COPD and the response of the lung to tobacco smoke exposure

Differential proteins from EVs identification based on tandem mass tags analysis and effect of Treg-derived EVs on T-lymphocytes in COPD patients

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a widespread respiratory disease. This study examines extracellular vesicles (EVs) and proteins contained in EVs in COPD.

METHODS

Blood samples were collected from 40 COPD patients and 10 health controls. Cytokines including IFN-γ, TNF-α, IL-1β, IL-6, IL-8, and IL-17, were measured by ELISA. Small EVs samples were extracted from plasma and identified by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blot. Protein components contained in EVs were analyzed by Tandem Mass Tags (TMT) to identify differential proteins. Treg-derived EV was extracted and added to isolated CD8+, Treg, and Th17 subsets to assess its effect on T-lymphocytes.

RESULTS

ELISA revealed higher levels of all cytokines and flow cytometry suggested a higher proportion of Treg and Th17 cells in COPD patients. After identification, TMT analysis identified 207 unique protein components, including five potential COPD biomarkers: BTRC, TRIM28, CD209, NCOA3, and SSR3. Flow cytometry revealed that Treg-derived EVs inhibited differentiation into CD8+, CD4+, and Th17 cells.

CONCLUSION

The study shows that cytokines, T-lymphocyte subsets differences in COPD and Treg-derived EVs influence T-lymphocyte differentiation. Identified biomarkers may assist in understanding COPD pathogenesis, prognosis, and therapy. The study contributes to COPD biomarker research.

Baicalin Relieves Airway Inflammation in COPD by Inhibiting miR-125a

To investigate the effects of Baicalin on the apoptosis of human bronchial epithelial cells (16HBE) induced by cigarette smoke extract (CSE) and the release of inflammatory factors, and to clarify its possible mechanism. CSE was used to treat 16HBE cells and construct COPD cell model. The activity of 16HBE cells was detected by CCK-8 and BrdU. Real-time fluorescence quantitative PCR (RT-QPCR) was used to detect the expression level of miR-125a in each group of 16HBE cells. At the same time, the levels of 16HBE inflammatory cytokines IL-1β, IL-8, IL-6, and TNF-α were detected. The apoptosis rate of 16HBE cells in each group was detected by TUNEL. Compared with the control group, the proliferation of 16HBE cells in CSE group was decreased. Baicalin reversed the effect of 2% CSE on the proliferation of 16HBE cells. Baicalin also reversed the effect of 2% CSE on apoptosis and inflammatory factors in 16HBE cells. miR-125a is highly expressed in COPD, and Baicalin can inhibit the expression of miR-125a. Silencing miR-125a reduces apoptosis and inflammatory response of 16HBE cells in COPD. miR-125a reversed the effects of Baicalin on apoptosis and inflammation of 16HBE cells. Baicalin can reduce CSE-induced apoptosis of human bronchial epithelial cells and release of inflammatory factors, and its mechanism may be related to the inhibition of miR-125a.

CPT1A as a potential therapeutic target for lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) remains a high mortality rate with dramatic lung inflammation and alveolar epithelial cell death. Although fatty acid β-oxidation (FAO) impairment has been implicated in the pathogenesis of ALI, whether Carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme for FAO, plays roles in lipopolysaccharide (LPS)-induced ALI remains unclear. Accordingly, we focused on exploring the effect of CPT1A in the context of ALI and the underlying mechanisms. We found that overexpression of CPT1A (AAV-CPT1A) effectively alleviated lung injury by reduction of lung wet-to-dry ratio, inflammatory cell infiltration, and protein levels in the BALF of ALI mice. Meanwhile, AAV-CPT1A significantly lessened histopathological changes and several cytokines' secretions. In contrast, blocking CPT1A with etomoxir augmented inflammatory responses and lung injury in ALI mice. Furthermore, we found that overexpression of CPT1A with lentivirus reduced the apoptosis rates of alveolar epithelial cells and the expression of apoptosis-related proteins induced by LPS in MLE12 cells, while etomoxir increased the apoptosis of MLE12 cells. Overexpression of CPT1A prevented the drop in bioenergetics, palmitate oxidation, and ATP levels. In conclusion, the results rendered CPT1A worthy of further development into a pharmaceutical drug for the treatment of ALI.

Smoking, dietary factors and major age-related eye disorders: an umbrella review of systematic reviews and meta-analyses

BACKGROUND

There is accumulating evidence of the associations between age-related eye diseases (AREDs) and smoking or dietary factors. We aimed to provide an umbrella review of the published literature pertaining to smoking or dietary intake as risk factors for major AREDs including cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy.

METHODS

We searched for pertinent systematic reviews or meta-analyses in PubMed and Web of Science until 16 April 2022. We reperformed the meta-analysis of each association using random effects models. The heterogeneity and 95% prediction interval were calculated. The presence of small-study effect or excess significance bias was also assessed.

RESULTS

In total, 64 associations from 25 meta-analyses and 41 associations from 10 qualitative systematic reviews were evaluated. There was convincing (class I) evidence for only one association, namely current smoking and cataract. Two factors had highly suggestive (class II) evidence, namely ever smoking associated with cataract and fish consumption associated with AMD. We also found suggestive (class III) evidence for associations between the dietary intake of omega-3 polyunsaturated fatty acid, lutein, zeaxanthin, vitamin C and the risk of cataract.

CONCLUSIONS

Smoking as a risk factor for cataract was the most robust association we identified. We also identified several dietary elements associated with AREDs. Large prospective studies are warranted to further examine the associations discussed in this review.

PROSPERO REGISTRATION NUMBER

CRD42022339082.

Unmasking the Silent Threat: Periodontal Health's Impact on COPD Severity and Hospitalization

OBJECTIVE

This study investigated the relationship between chronic obstructive pulmonary disease (COPD) and periodontitis, focusing on how periodontal health impacts COPD airflow limitation, exacerbations, and hospitalization.

BACKGROUND

Periodontitis, a multifactorial inflammatory disease, is characterized by destruction of tooth-supporting structures, while COPD is a global pulmonary disorder with high mortality.

METHODS

A total of 199 COPD patients aged over 40 years underwent lung function tests (spirometry), 6 min walk test, and St George's Respiratory Questionnaire-COPD (SGRQ-C) to assess lung health. Periodontal indices such as probing depth (PD), clinical attachment loss (CAL), and plaque index (PI) were assessed.

RESULTS

We found a significant negative correlation between periodontal disease severity and lung function (lower FEV1, FVC, and FEV1/FVC ratio) after adjusting for smoking. Likewise, periodontal parameters (PPD, PI, and CAL) exhibited negative correlations with lung function. These periodontal indices were independently associated with airflow limitation severity, exacerbations frequency, and prior-year hospitalization. Linear regression indicated that each unit increase in PPD, PI, and CAL corresponded to estimated increases in GOLD airflow limitation grading (0.288, 0.718, and 0.193, respectively) and number of exacerbations (0.115, 0.041, and 0.109, respectively). In logistic regression, PPD, PI, and CAL adjusted odds ratios (ORs) were estimated to increase by 1.29 (95%CI: 1.03-1.62), 3.04 (95%CI: 1.28-7.2), and 1.26 (95%CI: 1.06-1.49), respectively, for hospitalization in previous year.

CONCLUSION

Periodontitis is associated with COPD airflow limitation, exacerbation, and hospitalization, with PI being the most clinically relevant periodontal factor. Dentists and physicians should monitor and increase awareness among COPD patients to maintain oral hygiene for prevention of periodontal diseases and mitigate its effect on COPD progression.

