A polymorphism in the human UGRP1 gene promoter that regulates transcription is associated with an increased risk of asthma

Emerging role of an immunomodulatory protein secretoglobin 3A2 in human diseases

Secretoglobin (SCGB) 3A2 was first identified in 2001 as a protein exhibiting similarities in amino acid sequence and gene structure to SCGB1A1, a multi-functional cytokine-like molecule highly expressed in airway epithelial Club cells that was the first identified and extensively studied member of the SCGB gene superfamily. SCGB3A2 is a small secretory protein of ~10 kDa that forms a dimer and a tetramer. SCGB3A2 is predominantly expressed in airway epithelial Club cells, and has anti-inflammatory, growth factor, anti-fibrotic, and anti-cancer activities that influence various lung diseases. This review summarizes the current understanding of SCGB3A2 biological functions and its role in human diseases with emphasis on its mechanisms of actions and signaling pathway.

Assessment of the Feasibility of a Future Integrated Larger-Scale Epidemiological Study to Evaluate Health Risks of Air Pollution Episodes in Children

Air pollution exposure can lead to exacerbation of respiratory disorders in children. Using sensitive biomarkers helps to assess the impact of air pollution on children’s respiratory health and combining protein, genetic and epigenetic biomarkers gives insights on their interrelatedness. Most studies do not contain such an integrated approach and investigate these biomarkers individually in blood, although its collection in children is challenging. Our study aimed at assessing the feasibility of conducting future integrated larger-scale studies evaluating respiratory health risks of air pollution episodes in children, based on a qualitative analysis of the technical and logistic aspects of a small-scale field study involving 42 children. This included the preparation, collection and storage of non-invasive samples (urine, saliva), the measurement of general and respiratory health parameters and the measurement of specific biomarkers (genetic, protein, epigenetic) of respiratory health and air pollution exposure. Bottlenecks were identified and modifications were proposed to expand this integrated study to a higher number of children, time points and locations. This would allow for non-invasive assessment of the impact of air pollution exposure on the respiratory health of children in future larger-scale studies, which is critical for the development of policies or measures at the population level.

Secretoglobins in the big picture of immunoregulation in airway diseases

The proteins of the secretoglobin (SCGB) family are expressed by secretory tissues of barrier organs. They are embedded in immunoregulatory and anti-inflammatory processes of airway diseases. This review particularly illustrates the immune regulation of SCGBs by cytokines and their implication in the pathophysiology of airway diseases. The biology of SCGBs is a complex topic of increasing importance, as they are highly abundant in the respiratory tract and can also be detected in malignant tissues and as elements of immune control. In addition, SCGBs react to cytokines, they are embedded in Th1 and Th2 immune responses, and they are expressed in a manner dependent on cell maturation. The big picture of the SCGB family identifies these factors as critical elements of innate immune control at the epithelial barriers and highlights their potential for diagnostic assessment of epithelial activity. Some members of the SCGB family have so far only been superficially examined, but have high potential for translational research.

Potential Metabolic Biomarkers in Adult Asthmatics

Asthma is the most common chronic airway inflammation, with multiple phenotypes caused by complicated interactions of genetic, epigenetic, and environmental factors. To date, various determinants have been suggested for asthma pathogenesis by a new technology termed omics, including genomics, transcriptomics, proteomics, and metabolomics. In particular, the systematic analysis of all metabolites in a biological system, such as carbohydrates, amino acids, and lipids, has helped identify a novel pathway related to complex diseases. These metabolites are involved in the regulation of hypermethylation, response to hypoxia, and immune reactions in the pathogenesis of asthma. Among them, lipid metabolism has been suggested to be related to lung dysfunction in mild-to-moderate asthma. Sphingolipid metabolites are an important mediator contributing to airway inflammation in obese asthma and aspirin-exacerbated respiratory disease. Although how these molecular variants impact the disease has not been completely determined, identification of new causative factors may possibly lead to more-personalized and precise pathway-specific approaches for better diagnosis and treatment of asthma. In this review, perspectives of metabolites related to asthma and clinical implications have been highlighted according to various phenotypes.

Novel computational analysis of large transcriptome datasets identifies sets of genes distinguishing chronic obstructive pulmonary disease from healthy lung samples

Chronic obstructive pulmonary disease (COPD) kills over three million people worldwide every year. Despite its high global impact, the knowledge about the underlying molecular mechanisms is still limited. In this study, we aimed to extend the available knowledge by identifying a small set of COPD-associated genes. We analysed different publicly available gene expression datasets containing whole lung tissue (WLT) and airway epithelium (AE) samples from over 400 human subjects for differentially expressed genes (DEGs). We reduced the resulting sets of 436 and 663 DEGs using a novel computational approach that utilises a random depth-first search to identify genes which improve the distinction between COPD patients and controls along the first principle component of the data. Our method identified small sets of 10 and 15 genes in the WLT and AE, respectively. These sets of genes significantly (p < 10^–20) distinguish COPD patients from controls with high fidelity. The final sets revealed novel genes like cysteine rich protein 1 (CRIP1) or secretoglobin family 3A member 2 (SCGB3A2) that may underlie fundamental molecular mechanisms of COPD in these tissues.

