Endothelial nitric oxide synthase gene variants contribute to oxidative stress in COPD

Interactions of the eNOS and ACE genes and cigarette smoking in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a complex disorder with unexplained heritability. Interactions of genetic and environmental factors are thought to be crucial in COPD. So, we aim to examine interactions of the endothelial nitric oxide synthase (eNOS) and angiotensin converting enzyme (ACE) genes and cigarette smoking in COPD.

Methods

The eNOS G 894T and ACE ID variants were analyzed in 122 COPD patients and 200 controls from Serbia. The effect of the variants on COPD was assessed by logistic regression. Interactions between eNOS, ACE and cigarette smoking in COPD were evaluated using a case-control model. Interaction between the genes was analyzed in silico.

Results

No effect of the eNOS G 894T and ACE ID variants on COPD was found in our study. Gene-gene interaction between the eN OS T T and A CE D was identified (p=0.033) in COPD. The interaction is realized within the complex network of biochemical pathways. Gene-environment interactions between the eNOS T and cigarette smoking (p=0.013), and the ACE II and cigarette smoking (p=0.009) were detected in COPD in our study.

Conclusions

This is the first research to reveal interactions of the eNOS and ACE genes and cigarette smoking in COPD progressing our understanding of COPD heritability and contributing to the development of appropriate treatments.

Nitric Oxide: The Missing Factor in COVID-19 Severity?

Coronavirus disease 2019 (COVID-19) is a contagious respiratory and vascular disease that continues to spread among people around the world, mutating into new strains with increased transmission rates, such as the delta variant. The scientific community is struggling to discover the link between negative COVID-19 outcomes in patients with preexisting conditions, as well as identify the cause of the negative clinical patient outcomes (patients who need medical attention, including hospitalization) in what seems like a widespread range of COVID-19 symptoms that manifest atypically to any preexisting respiratory tract infectious diseases known so far. Having successfully developed a nutritional formulation intervention based on nitrate, a nitric oxide precursor, the authors hypothesis is that both the comorbidities associated with negative clinical patient outcomes and symptoms associated with COVID-19 sickness are linked to the depletion of a simple molecule: nitric oxide.

Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD.

Impact of cathepsin D activity and C224T polymorphism (rs17571) on chronic obstructive pulmonary disease: correlations with oxidative and inflammatory markers

BACKGROUND

Cathepsin D (CTSD) is an aspartyl proteinase that plays an important role in protein degradation, antigen processing and apoptosis. It has been associated with several pathologies such as cancer, Alzheimer's disease and inflammatory disorders. Its function in lung diseases remains, however, controversial. In the current study, we determined CTSD activity in serum of patients with chronic obstructive pulmonary disease (COPD) and evaluated the correlations between this proteinase and inflammatory and oxidative parameters. We also investigated the impact of a CTSD C224T polymorphism on enzyme activity and clinicopathological parameters.

METHODS

Our population included 211 healthy controls and 138 patients with COPD. CTSD activity, MMPs (-1/-7/-12), cytokines (IL-6, TNF-α), malondialdehyde (MDA), nitric oxide and peroxynitrite levels were measured in patients and controls using standard methods. Genotyping of CTSD C224T polymorphism was determined using PCR-RFLP.

RESULTS

Our results showed an increased CTSD activity in COPD patients compared to healthy controls (4.87 [3.99-6.07] vs. 3.94 [2.91-5.84], respectively, p < 0.001). COPD smokers presented also a higher CTSD activity when compared to nonsmokers (4.91[3.98-6.18] vs. 4.65[4.16-5.82], respectively, p = 0.01), while no differences were found when subjects were compared according to their GOLD stages. The activity of this proteinase was not dependent on the C224T polymorphism because we did not found any influence of this SNP on proteinase activity among patients and controls. Furthermore, our data provide the first evidence of the interrelationships between CTSD activity and both MMPs and TNF-α levels (MMP-1[r = - 0.4; p = 0.02], MMP-7[r = 0.37; p = 0.04], MMP-12[r = 0.43; p = 0.02], TNF-α [r = 0.89, p = 0.001]) in COPD smokers. There were no correlations, however, between CTSD activity and oxidative stress parameters in controls and patients.