The Synergistic Effect of Dietary Acid Load Levels and Cigarette Smoking Status on the Risk of Chronic Obstructive Pulmonary Disease (COPD) in Healthy, Middle-Aged Korean Men

We investigated whether cigarette smoking and dietary acid load (DAL) are associated with a risk of chronic obstructive pulmonary disease (COPD) in healthy, middle-aged Korean men. Healthy men without diagnosed chronic disease (aged 40-64 years) from the KNHANES-VI (2013-2015) were included in the analysis (n = 774) and were subdivided by smoking status and DAL levels, as estimated using the quartile of net endogenous acid production (NEAP). The current smokers tended to have a higher risk of COPD than the never-smokers before and after adjustment. When divided by the DAL quartile, the Q4 group tended to have a higher risk of COPD than the Q1 group. Additionally, the current smokers with lower (Q2), modest (Q3), and the highest NEAP scores (Q4) showed risks of COPD that were more than fourfold higher than those of the never-smokers with the lowest NEAP scores (Q1). The ex-smokers with higher NEAP scores (Q3 and Q4) showed risks of COPD that were more than fourfold higher than those of the Q1 group. Interestingly, the risk of COPD was also more than sixfold higher in the never-smokers with the highest NEAP scores compared to that in the Q1 group. The NEAP scores and smoking status synergistically increased the risk of COPD in healthy, middle-aged Korean men. This suggests that DAL levels are an important factor in the prevention and management of COPD.

Cigarette Smoking Contributes to Th1/Th2 Cell Dysfunction via the Cytokine Milieu in Chronic Obstructive Pulmonary Disease

Background

Dysregulation and pyroptosis of T-helper (Th) cells and inflammatory cytokines have been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immune response mechanisms as a consequence of tobacco smoke exposure are not fully understood. We hypothesized that cigarette smoke-induced inflammation could be modulated through the cytokine milieu and T-cell nicotinic acetylcholine receptors (nAChRs).

Methods

The proportions of peripheral blood Th1 and Th2 cells from patients with COPD, smokers without airway obstruction and healthy nonsmokers were analyzed using flow cytometry. The levels of plasma proinflammatory cytokines and their potential association with pulmonary function were also measured. The influence of cigarette smoke extract (CSE) on the conditioned differentiation of T helper cell subsets was further examined in vitro.

Results

Significantly higher Th1 cell and plasma IFN-γ and IL-18 levels but lower levels of Th2 cells were found in the peripheral blood from patients with COPD. The increased plasma levels of IFN-γ and IL-18 were negatively correlated with pulmonary function (FEV1% predicted value). Pyroptosis participates in COPD development probably through the activation of the NLRP3 inflammasome upon exposure to CSE. CSE does not directly induce the differentiation of T helper cells; however, under conditioned medium, CSE promotes Th1 development through α7 nAChR modification, while it does not substantially interfere with Th2 differentiation.

Conclusion

The differences in the cytokine milieu play a key role in the effects of CSE on the immune response in patients with COPD.

Exploring Current Concepts and Challenges in the Identification and Management of Early-Stage COPD

The need to improve health outcomes, as well as disease prognosis, has led clinicians and researchers to propose new ways of identifying COPD in its earliest forms. This initiative is based on the hypothesis that an earlier intervention would have a greater prognostic impact. However, the operational definition of a patient in the initial stages of the disease is complex, and there is still no unanimously accepted definition. GOLD has recently proposed different concepts to identify COPD in its early stages, such as COPD in young people or COPD with mild functional impairment. In addition, GOLD proposes two other concepts, called pre-COPD (symptomatic non-obstructive patients) and PRISm (preserved ratio with impaired spirometry), which aim to identify the patient at risk of developing this chronic airflow obstruction. However, despite the attractiveness of these concepts, none have been taken up universally by the medical community. A universally accepted identification of how to define COPD in its early stages is necessary as a preliminary step in order to design clinical trials to find out the best way to treat these patients. This review deals with these concepts of COPD at the onset of the disease, highlighting their importance and the problems involved in identifying them as therapeutic targets in real clinical practice.

Flavoured and nicotine-containing e-liquids impair homeostatic properties of an alveolar-capillary cell model

Most people consider that electronic cigarettes are safer than tobacco and are marketed as quit-smoking products. The e-liquid, which usually contains propylene glycol (PG) and vegetable glycerin (VG) in different ratios, nicotine and a wide variety of flavours, is heated by a coil and the aerosol droplets are primarily delivered to the alveolar area where nicotine and other molecules cross the alveolar-capillary barrier (ACB). However, e-cigarettes effects on the ACB are not yet established. In our study, a well-characterised in vitro model of the ACB was exposed to PG and VG and to five flavoured e-liquids with and without nicotine. The vehicles, due to their hypertonic properties, modulated the ACB integrity by modifying occludin expression. Below a 10% concentration, the vehicles did not trigger oxidative stress or cell death. Different results were observed between flavoured e-liquids: while red fruits and mint-eucalyptus disrupted ACB integrity, triggered oxidative stress and cell death, blond tobacco had no worse effect compared to the vehicles. However, the addition of nicotine in the latter e-liquid increased oxidative stress and cell death compared to the vehicles. Finally, mint-eucalyptus e-liquid increased some inflammation markers. Our results revealed that e-liquids alter ACB homeostasis, depending on flavour and nicotine presence.

Biological and Genetic Mechanisms of COPD, Its Diagnosis, Treatment, and Relationship with Lung Cancer

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic adult diseases, with significant worldwide morbidity and mortality. Although long-term tobacco smoking is a critical risk factor for this global health problem, its molecular mechanisms remain unclear. Several phenomena are thought to be involved in the evolution of emphysema, including airway inflammation, proteinase/anti-proteinase imbalance, oxidative stress, and genetic/epigenetic modifications. Furthermore, COPD is one main risk for lung cancer (LC), the deadliest form of human tumor; formation and chronic inflammation accompanying COPD can be a potential driver of malignancy maturation (0.8-1.7% of COPD cases develop cancer/per year). Recently, the development of more research based on COPD and lung cancer molecular analysis has provided new light for understanding their pathogenesis, improving the diagnosis and treatments, and elucidating many connections between these diseases. Our review emphasizes the biological factors involved in COPD and lung cancer, the advances in their molecular mechanisms' research, and the state of the art of diagnosis and treatments. This work combines many biological and genetic elements into a single whole and strongly links COPD with lung tumor features.

Influence of smoking status on acute biomarker responses to successive days of arduous military training

INTRODUCTION

Habitual smoking is highly prevalent in military populations despite its association with poorer training outcomes. Smoking imposes challenges on the immune and endocrine systems which could alter how smokers acutely respond to, and recover from, intensive exercise particularly over multiple days of training.

METHODS

Over a two-day period, 35 male British Army recruits (age 22±3 years; mass 76.9±8.0 kg; height 1.78±0.06 m; 15 smokers) completed a 16.1 km loaded march (19.1 kg additional mass) on the first morning and a best-effort 3.2 km 'log race' (carrying a 60 kg log between six and eight people) on the subsequent morning. Blood samples were obtained on waking and immediately postexercise on both days and analysed for C reactive protein (CRP), interleukin 6 (IL-6), testosterone to cortisol ratio and insulin-like growth factor 1 (IGF-1).

RESULTS

Independent of smoking group, the exercise bouts on both days evoked significant increases in IL-6 (p<0.001) and decreases in testosterone to cortisol ratio (p<0.05). CRP concentrations on day 2 were significantly higher than both time points on day 1 (p<0.001), and a 9% decline in IGF-1 occurred over the two-day period, but was not significant (p=0.063). No significant differences were observed between smokers and non-smokers (p>0.05).

CONCLUSIONS

Military-specific tasks elicited inflammatory and endocrine responses, with systemic CRP and IGF-1 indicating that the physiological stress generated during the first training day was still evident on the second day. Despite the well-established impacts of smoking on resting levels of the markers examined, responses to two days of arduous military-specific training did not differ by smoking status.

