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Background: We previously reported that the ILVBL gene on chromosome 19p13.1 was associated with the risk for aspirin-exacerbated respiratory disease (AERD) and the percent decline of forced expired volume in one second (FEV1) after an oral aspirin challenge test. In this study, we confirmed the association between polymorphisms and haplotypes of the ILVBL gene and the risk for AERD and its phenotype.Methods: We recruited 141 AERD and 995 aspirin-tolerant asthmatic (ATA) subjects. All study subjects underwent an oral aspirin challenge (OAC). Nine single nucleotide polymorphisms (SNPs) with minor allele frequencies above 0.05, which were present in the region from 2 kb upstream to 0.5 kb downstream of ILVBL in Asian populations, were selected and genotyped.Results: In an allelic association analysis, seven of nine SNPs were significantly associated with the risk for AERD after correction for multiple comparisons. In a codominant model, the five SNPs making up block2 (rs2240299, rs7507755, rs1468198, rs2074261, and rs13301) showed significant associations with the risk for AERD (corrected P = 0.001-0.004, OR = 0.59-0.64). Rs1468198 was also significantly associated with the percent decline in FEV1 in OAC tests after correction for multiple comparisons in the codominant model (corrected P = 0.033), but the other four SNPs in hapblock2 were not.Conclusion: To the best of our knowledge, this is the first report of an association between SNPs on ILVBL and AERD. SNPs on ILVBL could be promising genetic markers of this condition. [ABSTRACT FROM AUTHOR]

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea and worsening lung function due to remodeling of the lung, including epithelial mesenchymal transition. ADAM33 is a disintegrin and metalloprotease domain-containing protein, which may be related to lung fibrosis by exerting angiogenesis and remodeling of the lung. Thus, we evaluated the association of single-nucleotide polymorphisms (SNPs) of ADAM33 with the risk of IPF. Methods: A total of 237 patients with IPF and 183 healthy subjects participated in the present study. Nine polymorphisms were selected. Genotyping was performed by single-base extension. Polymorphisms and haplotypes were analyzed for associations with the risk of IPF using multiple logistic regression models controlling for age, gender, and smoking status as covariates. Results: All SNPs were in Hardy-Weinberg equilibrium. The minor allele frequency (MAF) of rs628977G>A in intron 21 was significantly lower in subjects with surgical IPF than in normal controls in the recessive model [33.2 vs. 38.0 %, p = 0.02, OR = 0.40 (0.19-0.84)]. When the subjects with clinical IPF were included, the difference in MAF persisted with a p value of 0.03 [OR = 0.50 (0.27-0.94)]. Conclusions: ADAM33 rs628977G>A was marginally associated with a decreased risk of IPF in a recessive model. [ABSTRACT FROM AUTHOR]

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea and worsening lung function. ACE is increased in the bronchoalveolar lavage fluid from patients with IPF, suggesting the role of ACE in the pathogenesis of IPF. We evaluated the role of single-nucleotide polymorphisms (SNPs) in the development risk of IPF. Methods: Two-hundred twenty patients with IPF and 456 healthy subjects were included in this study. Eleven polymorphisms were selected among those reported previously. Genotype was performed by single base extension. Results: Although absolute LD (|D′| = 1 and r= 1) was not present, 11 SNPs showed tight LDs. The logistic analysis of the all of 11 SNPs on the ACE genes between patients with IPF and healthy subjects were found to be related with the risk of IPF in recessive type. However, in patients with IPF diagnosed by surgical lung biopsy, only two SNP of −5538T>C and +21288_insdel SNPs were related with the risk of IPF in co-dominant type, and there were no SNPs related with the risk of IPF in dominant type. In patients with IPF diagnosed by clinical criteria or surgical lung biopsy, four SNPs on promoter (−5538T>C, −5508A>C, −3927T>C, −115T>C), one on intron (+15276A>G), one on exon (+21181G>A), and one in three prime region (+21288_insdel) were related with the risk of IPF. Conclusions: This study showed a newly discovered SNP of ACE associated with the risk of development of IPF. ACE −5538T>C and −5508A>C significantly associated with risk of IPF in Korea. [ABSTRACT FROM AUTHOR]

