Novel insights into the aetiology and pathophysiology of increased airway inflammation during COPD exacerbations

Knockdown of RTEL1 Alleviates Chronic Obstructive Pulmonary Disease by Modulating M1, M2 Macrophage Polarization and Inflammation

Chronic obstructive pulmonary disease (COPD) is a common chronic disease characterized by airflow obstruction, which seriously threatens people's health. The COPD mouse model was established with cigarette smoke induction. Hematoxylin-eosin staining and Masson staining were carried out to observe the pathological changes of lung tissues in COPD mice. RTEL1 was silenced in COPD mice, and immunohistochemistry was used to detect RTEL1, ki67 and Caspase-3 expression. The role of RTEL1 in inflammation were evaluated by ELISA, and the impacts of RTEL1 on M1 and M2 macrophage markers (iNOS and CD206) were evaluated by qPCR and western blotting. In COPD model, there was an increase in the number of inflammatory cells, with slightly disorganized cell arrangement, unclear hierarchy, condensed and solidified nuclei, while knockdown of RTEL1 improved the inflammatory infiltration. Moreover, knockdown of RTEL1 reduced ki67-positive cells and increased Caspase-3 positive cells in COPD group. The increased inflammatory factors (IL-1β, MMP-9, TNF-α, IL-4, IL-6, and IL-23) in COPD were suppressed by knockdown of RTEL1, while iNOS was raised and CD206 was inhibited. In conclusion, knockdown of RTEL1 promoted M1 and inhibited M2 macrophage polarization and inflammation to alleviate COPD.

The role of Sodium-Glucose Transporter-2 Inhibitors (SGLT-2i) in preventing chronic obstructive disease exacerbation in patients with diabetes and COPD: An electronic health database analysis

BACKGROUND

Sodium Glucose Transporter 2 inhibitor (SGLT-2i) medications reduce inflammation, improve glycemic control, and impart weight loss, all of which may play a role in chronic obstructive pulmonary disease (COPD) pathophysiology.

OBJECTIVES

The primary objective of our study was to explore the incidence of COPD exacerbation in patients with diabetes and COPD on SGLT-2i medications. The secondary objective was to assess the impact of SGLT-2i medications on COPD exacerbations needing hospitalization, ICU admission, and mechanical ventilation.

METHODS

This was a retrospective cohort analysis of COPD patients with diabetes enrolled in the COPD registry at a Mid-west Tertiary care teaching hospital from January 1, 2022, to December 31, 2022. We used Slicer-Dicer, a self-service cohort exploration tool embedded in EPIC for data extraction.

RESULTS

We had 31,411 patients registered with the COPD registry during the study period. Of these, 18,713 had diabetes, and 1295 patients were on SGLT-2i medication. The incidence of COPD exacerbation, including severe COPD exacerbation needing hospitalization, was significantly lower in the SGLT-2i medication group (3.16% vs 18.3%, p < 0.05; 1.2% vs 5.04%, p < 0.05). Also, there was a non-significant trend suggesting that the incidence of COPD exacerbation needing intensive care unit admission and intubation was lower in the SGLT-2i medication group (0.07% vs 3.4%; 0 vs 0.04%). SGLT-2i medication use was associated with reduced incidence of COPD exacerbation irrespective of underlying control of diabetes.

CONCLUSIONS

Our study suggests possible role of SGLT-2i in preventing COPD exacerbation. Randomized trials are needed in the future to confirm or refute these findings.

Associations between short-term exposure to wildfire particulate matter and respiratory outcomes: A systematic review

BACKGROUND

The frequency and severity of wildfires have been sharply increasing due to climate change, which largely contributes to ambient particulate matter (PM) pollution. We conducted a systematic review focusing on the short-term relationships between PM attributable to wildfires (wildfire-specific PM) and diverse respiratory endpoints, with a comparison between the effects of wildfire-specific PM vs. all-source/non-wildfire PM.

METHODS

A comprehensive online search for the literature published from 2000 to 2022 was conducted through PubMed, Web of Sciences, Scopus, and EMBASE. We applied search terms related to wildfire smoke and respiratory health outcomes.