Cpt1a alleviates cigarette smoke‑induced chronic obstructive pulmonary disease

The current study aimed to determine the expression of carnitine palmitoyltransferase 1A (Cpt1a) in the lung tissue of chronic obstructive pulmonary disease (COPD) patients and its correlation with lung function. An increase in Cpt1a expression improved lung function in patients with COPD by inhibiting apoptosis and the inflammatory response of lung endothelial cells. Lung tissues of 20 patients with COPD and 10 control patients were collected, their Cpt1a expression was determined by western blotting and apoptosis and inflammation were assessed by haematoxylin-eosin staining, TUNEL assay and ELISA. Mice with knockout or overexpression of Cpt1a were constructed by lentivirus in vivo. A COPD model was induced by cigarette smoke and the role of Cpt1a in COPD was determined in vivo and in vitro. Cpt1a expression was positively correlated with lung function and negatively correlated with apoptosis and inflammation. Patients with COPD with higher expression of Cpt1a in lung tissues had improved lung function indices and lung tissue morphology with less apoptosis and decreased inflammatory response. Compared with the control group, COPD mice with Cpt1a knockdown had aggravated lung dysfunction and increased lung inflammation and apoptosis. Overexpression of Cpt1a alleviated lung dysfunction and reduced inflammatory response and apoptosis of lung tissues in COPD mice. Pulmonary microvascular endothelial cells of mice were isolated in vitro and the results were consistent with the findings obtained in vivo. In conclusion, the clinical, in vivo and in vitro data confirmed for the first time that Cpt1a alleviated lung dysfunction of patients with COPD by inhibiting apoptosis of endothelial cells and inflammatory responses.

Interleukin-37 ameliorates cigarette smoke-induced lung inflammation in mice

Cigarette smoking (CS) is the leading cause of chronic obstructive pulmonary disease, and its severity is closely related to lung inflammation. Interleukin (IL)-37 is a newly discovered member of the IL-1 family with anti-inflammatory activity. Our study aimed to elucidate the effect of IL-37 on CS-induced lung inflammation in mice. In this study, mice were exposed to six cigarettes for 1 h three times daily (4 h smoke-free intervals) for 10 consecutive days. Mice were treated intranasally with IL-37-expressing lentivirus and empty lentivirus particles 1 day before the first CS or sham exposure. Mice were sacrificed on day 11 to evaluate the effect of IL-37 on CS-induced pulmonary inflammation in mice. Administering IL-37-expressing lentivirus significantly reduced CS-induced weight loss in mice compared to empty lentivirus controls (P < 0.05). Histological analysis showed that IL-37 significantly alleviated inflammatory cell recruitment, alveolar septum enlargement, alveolar wall attenuation, mucus hypersecretion, and goblet cell metaplasia in mouse lungs (P < 0.001). IL-37 expression also significantly inhibited CS-induced increases in inflammatory cells (including lymphocytes, neutrophils, and macrophages) in mouse lungs (P < 0.05), as well as pro-inflammatory cytokines such as IL-1β, IL-6, IL-17, monocyte chemotactic protein-1 and tumor necrosis factor-α production (P < 0.05). IL-37 also significantly reduced myeloperoxidase activity in mouse serum (P < 0.01) and lung tissues (P < 0.001). Therefore, IL-37 can ameliorate CS-induced pulmonary inflammation in mice and IL-37 may be a potential therapeutic strategy for CS-induced lung inflammatory diseases.

Extracellular vesicles and chronic obstructive pulmonary disease (COPD): a systematic review

Background

Chronic Obstructive Pulmonary Disease (COPD) is a common inflammatory disease of the airways characterized by irreversible airflow limitation, ranking the third highest cause of death worldwide. Extracellular vesicles (EVs) are important intercellular communication mediators released by cells into their extracellular environment with the capacity to transfer biological signals. EVs involved in COPD hold great potential to understand disease pathogenesis and identify important biomarkers. This systematic review aims to examine all available research on EVs in the pathogenesis and diagnosis of COPD to identify existing knowledge and support further research within the field.

Methods

Publications were searched using PubMed and EMBASE with the search terms (Exosomes or extracellular vesicles or microvesicles or microparticles or ectosomes) AND (chronic obstructive pulmonary disease or COPD or emphysema or bronchitis).

Results

Initial search yielded 512 papers of which 142 were manually selected for review and 43 were eligible for analyses. The studies were divided into groups according to the role of EVs in pathogenesis, EV origin and cargo, their role in COPD exacerbations and their diagnostic utility. EVs were found to be involved in the mechanism of pathogenesis of COPD, derived from various cell types, as well as containing modified levels of miRNAs. EVs also varied according to the pathophysiological status of disease, therefore presenting a possible method for COPD diagnosis and progress monitoring.

Conclusion

The current findings show the limited but good quality research looking at the role of EVs in COPD, demonstrating the need for more studies to better define and provide further insight into the functional characteristics of EV in COPD pathogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01984-0.

Quercetin Improves Pulmonary Function and Prevents Emphysema Caused by Exposure to Cigarette Smoke in Male Mice

Chronic obstructive pulmonary disease (COPD) is the major cause of morbidity and mortality worldwide, and cigarette smoke is a key factor in the development of COPD. Thus, the development of effective therapies to prevent the advancement of COPD has become increasingly essential. We hypothesized that quercetin protects lungs in mice exposed to long-term cigarette smoke. Thirty-five C57BL/6 mice were exposed to cigarette smoke (12 cigarettes per day) for 60 days and pretreated with 10 mg/kg/day of quercetin via orogastric gavage. After the experimental protocol, the animals were euthanized and samples were collected for histopathological, antioxidant defense, oxidative stress and inflammatory analysis. The animals exposed to cigarette smoke showed an increase in respiratory rate and hematological parameters, cell influx into the airways, oxidative damage and inflammatory mediators, besides presenting with alterations in the pulmonary histoarchitecture. The animals receiving 10 mg/kg/day of quercetin that were exposed to cigarette smoke presented a reduction in cellular influx, less oxidative damage, reduction in cytokine levels, improvement in the histological pattern and improvement in pulmonary emphysema compared to the group that was only exposed to cigarette smoke. These results suggest that quercetin may be an agent in preventing pulmonary emphysema induced by cigarette smoke.

Forgotten but not gone: Particulate matter as contaminations of mucosal systems

A decade ago, environmental issues, such as air pollution and the contamination of the oceans with microplastic, were prominently communicated in the media. However, these days, political topics, as well as the ongoing COVID-19 pandemic, have clearly taken over. In spite of this shift in focus regarding media representation, researchers have made progress in evaluating the possible health risks associated with particulate contaminations present in water and air. In this review article, we summarize recent efforts that establish a clear link between the increasing occurrence of certain pathological conditions and the exposure of humans (or animals) to airborne or waterborne particulate matter. First, we give an overview of the physiological functions mucus has to fulfill in humans and animals, and we discuss different sources of particulate matter. We then highlight parameters that govern particle toxicity and summarize our current knowledge of how an exposure to particulate matter can be related to dysfunctions of mucosal systems. Last, we outline how biophysical tools and methods can help researchers to obtain a better understanding of how particulate matter may affect human health. As we discuss here, recent research has made it quite clear that the structure and functions of those mucosal systems are sensitive toward particulate contaminations. Yet, our mechanistic understanding of how (and which) nano- and microparticles can compromise human health via interacting with mucosal barriers is far from complete.

Factors Influencing the Length of Hospital Stay Among Patients with Chronic Obstructive Pulmonary Disease (COPD) in Macao Population: A Retrospective Study of Inpatient Health Record

Purpose

This study aims to identify the effects of patient and clinical therapy factors on the length of hospital stay (LOS) for admission due to chronic obstructive pulmonary disease (COPD) in Macao.

Patients and Methods

Health record of patients with COPD admitted to Kiang Wu Hospital from January 2017 to December 2019 was retrospectively analyzed. Demographic information, blood test results, clinical therapies, and LOS were described and analyzed by multivariable regression.

