Pathophysiology of Emphysema and Implications

Korean Red Ginseng suppresses emphysematous lesions induced by cigarette smoke condensate through inhibition of macrophage-driven apoptosis pathways

Background

Cigarette smoke is generally accepted as a major contributor to chronic obstructive pulmonary disease (COPD), which is characterized by emphysematous lesions. In this study, we investigated the protective effects of Korean Red Ginseng (KRG) against cigarette smoke condensate (CSC)-induced emphysema.

Methods

Mice were instilled with 50 mg/kg of CSC intranasally once a week for 4 weeks, KRG was administered to the mice once daily for 4 weeks at doses of 100 or 300 mg/kg, and dexamethasone (DEX, positive control) was administered to the mice once daily for 2 weeks at 3 mg/kg.

Results

KRG markedly decreased the macrophage population in bronchoalveolar lavage fluid and reduced emphysematous lesions in the lung tissues. KRG suppressed CSC-induced apoptosis as revealed by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling staining and Caspase 3 immunohistochemistry. Additionally, KRG effectively inhibited CSC-mediated activation of Bcl-2-associated X protein/Caspase 3 signaling, followed by the induction of cell survival signaling, including vascular endothelial growth factor/phosphoinositide 3-kinase/protein kinase B in vivo and in vitro. The DEX group also showed similar improved results in vivo and in vitro.

Conclusion

Taken together, KRG effectively inhibits macrophage-mediated emphysema induced by CSC exposure, possibly via the suppression of pro-apoptotic signaling, which results in cell survival pathway activation. These findings suggest that KRG has therapeutic potential for the prevention of emphysema in COPD patients.

7-Ethoxycoumarin rescued Caenorhabditis elegans from infection of COPD derived clinical isolate Pseudomonas aeruginosa through virulence and biofilm inhibition via targeting Rhl and Pqs quorum sensing systems

Pseudomonas aeruginosa is an ambidextrous Gram-negative contagium with density convoluted network defined quorum sensing, which enables the persistent survival within the host environment, contributing to various lung related diseases including Chronic Obstructive Pulmonary Disease (COPD). It is clear that P. aeruginosa is a powerful, exquisite pathogen that has adopted a variety of virulence properties through quorum sensing (QS) regulated phenomenon and that it dominates both in the development and exacerbations of COPD. Interestingly, 7-Ethoxycoumarin (7-EC), a compound that adequately mimics QS signaling molecule of P. aeruginosa, was introduced as part of the process of developing novel ways to treat the severe exacerbations. The results showed that, introduction of 7-EC significantly decreased exopolysaccharide-mediated biofilm development of strains isolated from COPD sputum, as evidenced by SEM analysis. Furthermore, 7-EC was able to modulate a variety of virulence factors and motility without subjecting planktonic cells to any selection pressure. Bacterial invasion assay revealed the potential activity of the 7-EC in preventing the active entry to A549 cells without causing any damage to the cells and found functionally active in protecting the C. elegans from P. aeruginosa infection and being non-toxic to the worms. Docking analysis was further proved that 7-EC to be the potential anti-QS compound competing specifically with Rhl and Pqs Systems. Therefore, 7-EC in the utilisation against the P. aeruginosa based infections, may open an avenue for the futuristic mechanistic study in chronic respiratory diseases and a initiator for the development of non-antibiotic based antibacterial therapy.

Green tea extract ameliorates macrophage-driven emphysematous lesions in chronic obstructive pulmonary disease induced by cigarette smoke condensate

Chronic obstructive pulmonary disease (COPD) is an important lung disease characterized by complicated symptoms including emphysema. We aimed to explore the mechanisms underlying the protective effect of green tea extract (GTE) on cigarette smoke condensate (CSC)-induced emphysema by demonstrating the reduction of macrophage-induced protease expression through GTE treatment in vivo and in vitro. Mice were intranasally administered 50 mg/kg CSC once a week for 4 weeks, and doses of 100 or 300 mg/kg GTE were administered orally once daily for 4 weeks. GTE significantly reduced macrophage counts in bronchoalveolar lavage fluid and emphysematous lesions in lung tissues in CSC-exposed mice. In addition, GTE suppressed CSC-induced extracellular signal-regulated kinase (ERK)/activator protein (AP)-1 phosphorylation followed by matrix metalloproteinases (MMP)-9 expression as revealed by western blotting, immunohistochemistry, and zymography in CSC-instilled mice. These underlying mechanisms related to reduced protease expression were confirmed in NCI-H292 cells stimulated by CSC. Taken together, GTE effectively inhibits macrophage-driven emphysematous lesions induced by CSC treatment, and these protective effects of GTE are closely related to the ERK/AP-1 signaling pathway, followed by a reduced protease/antiprotease imbalance. These results suggest that GTE can be used as a supplementary agent for the prevention of emphysema progression in COPD patients.

