Del-1 Plays a Protective Role against COPD Development by Inhibiting Inflammation and Apoptosis.

Neutrophilic inflammation is a prominent feature of chronic obstructive pulmonary disease (COPD). Developmental endothelial locus-1 (Del-1) has been reported to limit excessive neutrophilic inflammation by inhibiting neutrophil adhesion to the vascular endothelial cells. However, the effects of Del-1 in COPD are not known. We investigated the role of Del-1 in the pathogenesis of COPD. Del-1 protein expression was decreased in the lungs of COPD patients, especially in epithelial cells and alveolar macrophages. In contrast to human lung tissue, Del-1 expression was upregulated in lung tissue from mice treated with cigarette smoke extracts (CSE). Overexpression of Del-1 significantly suppressed IL-8 release and apoptosis in CSE-treated epithelial cells. In contrast, knockdown of Del-1 enhanced IL-8 release and apoptosis. In macrophages, overexpression of Del-1 significantly suppressed inflammatory cytokine release, and knockdown of Del-1 enhanced it. This anti-inflammatory effect was mediated by inhibiting the phosphorylation and acetylation of NF-κB p65. Nuclear factor erythroid 2-related factor 2 (Nrf2) activators, such as quercetin, resveratrol, and sulforaphane, increased Del-1 in both cell types. These results suggest that Del-1, mediated by Nrf2, plays a protective role against the pathogenesis of COPD, at least in part through anti-inflammatory and anti-apoptotic effects.

Analysis of PM2.5 inorganic and organic constituents to resolve contributing sources in Seoul, South Korea and Beijing, China and their possible associations with cytokine IL-8.

China and South Korea are the most polluted countries in East Asia due to significant urbanization and extensive industrial activities. As neighboring countries, collaborative management plans to maximize public health in both countries can be helpful in reducing transboundary air pollution. To support such planning, PM2.5 inorganic and organic species were determined in simultaneously collected PM2.5 integrated filters. The resulting data were used as inputs to positive matrix factorization, which identified nine sources at the ambient air monitoring sites in both sites. Secondary nitrate, secondary sulfate/oil combustion, soil, mobile, incinerator, biomass burning, and secondary organic carbon (SOC) were found to be sources at both sampling sites. Industry I and II were only identified in Seoul, whereas combustion and road dust sources were only identified in Beijing. A subset of samples was selected for exposure assessment. The expression levels of IL-8 were significantly higher in Beijing (167.7 pg/mL) than in Seoul (72.7 pg/mL). The associations between the PM2.5 chemical constituents and its contributing sources with PM2.5-induced inflammatory cytokine (interleukin-8, IL-8) levels in human bronchial epithelial cells were investigated. For Seoul, the soil followed by the secondary nitrate and the biomass burning showed increase with IL-8 production. However, for the Beijing, the secondary nitrate exhibited the highest association with IL-8 production and SOC and biomass burning showed modest increase with IL-8. As one of the highest contributing sources in both cities, secondary nitrate showed an association with IL-8 production. The soil source having the strongest association with IL-8 production was found only for Seoul, whereas SOC showed a modest association only for Beijing. This study can provide the scientific basis for identifying the sources to be prioritized for control to provide effective mitigation of particulate air pollution in each city and thereby improve public health.

Machine Learning-Based Proteomics Reveals Ferroptosis in COPD Patient-Derived Airway Epithelial Cells Upon Smoking Exposure.

