Association of IL-1beta and IL-1 receptor antagonist haplotypes with rate of decline in lung function in smokers

Exosome microRNA-125a-5p derived from epithelium promotes M1 macrophage polarization by targeting IL1RN in chronic obstructive pulmonary disease

BACKGROUND

The interplay between airway epithelium and macrophages plays a pivotal role in Chronic Obstructive Pulmonary Disease (COPD) pathogenesis. Exosomes, which transport miRNA cargo, have emerged as novel mediators of intercellular communication. MicroRNA-125a-5p (miR-125a-5p) has been implicated in macrophage polarization.This study aims to investigate the role of exosomal miR-125a-5p in the dysfunctional epithelium-macrophage cross-talk in cigarette smoke (CS)-induced COPD.

METHODS

In cell models, THP-1 monocytic cells were differentiated into macrophages (M0). Human bronchial epithelial cells treated with CS extract (CSE) were co-cultured with M0. Exosomes were isolated from culture media using commercial kits and characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Exosomes labeled with PKH26 red fluorescent cell linker kits were incubated with macrophages. Luciferase reporter assay was used to confirm the target gene of miR-125a-5p. In mouse experiments, inhibiting miR-125a-5p was utilized to examine its role in macrophage polarization. Furthermore, the underlying mechanism was explored.

RESULTS

In vitro results indicated that CSE treatment led to upregulation of miR-125a-5p in HBE cells, and exosomes contained miR-125a-5p. PKH26-labeled exosomes were internalized by macrophages. Co-culture experiments between bronchial epithelial cells and miR-125a-5p mimic resulted in significant increase in M1 macrophage markers (TNF-α, iNOS-2, IL-1β) and decrease in M2 markers (IL-10 and Arg-1). In COPD mouse models, miR-125a-5p inhibitor reduced levels of TNF-α, IL-1β, and IL-6. Luciferase assays revealed that miR-125a-5p inhibitors enhanced the relative luciferase activity of IL1RN. Mechanistic experiments demonstrated that HBE-derived exosomes transfected with miR-125a-5p mimics promoted upregulation of MyD88, TRAF6, p65, iNOS-2, and downregulation of Arg-1.

CONCLUSION

This study suggests that exosomal miR-125a-5p may act as a mediator in the cross-talk between airway epithelium and macrophage polarization in COPD. Exosomal miR-125a-5p targeting IL1RN may promote M1 macrophage polarization via the MyD88/NF-κB pathway.

Th22 Cells/IL-22 Serves as a Protumor Regulator to Drive Poor Prognosis through the JAK-STAT3/MAPK/AKT Signaling Pathway in Non-Small-Cell Lung Cancer

The interaction of immune cells and cytokines in the tumor microenvironment affects the development and prognosis of tumors with an unclear potential regulatory mechanism. Recent studies have elucidated the protumor role of Th22 cells and its lineage-specific cytokine IL-22 in different human cancers. The present study is aimed at investigating the biological effect of Th22 cells/IL-22 and its molecular mechanism in the pathogenesis process of non-small-cell lung cancer (NSCLC). It was initially found that Th22 cells were enriched in the peripheral blood of NSCLC patients. The level of Th22 cells in peripheral blood mononuclear cells (PBMCs) was positively correlated with the TNM stage, lymph node metastasis, and clinical tumor biomarkers. Furthermore, IL-22 not only antagonized the apoptosis inducing and cell cycle arresting effect by chemotherapy and molecular targeted drugs on NSCLC cell lines but also promoted tumor cell proliferation and tumor tissue growth. Moreover, IL-22 activated the JAK-STAT3/MAPK/AKT signaling pathway, both in vitro and in vivo. Conclusively, the present results confirm that Th22 cells/IL-22 may serve as a negative immune regulator in lung cancer.

Association of IL1 beta gene polymorphism and allograft functions in renal transplant recipients :a case control study from Kashmir Valley

BACKGROUND

Cytokines have been found to be the important mediators during renal graft outcome. Therefore, we designed this study to investigate the role of recipients' IL-1 β promoter (-511) and IL-1 β exon-5 (+3954) polymorphisms with the risk of graft outcome.

METHODOLOGY

We enrolled one hundred recipients of living-related renal transplants together with the age and sex matched controls from the healthy population not having any renal abnormality for this study. Genotype frequencies of the IL-1 β promoter (-511) and IL-1 β exon-5 (+3954) were analyzed using PCR-RFLP technique.

RESULTS

Our results revealed significant differences in the healthy control group and patient group in IL 1β +3954 (p < 0.001). The frequency of variant type TT genotype was higher in RE group as compared to SGF and showed 4 fold risk of rejection (OR = 4.54, p < 0.069) although p value was not significant. The frequency of wild type CC genotype and CT was not significant (p value 0.89 and 0.74 respectively).

CONCLUSION

Our findings suggest that there is a prevalence of mutated allele of IL-1 gene cluster in our population, which may be responsible for renal dysfunction.

Role of oxidative stress & transient receptor potential in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) affect millions of people worldwide and is known to be one of the leading causes of death. The highly sensitive airways protect themselves from irritants by cough and sneeze which propel endogenous and exogenous substances to minimize airway noxious effects. One noxious effect of these substances is activation of peripheral sensory nerve endings of nociceptor neurons innervating these airways lining thus transmitting dangerous signals from the environment to the central nervous system (CNS). Nociceptor neurons include transient receptor potential (TRP) ion channels, especially the vanilloid and ankyrin subfamilies, TRPV1/A1 which can be activated by noxious chemical challenges in models of airways disease. As oxidative stress may activate airways sensory neurons and contribute to COPD exacerbations we sought to review the role that TRP channel activation by oxidative signals may have on airway responses. It would be prudent to target the TRP channels with antagonists and lower systemic oxidative stress with agents that can modulate TRP expression and boost the endogenous levels of antioxidants for treatment and management of COPD.

Associations of interleukin-1 gene cluster polymorphisms with C-reactive protein concentration and lung function decline in smoking-induced chronic obstructive pulmonary disease

OBJECTIVE

We reported association of haplotypes formed by IL-1b (IL1B)-511C/T (rs16944) and a variable number of tandem repeats (rs2234663) in intron 3 of IL-1 receptor antagonist (IL1RN) with rate of lung function decline in smoking-induced COPD. The aim of current study was to further investigate this association.

METHODS

We genotyped an additional 19 polymorphisms in IL1 cluster (including IL1A, IL1B and IL1RN) in non-Hispanic whites who had the fastest (n = 268) and the slowest (n = 292) decline of FEV1% predicted in the same study. We also analyzed the association of all 21 polymorphisms with serum CRP levels.

