Assessment of wood smoke induced pulmonary toxicity in normal- and chronic bronchitis-like bronchial and alveolar lung mucosa models at air-liquid interface.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has the highest increased risk due to household air pollution arising from biomass fuel burning. However, knowledge on COPD patho-mechanisms is mainly limited to tobacco smoke exposure. In this study, a repeated direct wood smoke (WS) exposure was performed using normal- (bro-ALI) and chronic bronchitis-like bronchial (bro-ALI-CB), and alveolar (alv-ALI) lung mucosa models at air-liquid interface (ALI) to assess broad toxicological end points. METHODS: The bro-ALI and bro-ALI-CB models were developed using human primary bronchial epithelial cells and the alv-ALI model was developed using a representative type-II pneumocyte cell line. The lung models were exposed to WS (10 min/exposure; 5-exposures over 3-days; n = 6-7 independent experiments). Sham exposed samples served as control. WS composition was analyzed following passive sampling. Cytotoxicity, total cellular reactive oxygen species (ROS) and stress responsive NFkB were assessed by flow cytometry. WS exposure induced changes in gene expression were evaluated by RNA-seq (p ≤ 0.01) followed by pathway enrichment analysis. Secreted levels of proinflammatory cytokines were assessed in the basal media. Non-parametric statistical analysis was performed. RESULTS: 147 unique compounds were annotated in WS of which 42 compounds have inhalation toxicity (9 very high). WS exposure resulted in significantly increased ROS in bro-ALI (11.2%) and bro-ALI-CB (25.7%) along with correspondingly increased NFkB levels (bro-ALI: 35.6%; bro-ALI-CB: 18.1%). A total of 1262 (817-up and 445-down), 329 (141-up and 188-down), and 102 (33-up and 69-down) genes were differentially regulated in the WS-exposed bro-ALI, bro-ALI-CB, and alv-ALI models respectively. The enriched pathways included the terms acute phase response, mitochondrial dysfunction, inflammation, oxidative stress, NFkB, ROS, xenobiotic metabolism of AHR, and chronic respiratory disorder. The enrichment of the 'cilium' related genes was predominant in the WS-exposed bro-ALI (180-up and 7-down). The pathways primary ciliary dyskinesia, ciliopathy, and ciliary movement were enriched in both WS-exposed bro-ALI and bro-ALI-CB. Interleukin-6 and tumor necrosis factor-α were reduced (p < 0.05) in WS-exposed bro-ALI and bro-ALI-CB. CONCLUSION: Findings of this study indicate differential response to WS-exposure in different lung regions and in chronic bronchitis, a condition commonly associated with COPD. Further, the data suggests ciliopathy as a candidate pathway in relation to WS-exposure.

Exploring proteomic plasma biomarkers in eosinophilic and neutrophilic asthma.

BACKGROUND: Few biomarkers identify eosinophilic and neutrophilic asthma beyond cell concentrations in blood or sputum. Finding novel biomarkers for asthma endotypes could give insight about disease mechanisms and guide tailored treatment. Our aim was to investigate clinical characteristics and inflammation-related plasma proteins in relation to blood eosinophil and neutrophil concentrations in subjects with and without asthma. METHODS: We included 24-26-year-old subjects (n = 2063) from the Swedish population-based cohort BAMSE. Subjects with asthma (n = 239) and without asthma (n = 1824) were subdivided based on blood eosinophil and neutrophil concentrations (cut-offs 0.3 × 109 /L and 5.0 × 109 /L, respectively). We measured the levels of 92 plasma proteins using Olink Proseek Multiplex Inflammation Panel Assay. Group statistics tests were used to analyse the data, as well as adjusted multiple logistic regression models. RESULTS: Among subjects with asthma, 21.8% had eosinophilic asthma and 20.5% neutrophilic asthma. Eosinophilic asthma, but not neutrophilic asthma, was associated with a distinct clinical phenotype with, for example, higher proportions of eczema and sensitization. Most plasma proteins that associated with high eosinophil and/or neutrophil blood concentrations in subjects with asthma showed similar associations in subjects without asthma. However, out of these proteins, MMP10 levels were associated with eosinophilic asthma and were significantly higher as compared to controls with high eosinophilic concentration, while CCL4 levels associated with high neutrophil concentration only in subjects with asthma. CONCLUSIONS: Eosinophilic asthma was associated with a clear clinical phenotype. With our definitions, we identified MMP10 as a possible plasma biomarker for eosinophilic asthma and CCL4 was linked to neutrophilic asthma. These proteins should be evaluated further in clinical settings and using sputum granulocytes to define the asthma endotypes.

