Systemic inflammation in peripheral arterial disease with or without coexistent chronic obstructive pulmonary disease: analysis of selected markers

Oxygen dependence of endothelium-dependent vasodilation: importance in chronic obstructive pulmonary disease

INTRODUCTION

Epidemiological studies have shown increased morbidity and mortality in patients with coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD). We aimed to characterize the oxygen dependence of endothelial function in patients with CAD and coexisting COPD.

MATERIAL AND METHODS

In CAD patients with and without COPD (n = 33), we non-invasively measured flow-mediated dilation (FMD) and intima-media thickness (IMT) of the brachial artery (BA), forearm blood flow (FBF), and perfusion of the cutaneous microcirculation with laser Doppler perfusion imaging (LDPI). In an experimental setup, vascular function was assessed in healthy volunteers (n = 5) breathing 12% oxygen or 100% oxygen in comparison to room air.

RESULTS

COPD was associated with impaired FMD (3.4 ±0.5 vs. 4.2 ±0.6%; p < 0.001) and increased IMT (0.49 ±0.04 vs. 0.44 ±0.04 mm; p <0.01), indicating functional and structural alterations of the BA in COPD. Forearm blood flow and LDPI were comparable between the groups. Flow-mediated dilation correlated with capillary oxygen pressure (pO2, r = 0.608). Subgroup analysis in COPD patients with pO2 > 65 mm Hg and pO2 ≤ 65 mm Hg revealed even lower FMD in patients with lower pO2 (3.0 ±0.5 vs. 3.7 ±0.4%; p < 0.01). Multivariate analysis showed that pO2 was a predictor of FMD independent of the forced expiratory volume and pack years. Exposure to hypoxic air led to an acute decrease in FMD, whereby exposure to 100% oxygen did not change vascular function.

CONCLUSIONS

Our data suggest that in CAD patients with COPD, decreased systemic oxygen levels lead to endothelial dysfunction, underlining the relevance of cardiopulmonary interaction and the potential importance of pulmonary treatment in secondary prevention of vascular disease.

Total phenolic, flavonoid, alkaloid and iridoid content and preventive effect of Lider-7-tang on lipopolysaccharide-induced acute lung injury in rats

Lider-7-tang, a medicine used for the treatment of respiratory diseases especially pneumonia and fever in Mongolian Traditional Medicine, was selected for this phytochemical and pharmacological study. The objectives of the study were to determine total biological active substances and analyze the effects of Lider-7-tang treatment in rats with acute lung injury (ALI). Quantitative determination of the total active constituents (phenolic, flavonoid, iridoid and alkaloid) of the methanol extract of Lider-7-tang was performed using Folin-Ciocalteu reagent, aluminum chloride reagent, Trim-Hill reagent, and Bromocresol green reagent, respectively. A total of fifty 8-10-week-old male Wistar rats (200-240 g) were randomized into three groups: control group, lipopolysaccharide (LPS) group (7.5 mg/kg) and LPS+Lider-7 group (90 mg/kg Lider-7-tang before LPS administration). The total content of alkaloids was 0.2±0.043%, total phenols 7.8±0.67%, flavonoids 3.12±0.206%, and iridoids 0.308±0.0095%. This study also evaluated the effects of Lider-7 on levels of inflammatory mediators by observing histopathological features associated with LPS-induced ALI. The rats pretreated with Lider-7 had significantly lower levels of IL-6 (at 3 and 6 h), and TNF-α (at 3, 6, 9, and 12 h). The current study showed that Lider-7 exerted a preventive effect against LPS-induced ALI, which appeared to be mediated by inhibiting the release of pro-inflammatory cytokines.

Lower extremity and carotid artery disease in COPD

In view of their common chronic inflammatory process, we sought to determine the linkage between peripheral artery disease and chronic obstructive pulmonary disease (COPD). 107 COPD patients (mean±sd age 64.6±10.4 years, 52.2% male) and 22 control smokers without previously diagnosed peripheral artery disease underwent standardised angiological examination for lower extremity artery disease (LEAD) and carotid artery disease. LEAD was significantly more prevalent in COPD patients than in controls (80.4% versus 54.5%, p=0.002). Among COPD patients, 57.0%, 12.2%, 10.3% and 0.9% were found to be in Fontaine stages I, IIA, IIB and III, respectively. As with carotid artery disease, its frequency increased from 36.4% in controls to 58.9% in COPD patients (p=0.003). Carotid plaque burden, LEAD Fontaine degrees as well as pulse wave index and ankle-brachial index manifested significant impairment over percentage predicted forced expiratory volume in 1 s (FEV1 % pred) (p=0.02, p<0.001, p=0.01 and p<0.001, respectively). Multivariate analysis revealed that COPD Global Initiative for Chronic Obstructive Lung Disease status was the strongest independent predictor for the presence of plaque in lower extremity arteries (odds ratio 1.63, 95% CI 1.19-2.25, p=0.003) and carotids (odds ratio 1.66, 95% CI 1.14-2.44, p=0.009). As compared with control smokers, peripheral artery disease is diagnosed in a sizeable proportion of COPD patients and exhibits significant distributive differences over FEV1 % pred that exceed the susceptibility conferred by common cardiovascular stressors.