RESULTS

None of 21 polymorphisms showed significant association with rate of decline of lung function or CRP levels after adjusting for multiple comparisons. Before adjusting for multiple comparisons, only IL1RN_19327 (rs315949) showed significant association with lung function decline (P = 0.03, additive model). The frequencies of genotypes containing the IL1RN_19327A allele were 71.9% and 62.2%, respectively in the fast and slow decline groups (P = 0.02, odds ratio = 1.6, 95% confidence interval = 1.1-2.3); the IL1B_5200 (rs1143633) and rs2234663 in IL1RN were associated with serum CRP levels (P=0.04 and 0.03, respectively).

CONCLUSIONS

No single marker was significantly associated with either rate of lung function decline or serum CRP levels.

A functional polymorphism in the interleukin-1beta and severity of nicotine dependence in male schizophrenia: a case-control study

Previous studies have shown that the functional 511C/T polymorphism in the IL-1beta-gene may be implicated in the susceptibility for schizophrenia. Moreover, recent studies suggested that IL-1 participates in the progression of lung disease in smokers, which are overrepresented in schizophrenia. We aimed to investigate the possible relationship between the IL-1beta-511C/T polymorphism and smoking behavior in schizophrenia versus healthy controls in a Chinese population. The IL-1beta-511C/T polymorphism was genotyped in 638 male patients with chronic schizophrenia (smoker/never-smoker = 486/152) and 469 male controls (smoker/never-smoker = 243/226). The cigarettes smoked per day, the Heaviness of Smoking Index (HSI) and the Fagerstrom Test for nicotine dependence (FTND) were assessed. Patients were also rated on the Positive and Negative Syndrome Scale (PANSS). The results showed no significant differences in genotype and allele distribution between patients and controls, and between smokers and never-smokers in either the patient or control group. However, in patients, smokers with the C/C genotype had significantly higher HSI (p < 0.005) and FTND (p < 0.05) scores than smokers with the T/T genotype, without significant differences in controls. Furthermore, there was a linear positive correlation between the number of C alleles and the HSI (p < 0.005) in patients. Our findings suggest that the IL-1beta-511C/T polymorphism may not be related to schizophrenia or smoking status in Chinese individuals, but may affect the severity of nicotine dependence among male smokers with schizophrenia.

Role of the inflammasome-caspase1/11-IL-1/18 axis in cigarette smoke driven airway inflammation: an insight into the pathogenesis of COPD

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory airway disease often associated with cigarette smoke (CS) exposure. The disease is increasing in global prevalence and there is no effective therapy. A major step forward would be to understand the disease pathogenesis. The ATP-P2X7 pathway plays a dominant role in murine models of CS induced airway inflammation, and markers of activation of this axis are upregulated in patients with COPD. This strongly suggests that the axis could be important in the pathogenesis of COPD. The aim of this study was to perform a detailed characterisation of the signalling pathway components involved in the CS-driven, P2X7 dependent airway inflammation.

METHODS

We used a murine model system, bioassays and a range of genetically modified mice to better understand this complex signalling pathway.

RESULTS

The inflammasome-associated proteins NALP3 and ASC, but not IPAF and AIM2, are required for CS-induced IL-1β/IL-18 release, but not IL-1α. This was associated with a partial decrease in lung tissue caspase 1 activity and BALF neutrophilia. Mice missing caspase 1/11 or caspase 11 had markedly attenuated levels of all three cytokines and neutrophilia. Finally the mechanism by which these inflammatory proteins are involved in the CS-induced neutrophilia appeared to be via the induction of proteins involved in neutrophil transmigration e.g. E-Selectin.

CONCLUSION

This data indicates a key role for the P2X7-NALP3/ASC-caspase1/11-IL-1β/IL-18 axis in CS induced airway inflammation, highlighting this pathway as a possible therapeutic target for the treatment of COPD.

Association between the IL1B, IL1RN polymorphisms and COPD risk: a meta-analysis

The interleukin-1 (IL-1) gene polymorphisms have been implicated in chronic obstructive pulmonary disease (COPD) risk, but results are controversial. We aimed to conduct a meta-analysis to address this issue. Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association. The meta-analysis revealed no association between the IL1B (−511), (−31), (+3954) polymorphisms and COPD risk. However, stratification by ethnicity indicated that the T allele carriers of the IL1B (−511) polymorphism and the C allele carriers of the IL1B (−31) variant were associated with an increased risk for developing COPD in East Asians (OR = 1.61, 95% CI: 1.13–2.31, P_z = 0.009 and OR = 1.55, 95% CI: 1.14–2.11, P_z = 0.006, respectively). The meta-analysis revealed a significant association between the IL1RN (VNTR) polymorphism and COPD risk in all study subjects and East Asians under homozygote model (22 vs. LL: OR = 3.16, 95% CI: 1.23–8.13, P_z = 0.017 and OR = 3.20, 95% CI: 1.13–9.12, P_z = 0.029, respectively). Our meta-analysis suggests that the IL1B (−511), (−31) and IL1RN (VNTR) polymorphisms are associated with COPD risk in East Asians. There is no association between the IL1B(+3954) polymorphism and COPD risk. Further studies should be performed in other ethnic groups besides East Asians.

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.

High risk association of IL-1 receptor antagonist (IL-1RN) VNTR polymorphism with asthma in a North Indian population: a pilot study

BACKGROUND

A pilot case-control study was conducted to evaluate the role of IL-1 receptor antagonist (IL-1RN) VNTR penta-allelic polymorphism in asthma that has been associated with various inflammatory diseases worldwide. This is the first case-control study conducted in India, investigating the role of IL-1RN VNTR polymorphism in asthma pathogenesis.

METHODS

A case-control study was performed with a total of 824 adult subjects, inducting 410 asthma patients and 414 healthy controls from North India. The genotypes were identified by polymerase chain reaction.

RESULTS

Statistical analysis for the IL-1RN VNTR polymorphism revealed that the IL-1RN(*)2 allele was significantly associated with asthma with OR=1.45, 95% CI (1.15-1.85) and p=0.001. The IL-1RN(*)2/2 genotype posed a risk towards asthma with OR=1.66, 95% CI (0.97-2.86) and p=0.048. Most of the phenotypic traits were significantly associated with the disease.

CONCLUSIONS

IL-1RN(*)2 allele is a high risk factor for asthma in the studied North Indian population.

Association of cytokine gene polymorphisms in patients with chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a major health problem. The disease is driven by abnormal inflammatory reactions in response to inhaled particles and fumes. Therefore, inflammatory mediators are postulated to be of distinct importance. Keeping in view of the above facts; we investigate the role of polymorphisms of cytokine genes in the genetic predisposition of COPD.