CONCLUSION

Our findings suggest that CTSD could be a relevant marker for COPD disease. Alteration of CTSD activity may be related to increased MMPs and TNF-α levels, particularly in COPD smokers.

Evaluation of Naringenin as a Promising Treatment Option for COPD Based on Literature Review and Network Pharmacology

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease characterized by incompletely reversible airflow limitation and seriously threatens the health of humans due to its high morbidity and mortality. Naringenin, as a natural flavanone, has shown various potential pharmacological activities against multiple pathological stages of COPD, but available studies are scattered and unsystematic. Thus, we combined literature review with network pharmacology analysis to evaluate the potential therapeutic effects of naringenin on COPD and predict its underlying mechanisms, expecting to provide a promising tactic for clinical treatment of COPD.

The -786 T/C polymorphism of NOS3 gene is a susceptibility marker of COPD among Tunisians that correlates with nitric oxide levels and airflow obstruction

OBJECTIVE

The goal of this study was to examine the role of G894T (rs1799983), -786T/C (rs3918161) and a 27 bp variable number of tandem repeats (VNTR) 4B/4A of NOS3 gene on the risk and severity of COPD.

METHODS

The study included 194 controls and 138 COPD patients. NOS3 G894T, -786T/C and 4B/4A variants were determined by PCR analysis based on the banding pattern on gel electrophoresis. Pulmonary function was evaluated using body plethysmography. The levels of nitric oxide, peroxynitrite and lipid peroxides (T-BARS) were determined using spectrophotometric methods. Levels of serum IL-6, TNF-α and TGFβ were determined by ELISA.

RESULTS

In case-control studies, both G894T and -786T/C variants were associated with COPD risk. A significantly increased risk of COPD was found with the NOS3894T and -786C alleles (OR:1.93, P=0.001; OR:2.05, P=0.001, respectively). No significant impact of the G894T and 4B/4A SNPs was found on COPD severity, while a significant correlation was retrieved between the NOS3 -786T/C variation and advanced stages (OR: 1.89, P=0.009). In addition, COPD patients with the -786CC genotype exhibited lower FEV1% values in comparison to -786TT carriers (48±3.28 vs. 58.06±2.3, P=0.01, respectively). Patients having the -786CC genotype presented lower plasma levels of nitric oxide and higher T-BARS in comparison to -786TT individuals (173.22±13.4 vs. 228.93±16.8, P=0.01; 1.8±0.15 vs. 1.22±0.15, P=0.01, respectively).

CONCLUSION

This study provides the first evidence for the association of G894T, -786T/C variants with COPD risk among Tunisians. The -786T/C variation correlates with enhanced airflow limitation. This finding could be related to altered levels of nitric oxide and enhanced lipid peroxides among patients carrying the -786CC genotype.

Expression of Nitric Oxide Synthase Isoenzyme in Lung Tissue of Smokers with and without Chronic Obstructive Pulmonary Disease

Background:

It has been demonstrated that only 10%–20% cigarette smokers finally suffer chronic obstructive pulmonary disease (COPD). The underlying mechanism of development remains uncertain so far. Nitric oxide (NO) has been found to be closely associated with the pathogenesis of COPD, the alteration of NO synthase (NOS) expression need to be revealed. The study aimed to investigate the alterations of NOS isoforms expressions between smokers with and without COPD, which might be helpful for identifying the susceptibility of smokers developing into COPD.

Methods:

Peripheral lung tissues were obtained from 10 nonsmoker control subjects, 15 non-COPD smokers, and 15 smokers with COPD. Neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS) mRNA and protein levels were measured in each sample by using real-time polymerase chain reaction and Western blotting.

Results:

INOS mRNA was significantly increased in patients with COPD compared with nonsmokers and smokers with normal lung function (P < 0.001, P = 0.001, respectively). iNOS protein was also higher in COPD patients than nonsmokers and smokers with normal lung function (P < 0.01 and P = 0.01, respectively). However, expressions of nNOS and eNOS did not differ among nonsmokers, smokers with and without COPD. Furthermore, there was a negative correlation between iNOS protein level and lung function parameters forced expiratory volume in 1 s (FEV₁) (% predicted) (r = −0.549, P = 0.001) and FEV₁/forced vital capacity (%, r = −0.535, P = 0.001).

