Polymorphisms in interleukin-1B and its receptor antagonist genes and the risk of chronic obstructive pulmonary disease in a Korean population: a case–control study

Association of Variants in IL-1RN (rs2234663) and IL-1β (rs1143627, rs16944) and Interleukin-1β Levels with Colorectal Cancer: Experimental Study and In Silico Analysis

BACKGROUND/OBJECTIVES

Colorectal cancer (CRC) is a multifactorial disease where the inflammatory state is crucial. This study analyzes the association of the IL-1RN (rs2234663) and IL-1β (rs1143627, rs16944) variants and IL-1β levels with CRC.

METHODS

This study included 230 CRC patients and 256 controls. Genotypes were determined by PCR and plasma IL-1β levels by ELISA. RegulomeDB analyzed the variants' functional impacts, while OncoDB assessed IL-1β and IL-1RN expression's influence on CRC.

RESULTS

The A1A1 genotype and dominant pattern of the rs2234663 variant were risk factors for CRC, whereas the A1A2 genotype showed a protective effect. The TC genotype of the rs1143627 variant and the T allele of rs16944 were associated with increased risk, whereas the C allele had a protective effect. The A1A1 genotype was associated with stage I-II CRC diagnosis, while the A2A2 genotype was associated with stage III-IV and ethanol consumption. The CC genotype of rs1143627 was associated with people younger than 50 years and tobacco use, and the TCCC genotype was related to stage III-IV stages and metastasis and hemorrhoids (p < 0.05). IL-1β levels were not associated with CRC. In silico analysis revealed that the variants are in located in important regions regulatory of genes. Elevated IL-1B and IL-1RN mRNA levels were found in CRC, linked to clinicopathological features of the disease.

CONCLUSIONS

The analyzed variants are associated with CRC and may influence gene regulation by being located at critical sites of key genetic regulators.

Association between single-nucleotide polymorphism of cytokines genes and chronic obstructive pulmonary disease: A systematic review and meta-analysis

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease with high morbidity and mortality rates worldwide. Cytokines, which are the main regulators of immune responses, play crucial roles in inflammatory diseases such as COPD. Moreover, certain genetic variations can alter cytokine expression, and changes in cytokine level or function can affect disease susceptibility. Therefore, investigating the association between genetic variations and disease progression can be useful for prevention and treatment. Several studies have explored the association between common genetic variations in cytokine genes and COPD susceptibility. In this study, we summarized the reported studies and, where possible, conducted a systematic review and meta-analysis to evaluate the genetic association between various cytokines and COPD pathogenesis. We extracted relevant articles from PubMed and Google Scholar databases using a standard systematic search strategy. We included a total of 183 studies from 78 separate articles that evaluated 50 polymorphisms in 12 cytokine genes in this study. Our analysis showed that among all reported cytokine polymorphisms (including TNF-α, TGF-β, IL1, IL1RN, IL4, IL4R, IL6, IL10, IL12, IL13, IL17, IL18, IL27, and IL33), only four variants, including TNF-α-rs1800629, TGF-β1-rs6957, IL13-rs1800925, and IL6-rs1800796, were associated with the risk of COPD development. This updated meta-analysis strongly supports the association of TNF-α-rs1800629, TGF-β1-rs6957, IL13-rs1800925, and IL6-rs1800796 variants with a high risk of COPD.

SMAD4 rs10502913 is Significantly Associated with Chronic Obstructive Pulmonary Disease in a Chinese Han Population: A Case-Control Study

Background

COPD is a respiratory disease caused by a combination of genetic and environmental factors. Polymorphism, as a genetic factor, can affect the susceptibility of the disease of COPD. In this study, we assessed the relationship between the polymorphisms of three genes and COPD risk in a Chinese Han population.

Patients and Methods

A total of 376 patients diagnosed with COPD and 284 control subjects were enrolled in this study. Multivariate logistic regression analysis was used to analyze the association between three polymorphisms (SMAD4 rs10502913, IL-4 rs2070874, HSPA1L rs2227956) and COPD susceptibility.