Predictors of electronic cigarette use and its association with respiratory health and obesity in young adulthood in Sweden; findings from the population-based birth cohort BAMSE.

Despite the growing popularity of electronic cigarettes (e-cigarettes) over the last decade, few epidemiological studies have examined the influence on respiratory health in young adulthood. The aim of this study was to identify factors associated with e-cigarette use in young adulthood in Sweden, and to examine associations between e-cigarette use and lung function, respiratory symptoms, and obesity. This cross-sectional study included 3055 young adults from Sweden and used questionnaire and clinical data obtained at age 22-25 years. The prevalence of current e-cigarette use was 3.9% (n = 120). Few participants reported daily (0.4%) or exclusive (0.8%) use of e-cigarettes. In a multivariable adjusted logistic regression model, e-cigarette use was significantly associated with male gender (OR:3.2; 95% CI:1.5-6.7) and cigarette smoking (OR:14.7; 95% CI:5.5-39.0 for daily smoking). Prevalence of cough (15.0% vs. 8.5%) and mucus production (22.3% vs. 14.8%) was significantly higher among e-cigarette users compared to non-users, while no difference in lung function was observed. In addition, the prevalence of overweight/obesity was higher among e-cigarette users compared to non-users (36.7% vs. 22.3% with BMI≥25 kg/m2). In conclusion, cigarette smokers and males used e-cigarette more often compared to females and non-cigarette smokers. Attention should be given to respiratory symptoms among e-cigarette users, although our results may be explained by the concurrent use of conventional cigarettes, as the group of exclusive e-cigarette users were too small to allow firm conclusions.

Increased MUC1 plus a larger quantity and complex size for MUC5AC in the peripheral airway lumen of long-term tobacco smokers.

There is little information on mucins versus potential regulatory factors in the peripheral airway lumen of long-term smokers with (LTS+) and without (LTS-) chronic obstructive pulmonary disease (COPD). We explored these matters in bronchoalveolar lavage (BAL) samples from two study materials, both including LTS+ and LTS- with a very similar historic exposure to tobacco smoke, and healthy non-smokers (HNSs; n=4-20/group). Utilizing slot blot and immunodetection of processed (filtered and centrifuged), as well as unprocessed BAL samples from one of the materials, we compared the quantity and fraction of large complexes of mucins. All LTS displayed an enhanced (median) level of MUC5AC compared with HNS. LTS- displayed a higher level of large MUC5AC complexes than HNS while LTS+ displayed a similar trend. In all LTS, total MUC5AC correlated with blood leukocytes, BAL neutrophil elastase and net gelatinase activity. Large mucin complexes accounted for most MUC5B, without clear group differences. In all LTS, total MUC5B correlated with total MUC5AC and local bacteria. In the same groups, large MUC5B complexes correlated with serum cotinine. MUC1 was increased and correlated with BAL leukocytes in all LTS whereas MUC2 was very low and without clear group differences. Thus, the main part of MUC5AC and MUC5B is present as large complexes in the peripheral airway lumen and historic as well as current exposure to tobacco smoke emerge as potential regulatory factors, regardless of COPD per se. Bacteria, leukocytes and proteinases also constitute potential regulatory factors, of interest for future therapeutic strategies.

Multi-cellular human bronchial models exposed to diesel exhaust particles: assessment of inflammation, oxidative stress and macrophage polarization.