RESULTS

In total, 3196 articles were retrieved, and 35 articles were included in this review. Most studies focused on the associations of wildfire-specific PM with an aerodynamic diameter of <2.5 μm (PM2.5) with respiratory emergency department visits or hospitalizations, with a time-series or case-crossover study design. Studies were mostly conducted in the United States, Canada, and Australia. Positive associations of wildfire-specific PM with respiratory morbidity were observed in most studies. Studies that focused on respiratory mortality were limited. Females can be more vulnerable to the respiratory impacts of wildfire PM, while the evidence of vulnerable subpopulations among different age groups was inconclusive. Few studies compared the effects of wildfire-specific vs. all-source/non-wildfire PM, and some reported higher levels of toxicity of wildfire-specific PM, potentially due to its distinct chemical and physical compositions. Asthma and chronic obstructive pulmonary disease were the most studied diseases, and both were adversely affected by wildfire-specific PM.

CONCLUSION

To our knowledge, this is the first review that systematically summarized the associations of wildfire-specific PM exposure with adverse respiratory outcomes and compared associations of wildfire-specific vs. all-source/non-wildfire PM. Further investigations may add to the literature by examining the impacts on respiratory mortality and the effects of specific PM components from different types of wildfires.

The traditional herbal formulation, Jianpiyifei II, reduces pulmonary inflammation induced by influenza A virus and cigarette smoke in mice

Chronic obstructive pulmonary disease (COPD) is a worldwide chronic inflammatory lung disease, and influenza A virus (IAV) infection is a common cause of acute exacerbations of COPD (AECOPD). Therefore, targeting viral infections represents a promising strategy to prevent the occurrence and development of inflammatory flare ups in AECOPD. Jianpiyifei II (JPYFII) is a traditional herbal medicine used in China to treat patients with COPD, and its clinical indications are not well understood. However, investigation of the anti-inflammatory effects and underlying mechanism using an animal model of smoking have been reported in a previous study by our group. In addition, some included herbs, such as Radix astragali and Radix aupleuri, were reported to exhibit antiviral effects. Therefore, the aim of the present study was to investigate whether JPYFII formulation relieved acute inflammation by clearing the IAV in a mouse model that was exposed to cigarette smoke experimentally. JPYFII formulation treatment during smoke exposure and IAV infection significantly reduced the number of cells observed in bronchoalveolar lavage fluid (BALF), expression of proinflammatory cytokines, chemokines, superoxide production, and viral load in IAV-infected and smoke-exposed mice. However, JPYFII formulation treatment during smoke exposure alone did not reduce the number of cells in BALF or the expression of Il-6, Tnf-a, and Il-1β. The results demonstrated that JPYFII formulation exerted an antiviral effect and reduced the exacerbation of lung inflammation in cigarette smoke (CS)-exposed mice infected with IAV. Our results suggested that JPYFII formulation could potentially be used to treat patients with AECOPD associated with IAV infection.

Coupling Effect of Double Lungs on a VCV Ventilator with Automatic Secretion Clearance Function

For patients with mechanical ventilation, secretions in airway are harmful and sometimes even mortal, it's of great significance to clear secretion timely and efficiently. In this paper, a new secretion clearance method for VCV (volume-controlled ventilation) ventilator is put forward, and a secretion clearance system with a VCV ventilator and double lungs is designed. Furthermore, the mathematical model of the secretion clearance system is built and verified via experimental study. Finally, to illustrate the influence of key parameters of respiratory system and secretion clearance system on the secretion clearance characteristics, coupling effects of two lungs on VCV secretion clearance system are studied by an orthogonal experiment, it can be obtained that rise of tidal volume adds to efficiency of secretion clearance while effect of area, compliance, and suction pressure on efficiency of secretion clearance needs further study. Rise of compliance improves bottom pressure of secretion clearance while rise of area, tidal volume, and suction pressure decreases bottom pressure of secretion clearance. This paper can be referred to in researches of secretion clearance for VCV.