Results

A total of 1116 admissions were included with the average LOS being 12.28 (±9.23) days. Among them, 735 (66.6%) were male with mean age 79.42 (±10.35) years old, 697 were current or previous smokers (62.5%), and 360 (32.2%) had 3 or more comorbidities. During hospitalization, the most common treatments received were oxygen therapy (n=991,88.8%), antibiotics (n=828,74.2%), and systemic steroids (n=596,53.4%); only 120 (10.8%) had pulmonary rehabilitation (PR) and 128 (11.5%) received noninvasive ventilation (NIV). Inhaled medications were used during nearly 95% of hospitalization cases, while 2 and 3 types of inhaled medications were used during 230 (20.6%) and 582 (52.2%) hospitalization cases, respectively. Patient factors including age (B=0.178, 95% CI:0.535–1.072), being female (B=−1.147, 95% CI:-0.138–0.056), being current (B=−0.086, 95% CI:-0.124–0.018) or previous smoker (B=0.072, 95% CI:0.004–0.087), having 1, 2, 3 and over 3 comorbidities (B=0.126, 95% CI:0.034–0.147; B=0.125, 95% CI:0.031–0.144; B=0.116, 95% CI:0.028–0.146, B=0.090, 95% CI:0.021–0.166) and having low hemoglobin level (B=−0.118, 95% CI:-0.629- −0.214) exhibited significant associations with LOS. The use of NIV (B=0.080, 95% CI:0.022–0.138), pulmonary rehabilitation (B=0.269, 95% CI:0.212–0.327), two and three types of inhaled medications (B=0.109, 95% CI:0.003–0.166, B=0.255, 95% CI:0.083–0.237) were significantly associated with longer LOS (P<0.05).

Conclusion

NIV, PR and combined inhaled medications, which are often used for AECOPD, are the main clinical therapies associated with longer LOS in Macao. Smoking cessation, early treatments of comorbidities may be crucial to avoiding AECOPD and reducing LOS and disease burden.

MicroRNAs as Potential Regulators of Immune Response Networks in Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases (CRDs) are an important factor of morbidity and mortality, accounting for approximately 6% of total deaths worldwide. The main CRDs are asthma and chronic obstructive pulmonary disease (COPD). These complex diseases have different triggers including allergens, pollutants, tobacco smoke, and other risk factors. It is important to highlight that although CRDs are incurable, various forms of treatment improve shortness of breath and quality of life. The search for tools that can ensure accurate diagnosis and treatment is crucial. MicroRNAs (miRNAs) are small non-coding RNAs and have been described as promising diagnostic and therapeutic biomarkers for CRDs. They are implicated in multiple processes of asthma and COPD, regulating pathways associated with inflammation, thereby showing that miRNAs are critical regulators of the immune response. Indeed, miRNAs have been found to be deregulated in several biofluids (sputum, bronchoalveolar lavage, and serum) and in both structural lung and immune cells of patients in comparison to healthy subjects, showing their potential role as biomarkers. Also, miRNAs play a part in the development or termination of histopathological changes and comorbidities, revealing the complexity of miRNA regulation and opening up new treatment possibilities. Finally, miRNAs have been proposed as prognostic tools in response to both conventional and biologic treatments for asthma or COPD, and miRNA-based treatment has emerged as a potential approach for clinical intervention in these respiratory diseases; however, this field is still in development. The present review applies a systems biology approach to the understanding of miRNA regulatory networks in asthma and COPD, summarizing their roles in pathophysiology, diagnosis, and treatment.

Probiotic Prato cheese attenuates cigarette smoke-induced injuries in mice

The efficacy of probiotic Prato cheese against the inflammatory and oxidative damage in mice organs induced by cigarette smoke exposure was investigated. Forty C57BL/6 male mice were assigned to four groups: (CS) exposed to cigarette smoke and fed regular chow; (CS + C) exposed to cigarette smoke and fed daily conventional cheese ad libitum; (CS + PC) exposed to cigarette smoke and fed daily probiotic (Lactobacillus casei-01) cheese ad libitum; and a control group (C) exposed to ambient smoke-free air and fed regular chow. Bronchoalveolar lavage (BAL), blood, gut and liver homogenates were used for biochemical assays. The (CS + PC) group exhibited fewer BAL leukocytes, reactive oxygen species (ROS), and BAL and gut lipid peroxidation than the (CS) and (CS + C) groups, which had findings similar to the (C) group. Probiotic cheese consumption did not change the red blood cell count, but lower lactate dehydrogenase (LDH) levels in plasma, inducible nitric oxide synthase (iNOS) and peroxynitrite expression were observed compared to the (CS) and (CS + C) groups, with findings similar to the (C) group. These results suggest that probiotic Prato cheese consumption reduced oxidative stress in the lungs, gut, and liver.

Nix/BNIP3L-dependent mitophagy accounts for airway epithelial cell injury induced by cigarette smoke

Cigarette smoke-induced airway epithelial cell mitophagy is an important mechanism in the pathogenesis of chronic obstructive pulmonary disease (COPD). Mitochondrial protein Nix (also known as BNIP3L) is a selective autophagy receptor and participates in several human diseases. However, little is known about the role of Nix in airway epithelial cell injury during the development of COPD. The aim of the present study is to investigate the effects of Nix on mitophagy and mitochondrial function in airway epithelial cells exposed to cigarette smoke extract (CSE). Our present study has found that CSE could increase Nix protein expression and induce mitophagy in airway epithelial cells. And Nix siRNA significantly inhibited mitophagy and attenuated mitochondrial dysfunction and cell injury when airway epithelial cells were stimulated with 7.5% CSE. In contrast, Nix overexpression enhanced mitophagy and aggravated mitochondrial dysfunction and cell injury when airway epithelial cells were incubated with 7.5% CSE. These data suggest that Nix-dependent mitophagy promotes airway epithelial cell and mitochondria injury induced by cigarette smoke, and may be involved in the pathogenesis of COPD and other cigarette smoke-associated diseases.

The Th17/Treg Cytokine Imbalance in Chronic Obstructive Pulmonary Disease Exacerbation in an Animal Model of Cigarette Smoke Exposure and Lipopolysaccharide Challenge Association

We proposed an experimental model to verify the Th17/Treg cytokine imbalance in COPD exacerbation. Forty C57BL/6 mice were exposed to room air or cigarette smoke (CS) (12 ± 1 cigarettes, twice a day, 30 min/exposure and 5 days/week) and received saline (50 µl) or lipopolysaccharide (LPS) (1 mg/kg in 50 µl of saline) intratracheal instillations. We analyzed the mean linear intercept, epithelial thickness and inflammatory profiles of the bronchoalveolar lavage fluid and lungs. We evaluated macrophages, neutrophils, CD4+ and CD8+ T cells, Treg cells, and IL-10+ and IL-17+ cells, as well as STAT-3, STAT-5, phospho-STAT3 and phospho-STAT5 levels using immunohistochemistry and IL-17, IL-6, IL-10, INF-γ, CXCL1 and CXCL2 levels using ELISA. The study showed that CS exposure and LPS challenge increased the numbers of neutrophils, macrophages, and CD4+ and CD8+ T cells. Simultaneous exposure to CS/LPS intensified this response and lung parenchymal damage. The densities of Tregs and IL-17+ cells and levels of IL-17 and IL-6 were increased in both LPS groups, while IL-10 level was only increased in the Control/LPS group. The increased numbers of STAT-3, phospho-STAT3, STAT-5 and phospho-STAT5+ cells corroborated the increased numbers of IL-17+ and Treg cells. These findings point to simultaneous challenge with CS and LPS exacerbated the inflammatory response and induced diffuse structural changes in the alveolar parenchyma characterized by an increase in Th17 cytokine release. Although the Treg cell differentiation was observed, the lack of IL-10 expression and the decrease in the density of IL-10+ cells observed in the CS/LPS group suggest that a failure to release this cytokine plays a pivotal role in the exacerbated inflammatory response in this proposed model.