Results

The SMAD4 rs10502913 GG and AG genotype significantly increased COPD risk (adjusted OR = 2.235, 95% CI 1.198–4.104; adjusted OR = 2.218, 95% CI 1.204–4.151, respectively) compared with the AA genotype. In the stratification analyses, the GG genotype significantly increased the risk of COPD in subjects aged 60 and over (adjusted OR = 2.519, 95% CI 1.266–5.015) and with a smoking history of less than 30 years (p=0.009; adjusted OR = 3.751; 95% CI 1.398–10.062). This increased risk was more pronounced in the group of GOLD I and GOLD II (adjusted OR = 3.628, 95% CI 1.022–12.885; adjusted OR = 2.394, 95% CI 1.004–5.710, respectively). In addition, AG genotype was associated with an increased COPD risk in subjects aged 60 and over (adjusted OR = 2.599, 95% CI 1.304–5.176) and in smokers (p=0.021; adjusted OR = 2.269; 95% CI 1.132–4.548). This increased risk was more obvious in the group of GOLD III COPD (p=0.047; adjusted OR = 2.532; 95% CI 1.012–6.336).

Conclusion

Our present study indicated that the genotype GG and AG of SMAD4 rs10502913 are associated with an increased risk of COPD in a Chinese Han population. Further validation studies with large-scale populations are needed to confirm our findings.

The Interleukin-1 (IL-1) Superfamily Cytokines and Their Single Nucleotide Polymorphisms (SNPs)

Interleukins (ILs)—which are important members of cytokines—consist of a vast group of molecules, including a wide range of immune mediators that contribute to the immunological responses of many cells and tissues. ILs are immune-glycoproteins, which directly contribute to the growth, activation, adhesion, differentiation, migration, proliferation, and maturation of immune cells; and subsequently, they are involved in the pro and anti-inflammatory responses of the body, by their interaction with a wide range of receptors. Due to the importance of immune system in different organisms, the genes belonging to immune elements, such as ILs, have been studied vigorously. The results of recent investigations showed that the genes pertaining to the immune system undergo progressive evolution with a constant rate. The occurrence of any mutation or polymorphism in IL genes may result in substantial changes in their biology and function and may be associated with a wide range of diseases and disorders. Among these abnormalities, single nucleotide polymorphisms (SNPs) can represent as important disruptive factors. The present review aims at concisely summarizing the current knowledge available on the occurrence, properties, role, and biological consequences of SNPs within the IL-1 family members.

New Insights into the Role of NLRP3 Inflammasome in Pathogenesis and Treatment of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by chronic airway obstruction and emphysema. Accumulating studies have shown that the onset and development of COPD are related to an aberrant immune response induced by the dysregulation of a number of genetic and environmental factors, while the exact pathogenesis of this disease is not well defined. Emerging studies based on tests on samples from COPD patients, animal models, pharmacological and genetic data suggest that the NLR family pyrin domain containing 3 (NLRP3) inflammasome activation is required in the lung inflammatory responses in the development of COPD. Although the available clinical studies targeting the inflammasome effector cytokine, IL-1β, or IL-1 signaling do not show positive outcomes for COPD treatment, many alternative strategies have been proposed by recent emerging studies. Here, we highlight the recent progress in our understanding of the role of the NLRP3 inflammasome in COPD and propose possible future studies that may further elucidate the roles of the inflammasome in the pathogenesis or the intervention of this inflammatory lung disease.