METHODS

In this present case-control study, the allele and genotype distributions of IL1B, IL1RN, TNF-α, and IL4 were studied in COPD patients (N=204) and healthy individuals (N=208). Genomic DNA was obtained by whole blood and genotyping was carried out by a polymerase chain reaction (PCR) based Restriction Fragment Length Polymorphism technique.

RESULTS

Genotype IL1RN*2/IL1RN*2 was identified as protective for male COPD, its frequency being 8.7% in COPD patients and 14.6% in healthy subjects (p=0.017; OR=0.53), but IL1RN*1/IL1RN*2 turned out to be a risk factor for females COPD. No significant differences were found between the groups of COPD patients and healthy subjects concerning the genotype frequencies of the polymorphisms T (-511) C of IL1B and 70bp VNTR of IL-4. Genotype GA of the TNF-α polymorphism G (-308) A was more common in the COPD patients than in the controls (20.5% vs.14.4%; p=0.107), and allele A was significantly associated with COPD patients (p=0.023; OR=0.65).

CONCLUSION

IL-1RN *2 allele appears to be significantly associated with the COPD female patients and TNF-α-308A allele is a risk factor for the development of COPD.

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.

Association of IL-1β -511 polymorphism with severe veno-occlusive disease in pediatric-matched allogeneic hematopoietic stem cell transplantation

Single nucleotide polymorphisms (SNPs) of the interleukin 1 (IL-1) family have been implicated in acute graft-versus-host disease and mortality postallogeneic hematopoietic stem cell transplantation (HSCT) in adults. Hepatic veno-occlusive disease (VOD) is a well-known complication of HSCT and can result in an increased risk of mortality. In this study, we sought to investigate the association of both patient and donor genotypes at the IL-1β -511 cytidine/thymidine (C/T) polymorphic site with hepatic VOD and mortality in an exclusive pediatric cohort undergoing matched myeloablative allogeneic HSCT. Donor TT genotype was associated with higher cumulative incidence of grade III-IV hepatic VOD at 3 months after transplantation relative to donor CT and CC genotypes (25±13.1% in TT, 2.9±2.9% in CT, and 3.6±3.6% in CC; P=0.024). Neither recipient nor donor IL-1β -511 single nucleotide polymorphisms genotypes were associated with mortality or relapse. Our findings suggest that donor, rather than host, genotype at the IL-1β -511 polymorphic site may associate with higher risk for severe VOD after matched allogeneic HSCT. Our findings challenge the assumption that host factors are exclusively responsible for VOD and suggest a novel role for the donor inflammasome pathway in inducing injury and microvascular disease after HSCT, which merits further study in a larger cohort analysis.

Role of P2X7 Receptors in Release of IL-1β: A Possible Mediator of Pulmonary Inflammation

Extracellular ATP is a signaling molecule which plays an important role in alerting the immune system in case of any tissue damage. Recent studies show that binding of ATP to the ionotropic P2X7 receptor of inflammatory cells (macrophages and monocytes) will induce caspase 1 activation. Stimulation of caspase 1 activity results in maturation and release of IL-1β in the inflammasome in Chronic Obstructive Pulmonary Disease (COPD) patients. COPD is an inflammatory disease characterized by emphysema and/or chronic bronchitis and is mostly associated with cigarette smoking. It is one of the leading causes of death in humans and there is currently no medication to stop the progression of disease. A deeper understanding of the mechanism by which the P2X7 receptor triggers IL-1β maturation and release, may open new opportunities for the treatment of inflammatory diseases such as COPD.

Genetics of COPD

Previous family studies suggested that genetic variation contributes to COPD susceptibility. The only gene proven to influence COPD susceptibility is SERPINA1, encoding α1-antitrypsin. Most studies on COPD candidate genes except SERPINA1, have not been consistently replicated. However, longitudinal studies of decline in lung function, meta-analyses of candidate gene studies, and family-based linkage analyses suggested that variants in EPHX1, GST, MMP12, TGFB1, and SERPINE2 were associated with susceptibility to COPD. A genome-wide association (GWA) study has recently demonstrated that CHRNA3/5 in 15q25 was associated with COPD compared with control smokers. It was of interest that the CHRNA3/5 locus was associated with nicotine dependence and lung cancer as well. The associations of HHIP on 4q31 and FAM13A on 4q22 with COPD were also suggested in GWA studies. Another GWA study has shown that BICD1 in 12p11 was associated with the presence or absence of emphysema. Although every genetic study on COPD has some limitations including heterogeneity in smoking behaviors and comorbidities, it has contributed to the progress in elucidating the pathogenesis of COPD. Future studies will make us understand the mechanisms underlying the polygenic disease, leading to the development of a specific treatment for each phenotype.

Effect of gene environment interactions on lung function and cardiovascular disease in COPD

Background:

The objective of this study was to determine if gene-environment interactions between cigarette smoking and interleukin-6 (IL6), interferon-γ (IFNG), interleukin-1β (IL1B), or interleukin-1 receptor antagonist (IL1RN) single nucleotide polymorphisms are associated with lung function decline and cardiovascular disease in chronic obstructive pulmonary disease (COPD).

Methods:

Single nucleotide polymorphisms (SNPs) in IL6, IFNG, IL1B, and IL1RN were genotyped in the Lung Health Study and correlated with rate of decline of forced expiratory volume in 1 second (FEV₁) over 5 years, baseline FEV₁, serum protein levels, cardiovascular disease, and interactions with smoking.

Results:

The IL6 rs2069825 single nucleotide polymorphism was associated with the rate of decline of prebronchodilator FEV₁ (P = 0.049), and was found to have a significant interaction (P = 0.004) with mean number of cigarettes smoked per day. There was also a significant interaction of IFNG rs2069727 with smoking on prebronchodilator (P = 0.008) and postbronchodilator (P =0.01) FEV_1. The IL6 polymorphism was also associated with cardiovascular disease in heterozygous individuals (P = 0.044), and was found to have a significant interaction with smoking (P = 0.024). None of the genetic variants were associated with their respective serum protein levels.

Conclusion:

The results suggest interactions of IL6 rs2069825 and IFNG rs2069727 single nucleotide polymorphisms with cigarette smoking on measures of lung function. The IL6 rs2069825 single nucleotide polymorphism also interacted with smoking to affect the risk of cardiovascular disease in COPD patients.

Asthma and chronic obstructive pulmonary disease: common genes, common environments?