Aspirin-exacerbated respiratory disease (AERD) is a nonallergic clinical syndrome characterized by a severe decline in forced expiratory volume in one second (FEV1) following the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin. The effects of genetic variants have not fully explained all of the observed individual differences to an aspirin challenge despite previous attempts to identify AERD-related genes. In the present study, we performed genome-wide association study (GWAS) and targeted association study in Korean asthmatics to identify new genetic factors associated with AERD. A total of 685 asthmatic patients without AERD and 117 subjects with AERD were used for the GWAS of the first stage, and 996 asthmatics without AERD and 142 subjects with AERD were used for a follow-up study. A total of 702 SNPs were genotyped using the GoldenGate assay with the VeraCode microbead. GWAS revealed the top-ranked variants in 3′ regions of the HLA-DPB1 gene. To investigate the detailed genetic effects of an associated region with the risk of AERD, a follow-up targeted association study with the 702 single nucleotide polymorphisms (SNPs) of 14 genes was performed on 802 Korean subjects. In a case-control analysis, HLA-DPB1 rs1042151 (Met105Val) shows the most significant association with the susceptibility of AERD ( p = 5.11 × 10; OR = 2.40). Moreover, rs1042151 also shows a gene dose for the percent decline of FEV1 after an aspirin challenge ( p = 2.82 × 10). Our findings show that the HLA-DPB1 gene polymorphism may be the most susceptible genetic factor for the risk of AERD in Korean asthmatics and confirm the importance of HLA-DPB1 in the genetic etiology of AERD. [ABSTRACT FROM AUTHOR]

Airway remodeling and exacerbated airway narrowing in asthma have been attributed to the regulation of intracellular Ca2+ by sarcoplasmic reticulum (SR) of the airway smooth muscle cells. The protein encoded by obscurin, cytoskeletal calmodulin and titin-interacting RhoGEF ( OBSCN) is a crucial factor in determining the SR architecture in Obscn−/− mice. This study genotyped a total of 55 common single-nucleotide polymorphisms (SNPs) in 592 Korean asthmatics including 163 aspirin exacerbated respiratory disease (AERD) cases and 429 aspirin-tolerant asthma (ATA) controls. Eight SNPs, including two nonsynonymous polymorphisms rs1188722C>T (Leu2116Phe) and rs1188729G>C (Cys4642Ser), and one haplotype BL2_ht1 showed statistically significant associations with AERD development ( p=0.003-0.03). Two variants, rs1188722C>T (Leu2116Phe) and rs369252C>A, also revealed nominal association with FEV1 decline by aspirin provocation in asthmatics ( p=0.03-0.04). Intriguingly, rs1188722C>T (Leu2116Phe) is a highly conserved amino acid residue among species, suggesting its functional relevance to AERD. In addition, the A allele of rs369252C>A, which was more prevalent in AERD than in ATA, was predicted as a potential branch point (BP) site for alternative splicing (BP score=4.29). Although further functional evaluation is required, our findings suggest that OBSCN polymorphisms, in particular, highly conserved nonsynonymous Leu2116Phe variant, might contribute to aspirin hypersensitivity in asthmatics. [ABSTRACT FROM AUTHOR]

BACKGROUND:The functional role of the human diffuse panbronchiolitis critical region 1 (DPCR1) gene, located in the major histocompatibility complex class I, has not been widely investigated. However, this gene is a well known genetic marker for diffuse panbronchiolitis, a disease affecting human respiratory bronchioles. In this study we explored the association between polymorphisms in DPCR1 and aspirin-exacerbated respiratory disease (AERD), an asthma phenotype. METHODS: Genotyping of 6 polymorphisms was carried out in a total of 189 Korean asthmatic patients stratified into 93 AERD cases and 96 aspirin tolerant asthma controls. Subjects who exhibited significant decrease of FEV1 by aspirin provocation were identified as AERD subjects. Logistic and regression analyses were performed to investigate the association between DPCR1 polymorphisms and the risk of AERD as well as FEV1 decline. RESULTS: Initial analysis revealed significant association of rs2517449 with AERD, with a P value of .03 via a recessive model; however, the association signal disappeared after multiple testing corrections. In addition, rs2517449 and rs2240804 also showed association signals with decline of FEV1 after aspirin provocation (P = .007 and .03, respectively, in a recessive model). After testing for multiple comparisons, only the association signal from rs2517449 was retained (Pcorr = .04), while other polymorphisms showed no associations with the risk of AERD and FEV1 decline. CONCLUSIONS: Our results show that polymorphisms in DPCR1 are not associated with the risk of AERD. [ABSTRACT FROM AUTHOR]