Association between chronic obstructive pulmonary disease and interleukins gene variants: A systematic review and meta-analysis

Interleukins are cytokines involved in systemic inflammation and immune system regulation. Many studies have investigated the association between common genetic variations in interleukin-coding genes and COPD susceptibility. In this study, a systematic review and meta-analysis was performed to evaluate the association between interleukin gene variations and COPD pathogenesis. Association studies were retrieved from PubMed and Google Scholar databases using the standard systematic search strategy. A total of 26 different studies evaluating eight polymorphisms in four interleukin genes were included in this study. In overall comparisons, IL1β-rs16944, -rs1143627, -rs1143634, IL13-rs20541 polymorphisms were found not to be associated with the increased risk for developing COPD. However, IL1RN-rs2234663 and IL13-rs1800925 showed a strong association with COPD. We showed that the CC genotype carriers of the IL6-rs1800795 are at significantly higher risk of developing COPD (OR = 1.31, 95% CI: 1.04-1.64, P = 0.01) compared to GG carriers. In case of IL6-rs1800796, individuals with CC and CG genotypes showed a lower risk to develop COPD (OR = 0.46, 95%CI: 0.32-0.66, P > 0.00). This updated meta-analysis strongly supports the association of IL1RN-rs2234663, IL6-rs1800795, -rs1800795 and IL13-rs1800925 variants with COPD.

IL-1β and IL-1Ra Variant Profiles in Turkish Patients with Diabetic Peripheral Neuropathy

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common complications of Type 2 diabetes mellitus (T2DM). This study was conducted to investigate the possible association between interleukin-1β (IL-1β) rs16944 /IL-1 receptor antagonist (IL-1Ra) VNTR variants and genetic susceptibility to DPN in a Turkish cohort.

METHODS

A total of 200 subjects were enrolled in this study, 98 patients with DPN and 102 cases of age and sex-matched healthy controls. Genotyping was performed for all individuals using PCR-RFLP analysis.

RESULTS

IL-1β rs16944 CC genotype had a 3.20-fold increased risk for DPN (p=0.0003, OR=3.20, 95% Cl:1.72-5.96). IL-1β rs16944 CT genotype was higher in healthy control than patients (p=0.004). IL-1β rs16944 C allele was higher in the patient group compared to controls while T allele was lower in patients than controls (p=0.003). IL-1Ra VNTR a1/a1 and a2/a2 genotypes were lower in DPN patients while a1/a2 genotype was higher in patients (p=0.045). The patients carrying a1/T haplotype had decreased risk of DPN than control groups (p=0.004). The patients carrying a2/a2 genotype had lower HDL level (p=0.039). The subjects carrying a2/a2 genotype had higher total cholesterol level while the subjects carrying a1/a2 genotype had lower total cholesterol (p=0.026 and p=0.037, respectively). IL-1Ra a1 allele was associated with higher HDL level (p=0.041).

CONCLUSION

Findings of this study indicated that the IL-1β rs16944 and IL-1Ra VNTR variants are probably to be associated with susceptibility DPN risk in a Turkish cohort.

Association between Genetic Variations of MERTK and Chronic Obstructive Pulmonary Disease in Koreans

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease. To date, a large number of clinical studies have been conducted to investigate the association between genetic variations and COPD. However, little is known regarding the genetic susceptibility of Koreans to this disease. MER receptor tyrosine kinase (MERTK) plays important roles in the inhibition of inflammation and in the clearance of apoptotic cells. Here, we investigated the association between genetic variations in MERTK and the development of COPD in Koreans.

METHODS

We conducted genetic analysis of MERTK using genomic DNA samples from 87 patients with COPD and 88 healthy controls and compared the frequency of each variation or haplotype between the patient and control groups. Subsequently, the effect of each variation was evaluated using in vitro assays.

RESULTS

Ten variations were identified in this study, four of them for the first time. In addition, we found that the frequency of each variation or haplotype was comparable between the patient and control groups. However, we observed that the frequency for the wild-type haplotype was higher in the control group, compared to that in the group of patients with COPD, in the subgroup analysis of current smokers, although the difference was not statistically significant (P = 0.080). In in vitro assays, we observed that none of the variations affected the activity of the promoter or the expression of MERTK.

CONCLUSION

Our findings indicate that the susceptibility to COPD is not related to the genetic variations or haplotypes of MERTK in Koreans.

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.