Asthma and chronic obstructive pulmonary disease (COPD) show similarities and substantial differences. The Dutch hypothesis stipulated that asthma and COPD have common genetic and environmental risk factors (allergens, infections, smoking), which ultimately lead to clinical disease depending on the timing and type of environmental exposures (Postma and Boezen, Chest 2004;126:96S-104S). Thus, a particular group of shared genetic factors may lead to asthma when combined with specific environmental factors that are met at a certain stage in life, whereas combination with other environmental factors, or similar environmental factors at a different stage in life, will lead toward COPD. Multiple genes have been found for asthma and COPD. In addition to genes unique to these diseases, some shared genetic risk factors exist. Moreover, there are both common host risk factors and environmental risk factors for asthma and COPD. Here we put forward, based on the data available, that genes that affect lung development in utero and lung growth in early childhood in interaction with environmental detrimental stimuli, such as smoking and air pollution, are contributing to asthma in childhood and the ultimate development of COPD. Additional genes and environmental factors then drive specific immunological mechanisms underlying asthma, and others may contribute to the ultimate development of specific subtypes of COPD (i.e., airway disease with mucous hypersecretion, small airway disease, and emphysema). The genetic predisposition to the derailment of certain pathways may further help to define subgroups of asthma and COPD. In the end this may lead to stratification of patients by their genetic make-up and open new therapeutic prospects.

Proinflammatory cytokines in Egyptian elderly with chronic obstructive pulmonary disease

BACKGROUND

The pulmonary component of chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases.

HYPOTHESIS

The levels of the proinflammatory cytokines, interleukin 1 beta (IL-1β), tumor necrosis factor alfa (TNF-α), and C-reactive protein (CRP), in elderly patients suffering from COPD are increased.

SETTINGS AND DESIGN

A case control study involving 90 elderly participants from the outpatient clinics of Ain Shams University hospitals.

MATERIALS AND METHODS

The 90 subjects were subdivided into three equal groups ' group I (control), group II (patients with COPD), and group III (patients with COPD and cardiovascular complications). Comprehensive clinical assessment, pulmonary functions, and echocardiography were performed. The levels of IL-1β, TNF-α, and CRP were measured in the patients' serum and compared.

STATISTICAL ANALYSIS

SPSS (Statistical Package for Social Science) version 10.

RESULTS

IL1-βand CRP were significantly higher in the third group than the first group (P <0.05). There was a similar significant difference between the second and third group as regards IL1-βand CRP (P < 0.05). Positive significant correlation between CRP and TNF-α with stage of COPD according to FEV1 (P <0.05) were found.

CONCLUSIONS

Complicated cases of COPD had higher levels of IL1-β and CRP and the more severe the cases, the higher the levels of CRPand TNF-α.

Influence of interleukin-1 beta genetic polymorphism, smoking and alcohol drinking on the risk of non-small cell lung cancer

BACKGROUND

Non-small cell cancer (NSCLC) accounts for approximately 80% of all lung cancers. Reports suggested an association between the interleukin-1beta (IL-1beta) -31 and -511 gene loci and NSCLC, but few studies took into account the effect of smoking and/or alcohol drinking on the association.

METHODS

Two-hundred thirteen cases of NSCLC (aged 58.2 + or - 10.1) and 213 controls (aged 59.4 + or - 10.3y) were included in this research. Information about the smoking and drinking behaviors, dietary customs, and anamnesis were obtained from all subjects by questionnaires, and genomic DNA was extracted. IL-1beta -31 and -511 gene polymorphisms were detected using PCR-RFLP. The interactions between the genotypes and alcohol drinking/smoking were analyzed using multivariate logistic regression models.

RESULTS

(The T/T genotype and the T allele of the IL-1beta -31 gene were associated with higher incidence of NSCLC (P<0.05). For the IL-1beta -511 locus, no difference was found in different genotypes between the NSCLC and control groups. After the adjustment of confounding variables, such as age and gender, the binary logistic analysis showed a significant gene-environment interaction (P<0.05).

CONCLUSIONS

The IL-1beta -31T allele was positively associated with a risk of NSCLC, and the carriers of IL-1beta -31T/T or -511C/C would have a higher risk of suffering from NSCLC if they drank alcohol or smoke heavily.

Pharmacogenetics of chronic obstructive pulmonary disease: challenges and opportunities

Similar to other common chronic diseases, chronic obstructive pulmonary disease (COPD) is a heterogeneous disorder with multiple disease subtypes. Candidate gene studies have found genetic associations for COPD-related phenotypes that may be relevant for pharmacogenetics studies, including lung function decline and COPD exacerbations. However, few COPD pharmacogenetics studies have been completed. Most studies have focused on the role of variants in the beta(2)-adrenergic receptor gene on bronchodilator response, but the findings have been inconclusive. Candidate gene studies highlight the concept that genes for COPD susceptibility may also be relevant in COPD pharmacogenetics. Currently, there are no clinical applications of pharmacogenetics to COPD therapy, but the use of pharmacogenetics to determine initial smoking cessation therapy may be closer to clinical application.

Signal transduction pathways linking the activation of alveolar macrophages with the recruitment of neutrophils to lungs in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem. It is predicted by the World Health Organization to become the third most common cause of death and the fifth most common cause of disability in the world by 2020. COPD is a complex inflammatory disease involving several types of inflammatory cells and multiple inflammatory mediators. Although abnormal numbers of inflammatory cells such as macrophages, dendritic cells, neutrophils, and T lymphocytes have been documented in COPD, the relationship between these cell types and the sequence of their appearance and persistence is largely unknown. Alveolar macrophages have been identified as one of the major cell types that plays a key role in orchestrating the inflammatory events associated with the pathophysiology of COPD. One of the major functions of macrophages is the secretion of chemotactic factors and this function is markedly increased on exposure to cigarette smoke (CS). This enhanced release of chemoattractants results in increased lung neutrophil infiltration, which is thought to be a key event in the development of COPD. The molecular basis for this amplified inflammatory response is not very clear, but it could be due to an alteration in signal transduction pathways within the macrophage. Based on existing literature, an attempt has been made to create a comprehensive review of the signal transduction pathways that link the activation of macrophages with the increased recruitment of neutrophils into the airways. Some of the major stimuli that activate macrophages and cause them to secrete chemotactic factors have been identified as CS, wood smoke, ozone, bacterial endotoxin, and proinflammatory cytokines such as interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. These stimuli seem to activate mainly redox-sensitive transcription factors such as nuclear factor (NF)-kappa B and activator protein (AP)-1, both of which play a major role in the synthesis and secretion of chemotactic factors such as IL-8 and leukotriene B(4) (LTB(4)). The pathways involved in the synthesis and secretion of other factors such as macrophage chemotactic protein-1 (MCP-1) and growth-related oncogene-alpha (Gro-alpha) have also been reviewed.

