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Purpose: Melanocortin 3 Receptor ( MC3R) is one of the families of seven-transmembrane G-protein-coupled receptors, and a recent study showed that MCR3 promoter polymorphism was significantly associated with the susceptibility of tuberculosis (TB) in South African population. Methods: We analyzed six MC3R polymorphisms to examine the genetic effects on the risk of pulmonary TB in Korean subjects by using TaqMan assays and case-control analyses. Results: Using statistical analyses, one common promoter polymorphism ( MC3R rs11575886 T > C) was found to be associated with an increased risk of pulmonary TB. The frequency of the C-bearing genotype of rs11575886 was higher in pulmonary TB patients than in normal controls ( p = 0.03, OR = 1.46) although the significance was not retained after correction. In silico analysis for the difference of transcription binding factor (TF), motif between C and T allele demonstrated that the TF motif and its threshold scores of C allele were lower than those of T allele. Conclusions: The C allele of rs11575886 could be a risk allele for the pulmonary TB by affecting the binding of TF. Our findings suggest that polymorphisms in MC3R might be one of genetic factors for the risk of pulmonary TB development in Korean subjects. [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]

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]

Background. Exacerbation of asthma symptoms due to aspirin ingestion may lead to life-threatening lung failure. The adhesion molecule CD58 gene may play a crucial role in aspirin-exacerbated respiratory disease (AERD) pathogenesis by mediating the biological functions of asthma-inducing mechanisms including T helper cells, proinflammatory cytokines, and natural killer T cells. Objective. This study aimed to investigate the association of CD58 variations with aspirin-induced bronchospasm in Korean asthma patients. Methods. Seven single-nucleotide polymorphisms were selected for genotyping based on previously reported polymorphisms in the International HapMap database. Genotyping was carried out using TaqMan assay and 2 major haplotypes were obtained in 163 AERD cases and 429 aspirin-tolerant asthma controls. Frequency distributions of CD58 variations were analyzed using logistic and regression models. Results. Results showed that none of the analyzed CD58 single-nucleotide polymorphisms and haplotypes was significantly associated with AERD development and fall rate of FEV1 by aspirin provocation, an important diagnostic marker of aspirin hypersensitivity. Conclusions. This preliminary study suggests that CD58 does not affect AERD susceptibility in a Korean population, and may provide a new direction for future disease etiology. [ABSTRACT FROM AUTHOR]

Background: Aspirin-intolerant asthma (AIA) is a clinical syndrome characterized by acute bronchoconstriction following the ingestion of aspirin. Solute carrier family 22, member 2 (SLC22A2), also known as organic cation transporter 2 (OCT2), is predominantly expressed in the luminal membrane of airway epithelial cells and has been shown to mediate the transport of prostaglandins on the cyclooxygenase pathway which is regulated by aspirin blockage. Recently, SLC22A2-mediated uptake inhibition by several nonsteroidal anti-inflammatory drugs and decreased SLC22A2 transport activity by its genetic variants have been elucidated in asthma. Methods: To investigate the associations between AIA and genetic polymorphisms of the SLC22A2 gene, 18 variants were genotyped in 163 AIA subjects and 429 aspirin-tolerant asthma (ATA) controls. Logistic analyses were used to evaluate p values for the associations of SLC22A2 polymorphisms with AIA. Results: One common polymorphism in intron 5, i.e. rs316021, was significantly associated with susceptibility to AIA (p = 0.004, Pcorr= 0.05, OR = 0.60, 95% CI = 0.43-0.85 in a codominant model). The minor allele frequency of rs316021 in the AIA group was significantly lower than that in the ATA controls. In addition, a polymorphism in intron 4 (rs3912161) and a haplotype (SLC22A2-ht3) showed significantly stronger association signals with the FEV1 fall rate induced by aspirin provocation in AIA subjects compared with ATA controls (p = 0.004, Pcorr = 0.05). Conclusion: Our findings suggest that SLC22A2 could be a susceptibility gene for aspirin intolerance in asthmatics. Copyright © 2011 S. Karger AG, Basel [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]

Introduction: The kinesin family number 3A ( KIF3A) gene on the human chromosomal 5q31-33 region, which is known as a susceptibility locus for immune diseases including asthma, plays a crucial role in generation of cilia. Results: A treatment with aspirin in the human bronchial epithelial cells increased the mRNA expression level of KIF3A compared to that of the untreated control ( P ≤ 0.01), and nasal polyp epithelia from aspirin-intolerant asthma (AIA) patients also showed a higher expression of KIF3A protein than aspirin-tolerant asthma controls. Further logistic analyses revealed that most polymorphisms of KIF3A were significantly associated with AIA ( P = 0.0004-0.02; P = 0.004-0.04) and the decline of forced expiratory volume at 1 s (FEV)% by aspirin provocation ( P = 0.004-0.04; P = 0.03). Discussion: Our findings suggest that the KIF3A gene and/or its polymorphisms might have a susceptibility effect on AIA, providing a new step toward controlling aspirin intolerance in asthmatics. [ABSTRACT FROM AUTHOR]

