Potential Role of Heme Oxygenase-1 in the Resolution of Experimentally Induced Colitis through Regulation of Macrophage Polarization

Background/Aims@#Heme oxygenase-1 (HO-1) plays a central role in cellular defense against inflammatory insults, and its induction in macrophages potentiates their efferocytic activity. In this study, we explored the potential role of macrophage HO-1 in the resolution of experimentally induced colitis. @*Methods@#To induce colitis, male C57BL/6 mice were treated with 2% dextran sulfate sodium (DSS) in the drinking water for 7 days. To investigate efferocytosis, apoptotic colon epithelial CCD 841 CoN cells were coincubated with bone marrow-derived macrophages (BMDMs). @*Results@#Administration of the HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blunted the resolution of DSS-induced intestinal inflammation and expression of the proresolving M2 macrophage marker CD206. BMDMs treated with apoptotic colonic epithelial cells showed significantly elevated expression of HO-1 and its regulator Nrf2. Under the same experimental conditions, the proportion of CD206-expressing macrophages was also enhanced. ZnPP treatment abrogated the upregulation of CD206 expression in BMDMs engulfing apoptotic colonic epithelial cells. This result was verified with BMDMs isolated from HO-1-knockout mice. BMDMs, when stimulated with lipopolysaccharide, exhibited increased expression of CD86, a marker of M1 macrophages.Coculture of lipopolysaccharide-stimulated BMDMs with apoptotic colonic epithelial cell debris dampened the expression of CD86 as well as the pro-inflammatory cytokines in an HO-1-dependent manner. Genetic ablation as well as pharmacologic inhibition of HO-1 significantly reduced the proportion of efferocytic BMDMs expressing the scavenger receptor CD36. @*Conclusions@#HO-1 plays a key role in the resolution of experimentally induced colitis by modulating the polarization of macrophages.

ADAM33 Polymorphisms Are Associated with Susceptibility to Systemic Lupus Erythematosus in a Korean Population

OBJECTIVE: The objective of this study is to assess whether genetic functional variants of disintegrin and metalloprotease 33 (ADAM33) are associated with susceptibility to systemic lupus erythematosus (SLE) in a Korean population. METHODS: We previously identified 48 single nucleotide polymorphisms (SNPs) in ADAM33. Six SNPs were selected with regard to the linkage disequilibrium pattern. An association study of ADAM33 was conducted in 190 patients with SLE and 469 control subjects. SNPs were genotyped using the TaqMan Real-time polymerase chain reaction method, and haplotype analyses of related variants were performed. RESULTS: All SNPs were in Hardy-Weinberg equilibrium. Significant associations were found between the ADAM33 polymorphisms and SLE at rs2787094 (adjusted odds ratio [OR] 1.88, 95% confidence interval [CI] 1.00 to 3.54; p<0.0001). The rs554743 polymorphism was associated with the presence of the immunoglobulin M anti-cardiolipin antibody (adjusted OR 0.29, 95% CI 0.10 to 0.83; p=0.021). CONCLUSION: ADAM33 polymorphisms were associated with susceptibility to SLE and development of clinical disease manifestations in a Korean population. Further study is warranted to clarify the role of ADAM33 in SLE pathogenesis.

Induction of heme oxygenase-1 with dietary quercetin reduces obesity-induced hepatic inflammation through macrophage phenotype switching

