Persistent endothelial dysfunction turns the frequent exacerbator COPD from respiratory disorder into a progressive pulmonary and systemic vascular disease

Flow-mediated dilation as a marker of endothelial dysfunction in pulmonary diseases: A narrative review

The endothelium is an active and crucial component of vessels and produces several key regulatory factors for the homeostasis of the entire organism. Endothelial function can be investigated invasively or non-invasively, both in the coronary and peripheral circulation. A widely accepted method for the assessment of endothelial function is measurement of flow-mediated dilation (FMD), which evaluates the vascular response to changes in blood flow. In this current review, we describe FMD applications in the clinical setting of different respiratory diseases: acute SARS-COV2 infection, pulmonary embolism; post-acute SARS-COV2 infection, Chronic Obstructive Pulmonary Disease, Obstructive Sleep Apneas Syndrome, Pulmonary Hypertension, Interstitial Lung Diseases. Emerging evidence shows that FMD might be an effective tool to assess the cardiovascular risk in patients suffering from the undermentioned respiratory diseases as well as an independent predictive factor of disease severity and/or recovery.

Increased Risk of Chronic Obstructive Pulmonary Disease in Patients with Hyperlipidemia: A Nationwide Population-Based Cohort Study

The coexistence of chronic obstructive pulmonary disease (COPD) and cardiovascular disease is common and causes poor prognoses. Hyperlipidemia is the most common risk factor for cardiovascular disease, but the association between hyperlipidemia and COPD remains ambiguous. This study aimed to investigate the risk of COPD development in patients with hyperlipidemia. This retrospective cohort study used information from the National Health Insurance Research Database in Taiwan. We enrolled 21,790 patients with hyperlipidemia and 87,160 control patients without hyperlipidemia for comparison, with a follow-up period of over 10 years. The incidence of new-onset COPD was higher in patients with hyperlipidemia (36.14 per 1000 person-years) than in the controls (22.29 per 1000 person-years). Patients with hyperlipidemia were 1.48 times more likely to develop subsequent COPD than the controls without hyperlipidemia (95% confidence interval 1.44 to 1.53, p < 0.001) following adjustments for age, sex, and comorbidities. In addition, nephropathy, hypertension, congestive heart failure, age, and sex (female) were potential risk factors for developing COPD in patients with hyperlipidemia. Patients with hyperlipidemia may have an increased risk of developing COPD.

Increased Vascular Endothelial Growth Factor Serum Level and the Role of +936C/T Gene Polymorphism in Chronic Obstructive Pulmonary Disease

Background and Objectives: Chronic obstructive pulmonary disease (COPD) represents a debilitating disease, with rising morbidity and mortality. Vascular endothelial growth factor (VEGF) plays a major role in angiogenesis, vascular permeability, and airway remodeling. The purpose of this study was to investigate the relationship between VEGF serum levels and VEGF +936 C/T gene polymorphism (rs3025039) with COPD, for the first time in a Romanian population. Materials and Methods: In total, 120 participants from Transylvania were included in this case-control study. Serum levels of VEGF were determined using an enzyme-linked immune-sorbent assay and rs3025039 was investigated by high molecular weight genomic deoxyribonucleic acid (DNA). Spirometric values, arterial blood gas analysis, and the Six Minute Walk Test (6MWT) outcome were also determined. Results: The serum level of VEGF was higher in the COPD group versus controls (p < 0.001), with a positive correlation with the 6MWT outcome. No significant difference was observed in the VEGF serum levels between VEGF +936C/T genotypes. There was no difference in the VEGF +936C/T genotype between COPD patients and healthy subjects (chi2 test p = 0.92, OR = 1.04, 95%CI = 0.41–2.62), but the presence of the T allele was significantly linked to the presence of COPD (chi2 test p = 0.02, OR = 2.36, 95%CI = 1.12–4.97). Conclusions: Higher VEGF serum levels were found in moderate and severe COPD and were positively correlated with the distance in the 6MWT. No significant difference was found between CC, CT, and TT genotypes of rs3025039 and the presence of COPD. The presence of the T allele was found to be linked to COPD and also to the degree of airway obstruction.