Associations of IL6 polymorphisms with lung function decline and COPD

BACKGROUND

Interleukin-6 (IL6) is a pleiotropic pro-inflammatory and immunomodulatory cytokine which probably plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). There is a functional single nucleotide polymorphism (SNP), -174G/C, in the promoter region of IL6. It was hypothesised that IL6 SNPs influence susceptibility for impaired lung function and COPD in smokers.

METHODS

Seven and five SNPs in IL6 were genotyped in two nested case-control samples derived from the Lung Health Study (LHS) based on phenotypes of rate of decline of forced expiratory volume in 1 s (FEV(1)) over 5 years and baseline FEV(1) at the beginning of the LHS. Serum IL6 concentrations were measured for all subjects. A partially overlapping panel of nine IL6 SNPs was genotyped in 389 cases of COPD from the National Emphysema Treatment Trial (NETT) and 420 controls from the Normative Aging Study (NAS).

RESULTS

In the LHS, three IL6 SNPs were associated with decline in FEV(1) (0.023< or =p< or =0.041 in additive models). Among them, the IL6_-174C allele was associated with a rapid decline in lung function. The association was more significant in a genotype-based analysis (p = 0.006). In the NETT-NAS study, IL6_-174G/C and four other IL6 SNPs, all of which are in linkage disequilibrium with IL6_-174G/C, were associated with susceptibility to COPD (0.01< or =p< or =0.04 in additive genetic models).

CONCLUSION

The results suggest that the IL6_-174G/C SNP is associated with a rapid decline in FEV(1) and susceptibility to COPD in smokers.

IL1B polymorphisms modulate cystic fibrosis lung disease

RATIONALE

Variability in pulmonary disease severity is found in patients with cystic fibrosis (CF) who have identical mutations in the CF transmembrane conductance regulator (CFTR) gene. We hypothesized that one factor accounting for heterogeneity in pulmonary disease severity is variation in the family of genes affecting the biology of interleukin-1 (IL-1), which impacts acquisition and maintenance of Pseudomonas aeruginosa infection in animal models of chronic infection.

METHODS

We genotyped 58 single nucleotide polymorphisms (SNPs) in the IL-1 gene cluster in 808 CF subjects from the University of North Carolina and Case Western Reserve University (UNC/CWRU) joint cohort. All were homozygous for DeltaF508, and categories of "severe" (cases) or "mild" (control subjects) lung disease were defined by the lowest or highest quartile of forced expired volume (FEV(1)) for age in the CF population. After adjustment for age and gender, genotypic data were tested for association with lung disease severity. Odds ratios (ORs) comparing severe versus mild CF were also calculated for each genotype (with the homozygote major allele as the reference group) for all 58 SNPs. From these analyses, nine SNPs with a moderate effect size, OR < or =0.5 or >1.5, were selected for further testing. To replicate the case-control study results, we genotyped the same nine SNPs in a second population of CF parent-offspring trios (recruited from Children's Hospital Boston), in which the offspring had similar pulmonary phenotypes. For the trio analysis, both family-based and population-based associations were performed.

RESULTS

SNPs rs1143634 and rs1143639 in the IL1B gene demonstrated a consistent association with lung disease severity categories (P < 0.10) and longitudinal analysis of lung disease severity (P < 0.10) in CF in both the case-control and family-based studies. In females, there was a consistent association (false discovery rate adjusted joint P-value <0.06 for both SNPs) in both the analysis of lung disease severity in the UNC/CWRU cohort and the family-based analysis of affection status.

CONCLUSION

Our findings suggest that IL1beta is a clinically relevant modulator of CF lung disease.

Gene polymorphisms of IL-6(-174) G/C and IL-1Ra VNTR in asthmatic children

OBJECTIVE

To check for the association of genetic polymorphisms of IL-6-(-174)G/C and IL-1RaVNTR with the susceptibility and severity of asthma in Egyptian children.

METHODS

Subjects included 69 asthmatic children and 98 healthy unrelated controls from the Nile Delta of Egypt. Cases consisted of 20 males and 49 females with an age mean +/- SD is 7.5 +/- 2.1 ranging between 2-13 years. DNA amplification using PCR with sequence-specific primers was done for detection of promotor single nucleotide polymorphism of IL-6 gene as well as intron 2 VNTR of IL-1Ra gene. Frequency of case-genotypes or alleles were compared to controls using Fisher exact test and Odds ratio.

RESULTS

Cases showed significant higher frequency of the genotypes: IL-6-174 GG (P<0.05, OR=3.2, 95% CI=1.09-10) that was evident mainly in the uncontrolled asthma subgroup indicative of the possibility of being a severity genotype. All cases as well as case-subgroups showed high significant frequency of IL-1Ra A1A1 (p<0.0001, OR=1.5, 95% CI=1.3-1.8). This may be considered a susceptibility genotype. Cases have also shown significant lower frequency of IL-6(-174) GC and IL-1Ra A1A2 genotypes (P<0.001 and P<0.0001 respectively).

CONCLUSION

IL-6 and IL-1Ra polymorphisms can be considered genetic markers for bronchial asthma susceptibility and/or severity among Egyptian children. This may have a potential impact on family counseling and management.

Cytokine genotype and phenotype effects on lung function decline in firefighters

OBJECTIVE

We conducted this study to evaluate the association of cytokine genotypes and sputum concentrations on longitudinal decline in lung function in firefighters.

METHODS

In 67 firefighters with at least four pulmonary function tests, DNA was analyzed for functional polymorphisms of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1RA), IL-8, IL-10, tumor necrosis factor-alpha (TNF-alpha) genes, and sputum evaluated for cytokine concentration by ELISA.

RESULTS

The annual rate of FEV1 decline was greater in firefighters with TT genotypes at IL-10 (-819) (P=0.009) and with CT or TT genotypes at IL-1RA (2018) (P=0.050). These genotypes were not associated with concentrations of sputum cytokine, but increased IL-1RA was associated with a slower rate of FEV1 decline (P=0.025), as was increased sputum macrophage count (P=0.002).

CONCLUSIONS

Cytokine genotypes were associated with the rate of FEV1 decline but did not alter concentrations of sputum cytokine. Increased sputum IL-1RA may be protective.