BACKGROUND/OBJECTIVES: Obesity-induced steatohepatitis accompanied by activated hepatic macrophages/Kupffer cells facilitates the progression of hepatic fibrinogenesis and exacerbates metabolic derangements such as insulin resistance. Heme oxyganase-1 (HO-1) modulates tissue macrophage phenotypes and thus is implicated in protection against inflammatory diseases. Here, we show that the flavonoid quercetin reduces obesity-induced hepatic inflammation by inducing HO-1, which promotes hepatic macrophage polarization in favor of the M2 phenotype. MATERIALS/METHODS: Male C57BL/6 mice were fed a regular diet (RD), high-fat diet (HFD), or HFD supplemented with quercetin (HF+Que, 0.5g/kg diet) for nine weeks. Inflammatory cytokines and macrophage markers were measured by ELISA and RT-PCR, respectively. HO-1 protein was measured by Western blotting. RESULTS: Quercetin supplementation decreased levels of inflammatory cytokines (TNFα, IL-6) and increased that of the anti-inflammatory cytokine (IL-10) in the livers of HFD-fed mice. This was accompanied by upregulation of M2 macrophage marker genes (Arg-1, Mrc1) and downregulation of M1 macrophage marker genes (TNFα, NOS2). In co-cultures of lipid-laden hepatocytes and macrophages, treatment with quercetin induced HO-1 in the macrophages, markedly suppressed expression of M1 macrophage marker genes, and reduced release of MCP-1. Moreover, these effects of quercetin were blunted by an HO-1 inhibitor and deficiency of nuclear factor E2-related factor 2 (Nrf2) in macrophages. CONCLUSIONS: Quercetin reduces obesity-induced hepatic inflammation by promoting macrophage phenotype switching. The beneficial effect of quercetin is associated with Nrf2-mediated HO-1 induction. Quercetin may be a useful dietary factor for protecting against obesity-induced steatohepatitis.

Overexpression of bone morphogenetic protein 4 in STO fibroblast feeder cells represses the proliferation of mouse embryonic stem cells in vitro

Embryonic stem cells (ESCs) can be propagated in vitro on feeder layers of mouse STO fibroblast cells. The STO cells secrete several cytokines that are essential for ESCs to maintain their undifferentiated state. In this study, we found significant growth inhibition of mouse ESCs (mESCs) cultured on STO cells infected with adenovirus containing a dominant-negative mutant form of IkappaB (rAd-dnIkappaB). This blockage of the NF-kappaB signal pathway in STO cells led to a significant decrease in [3H]thymidine incorporation and colony formation of mESCs. Expression profile of cytokines secreted from the STO cells revealed an increase in the bone morphogenetic protein4 (BMP4) transcript level in the STO cells infected with adenoviral vector encoding dominant negative IkappaB (rAd-dnIkappaB). These results suggested that the NF-kappaB signaling pathway represses expression of BMP4 in STO feeder cells. Conditioned medium from the rAd-dnIkappaB-infected STO cells also significantly reduced the colony size of mESCs. Addition of BMP4 prevented colony formation of mESCs cultured in the conditioned medium. Our finding suggested that an excess of BMP4 in the conditioned medium also inhibits proliferation of mESCs.

CO/HO-1 Induces NQO-1 Expression via Nrf2 Activation

BACKGROUND: Carbon monoxide (CO) is a cytoprotective and homeostatic molecule with important signaling capabilities in physiological and pathophysiological situations. CO protects cells/tissues from damage by free radicals or oxidative stress. NAD(P)H:quinone oxidoreductase (NQO1) is a highly inducible enzyme that is regulated by the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway, which is central to efficient detoxification of reactive metabolites and reactive oxygen species (ROS). METHODS: We generated NQO1 promoter construct. HepG2 cells were treated with CO Releasing Molecules-2 (CORM-2) or CO gas and the gene expressions were measured by RT-PCR, immunoblot, and luciferase assays. RESULTS: CO induced expression of NQO1 in human hepatocarcinoma cell lines by activation of Nrf2. Exposure of HepG2 cells to CO resulted in significant induction of NQO1 in dose- and time-dependent manners. Analysis of the NQO1 promoter indicated that an antioxidant responsible element (ARE)-containing region was critical for the CO-induced Nrf2-dependent increase of NQO1 gene expression in HepG2 cells. CONCLUSION: Our results suggest that CO-induced Nrf2 increases the expression of NQO1 which is well known to detoxify reactive metabolites and ROS.