Conclusions:

The expression of iNOS significantly increased in smokers with COPD compared with that in nonsmokers or smokers without COPD. The results suggest that iNOS might be involved in the pathogenesis of COPD, and may be a potential marker to identify the smokers who have more liability to suffer COPD.

Alteration in systemic markers of oxidative and antioxidative status in Tunisian patients with asthma: relationships with clinical severity and airflow limitation

OBJECTIVE

This study aims to determine the systemic oxidant-antioxidant status in Tunisian patients with asthma.

METHODS

We evaluated the levels of malondialdehyde (MDA) as thiobarbituric acid complexes, total protein carbonyls (PCs) and advanced oxidation protein products (AOPP). The levels of total thiols, protein sulfhydryls, glutathione (GSH), together with hydrogen peroxide, ascorbic acid, iron and total antioxidant status (TAS) were colorimetrically estimated. Glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activities were assessed in plasma and erythrocytes by spectrophotometry. We also determined the levels of nitric oxide (NO) and peroxynitrite in plasma from asthmatic patients and healthy controls. The volume of fractionated exhaled NO (FeNO) was evaluated by the Medisoft HypAir method. Estimation of DNA damage was determined using the comet assay.

RESULTS

Asthmatic patients showed increased levels of MDA in comparison to healthy controls (p < 0.001), while no significant difference was found in protein carbonyls (p = 0.79) and AOPP (p = 0.98). Patients with asthma also had significantly lower levels of total thiols (355.9 ± 15.72 versus 667.9 ± 22.65, p < 0.001), protein sulfhydryls (333.99 ± 16.41 versus 591.95 ± 24.28, p < 0.001) and glutathione (p < 0.001). They also showed decreased GSH-Px activity (p < 0.001), whereas no significant differences in measurements of catalase and SOD enzyme activities were observed between the two groups (respectively, p = 0.06 and p = 0.55). In addition, ascorbic acid and nitric oxide levels were decreased in asthmatics in comparison to controls (p < 0.01).

CONCLUSIONS

Our findings highlight that oxidative stress and defective anti-oxidative status are major alterations in Tunisian patients with asthma.

Endothelial nitric oxide synthase gene polymorphism relationship with semen parameters and oxidative stress in infertile oligoasthenoteratozoospermic men

OBJECTIVE

To assess endothelial nitric oxide synthase (eNOS) gene polymorphism relationship with semen parameters and oxidative stress in infertile oligoasthenoteratozoospermic (OAT) men.

MATERIALS AND METHODS

Three hundred subjects were divided into healthy fertile men (n = 80) and infertile OAT men (n = 220). They were subjected to history taking, clinical examination, and semen analysis in addition to malondialdehyde and glutathione peroxidase estimation in seminal plasma. Polymorphisms of eNOS G894T and T786C genotypes in peripheral blood were identified by the polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

Comparing infertile OAT men with fertile controls, eNOS genotype G894T demonstrated prevalence of 36.8% vs 50% for wild type (GG), 35.0% vs 47.5% for heterozygous type (GT), and 28.2% vs 2.5% for mutant homozygous type (TT). Compared with GG homozygotes, carriers with A allele exhibited >1.716-fold increased risk of OAT occurrence. Comparing infertile OAT men with fertile controls, eNOS genotype T786C demonstrated prevalence of 37.3% vs 51.3% for wild type (TT), 32.7% vs 45% for heterozygous type (TC), and 30% vs 3.7% for mutant type (CC) with significant differences. Compared with TT homozygotes, carriers with C allele exhibited >1.769-fold increased risk of OAT occurrence. G894T and T786C genotypes demonstrated significant negative correlation with sperm count, total sperm motility, sperm normal forms, and seminal glutathione peroxidase, and significant positive correlation with seminal malondialdehyde. G894T genotype demonstrated significant positive correlation with T786C genotype.

CONCLUSION

There is a significant relationship between eNOS genotypes T786C, G894T polymorphisms with decreased sperm parameters and increased seminal oxidative stress.