CD147 increases mucus secretion induced by cigarette smoke in COPD

BACKGROUND

CD147 is expressed in many tissues and is involved in many inflammatory diseases. Emerging evidence suggests that the overproduction of mucus is a malignant factor in chronic obstructive pulmonary disease (COPD), which results in severe airway obstruction and repeated airway infections. However, it is still unclear whether CD147 is involved in mucus production in COPD.

METHODS

We determined the expression levels of CD147 and MUC5AC by immunohistochemistry in 42 human lung specimens from three groups (non-smokers without COPD, smokers without COPD and smokers with COPD). For the in vitro experiment, human bronchial epithelial (HBE) cells were treated with cigarette smoke (CS) extract to establish a mucus secretion model; then, CD147 and MUC5AC production were detected by RT-PCR, Western blotting and ELISA. To determine how CD147 is involved in MUC5AC secretion, HBE cells were transfected with small interfering RNA to silence CD147 and pretreated with inhibitors of MMP9 and p38 MAPK, which are common signaling molecules involved in MUC5AC secretion; then, MUC5AC expression was evaluated.

RESULTS

Compared with the expression levels in the non-smokers and smokers without COPD, CD147 and MUC5AC expression levels were higher in the smokers with COPD. In the in vitro experiment, CD147 and MUC5AC expression levels were significantly increased after CS extract incubation compared with those after no treatment. Silencing CD147 by siRNA decreased the CS extract-induced MUC5AC secretion and MMP9 and phosphorylated p38 MAPK production. In addition, inhibiting MMP9 or p38 MAPK decreased the CS extract-induced MUC5AC secretion.

CONCLUSIONS

In lung specimens, CD147 and MUC5AC expression levels were increased in COPD patients. Increased CD147 levels induced by CS extract could stimulate MUC5AC secretion through the MMP9 and p38 MAPK signaling pathway in HBE cells. Therefore, the regulation of CD147 could be a promising target for mucus hypersecretion in COPD.

Cigarette smoke induces ROS mediated autophagy impairment in human corneal epithelial cells

Cigarette smoke is an important indoor air pollutant which has deleterious effects on human health. Continued daily exposure to cigarette smoke has been attributed to the risk factor of ocular surface diseases. However, the mechanisms underlying the ocular surface damage are not fully elucidated. In this study, exposure to cigarette smoke extract (CSE) induced a dose- and time-dependent cytotoxicity in human corneal epithelial (HCE) cells, supported by the observation of reduced cell viability, increased apoptotic cells, elevated intracellular oxidative stress and loss of mitochondrial transmembrane potential. In addition, CSE exposure led to the impairment of proteostasis and autophagy, which resulted in the accumulation of ubiquitinated proteins as aggregates in peri-nuclear spaces. Furthermore, the autophagy inducer, cysteamine was shown to attenuate the CSE induced cell damage, oxidative stress and mitochondrial dysfunction in HCE cells. Moreover, cysteamine inhibited the formation of ubiquitin-positive aggregates around the peri-nuclear region, through regulating the autophagic activity of HCE cells. Similar to in vitro experiments, cigarette smoke induced proteostasis and autophagy impairment in corneal epithelial cells could be rescued by cysteamine in a cigarette smoke-exposed murine model. Therefore, this study may provide first evidence that dysfunction of autophagy contributes to the pathogenesis of ocular surface diseases associated with cigarette smoke exposure. Besides, it also suggests the potential therapeutic value of cysteamine in the prevention and treatment of cigarette smoke induced ocular surface injury. CSE induces cytotoxicity and accumulation of ubiquitinated proteins in HCE cells due to impairment of proteostasis and autophagy, which can be rescued by cysteamine.

Cigarette smoke exposure decreases CFLAR expression in the bronchial epithelium, augmenting susceptibility for lung epithelial cell death and DAMP release

Cigarette smoking is a major risk factor for the inflammatory disease, chronic obstructive pulmonary disease (COPD). The mechanism by which cigarette smoke (CS) induces chronic lung inflammation is still largely unknown. We hypothesize that immunogenic airway epithelial cell death is involved in the initiation of the inflammatory response. We previously identified CFLAR, the gene encoding the cell death regulator protein c-FLIP, to be associated with CS-induced release of damage-associated molecular patterns (DAMPs). Here, we investigated the effect of CS on expression levels of CFLAR in bronchial biopsies from smokers and non-smokers and CFLAR transcript isoform-expression in a dataset of air-liquid interface-differentiated bronchial epithelial cells. Furthermore, CFLAR was down-regulated by siRNA in lung epithelial A549 cells, followed by investigation of the effects on apoptosis, necrosis and DAMP release. CS exposure significantly decreased CFLAR expression in bronchial epithelial cells. Moreover, we observed a shift in relative abundance of the isoforms c-FLIP_S and c-FLIP_L transcripts in bronchial biopsies of current smokers compared to non-smokers, consistent with a shift towards necroptosis. In vitro, down-regulation of CFLAR increased apoptosis at baseline as well as CS extract-induced necrosis and DAMP release. In conclusion, CS exposure decreases CFLAR expression, which might increase susceptibility to immunogenic cell death.

p66Shc Mediates Mitochondrial Dysfunction Dependent on PKC Activation in Airway Epithelial Cells Induced by Cigarette Smoke

Airway epithelial mitochondrial injury plays a critical role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The p66Shc adaptor protein is a newly recognized mediator of mitochondrial dysfunction. However, little is known about the effect of p66Shc on airway epithelial damage in the development of COPD. The aim of the present study is to investigate the roles of p66Shc and its upstream regulators in the mitochondrial injury of airway epithelial cells (Beas-2b) induced by cigarette smoke extract (CSE). Our present study revealed that CSE increased p66Shc expression and its mitochondrial translocation in concentration and time-dependent manners in airway epithelial cells. And p66Shc siRNA significantly attenuated mitochondrial dysfunction and cell injury when airway epithelial cells were stimulated with 7.5% CSE. The total and phosphorylated expression of PKCβ and PKCδ was significantly increased associated with mitochondrial dysfunction and cell injury when airway epithelial cells were exposed to 7.5% CSE. The pretreatments with pharmacological inhibitors of PKCβ and PKCδ could notably suppress p66Shc phosphorylation and its mitochondrial translocation and protect the mitochondria and cells against oxidative damage when airway epithelial cells were incubated with 7.5% CSE. These data suggest that a novel PKCβ/δ-p66Shc signaling pathway may be involved in the pathogenesis of COPD and other oxidative stress-associated pulmonary diseases and provide a potential therapeutic target for these diseases.

Establishment and Evaluation of a Rat Model of Sidestream Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common cause of mortality worldwide. The current lack of an animal model that can be established within a certain time frame and imitate the unique features of the disease is a major limiting factor in its study. The present study established and evaluated an animal model of COPD that represents the early and advanced stage features using short-, middle-, and long-term sidestream cigarette smoke (CS) exposure. One hundred and nine Sprague-Dawley rats were randomly divided into 10 groups for different periods of sidestream CS exposure or no exposure (i.e., normal groups). The rats were exposed to CS from 3R4F cigarettes in an exposure chamber. Histological analysis was performed to determine pathological changes. We also conducted open-field tests, lung function evaluations, and cytokine analysis of the blood serum, bronchoalveolar lavage fluid, and lung tissue. The lung tissue protein levels, blood gases, and were also analyzed. As the CS exposure time increased, the indicators associated with oxidative stress, inflammatory responses, and airway remodeling were greater in the CS exposure groups than in the normal group. At 24 and 36 weeks, the COPD model rats displayed the middle- and advanced-stage features of COPD, respectively. In the 8-week CS exposure group, after the CS exposure was stopped for 4 weeks, inflammatory responses and oxidative responses were ameliorated and lung function exacerbation was reduced compared with the 12-week CS exposure group. Therefore, we established a more adequate rat model of sidestream CS induced COPD, which will have great significance for a better understanding of the pathogenesis of COPD and drug effectiveness evaluation.

