO), in this experimental model. A549 cells were stimulated with cigarette smoke extract (CSE) alone (0.4% to 10%) or in combination with a low concentration of LPS (0.1 µg/ml) for 2 h or 24 h for measurement of chemokine protein and mRNAs and 5–120 min for protein phosphorylation. Cells were also pre-incubated with MAP kinases inhibitors and Prostaglandin E₂ alone or combined with RNO, before the addition of CSE+LPS. Production of cytokines was determined by ELISA and protein phosphorylation by western blotting and phospho-kinase array. CSE did not induce production of IL-8/CXCL8 and Gro-α/CXCL1 from A549 cells, but increase production of CCL2/MCP-1. However the combination of LPS 0.1 µg/ml with CSE 2% or 4% induced an important production of these chemokines, that appears to be dependent of ERK1/2 and JAK/STAT pathways but did not require JNK and p38 pathways. Moreover, RNO associated with PGE₂ reduced CSE+LPS-induced cytokine release, which can happen by occur through of ERK1/2 and JAK/STAT pathways. We report here an in vitro model that can reflect what happen in airway epithelial cells in COPD exacerbation. We also showed a new pathway where CSE+LPS can induce cytokine release from A549 cells, which is reduced by RNO.     

Novosphingobium and Its Potential Role in Chronic Obstructive Pulmonary Diseases: Insights from Microbiome Studies

Bacterial infection of lung airways underlies some of the main complications of COPD, significantly impacting disease progression and outcome. Colonization by bacteria may further synergize, amplify, or trigger pathways of tissue damage started by cigarette smoke, contributing to the characteristic airway inflammation and alveolar destruction of COPD. We sought to elucidate the presence and types of lung bacterial populations in different stages of COPD, aimed at revealing important insights into the pathobiology of the disease. Sequencing of the bacterial small subunit ribosomal RNA gene in 55 well-characterized clinical lung samples, revealed the presence of Novosphingobium spp. (>2% abundance) in lungs of patients with GOLD 3-GOLD 4 COPD, cystic fibrosis and a subset of control individuals. Novosphingobium-specific quantitative PCR was concordant with the sequence data and high levels of Novosphingobium spp. were quantifiable in advanced COPD, but not from other disease stages. Using a mouse model of subacute lung injury due to inhalation of cigarette smoke, bronchoalveolar lavage neutrophil and macrophage counts were significantly higher in mice challenged intratracheally with N. panipatense compared to control mice (p<0.01). Frequencies of neutrophils and macrophages in lung tissue were increased in mice challenged with N. panipatense at room air compared to controls. However, we did not observe an interaction between N. panipatense and subacute cigarette smoke exposure in the mouse. In conclusion, Novosphingobium spp. are present in more severe COPD disease, and increase inflammation in a mouse model of smoke exposure.     

Egr-1 regulates autophagy in cigarette smoke-induced chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by abnormal cellular responses to cigarette smoke, resulting in tissue destruction and airflow limitation. Autophagy is a degradative process involving lysosomal turnover of cellular components, though its role in human diseases remains unclear.

Methodology and Principal Findings

Increased autophagy was observed in lung tissue from COPD patients, as indicated by electron microscopic analysis, as well as by increased activation of autophagic proteins (microtubule-associated protein-1 light chain-3B, LC3B, Atg4, Atg5/12, Atg7). Cigarette smoke extract (CSE) is an established model for studying the effects of cigarette smoke exposure in vitro. In human pulmonary epithelial cells, exposure to CSE or histone deacetylase (HDAC) inhibitor rapidly induced autophagy. CSE decreased HDAC activity, resulting in increased binding of early growth response-1 (Egr-1) and E2F factors to the autophagy gene LC3B promoter, and increased LC3B expression. Knockdown of E2F-4 or Egr-1 inhibited CSE-induced LC3B expression. Knockdown of Egr-1 also inhibited the expression of Atg4B, a critical factor for LC3B conversion. Inhibition of autophagy by LC3B-knockdown protected epithelial cells from CSE-induced apoptosis. Egr-1 ^−/− mice, which displayed basal airspace enlargement, resisted cigarette-smoke induced autophagy, apoptosis, and emphysema.