BACKGROUND: Diesel exhaust particles (DEP) are a major component of outdoor air pollution. DEP mediated pulmonary effects are plausibly linked to inflammatory and oxidative stress response in which macrophages (MQ), epithelial cells and their cell-cell interaction plays a crucial role. Therefore, in this study we aimed at studying the cellular crosstalk between airway epithelial cells with MQ and MQ polarization following exposure to aerosolized DEP by assessing inflammation, oxidative stress, and MQ polarization response markers. METHOD: Lung mucosa models including primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI) were co-cultured without (PBEC-ALI) and with MQ (PBEC-ALI/MQ). Cells were exposed to 12.7 µg/cm2 aerosolized DEP using XposeALI®. Control (sham) models were exposed to clean air. Cell viability was assessed. CXCL8 and IL-6 were measured in the basal medium by ELISA. The mRNA expression of inflammatory markers (CXCL8, IL6, TNFα), oxidative stress (NFKB, HMOX1, GPx) and MQ polarization markers (IL10, IL4, IL13, MRC1, MRC2 RETNLA, IL12 andIL23) were measured by qRT-PCR. The surface/mRNA expression of TLR2/TLR4 was detected by FACS and qRT-PCR. RESULTS: In PBEC-ALI exposure to DEP significantly increased the secretion of CXCL8, mRNA expression of inflammatory markers (CXCL8, TNFα) and oxidative stress markers (NFKB, HMOX1, GPx). However, mRNA expressions of these markers (CXCL8, IL6, NFKB, and HMOX1) were reduced in PBEC-ALI/MQ models after DEP exposure. TLR2 and TLR4 mRNA expression increased after DEP exposure in PBEC-ALI. The surface expression of TLR2 and TLR4 on PBEC was significantly reduced in sham-exposed PBEC-ALI/MQ compared to PBEC-ALI. After DEP exposure surface expression of TLR2 was increased on PBEC of PBEC-ALI/MQ, while TLR4 was decreased in both models. DEP exposure resulted in similar expression pattern of TLR2/TLR4 on MQ as in PBEC. In PBEC-ALI/MQ, DEP exposure increased the mRNA expression of anti-inflammatory M2 macrophage markers (IL10, IL4, IL13, MRC1, MRC2). CONCLUSION: The cellular interaction of PBEC with MQ in response to DEP plays a pivotal role for MQ phenotypic alteration towards M2-subtypes, thereby promoting an efficient resolution of the inflammation. Furthermore, this study highlighted the fact that cell-cell interaction using multicellular ALI-models combined with an in vivo-like inhalation exposure system is critical in better mimicking the airway physiology compared with traditional cell culture systems.

Interleukin-26 Production in Human Primary Bronchial Epithelial Cells in Response to Viral Stimulation: Modulation by Th17 cytokines.

Interleukin (IL)-26 is abundant in human airways and this cytokine is involved in the local immune response to a bacterial stimulus in vivo. Specifically, local exposure to the toll-like receptor (TLR) 4 agonist endotoxin does increase IL-26 in human airways and this cytokine potentiates chemotactic responses in human neutrophils. In addition to T-helper (Th) 17 cells, alveolar macrophages can produce IL-26, but it remains unknown whether this cytokine can also be produced in the airway mucosa per se in response to a viral stimulus. Here, we evaluated whether this is the case using primary bronchial epithelial cells from the airway epithelium in vitro, and exploring the signaling mechanisms involved, including the modulatory effects of additional Th17 cytokines. Finally, we assessed IL-26 and its archetype signaling responses in healthy human airways in vivo. We found increased transcription and release of IL-26 protein after stimulation with the viral-related double stranded (ds) RNA polyinosinic-polycytidylic acid (poly-IC) and showed that this IL-26 release involved mitogen-activated protein (MAP) kinases and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The release of IL-26 in response to a viral stimulus was modulated by additional Th17 cytokines. Moreover, there was transcription of IL26 mRNA and expression of the protein in epithelial cells of bronchial brush and tissue biopsies respectively after harvest in vivo. In addition, the extracellular IL-26 protein concentrations in bronchoalveolar lavage (BAL) samples did correlate with increased epithelial cell transcription of an archetype intracellular signaling molecule downstream of the IL-26-receptor complex, STAT1, in the bronchial brush biopsies. Thus, our study suggests that viral stimulation causes the production of IL-26 in lining epithelial cells of human airway structural cells that constitute a critical immune barrier and that this production is modulated by Th17 cytokines.

Pulmonary epithelial cancer cells and their exosomes metabolize myeloid cell-derived leukotriene C4 to leukotriene D4.

Leukotrienes (LTs) play major roles in lung immune responses, and LTD4 is the most potent agonist for cysteinyl LT1, leading to bronchoconstriction and tissue remodeling. Here, we studied LT crosstalk between myeloid cells and pulmonary epithelial cells. Monocytic cells (Mono Mac 6 cell line, primary dendritic cells) and eosinophils produced primarily LTC4 In coincubations of these myeloid cells and epithelial cells, LTD4 became a prominent product. LTC4 released from the myeloid cells was further transformed by the epithelial cells in a transcellular manner. Formation of LTD4 was rapid when catalyzed by γ-glutamyl transpeptidase (GGT)1 in the A549 epithelial lung cancer cell line, but considerably slower when catalyzed by GGT5 in primary bronchial epithelial cells. When A549 cells were cultured in the presence of IL-1ß, GGT1 expression increased about 2-fold. Also exosomes from A549 cells contained GGT1 and augmented LTD4 formation. Serine-borate complex (SBC), an inhibitor of GGT, inhibited conversion of LTC4 to LTD4 Unexpectedly, SBC also upregulated translocation of 5-lipoxygenase (LO) to the nucleus in Mono Mac 6 cells, and 5-LO activity. Our results demonstrate an active role for epithelial cells in biosynthesis of LTD4, which may be of particular relevance in the lung.