BACKGROUND: Proteomics and genomics studies have contributed to understanding the pathogenesis of chronic obstructive pulmonary disease (COPD), but previous studies have limitations. Here, using a machine learning (ML) algorithm, we attempted to identify pathways in cultured bronchial epithelial cells of COPD patients that were significantly affected when the cells were exposed to a cigarette smoke extract (CSE). METHODS: Small airway epithelial cells were collected from patients with COPD and those without COPD who underwent bronchoscopy. After expansion through primary cell culture, the cells were treated with or without CSEs, and the proteomics of the cells were analyzed by mass spectrometry. ML-based feature selection was used to determine the most distinctive patterns in the proteomes of COPD and non-COPD cells after exposure to smoke extract. Publicly available single-cell RNA sequencing data from patients with COPD (GSE136831) were used to analyze and validate our findings. RESULTS: Five patients with COPD and five without COPD were enrolled, and 7,953 proteins were detected. Ferroptosis was enriched in both COPD and non-COPD epithelial cells after their exposure to smoke extract. However, the ML-based analysis identified ferroptosis as the most dramatically different response between COPD and non-COPD epithelial cells, adjusted P value = 4.172 × 10-6, showing that epithelial cells from COPD patients are particularly vulnerable to the effects of smoke. Single-cell RNA sequencing data showed that in cells from COPD patients, ferroptosis is enriched in basal, goblet, and club cells in COPD but not in other cell types. CONCLUSION: Our ML-based feature selection from proteomic data reveals ferroptosis to be the most distinctive feature of cultured COPD epithelial cells compared to non-COPD epithelial cells upon exposure to smoke extract.

Downregulation of Lysosome-Associated Membrane Protein-2A Contributes to the Pathogenesis of COPD.

Background: Macroautophagy plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD), but the role of chaperone-mediated autophagy (CMA) has not been investigated. We investigated if and how CMA is involved in the pathogenesis of COPD. Methods: We measured the level of lysosome-associated membrane protein-2A (LAMP-2A), which is a critical component of CMA that functions as a receptor for cytosolic substrate proteins, in total lung tissues and primary human bronchial epithelial cells (HBECs) from healthy never smokers, smokers, and COPD patients. We assessed the effects of LAMP-2A knock-down on cigarette smoke extract (CSE)-induced aging, cell cycle arrest, and apoptosis in BEAS-2B cells and the expression levels of apoptosis hallmarks in primary HBECs and lung tissue sections. Results: We found that the protein levels of LAMP-2A in lung homogenates and primary HBECs from smokers and COPD patients were lower than those from never smokers. In addition, its level in primary HBECs was negatively correlated with years of smoking. CSE caused degradation of LAMP-2A protein via the lysosomal pathway by activating macroautophagy. Knock-down of LAMP-2A markedly enhanced CSE-induced expression of senescence markers such as p16, p21, p27, and p53. G2/M cell cycle arrest, up-regulation of cyclin B1, and apoptosis in BEAS-2B cells. Apoptosis was increased in CSE-treated primary HBECs and in lung tissues from smokers and COPD patients. Conclusion: Cigarette smoke-induced down-regulation of LAMP-2A is involved in acceleration of aging and apoptosis of lung epithelial cells, which might at least partially contribute to COPD pathogenesis.

Cereblon Deficiency Contributes to the Development of Elastase-Induced Emphysema by Enhancing NF-κB Activation.

Cereblon (CRBN) has been shown to play an essential role in regulating inflammatory response and endoplasmic reticulum stress, thus mediating the development of various diseases. However, little is known about the roles of CRBN in chronic obstructive pulmonary disease (COPD) pathogenesis. We found that the protein levels of CRBN in lung homogenates from patients with COPD were lower than those from never smokers and smokers. The CRBN protein level was positively correlated with the forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC). To investigate the role of CRBN in modulating elastase-induced emphysema, we used Crbn knockout (KO) mice. Elastase-induced emphysematous changes were significantly aggravated in Crbn KO mice. Neutrophil infiltration, lung cell injury, and protein leakage into the bronchoalveolar space were more severe in Crbn KO mice than in wild-type (WT) mice. Furthermore, Crbn KO resulted in the elevated release of neutrophilic chemokines and inflammatory cytokines in lung epithelial cells and macrophages. The transcriptional activity of nuclear factor-κB (NF-κB) was significantly increased in Crbn knocked-down cells. In conclusion, Crbn deficiency might be involved in the development of emphysema by enhancing NF-κB activation, suggesting that targeting CRBN might be an effective therapeutic approach for the treatment of COPD.