Background: Eosinophilic infiltration and peripheral blood eosinophilia in asthma require the cooperation of eosinophil-specific cytokines and chemokines and their receptors. Objective: We investigated the association of polymorphisms in CCR3 and IL5RA with asthma susceptibility or peripheral blood eosinophilia and the effects of the polymorphisms on receptor expression. Methods: Polymorphisms in CCR3 and IL5RA were identified and genotyped in 576 asthmatic patients and 180 healthy control subjects. CCR3 and IL-5 receptor α (IL-5Rα) protein expression on eosinophils was measured by means of flow cytometry. Results: Although polymorphisms in CCR3 were not associated with asthma susceptibility, the CCR3 haplotype ht2 showed a negative gene dose effect on the eosinophil count (P = .003–.009). IL5RA c.−5091G>A was weakly associated with eosinophil count. The effects of ht2 were greater when paired with IL5RA c.−5091A (P = .001–.002). CCR3 protein expression was higher on eosinophils of asthmatic patients without ht2 than in those with ht2. Asthmatic patients with the IL5RA c.−5091A allele showed higher IL-5Rα expression than those who were homozygous for the G allele. Conclusion: The genetic association between CCR3 polymorphisms and the number of circulating eosinophils was revealed as a novel finding. These associations were more pronounced when the CCR3 polymorphisms were paired with polymorphisms in IL5RA. The protein expression levels of CCR3 and IL-5Rα on peripheral blood eosinophils are associated with the polymorphisms on their own genes. Clinical implications: The identification of single nucleotide polymorphisms and haplotypes of CCR3 and IL5RA might be useful in developing markers for intermediate phenotypes of eosinophil number and in designing strategies to control diseases related to hypereosinophilia. [Copyright &y& Elsevier]

Airway inflammation is a major factor in the pathogenesis of asthma. Interleukin 8 (IL8) is a potent proinflammatory cytokine that interacts with its receptors, IL8RA and IL8RB. We investigated the genetic polymorphisms in IL8, IL8RA, and IL8RB for any association with risk of asthma and peripheral blood eosinophil counts in a Korean population. By carrying out direct sequencing in 24 individuals, we identified 20 sequence variants within exons and their flanking regions, including the 1.5 kb promoter regions of IL8, IL8RA, and IL8RB. Among them, seven common single-nucleotide polymorphisms (SNPs) were selected for genotyping in our asthma cohort ( n = 1,439). Two common haplotypes in IL8 and three in IL8RA and IL8RB (defined as one block) were identified. Although none of the polymorphisms showed a significant association with risk of asthma, IL8RA-B ht2 showed a significant association with the peripheral blood eosinophil counts (%) among asthma patients, e.g., lower eosinophil levels among individuals with the homozygous IL8RA-B ht2 (3.55 ± 3.39%) than among other asthmatic patients (5.52 ± 5.55%; P corr = 0.018). Our findings suggest that polymorphisms and haplotypes in IL8RA and IL8RB might be among the genetic factors underlying production of peripheral blood eosinophil. [ABSTRACT FROM AUTHOR]

Abstract: There has been increasing evidence that genetic mechanisms contribute to the development of aspirin-intolerant asthma (AIA), a life-threatening disease. The complement component (C6) is a constituent of a biochemical cascade that has been implicated in airway epithelial damage and nasal polyposis, and therefore, may be a risk factor for AIA. To investigate the association between C6 variations and AIA in a Korean asthma cohort, 27 SNPs were selected for genotyping based on previously reported polymorphisms in the HapMap database. Genotyping was carried out using TaqMan assay, and five major haplotypes were obtained in 163 AIA cases and 429 aspirin-tolerant asthma (ATA) controls subjects. Genotype frequency distributions of C6 polymorphisms and haplotypes were analyzed using logistic and regression models. Subsequent analyses revealed a lack of association between C6 genetic variations and AIA. From the initial analyses, marginal associations of rs10512766 (p = 0.04 in co-dominant model) and rs4957374 (p = 0.05 in dominant model) with AIA did not reach the threshold of significance after multiple testing corrections; thus this study failed to find convincing evidence that variations in C6 gene influence the risk of AIA in a Korean population. However, these preliminary results may contribute to the etiology of aspirin hypersensitivity in Korean asthmatic 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]

Abstract: The chemokine (C-X-C motif) receptor 3 (CXCR3) gene, on chromosome Xq13, is known to have critical roles in inflammatory and immune responses. In an effort to discover polymorphisms have been implicated in asthma, we investigated the genetic polymorphisms in CXCR3 to evaluate it as a potential candidate gene for a host genetic study of asthma. Statistical analysis revealed that one SNP in intron 1, c.12+234G>A, showed significant association with the risk of asthma development (P =0.007, OR=0.81). By subgroup analyses stratified by gender and atopic status, the genetic effect of c.12+234G>A on asthma was more apparent among male atopic subjects (P =0.0009, OR=0.61). Our findings suggest that polymorphisms in CXCR3 might be one of the genetic factors for the risk of asthma development, especially in male atopic subjects. CXCR3 variation/haplotype information identified in this study will provide valuable information and insight into strategies for the control of asthma and its subgroup, atopy. [Copyright &y& Elsevier]