Association Between COPD Symptoms and Psychological Distress Among Farmers

BACKGROUND

Farmers have an increased risk of developing chronic obstructive pulmonary disease (COPD) and psychological distress. The potential role of psychological distress in worsening COPD symptoms has been reported among the general population, but no studies have examined this relationship among farmers with COPD, which is the purpose of this study.

METHODS

This study used the data from the 2017 Behavioral Risk Factor Surveillance System (BRFSS). Farmers reporting both psychological distress and COPD symptoms were included in this study (n = 239). Both unadjusted and adjusted logistic regressions were used to explore the association among psychological distress, age, health status, smoking, and COPD symptoms, with crude and adjusted odds ratio (OR) and 95% CIs reported.

FINDINGS

The unadjusted analysis suggested that COPD symptoms were significantly associated with psychological distress among farmers (OR = 2.05 [1.18, 3.58]). While adjusted models showed the significant association between COPD symptoms and psychological distress among farmers after controlling for smoking, age, and health status (adjusted OR = 2.08 [1.10, 4.01]).

CONCLUSION/IMPLICATIONS FOR PRACTICE

These results suggest that psychological distress is associated with an increased risk of COPD symptoms in farmers, which is consistent with observations from studies in non-farmers. Occupational health professionals need to provide screen for COPD among farmers as well as psychological distress screening and mental health promotion among farmers with COPD.

The associations between the credibility of the tobacco control regulatory body and smoking behavior change among Saudi smokers

INTRODUCTION

Recently, Saudi Arabia has extensively reformed its tobacco control policies and extended its smoking cessation services. A public outrage on social media among smokers was witnessed, especially after the implementation of plain cigarette packaging, which might have discredited the significant efforts of tobacco treatment services and tobacco control policies. However, it is not known how the credibility of the tobacco control regulatory body among Saudi smokers might affect their smoking behavior.

METHODS

Saudi tobacco smokers (n=511) were recruited using a convenience sampling technique. A cross-sectional survey was conducted comprising questions related to the credibility of the tobacco control regulatory body (modified Food and Drug Administration Tobacco Credibility Scale), quit attempts, use of nicotine replacement therapy (NRT), and motivation to change smoking behavior in the future. Logistic and linear regression models were used for the analysis.

RESULTS

The public interest subscale of the credibility of the tobacco control regulatory body, was positively associated with confidence in changing smoking behavior (β=0.204; 95% CI: 0.078-0.713; t=2.449, p=0.015) and readiness to change smoking behavior (β=0.237; 95% CI: 0.127-0.727; t=2.802, p=0.005). Moreover, the subscale of expertise was positively associated with confidence in changing smoking behavior (β=0.190; 95% CI: 0.006-0.697; t=1.999, p=0.046) and readiness to change smoking behavior (β=0.225; 95% CI: 0.063-0.710; t=2.352, p=0.019). However, public interest in the credibility of the tobacco control regulatory body was negatively associated with NRT use among smokers who tried to quit (adjusted odds ratio, AOR=0.691; 95% CI: 0.526-0.909). The credibility of the tobacco control regulatory body, however, was not associated with the last month's or ever quit attempts.

CONCLUSIONS

The credibility of the tobacco control regulatory body was positively associated with motivation to change smoking behavior but negatively associated with NRT use. Optimizing communication tools with the public is a potential avenue for improving smoking treatment and prevention in Saudi Arabia.

Acute exacerbations of chronic obstructive pulmonary disease in a cohort of Chinese never smokers goes along with decreased risks of recurrent acute exacerbation, emphysema and comorbidity of lung cancer as well as decreased levels of circulating eosinophils and basophils