Prevalence and impact of airway diseases on clinical outcomes in idiopathic pulmonary fibrosis.

BACKGROUND/AIMS: The prevalence and effects of airway diseases, including asthma, eosinophilic bronchitis (EB), chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) have not been thoroughly studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to evaluate the prevalence of airway diseases in patients with IPF and to identify the differences in symptoms based on the presence of airway diseases. METHODS: This single-institution prospective cohort study was conducted from June 2017 to September 2018, at the Seoul National University Hospital. Spirometry with bronchodilator, methacholine bronchial provocation test, induced sputum with eosinophil stain, and exhaled nitric oxide were performed to confirm the presence of airway disease. The modified Medical Research Council (mMRC) dyspnea scale, COPD assessment test (CAT), St. George's Respiratory Questionnaire (SGRQ), EuroQol-5 dimension (EQ-5D) index, and cough-specific quality of life questionnaire (CQLQ) data were collected to assess symptom severity. RESULTS: Total 147 patients with IPF were screened, and 70 patients were analyzed. The prevalence of airway diseases in the participants was as follows: 5.0% had COPD, 1.7% had asthma, 3.3% had ACO, and 1.7% had EB. The mMRC, CAT, SGRQ, EQ-5D, and CQLQ scores did not differ regardless of combined airway disease. After 3 months, the SGRQ (p = 0.028) and CQLQ (p = 0.030) scores were significantly higher in patients with airway disease than in those without. CONCLUSION: The prevalence of airway diseases in patients with IPF is low, but when airway diseases are accompanied by IPF, symptom severity and quality of life may worsen rapidly.

YPL-001 Shows Various Beneficial Effects against Cigarette Smoke Extract-Induced Emphysema Formation: Anti-Inflammatory, Anti-Oxidative, and Anti-Apoptotic Effects.

Inflammation, oxidative stress, and apoptosis are thought to be important causes of chronic obstructive pulmonary disease (COPD). We investigated the effect of YPL-001 (under phase 2a study, ClinicalTrials.gov identifier NCT02272634), a drug derived from Pseudolysimachion rotundum var. subintegrum, on cigarette smoke extract (CSE)-induced inflammation, the anti-oxidative pathway, and apoptosis in human lung epithelial cells and on CSE-induced emphysema in mice. YPL-001 suppressed CSE-induced expression of IL8 mRNA and protein. This was due to the reduction in NF-κB transcriptional activity by YPL-001, which resulted from the blockade of acetylation of the NF-κB subunit p65 (Lys310). Histone deacetylases (HDACs) prevent gene transcription by condensing the DNA structure and affecting NF-κB nuclear binding. YPL-001 alone increased HDAC2 activity and enhanced CSE-induced activation of HDAC2. YPL-001-induced suppression of NF-κB transcriptional activity might be caused by increased HDAC2 activity. YPL-001 increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression via both degradation of its inhibitory protein, Kelch-like ECH-associated protein 1, and an increase in de novo protein synthesis. YPL-001 increased the DNA binding activity of Nrf2. Consequently, YPL-001 upregulated the expression of Nrf2-targeted anti-oxidant genes such as NAD(P)H quinone dehydrogenase 1 and heme oxygenase 1. Moreover, YPL-001 significantly suppressed CSE-induced apoptotic cell death. In vivo study showed that CSE-induced emphysematous changes, neutrophilic inflammation, protein leakage into bronchoalveolar space, and lung cell apoptosis in mice were suppressed by YPL-001 treatment. Taken together, these results suggest that YPL-001 is a good therapeutic candidate for the treatment of COPD by blocking inflammation and apoptosis and activating the anti-oxidative pathway.