Phloretin attenuates mucus hypersecretion and airway inflammation induced by cigarette smoke

BACKGROUNDS

Cigarette smoke (CS)-induced airway mucus hypersecretion and inflammation are the prominent features of chronic obstructive pulmonary disease (COPD). As an anti-inflammatory flavonoid, phloretin was found to be involved in various inflammatory disorders such as sepsis. In this study, the effects of phloretin on CS-induced airway mucin secretion and inflammation were investigated in vivo and in vitro.

METHODS

Phloretin dissolved in 1% DMSO was daily injected intraperitoneally to mice, which were then exposed to CS for four weeks. Mouse lung histologic changes were evaluated, the expression of mucin 5ac (MUC5AC) was measured, bronchoalveolar lavage fluid (BALF) total cells, neutrophils, and macrophages were counted. BALF and lung levels of tumor necrosis factor-alpha and interleukin-1 beta (IL-1β) were quantified. Moreover, the effects of phloretin on cigarette smoke extract (CSE)-induced expression of MUC5AC and IL-1β were investigated in NCI-H292 cells. Then, to explore the potential mechanisms, the signaling molecules including epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK) and P38 were evaluated.

RESULTS

Phloretin pretreatment dramatically suppressed the mucins secretion, inflammatory cell infiltration and inflammatory cytokine release in mouse lungs induced by CS, and it also suppressed CSE-induced expression of MUC5AC and IL-1β in NCI-H292 bronchial epithelial cells. Furthermore, western blot showed that phloretin attenuated the activation of EGFR, ERK and P38 both in vivo and in vitro.

CONCLUSIONS

This study highlights the protective effect of phloretin on CS-related airway mucus hypersecretion and inflammation, where EGFR, ERK and P38 might be involved. These findings suggest that phloretin could be a potential therapeutic drug for COPD.

Microarray analysis of lung long non-coding RNAs in cigarette smoke-exposed mouse model

Several studies have demonstrated the function of long non‑coding RNAs (lncRNAs) in various biological processes, yet their role underlying the susceptibility to cigarette smoke (CS)-induced airway inflammation remains limited. In the present study, we aimed to profile the expression of lncRNAs and mRNAs in CS-exposed mice. C57BL/6 mice were assigned into a single cigarette-smoking machine with or without CS exposure for 4 weeks, followed by lung tissue harvest and RNA isolation. Microarray analysis identified 108 lncRNAs and 119 mRNAs with differential expression levels in CS-exposed mouse lung tissue compared with those in control mice. The expression patterns of several lncRNAs were further confirmed by qRT-PCR. GO and pathway analyses showed that the altered mRNAs were mainly related to the processes of immune response, defense response and cell chemotaxis, cytokine-cytokine receptor interaction and chemokine signaling pathway. Moreover, a single lncRNA may co-expressed with several mRNAs, and so was the mRNA. Our findings uncovered the expression profile of lncRNAs and mRNAs in the lungs of CS-exposed mice, which may offer new insights into pathogenesis of CS-associated airway inflammatory disorders.

Exploring the microbiome in health and disease

The analysis of human microbiome is an exciting and rapidly expanding field of research. In the past decade, the biological relevance of the microbiome for human health has become evident. Microbiome comprises a complex collection of microorganisms, with their genes and metabolites, colonizing different body niches. It is now well known that the microbiome interacts with its host, assisting in the bioconversion of nutrients and detoxification, supporting immunity, protecting against pathogenic microbes, and maintaining health. Remarkable new findings showed that our microbiome not only primarily affects the health and function of the gastrointestinal tract but also has a strong influence on general body health through its close interaction with the nervous system and the lung. Therefore, a perfect and sensitive balanced interaction of microbes with the host is required for a healthy body. In fact, growing evidence suggests that the dynamics and function of the indigenous microbiota can be influenced by many factors, including genetics, diet, age, and toxicological agents like cigarette smoke, environmental contaminants, and drugs. The disruption of this balance, that is called dysbiosis, is associated with a plethora of diseases, including metabolic diseases, inflammatory bowel disease, chronic obstructive pulmonary disease, periodontitis, skin diseases, and neurological disorders. The importance of the host microbiome for the human health has also led to the emergence of novel therapeutic approaches focused on the intentional manipulation of the microbiota, either by restoring missing functions or eliminating harmful roles. In the present review, we outline recent studies devoted to elucidate not only the role of microbiome in health conditions and the possible link with various types of diseases but also the influence of various toxicological factors on the microbial composition and function.

The Association between Smoking and Epiretinal Membrane

We conducted a meta-analysis of analytic and observational studies to evaluate the association between smoking and epiretinal membrane (ERM). The pertinent studies were identified via a literature search using three databases (MEDLINE, Cochrane Library, Embase) and the reference lists of retrieved studies. Cohort, case-control and cross-sectional studies meeting the predefined criteria were included. We extracted the odds ratios (OR) and 95% confidence intervals (CI) from each study. Overall risk estimates were pooled using random-effects models. Subgroup analyses based on several stratified factors were also performed. Two cohort studies and six cross-sectional studies involving 46,837 subjects were included. The pooled effect of all eight studies showed an unexpected significant decreased association between smoking and the occurrence of ERM (OR, 0.72; 95% CI 0.61–0.84; p = 0.29, I² = 17.9%). Subgroup analyses supported this finding, except for the age-unadjusted group (OR, 0.87; 95% CI 0.63–1.22), the ERM classification group (cellophane macular reflex (CMR) OR, 0.93; 95% CI 0.68–1.28; preretinal macular fibrosis (PMF) OR, 0.74; 95% CI 0.41–1.32), the Asian group (OR, 0.75; 95% CI 0.52–1.09) and the past smoker group (OR, 1.02; 95% CI 0.85–1.22). The pooled effects from the current literature suggested a declining association between smoking and ERM, which requires further studies to confirm.

Composition and immunological significance of the upper respiratory tract microbiota

The intestinal microbiota is essential for nutrient acquisition, immune development, and exclusion of invading pathogens. The upper respiratory tract (URT) microbiota is less well studied and does not appear to abide by many of the paradigms of the gastrointestinal tract. Decades of carriage studies in children have demonstrated that microbe–microbe competition and collusion occurs in the URT. Whether colonization with common pathogens (e.g., Staphylococcus aureus and Streptococcus pneumoniae) alters immune development or susceptibility to respiratory conditions is just beginning to be understood. Herein, we discuss the biogeography of the URT microbiota, the succession and evolution of the microbiota through the life course, and discuss the evidence for microbe–microbe interactions in colonization and infection.

Does upregulated host cell receptor expression provide a link between bacterial adhesion and chronic respiratory disease?

Expression of the platelet-activating factor receptor is upregulated in the respiratory epithelium of smokers and chronic obstructive pulmonary disease patients. We have recently determined that increased expression of PAFr correlates with higher levels of adhesion to human bronchial epithelial cells by non-typable Haemophilus influenzae and Streptococcus pneumoniae which are major bacterial pathogens in acute exacerbations of COPD. In addition, we found that a PAFr antagonist decreased the adhesion of both respiratory bacterial pathogens to non-cigarette exposure control levels. This highlights the possibility that epithelial receptors, that are upregulated in response to cigarette smoke, could be targeted to specifically block chronic bacterial infections of the lower respiratory tract. In this commentary, we explore the question of whether adhesion to a temporally-upregulated host receptor is a common event in chronic bacterial disease, and as such, could represent a putative therapeutic target for blocking infection by respiratory and other pathogens.

An antagonist of the platelet-activating factor receptor inhibits adherence of both nontypeable Haemophilus influenzae and Streptococcus pneumoniae to cultured human bronchial epithelial cells exposed to cigarette smoke

BACKGROUND

COPD is emerging as the third largest cause of human mortality worldwide after heart disease and stroke. Tobacco smoking, the primary risk factor for the development of COPD, induces increased expression of platelet-activating factor receptor (PAFr) in the lung epithelium. Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae adhere to PAFr on the luminal surface of human respiratory tract epithelial cells.