Interleukin-1B-31T/C promoter polymorphism and chronic obstructive pulmonary disease risk: a meta-analysis

INTRODUCTION

The role of interleukin (IL)-1β -31T/C promoter polymorphism in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been studied with inconsistent results. This meta-analysis was performed to assess the association of IL-1β -31T/C promoter polymorphism with COPD susceptibility.

MATERIAL AND METHODS

Published case-control studies from PubMed and China National Knowledge Infrastructure (CNKI) databases were retrieved. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

Six case-control studies were included in this meta-analysis. The pooled effect size showed that IL-1β -31T/C was significantly associated with COPD susceptibility in an overdominant genetic model (CC+TT vs. TC, OR: 0.77, 95% CI: 0.63-0.94), indicating that homozygotes (CC and TT) had a decreased risk for COPD compared with heterozygotes (TC). In the subgroup analysis by ethnicity, the results indicated that IL-1β -31T/C was significantly correlated with COPD susceptibility in Asians (overdominant model, OR: 0.75, 95% CI: 0.61-0.93), further suggesting a protective role of IL-1β -31T/C in COPD pathogenesis in Asians. Moreover, after excluding the study without Hardy-Weinberg equilibrium, the pooled results were robust and no publication bias was found in this study.

CONCLUSIONS

This meta-analysis suggests that IL-1β -31T/C promoter polymorphism confers protection against COPD in Asians.

Polymorphisms in inflammasome genes and risk of coal workers' pneumoconiosis in a Chinese population

Background

Coal workers' pneumoconiosis (CWP), resulting from the inhalation of silica-containing coal mine dust, is characterized by fibrosing nodular lesions that eventually develop into progressive pulmonary fibrosis. Recently, it has been hypothesized that inflammasomes could have a crucial role in the host response to silica and recent studies show that the inflammasome contributes to inflammation and pulmonary fibrosis. NLRP3, CARD8 are components of the NLRP3 inflammasome, which triggers caspase 1-mediated IL-1β and IL-18 release. In the present study, we investigated whether common single nucleotide polymorphisms (SNPs) in inflammasome genes are associated with CWP.

Methods

We performed an association study analyzing 3 NLRP3, 1 CARD8, 1 IL-1β, 2 IL-18 SNPs in a case-control study of 697 CWP and 694 controls. Genotyping was carried out by the TaqMan method.

Results

The NLRP3 rs1539019 TT genotype was associated with a significantly increased risk of CWP (adjusted odds ratio (OR) = 1.39, 95% confidence interval (CI) = 1.07–1.81), compared with the GG/GT genotype, in particular among smokers (adjusted OR = 1.67, 95%CI = 1.15–2.42). In addition, the polymorphism was significantly associated with risk of CWP patients with stage I.

Conclusions

This is the first report showing an association between the NLRP3 rs1539019 polymorphism and CWP, and suggests that this polymorphism may confer increased risk for the development of the disease. Further studies are warranted to confirm our findings.

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.

Inflammation, chronic obstructive pulmonary disease and aging

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli, particularly cigarette smoke. The determinants of the dysregulated immune responses, which play a role both in the onset and continuation of COPD, are largely unknown. We examined several molecular mechanisms regulating the inflammatory pathway, such as cytokine polymorphisms, miRNA expression, and DNA methylation in COPD and aging, with the aim to provide evidence supporting the view that aging of the immune system may predispose to COPD.

RECENT FINDINGS

The incidence of COPD increases with age. The pathogenesis of the disease is linked to a chronic inflammation and involves the recruitment and regulation of innate and adaptive immune cells. A chronic systemic inflammation characterizes aging and has been correlated with many diseases, most of them age-related.

SUMMARY

COPD and aging are associated with significant dysregulation of the immune system that leads to a chronic inflammatory response. The similar molecular mechanisms and the common genetic signature shared by COPD and aging suggest that immunosenescence may contribute to the development of COPD.