Reversal of emphysema by restoration of pulmonary endothelial cells

Chronic obstructive pulmonary disease (COPD) is marked by airway inflammation and airspace enlargement (emphysema) leading to airflow obstruction and eventual respiratory failure. Microvasculature dysfunction is associated with COPD/emphysema. However, it is not known if abnormal endothelium drives COPD/emphysema pathology and/or if correcting endothelial dysfunction has therapeutic potential. Here, we show the centrality of endothelial cells to the pathogenesis of COPD/emphysema in human tissue and using an elastase-induced murine model of emphysema. Airspace disease showed significant endothelial cell loss, and transcriptional profiling suggested an apoptotic, angiogenic, and inflammatory state. This alveolar destruction was rescued by intravenous delivery of healthy lung endothelial cells. Leucine-rich α-2-glycoprotein-1 (LRG1) was a driver of emphysema, and deletion of Lrg1 from endothelial cells rescued vascular rarefaction and alveolar regression. Hence, targeting endothelial cell biology through regenerative methods and/or inhibition of the LRG1 pathway may represent strategies of immense potential for the treatment of COPD/emphysema.

Pulmonary MicroRNA Changes Alter Angiogenesis in Chronic Obstructive Pulmonary Disease and Lung Cancer

The pulmonary endothelium is dysfunctional in chronic obstructive pulmonary disease (COPD), a known risk factor for lung cancer. The pulmonary endothelium is altered in emphysema, which is disproportionately affected by cancers. Gene and microRNA expression differs between COPD and non-COPD lung. We hypothesised that the alteration in microRNA expression in the pulmonary endothelium contributes to its dysfunction. A total of 28 patients undergoing pulmonary resection were recruited and endothelial cells were isolated from healthy lung and tumour. MicroRNA expression was compared between COPD and non-COPD patients. Positive findings were confirmed by quantitative polymerase chain reaction (qPCR). Assays assessing angiogenesis and cellular migration were conducted in Human Umbilical Vein Endothelial Cells (n = 3-4) transfected with microRNA mimics and compared to cells transfected with negative control RNA. Expression of miR-181b-3p, miR-429 and miR-23c (all p < 0.05) was increased in COPD. Over-expression of miR-181b-3p was associated with reduced endothelial sprouting (p < 0.05). miR-429 was overexpressed in lung cancer as well and exhibited a reduction in tubular formation. MicroRNA-driven changes in the pulmonary endothelium thus represent a novel mechanism driving emphysema. These processes warrant further study to determine if they may be therapeutic targets in COPD and lung cancer.

Endothelial Dysfunction during Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Chronic obstructive pulmonary disease (COPD) is characterized by high cardiovascular risk, which is further amplified during acute COPD exacerbations (AECOPD). Endothelial dysfunction has been previously suggested as one of the potential pathogenetic mechanisms. In order to study the effects of AECOPD on endothelial function assessed by available functional methods, we performed a literature search involving Pubmed and Scopus databases. Eligible studies were those that included adult patients with COPD and evaluated endothelial damage via semi-invasive or noninvasive functional methods, during AECOPD and after recovery or in stable condition. Newcastle-Ottawa Scale was applied to evaluate the quality of retrieved studies. Endothelial function was significantly impaired during AECOPD compared to recovery/stable condition (SMD: -0.87, 95%CI [-1.19, -0.55]). Patients during AECOPD presented a significantly worse response in endothelium-dependent (flow-mediated dilatation WMD: -2.59, 95%CI [-3.75, -1.42]) and independent vasodilation (nitroglycerine-mediated dilatation WMD: -3.13, 95%CI [-5.18, -1.09]) compared to recovery. Sensitivity analyses confirmed the above results. In conclusion, endothelium-dependent and independent vasodilation is worse during AECOPD compared to the stable condition. Endothelial dysfunction could play a role in the high cardiovascular risk during AECOPD.