Linoleic acid-derived lipid mediators increase in a female-dominated subphenotype of COPD.

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality; however, the role of inflammatory mediators in its pathobiology remains unclear. The aim of this study was to investigate the influence of gender in COPD on lipid mediator levels.Bronchoalveolar lavage fluid (BALF) and serum were obtained from healthy never-smokers, smokers and COPD patients (Global Initiative for Chronic Obstructive Lung Disease stage I-II/A-B) (n=114). 94 lipid mediators derived from the cytochrome-P450, lipoxygenase, and cyclooxygenase pathways were analysed by liquid chromatography-mass spectrometry.Multivariate modelling identified a 9-lipid panel in BALF that classified female smokers with COPD from healthy female smokers (p=6×10(-6)). No differences were observed for the corresponding male population (p=1.0). These findings were replicated in an independent cohort with 92% accuracy (p=0.005). The strongest drivers were the cytochrome P450-derived epoxide products of linoleic acid (leukotoxins) and their corresponding soluble epoxide hydrolase (sEH)-derived products (leukotoxin-diols). These species correlated with lung function (r=0.87; p=0.0009) and mRNA levels of enzymes putatively involved in their biosynthesis (r=0.96; p=0.003). Leukotoxin levels correlated with goblet cell abundance (r=0.72; p=0.028).These findings suggest a mechanism by which goblet cell-associated cytochrome-P450 and sEH activity produce elevated leukotoxin-diol levels, which play a putative role in the clinical manifestations of COPD in a female-dominated disease sub-phenotype.

Comparing human respiratory adverse effects after acute exposure to particulate matter in conventional and particle-reduced swine building environments.

OBJECTIVES: To evaluate innate immunity responses, lung function and symptoms in volunteers acutely exposed to organic dust in swine buildings after installing particle separators aimed to reduce particulate matter exposure. METHODS: 11 healthy participants were exposed in 2 different facilities, with and without installed particle separators, in a cross-over design including 2-3 weeks wash-out between the 2 exposures. Size, distribution and composition of particulate matter and endotoxins in the air were measured. Lung function (spirometry), bronchial responsiveness, symptoms questionnaire and markers of innate immunity in blood and nasal lavage were measured before and after the 3-hour exposures. RESULTS: The number of particles, in particular fine particles sized 0.3-0.5 µm, was reduced in the particle-separated swine building environment (PSE) compared with that in the conventional building (CE). In the PSE, headache (p=0.03) and increased body temperature (p=0.016) were less pronounced than in the CE. The expression of toll-like receptors (TLR)2 and TLR4 on blood monocytes significantly increased (p=0.016 and 0.017, respectively) while cluster of differentiation (CD)14 on neutrophils decreased (p=0.05) after exposure in the CE, yet with no difference between the 2 exposures. Compared with the conventional environment, exposure to the PSE yielded lower interleukin (IL)-6 (p=0.02) and IL-8 (p=0.04) levels in the upper respiratory tract, as assessed by nasal lavage. CONCLUSIONS: Particulate matter and organic dust in the swine building were reduced after installing particle separators, which, in naïve never exposed volunteers, in turn reduced adverse health effects caused by acute exposure in swine buildings compared with exposure to the conventional swine building environment.

Interleukin-26 in antibacterial host defense of human lungs. Effects on neutrophil mobilization.

RATIONALE: The role of the presumed Th17 cytokine IL-26 in antibacterial host defense of the lungs is not known. OBJECTIVES: To characterize the role of IL-26 in antibacterial host defense of human lungs. METHODS: Intrabronchial exposure of healthy volunteers to endotoxin and vehicle was performed during bronchoscopy and bronchoalveolar lavage (BAL) samples were harvested. Intracellular IL-26 was detected using immunocytochemistry and immunocytofluorescence. This IL-26 was also detected using flow cytometry, as was its receptor complex. Cytokines and phosphorylated signal transducer and activator of transcription (STAT) 1 plus STAT3 were quantified using ELISA. Gene expression was analyzed by real-time polymerase chain reaction and neutrophil migration was assessed in vitro. MEASUREMENTS AND MAIN RESULTS: Extracellular IL-26 was detected in BAL samples without prior exposure in vivo and was markedly increased after endotoxin exposure. Alveolar macrophages displayed gene expression for, contained, and released IL-26. Th and cytotoxic T cells also contained IL-26. In the BAL samples, IL-26 concentrations and innate effector cells displayed a correlation. Recombinant IL-26 potentiated neutrophil chemotaxis induced by IL-8 and fMLP but decreased chemokinesis for neutrophils. Myeloperoxidase in conditioned media from neutrophils was decreased. The IL-26 receptor complex was detected in neutrophils and IL-26 decreased phosphorylated STAT3 in these cells. In BAL and bronchial epithelial cells, IL-26 increased gene expression of the IL-26 receptor complex and STAT1 plus STAT3. Finally, IL-26 increased the release of neutrophil-mobilizing cytokines in BAL but not in epithelial cells. CONCLUSIONS: This study implies that alveolar macrophages produce IL-26, which stimulates receptors on neutrophils and focuses their mobilization toward bacteria and accumulated immune cells in human lungs.