Acute exacerbations show a significant impact on disease morbidity and mortality in chronic obstructive pulmonary disease (COPD). In contrast to stable COPD, the association of smoking status with clinical and laboratory characteristics in patients with acute exacerbations of COPD (AECOPD) has not been well studied. In this retrospective study, we compared never smokers and ever smokers on their demographic, clinical, and laboratory characteristics in a Chinese clinical cohort of AECOPD. In this cohort comprising 1,034 consecutive patients with AECOPD, never smokers were older (75 vs 70.5 years, padjusted < 0.001) and had a higher body mass index than smokers (21.1 ± 4.0 vs 20.3 ± 3.4, padjusted = 0.028). Furthermore, never smokers showed a decreased risk of recurrent acute exacerbation (13.0 vs 21.8%, padjusted = 0.029), a lower risk of development of emphysema (77.8 vs 89.1%, padjusted < 0.001), a lower prevalence of the co-morbidity of lung cancer (0.5 vs 6.6%, padjusted < 0.001), lower levels of circulating eosinophils (EO; 0.04 × 109/L vs 0.10 × 109/L, padjusted = 0.007) and basophils (BA; 0.02 × 109/L vs 0.03 × 109/L, padjusted = 0.019), and a higher plasma levels of D-dimer (0.62 μg/ml vs 0.51 μg/ml, padjusted = 0.02). Furthermore, multivariate logistic regression analysis identified several risk factor for the recurrent acute exacerbation, such as smoking [odds ratio (OR) = 1.84, 95% CI: 1.03–3.40, p = 0.044], urban residential area (OR = 1.43, 95% CI: 1.01–2.05, p = 0.045), and the presence of emphysema (OR = 2.31, 95% CI: 1.25–4.69, p = 0.012). In conclusion, this study demonstrates that the smoking status of patients is associated with recurrent acute exacerbations, emphysema, lung cancer, and levels of circulating EO and BA in AECOPD. Identification of cigarette smoking as a risk factor for recurrent acute exacerbation supports behavioral intervention of smoking cessation in the management of patients with AECOPD.

How Do Mechanics Guide Fibroblast Activity? Complex Disruptions during Emphysema Shape Cellular Responses and Limit Research

The emphysema death toll has steadily risen over recent decades, causing the disease to become the third most common cause of death worldwide in 2019. Emphysema is currently incurable and could be due to a genetic condition (Alpha-1 antitrypsin deficiency) or exposure to pollutants/irritants, such as cigarette smoke or poorly ventilated cooking fires. Despite the growing burden of emphysema, the mechanisms behind emphysematous pathogenesis and progression are not fully understood by the scientific literature. A key aspect of emphysematous progression is the destruction of the lung parenchyma extracellular matrix (ECM), causing a drastic shift in the mechanical properties of the lung (known as mechanobiology). The mechanical properties of the lung such as the stiffness of the parenchyma (measured as the elastic modulus) and the stretch forces required for inhalation and exhalation are both reduced in emphysema. Fibroblasts function to maintain the structural and mechanical integrity of the lung parenchyma, yet, in the context of emphysema, these fibroblasts appear incapable of repairing the ECM, allowing emphysema to progress. This relationship between the disturbances in the mechanical cues experienced by an emphysematous lung and fibroblast behaviour is constantly overlooked and consequently understudied, thus warranting further research. Interestingly, the failure of current research models to integrate the altered mechanical environment of an emphysematous lung may be limiting our understanding of emphysematous pathogenesis and progression, potentially disrupting the development of novel treatments. This review will focus on the significance of emphysematous lung mechanobiology to fibroblast activity and current research limitations by examining: (1) the impact of mechanical cues on fibroblast activity and the cell cycle, (2) the potential role of mechanical cues in the diminished activity of emphysematous fibroblasts and, finally, (3) the limitations of current emphysematous lung research models and treatments as a result of the overlooked emphysematous mechanical environment.

An integrative analysis to distinguish between emphysema (EML) and alpha-1 antitrypsin deficiency-related emphysema (ADL)-A systems biology approach

Lung Emphysema is an abnormal enlargement of the air sacs followed by the destruction of alveolar walls without any prominent fibrosis. This study primarily identifies the differentially expressed genes (DEGs), interactions between them, and their significant involvement in the activated signaling cascades. The dataset with ID GSE1122 (five normal lung tissue samples, five of usual emphysema, and five of alpha-1 antitrypsin deficiency-related emphysema) from the gene expression omnibus (GEO) was analyzed using the GEO2R tool. The physical association between the DEGs were mapped using the STRING tool and was visualized in the Cytoscape software. The enriched functional processes were identified with the ClueGO plugin's help from Cytoscape. Further integrative functional annotation was performed by implying the GeneGo Metacore™ to distinguish the enriched pathway maps, process networks, and GO processes. The results from this analysis revealed the critical signaling cascades that have been either activated or inhibited due to identified DEGs. We found the activated pathways such as immune response IL-1 signaling pathway, positive regulation of smooth muscle migration, BMP signaling pathway, positive regulation of leukocyte migration, NIK/NF-kappB signaling, and cytochrome-c oxidase activity. Finally, we mapped four crucial genes (CCL5, ALK, TAC1, CD74, and HLA-DOA) by comparing the functional annotations that could be significantly influential in emphysema molecular pathogenesis. Our study provides insights into the pathogenesis of emphysema and helps in developing potential drug targets against emphysema.