Triptolide Inhibits the Proliferation of Immortalized HT22 Hippocampal Cells Via Persistent Activation of Extracellular Signal-Regulated Kinase-1/2 by Down-Regulating Mitogen-Activated Protein Kinase Phosphatase-1 Expression

OBJECTIVE: Triptolide (TP) has been reported to suppress the expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1), of which main function is to inactivate the extracellular signal-regulated kinase-1/2 (ERK-1/2), the p38 MAPK and the c-Jun N-terminal kinase-1/2 (JNK-1/2), and to exert antiproliferative and pro-apoptotic activities. However, the mechanisms underlying antiproliferative and pro-apoptotic activities of TP are not fully understood. The purpose of this study was to examine whether the down-regulation of MKP-1 expression by TP would account for antiproliferative activity of TP in immortalized HT22 hippocampal cells. METHODS: MKP-1 expression and MAPK phosphorylation were analyzed by Western blot. Cell proliferation was assessed by 3H-thymidine incorporation. Small interfering RNA (siRNA) against MKP-1, vanadate (a phosphatase inhibitor), U0126 (a specific inhibitor for ERK-1/2), SB203580 (a specific inhibitor for p38 MAPK), and SP600125 (a specific inhibitor for JNK-1/2) were employed to evaluate a possible mechanism of antiproliferative action of TP. RESULTS: At its non-cytotoxic dose, TP suppressed MKP-1 expression, reduced cell growth, and induced persistent ERK-1/2 activation. Similar growth inhibition and ERK-1/2 activation were observed when MKP-1 expression was blocked by MKP-1 siRNA and its activity was inhibited by vanadate. The antiproliferative effects of TP, MKP-1 siRNA, and vanadate were significantly abolished by U0126, but not by SB203580 or SP600125. CONCLUSION: Our findings suggest that TP inhibits the growth of immortalized HT22 hippocampal cells via persistent ERK-1/2 activation by suppressing MKP-1 expression. Additionally, this study provides evidence supporting that MKP-1 may play an important role in regulation of neuronal cell growth.

Heme Oxygenase-1: Its Therapeutic Roles in Inflammatory Diseases

Heme oxygenase (HO)-1 is an inducible enzyme that catalyzes the first and rate-limiting step in the oxidative degradation of free heme into ferrous iron, carbon monoxide (CO), and biliverdin (BV), the latter being subsequently converted into bilirubin (BR). HO-1, once expressed during inflammation, forms high concentrations of its enzymatic by-products that can influence various biological events, and this expression is proven to be associated with the resolution of inflammation. The degradation of heme by HO-1 itself, the signaling actions of CO, the antioxidant properties of BV/BR, and the sequestration of ferrous iron by ferritin all concertedly contribute to the anti-inflammatory effects of HO-1. This review focuses on the anti-inflammatory mechanisms of HO-1 actions and its roles in inflammatory diseases.

Heme Oxygenase-1: Its Therapeutic Roles in Inflammatory Diseases

Heme oxygenase (HO)-1 is an inducible enzyme that catalyzes the first and rate-limiting step in the oxidative degradation of free heme into ferrous iron, carbon monoxide (CO), and biliverdin (BV), the latter being subsequently converted into bilirubin (BR). HO-1, once expressed during inflammation, forms high concentrations of its enzymatic by-products that can influence various biological events, and this expression is proven to be associated with the resolution of inflammation. The degradation of heme by HO-1 itself, the signaling actions of CO, the antioxidant properties of BV/BR, and the sequestration of ferrous iron by ferritin all concertedly contribute to the anti-inflammatory effects of HO-1. This review focuses on the anti-inflammatory mechanisms of HO-1 actions and its roles in inflammatory diseases.

Polymorphisms of COTL1 gene identified by proteomic approach and their association with autoimmune disorders

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.

Polymorphisms of COTL1 gene identified by proteomic approach and their association with autoimmune disorders

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.

Association of TBX21 polymorphisms in a Korean population with rheumatoid arthritis

TBX21 (T-bet) is a member of the T-box family of transcriptional factors that contain a conserved DNA binding domain. TBX21 is a critical regulator of the commitment to the Th1 lineage and IFN-gamma production. Th1 and Th2 cells cross-regulate the differentiation of each other, and in this way TBX21 could be an attractive candidate gene for treating autoimmune disease such as rheumatoid arthritis (RA). In present study, we analyzed the genotypic frequencies of six polymorphisms of the TBX21 gene between the 367 RA patients and the 572 healthy controls. We showed that the g.-1514T>C and c.99C>G polymorphisms are suggestively associated with RA susceptibility. It is interesting that the genotypic frequencies of the TBX21 polymorphisms (g.-1514T>C and c.2103A>C) in the male RA patients were significantly different from the male control group (P = 0.0016 and 0.045, respectively). We also found that the g.-1514T>C and c.2103A>C polymorphisms of the TBX21 gene in the male RA patients have significant association with the levels of anti-CCP (P = 0.05) and rheumatoid factor (P = 0.03), respectively. These results suggest that the polymorphisms of the TBX21 gene might be associated with the susceptibility to male RA patients.