OBJECTIVE

To investigate PAFr as a potential drug target for the prevention of infections caused by the main bacterial drivers of acute exacerbations in COPD patients, NTHi and S. pneumoniae.

METHODS

Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE). PAFr expression levels were determined using immunocytochemistry and quantitative polymerase chain reaction. The epithelial cells were challenged with either NTHi or S. pneumoniae labeled with fluorescein isothiocyanate, and bacterial adhesion was measured using immunofluorescence. The effect of a well-evaluated antagonist of PAFr, WEB-2086, on binding of the bacterial pathogens to BEAS-2B cells was then assessed. In silico studies of the tertiary structure of PAFr and the binding pocket for PAF and its antagonist WEB-2086 were undertaken.

RESULTS

PAFr expression by bronchial epithelial cells was upregulated by CSE, and significantly associated with increased bacterial adhesion. WEB-2086 reduced the epithelial adhesion by both NTHi and S. pneumoniae to levels observed for non-CSE-exposed cells. Furthermore, it was nontoxic toward the bronchial epithelial cells. In silico analyses identified a binding pocket for PAF/WEB-2086 in the predicted PAFr structure.

CONCLUSION

WEB-2086 represents an innovative class of candidate drugs for inhibiting PAFr-dependent lung infections caused by the main bacterial drivers of smoking-related COPD.

Prostaglandin E₂ possesses different potencies in inducing Vascular Endothelial Growth Factor and Interleukin-8 production in COPD human lung fibroblasts

We studied the role of PGE2, its biosynthetic enzymes and its receptors, in regulating the functions of lung fibroblasts through the production of Vascular Endothelial Growth Factor (VEGF) and Interleukin-8 (IL-8) in COPD subjects. Lung fibroblasts from Control (C) (n=6), Smoker (HS) (n=6) and COPD patients (n=8) were cultured, and basal PGE2, VEGF, and IL-8 measured in supernatants by ELISA. COX-1/COX-2 and EP receptors expression were assessed by western blot and by RT-PCR. Release of VEGF and IL-8 by human fetal lung fibroblasts (HFL-1; lung, diploid, human) was evaluated under different conditions. PGE2, VEGF, and IL-8 levels, COX-2, EP2, and EP4 protein expression and mRNA were increased in COPD when compared to Controls. Low concentrations of synthetic PGE2 increased the release of VEGF in HFL-1, but higher concentrations were needed to induce the release of IL-8. This effect was mimicked by an EP2 agonist and modulated by an EP4 antagonist. In the airways of COPD subjects, fibroblast-derived PGE2 may regulate angiogenesis and inflammation through the production of VEGF and IL-8 respectively, suggesting that the increase in expression of COX-2, EP2 and EP4 observed in COPD fibroblasts may contribute to steering the role of PGE2 from homeostatic to pro-inflammatory.

Implications of the inflammatory response for the identification of biomarkers of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by both local and systemic inflammation. Because inflammation plays a critical role in the development, course and severity of COPD, inflammatory markers have the potential to improve the current diagnostic and prognostic approaches. Local inflammation in COPD is characterized by an infiltration of inflammatory cells, with an increased expression of cytokines, chemokines, enzymes, growth factors and adhesion molecules. Systemic low-grade inflammation is another common but nonspecific finding in COPD. Exacerbations of COPD are acute clinical events accompanied by an exaggerated inflammatory response. Future investigations in the field of COPD biomarkers should take into account different study designs and biochemical assays, disease course and duration, variations in symptom severity and timing of measurement.

Pulmonary inflammation in foundry workers

OBJECTIVE

To assess whether cumulative dust exposure in foundry work is associated with airway inflammation measured by the analysis of fractionated exhaled nitric oxide (NO) concentration, or by inflammatory markers in exhaled breath condensate or serum.

METHODS

We examined 476 dust-exposed and nonexposed foundry workers, and assessed the individual cumulative exposure to dusts and respirable quartz. Bronchial and alveolar NO production and inflammatory markers in exhaled breath condensate and in serum samples were also analyzed.

RESULTS

After adjusting for pack-years of smoking, increased levels of alveolar NO, serum C-reactive protein, and interleukin-8 were associated with a higher level of cumulative exposure to dust. The referents had higher serum myeloperoxidase levels, bronchial NO output, and 8-isoprostane levels in exhaled breath condensate than in the dust-exposed groups.

CONCLUSIONS

Dust exposure in foundry work may induce both systemic and alveolar inflammation.

Expression of the Oligopeptide Permease Operon of Moraxella catarrhalis Is Regulated by Temperature and Nutrient Availability

Moraxella catarrhalis causes otitis media in children and exacerbations of chronic obstructive pulmonary disease in adults. Together, these two conditions contribute to enormous morbidity and mortality worldwide. The oligopeptide permease (opp) ABC transport system is a nutritional virulence factor important for the utilization of peptides. The substrate binding protein OppA, which binds peptides for uptake, is a potential vaccine antigen, but little was known about the regulation of gene expression. The five opp genes oppB, oppC, oppD, oppF, and oppA are in the same open reading frame. Sequence analysis predicted two promoters, one located upstream of oppB and one within the intergenic region between oppF and oppA. We have characterized the gene cluster as an operon with two functional promoters and show that cold shock at 26°C for ≤ 0.5 h and the presence of a peptide substrate increase gene transcript levels. Additionally, the putative promoter upstream of oppA contributes to the transcription of oppA but is not influenced by the same environmental cues as the promoter upstream of oppB. We conclude that temperature and nutrient availability contribute to the regulation of the Opp system, which is an important nutritional virulence factor in M. catarrhalis.

Inhibitory effects of Cnidium monnieri fruit extract on pulmonary inflammation in mice induced by cigarette smoke condensate and lipopolysaccharide

The aim of this study was to investigate the inhibitory effect of Cnidium monnieri fruit (CM) extracts on pulmonary inflammation induced in mice by cigarette smoke condensate (CSC) and lipopolysaccharide (LPS). Pulmonary inflammation was induced by intratracheal instillation of LPS and CSC five times within 12 days. CM extract was administered orally at a dose of 50 or 200 mg·kg(-1). The number of inflammatory cells in the bronchoalveolar lavage fluid was counted using a fluorescence activated cell sorter. Inflammatory mediator levels were determined by enzyme-linked immunosorbent assay. The administration of LPS and CSC exacerbated airway hyper-responsiveness (AHR) and induced an accumulation of inflammatory cells and mediators, and led to histological changes. However, these responses are modulated by treatment with CM, and the treatment with CM extract produces similar or more extensive results than the treatment with cyclosporin A (CSA). CM extract may have an inhibitory effect on pulmonary inflammation related with chronic obstructive pulmonary disease.

Metabolite Signatures in Hydrophilic Extracts of Mouse Lungs Exposed to Cigarette Smoke Revealed by 1H NMR Metabolomics Investigation

¹H-NMR metabolomics was used to investigate the changes of metabolites in the lungs of mice with and without being exposed to a controlled amount of cigarette smoke. It was found that the concentrations of adenosine derivatives (i.e. ATP, ADP and AMP), inosine and uridine were significantly changed in the lungs of mice exposed to cigarette smoke when compared with controls regardless the mice were obese or of regular weight. The decreased ATP, ADP, AMP and elevated inosine suggested that the deaminases in charge of adenosine derivatives to inosine derivatives conversion would be significantly changed in the lungs of mice exposed to cigarette smoke. Indeed, transcriptional study confirmed that the concentrations of adenosine monophosphate deaminase 2 and adenosine deaminase 2 were significantly changed in the lungs of mice exposed to cigarette smoke. We also found that the ratio of glycerophosphocholine (GPC) to phosphocholine (PC) was significantly increased in the lungs of obese mice compared with those of the regular weight mice. The GPC/PC ratio was further elevated in the lungs of obese group exposed to cigarette smoke.

