Se-Min Park

Genome‐wide methylation profile of nasal polyps: relation to aspirin hypersensitivity in asthmatics

To cite this article: Cheong HS, Park S‐M, Kim M‐O, Park J‐S, Lee JY, Byun JY, Park BL, Shin HD, Park C‐S. Genome‐wide methylation profile of nasal polyps: relation to aspirin hypersensitivity in asthmatics. Allergy 2011; 66: 637–644.

Effect of single nucleotide polymorphisms within the interleukin-4 promoter on aspirin intolerance in asthmatics and interleukin-4 promoter activity.

Objective Aspirin affects interleukin-4 (IL-4) synthesis; however, the genetic role of IL-4 has not been evaluated in asthmatics with aspirin hypersensitivity. The objective of the study was to examine the influence of single nucleotide polymorphisms (SNPs) in IL-4 gene on aspirin hypersensitivity in asthmatics at the genetic and molecular levels. Methods Aspirin-intolerant (AIA, n=103) and aspirin-tolerant asthmatics (n=270) were genotyped and functional promoter assays were performed. Results Of 15 SNPs tested, seven (−589T>C (rs2243250) in promoter, −33T>C (rs2070874) in the 5′-untranslated region, +4047A>G (rs2243266), +4144C>G (rs2243267), +4221C>A (rs2243268), +4367G>A (rs2243270), and +5090A>G (rs2243274) in introns) were significantly associated with AIA risk. The frequency of the rare allele (C) of −589T>C was higher in the AIA group than in the aspirin-tolerant asthmatic group (Pcorr=0.016), and a gene dose-dependent decline in forced expiratory volume in 1 s was noted after an aspirin challenge (P=0.0009). Aspirin unregulated IL-4 mRNA production in Jurkat T and K562 leukemia cells. A reporter plasmid assay revealed that aspirin augmented IL-4 promoter transactivation with the −589T>C C and −33T>C C alleles, compared with that bearing the −589T>C T and −33T>C T alleles. Further, electrophoretic mobility shift assay showed the formation of nuclear complexes with −33T>C and −589T>C allele-containing probes; this was augmented by aspirin. The complexes formed with the −33T>C and −589T>C probes were shifted by treatment with anti-CCAAT-enhancer-binding proteins &bgr; and anti-nuclear factor of activated T-cells antibodies, respectively, indicating the inclusion of these transcription factors. Conclusion Aspirin may regulate IL4 expression in an allele-specific manner by altering the availability of transcription factors to the key regulatory elements in the IL4 promoter, leading to aspirin hypersensitivity.

Association analysis of thromboxane A synthase 1 gene polymorphisms with aspirin intolerance in asthmatic patients

AIM Thromboxane A synthase (TBXAS1) converts prostaglandin H to thromboxane A, a potent constrictor of smooth respiratory muscle. Thus, functional alterations of the TBXAS1 gene may contribute to aspirin-intolerant asthma (AIA). MATERIALS & METHODS We investigated the relationship between SNPs in the TBXAS1 gene and AIA. Asthmatics (n = 470) were categorized into AIA (20% or greater decreases in forced expiratory volume in 1 s [FEV(1)], or 15% to 19% decreases in FEV(1) with naso-ocular or cutaneous reactions) and aspirin-tolerant asthma (ATA). A total of 101 SNPs were genotyped. mRNA expression of the TBXAS1 gene by peripheral blood mononuclear cells and plasma thromboxane B2 (TXB2) concentrations were measured by reverse transcriptase (RT)-PCR and ELISA. RESULTS Logistic regression analysis showed that the rare allele frequency of rs6962291 in intron 9 was significantly lower in the AIA group (n = 115) than in the ATA group (n = 270) (p(corr) = 0.04). The linear regression analysis revealed a strong association of rs6962291 with the aspirin challenge-induced FEV(1) fall (p = 0.003). RT-PCR revealed an exon-12-deleted splice variant. We measured TBXAS1 mRNA levels in peripheral blood mononuclear cells. The mRNA levels of the full-length wild-type and splice variant were significantly higher in the TT homozygotes than in the AA homozygotes of rs6962291 (1.00 ± 0.18 vs 0.57 ± 0.03 and 1.00 ± 0.18 vs 0.21 ± 0.05, p = 0.047 and 0.001, respectively). The plasma TXB2 level was significantly lower in rs6962291 AA carriers than in rs6962291 TT (p = 0.016) carriers. CONCLUSION The rare allele of rs6962291 may play a protective role against aspirin hypersensitivity via a lower catalytic activity of the TBXAS1 gene, attributed to the increase of a nonfunctioning isoform of TBXAS1.