Aspirin-exacerbated respiratory diseases (AERD) are associated with the metabolism of arachidonic acid. FPR2 (formyl peptide receptor2) is a high-affinity ligand receptor for potent anti-inflammatory lipid metabolites: lipoxins. Thus, functional alterations of the FPR2 may contribute to AERD. We investigated the relationship between single-nucleotide polymorphisms (SNPs) in the FPR2 and AERD. Asthmatics were categorized into AERD <15% decreases in forced expiratory volume in one second (FEV1), and/or naso-ocular reactions after oral aspirin challenge (n=170) and aspirin-tolerant asthma (ATA, n=268). In all, 11 SNPs were genotyped. FPR2 protein expressions on CD14-positive monocytes in peripheral blood were measured using flow cytometric analysis. We performed RT-PCR of the FPR2 mRNA expressed by peripheral blood mononuclear cells. Logistic regression analysis showed that the minor allele frequency of FPR2 −4209T>G (rs1769490) in intron 2 was significantly lower in the AERD group (n=170) than in the ATA group (n=268) (P=0.006, Pcorr=0.04, recessive model). The decline of FEV1 after aspirin challenge was significantly lower in the subjects with GG homozygotes of FPR2 −4209T>G than those with the other genotypes (P=0.0002). Asthmatic homozygotes for FPR2 −4209T>G minor allele exhibited significantly higher FPR2 protein expression in CD14-positive monocytes than did those with the common allele of FPR2 −4209T>G allele (P=0.01). There was no difference in the expression of the wild form and the exon 2 deleted variant form of FPR2 gene according to the genotypes of FPR2 −4209T>G. The minor allele at FPR2 −4209T>G may have a protective role against the development of AERD, via increase of FPR2 protein expression in inflammatory cells. [ABSTRACT FROM AUTHOR]

Background: Nasal polyps, part of the aspirin triad symptoms, are edematous protrusions arising from the mucosa of the nasal sinuses. Although the causative factors and pathogenesis of the polyps are unknown, the significant effect of human leukocyte antigen-DR (HLA-DR) expression in nasal polyps and genetic associations of the major histocompatibility complex class II, DR alpha (HLA-DRA) with immune-mediated diseases have been revealed. Methods: To investigate the associations of HLA-DRA polymorphisms with nasal polyposis in asthmatic patients and in aspirin-hypersensitive subgroups, 22 single nucleotide polymorphisms (SNPs) were genotyped in a total of 467 asthmatic patients including 158 nasal polyp-positive and 309 polyp-negative subjects. Results: Statistical analysis showed that four SNPs (p = 0.0005-0.02; Pcorr = 0.009-0.033) and one haplotype (p = 0.002; Pcorr = 0.029) were significantly associated with the presence of nasal polyposis in asthmatic patients. In further analysis, although significant signals disappeared after corrections for multiple testing, two HLA-DRA polymorphisms (rs9268644C>A, rs3129878A>C) were found to be potential markers for nasal polyp development in aspirin-tolerant asthma (p = 0.005 and 0.007, respectively) compared with the aspirin-exacerbated respiratory disease (p > 0.05) subgroup. In silico analysis predicted major 'C' allele of rs14004C>A in 5′-untranslated region as a potential binding site for regulatory glucocorticoid receptor. In addition, sequence nearby rs1051336G>A is suspected to be a pyrimidine-rich element that affects mRNA stability. Conclusion: Despite the need for replication in larger cohorts and/or functional evaluations, our findings suggest that HLA-DRA polymorphisms might contribute to nasal polyposis susceptibility in patients with asthma. [ABSTRACT FROM AUTHOR]