Identification of Human LRG1 Polymorphisms and Their Genetic Association with Rheumatoid Arthritis

Human leucine-rich alpha-2-glycoprotein 1 (LRG1 ) was first identified as a trace protein in human serum. The primary sequence of LRG1 includes repeated leucine residues and putative membrane-binding domains. But, there is no published information on the genetic variation of this gene. In this study, LRG1 was identified as one of several upregulated genes in RA patients. We examined the expression levels of LRG1 between an RA patient and a healthy control by RT-PCR and validated that LRG1 was highly expressed in RA patients compared with controls. We identified the possible variation sites and single nucleotide polymorphisms (SNPs) in the human LRG1 gene by direct sequencing and analyzed the association of genotype and allele frequencies between RA patients and a control group without RA. We further investigated the relationship between these polymorphisms and the level of RF or anti-CCP in RA patients. We identified a total of three SNPs (g.-678A> G, g.-404C>T and g.1427T>C) and two variation sites (g.-1198delA and g.-893delA) in the LRG1 gene. Our results suggest that polymorphisms of the LRG1 gene are not associated with the susceptibility of RA in the Korean population.

Effects of Heme Oxygenase-1 Inducer and Inhibitor on Experimental Autoimmune Uveoretinitis

PURPOSE: Experimental autoimmune uveoretinitis (EAU) is an animal model of posterior uveitis and heme oxygenase-1 (HO-1) is a well-known anti-oxidant factor. However, there is no report a protective role of HO-1 on EAU in vivo. To verify that HO-1 is induced in EAU by interphotoreceptor retinoid-binding protein (IRBP), that an HO-1 inducers ameliorates the associated inflammation, and that an HO-1 inhibitor exacerbates this inflammation. METHODS: Forty four Lewis rats were given either 40 mol/kg hemin or 40 mol/kg SnPP (tin protoporphyrin IX) by intraperitoneal injection and twenty two uveitis control rats were injected with 0.5 mL of saline once daily 5-20 days after IRBP immunization inducing EAU. Three normal control rats were used for Western blotting and ELISA assay of HO-1. The clinical uveitis signs of inflammation were scored in the three groups from 0 to 4 on alternate three days. To confirm the clinical results, histological and immunohistochemical stain of HO-1 were performed on the day of peak inflammation and Western blotting and ELISA assay of HO-1 were performed on 6th, 12th and 18th day after IRBP immunization. RESULTS: Hemin, an inducer of HO-1, ameliorated the clinical signs of EAU. In contrast, SnPP-treated rats show that the severity of the clinical sign were exacerbated at the peak period of the disease. These results are roughly compatible with histological, immunoblotting, and immunohistochemical evaluations and an ELISA assay of HO-1. CONCLUSIONS: We suggest that HO-1 plays an important protective role in EAU.

Roles of heme oxygenase-1 in curcumin-induced growth inhibition in rat smooth muscle cells

In vascular smooth muscle cells (VSMCs), induction of the heme oxygenase-1 (HO-1) confers vascular protection against cellular proliferation mainly via its up-regulation of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) that is involved in negative regulation of cellular proliferation. In the present study, we investigated whether the phytochemical curcumin and its metabolite tetrahydrocurcumin could induce HO-1 expression and growth inhibition in rat VSMCs and, if so, whether their antiproliferative effect could be mediated via HO-1 expression. At non-toxic concentrations, curcumin possessing two Michael-reaction acceptors induced HO-1 expression by activating antioxidant response element (ARE) through translocation of the nuclear transcription factor E2-related factor-2 (Nrf2) into the nucleus and also inhibited VSMC growth triggered by 5% FBS in a dose-dependent manner. In contrast, tetrahydrocurcumin lacking Michael-reaction acceptor showed no effect on HO-1 expression, ARE activation and VSMC growth inhibition. The antiproliferative effect of curcumin in VSMCs was accompanied by the increased expression of p21(WAF1/CIP1). Inhibition of VSMC growth and expression of p21(WAF1/CIP1) by curcumin were partially, but not completely, abolished when the cells were co- incubated with the HO inhibitor tin protoporphyrin. In human aortic smooth muscle cells (HASMCs), curcumin also inhibited growth triggered by TNF-alpha and increased p21(WAF1/CIP1) expression via HO-1-dependent manner. Our findings suggest that curcumin has an ability to induce HO-1 expression, presumably through Nrf2-dependent ARE activation, in rat VSMCs and HASMCs, and provide evidence that the antiproliferative effect of curcumin is considerably linked to its ability to induce HO-1 expression.