Increased oxidative stress and altered levels of nitric oxide and peroxynitrite in Tunisian patients with chronic obstructive pulmonary disease: correlation with disease severity and airflow obstruction

This study was aimed to evaluate the oxidant-antioxidant imbalance in the pathogenesis of chronic obstructive pulmonary disease (COPD) in Tunisians. We assessed 16 parameters related to the oxidative status that include malondialdehyde (MDA), total protein carbonyls (PCs), and advanced oxidation protein products (AOPP). We also examined the activity of glutathione peroxydase (GSH-Px), catalase, and superoxide dismutase (SOD) in the plasma and erythrocytes. Levels of total thiols, reduced glutathione (GSH), total antioxidant status (TAS), hydrogen peroxide, ascorbic acid, iron, and protein sulfhydryls were determined using spectrophotometry. We also evaluated the level of nitric oxide (NO) and peroxynitrite in plasma from COPD patients and healthy controls. Estimation of DNA damage was determined using the comet assay. Pulmonary functional tests were performed by body plethysmography. Levels of MDA, PC, DNA damage, and AOPP were significantly increased while total thiols, GSH, and TAS were decreased in COPD patients. GSH-Px activity was higher in COPD patients while no difference was found for catalase and SOD. We also observed a lower level of NO and peroxynitrite in COPD patients. Decreased levels of peroxynitrite were found to correlate with disease progression, as well as with forced expiratory volume in 1 s/forced vital capacity among COPD patients. Multivariate analysis revealed that NO is associated with pathological pathways that help to predict patient outcome independently of the degree of airflow obstruction. These results indicate the presence of a systemic oxidative stress and highlight the importance of NO and peroxynitrite as major effectors in COPD development and airflow obstruction.

Gene polymorphisms and chronic obstructive pulmonary disease

The genetic component was suggested to contribute to the development of chronic obstructive pulmonary disease (COPD), a major and growing public health burden. The present review aims to characterize the evidence that gene polymorphisms contribute to the aetiology of COPD and related traits, and explore the potential relationship between certain gene polymorphisms and COPD susceptibility, severity, lung function, phenotypes, or drug effects, even though limited results from related studies lacked consistency. Most of these studies were association studies, rather than confirmatory studies. More large-sized and strictly controlled studies are needed to prove the relationship between gene polymorphisms and the reviewed traits. More importantly, prospective confirmatory studies beyond initial association studies will be necessary to evaluate true relationships between gene polymorphisms and COPD and help individualized treatment for patients with COPD.

Nitric oxide synthase polymorphisms, gene expression and lung function in chronic obstructive pulmonary disease

Background

Due to the pleiotropic effects of nitric oxide (NO) within the lungs, it is likely that NO is a significant factor in the pathogenesis of chronic obstructive pulmonary disease (COPD). The aim of this study was to test for association between single nucleotide polymorphisms (SNPs) in three NO synthase (NOS) genes and lung function, as well as to examine gene expression and protein levels in relation to the genetic variation.

Methods

One SNP in each NOS gene (neuronal NOS (NOS1), inducible NOS (NOS2), and endothelial NOS (NOS3)) was genotyped in the Lung Health Study (LHS) and correlated with lung function. One SNP (rs1800779) was also analyzed for association with COPD and lung function in four COPD case–control populations. Lung tissue expression of NOS3 mRNA and protein was tested in individuals of known genotype for rs1800779. Immunohistochemistry of lung tissue was used to localize NOS3 expression.

Results

For the NOS3 rs1800779 SNP, the baseline forced expiratory volume in one second in the LHS was significantly higher in the combined AG + GG genotypic groups compared with the AA genotypic group. Gene expression and protein levels in lung tissue were significantly lower in subjects with the AG + GG genotypes than in AA subjects. NOS3 protein was expressed in the airway epithelium and subjects with the AA genotype demonstrated higher NOS3 expression compared with AG and GG individuals. However, we were not able to replicate the associations with COPD or lung function in the other COPD study groups.

Conclusions

Variants in the NOS genes were not associated with lung function or COPD status. However, the G allele of rs1800779 resulted in a decrease of NOS3 gene expression and protein levels and this has implications for the numerous disease states that have been associated with this polymorphism.