The human ubiquitin protein ligase E3C (UBE3C) regulates airway inflammatory responses and is hypothesized to be associated with the presence of nasal polyps in asthma-related diseases. A total of 24 UBE3C single-nucleotide polymorphisms (SNPs) were genotyped in a 467 Korean asthma cohort that was stratified into more homogenous phenotypes of 114 aspirin-exacerbated respiratory disease subgroup and 353 aspirin-tolerant asthma (ATA) subjects. Association analysis revealed that 16 UBE3C SNPs were significantly associated with presence of nasal polyps in the overall asthma group (P=0.0008 and Pcorr=0.01; odds ratio (OR)=0.60). The strength of association from 10 polymorphisms was increased in the ATA subgroup (P=0.0002 and Pcorr=0.003; OR=0.49). In addition, UBE3C_ht1 was found to be consistently associated with nasal polyps in the overall asthmatics group (P=0.006) and the ATA phenotype (P=0.002; Pcorr=0.02) via a codominant mechanism. Our findings provide evidence that variations in UBE3C are potent genetic markers of nasal polyps development in Korean asthmatics and may contribute novel insights into the clinical relevance and potential involvement of UBE3C in respiratory deficiencies. [ABSTRACT FROM AUTHOR]

Aspirin exacerbated respiratory disease (AERD) induces bronchoconstriction in asthmatic patients characterized with a clinical condition of severe decline in forced expiratory volume in one second (FEV1) after ingestion of aspirin. Two genes consisting a heterodimer, transporter 1 and 2, ATP-binding cassette, sub-family B (MDR/TAP) (TAP1 and TAP2) within the major histocompatibility complex (MHC) region, have been implicated in immunodeficiency and bronchiectasis development. To investigate the associations of TAP1 and TAP2 genetic polymorphisms with AERD and phenotypic FEV1 decline, a total of 43 common single-nucleotide polymorphisms (SNPs) including 12 SNPs of TAP1 and 31 SNPs of TAP2 were genotyped in 93 AERD patients and 96 aspirin-tolerant asthma controls. Interestingly, regression analysis revealed that polymorphisms and haplotypes of TAP2 were associated with FEV1 decline by aspirin provocation (P=0.002-0.04), with about twofold decline rate of FEV1 in most of minor homozygotes compared with major homozygotes. In addition, nominal evidences of association between TAP2 and AERD development were observed (P=0.02-0.04). However, TAP1 polymorphisms showed no relations to both AERD and FEV1 decline after aspirin challenge (P>0.05). Although further functional evaluations and replications are required, our preliminary findings provide supporting information that variants of TAP2 might be predisposing factors for FEV1 decline-related symptoms. [ABSTRACT FROM AUTHOR]

Asthma manifests as TH2-dominant airway inflammation regulated by inducible T-cell kinase ( ITK). To investigate associations between genetic variants of the ITK gene and asthma, 31 single-nucleotide polymorphisms (SNPs) were genotyped in 303 normal controls and 498 asthmatics and the two groups were compared using logistic regression models. The functional effects of the ITK promoter SNP were assessed using pGL3 luciferase reporter systems and gel-shift assays. The minor allele− 196C>T in the promoter region of the ITK gene was significantly more frequent in asthmatics than in controls. The luciferase activity of the PGL3- ITK-196T allele construct was higher than that of the − 196C allele. In the gel-shift assay, − 196T double-stranded oligonucleotides bound more strongly to Jurkat cell nuclear protein compared to the − 196C double-stranded oligonucleotides. People with the −rare allele 196C>T may be more susceptible to asthma via transcriptional regulation of the ITK gene. [ABSTRACT FROM AUTHOR]