Association of FOXJ1 polymorphisms with systemic lupus erythematosus and rheumatoid arthritis in Korean population

The forkhead-box J1 (FOXJ1) transcription factor could suppress a spontaneous activation of T cells and B cells through an induction of IkappaBbeta that results in repression of NF-kappaB activity. In Foxj1 deficiency mice, systemic autoimmune inflammation is quite common symptom. Therefore, deregulated Foxj1 is supposed to be associated with autoimmune diseases and/or other inflammatory diseases. Previously, we identified that polymorphisms of human FOXJ1 gene (g.-460C>T, g.1805G>T and g.3375G>C) are associated with allergic rhinitis in a Korean population. In present study, we compared the genotype and allele frequencies of these SNPs between healthy controls and systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) patients. We also investigated the relationships between each genotype and the expression levels of anti-nuclear antibodies in SLE patients, and rheumatoid factor and anti-cyclic citrullinated peptide in RA patients. The frequencies of haplotypes constructed by these FOXJ1 SNPs were compared between controls and SLE (or RA) patients. The results of genotype and allele analysis showed that the prevalence of polymorphism g.3375G>C was associated with the susceptibility of SLE (P = 0.0072 and 0.0042, respectively). But no significant association was found with RA. In the haplotype analysis, however, the main CGG showed a weak association between controls and RA patients (P = 0.048).

Analysis of the variations in IL-28RA gene and their association with allergic rhinitis

IL-28RA is one of the important candidate genes for complex trait of genetic diseases, but there is no published information of the genetic variation in this gene. We scanned the seven exons and their boundary introns sequence of IL-28RA including the promoter regions to analyze genetic variation sites, and identified eighteen single nucleotide polymorphisms (SNPs) and two variation sites. We chose seven SNPs (g.-1193 A>C, g.-30 C>T, g.17654 C>T, g.27798 A>G, g.31265 C>T, g.31911 C>T and g.32349 G>A) of them for large sample size genotyping, and assessed the association of genotype and allele frequencies of these SNPs between allergic rhinitis patients and non-allergic rhinitis controls. We also compared the genotype frequencies between Korean controls and Han Chinese control or Korean Chinese control. We investigated the frequencies of haplotype constructed by these SNPs between allergic rhinitis patients and non-allergic rhinitis controls. Our results suggested that the g.32349 G>A polymorphism of IL-28RA might be associated with susceptibility to allergic rhinitis (P=0.032), but seems to have no relationship with serum total IgE levels. The haplotype frequencies by these SNPs also show significant association between controls and allergic rhinitis patients.

Comparative effects of curcuminoids on endothelial heme oxygenase-1 expression: ortho-methoxy groups are essential to enhance heme oxygenase activity and protection

Recently, it has been reported that curcumin, which is known as a potent antioxidant, acts as a non-stressful and non-cytotoxic inducer of the cytoprotective heme oxygenase (HO)-1. In this study, naturally occurring curcuminoids, such as pure curcumin, demethoxycurcumin (DMC) and bis-demethoxycurcumin (BDMC), were compared for their potential ability to modulate HO-1 expression and cytoprotective activity in human endothelial cells. All three curcuminoids could induce HO-1 expression and HO activity with differential levels. The rank order of HO activity was curcumin, DMC and BDMC. In comparison with endothelial protection against H2O2-induced cellular injury, cytoprotective capacity was found to be highest with curcumin, followed by DMC and BDMC. Interestingly, cytoprotective effects afforded by curcuminoids were considerably associated with their abilities to enhance HO activity. Considering that the main difference among the three curcuminoids is the number of methoxy groups (none for BDMC, one for DMC, and two for curcumin), the presence of methoxy groups in the ortho position on the aromatic ring was suggested to be essential to enhance HO-1 expression and cytoprotection in human endothelial cells. Our results may be useful in designing more efficacious HO-1 inducers which could be considered as promising pharmacological agents in the development of therapeutic approaches for the prevention or treatment of endothelial diseases caused by oxidative damages.