The different expression patterns of interleukin-1 receptor antagonist in systemic lupus erythematosus

The interleukin-1 receptor antagonist (IL1RN or IL-1Ra) is a natural antagonist of IL-1-beta. Using IL1RN as a possible marker in patients with systemic lupus erythematosus (SLE), we evaluated whether uIL1RN single nucleotide polymorphisms (SNPs) were associated with the pathogenesis of SLE in Taiwanese, and specifically whether IL1RN (rs315952) was significantly associated with end-stage renal disease. We examined IL1RN isoform expression patterns in patients with SLE to determine whether the expressions play a role in the pathogenesis of SLE. Both case-control and family-based association studies were used. For the case-control study, 104 patients with SLE and 97 normal controls were recruited, and for the family-based study, 11 families with SLE without renal disorder were recruited from the 104 patients with SLE. Eight IL1RN SNPs (rs2234678, rs2234679, rs315951, rs315952, rs419598, rs432014, rs447713, and rs451578) were selected for the family-based study. Reverse-transcriptase-polymerase chain reaction (RT-PCR) was used to determine the expression pattern of each isoform. Our results showed that IL1RN (rs315952) was significantly associated with SLE in patients without renal disorder in the family-based study, after disease stratification, but was not significantly associated with SLE in the case-control study. In the family-based study, the haplotype of IL1RN (AGCCTTAG) was significantly associated with SLE (chi2 = 11.714, P < 0.001). Using RT-PCR to determine the expression pattern of the IL1RN isoforms, we found different expression patterns between normal controls and patients with SLE, with an addition of IL1RN isoform4 or the low expression of IL1RN isoform1. We concluded that IL1RN and its isoforms were involved in the pathogenesis of SLE.

Genotype and haplotype determination of IL1B (g. −511C>T and g. +3954C>T) and (IL1RN) in pediatric nephrolithiasis

BACKGROUND

Nephrolithiasis is a multifactorial and polygenic disorder characterized by presence of stones in urinary tract. Interleukin1 (IL1) plays role in process of bone loss/hypercalciuria and is involved in formation of kidney stones. We investigated the association between IL1B promoter region and exon-5 (g.-511C>T and g. +3954C>T) polymorphism and variable number of tandem repeats in IL1 receptor antagonist, IL1RN (IVS2) with risk of stone formation in childhood nephrolithiasis in north Indian population.

METHODS

Control group of 60 healthy pediatric individuals (age range =4-16 y) and 50 pediatric nephrolithiasis patients (age range =2-14 y) were studied. Polymorphism was detected by PCR based restriction analysis. Haplotypes for IL1B and IL1RN were constructed using Arlequin v2.0 software.

RESULTS

Distribution of IL1RN gene polymorphism demonstrated significant difference (p=0.023). Pediatric patients had significantly higher frequency of allele I in IL1RN (16% vs. 1.7%). The distribution of IL1B (g. -511C>T and g. +3954C>T) genotypes in patients and controls were similar (p=0.263 and 0.694 respectively). There was a significant difference in haplotype frequencies between pediatric patients and control group (p<0.05). Haplotype T-E1-I showed>7-folds risk for nephrolithiasis (p=0.033; OR=7.07, 95% CI=1.16-42.84).

CONCLUSIONS

Significant association was observed for allele I(*) of IL1RN however, no association was observed for IL1B. Haplotype T-E1-I was significantly associated with higher risk of pediatric nephrolithiasis. These findings suggest that the IL1RN and haplotyping may be an influential marker for susceptibility to pediatric nephrolithiasis.

Gene therapy for chronic obstructive pulmonary disease: twilight or triumph?

Chronic obstructive pulmonary disease (COPD) is a clinical syndrome presenting as progressive airflow limitation that is poorly reversible as a result of bronchitis and emphysema. The prevalence of COPD is alarming and even more so its current and projected impact on morbidity and mortality. To date, there are no effective treatments for emphysema, nor are there efficient clinical management strategies. Existing and prospective therapies, although promising, have yet to demonstrate their efficacy to slow, halt or reverse the disease. Novel approaches using gene therapy and stem cell technologies may offer new opportunities. However, this will remain almost entirely dependent on a more thorough understanding of the pathogenesis of COPD. This review is not aimed at highlighting the vast effort of studying COPD, but rather describing the state of the field in an abstract fashion to expose the focus of research efforts to date, which has primarily been limited to predisposing factors and inflammation. We would like to draw attention to other elements of the disease, such as the alveolar remodelling that characterises emphysema. Although the main cause may prove to be elusive, carefully designed clinical treatment and management may deliver the required therapeutic outcome.

Genetic association of interleukin-1β and receptor antagonist (IL-1Ra) gene polymorphism with allograft function in renal transplant patients

Cytokines are known to be important mediators during renal graft outcome. The present study was therefore, conducted to determine the impact of IL-1beta and its receptor antagonist polymorphism on allograft outcome. We evaluated single nucleotide polymorphism (SNPs) in interleukin-1 gene cluster, IL-1beta (promoter region -511 and exon-5 +3954) and IL-1Ra (86-bp VNTR) in 136 renal transplant recipients and 150 normal healthy controls by polymerase chain restriction based (PCR-RFLP) analysis. Recipients were HLA matched and clinically characterized including delayed graft function (DGF), rejection episode (RE) and stable graft function (SGF). Haplotypes and linkage disequilibrium (LD) were determined using SNPAnalyzer software. Significant difference was observed for the frequency distribution of the three sites of IL-1 gene among patients and controls (p<0.001, 0.022 and <0.001 respectively). When RE and DGF were compared to SGF, only IL-1Ra showed significant differences among RE and SGF (p=0.014) and DGF and SGF (p=0.020). The presence of 1/2 genotype showed 18 folds risk in RE and 10 folds in DGF (OR=18.000 and OR=10.667 respectively). The majority of recipients with SGF had 1-4 HLA mismatch whereas RE had 5-8 mismatches. Risk for rejection increased >6 folds (OR=6.571; p<0.01) for 5-8 mismatches. Haplotypes constructed with the combination of three polymorphisms in IL-1 gene cluster showed significant difference between RE and SGF group. LD value for IL-1beta (promoter region) and IL-1Ra and IL-1beta promoter and exon-5 gene in the control group indicated strong association among the variants (D'=0.37, p<0.0001 and D'=0.29, p=0.002). Our study demonstrate that genetically determined low production of IL-1Ra may be a risk factor for RE and DGF and that IL-1beta/IL-1Ra haplotype influences the impact of allograft outcome. These findings may significantly abet in better perception of the survival of the graft.

Laboratory markers for COPD in “susceptible” smokers

Smoking is the major risk factor for the development of chronic obstructive pulmonary disease. Apart from the important preventive steps of smoking cessation, there are no other specific treatments for COPD that are as effective in reversing the condition. However, only a relatively small proportion of smokers-about 15%-will develop clinically relevant COPD. Allergy, airway hyper-responsiveness (AHR) to methacholine, and gender differences have been proposed to identify individuals susceptible to the development of COPD. However, variable response to cigarette smoke clearly suggests genetic susceptibility. Among the COPD candidate genes are those (a) that effect the production of proteases and antiproteases, (b) modulate the metabolism of toxic substances in cigarette smoke, (c) are involved with mucocilliary clearance, and (d) that influence inflammatory mediators. Recently, sputum cells from smokers with and without COPD were tested for Microsatellite DNA Instability (MSI) with positive results. This finding suggests that MSI can be a useful marker of genetic susceptibility and thereby indicate destabilization of the genome in the "susceptible" smoker. Nevertheless, COPD lacks established viable biomarkers to predict and monitor disease progression and outcome variables. Such monitoring tools may be induced sputum, exhaled air condensate, peripheral blood, urine, bronchial biopsies, and bronchoalveolar lavage fluid (BALF). This review summarizes recent research on potential laboratory markers in smokers and subsequent COPD development.