Acute effects of acrolein in human volunteers during controlled exposure.

CONTEXT: Acrolein is a reactive aldehyde mainly formed by combustion. The critical effect is considered to be irritation of the eyes and airways; however, the scarce data available make it difficult to assess effect levels. OBJECTIVE: The aim of the study was to determine thresholds for acute irritation for acrolein. METHODS: Nine healthy volunteers of each sex were exposed at six occasions for 2 h at rest to: clean air, 15 ppm ethyl acetate (EA), and 0.05 ppm and 0.1 ppm acrolein with and without EA (15 ppm) to mask the potential influence of odor. Symptoms related to irritation and central nervous system effects were rated on 100-mm Visual Analogue Scales. RESULTS: The ratings of eye irritation were slightly but significantly increased during exposure to acrolein in a dose-dependent manner (p < 0.001, Friedman test) with a median rating of 8 mm (corresponding to "hardly at all") at the 0.1 ppm condition and with no influence from EA. No significant exposure-related effects were found for pulmonary function, or nasal swelling, nor for markers of inflammation and coagulation in blood (IL-6, C-reactive protein, serum amyloid A, fibrinogen, factor VIII, von Willebrand factor, and Clara cell protein) or induced sputum (cell count, differential cell count, IL-6 and IL-8). Blink frequency recorded by electromyography was increased during exposure to 0.1 ppm acrolein alone but not during any of the other five exposure conditions. CONCLUSION: Based on subjective ratings, the present study showed minor eye irritation by exposure to 0.1 ppm acrolein.

Compartment differences of inflammatory activity in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with local and systemic inflammation. The knowledge of interaction and co-variation of the inflammatory responses in different compartments is meagre. METHOD: Healthy controls (n = 23), smokers with (n = 28) and without (n = 29) COPD performed spirometry and dental examinations. Saliva, induced sputum, bronchoalveolar lavage (BAL) fluid and serum were collected. Inflammatory markers were assessed in all compartments using ELISA, flow cytometry and RT-PCR. RESULTS: Negative correlations between lung function and saliva IL-8 and matrix metalloproteinase-9 (MMP-9) were found in smokers with COPD. IL-8 and MMP-9 in saliva correlated positively with periodontal disease as assessed by gingival bleeding in non-smokers.Tumor necrosis factor-α (TNF-α) in saliva, serum and TNF-α mRNA expression on macrophages in BAL-fluid were lower in smokers than in non-smokers. There were positive correlations between soluble TNF-α receptor 1 (sTNFR1) and soluble TNF-α receptor 2 (sTNFR2) in sputum, BAL-fluid and serum in all groups. Sputum interleukin-8 (IL-8) or interleukin-6 (IL-6) was positively correlated with sTNFR1 or sTNFR2 in non-smokers and with sTNFR2 in COPD. CONCLUSION: Saliva which is convenient to collect and analyse, may be suitable for biomarker assessment of disease activity in COPD. An attenuated TNF-α expression was demonstrated by both protein and mRNA analyses in different compartments suggesting that TNF-α response is altered in moderate and severe COPD. Shedding of TNFR1 or TNFR2 is similarly regulated irrespective of airflow limitation.

Adhesion molecules in subjects with COPD and healthy non-smokers: a cross sectional parallel group study.