Selection of a Noninvasive Source of Human DNA Envisaging Genotyping Assays in Epidemiological Studies: Urine or Saliva?

Genetic epidemiology requires an appropriate approach to measure genetic variation within the population. The aim of this study was to evaluate the characteristics and genotyping results of DNA extracted from 2 human DNA sources, selected for their rapid and noninvasive sampling, and the use of simple and standardized protocols that are essential for large-scale epidemiologic studies. Saliva and urine samples were collected at the same day from 20 subjects aged 9-10 yr. Genomic DNA was extracted using commercial kits. Quantitative and qualitative evaluation was done by assessing the yield, the purity, and integrity of the extracted DNA. As a proof-of-concept, genotyping was performed targeting CC16 A38G and uteroglobin-related protein 1 (UGRP1)-112G/A. Saliva was found to provide the highest yield and concentration of total DNA extracted. Salivary DNA showed higher purity and a significantly less degraded state compared to urinary DNA. Consequently, the salivary DNA gave better genotyping results than urinary DNA. Therefore, if the choice exists, saliva is the preferred noninvasive matrix for genotyping purposes in large-scale genetic epidemiologic studies. Only in particular cases using urine could nevertheless be considered useful, although specific limitations need to be taken into account.

Association of Ugrp2 gene polymorphisms with adenoid hypertrophy in the pediatric population

INTRODUCTION

Adenoid hypertrophy is a condition that presents itself as the chronic enlargement of adenoid tissues; it is frequently observed in the pediatric population. The Ugrp2 gene, a member of the secretoglobin superfamily, encodes a low-molecular weight protein that functions in the differentiation of upper airway epithelial cells. However, little is known about the association of Ugrp2 genetic variations with adenoid hypertrophy.

OBJECTIVE

The aim of this study is to investigate the association of single nucleotide polymorphisms in the Ugrp2 gene with adenoid hypertrophy and its related phenotypes.

METHODS

A total of 219 children, comprising 114 patients suffering from adenoid hypertrophy and 105 healthy patients without adenoid hypertrophy, were enrolled in this study. Genotypes of the Ugrp2 gene were determined by DNA sequencing.

RESULTS

We identified four single nucleotide polymorphisms (IVS1-189G>A, IVS1-89T>G, c.201delC, and IVS2-15G>A) in the Ugrp2 gene. Our genotype analysis showed that the Ugrp2 (IVS1-89T>G) TG and (c.201delC) CdelC genotypes and their minor alleles were associated with a considerable increase in the risk of adenoid hypertrophy compared with the controls (p=0.012, p=0.009, p=0.013, and p=0.037, respectively). Furthermore, Ugrp2 (GTdelCG, GTdelCA) haplotypes were significantly associated with adenoid hypertrophy (four single nucleotide polymorphisms ordered from 5' to 3'; p=0.0001). Polymorfism-Polymorfism interaction analysis indicated a strong interaction between combined genotypes of the Ugrp2 gene contributing to adenoid hypertrophy, as well as an increased chance of its diagnosis (p<0.0001). In addition, diplotypes carrying the mutant Ugrp2 (c.201delC) allele were strongly associated with an increased risk of adenoid hypertrophy with asthma and with allergies (p=0.003 and p=0.0007, respectively).

CONCLUSION

Some single nucleotide polymorphisms and their combinations in the Ugrp2 gene are associated with an increased risk of developing adenoid hypertrophy. Therefore, we tried to underline the importance of genetic factors associated with adenoid hypertrophy and its related clinical phenotypes.

Association Between Secretoglobin Family 3A Member 2 (SCGB3A2) Gene Polymorphisms and Asthma in a Korean Population

Background

Secretoglobin family 3A member 2 (SCGB3A2) plays an important role in secreting lung surfactant protein, which is a downstream target of thyroid transcription factor.

Material/Methods

We investigated whether single-nucleotide polymorphisms (SNPs) of SCGB3A2 gene contribute to susceptibility to asthma. To explore this possible association, 2 promoter SNPs (rs6882292, 659 G/A and rs1368408, −112 G/A) and missense SNP (rs151333009, stop codon) were tested in SCGB3A2 gene in 101 asthma patients and 377 healthy control subjects. SNPStats was used to obtain odds ratio (OR), 95% confidence intervals (CI), and P value adjusted for age and sex as covariables. Logistic regression method in each model (dominant, recessive, and log-additive) was applied to analyze genetic data.