Clinical and lifestyle-related risk factors for incident multimorbidity: 10-year follow-up of Finnish population-based cohorts 1982-2012

BACKGROUND

Multimorbidity is a huge burden to individuals and societies and more attention should be paid on its risk factors and prevention possibilities. The aim of this study was to investigate which clinical and lifestyle characteristics predict the development of multimorbidity both among initially disease-free people and among people who have diabetes or CVD.

METHODS

Data comprised 25-64 year old, randomly selected men and women (n=32,972) who participated in one of the five national FINRISK surveys between 1982 and 2002 in Finland. The surveys included anthropometric measurements, blood samples and structured questionnaire. Data on incident diagnoses of the five most common chronic diseases during 10 years were received from the national registers on mortality, hospitalizations, and reimbursement rights.

RESULTS

Predisposing factors for multimorbidity among disease-free population were smoking, physical inactivity, and BMI. Among men also systolic blood pressure and low education predicted multimorbidity. Among men with DM at baseline, high blood pressure, physical inactivity, and smoking increased the likelihood of incident multimorbidity. Among women, significant predictors of multimorbidity were high BMI and smoking. Among men and women with CVD, the only baseline factor that was significantly associated with the development of multimorbidity in the multivariate prediction model was low fruit and vegetable consumption.

CONCLUSION

Several modifiable clinical and lifestyle risk factors were found to predict incident multimorbidity. Better recognition and management of these risk factors could potentially have a large impact on the development of multimorbidity, and consequently, premature mortality and costs of care among the aging populations.

Silymarin attenuates airway inflammation induced by cigarette smoke in mice

Cigarette smoke (CS), which increases inflammation and oxidative stress, is a major risk factor for the development of COPD. In this study, we investigated the effects of silymarin, a polyphenolic flavonoid isolated from the seeds and fruits of milk thistle, on CS-induced airway inflammation and oxidative stress in mice and the possible mechanisms. BALB/c mice were exposed to CS for 2 h twice daily, 6 days per week for 4 weeks. Silymarin (25, 50 mg/kg·day) was administered intraperitoneally 1 h before CS exposure. Bronchoalveolar lavage fluid (BALF) was acquired for cell counting and the detection of pro-inflammatory cytokine levels. Lung tissue was collected for histological examination, myeloperoxidase (MPO) activity assay, superoxide dismutase (SOD) activities, and malondialdehyde (MDA) levels. The phosphorylation of ERK and p38 was evaluated by Western blotting. Pretreatment with silymarin significantly attenuated CS-induced thickening of the airway epithelium, peribronchial inflammatory cell infiltration, and lumen obstruction. The numbers of total cells, macrophages, and neutrophils, along with the MPO activity (a marker of neutrophil accumulation) in BALF, were remarkably decreased by silymarin in CS-exposed mice (all p<0.05). In addition, silymarin pretreatment dampened the secretion of TNF-α, IL-1β, and IL-8 in BALF. High-dose silymarin (50 mg/kg·day) administration also prevented CS-induced elevation in MDA levels and decrease in SOD activities (p<0.05). Furthermore, the CS-induced phosphorylation of ERK and p38 was also attenuated by silymarin (p<0.05). These results suggest that silymarin attenuated inflammation and oxidative stress induced by cigarette smoke. The anti-inflammatory effect might partly act through the mitogen-activated protein kinases (MAPK) pathway.

Role of the oligopeptide permease ABC Transporter of Moraxella catarrhalis in nutrient acquisition and persistence in the respiratory tract

Moraxella catarrhalis is a strict human pathogen that causes otitis media in children and exacerbations of chronic obstructive pulmonary disease in adults, resulting in significant worldwide morbidity and mortality. M. catarrhalis has a growth requirement for arginine; thus, acquiring arginine is important for fitness and survival. M. catarrhalis has a putative oligopeptide permease ABC transport operon (opp) consisting of five genes (oppB, oppC, oppD, oppF, and oppA), encoding two permeases, two ATPases, and a substrate binding protein. Thermal shift assays showed that the purified recombinant substrate binding protein OppA binds to peptides 3 to 16 amino acid residues in length regardless of the amino acid composition. A mutant in which the oppBCDFA gene cluster is knocked out showed impaired growth in minimal medium where the only source of arginine came from a peptide 5 to 10 amino acid residues in length. Whether methylated arginine supports growth of M. catarrhalis is important in understanding fitness in the respiratory tract because methylated arginine is abundant in host tissues. No growth of wild-type M. catarrhalis was observed in minimal medium in which arginine was present only in methylated form, indicating that the bacterium requires l-arginine. An oppA knockout mutant showed marked impairment in its capacity to persist in the respiratory tract compared to the wild type in a mouse pulmonary clearance model. We conclude that the Opp system mediates both uptake of peptides and fitness in the respiratory tract.

Identification of nuclear phosphoproteins as novel tobacco markers in mouse lung tissue following short-term exposure to tobacco smoke

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We analyzed nuclear phosphoprotein expression activated by tobacco smoke exposure.

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253 phosphoproteins were identified in 1-day and 7-day exposure groups.

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Of these, 33 were significantly differentially expressed in control and exposed groups.

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Identified proteins were related to inflammation, response to stress and nicotine.

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OSF3 and spectrin β chain were identified as candidate tobacco smoke markers.

Smoking is a risk factor for lung diseases, including chronic obstructive pulmonary disease and lung cancer. However, the molecular mechanisms mediating the progression of these diseases remain unclear. Therefore, we sought to identify signaling pathways activated by tobacco-smoke exposure, by analyzing nuclear phosphoprotein expression using phosphoproteomic analysis of lung tissue from mice exposed to tobacco smoke. Sixteen mice were exposed to tobacco smoke for 1 or 7 days, and the expression of phosphorylated peptides was analyzed by mass spectrometry. A total of 253 phosphoproteins were identified, including FACT complex subunit SPT16 in the 1-day exposure group, keratin type 1 cytoskeletal 18 (K18), and adipocyte fatty acid-binding protein, in the 7-day exposure group, and peroxiredoxin-1 (OSF3) and spectrin β chain brain 1 (SPTBN1), in both groups. Semi-quantitative analysis of the identified phosphoproteins revealed that 33 proteins were significantly differentially expressed between the control and exposed groups. The identified phosphoproteins were classified according to their biological functions. We found that the identified proteins were related to inflammation, regeneration, repair, proliferation, differentiation, morphogenesis, and response to stress and nicotine. In conclusion, we identified proteins, including OSF3 and SPTBN1, as candidate tobacco smoke-exposure markers; our results provide insights into the mechanisms of tobacco smoke-induced diseases.

Epac1 and Epac2 are differentially involved in inflammatory and remodeling processes induced by cigarette smoke

Cigarette smoke (CS) induces inflammatory responses characterized by increase of immune cells and cytokine release. Remodeling processes, such as mucus hypersecretion and extracellular matrix protein production, are also directly or indirectly induced by CS. Recently, we showed that activation of the exchange protein directly activated by cAMP (Epac) attenuates CS extract-induced interleukin (IL)-8 release from cultured airway smooth muscle cells. Using an acute, short-term model of CS exposure, we now studied the role of Epac1, Epac2, and the Epac effector phospholipase-Cε (PLCε) in airway inflammation and remodeling in vivo. Compared to wild-type mice exposed to CS, the number of total inflammatory cells, macrophages, and neutrophils and total IL-6 release was lower in Epac2(-/-) mice, which was also the case for neutrophils and IL-6 in PLCε(-/-) mice. Taken together, Epac2, acting partly via PLCε, but not Epac1, enhances CS-induced airway inflammation in vivo. In total lung homogenates of Epac1(-/-) mice, MUC5AC and matrix remodeling parameters (transforming growth factor-β1, collagen I, and fibronectin) were increased at baseline. Our findings suggest that Epac1 primarily is capable of inhibiting remodeling processes, whereas Epac2 primarily increases inflammatory processes in vivo.