BACKGROUND: The aim of the study was to investigate how the expression of adhesion molecules changes as neutrophils migrate from the circulation to the lung and if these changes differ between non-smoking subjects and smokers with and without COPD. METHODS: Non-smoking healthy subjects (n=22), smokers without (n=21) and with COPD (n=18) were included. Neutrophils from peripheral blood, sputum and bronchial biopsies were analysed for cell surface expression of adhesion molecules (CD11b, CD62L, CD162). Serum, sputum supernatant and BAL-fluid were analysed for soluble adhesion molecules (ICAM-1, -3, E-selectin, P-selectin, VCAM-1, PECAM-1). RESULTS: Expression of CD11b was increased on circulating neutrophils from smokers with COPD. It was also increased on sputum neutrophils in both smokers groups, but not in non-smokers, as compared to circulating neutrophils.Serum ICAM-1 was higher in the COPD group compared to the other two groups (p<0.05) and PECAM-1 was lower in smokers without COPD than in non-smoking controls and the COPD group (p<0.05). In BAL-fluid ICAM-1 was lower in the COPD group than in the other groups (p<0.05). CONCLUSIONS: Thus, our data strongly support the involvement of a systemic component in COPD and demonstrate that in smokers neutrophils are activated to a greater extent at the point of transition from the circulation into the lungs than in non-smokers.

Heated Tobacco Products: Insights into Composition and Toxicity.

Heated tobacco products (HTPs) are novel products that allow users to inhale nicotine by heating (350 °C) reconstituted tobacco rather than combustion (900 °C) as in conventional cigarettes. HTP sticks containing reconstituted tobacco come in various flavours such as menthol, citrus, etc., like electronic cigarette liquids. Thus, the composition of HTP aerosol will also vary according to the flavouring agents added. Overall, the content of toxic chemicals in HTP aerosol appears to be lower than in cigarette smoke. However, the concentrations of more than twenty harmful and potentially harmful constituents have been reported to be higher in HTP aerosol than in cigarette smoke. Further, several toxic compounds not detected in cigarette smoke are also reported in HTP aerosol. Thus, the risks of HTP use remain unknown. Most of the available data on the composition and health effects of mainstream HTP aerosol exposure are generated by the tobacco industry. Few independent studies have reported short-term pathophysiological effects of HTP use. Currently available HTP toxicity data are mainly on the pulmonary and cardiovascular systems. Moreover, there are no long-term toxicity data and, therefore, the claims of the tobacco industry regarding HTPs as a safer alternative to traditional combustible cigarettes are unsubstantiated. Furthermore, HTP aerosol contains the highly addictive substance nicotine, which is harmful to the adolescent brain, developing foetuses, pregnant women, and also adults. Hence, comprehensive studies addressing the safety profiling related to long-term HTP use are warranted. With this background, the following review summarizes the current state of knowledge on HTP toxicity on four broad lines: composition of mainstream HTP aerosol compared to traditional combustible cigarette smoke, biomarkers of HTP exposure, health effects of HTP exposure, and the harm reduction aspect.

Lipid from electronic cigarette-aerosol both with and without nicotine induced pro-inflammatory macrophage polarization and disrupted phagocytosis.

Clinical cases and experimental evidence revealed that electronic cigarettes (ECIG) induce serious adverse health effects, but underlying mechanisms remain to be fully uncovered. Based on recent exploratory evidence, investigating the effects of ECIG on macrophages can broadly define potential mechanisms by focusing on the effect of ECIG exposure with or without nicotine. Here we investigated the effect of ECIG-aerosol exposure on macrophages (MQ) phenotype, inflammatory response, and function of macrophages.MQ were cultured at air liquid interface and exposed to ECIG-aerosol. Oxidative stress was determined by reactive oxygen species (ROS), heat shock protein 60 (HSP60), glutathione peroxidase (GPx) and heme oxygenase1 (HMOX1). Lipid accumulation and lipid peroxidation were defined by lipid staining and level of malondialdehyde (MDA) respectively. MQ polarization was identified by surface expression markers CD86, CD11C and CD206 as well as pro-inflammatory and anti-inflammatory cytokines in gene and protein level. Phagocytosis of E. coli by MQ was investigated by fluorescence-based phagocytosis assay.ECIG-aerosol exposure in presence or absence of nicotine induced oxidative stress evidenced by ROS, HSP60, GPx, GPx4 and HMOX1 upregulation in MQ. ECIG-aerosol exposure induced accumulation of lipids and the lipid peroxidation product MDA in MQ. Pro-inflammatory MQ (M1) markers CD86 and CD11C but not anti-inflammatory MQ (M2) marker CD206 were upregulated in response to ECIG-aerosol exposure. In addition, ECIG induced pro-inflammatory cytokines IL-1beta and IL-8 in gene level and IL-6, IL-8, and IL-1beta in protein level whereas ECIG exposure downregulated anti-inflammatory cytokine IL-10 in protein level. Phagocytosis activity of MQ was downregulated by ECIG exposure. shRNA mediated lipid scavenger receptor 'CD36' silencing inhibited ECIG-aerosol-induced pro-inflammatory MQ polarization and recovered phagocytic activity of MQ.ECIG exposure alters lung lipid homeostasis and thus induced inflammation by inducing M1 type MQ and impair phagocytic function, which could be a potential cause of ECIG-induced lung inflammation in healthy and inflammatory exacerbation in disease condition.