Updates on the COPD gene list

A genetic contribution to develop chronic obstructive pulmonary disease (COPD) is well established. However, the specific genes responsible for enhanced risk or host differences in susceptibility to smoke exposure remain poorly understood. The goal of this review is to provide a comprehensive literature overview on the genetics of COPD, highlight the most promising findings during the last few years, and ultimately provide an updated COPD gene list. Candidate gene studies on COPD and related phenotypes indexed in PubMed before January 5, 2012 are tabulated. An exhaustive list of publications for any given gene was looked for. This well-documented COPD candidate-gene list is expected to serve many purposes for future replication studies and meta-analyses as well as for reanalyzing collected genomic data in the field. In addition, this review summarizes recent genetic loci identified by genome-wide association studies on COPD, lung function, and related complications. Assembling resources, integrative genomic approaches, and large sample sizes of well-phenotyped subjects is part of the path forward to elucidate the genetic basis of this debilitating disease.

Significance of bioinformatics in research of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease characterized by the progressive deterioration of pulmonary function and increasing airway obstruction, with high morality all over the world. The advent of high-throughput omics techniques provided an opportunity to gain insights into disease pathogenesis and process which contribute to the heterogeneity, and find target-specific and disease-specific therapies. As an interdispline, bioinformatics supplied vital information on integrative understanding of COPD. This review focused on application of bioinformatics in COPD study, including biomarkers searching and systems biology. We also presented the requirements and challenges in implementing bioinformatics to COPD research and interpreted these results as clinical physicians.

The 27-bp VNTR polymorphism in intron 4 of the human eNOS gene in healthy Singaporean Chinese, Indians, and Malays

Human endothelial nitric oxide synthase (eNOS) is one isoform of the nitric oxide synthases that are responsible for nitric oxide synthesis from L-arginine. The gene encoding eNOS contains a 27-bp VNTR polymorphism in intron 4. We report here for the first time the presence of a novel allele 3, which was absent in all other populations studied to date, in 1.7% each of Singaporean Indians and Malays. We also detected the presence of a novel genotype 3/5 in 3.4% each of Singaporean Indians and Malays. Allele 6, which was absent in Han Chinese from northern China and Taiwan and was also absent in Indians from the Indian subcontinent, was found in 2.1% of Singaporean Chinese and in 0.3% of Singaporean Indians.

CYP1A1, CYP1A2 and CYBA gene polymorphisms associated with oxidative stress in COPD

BACKGROUND

The genetic susceptibility to chronic obstructive pulmonary disease (COPD) depends on detoxification and antioxidant enzymes, which detoxify cigarette smoke reactive components that, otherwise, generate oxidative stress.

METHODS

In a case-control study of 346 subjects with and without COPD, we examined the polymorphisms 462Ile/Val, 3801T/C of CYP1A1, -3860G/A of CYP1A2 and -930A/G, 242C/T of CYBA individually or in combination and their contribution to oxidative stress markers by measuring malondialdehyde (MDA), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx).

RESULTS

COPD patients had significantly increased MDA concentration (p<0.001) and decreased CAT activity, GSH concentration, GPx activity (p< or =0.01). The patients were over-represented by the alleles 462Val, 3801C of CYP1A1 and -930G, 242C of CYBA (p<0.001, p=0.003, p=0.030 and p=0.031, respectively) and consequently the haplotypes of same alleles i.e. 462Val:3801C, 462Val:3801T and -930G:242C (p=0.048, p=0.016 and p=0.039, respectively). Similarly, CYP1A1 and CYP1A2 haplotypes, 462Val:3860G and 462Val:3801T:3860G were significantly over-represented (p=0.001 and p=0.003), respectively in patients. The same alleles-associated genotype-combinations between genes were more prevalent in patients. Of note, the genotypes, 462Ile/Val+Val/Val, 3801TC+CC of CYP1A1 and -930AG+GG of CYBA associated with increased MDA concentration (p=0.018, p=0.045 and p=0.017, respectively), decreased CAT activity (p<0.0001, p=0.080 and p<0.0001, respectively) and GSH concentration (p<0.0001, p=0.0002 and p=0.011, respectively) in patients.