[Endothelium-related and neuro-mediated mechanisms of emphysema development in chronic obstructive pulmonary disease]

Emphysema is one of the main manifestations of chronic obstructive pulmonary disease (COPD), and smoking is one of the most significant risk factors. The results of studies in humans and animals show the vascular endothelium initiates and modulates the main pathological processes in COPD and smoking is an important factor initiating, developing and persisting inflammation and remodeling of blood vessels and tissues, including the destruction of small respiratory tracts with the development of lung tissue destruction and emphysema. The latest studies describe mechanisms not just associated with the endothelium, but specific neuro-mediated mechanisms. There is reason to believe that neuro-mediated and neuro-similar mechanisms associated and not related to endothelial dysfunction may play the significant role in the pathogenesis of COPD and emphysema formation. Information about components and mechanisms of neurogenic inflammation in emphysema development is fragmentary and not systematized in the literature. It is described that long-term tobacco smoking can initiate processes not only of cells and tissues damage, but also become a trigger for excessive release of neurotransmitters, which entails whole cascades of adverse reactions that have an effect on emphysema formation. With prolonged and/or intensive stimulation of sensor fibers, excessive release of neuropeptides is accompanied by a number of plastic and destructive processes due to a cascade of pathological reactions of neurogenic inflammation, the main participants of which are classical neuropeptides and their receptors. The most important consequences can be the maintenance and stagnation of chronic inflammation, activation of the mechanisms of destruction and remodeling, inadequate repair processes in response to damage, resulting in irreversible loss of lung tissue. For future research, there is interest to evaluate the possibilities of therapeutic and prophylactic effects on neuro-mediated mechanisms of endothelial dysfunction and damage emphysema in COPD and smoking development.

Hypermethylation of mitochondrial transcription factor A induced by cigarette smoke is associated with chronic obstructive pulmonary disease

Purpose of the study: Cigarette smoking is a leading environmental contributor to chronic obstructive pulmonary disease (COPD), but its epigenetic regulation of mtTFA gene remains elusive. This study aims to explore the relationship of DNA methylation of mtTFA and cigarette smoking in COPD. Materials and Methods: We analyzed DNA methylation on mtTFA promoters in clinical samples from COPD patients and subjects with normal pulmonary function. Expression of mtTFA mRNA in the clinical samples and mtTFA mRNA and protein in human umbilical vein endothelial cells(HUVECs) treated with cigarette smoke extract (CSE) was evaluated. mtTFA mRNA and protein levels were measured to determine effects of demethylation agents on CSE-treated HUVECs. Results: The DNA methylation level of the mtTFA promoter was significantly increased in COPD group. Expression of mtTFA mRNA was downregulated in the lungs as a consequence of hypermethylation of mtTFA promoter. Expression of mtTFA mRNA and protein was downregulated in CSE-treated HUVECs as a consequence of hypermethylation of the mtTFA promoter. mtTFA expression in CSE-treated HUVECs was restored by the methylation inhibitor, 5-aza-2'-deoxycytidine(AZA). Conclusions: Cigarette smoke-induced hypermethylation of the mtTFA promoter is related to the initiation and progression of COPD. Our finding may provide a new strategy for the intervention of COPD by developing demethylation agents targeting mtTFA hypermethylation.