Impaired mRNA Expression of the Migration Related Chemokine Receptor CXCR4 in Mesenchymal Stem Cells of COPD Patients

Defective tissue repair and remodeling are main aspects of Chronic Obstructive Pulmonary Disease (COPD) pathophysiology. Bone marrow mesenchymal stem cells (BM-MSCs) have been implicated in this direction, as their functional impairment and recruitment could possibly contribute to disease development and progression. The present study characterizes for the first time the expression of migration related chemokine receptors and their ligands in BM-MSCs from COPD patients. CXCR4/SDF1a and CCR7/CCL19-CCL21 mRNA levels were evaluated in BM-MSCs obtained from twelve COPD patients and seven healthy donors. SDF1a protein levels in sera and BM-MSCs' conditioned media were also evaluated. CXCR4, SDF1a, CCL19, and CCL21 mRNA levels were significantly reduced in COPD BM-MSCs while CCR7 levels were undetectable. Notably, SDF1a protein levels were marginally elevated in both patient sera and BM-MSCs' conditioned media while the increase in SDF1a serum levels significantly correlated with disease severity in COPD. Our findings show posttranscriptional regulation of SDF1a levels in BM-MSCs of COPD patients and significant downregulation of SDF1a and CXCR4 mRNA indicating an involvement of the SDF1a signaling pathway in the disease pathophysiology.

Paradigms in chronic obstructive pulmonary disease: phenotypes, immunobiology, and therapy with a focus on vascular disease

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous syndrome that represents a major global health burden. COPD phenotypes have recently emerged based on large cohort studies addressing the need to better characterize the syndrome. Though comprehensive phenotyping is still at an early stage, factors such as ethnicity and radiographic, serum, and exhaled breath biomarkers have shown promise. COPD is also an immunological disease where innate and adaptive immune responses to the environment and tobacco smoke are altered. The frequent overlap between COPD and other systemic diseases, such as cardiovascular disease, has influenced COPD therapy, and treatments for both conditions may lead to improved patient outcomes. Here, we discuss current paradigms that center on improving the definition of COPD, understanding the immunological overlap between COPD and vascular inflammation, and the treatment of COPD-with a focus on comorbid cardiovascular disease.

DIMENSIONLESS OPTIMIZATION STUDY ON A VENTILATOR WITH SECRETION CLEARANCE FUNCTION

To improve the efficiency and safety of secretion clearance, a novel ventilator (SC ventilator) with an automatic secretion clearance function is proposed. To lay a foundation for the optimization of the SC ventilator, the basic mathematical model of the ventilation system is derived. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression for simulation. Through the experimental and simulation study on the SC ventilation system, it can be concluded that: firstly, the mathematical model is proved to be authentic and reliable. Secondly, the influences of the three key parameters on the dynamics of the SC ventilation system are carried out. Last, to guarantee the pressure in the lung is higher than the expiratory positive airway pressure, the dimensionless minimum pressure in the flexible tube should be set higher than 0.9164, the dimensionless suction pressure should be set higher than 0.79.

The host immune response contributes to Haemophilus influenzae virulence

BACKGROUND

There is compelling evidence that infections with non-typeable Haemophilus influenzae (NTHi) are associated with exacerbations in COPD patients. However, NTHi has also been isolated frequently during clinically stable disease. In this study we tested the hypothesis that genetically distinct NTHi isolates obtained from COPD patients differ in virulence which could account for dissimilarities in the final outcome of an infection (stable vs. exacerbation).

RESULTS

NTHi isolates (n = 32) were obtained from stable COPD patients, or during exacerbations. Genetically divergent NTHi isolates were selected and induction of inflammation was assessed as an indicator of virulence using different in vitro models. Despite marked genomic differences among NTHi isolates, in vitro studies could not distinguish between NTHi isolates based on their inflammatory capacities. Alternatively, when using a whole blood assay results demonstrated marked inter-, but not intra-individual differences in cytokine release between healthy volunteers irrespective of the origin of the NTHi isolate used.

CONCLUSION

Results suggest that the individual immune reactivity might be an important predictor for the clinical outcome (exacerbation vs. no exacerbation) following NTHi infection.