Assessing respitatory muscle activity with 18F-FDG-PET/CT in patients with COPD

The purpose of this study was to investigate the metabolic activity of the respiratory muscles in patients with chronic obstructive pulmonary diseases (COPD) and correlate with pulmonary function test results. Thirty-three male patients with a past medical history of smoking and COPD referred to 2-deoxy-2-[¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) because of clinical suspicion of pulmonary cancer were included. The degree of ¹⁸F-FDG uptake was visually quantified (grade 0-3) in the respiratory muscles of the neck, intercostal muscles, and abdominal muscles using mediastinal blood pool uptake and liver uptake as references. Visual grade of ¹⁸F-FDG uptake was compared to forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC) and FEV₁ percent predicted (FEV₁ % pred) by the Wilcoxon-type test for trend. We found significant correlation between the visual grading score and both FEV₁/FVC (P=0.017) and FEV₁ % predicted (P=0.045) for the intercostal muscles. Grade was not significantly associated with pulmonary function tests in either the neck or abdominal muscle groups. ¹⁸F-FDG-PET/CT of the respiratory muscles may have potential in characterization of COPD. Future prospective studies with a larger number of subjects should be undertaken to better understand respiratory muscle physiology in patients with COPD.

Coupled Immunological and Biomechanical Model of Emphysema Progression

Chronic Obstructive Pulmonary Disease (COPD) is a disabling respiratory pathology, with a high prevalence and a significant economic and social cost. It is characterized by different clinical phenotypes with different risk profiles. Detecting the correct phenotype, especially for the emphysema subtype, and predicting the risk of major exacerbations are key elements in order to deliver more effective treatments. However, emphysema onset and progression are influenced by a complex interaction between the immune system and the mechanical properties of biological tissue. The former causes chronic inflammation and tissue remodeling. The latter influences the effective resistance or appropriate mechanical response of the lung tissue to repeated breathing cycles. In this work we present a multi-scale model of both aspects, coupling Finite Element (FE) and Agent Based (AB) techniques that we would like to use to predict the onset and progression of emphysema in patients. The AB part is based on existing biological models of inflammation and immunological response as a set of coupled non-linear differential equations. The FE part simulates the biomechanical effects of repeated strain on the biological tissue. We devise a strategy to couple the discrete biological model at the molecular /cellular level and the biomechanical finite element simulations at the tissue level. We tested our implementation on a public emphysema image database and found that it can indeed simulate the evolution of clinical image biomarkers during disease progression.

Factors Associated With Small Aggressive Non-Small Cell Lung Cancers in the National Lung Screening Trial: A Validation Study

Background

A small proportion of non-small cell lung cancers (NSCLCs) have been observed to spread to distant lymph nodes (N3) or metastasize (M1) or both, while the primary tumor is small (≤3 cm, T1). These small aggressive NSCLCs (SA-NSLSC) are important as they are clinically significant, may identify unique biologic pathways, and warrant aggressive follow-up and treatment. This study identifies factors associated with SA-NSCLC and attempts to validate a previous finding that women with a family history of lung cancer are at particularly elevated risk of SA-NSCLC.

Methods

This study used a case-case design within the National Cancer Institute's National Lung Screening Trial (NLST) cohort. Case patients and "control" patients were selected based on TNM staging parameters. Case patients (n = 64) had T1 NSCLCs that were N3 or M1 or both, while "control" patients (n = 206) had T2 or T3, N0 to N2, and M0 NSCLCs. Univariate and multivariable logistic regression were used to identify factors associated with SA-NSCLC.

Results

In bootstrap bias-corrected multivariable logistic regression models, small aggressive adenocarcinomas were associated with a positive history of emphysema (odds ratio [OR] = 5.15, 95% confidence interval [CI] = 1.63 to 23.00) and the interaction of female sex and a positive family history of lung cancer (OR = 6.55, 95% CI = 1.06 to 50.80).

Conclusions

Emphysema may play a role in early lung cancer progression. Females with a family history of lung cancer are at increased risk of having small aggressive lung adenocarcinomas. These results validate previous findings and encourage research on the role of female hormones interacting with family history and genetic factors in lung carcinogenesis and progression.