Assessing tobacco use in Swedish young adults from self-report and urinary cotinine: a validation study using the BAMSE birth cohort.

OBJECTIVES: Studies on health effects of tobacco often rely on self-reported exposure data, which is subjective and can lead to misclassification. The aim of this study was to describe the prevalence of cigarette smoking, snus and e-cigarette use, as well as to validate self-reported tobacco use among young adults in Sweden. METHOD: Participants of a population-based Swedish cohort (n=3052), aged 22-25 years, assessed their tobacco use in a web questionnaire. Urinary cotinine was analysed in a subsample of the study population (n=998). The agreement between self-reported tobacco use and urinary cotinine was assessed using Cohen's Kappa coefficient (κ) at a cut-off level of 50 ng/mL. RESULTS: Patterns of tobacco use differed between men and women. Among men, 20.0% reported daily snus use, 5.8% daily cigarette smoking and 5.6% any e-cigarette use. In contrast, 3.2% of the women reported daily snus use, 9.0% daily cigarette smoking and 2.4% any e-cigarette use. Among the tobacco use categories, daily snus users had the highest levels of cotinine. Of reported non-tobacco users, 3.5% had cotinine levels above the cut-off, compared with 68.0% among both occasional cigarette smokers and snus users, 67.5% among all e-cigarette users and 94.7% and 97.8% among daily cigarette smokers and snus users, respectively. Agreement between self-reported tobacco use and urinary cotinine was classified as strong for daily use of cigarettes (κ=0.824) and snus (κ=0.861), while moderate to weak for occasional smoking (κ=0.618), occasional snus use (κ=0.573) and any e-cigarette use (κ=0.576). CONCLUSIONS: We found high validity of self-reported tobacco use in our study population, particularly for daily tobacco use. Further, we found that daily snus users were exposed to high levels of cotinine. Together with previous findings, our results indicate good validity of self-reported tobacco use among young adults.

Comparable Response Following Exposure to Biodiesel and Diesel Exhaust Particles in Advanced Multicellular Human Lung Models.

Biodiesel is considered to be a sustainable alternative for fossil fuels such as petroleum-based diesel. However, we still lack knowledge about the impact of biodiesel emissions on humans, as airways and lungs are the primary target organs of inhaled toxicants. This study investigated the effect of exhaust particles from well-characterized rapeseed methyl ester (RME) biodiesel exhaust particles (BDEP) and petro-diesel exhaust particles (DEP) on primary bronchial epithelial cells (PBEC) and macrophages (MQ). The advanced multicellular physiologically relevant bronchial mucosa models were developed using human primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI) in the presence or absence of THP-1 cell-derived macrophages (MQ). The experimental set-up used for BDEP and DEP exposures (18 µg/cm2 and 36 µg/cm2) as well as the corresponding control exposures were PBEC-ALI, MQ-ALI, and PBEC co-cultured with MQ (PBEC-ALI/MQ). Following exposure to both BDEP and DEP, reactive oxygen species as well as the stress protein heat shock protein 60 were upregulated in PBEC-ALI and MQ-ALI. Expression of both pro-inflammatory (M1: CD86) and repair (M2: CD206) macrophage polarization markers was increased in MQ-ALI after both BDEP and DEP exposures. Phagocytosis activity of MQ and the phagocytosis receptors CD35 and CD64 were downregulated, whereas CD36 was upregulated in MQ-ALI. Increased transcript and secreted protein levels of CXCL8, as well as IL-6 and TNF-α, were detected following both BDEP and DEP exposure at both doses in PBEC-ALI. Furthermore, the cyclooxygenase-2 (COX-2) pathway, COX-2-mediated histone phosphorylation and DNA damage were all increased in PBEC-ALI following exposure to both doses of BDEP and DEP. Valdecoxib, a COX-2 inhibitor, reduced the level of prostaglandin E2, histone phosphorylation, and DNA damage in PBEC-ALI following exposure to both concentrations of BDEP and DEP. Using physiologically relevant multicellular human lung mucosa models with human primary bronchial epithelial cells and macrophages, we found BDEP and DEP to induce comparable levels of oxidative stress, inflammatory response, and impairment of phagocytosis. The use of a renewable carbon-neutral biodiesel fuel does not appear to be more favorable than conventional petroleum-based alternative, as regards of its potential for adverse health effects.