Developmental endothelial locus-1 as a potential biomarker for the incidence of acute exacerbation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Despite the high disease burden of chronic obstructive pulmonary disease (COPD) and risk of acute COPD exacerbation, few COPD biomarkers are available. As developmental endothelial locus-1 (DEL-1) has been proposed to possess beneficial effects, including anti-inflammatory effects, we hypothesized that DEL-1 could be a blood biomarker for COPD. OBJECTIVE: To elucidate the role of plasma DEL-1 as a biomarker of COPD in terms of pathogenesis and for predicting acute exacerbation. METHODS: Cigarette smoke extract (CSE) or saline was intratracheally administered to wild-type (WT) and DEL-1 knockout (KO) C57BL/6 mice. Subsequently, lung sections were obtained to quantify the degree of emphysema using the mean linear intercept (MLI). Additionally, plasma DEL-1 levels were compared between COPD and non-COPD participants recruited in ongoing prospective cohorts. Using negative binomial regression analysis, the association between the plasma DEL-1 level and subsequent acute exacerbation risk was evaluated in patients with COPD. RESULTS: In the in vivo study, DEL-1 KO induced emphysema (KO saline vs. WT saline; P = 0.003) and augmented CSE-induced emphysema (KO CSE vs. WT CSE; P < 0.001) in 29 mice. Among 537 participants, patients with COPD presented plasma log (DEL-1) levels lower than non-COPD participants (P = 0.04), especially non-COPD never smokers (P = 0.019). During 1.2 ± 0.3 years, patients with COPD in the lowest quartile of Log(DEL-1) demonstrated an increased risk of subsequent acute exacerbation, compared with those in the highest quartile of Log(DEL-1) (adjusted incidence rate ratio, 3.64; 95% confidence interval, 1.03-12.9). CONCLUSION: Low DEL-1 levels are associated with COPD development and increased risk of subsequent COPD acute exacerbation. DEL-1 can be a useful biomarker in patients with COPD.

Impact of staffing model conversion from a mandatory critical care consultation model to a closed unit model in the medical intensive care unit.

BACKGROUND: The intensive care unit (ICU) staffing model affects clinical outcomes of critically ill patients. However, the benefits of a closed unit model have not been extensively compared to those of a mandatory critical care consultation model. METHODS: This retrospective before-after study included patients admitted to the medical ICU. Anthropometric data, admission reason, Acute Physiology and Chronic Health Evaluation II score, Eastern Cooperative Oncology Group grade, survival status, length of stay (LOS) in the ICU, duration of mechanical ventilator care, and occurrence of ventilator-associated pneumonia (VAP) were recorded. The staffing model of the medical ICU was changed from a mandatory critical care consultation model to a closed unit model in September 2017, and indices before and after the conversion were compared. RESULTS: A total of 1,526 patients were included in the analysis. The mean age was 64.5 years, and 954 (62.5%) patients were men. The mean LOS in the ICU among survivors was shorter in the closed unit model than in the mandatory critical care consultation model by multiple regression analysis (5.5 vs. 6.7 days; p = 0.005). Central venous catheter insertion (38.5% vs. 51.9%; p < 0.001) and VAP (3.5% vs. 8.6%; p < 0.001) were less frequent in the closed unit model group than in the mandatory critical care consultation model group. After adjusting for confounders, the closed unit model group had decreased ICU mortality (adjusted odds ratio 0.65; p < 0.001) and shortened LOS in the ICU compared to the mandatory critical care consultation model group. CONCLUSION: The closed unit model was superior to the mandatory critical care consultation model in terms of ICU mortality and LOS among ICU survivors.

Mortality prediction in chronic obstructive pulmonary disease and obstructive sleep apnea.