Conclusions

We demonstrate a critical role for Egr-1 in promoting autophagy and apoptosis in response to cigarette smoke exposure in vitro and in vivo. The induction of autophagy at early stages of COPD progression suggests novel therapeutic targets for the treatment of cigarette smoke induced lung injury.     

CCN1 Secretion Induced by Cigarette Smoking Extracts Augments IL-8 Release from Bronchial Epithelial Cells

Inflammation involves in many cigarette smoke (CS) related diseases including the chronic obstructive pulmonary disease (COPD). Lung epithelial cell released IL-8 plays a crucial role in CS induced lung inflammation. CS and cigarette smoke extracts (CSE) both induce IL-8 secretion and subsequently, IL-8 recruits inflammatory cells into the lung parenchyma. However, the molecular and cellular mechanisms by which CSE triggers IL-8 release remain not completely understood. In this study, we identified a novel extracellular matrix (ECM) molecule, CCN1, which mediated CSE induced IL-8 secretion by lung epithelial cells. We first found that CS and CSE up-regulated CCN1 expression and secretion in lung epithelial cells in vivo and in vitro. CSE up-regulated CCN1 via induction of reactive oxygen spices (ROS) and endoplasmic reticulum (ER) stress. p38 MAPK and JNK activation were also found to mediate the signal pathways in CSE induced CCN1. CCN1 was secreted into ECM via Golgi and membrane channel receptor aquaporin4. After CSE exposure, elevated ECM CCN1 functioned via an autocrine or paracrine manner. Importantly, CCN1 activated Wnt pathway receptor LRP6, subsequently stimulated Wnt pathway component Dvl2 and triggered beta-catenin translocation from cell membrane to cytosol and nucleus. Treatment of Wnt pathway inhibitor suppressed CCN1 induced IL-8 secretion from lung epithelial cells. Taken together, CSE increased CCN1 expression and secretion in lung epithelial cells via induction of ROS and ER stress. Increased ECM CCN1 resulted in augmented IL-8 release through the activation of Wnt pathway.     

The Lung Inflammation and Skeletal Muscle Wasting Induced by Subchronic Cigarette Smoke Exposure Are Not Altered by a High-Fat Diet in Mice

Obesity and cigarette smoking independently constitute major preventable causes of morbidity and mortality and obesity is known to worsen lung inflammation in asthma. Paradoxically, higher body mass index (BMI) is associated with reduced mortality in smoking induced COPD whereas low BMI increases mortality risk. To date, no study has investigated the effect of a dietary-induced obesity and cigarette smoke exposure on the lung inflammation and loss of skeletal muscle mass in mice. Male BALB/c mice were exposed to 4 cigarettes/day, 6 days/week for 7 weeks, or sham handled. Mice consumed either standard laboratory chow (3.5 kcal/g, 12% fat) or a high fat diet (HFD, 4.3 kcal/g, 32% fat). Mice exposed to cigarette smoke for 7 weeks had significantly more inflammatory cells in the BALF (P<0.05) and the mRNA expression of pro-inflammatory cytokines and chemokines was significantly increased (P<0.05); HFD had no effect on these parameters. Sham- and smoke-exposed mice consuming the HFD were significantly heavier than chow fed animals (12 and 13%, respectively; P<0.05). Conversely, chow and HFD fed mice exposed to cigarette smoke weighed 16 and 15% less, respectively, compared to sham animals (P<0.05). The skeletal muscles (soleus, tibialis anterior and gastrocnemius) of cigarette smoke-exposed mice weighed significantly less than sham-exposed mice (P<0.05) and the HFD had no protective effect. For the first time we report that cigarette smoke exposure significantly decreased insulin-like growth factor-1 (IGF-1) mRNA expression in the gastrocnemius and tibialis anterior and IGF-1 protein in the gastrocnemius (P<0.05). We have also shown that cigarette smoke exposure reduced circulating IGF-1 levels. IL-6 mRNA expression was significantly elevated in all three skeletal muscles of chow fed smoke-exposed mice (P<0.05). In conclusion, these findings suggest that a down-regulation in local IGF-1 may be responsible for the loss of skeletal muscle mass following cigarette smoke exposure in mice.     