Association between interleukin-1 receptor antagonist gene and asthma-related traits in a German adult population

BACKGROUND

A recent study in German and Italian families associated variants in the interleukin-1 receptor antagonist (IL1RA) gene with asthma. The aim of the present study was to further investigate the role of single nucleotide polymorphisms (SNPs) in the IL1RA gene in the development of atopy and lifelong asthma in a population-based study.

METHODS

DNA samples from the German centres of the European Community Respiratory Health Survey were analysed for genetic variants in the IL1RA gene and the development of asthma, atopy and bronchial hyperreactivity.

RESULTS

Carriers of the rare G allele of SNP rs447713 had a significantly increased risk of developing asthma (P = 0.0013) and allergic sensitization (P = 0.0119). Carriers of the rare C allele of SNP rs3087271 had an increased risk of asthma (P = 0.0227) and high immunoglobulin E (IgE) levels (P = 0.0232). A haplotype built from eight SNPs in the IL1RA gene (A-C-A-G-A-C-G-A) was associated with a higher prevalence of asthma (P = 0.007) and high total IgE (P = 0.02). Bronchial hyperreactivity was positively associated with the haplotype A-C-G-G-A-C-G-C (P = 0.02) and negatively with the A-C-G-G-A-C-T-C (P = 0.03).

CONCLUSION

A previously described association between IL1RA and asthma in families could be reproduced in a population-based sample. The genetic variants of IL1RA gene do not to seem to affect asthma alone, but to act as modulators of asthma-related traits as well, where different haplotypes drive the development of different phenotypes.

Understanding genomics: implications for the emergency medicine physician and the treatment of asthma

TARGET AUDIENCE

Physicians, nurse practitioners, and physician assistants who evaluate and care for children with minor illnesses. Specialists including pediatricians, emergency physicians, pediatric emergency physicians, family practitioners, and pediatric nurse practitioners will find this information particularly useful.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to: 1. Explain the role of single-nucleotide polymorphisms and haplotypes in the development of asthma and asthma exacerbations. 2. Describe what is currently known about how environmental influences interact with genotype to produce an asthmatic phenotype. 3. Describe the 3 possible effects of a single-nucleotide polymorphism or haplotype on pharmacology in the context of asthma.

Familial lung cancer: genetic susceptibility and relationship to chronic obstructive pulmonary disease

Lung cancer continues to be the leading cause of cancer death, and although most lung cancer is attributable to cigarette smoking, underlying genetic susceptibility is suggested by studies demonstrating familial aggregation. The first family linkage study of lung cancer has identified linkage of lung, laryngeal, and pharyngeal cancer in families to a region on chromosome 6q23-25. Because lung cancer and chronic obstructive pulmonary disease (COPD) are known to aggregate in families beyond shared risk associated with smoking, the linkage results are compared and contrasted with results from genomewide linkage and association studies and candidate gene studies searching for genes for lung cancer, lung function, and COPD. Linkage on chromosome 6q to both lung cancer and lung function, and on 12 to lung cancer, COPD, and lung function, together with overlap in candidate genes for these outcomes, suggests that future research into underlying genetic mechanisms of lung disease would benefit from broadening the collection of family history data and better defining the "high risk" population. As familial risk of lung disease is better defined, referral into screening programs and prevention trials can be better targeted to reach families with both a history of lung cancer and COPD.

Pulmonary cachexia, systemic inflammatory profile, and the interleukin 1beta -511 single nucleotide polymorphism

BACKGROUND

Cachexia is common in chronic obstructive pulmonary disease (COPD) and is thought to be linked to an enhanced systemic inflammatory response.

OBJECTIVE

We investigated differences in the systemic inflammatory profile and polymorphisms in related inflammatory genes in COPD patients.

DESIGN

A cross-sectional study was performed in 99 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease stages II-IV), who were stratified by cachexia based on fat-free mass index (FFMI; in kg/m2: <16 for men and <15 for women) and compared with healthy control subjects (HCs). Body composition was determined by bioelectrical impedance analysis. Plasma concentrations and gene polymorphisms of interleukin 1beta (IL-1beta -511), IL-6 (IL-6 -174), and the tumor necrosis factor system (TNF-alpha -308 and lymphotoxin-alpha +252) were determined. Plasma C-reactive protein, leptin, and urinary pseudouridine (as a marker of cellular protein breakdown) were measured.

RESULTS

Fat mass, leptin, and pseudouridine were significantly different (P < 0.001) between noncachectic patients (NCPs) and cachectic patients (CPs: n = 35); the systemic inflammatory cytokine profile was not. NCPs had a body compositional shift toward a lower fat-free mass and a higher fat mass compared with HCs. CPs and NCPs had a greater systemic inflammatory response (P < 0.05) than did HCs, as reflected in C-reactive protein, soluble TNF-R75, and IL-6 concentrations. The overall distribution of the IL-1beta -511 polymorphism was significantly different between the groups (P < 0.05).

CONCLUSIONS

In COPD patients, who are characterized by an elevated systemic inflammatory response, cachexia is not discriminatory for the extent of increase in inflammatory status. This study, however, indicates a potential influence of genetic predisposition on the cachexia process.

A candidate gene approach of immune mediators effecting the susceptibility to and severity of upper gastrointestinal tract diseases in relation to Helicobacter pylori and Epstein-Barr virus infections

This review focuses on immunogenetic aspects of diseases of the upper gastrointestinal tract in which infectious agents may play a role in the aetiopathogenesis, such as Helicobacter pylori, Epstein-Barr virus (EBV) and HIV. Gastric adenocarcinoma is a common cancer all around the world, with declining incidences in Europe and high incidences in Asia and central and south America. Together with gastric atrophy and peptic ulcer disease, gastric adenocarcinoma belongs to the commonest upper gastrointestinal tract diseases. These diseases are multifactorial and factors such as smoking and dietary habits contribute to the pathogenesis. More recently, scientists have turned their eyes on the host. Functional polymorphisms in the genes regulating the host immune system may contribute to the susceptibility to and progression of disease. In multifactorial and polygenetic diseases, candidate gene studies of single nucleotide polymorphisms (SNPs) detect small to moderate relative risks. Unfortunately, only a few functional SNPs have been identified. The candidate gene approach can be seen as a useful first step in exploring causal pathways between genetic determinants and complex diseases such as those mentioned above. To date, little is known about the immunogenetics of upper gastrointestinal tract diseases. We review the literature on H. pylori, EBV and gene polymorphisms that affect key immune mediators influencing the pathogenesis of the inflammatory response, such as the genes that code for the IL-1 family, TNF-alpha, lymphotoxin alpha, and IL-10. IL-1, IL-10, lymphotoxin alpha and TNF-alpha polymorphisms increase the risk of upper gastrointestinal pathogenesis in H. pylori-infected patients, whereas IL-1 and TNF-alpha polymorphisms confer risk in EBV-infected patients.