BACKGROUND: We aimed to assess mortality in chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), and overlap syndrome, and evaluate which polysomnographic indices-apnea-hypopnea index (AHI) or hypoxemic load measurements-better predict mortality within 10 years. METHODS: Adults with symptoms suggestive of sleep apnea and airway disease who underwent both polysomnography and spirometry plus bronchodilator response tests between 2000 and 2018 were included and divided into four groups according to presence of COPD and moderate-to-severe OSA (AHI ≥15/h). We estimated mortality using a Cox model adjusted for demographic/anthropometric covariates and comorbidities; this was called clinical model. To evaluate prognostic performance, we compared the concordance index (C-index) between clinical model and extended models, which incorporated one of polysomnographic indices-AHI, sleep time spent with SpO2 < 90% (TS90), and mean and lowest SpO2. RESULTS: Among 355 participants, patients with COPD alone (57/355, 16.1%) and COPD-OSA overlap syndrome (37/355, 10.4%) had increased all-cause mortality than those who had neither disease (152/355, 42.8%) (adjusted HR, 2.98 and 3.19, respectively). The C-indices of extended models with TS90 (%) and mean SpO2 were significantly higher than that of clinical model (0.765 vs. 0.737 and 0.756 vs. 0.737, respectively; all P < 0.05); however, the C-index of extended model with AHI was not (0.739 vs. 0.737; P = 0.15). CONCLUSIONS: In this cohort with symptoms of sleep apnea and airway disease, patients with overlap syndrome had increased mortality, but not higher than in those with COPD alone. The measurement of hypoxemic load, not AHI, better predicted mortality.

The impact of organic extracts of seasonal PM2.5 on primary human lung epithelial cells and their chemical characterization.

Lung epithelial cells serve as the first line of defense against various inhaled pollutant particles. To investigate the adverse health effects of organic components of fine particulate matter (PM2.5) collected in Seoul, South Korea, we selected 12 PM2.5 samples from May 2016 to January 2017 and evaluated the effects of organic compounds of PM2.5 on inflammation, cellular aging, and macroautophagy in human lung epithelial cells isolated directly from healthy donors. Organic extracts of PM2.5 specifically induced neutrophilic chemokine and interleukin-8 expression via extracellular signal-regulated kinase activation. Moreover, PM2.5 significantly increased the expression of aging markers (p16, p21, and p27) and activated macroautophagy. Average mass concentrations of organic and elemental carbon had no significant correlations with PM2.5 effects. However, polycyclic aromatic hydrocarbons and n-alkanes were the most relevant components of PM2.5 that correlated with neutrophilic inflammation. Vegetative detritus and residential bituminous coal combustion sources strongly correlated with neutrophilic inflammation, aging, and macroautophagy activation. These data suggest that the chemical composition of PM2.5 is important for determining the adverse health effects of PM2.5. Our study provides encouraging evidence to regulate the harmful components of PM2.5 in Seoul.

LSD1-S112A exacerbates the pathogenesis of CSE/LPS-induced chronic obstructive pulmonary disease in mice.

Lysine-specific demethylase 1 (LSD1) is an epigenetic regulator that modulates the chromatin status, contributing to gene activation or repression. The post-translational modification of LSD1 is critical for the regulation of many of its biological processes. Phosphorylation of serine 112 of LSD1 by protein kinase C alpha (PKCα) is crucial for regulating inflammation, but its physiological significance is not fully understood. This study aimed to investigate the role of Lsd1-S112A, a phosphorylation defective mutant, in the cigarette smoke extract/LPS-induced chronic obstructive pulmonary disease (COPD) model using Lsd1SA/SA mice and to explore the potential mechanism underpinning the development of COPD. We found that Lsd1SA/SA mice exhibited increased susceptibility to CSE/LPS-induced COPD, including high inflammatory cell influx into the bronchoalveolar lavage fluid and airspace enlargement. Additionally, the high gene expression associated with the inflammatory response and oxidative stress was observed in cells and mice containing Lsd1-S112A. Similar results were obtained from the mouse embryonic fibroblasts exposed to a PKCα inhibitor, Go6976. Thus, the lack of LSD1 phosphorylation exacerbates CSE/LPS-induced COPD by elevating inflammation and oxidative stress. [BMB Reports 2021; 54(10): 522-527].

Sleep Duration and Its Associations with Mortality and Quality of Life in Chronic Obstructive Pulmonary Disease: Results from the 2007-2015 KNAHNES.