Down Regulation of T Cell Receptor Expression in COPD Pulmonary CD8 Cells

CD8 cells may contribute towards an autoimmune process in COPD. Down regulation of T cell receptor (TCR) signalling molecules occurs in autoimmune diseases with consequent T cell dysfunction. We hypothesise that TCR signalling is abnormal in COPD pulmonary CD8 cells. Micro-array gene expression analysis of blood and pulmonary COPD CD8 samples was performed and compared to pulmonary CD8 cells from smoker controls (S). We focused on the TCR signalling pathway, with validation of key findings using polymerase chain reaction and immunofluorescence. TCR signalling molecules in COPD pulmonary CD8 cells were down regulated compared to blood CD8 cells (CD247: fold change (FC) −2.43, Q = 0.001; LCK: FC −2.25, Q = 0.01). Micro-array analysis revealed no significant differences between COPD and S pulmonary CD8 cells. However, PCR revealed significantly lower gene expression levels of CD247 (FC −1.79, p = 0.04) and LCK (FC −1.77, p = 0.01) in COPD compared to S pulmonary CD8 cells. CD247 down regulation in COPD CD8 cells was confirmed by immunofluorescent staining of bronchoalveolar lavage cells: Significantly fewer COPD CD8 cells co-expressed CD247 compared to healthy non-smoker CD8 cells (mean 88.9 vs 75.2%, p<0.05) There is down regulation of TCR signalling molecules in COPD pulmonary CD8 cells. This may cause T cell dysfunction.     

Second-Hand Cigarette Smoke Impairs Bacterial Phagocytosis in Macrophages by Modulating CFTR Dependent Lipid-Rafts

Introduction

First/Second-hand cigarette-smoke (FHS/SHS) exposure weakens immune defenses inducing chronic obstructive pulmonary disease (COPD) but the underlying mechanisms are not fully understood. Hence, we evaluated if SHS induced changes in membrane/lipid-raft (m-/r)-CFTR (cystic fibrosis transmembrane conductance regulator) expression/activity is a potential mechanism for impaired bacterial phagocytosis in COPD.

Methods

RAW264.7 murine macrophages were exposed to freshly prepared CS-extract (CSE) containing culture media and/or Pseudomonas-aeruginosa-PA01-GFP for phagocytosis (fluorescence-microscopy), bacterial survival (colony-forming-units-CFU), and immunoblotting assays. The CFTR-expression/activity and lipid-rafts were modulated by transient-transfection or inhibitors/inducers. Next, mice were exposed to acute/sub-chronic-SHS or room-air (5-days/3-weeks) and infected with PA01-GFP, followed by quantification of bacterial survival by CFU-assay.

Results

We investigated the effect of CSE treatment on RAW264.7 cells infected by PA01-GFP and observed that CSE treatment significantly (p<0.01) inhibits PA01-GFP phagocytosis as compared to the controls. We also verified this in murine model, exposed to acute/sub-chronic-SHS and found significant (p<0.05, p<0.02) increase in bacterial survival in the SHS-exposed lungs as compared to the room-air controls. Next, we examined the effect of impaired CFTR ion-channel-activity on PA01-GFP infection of RAW264.7 cells using CFTR172-inhibitor and found no significant change in phagocytosis. We also similarly evaluated the effect of a CFTR corrector-potentiator compound, VRT-532, and observed no significant rescue of CSE impaired PA01-GFP phagocytosis although it significantly (p<0.05) decreases CSE induced bacterial survival. Moreover, induction of CFTR expression in macrophages significantly (p<0.03) improves CSE impaired PA01-GFP phagocytosis as compared to the control. Next, we verified the link between m-/r-CFTR expression and phagocytosis using methyl-β-cyclodextran (CD), as it is known to deplete CFTR from membrane lipid-rafts. We observed that CD treatment significantly (p<0.01) inhibits bacterial phagocytosis in RAW264.7 cells and adding CSE further impairs phagocytosis suggesting synergistic effect on CFTR dependent lipid-rafts.

