Genetic influences on right ventricular systolic pressure (RVSP) in chronic obstructive pulmonary disease (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.

ACE gene polymorphism is associated with COPD and COPD with pulmonary hypertension: a meta-analysis

Purpose

Angiotensin-converting enzyme (ACE) gene I/D polymorphism has been studied in relation to the susceptibility to COPD and COPD with pulmonary hypertension (PH) with inconclusive results. We performed the first comprehensive meta-analysis to evaluate accurately the association between the ACE gene polymorphism and the risk of COPD.

Methods

Data were analyzed using odds ratios (ORs) and the corresponding 95% CIs to measure the strength of the models. Subgroup analyses were conducted by ethnicity and complication which referred to PH.

Results

In total, 15 studies (2,635 participants) were included in our study, of which four studies (288 participants) were for PH subgroup. The overall analysis results indicated that the ACE gene polymorphism was not associated with COPD susceptibility in all gene models. However, the ethnic subgroup analysis results indicated that ACE gene polymorphism was associated with Asians’ susceptibility to COPD (DD+DI vs II, OR=1.47, P=0.019, 95% CI: 1.07–2.02). Further, the overall results of the present study detected no statistical significance between ACE gene polymorphism and the risk of COPD with PH, but the homozygote variant (DD) increased the risk of PH in Asian COPD patients (DD vs ID+II, OR=2.05, P=0.05, 95% CI: 1.00–4.19).

Conclusion

The current study suggests that ACE polymorphism, particularly the homozygote variant (DD), might contribute to the risk of COPD and COPD with PH among Asians. Further studies with larger sample size and more ethnicities are expected to be conducted in the future to validate the results.

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.

Angiotensinogen gene M235T and angiotensin II-type 1 receptor gene A/C1166 polymorphisms in chronic obtructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) occurs irreversibly and is characterized by progressive airflow obstruction. Renin angiotensin system (RAS) has many different key enzymes and receptors that have a role for different systemic processes. We aimed to determine genotype and allele frequencies of angiotensinogen (AGT) M235T and angiotensin II-type 1 receptor (AT1-R) A/C1166 polymorphisms in patients with COPD. This study was performed on 56 unrelated COPD patients and 29 healthy subjects. DNA samples for each individual were isolated from peripheral blood by phenol/chloroform method, analyzed by polymerase chain reaction and enzymatic digestion methodologies. The distribution for each of AGT genotypes were 23.2% for MM (13), 75.0% for MT (42) and 1.8% for TT (1) in the COPD group; 37.9% for MM (11), 34.5% for MT (10) and 27.6% for TT (8) in the control group. The distribution of AGT genotypes was found significantly different between groups (X(2) = 18.604; df = 2; P = 0.000). The frequencies for each of the AT1-R genotypes were found as 53.6% for AA (30), 42.9% for AC (24), 3.6% for CC (2) in the COPD group; 55.2% for AA (16), 41.4% for AC (12) and 3.4% for CC (1) in the control group. The distribution of AT1-R genotypes did not change significantly between groups. Allele frequencies of interested genes were not significantly different between groups. We suggest that AGT polymorphism may play a role for the development of COPD. We believe these data can be served for large scale population genetics research, considering the frequency of AGT and AT1-R genes and alleles in COPD patients in the Turkish population.

Personalizing and targeting therapy for COPD: the role of molecular and clinical biomarkers

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by persistent airflow limitation. It is the third leading cause of death worldwide, and there are currently no curative strategies for this disease. Many factors contribute to COPD susceptibility, progression and exacerbations. These include cigarette smoking, environmental and occupational pollutants, respiratory infections and comorbidities. As the clinical phenotypes of COPD are so variable, it has been difficult to devise an individualized treatment plan for patients with this complex chronic disease. This review will highlight how potential clinical, inflammatory, genomic and epigenomic biomarkers for COPD could be used to personalize treatment, leading to improved disease management and prevention for our patients.