BACKGROUND: While extreme sleep duration negatively affects mortality and health-related quality of life (HRQOL) in general populations, the relationship remains uncertain in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To evaluate the association between sleep duration and mortality and HRQOL in patients with COPD. METHODS: We analyzed 3,349 participants with COPD enrolled in the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). Participants aged 40 years or older with a smoking history and prebronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.7 were eligible. The participants were categorized as short sleepers (<6 h), 6-8 h, and long sleepers (>8) according to self-reported sleep duration. The outcome variables were all-cause mortality and HRQOL. HRQOL was measured using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.5 years, 386 (11.5%) participants died. In unadjusted Cox regression analysis, short sleepers with COPD had an increased risk of death (hazard ratio, 1.35; 95% confidence interval [CI]: 1.07-1.71). However, this association was not significant after adjusting for sociodemographic factors, BMI, FEV1, and comorbidities. In unadjusted and adjusted multiple linear regression, short sleepers had significantly worse HRQOL. The adjusted means of the EQ-5D index were 0.88 (95% CI: 0.87-0.89) for short sleepers, 0.90 (95% CI: 0.90-0.91) for 6- to 8-h sleepers, and 0.89 (95% CI: 0.87-0.91) for long sleepers (p = 0.01). CONCLUSIONS: In patients with COPD, sleep duration was not associated with all-cause mortality. However, short sleep duration was significantly associated with worse HRQOL.

Cigarette smoke extract-induced downregulation of p300 is responsible for the impaired inflammatory cytokine response of macrophages.

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to infection owing to the impaired immune function of alveolar macrophages. This is presumed to be caused, at least partially, by cigarette smoke (CS), which is a major risk factor for COPD. Although CS has been reported to inhibit Toll-like receptor (TLR) function and phagocytosis in macrophages, the molecular mechanism of CS-mediated impairment of macrophage immune function has not been completely elucidated. We investigated the effects of CS extracts (CSE) on macrophage immune function and its molecular mechanism. We assessed lipopolysaccharide (LPS, TLR4 ligand)-, Pam3CSK4 (TLR2 ligand)-, or CpG-oligodeoxynucleotide (TLR9 ligand)-induced IL-6, TNF-α, and IL-1ß production in macrophages. Upregulation of IL-6, TNF-α, and IL-1ß mRNA and protein by TLR ligands was suppressed on treatment with CSE. However, LPS-induced MAP kinase activation, IκBα degradation, and nuclear translocation of NF-κB were not impeded by CSE. In contrast, CSE significantly suppressed NF-κB transcriptional activity in the nucleus. We found that p300, which acetylates RelA/p65 at lysine 310, and acetyl-p65 (K310) were downregulated upon CSE treatment. Knock-down of p300 suppressed LPS-induced acetylation of NF-κB p65 and production of inflammatory cytokine. To summarize, these results suggest that CSE impair cytokine response by decreasing the expression levels of p300.

Impact of Sleep Duration on Mortality and Quality of Life in Chronic Kidney Disease: Results from the 2007-2015 KNHANES.

INTRODUCTION: In the general population, short and long sleep durations have been associated with adverse health outcomes. However, this association remains unclear in patients with chronic kidney disease (CKD). We examined the relationship of sleep duration to mortality and health-related quality of life (HRQOL) in individuals with CKD. METHODS: A total of 1,783 adults with CKD who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey were analyzed. CKD was defined as an estimated glomerular filtration rate of <60 mL/min per 1.73 m2. Participants were categorized into 3 groups according to self-reported sleep duration: <6 h (short sleepers), 6-8 h, and >8 h (long sleepers). The outcome variables were all-cause mortality and HRQOL. HRQOL was assessed using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.4 years, 481 (27%) deaths occurred. In unadjusted Cox regression analysis, long sleepers with CKD had an increased risk of death (hazard ratio [HR], 1.62; 95% confidence interval [CI]: 1.26-2.09). This significant association remained after adjusting for age, sex, and BMI (HR, 1.36; 95% CI: 1.05-1.75); however, it was lost after adjusting for CKD stage, social and lifestyle factors, and presence of comorbidities (HR, 1.15; 95% CI: 0.89-1.49). Compared with 6- to 8-h sleepers with CKD, long sleepers with CKD had significantly worse HRQOL in multivariable linear regression models. The adjusted means of the EQ-5D index were 0.80 (95% CI: 0.77-0.82) for short sleepers, 0.81 (95% CI: 0.80-0.82) for 6- to 8-h sleepers, and 0.76 (95% CI: 0.73-0.79) for long sleepers (p = 0.01). DISCUSSION/CONCLUSION: Long sleep duration is associated with poor HRQOL in Korean adults with CKD. The weak association between long sleep duration and mortality was attenuated after multivariable adjustment in this study.