Conclusion

Our data suggest that SHS impairs bacterial phagocytosis by modulating CFTR dependent lipid-rafts.     

The Correlation between Lung Sound Distribution and Pulmonary Function in COPD Patients

Background

Regional lung sound intensity in chronic obstructive pulmonary disease (COPD) patients is influenced by the severity and distribution of emphysema, obstructed peripheral airways, and altered ribcage and diaphragm configurations and movements due to hyperinflation. Changes in the lung sound distribution accompanied by pulmonary function improvements in COPD patients were observed after bronchodilator inhalation. We investigated the association of lung sound distribution with pulmonary functions, and the effects of emphysematous lesions on this association. These studies were designed to acquire the basic knowledge necessary for the application of lung sound analysis in the physiological evaluation of COPD patients.

Methods

Pulmonary function tests and the percentage of upper- and lower-lung sound intensity (quantitative lung data [QLD]) were evaluated in 47 stable male COPD patients (54 - 82 years of age). In 39 patients, computed tomography taken within 6 months of the study was available and analyzed.

Results

The ratio of lower QLD to upper QLD showed significant positive correlations with FEV₁ %predicted (%FEV₁; ρ = 0.45, p<0.005) and MEF₅₀ %predicted (%MEF₅₀; ρ = 0.46, p<0.005). These correlations were not observed in COPD patients with dominant emphysema (% low attenuation area >40%, n = 20) and were stronger in less emphysematous patients (n = 19, %FEV₁; ρ = 0.64, p<0.005, %MEF₅₀; ρ = 0.71, p<0.001).

Conclusions

In COPD patients, the ratio of lower- to upper-lung sound intensities decreased according to the severity of obstructive changes, although emphysematous lesions considerably affected lung sound distribution.     

Higher Risk of Wheeze in Female than Male Smokers. Results from the Swedish GA2LEN Study

Background

Women who smoke have higher risk of lung function impairment, COPD and lung cancer than smoking men. An influence of sex hormones has been demonstrated, but the mechanisms are unclear and the associations often subject to confounding. This was a study of wheeze in relation to smoking and sex with adjustment for important confounders.

Methods

In 2008 the Global Allergy and Asthma European Network (GA²LEN) questionnaire was mailed to 45.000 Swedes (age 16–75 years), and 26.851 (60%) participated. “Any wheeze”: any wheeze during the last 12 months. “Asthmatic wheeze”: wheeze with breathlessness apart from colds.

Results

Any wheeze and asthmatic wheeze was reported by 17.3% and 7.1% of women, vs. 15.8% and 6.1% of men (both p<0.001). Although smoking prevalence was similar in both sexes, men had greater cumulative exposure, 16.2 pack-years vs. 12.8 in women (p<0.001). Most other exposures and characteristics associated with wheeze were significantly overrepresented in men. Adjusted for these potential confounders and pack-years, current smoking was a stronger risk factor for any wheeze in women aged <53 years, adjusted odds ratio (aOR) 1.85 (1.56–2.19) vs. 1.60 (1.30–1.96) in men. Cumulative smoke exposure and current smoking each interacted significantly with female sex, aOR 1.02 per pack-year (p<0.01) and aOR 1.28 (p = 0.04) respectively. Female compared to male current smokers also had greater risk of asthmatic wheeze, aOR 1.53 vs. 1.03, interaction aOR 1.52 (p = 0.02). These interactions were not seen in age ≥53 years.

Discussion

In addition to the increased risk of COPD and lung cancer female, compared to male, smokers are at greater risk of significant wheezing symptoms in younger age. This became clearer after adjustment for important confounders including cumulative smoke exposure. Estrogen has previously been shown to increase the bioactivation of several compounds in tobacco smoke, which may enhance smoke-induced airway inflammation in fertile women.     