Association of the Human IL-28RA Gene Polymorphisms in a Korean Population with Asthma

IL-28RA is one of the important candidate genes for complex trait of genetic diseases, but there are only a few published results for this gene. Previously, we identified eighteen SNPs and two variation sites in the entire coding regions of IL-28RA including promoter regions, and suggested that the g.32349G > A polymorphism of IL-28RA might be associated with susceptibility to allergic rhinitis. In this study, we chose seven SNPs (g.-1193A > C, g.-30C > T, g.17654C > T, g.27798A > G, g.31265C > T, g.31911C > T and g.32349G > A) of IL-28RA, and attempted to find out whether these polymorphisms were furtherassociated with genetic predisposition of asthma. We analyzed the genotype and allele frequencies of IL-28RA polymorph isms between the asthma patients and healthy controls. We also investigated the frequencies of haplotype constructed by these SNPs between asthma patients and controls. Our results suggest that the polymorphisms of IL-28RA gene were not associated with susceptibility to asthma, and not with IgE production and eosinophil recruitment. The haplotype frequencies by these SNPs also not significantly associated between the healthy controls and asthma patients. This result indicates that the IL-2BRA polymorphisms might be not associated withasthma susceptibility.

Putative association of RUNX1 polymorphisms with IgE levels in a Korean population

RUNX1, a member of the runt domain gene family of transcription factors, encodes a heterodimeric transcription factor and regulates the expression of various genes related to hematopoiesis and myeloid differentiation. RUNX1 has been one of the target genes for research into various autoimmune diseases due to its properties as a transcription factor and functional distribution for chromosomal translocation. In an effort to identify additional gene polymorphisms in which variants have been implicated in asthma, we investigated the genetic polymorphisms in RUNX1 to evaluate it as a potential candidate gene for a host genetic study of asthma and IgE production. We identified 19 sequence variants by direct DNA sequencing in 24 individuals of which four common variants were selected for genotyping in our asthma cohort (1,055 asthmatic patients, 384 normal controls). Using logistic regression analysis for association with the risk of asthma, while controlling for age, gender, and smoking status as covariates, no significant associations with the risk of asthma were detected. However, two polymorphisms in the promoter region (-2084G>C and -1282G>A) showed a marginal association with total IgE levels (0.03 and 0.03 in recessive models, respectively). Our findings suggest that polymorphisms in RUNX1 might be one of the genetic factors for the regulation of IgE production.

The association of eotaxin-2 and eotaxin-3 gene polymorphisms in a Korean population with ulcerative colitis

The eotaxin gene family (eotaxin, eotaxin-2 and eotaxin-3) have been implicated in the recruitment of eosinophils, basophiles and helper T (Th) 2 lymphocytes that is a central aspect of allergic disease. We previously suggested that Eo2+179T>C and Eo2 +275C>T of the eotaxin-2, and Eo3 +2497T>G of the eotaxin-3 were significantly associated with susceptibility to asthma. To determine whether the single nucleotide polymorphisms (SNPs) of eotaxin-2 and eotaxin-3 gene family are associated with the susceptibility of ulcerative colitis (UC), we analyzed the genotype of 119 patients with UC and 303 controls using single-base extension (SBE) method. We also calculated the haplotype frequencies among Eo2 +179T>C and Eo2 +275C >T of the eotaxin-2 and Eo3 +2497T>G of the eotaxin-3 in both control and UC patients. The genotype frequency of Eo2 +179T>C and Eo2 +275C>T between UC patients and controls were significantly different (P=0.006 and 0.022, respectively). The genotype and allele frequencies of EoA2497T>G in UC patients were not significantly different from those in the controls without UC patients. Our results suggest that Eo2 +179T>C and Eo2 +275C>T of eotaxin-2 might be associated with the susceptibility of UC.