Synergistic cycles of protease activity and inflammation via PPARγ degradation in chronic obstructive pulmonary disease.

Inflammation, oxidative stress, and protease-antiprotease imbalance have been suggested to be a pathogenic triad in chronic obstructive pulmonary disease (COPD). However, it is not clear how proteases interact with components of inflammatory pathways. Therefore, this study aimed to evaluate the effect of neutrophil elastase (NE) on lipopolysaccharide (LPS)-induced interleukin 8 (IL-8) production and determine the molecular mechanism in human bronchial epithelial cells (HBECs). Immortalized bronchial epithelial cells and primary HBECs were used to investigate the impact of NE on LPS-induced IL-8 production. The molecular mechanism by which NE modulated LPS-induced IL-8 production was confirmed in elastase-treated C57BL/6 mice and primary HBECs obtained from COPD patients and healthy controls. The results showed that NE treatment synergistically augmented LPS-induced IL-8 production in both immortalized bronchial epithelial cells and primary HBECs. NE partially degraded peroxisome proliferator-activated receptor gamma (PPARγ), which is known to regulate IL-8 production in the nucleus. Treatment with a PPARγ agonist and overexpression of PPARγ reversed the NE-induced synergistic increase in LPS-induced IL-8 production. Moreover, PPARγ levels were lower in lung homogenates and lung epithelial cells from elastase-treated mice than in those from saline-treated mice. In accordance with the findings in mice, PPARγ levels were lower in primary HBECs from COPD patients than in those from healthy never-smokers or healthy smokers. In conclusion, a vicious cycle of mutual augmentation of protease activity and inflammation resulting from PPARγ degradation plays a role in the pathogenesis of COPD.

Cereblon contributes to the development of pulmonary fibrosis via inactivation of adenosine monophosphate-activated protein kinase α1.

Pulmonary fibrosis is a progressive and lethal lung disease characterized by the proliferation and differentiation of lung fibroblasts and the accumulation of extracellular matrices. Since pulmonary fibrosis was reported to be associated with adenosine monophosphate-activated protein kinase (AMPK) activation, which is negatively regulated by cereblon (CRBN), we aimed to determine whether CRBN is involved in the development of pulmonary fibrosis. Therefore, we evaluated the role of CRBN in bleomycin (BLM)-induced pulmonary fibrosis in mice and in transforming growth factor-beta 1 (TGF-ß1)-induced differentiation of human lung fibroblasts. BLM-induced fibrosis and the mRNA expression of collagen and fibronectin were increased in the lung tissues of wild-type (WT) mice; however, they were significantly suppressed in Crbn knockout (KO) mice. While the concentrations of TGF-ß1/2 in bronchoalveolar lavage fluid were increased via BLM treatment, they were similar between BLM-treated WT and Crbn KO mice. Knockdown of CRBN suppressed TGF-ß1-induced activation of small mothers against decapentaplegic 3 (SMAD3), and overexpression of CRBN increased it. TGF-ß1-induced activation of SMAD3 increased α-smooth muscle actin (α-SMA) and collagen levels. CRBN was found to be colocalized with AMPKα1 in lung fibroblasts. CRBN overexpression inactivated AMPKα1. When cells were treated with metformin (an AMPK activator), the CRBN-induced activation of SMAD3 and upregulation of α-SMA and collagen expression were significantly suppressed, suggesting that increased TGF-ß1-induced activation of SMAD3 via CRBN overexpression is associated with AMPKα1 inactivation. Taken together, these data suggest that CRBN is a profibrotic regulator and maybe a potential target for treating lung fibrosis.