The aryl hydrocarbon receptor is a regulator of cigarette smoke induction of the cyclooxygenase and prostaglandin pathways in human lung fibroblasts

Cigarette smoking can lead to chronic lung inflammation and lung cancer. Chronic inflammation, associated with expression of cyclooxygenase-2 (COX-2) and prostaglandins, predisposes to malignancy. We recently demonstrated that human lung fibroblasts are activated by cigarette smoke to express COX-2 and prostaglandin E(2) (PGE(2)). Little is known about the mechanism whereby smoke activates human lung fibroblasts to produce proinflammatory mediators. Herein, we report the central role of the aryl hydrocarbon receptor (AHR) in cigarette smoke extract (CSE)-induced COX-2, microsomal PGE(2) synthase (mPGES), and PGE(2) production in human lung fibroblasts. Western blot analysis revealed that primary strains of human lung fibroblasts express AHR and aryl hydrocarbon nuclear translocator protein, supporting the possibility that smoke activates lung fibroblasts through this pathway. Experiments were subsequently performed to determine whether the AHR was activated by CSE. Immunocytochemistry and EMSA analysis revealed that CSE induced nuclear translocation of the AHR in human lung fibroblasts. CSE decreased protein levels of the AHR, consistent with AHR ligand-induced proteosome-mediated degradation. CSE also induced mPGES-1 and COX-2 protein and increased PGE(2) production. Treatment of human fibroblasts with AHR antagonists in the presence of CSE inhibited AHR nuclear translocation as well as COX-2, mPGES-1, and PGE(2) production. These data indicate that the AHR pathway plays an important role in cigarette smoke-mediated COX-2 and PG production in human lung fibroblasts and may contribute to tobacco-associated inflammation and lung disease.     

Recuperating lung decoction attenuates inflammation and oxidation in cigarette smoke‐induced COPD in rats via activation of ERK and Nrf2 pathways

Oxidative/antioxidative imbalance and chronic inflammation are the main contributors to the pathogenesis of chronic obstructive pulmonary disease (COPD). This study evaluated the effect of recuperating lung decoction (RLD) on inflammation and oxidative stress in rats with COPD induced by cigarette smoke and lipopolysaccharides (LPS). We used intravenous infusion of LPS combined with cigarette smoke exposure as a COPD rat model. We observed that RLD treatment increased the protein level of GSH and the ratio of GSH/GSSG but decreased 8‐OHdG and 4‐HNE in the serum. Furthermore, RLD significantly inhibited the expressions of IL‐1β, IL‐6, TNF‐α, and TGF‐β induced by cigarette smoke exposure, reduced the number of inflammatory cells in the bronchoalveolar lavage fluid, and alleviated the severity of cigarette smoke‐induced emphysema. Mechanistically, RLD treatment prevented disease through downregulation of phosphorylated‐ERK and Nrf2 expression, which regulates the production of proinflammatory cytokines. RLD treatment exerted a dramatic therapeutic effect on COPD. This study revealed a mechanism that RLD functions on the regulation of ERK signalling to inhibit inflammation.     

A Quantitative Proteomic Approach to Identify Significantly Altered Protein Networks in the Serum of Patients with Lymphangioleiomyomatosis (LAM)

Lymphangioleiomyomatosis (LAM) is a rare and progressive cystic lung condition affecting approximately 3.4–7.5/million women, with an average lag time between symptom onset and diagnosis of upwards of 4 years. The aim of this work was to identify altered proteins in LAM serum which may be potential biomarkers of disease. Serum from LAM patient volunteers and healthy control volunteers were pooled and analysis carried out using quantitative 4-plex iTRAQ technology. Differentially expressed proteins were validated using ELISAs and pathway analysis was carried out using Ingenuity Pathway Analysis. Fourteen proteins were differentially expressed in LAM serum compared to control serum (p<0.05). Further screening validated the observed differences in extracellular matrix remodelling proteins including fibronectin (30% decrease in LAM, p = 0.03), von Willebrand Factor (40% reduction in LAM, p = 0.03) and Kallikrein III (25% increase in LAM, p = 0.03). Pathway networks elucidated the relationships between the ECM and cell trafficking in LAM. This study was the first to highlight an imbalance in networks important for remodelling in LAM, providing a set of novel potential biomarkers. These understandings may lead to a new effective treatment for LAM in the future.