Association of peroxisome proliferator-activated receptor-gamma gene polymorphisms with the development of asthma.

BACKGROUND The peroxisome proliferator-activated receptors (PPAR) are the nuclear hormone receptor superfamily of ligand-activated transcriptional factors. PPAR-gamma (PPARG) activation downregulates production of Th2 type cytokines and eosinophil function. Additionally, treatment with a synthetic PPARG ligand can reduce lung inflammation and IFN-gamma, IL-4, and IL-2 production in experimental allergic asthma. In patients with asthma, PPARG gene expression is known to be associated with the airway inflammatory and remodeling responses. Thus, genetic variants of PPARG may be associated with the development of asthma. METHODS We genotyped two single nucleotide polymorphisms on the PPARG gene, +34C>G (Pro12Ala) and +82466C>T (His449His), in Korean subjects (839 subjects with asthma and 449 normal controls). RESULTS Association analysis using logistic regression analysis showed that +82466C>T and haplotypes 1(CC) and 2(CT) were associated with the development of asthma (p=0.01-0.04). The frequency of PPARG-ht2 was significantly lower in the patients with asthma compared to the normal controls in codominant and dominant models (p=0.01, p(corr)=0.03 and p=0.02, p(corr)=0.03, respectively). Conversely, the frequency of PPARG-ht1 was significantly higher in the patients with asthma compared to the normal controls in the codominant model [p=0.04, OR: 1.27 (1.01-1.6)]. In addition, the rare allele frequency of +82466C>T was significantly lower in patients with asthma in comparison to normal controls in the codominant model (OR: 0.78, p=0.04). Thus, polymorphism of the PPARG gene may be linked to an increased risk of asthma development.

Association analysis of N-acetyl transferase-2 polymorphisms with aspirin intolerance among asthmatics

AIMS Cysteinyl leukotrienes are inactivated by acetyl coenzyme A-dependent N-acetyltransferase (NAT). Thus, functional alterations of the NAT gene may contribute to the risk of aspirin-intolerant asthma. MATERIALS & METHODS Asthmatics (n = 438) were categorized into aspirin-intolerant asthma (15% or greater decrease in the forced expiratory volume in 1 s or cutaneous reactions, n = 170) or aspirin-tolerant asthma (n = 268) groups. In total, 14 polymorphisms of the NAT2 gene were genotyped by a single-base extension method. RESULTS The distributions of all loci of the 14 SNPs were in Hardy-Weinberg equilibrium (p > 0.05). Among the 14 SNPs, six common SNPs (minor allele frequency >5%) in a Korean population were used for haplotype construction and further statistical analysis. The logistic regression analysis demonstrated that NAT2 -9246G>C and haplotype 2 (TCACGG) were significantly associated with the risk of aspirin-intolerant asthma. The rare allele frequencies of the SNP and Ht2 were significantly higher in the aspirin-intolerant asthma group than in the aspirin-tolerant asthma group (p(corr) = 0.03 and p(corr) = 0.02 in codominant model). CONCLUSION In a large genetic epidemiology study of aspirin-intolerant asthma in a Korean population, genetic polymorphisms of NAT2 were found to be related to a risk of aspirin hypersensitivity among asthmatics.

Asthma-predictive genetic markers in gene expression profiling of peripheral blood mononuclear cells.