Impact of I/D polymorphism of ACE gene on risk of development and course of chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) affects more than 10% of the world's population over 40 years of age. The main exogenous risk factor is cigarette smoking; however, only 20% of smokers develop COPD, indicating that some other factors, e.g. genetic, may play an important role in the disease pathogenesis. Recent research indicates that ACE (angiotensin-converting enzyme) may be a susceptibility gene for asthma or COPD. The aim of our study was to determine the influence of I/D (insertion/deletion) polymorphism of the ACE gene (AluYa5, rs4646994) on the risk and course of COPD.

MATERIAL AND METHODS

We investigated ACE I/D polymorphism in 206 COPD and 165 healthy Caucasian subjects.

RESULTS

In the generalized linear model (GLZ) analysis of the influence of selected factors on presence of COPD we found a significant independent effect for male sex (repeatedly increases the risk of COPD, OR = 7.7, p = 0.049), as well as smoking or lower body mass index, but only in combination with older age (OR = 0.96, p = 0.003 and OR = 1.005, p = 0.04 respectively). Interestingly, analysis of factors which may influence the risk of a higher number of exacerbations demonstrated that occurrence of DD genotype, but only in men, is associated with a lower risk (OR = 0.7, p = 0.03) of this complication.

CONCLUSIONS

We suggest that ACE may not be a susceptibility gene for the origin of COPD but a disease-modifying gene. Since the impact of I/D polymorphism of the ACE gene on COPD risk is moderate or negligible, other molecular changes, that will help predict the development of this disease, should still be sought.

Computational drug repositioning for peripheral arterial disease: prediction of anti-inflammatory and pro-angiogenic therapeutics

Peripheral arterial disease (PAD) results from atherosclerosis that leads to blocked arteries and reduced blood flow, most commonly in the arteries of the legs. PAD clinical trials to induce angiogenesis to improve blood flow conducted in the last decade have not succeeded. We have recently constructed PADPIN, protein-protein interaction network (PIN) of PAD, and here we combine it with the drug-target relations to identify potential drug targets for PAD. Specifically, the proteins in the PADPIN were classified as belonging to the angiome, immunome, and arteriome, characterizing the processes of angiogenesis, immune response/inflammation, and arteriogenesis, respectively. Using the network-based approach we predict the candidate drugs for repositioning that have potential applications to PAD. By compiling the drug information in two drug databases DrugBank and PharmGKB, we predict FDA-approved drugs whose targets are the proteins annotated as anti-angiogenic and pro-inflammatory, respectively. Examples of pro-angiogenic drugs are carvedilol and urokinase. Examples of anti-inflammatory drugs are ACE inhibitors and maraviroc. This is the first computational drug repositioning study for PAD.

Combined autologous bone marrow mononuclear cell and gene therapy as the last resort for patients with critical limb ischemia

INTRODUCTION

Our study was designed to investigate the safety and efficacy of combined autologous bone marrow mononuclear cell (MNC) and gene therapy in comparison to conventional drug therapy in patients with critical limb ischemia (CLI).

MATERIAL AND METHODS

Thirty-two patients with CLI persisting for 12-48 months (average time 27.5 months) were randomized into 2 groups, each group consisting of 16 patients. In the first group, administration of autologous bone marrow MNC and vascular endothelial growth factor (VEGF) plasmid was performed. The patients from the second group were treated pharmacologically with pentoxifylline. Ankle-brachial index (ABI) was measured and angiography was performed before and finally 3 months after treatment. The pain was evaluated using the Visual Analog Scale (VAS) before and after 3 months.

RESULTS

Ankle-brachial index improved significantly from 0.29 ±0.21 to 0.52 ±0.23 (p < 0.001) in 12 patients (75.0%) 3 months after the experimental therapy in group 1. In this group angiography showed the development of collateral vessels. Ischemic ulcers healed completely in 11 patients (68.75%). In group 2 the ABI did not improve in any patient; moreover the complete healing of skin ulcers was not found in any of the patients of this group. Amputation was performed in 4 (25.0%) patients in group 1, and in 8 patients (50%) from group 2.

CONCLUSIONS

These data after 3-month follow-up indicate that intramuscular injection of MNC combined with gene therapy in patients with chronic CLI is safe, and a more feasible and effective method of treatment than the conventional therapy. However, both therapies are limited by the degree of microcirculation damage.

Quercetin protects against lipopolysaccharide-induced acute lung injury in rats through suppression of inflammation and oxidative stress

INTRODUCTION

Acute lung injury (ALI) is an acute inflammatory disease characterized by excess production of inflammatory factors in lung tissue. Quercetin, a herbal flavonoid, exhibits anti-inflammatory and anti-oxidative properties. This study was performed to assess the effects of quercetin on lipopolysaccharide (LPS)-induced ALI.