Role of interleukin-1 and MyD88-dependent signaling in rhinovirus infection

Rhinoviral infection is an important trigger of acute inflammatory exacerbations in patients with underlying airway disease. We have previously established that interleukin-1β (IL-1β) is central in the communication between epithelial cells and monocytes during the initiation of inflammation. In this study we explored the roles of IL-1β and its signaling pathways in the responses of airway cells to rhinovirus-1B (RV-1B) and further determined how responses to RV-1B were modified in a model of bacterial coinfection. Our results revealed that IL-1β dramatically potentiated RV-1B-induced proinflammatory responses, and while monocytes did not directly amplify responses to RV-1B alone, they played an important role in the responses observed with our coinfection model. MyD88 is the essential signaling adapter for IL-1β and most Toll-like receptors. To examine the role of MyD88 in more detail, we created stable MyD88 knockdown epithelial cells using short hairpin RNA (shRNA) targeted to MyD88. We determined that IL-1β/MyD88 plays a role in regulating RV-1B replication and the inflammatory response to viral infection of airway cells. These results identify central roles for IL-1β and its signaling pathways in the production of CXCL8, a potent neutrophil chemoattractant, in viral infection. Thus, IL-1β is a viable target for controlling the neutrophilia that is often found in inflammatory airway disease and is exacerbated by viral infection of the airways.

Meta-analyses on suspected chronic obstructive pulmonary disease genes: a summary of 20 years' research

RATIONALE

Chronic obstructive pulmonary disease (COPD) is a complex disorder with high mortality worldwide. Studies on the role of candidate genes and their polymorphisms in COPD development have so far produced ambiguous results.

OBJECTIVES

The aim of this study was to reveal the role of COPD candidate genes using data collected in previous research.

METHODS

We performed meta-analyses on 20 polymorphisms in 12 genes, after searching the PubMed and Embase databases for publications on COPD. These genes involve three main pathways associated with COPD development: the inflammatory, protease-antiprotease balance, and antioxidant pathways.

MEASUREMENTS AND MAIN RESULTS

We obtained significant results for three TGFB1 polymorphisms, although these were based only on a few studies. The IL1RN VNTR polymorphism increases the risk for COPD (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.09-2.65), whereas the TNFA -308 G/A polymorphism does so only in Asian populations (OR, 2.01; 95% CI, 1.21-3.31). The GSTP1 I105V polymorphism was protective for COPD in Asian populations only (OR, 0.69; 95% CI, 0.56-0.85).

CONCLUSIONS

These results demonstrate the importance of ethnicity in identifying specific COPD genes.

A specific interleukin-1B haplotype correlates with high levels of IL1B mRNA in the lung and increased risk of non-small cell lung cancer

Epidemiological evidence suggests a relationship between chronic inflammation and lung cancer. Inflammation in the lung may be modulated by host genetic factors such as polymorphisms in inflammatory genes. Identification of polymorphisms in inflammatory genes may help understanding interindividual differences in susceptibility to lung cancer. We have investigated single-nucleotide polymorphisms (SNPs) and their haplotypes in the regulatory region of the IL1B gene in association to non-small cell lung cancer (NSCLC) risk. Our previous work showed that two promoter SNPs C-511T and T-31C modulated NSCLC risk. In the present study, we show that G-3893A and G-1464C located in the enhancer region of the IL1B gene may also affect this risk, with odds for developing NSCLC being 0.69 [95% confidence interval (CI), 0.52-0.92] for -3893 A-allele and 0.63 (95% CI, 0.47 - 0.83) for -1464 C-allele. The associations were particularly prominent in patients with TP53 mutations in the tumor. Inference of the haplotype structures showed that -3893 G, -1464 G, -511 C and -31 T formed a specific haplotype (GGCT) with near complete linkage disequilibrium in lung cancer patients but not in controls. Furthermore, the risk haplotype (GGCT) was present in 65% of cases compared with 36% of controls. Quantitative analysis of RNA in normal lung tissue of the patients showed that the risk haplotype was correlated with significantly higher IL1B messenger RNA (mRNA) levels compared with the non-risk haplotype (ACTC). These data suggest that a specific IL1B haplotype associated with increased IL1B gene expression increases the risk of NSCLC.