Purpose We sought to identify asthma-related genes and to examine the potential of these genes to predict asthma, based on expression levels. Methods The subjects were 42 asthmatics and 10 normal healthy controls. PBMC RNA was subjected to microarray analysis using a 35K array; t-tests were used to identify genes that were expressed differentially between the two groups. A multiple logistic regression analysis was applied to the differentially expressed genes, and area under the curve (AUC) values from receiver operating characteristic (ROC) curves were obtained. Results In total, 170 genes were selected using the following criteria: P≤0.001 and ≥2-fold change. Among these genes, 57 were up-regulated and 113 were down-regulated in asthmatics versus normal controls. A multiple logistic regression analysis was done using more stringent criteria (P≤0.001 and ≥5-fold change), and eight genes were selected as candidate asthma biomarkers. Using these genes, 255 models (28-1) were generated. Among them, only 85 showed P≤0.05 by multiple logistic regression analysis. Based on the AUCs from ROC curves for the 85 models, we found that the best model consisted of the genes MEPE, MLSTD1, and TRIM37. The model showed 0.9928 of the AUC with 98% sensitivity and 80% specificity. Conclusions MEPE, MLSTD1, and TRIM37 may be useful biomarkers for asthma.

Association analysis of RGS7BP gene polymorphisms with aspirin intolerance in asthmatic patients

BACKGROUND Signal-regulated palmitoylation of RGS7BP(regulator of G-protein-signaling 7-binding protein) initiates the activation of G-protein-coupled receptors (GPCRs), including muscarinic receptors, which contribute to the development of asthma and its subphenotypes. OBJECTIVE To determine the association of RGS7BP gene polymorphisms with the development of aspirin-exacerbated respiratory disease (AERD). METHODS We evaluated the association of RGS7BP gene polymorphisms with response to oral aspirin challenge and with responsiveness to methacholine challenge. RGS7BP messenger RNA splice variants in peripheral blood platelets from patients with different single-nucleotide polymorphisms were analyzed by reverse-transcription polymerase chain reaction. RESULTS Logistic regression analysis of RGS7BP gene polymorphisms in patients with AERD (n = 102) and aspirin-tolerant asthma (n = 429) revealed that a haplotype of block 3 consisting of rare alleles +98092 C>G, +98853 C>T, and +104450 T>G of the RGS7BP gene was associated with AERD. Multiple linear regression analysis showed that asthmatic patients carrying ht2/ht2 in block 3 were more responsive to aspirin challenge than those not carrying ht2 (P = .008 in a codominant model). The log-transformed provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20% for methacholine was significantly dependent on the BL3-ht2 haplotype. No significant differences in platelet expression of different RGS7BP messenger RNA splice variants were detected between those with and without the BL3-ht2 haplotype. CONCLUSION BL3-ht2 of RGS7BP may be an important genetic variant associated with AERD. The haplotype of block 3 may play a protective role against aspirin hypersensitivity in asthma, perhaps by altering the responsiveness of muscarinic receptors.

Effect and mechanism of lipopolysaccharide on allergen-induced interleukin-5 and eotaxins production by whole blood cultures of atopic asthmatics

Interleukin (IL)‐5 and eotaxin families regulate the development of eosinophilic inflammation of asthma in a co‐operative manner. The exposure to airborne lipopolysaccharide (LPS) induces varying degrees of airflow obstruction and neutrophilic airway inflammation. Production of IL‐5 and eotaxin subfamily chemokines was analysed in response to Dermatophagoides pteronyssinus allergen (D.p.) according to the presence of specific IgE to D.p., and investigated the mechanism underlying their LPS‐mediated regulation of these cytokines in response to the specific allergen. Peripheral blood cells (PBCs) from asthmatics with (group 1) or without (group 2) specific IgE to D.p. and from non‐asthmatics with (group 3) or without (group 4) were stimulated with D.p. or LPS. For LPS‐mediated inhibition of IL‐5 and eotaxin‐2 production, LPS‐induced cytokines were added to the D.p.‐stimulated PBCs. IL‐5 and eotaxin‐2, but not eotaxin‐1 and 3, were significantly increased by D.p.‐stimulated‐PBCs from group 1, while only eotaxin‐2 was elevated in group 3. Eotaxin‐2 production was found in monocytes and correlated with the level of specific IgE to D.p. LPS treatment resulted in the decrease in eotaxin‐2 and IL‐5 production by the D.p.‐stimulated PBCs. LPS‐induced IL‐10 completely inhibited D.p.‐stimulated production of eotaxin‐2 and IL‐5. The differential responses of the eotaxin family to specific antigens suggest that the predominant role of eotaxin‐2 and LPS may attenuate eosinophilic inflammation by inhibiting IL‐5 and eotaxin‐2 synthesis through IL‐10 production.

Association of IKBA gene polymorphisms with the development of asthma.

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.