Dexmedetomidine versus midazolam for sedation during endobronchial ultrasound-guided transbronchial needle aspiration: A randomised controlled trial.

BACKGROUND: Desaturation is a common complication of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Dexmedetomidine (DEX), a commonly used sedative in intensive care, is associated with less respiratory depression compared with other sedatives. OBJECTIVE: We compared DEX with midazolam (MDZ) when used as a sedative during EBUS-TBNA. DESIGN: A randomised, parallel, double-blinded trial. SETTING: A university-affiliated teaching hospital between June 2014 and July 2015. PATIENTS: A total of 102 patients who underwent EBUS-TBNA were randomly allocated to two groups (48 DEX group, 54 MDZ group). INTERVENTIONS: DEX group received 0.25 to 0.75 µg kg-1 h-1 (start with 0.5 µg kg-1 h-1, modulated in three steps from 0.25 to 0.75 µg kg-1 h-1) of DEX after a loading dose of 0.25 µg kg-1 h-1 for 10 min to maintain a Ramsay Sedation Scale (RSS) of 3 to 5. If the patient was agitated, 1 mg of MDZ bolus was used as a rescue drug. Patients in the MDZ group initially received 0.05 mg kg-1 of MDZ as a bolus. For maintenance and rescue, 1 mg of MDZ bolus was used. MAIN OUTCOME MEASURES: The primary outcome was the presence of oxygen desaturation. Secondary outcomes were level of sedation (Ramsay Sedation Scale score), cough score, sedation and procedure satisfaction score. RESULTS: The baseline characteristics of the patients, duration of EBUS-TBNA procedures and the use of rescue MDZ were not different between the groups. There was no significant difference in desaturation events between the DEX and MDZ groups (56.3 and 68.5%, respectively; P = 0.20). The level of sedation and the sedation satisfaction scores were similar between the two groups. However, cough score was significantly lower in the DEX group (41.9 vs. 53.4; P = 0.02). CONCLUSION: The use of DEX during EBUS-TBNA was not superior to MDZ in terms of oxygen desaturation. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02157818.

Cigarette smoke extract decreased basal and lipopolysaccharide-induced expression of MARCO via degradation of p300.

BACKGROUND AND OBJECTIVE: Alveolar macrophages of patients with COPD display impaired cytokine release and diminished phagocytosis. COPD exacerbations exhibit immune dysfunction towards the respiratory pathogens. CS and CSE were reported to aggravate bacterial infections in COPD patients. METHODS: MARCO is highly expressed in lungs and is involved in pathogen clearance. We investigated the effect of CSE on MARCO expression and its regulatory mechanisms. After relevant siRNA transfection and treatment with CSE and/or LPS, we measured the levels of MARCO by q-RT PCR, immunoblotting and flow cytometry. Immunofluorescence staining and immunoprecipitation were used to evaluate the mechanism. RESULTS: CSE decreased LPS-induced expression of MARCO mRNA and protein. Upregulation of MARCO by LPS was Nrf2-dependent. Nrf2 knockdown significantly suppressed LPS-induced increase in MARCO transcripts. CSE did not block nuclear translocation of Nrf2 in LPS-treated cells, but rather CSE itself strongly accumulated Nrf2 in the nucleus through the degradation of its cytoplasmic inhibitor, KEAP1. However, CSE markedly suppressed LPS-induced Nrf2 acetylation. Histone acetyltransferase p300/CBP directly acetylates Nrf2, which augments promoter-specific DNA binding of Nrf2. Our results reveal CSE-induced polyubiquitinylation and subsequent degradation of p300 via the proteasome. Pretreatment with proteasome inhibitors completely blocked CSE-induced degradation of p300 and suppression of MARCO expression. CONCLUSION: These findings suggest that CSE decreases MARCO expression via the proteasomal degradation of p300 in macrophages, which may be in part responsible for impaired bacterial phagocytosis.