Increased neutrophil migration in smokers with or without chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: The number of airway neutrophils is increased in chronic obstructive pulmonary disease (COPD), and this may have a central pathophysiological role in the disease. In addition, activation of neutrophils increases their migration into sites of injury. We hypothesize that circulating neutrophils are activated in smokers. METHODS: Peripheral blood neutrophils were isolated from healthy non-smokers (n = 15), and smokers with (n = 15) or without COPD (n = 15), who were matched with regard to cumulative tobacco exposure, and chemotactic responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP), interleukin-8 (IL-8, CXCL8) and leukotriene B(4) (LTB(4)) were assessed using the ChemoTx System (Neuro Probe Inc., Gaithersburg, MD, USA). Serum tumour necrosis factor-α (TNF-α) concentrations were measured by ELISA. Surface expression of the neutrophil activation marker, CD11b, was measured by flow cytometry. RESULTS: The chemotactic response to CXCL8 was increased in smokers with or without COPD (P < 0.05). Migration towards LTB(4) was increased in smokers without COPD compared with non-smokers (P < 0.05), whereas there was no difference in fMLP-induced chemotaxis between the groups. There was a correlation between serum TNF-α levels and migration induced by IL-8 (Rho = 0.442; P = 0.038) and LTB(4) (Rho = 0.428; P = 0.044) in the smokers. Furthermore, there was a tendency towards higher CD11b expression in the COPD group (P = 0.057). CONCLUSIONS: Chemotaxis of circulating neutrophils towards CXCL8, and partly towards LTB(4), is increased in smokers, indicating a systemic influence of smoking on cell activation, irrespective of the presence of airflow limitation. The relationship between TNF-α and chemotactic response suggests that TNF-α is involved in neutrophil activation, resulting in enhanced migration.

Biomarkers, Clinical Course, and Individual Needs in COPD Patients in Primary Care: The Study Protocol of the Stockholm COPD Inflammation Cohort (SCOPIC).

Background: To facilitate effective personalized medicine, primary health care needs better methods of assessing and monitoring chronic obstructive pulmonary disease (COPD). Aim: This cohort study aims to investigate how biomarkers relate to clinical characteristics and COPD patients' subjective needs over time. Methods: Patients (n=750) in different COPD severity according to the GOLD criteria and age- and sex-matched controls (n=750) will be recruited over a period of 5 years from 15 primary health care centers in Region Stockholm, Sweden, and followed for 10 years in the first instance. Data on patients' subjective needs will be collected via telephone/email, data on clinical/physiological variables (eg, symptoms, exacerbations, comorbidities, medications, smoking habits, lung function) from existing databases that are based on medical records, and data on biomarkers via repeated blood sampling. Quantitative and qualitative methods will be used. Initial results are expected after 2 years (feasibility test), and a larger body of evidence after 5 years. Discussion: The study is expected to provide definitive and clinically useful scientific evidence about how biomarkers relate to clinical variables and patients' subjective needs. This new evidence will facilitate accurate, and personalized COPD management by the use of valid biomarkers. It will provide useful tools for primary care professionals and may facilitate optimal self-management.

Lung function in young adulthood: differences between males and females with asthma.

Background: There are phenotypic differences in asthma in males and females. Differences in lung function between the sexes at the peak lung function level in young adulthood are so far not directly addressed. The aim of the present study was to assess lung function in early adulthood in males and females depending on asthma onset and remission. Methods: Participants were included from the population-based birth cohort BAMSE and classified as having: never asthma, childhood asthma in remission, adolescent onset asthma or persistent asthma. Pre- and post-bronchodilator lung function (in Z-score) and lung clearance index (LCI) were measured at age 24 years. Lung function was compared stratified for sex between the never asthma and asthma groups univariately and in multiple linear regression analyses adjusted for maternal and paternal asthma, maternal smoking during pregnancy, secondary smoking, daily smoking, early respiratory syncytial virus infection, traffic pollution, childhood allergic sensitisation, and body mass index at age 24 years. Results: All asthma phenotypes were associated with a lower forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) post-bronchodilation at 24 years. This was most pronounced in males with persistent asthma compared to males with never asthma (regression coefficient: -0.503; 95% CI: -0.708- -0.298). Childhood asthma (in remission or persistent) was associated with a lower FEV1. After adjustment, the associations remained significant for males. For females, the significant associations with lower FEV1 and FEV1/FVC remained only for subjects with asthma in remission. Persistent asthma was associated with higher LCI in females. Conclusions: In females, in contrast to males, the association between asthma and lower lung function was attenuated after adjustment for known risk factors.