MATERIAL AND METHODS

Sprague-Dawley rats were randomly divided into 3 groups: the control group (saline alone), the LPS group challenged with LPS (Escherichia coli 026:B6; 100 µg/kg), and the quercetin group pretreated with quercetin (50 mg/kg, by gavage) 1 h before LPS challenge. Bronchoalveolar lavage fluid (BALF) samples and lung tissues were collected 6 h after LPS administration. Histopathological and biochemical parameters were measured.

RESULTS

The LPS treatment led to increased alveolar wall thickening and cellular infiltration in the lung, which was markedly prevented by quercetin pretreatment. Moreover, quercetin significantly (p < 0.05) attenuated the increase in the BALF protein level and neutrophil count and lung wet/dry weight ratio and myeloperoxidase activity in LPS-challenged rats. The LPS exposure evoked a 4- to 5-fold rise in BALF levels of tumor necrosis factor-α and interleukin-6, which was significantly (p < 0.05) counteracted by quercetin pretreatment. Additionally, quercetin significantly (p < 0.05) suppressed the malondialdehyde level and increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in the lung of LPS-treated rats.

CONCLUSIONS

Quercetin pretreatment effectively ameliorates LPS-induced ALI, largely through suppression of inflammation and oxidative stress, and may thus have therapeutic potential in the prevention of this disease.

Potential drug-drug interactions in hospitalized patients with chronic heart failure and chronic obstructive pulmonary disease

INTRODUCTION

Polypharmacy is common in patients with chronic heart failure (HF) and/or chronic obstructive pulmonary disease (COPD), but little is known about the prevalence and significance of drug-drug interactions (DDIs). This study evaluates DDIs in hospitalized patients.

MATERIAL AND METHODS

We retrospectively screened medical charts over a 6-month period for diagnosis of chronic HF and/or COPD. Potential DDIs were evaluated using Lexi-Interact software.

RESULTS

Seven hundred and seventy-eight patients were included in the study (median age 75 years, 61% men). The median number of drugs on admission and discharge was 6 (interquartile range (IQR) 4-9) and 7 (IQR 5-), respectively (p = 0.10). We recorded 6.5 ±5.7 potential DDIs per patient on admission and 7.2 ±5.6 on discharge (p = 0.2). From admission to discharge, type-C and type-X potential DDIs increased (p < 0.05 for both). Type X interactions were rare (< 1%), with the combination of a β-blocker and a β2 agonist being the most common (64%). There were significantly more type-C and type-D potential DDIs in patients with chronic HF as compared to patients with COPD (p < 0.001). Patients with concomitant chronic HF and COPD had more type-C and type-X potential DDIs when compared to those with individual disease (p < 0.005). An aldosterone antagonist and ACE inhibitor/ARB were prescribed to 3% of chronic HF patients with estimated glomerular filtration rate < 30 ml/(min × 1.73 m(2)).

CONCLUSIONS

The DDIs are common in patients with chronic HF and/or COPD, but only a few appear to be of clinical significance. The increase in potential DDIs from admission to discharge may reflect better guideline implementation rather than poor clinical practice.

C-reactive protein and serum amyloid a overexpression in lung tissues of chronic obstructive pulmonary disease patients: a case-control study

BACKGROUND

Although researchers have consistently demonstrated systemic inflammation in chronic obstructive pulmonary disease (COPD), its origin is yet unknown. We aimed to compare the lung bronchial and parenchymal tissues as potential sources of major acute-phase reactants in COPD patients and resistant smokers.

METHODS

Consecutive patients undergoing elective surgery for suspected primary lung cancer were considered for the study. Patients were categorized as COPD or resistant smokers according to their spirometric results. Lung parenchyma and bronchus sections distant from the primary lesion were obtained. C-reactive protein (CRP) and serum amyloid A (SAA1, SAA2 and SAA4) gene expressions were evaluated by RT-PCR. Protein levels were evaluated in paraffin embedded lung tissues by immunohistochemistry and in serum samples by nephelometry.

RESULTS

Our study included 85 patients with COPD and 87 resistant smokers. In bronchial and parenchymal tissues, both CRP and SAA were overexpressed in COPD patients. In the bronchus, CRP, SAA1, SAA2, and SA4 gene expressions in COPD patients were 1.89-fold, 4.36-fold, 3.65-fold, and 3.9-fold the control values, respectively. In the parenchyma, CRP, SAA1, and SAA2 gene expressions were 2.41-, 1.97-, and 1.76-fold the control values, respectively. Immunohistochemistry showed an over-stained pattern of these markers on endovascular cells of COPD patients. There was no correlation with serum protein concentration.

CONCLUSIONS

These results indicate an overexpression of CRP and SAA in both bronchial and parenchymal tissue in COPD, which differs between both locations, indicating tissue/cell type specificity. The endothelial cells might play a role in the production of theses markers.