Interleukin 1 receptor antagonist gene polymorphism and risk of lung cancer: a possible interaction with polymorphisms in the interleukin 1 beta gene

Tobacco smoking is the main risk factor for lung cancer. Only 10-15% of smokers develop lung cancer, suggesting that genetic factors are of importance in determining individual susceptibility to the disease. Several studies in recent years indicate that chronic inflammation is a cofactor in lung carcinogenesis. We have previously reported an association of interleukin 1 beta gene (IL1B) polymorphisms with lung cancer risk. Interleukin-1 receptor antagonist (IL-1Ra) has been implicated in carcinogenesis of different cancer types. IL-1Ra binds competitively to the same membrane receptor as interleukin-1beta (IL-1beta) and thereby acts as an antagonist to the pro-inflammatory actions of IL-1beta. The aim of the study was to examine whether a common VNTR polymorphism in the interleukin 1 receptor antagonist gene (IL1RN) is associated with lung cancer risk. Due to the tight relationship between IL1RN and IL1B, we also explored the possibility of an interaction between the two genes. The study population comprised of 340 non-small cell lung cancer cases and 412 healthy controls of Norwegian origin. Our results indicate that individuals homozygous for the IL1RN*1 allele and carrying the IL1B-31T allele had increased risk of non-small cell lung cancer (odds ratio C/T 3.08; 1.10-8.62 and T/T 5.87; 2.15-16.05). Furthermore, IL1RN*1 carriers had nearly two-fold higher levels of bulky/hydrophobic DNA adducts in the lung. Our findings support the significance of IL1 gene cluster polymorphisms and risk of lung cancer.

Polymorphisms of TNFα, IL1β, and IL1RN genes in chronic obstructive pulmonary disease

It is recognized that genetic factors play a role in the susceptibility to COPD. COPD is characterized by airflow limitation. Chronic inflammation causes small airway disease and parenchymal destruction, leading to the airflow limitation. Polymorphisms in pro-inflammatory cytokine genes may confer a risk for the development of COPD. A case-control association study was performed in Japanese population (88 COPD patients and 61 controls) and Egyptian population (106 patients and 72 controls). Genotype and allele frequencies of the TNFalpha -308 G/A and +489 G/A polymorphisms, the IL1beta -511 C/T, -31 T/C, and +3954 C/T polymorphisms, and a VNTR polymorphism in intron 2 of the IL1RN gene were investigated. In addition, pairwise haplotype frequencies were analyzed. When studied independently, none of the polymorphisms were associated with the development of COPD in both populations. However, in the Egyptian population, the distributions of the haplotype (IL1beta -31 T/C : IL1beta +3954 C/T) were significantly different between the COPD patients and the controls (p(corr)=0.0037). Our findings suggest that this haplotype within the IL1beta gene may be involved in the pathogenesis of COPD and that the genetic factors of COPD susceptibility might be different between different populations.

The role of environmental tobacco smoke in genetic susceptibility to asthma

PURPOSE OF REVIEW

The increase in asthma prevalence over the past 50 years suggests that exposures to environmental risk factors have also increased during this time. Environmental tobacco smoke is one of the most common indoor air pollutants and has been associated in epidemiologic studies with airway and allergic phenotypes in exposed individuals. However, symptoms occur in only some individuals, suggesting that individual genotypes determine sensitivity to environmental tobacco smoke exposure. In this review, we summarize studies evaluating the relationship between genotype, environmental tobacco smoke exposure and risk for asthma and related phenotypes.

RECENT FINDINGS

Using either candidate gene or genome-wide approaches, a number of studies have examined interactions between genotypes at specific loci or genome regions and environmental tobacco smoke exposure and risk for asthma or asthma-associated phenotypes. These studies implicate variation in the genes encoding the alpha(2)-adrenergic receptor, interleukin-10, glutathione S-transferase M1, interleukin-1 beta and interleukin-1 receptor antagonist, matrix metalloproteinases 1 and 12, interleukin-4 receptor alpha-chain, alpha(1)-antitrypsin, and microsomal epoxide hydrolase, as well as unknown genes on chromosomes 1p, 5q and 17p as contributing toward susceptibility in smoking exposed individuals.

SUMMARY

Considering environmental tobacco smoke exposure in genetic studies may help to identify more homogeneous subsets of patients that share a common disease etiology. By stratifying samples by environmental tobacco smoke exposure, associations or linkages with specific polymorphisms or chromosomal region may be revealed, as illustrated in the studies discussed in this review.

Interleukin-1beta causes pulmonary inflammation, emphysema, and airway remodeling in the adult murine lung

The production of the inflammatory cytokine interleukin (IL)-1 is increased in lungs of patients with chronic obstructive pulmonary disease (COPD) or asthma. To characterize the in vivo actions of IL-1 in the lung, transgenic mice were generated in which human IL-1beta was expressed in the lung epithelium with a doxycycline-inducible system controlled by the rat Clara cell secretory protein (CCSP) promoter. Induction of IL-1beta expression in the lungs of adult mice caused pulmonary inflammation characterized by neutrophil and macrophage infiltrates. IL-1beta caused distal airspace enlargement, consistent with emphysema. IL-1beta caused disruption of elastin fibers in alveolar septa and fibrosis in airway walls and in the pleura. IL-1beta increased the thickness of conducting airways, enhanced mucin production, and caused lymphocytic aggregates in the airways. Decreased immunostaining for the winged helix transcription factor FOXA2 was associated with goblet cell hyperplasia in IL-1beta-expressing mice. The production of the neutrophil attractant CXC chemokines KC (CXCL1) and MIP-2 (CXCL2), and of matrix metalloproteases MMP-9 and MMP-12, was increased by IL-1beta. Chronic production of IL-1beta in respiratory epithelial cells of adult mice causes lung inflammation, enlargement of distal airspaces, mucus metaplasia, and airway fibrosis in the adult mouse.