GOLD stage predicts thoracic aortic calcifications in patients with COPD

Although some of the associations between chronic obstructive pulmonary disease (COPD) and atherosclerosis are based on shared risk factors such as smoking, recent epidemiological evidence suggests that COPD is a risk factor for vascular disease due to systemic inflammation. The present study assessed the hypothesis that disease severity (as expressed by the GOLD stage) independently predicts the extent of vascular calcifications. A total of 160 smokers diagnosed with COPD (GOLD I-IV, 40 subjects of each GOLD stage) and 40 smokers at risk (GOLD 0; median age of 60 years old; Q1:56;Q3:65; 135 males and 65 females) underwent non-contrast, non-electrocardiography synchronized chest computerised tomography. The volume of thoracic aortic calcifications was quantified semi-automatically within a region from T1 through T12. Multiparametric associations with GOLD stage, smoking history, sex, age, body mass index and emphysema index were evaluated using generalized linear regression analysis. Thoracic aortic calcifications were highly prevalent in this cohort (187/200 subjects, 709 (Q1:109;Q3:2163) mm³). Analysis of variance on ranks demonstrated a significant difference in calcium between different GOLD-stages as well as patients at risk of COPD (F=36.8, P<0.001). In the multivariable analysis, GOLD-stages were indicated to be predictive of thoracic aortic calcifications (P≤0.0033) besides age (P<0.0001), while age appeared to be the strongest predictor. Other variables were not statistically linked to thoracic aortic calcifications in the multivariable model. COPD severity, as expressed by the GOLD-stage, is a significant predictor of thoracic aortic calcifications, independent of covariates such as age or tobacco consumption.

Next-generation sequencing approaches for the study of genome and epigenome toxicity induced by sulfur mustard

Sulfur mustard (SM) is an extensive nucleophilic and alkylating agent that targets different tissues. The genotoxic property of SM is the most threatening effect, because it is associated with detrimental inflammations and susceptibility to several kinds of cancer. Moreover, SM causes a wide variety of adverse effects on DNA which result in accumulation of DNA adducts, multiple mutations, aneuploidies, and epigenetic aberrations in the genome. However, these adverse effects are still not known well, possibly because no valid biomarkers have been developed for detecting them. The advent of next-generation sequencing (NGS) has provided opportunities for the characterization of these alterations with a higher level of molecular detail and cost-effectivity. The present review introduces NGS approaches for the detection of SM-induced DNA adducts, mutations, chromosomal structural variation, and epigenetic aberrations, and also comparing and contrasting them with regard to which might be most advantageous.

High risk of subclinical atherosclerosis in COPD exacerbator phenotype

It is not known whether COPD exacerbations contribute to an increased vascular risk already associated with the disease. For this reason, we prospectively evaluated 127 patients referred for a monographic COPD consultation. We classify as exacerbators those who had experienced two or more moderate exacerbations in the previous year, or who had had a hospital admission. All underwent a blood analysis, respiratory function tests, global cardiovascular and coronary risk estimates (with four of the most frequently used scores, and the Chronic Obstructive Pulmonary Disease Coronaropathy Risk (COPDCoRi) score, respectively); and an EcoDoppler to measure carotid intima-media thickness and the ankle-brachial index. Finally, we included 50 patients with exacerbator phenotypes and 57 with non-exacerbator phenotypes, ranging from 63 ± 7 years old, 74% of whom were male. The exacerbator phenotype increased the risk of carotid intima-media thickness above the 75th percentile range by a factor of almost three, independently of the severity of COPD and global cardiovascular risk. The association between the exacerbator phenotype and high c-IMT was more evident in patients under 65. In conclusion, the presence of subclinical atherosclerosis is independently associated with the exacerbator phenotype, with more pronounced differences in younger patient; which suggests that we should intensify control of vascular risk factors in these groups of patients.

COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the "vascular COPD phenotype" including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested on cell culture systems, animal models of COPD, and/or smokers and COPD patients.

Association of asthma-chronic obstructive pulmonary disease overlap syndrome with coronary artery disease, cardiac dysrhythmia and heart failure: a population-based retrospective cohort study

OBJECTIVES

Patients with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and cardiovascular diseases (CVDs) share common risk factors. However, the association between ACOS and the incidence of CVDs has not been reported. This study investigated the relationship between CVDs and ACOS in the general population.

SETTING

Data were obtained from Taiwan's National Health Insurance Research Database for the period 2000 to 2010.