Abstract: Background: In this study, the association of asthma with CD53, a member of the tetraspanin family, was assessed for the first time in a mechanism-based study. Methods: Genetic polymorphisms of CD53 were analyzed in 591 subjects and confirmed in a replication study of 1001 subjects. CD53 mRNA and protein levels were measured in peripheral blood leukocytes, and the effects of the promoter polymorphisms on nuclear factor binding were examined by electrophoretic mobility shift assay. Cellular functional studies were conducted by siRNA transfections. Results: Among tagging SNPs of CD53, the −1560 C>T in the promoter region was significantly associated with asthma risk. Compared with the CC genotype, the CT and TT genotypes were associated with a higher asthma risk, with odd ratios of 1.74 (P =0.009) and 2.03 (P =0.004), respectively. These findings were confirmed in the replication study with odd ratios of 1.355 (P =0.047) and 1.495 (P =0.039), respectively. The −1560 C>T promoter SNP had functional effects on nuclear protein binding as well as mRNA and protein expression levels in peripheral blood leukocytes. When CD53 was knocked down by siRNA in THP-1 human monocytic cells stimulated with house dust mite, the production of inflammatory cytokines as well as NFκB activity was significantly over-activated, suggesting that CD53 suppresses over-activation of inflammatory responses. Conclusions: The −1560 C>T SNP is a functional promoter polymorphism that is significantly associated with population asthma risk, and is thought to act by directly modulating nuclear protein binding, thereby altering the expression of CD53, a suppressor of inflammatory cytokine production. [Copyright &y& Elsevier]

Abstract: The angiotensinogen (AGT) gene enhances the effect of several bronchoconstrictors and produces a peptide that is accumulated in the airways of asthma patients; events that may underpin the pathogenesis of aspirin-intolerant asthma (AIA). To carry out a case-control analysis between AGT and aspirin-induced bronchospasm following treatment with an anti-asthma drug, montelukast (MLK), 38 single nucleotide polymorphisms (SNPs) in AGT were genotyped in 56 AIA cohort. Genotyping was performed with TaqMan assay and haplotypes were inferred using PHASE algorithm ver. 2.0. Statistical analyses of each SNPs and haplotypes were performed using SAS version 9.1. Among 13 variants displaying significant signals, two SNPs (+2401C>G and +2476C>T) in the intronic region of AGT were significantly associated with modification of drug response even after correction for multiple testing (P =0.0009–0.002; P corr =0.02–0.03). Furthermore, the two variants also exhibited associations with MLK response rate (P =0.0003–0.0006; P corr =0.006–0.01). Although our results are preliminary and further replication in a larger-scale group of subjects should be warranted, these observations provide evidence that AGT variants might be one of genetic factors involved in the response of anti-asthma drugs in AIA patients. [Copyright &y& Elsevier]

Abstract: Nuclear factor–κB (NF-κB) orchestrates the expression of genes responsible for airway inflammation and remodeling in asthma. The activity of NF-κB is tightly regulated by IKBA, which may be modulated by genetic polymorphisms of the IKBA gene. We investigated the association between asthma susceptibility and IKBA gene polymorphisms in a Korean population. Genotyping was performed in BA (bronchial asthma) and NC (normal control). We measured reverse transcription–polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and luciferase reporter assays, respectively. A −673A>T (rs2233407) was associated with asthma development in subjects with atopic asthma (odds ratio = 0.56, p = 0.004). The IKBA mRNA level was higher in B-cell lines with the rs2233407 TT genotype compared with those with the AA genotype (p = 0.024). The luciferase activity of the rs2233407 T genotype was higher than that of the A (p = 0.002). The cytoplasmic levels of total IKBA and IKBA [p-S32] were higher in B cell lines of the rs2233407 TT genotype than those of the AA (p = 0.016 and p = 0.036, respectively), whereas nuclear NF-κB activity in cells with the IKBA rs2233407 AA genotype was higher than in cells with the AA (p = 0.038). The IKBA rs2233407 A>T polymorphism may predispose individuals to the development of atopic asthma via regulation of IKBA gene expression at the transcriptional level. [ABSTRACT FROM AUTHOR]