CONCLUSION

The identified alleles, its haplotypes and the genotype-combination along with increased oxidative stress, signify the importance in susceptibility to COPD.

COX2 and p53 risk-alleles coexist in COPD

BACKGROUND

Cigarette smoke stimulates airway epithelial cells to release pro-inflammatory cytokines which influence various inflammation-related genes, including COX2, whereas p53 expression is known to alter in such a condition. Since both the genes share several common physiological functions including inflammation and oxidative stress, we investigated within gene and gene-gene interactions towards susceptibility to the disease.

METHOD

In a prospective gene-association study we conducted PCR-RFLP for genotyping the COX2 -765G/C and 8473T/C and p53 72Pro/Arg polymorphisms in 229 COPD patients and 147 healthy controls.

RESULTS

The -765GC+CC genotypes of COX2 and Pro/Pro+Pro/Arg genotypes of p53 were prevalent in patients with significant odds ratio, 2.05 and 2.30, respectively (p=0.001; p=0.009, respectively), as a consequence, the -765C and 72Pro alleles were prevalent (p<or=0.001). Individually, the 8473T/C polymorphism did not associate with the disease (p=NS), however, it did in the haplotype -765C:8473C, which was significantly higher in patients (p<0.0001). Based on its prevalence, the three alleles were identified as risk-alleles in patients. The combinations of the genotypes containing 3, 4 and 5 risk alleles of the 3 polymorphisms were significantly over-represented in patients, whereas, the genotypes combinations containing 0, 1 and 2 risk alleles were significantly higher in controls (p=0.0004). The pairwise gene-gene interactions validated prevalence of risk-alleles associated pairing of genotypes such as the Pro/Pro+ Pro/Arg with -765GC+-765CC in patients (p=0.01).

CONCLUSION

The prevalence of COX2 and p53 risk-alleles contributes towards susceptibility to the disease.

Short-term exposure to cigarette smoke induces endothelial dysfunction in small intrapulmonary arteries: analysis using guinea pig precision cut lung slices

The pathogenesis of cigarette smoke-induced pulmonary hypertension is not understood. We have previously shown that smoke rapidly and persistently, but discoordinately, upregulates gene expression of mediators that control vasoconstriction, vasoproliferation, and vasorelaxation in small intrapulmonary arteries. To investigate the possibility that smoke also induces endothelial dysfunction, a finding common to other forms of pulmonary hypertension, we exposed guinea pigs to smoke or air (control) daily for 2 wk and then prepared precision-cut lung slices. After exposure to endothelin-1, a vasoconstrictor, intra-acinar arteries in lung slices derived from smoke-exposed animals constricted more rapidly (greater constriction at a given concentration of endothelin) than did vessels from air-exposed animals. To examine relaxation responses, arteries were constricted with the vasoconstrictor U-46619 and then relaxed with progressively increasing doses of acetylcholine. Vessels from smokers had a delayed response to acetylcholine compared with vessels from controls. The NO synthase inhibitor N(G)-nitro-L-arginine methyl ester reduced relaxation in both control and smoke-exposed arteries, whereas the NO donor sodium nitroprusside increased relaxation of the smoke-exposed arteries, confirming that endothelial dysfunction with decreased effective NO production is present. These findings show that precision cut lung slices can be used to examine the physiological effects of cigarette smoke on intra-acinar pulmonary arteries and indicate that even relatively short-term exposure to smoke produces endothelial dysfunction with a resulting tendency to earlier constriction and later relaxation in cigarette smokers. These changes may be important in the development of pulmonary hypertension.

Radical generation and alterations of erythrocyte integrity as bioindicators of diagnostic or prognostic value in COPD?

Chronic obstructive pulmonary disease (COPD) has recently been viewed as an inflammation-dependent systemic disease. Oxidative modifications in the pulmonary microenvironment can result in a number of functional changes in pulmonary tissue as well as in the blood. Studies have been carried out to detect whether oxidatively modified molecules or cells could be considered possible markers of the disease. We hypothesize here that new insights into COPD could come from enzymes involved in deliberate radical generation (i.e., Nox and NOS family enzymes) as well as from alterations of erythrocyte integrity and function, which could become bioindicators of diagnostic or prognostic value in the near future.