PARTICIPANTS

The ACOS cohort comprised patients (n=5814) who had received a diagnosis of asthma and COPD. The non-ACOS cohort comprised patients who had not received a diagnosis of asthma or COPD and were matched to the ACOS cohort (2:1) by age, sex and index date (n=11 625).

PRIMARY AND SECONDARY OUTCOME MEASURES

The cumulative incidence of CVDs-coronary artery disease (CAD), cardiac dysrhythmia (CD) and heart failure (HF)-was calculated. Cox proportional regression analysis was employed to examine the relationship between ACOS and CVDs.

RESULTS

After adjustment for multiple confounding factors-age, sex, comorbidities and medications-patients with ACOS were associated with a significantly higher risk of CVDs; the adjusted HRs (aHRs; 95% CI) for CAD, CD and HF were 1.62 (1.50 to 1.76), 1.44 (1.30 to 1.61) and 1.94 (1.73 to 2.19), respectively, whereas those of beta-blockers treatment for CAD, CD and HF were 1.19 (0.92 to 1.53), 0.90 (0.56 to 1.45) and 0.82 (0.49 to 1.38). The aHR of atenolol treatment for CD was 1.72 (1.01 to 2.93). The aHRs (95% CIs) of ACOS without acute exacerbation of COPD (AE-COPD) for CAD, CD and HF were 1.85 (1.70 to 2.01), 1.57 (1.40 to 1.77) and 2.07 (1.82 to 2.35), respectively.

CONCLUSION

ACOS was associated with higher CVD risk, even without the presence of previous comorbidities or AE-COPD. No significant differences in CVD events were observed in the ACOS cohort using beta-blockers, except for those using atenolol for treating CD.

The role of the endothelium in asthma and chronic obstructive pulmonary disease (COPD)

COPD and asthma are important chronic inflammatory disorders with a high associated morbidity. Much research has concentrated on the role of inflammatory cells, such as the neutrophil, in these diseases, but relatively little focus has been given to the endothelial tissue, through which inflammatory cells must transmigrate to reach the lung parenchyma and cause damage. There is evidence that there is an abnormal amount of endothelial tissue in COPD and asthma and that this tissue and its’ progenitor cells behave in a dysfunctional manner. This article reviews the evidence of the involvement of pulmonary endothelium in COPD and asthma and potential treatment options for this.

Systemic and Pulmonary Vascular Remodelling in Chronic Obstructive Pulmonary Disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is associated with subclinical systemic atherosclerosis and pulmonary vascular remodelling characterized by intimal hyperplasia and luminal narrowing. We aimed to determine differences in the intimal thickening of systemic and pulmonary arteries in COPD subjects and smokers. Secondary aims include comparisons with a non-smokers group; determining the clinical variables associated with systemic and pulmonary intimal thickening, and the correlations between systemic and pulmonary remodelling changes.

Methods

All consecutive subjects undergoing lung resection were included and divided into 3 groups: 1) COPD, 2) smokers, and 3) non-smokers. Sections of the 5th intercostal artery and muscular pulmonary arteries were measured by histo-morphometry. Four parameters of intimal thickening were evaluated: 1) percentage of intimal area (%IA), 2) percentage of luminal narrowing, 3) intimal thickness index, and 4) intima-to-media ratio.

Results

In the adjusted analysis, the systemic arteries of COPD subjects showed greater intimal thickening (%IA) than those of smokers (15.6±1.5% vs. 14.2±1.6%, p = 0.038). In the pulmonary arteries, significant differences were observed for %IA between the 2 groups (37.3±2.2% vs. 29.3±2.3%, p = 0.016). Among clinical factors, metabolic syndrome, gender and COPD status were associated with the systemic intimal thickening, while only COPD status was associated with pulmonary intimal thickening. A correlation between the %IA of the systemic and pulmonary arteries was observed (Spearman’s rho = 0.46, p = 0.008).

Conclusions

Greater intimal thickening in systemic and pulmonary arteries is observed in COPD patients than in smokers. There is a correlation between systemic and pulmonary vascular remodelling in the overall population.