[Treating COPD in chronic patients in a primary-care setting]

The aging of the populations in Western countries entails an increase in chronic diseases, which becomes evident with the triad of age, comorbidities and polymedication. chronic obstructive pulmonary disease represents one of the most important causes of morbidity and mortality, with a prevalence in Spain of 10.2% in the population aged 40 to 80. In recent years, it has come to be defined not only as an obstructive pulmonary disease, but also as a systemic disease. Some aspects stand out in its management: smoking, the main risk factor, even though avoidable, is an important health problem; very important levels of underdiagnosis and little diagnostic accuracy, with inadequate use of spirometry; chronic patient profile; exacerbations that affect survival and cause repeated hospitalizations; mobilization of numerous health-care resources; need to propose integral care (health-care education, rehabilitation, promotion of self-care and patient involvement in decision-making).

Trends in COPD prevalence and exacerbation rates in Dutch primary care

BACKGROUND

Changes in the burden of chronic obstructive pulmonary disease (COPD) and its exacerbations on primary health care are not well studied.

AIM

To identify trends in the prevalence of physician-diagnosed COPD and exacerbation rates by age, sex, and socioeconomic status in a general practice population.

DESIGN OF STUDY

Trend analysis of COPD data from a 27-year prospective cohort of a dynamic general practice population.

SETTING

Data were taken from the Continuous Morbidity Registration Nijmegen.

METHOD

For the period 1980-2006, COPD and COPD exacerbation data were extracted for patients aged ≥40 years. Data were standardised for the composition of the Continuous Morbidity Registration population in the year 2000. Regression coefficients for trends were estimated by sex, age, and socioeconomic status. Rate ratios were calculated for prevalence differences in different demographic subgroups.

RESULTS

During the study period, the overall COPD prevalence decreased from 72.7 to 54.5 per 1000 patients per year. The exacerbation rate decreased from 44.1 to 31.5 per 100 patients, and the percentage of patients with COPD who had exacerbations declined from 27.6% to 21.0%. The prevalence of COPD increased significantly in women, in particular those aged ≥65 years with low socioeconomic status. Decreases in exacerbation rates and percentages of patients with exacerbations were independent of sex, age, and socioeconomic status.

CONCLUSION

The decline in COPD prevalence and exacerbation rates suggests a reduction of the burden on Dutch primary care. The increase of the prevalence in women indicates a need to focus on this particular subgroup in COPD management and research.

Longitudinal follow-up of systemic inflammation after acute exacerbations of COPD

BACKGROUND

Acute exacerbations are important in the clinical course of COPD, yet the underlying mechanisms are poorly understood. Systemic inflammation is now considered as an important component in the disease process. In this study we evaluated longitudinally the systemic inflammation during hospital treatment for acute exacerbation and after clinical recovery.

METHODS

Blood was collected on day 0, 1, 4 and 8 in 21 patients admitted for an acute exacerbation of COPD and at 1 month, 3 months and 6 months after discharge. Systemic inflammation was determined by measurement of the pro-inflammatory markers interleukin (IL)-6, soluble tumor necrosis factor (TNF) receptors sTNFR55 and sTNFR75, the anti-inflammatory mediator sIL-1RII, and bactericidal permeability increasing protein (BPI) as a marker of neutrophil activation. In addition, plasma level of Trolox antioxidant capacity (TEAC) was determined. Healthy age-matched controls were measured for the same markers at one time-point.

RESULTS

All inflammatory markers analyzed were elevated on first day of admission for exacerbation of COPD, as compared to healthy controls. During treatment, levels of IL-6, and sTNFR75 rapidly decreased, whereas sTNFR55 and BPI remained elevated. Moreover, sIL-1RII and TEAC increased during first 8 days of treatment. In the stable condition all inflammatory markers returned to values comparable to healthy controls, with the exception of BPI, which remained persistently elevated compared to healthy controls.

CONCLUSION

This study clearly demonstrates upregulation of systemic inflammation in acute exacerbations of COPD. Attenuation of systemic inflammation may offer new perspectives in the management of COPD patients to reduce the burden of exacerbations.