Results

rs151333009 SNP showed a monomorphic genotype. Two promoter SNPs (rs6882292, −659 G/A and rs1368408, −112 G/A) showed significant association with asthma (rs6882292, OR=2.66, 95% CI=1.42–5.01, p=0.0033 in dominant model, OR=2.45, 95% CI=1.33–4.54, p=0.0055 in log-additive model; rs1368408, OR=1.59, 95% CI=1.02–2.49, p=0.041 in dominant model, OR=3.02, 95% CI=1.15–7.90, p=0.03 in recessive model, OR=1.63, 95% CI=1.63, 95% CI=1.12–2.37, p=0.012 in log-additive model).

Conclusions

These results suggest that the promoter SNPs (rs6882292 and rs1368408) of SCGB3A2 gene may contribute to susceptibility to asthma in a Korean population.

Secretoglobin Superfamily Protein SCGB3A2 Alleviates House Dust Mite-Induced Allergic Airway Inflammation in Mice

BACKGROUND

Secretoglobin (SCGB) 3A2, a novel, lung-enriched, cytokine-like, secreted protein of small molecular weight, was demonstrated to exhibit various biological functions including anti-inflammatory, antifibrotic and growth-factor activities. Anti-inflammatory activity was uncovered using the ovalbumin-induced allergic airway inflammation model. However, further validation of this activity using knockout mice in a different allergic inflammation model is necessary in order to establish the antiallergic inflammatory role for this protein.

METHODS

Scgb3a2-null (Scgb3a2-/-) mice were subjected to nasal inhalation of Dermatophagoides pteronyssinus extract for 5 days/week for 5 consecutive weeks; control mice received nasal inhalation of saline as a comparator. Airway inflammation was assessed by histological analysis, the number of inflammatory cells and various Th2-type cytokine levels in the lungs and bronchoalveolar lavage fluids by qRT-PCR and ELISA, respectively.

RESULTS

Exacerbated inflammation was found in the airway of Scgb3a2-/- mice subjected to house dust mite (HDM)-induced allergic airway inflammation compared with saline-treated control groups. All the inflammation end points were increased in the Scgb3a2-/- mice. The Ccr4 and Ccl17 mRNA levels were higher in HDM-treated lungs of Scgb3a2-/- mice than wild-type mice or saline-treated Scgb3a2-/- mice, whereas no changes were observed for Ccr3 and Ccl11 mRNA levels.

CONCLUSIONS

These results demonstrate that SCGB3A2 has an anti-inflammatory activity in the HDM-induced allergic airway inflammation model, in which SCGB3A2 may modulate the CCR4-CCL17 pathway. SCGB3A2 may provide a useful tool to treat allergic airway inflammation, and further studies on the levels and function of SCGB3A2 in asthmatic patients are warranted.

Current trend of annotating single nucleotide variation in humans--A case study on SNVrap

As high throughput methods, such as whole genome genotyping arrays, whole exome sequencing (WES) and whole genome sequencing (WGS), have detected huge amounts of genetic variants associated with human diseases, function annotation of these variants is an indispensable step in understanding disease etiology. Large-scale functional genomics projects, such as The ENCODE Project and Roadmap Epigenomics Project, provide genome-wide profiling of functional elements across different human cell types and tissues. With the urgent demands for identification of disease-causal variants, comprehensive and easy-to-use annotation tool is highly in demand. Here we review and discuss current progress and trend of the variant annotation field. Furthermore, we introduce a comprehensive web portal for annotating human genetic variants. We use gene-based features and the latest functional genomics datasets to annotate single nucleotide variation (SNVs) in human, at whole genome scale. We further apply several function prediction algorithms to annotate SNVs that might affect different biological processes, including transcriptional gene regulation, alternative splicing, post-transcriptional regulation, translation and post-translational modifications. The SNVrap web portal is freely available at http://jjwanglab.org/snvrap.

Exploring the function of genetic variants in the non-coding genomic regions: approaches for identifying human regulatory variants affecting gene expression

Understanding the genetic basis of human traits/diseases and the underlying mechanisms of how these traits/diseases are affected by genetic variations is critical for public health. Current genome-wide functional genomics data uncovered a large number of functional elements in the noncoding regions of human genome, providing new opportunities to study regulatory variants (RVs). RVs play important roles in transcription factor bindings, chromatin states and epigenetic modifications. Here, we systematically review an array of methods currently used to map RVs as well as the computational approaches in annotating and interpreting their regulatory effects, with emphasis on regulatory single-nucleotide polymorphism. We also briefly introduce experimental methods to validate these functional RVs.

The association of SCGB3A2 polymorphisms with the risk of Graves' disease: a meta-analysis

The aim of this study is to assess the association of the SCGB3A2 -112G>A promoter polymorphism with Graves' disease(GD) using a meta-analysis. Relevant studies were identified using PubMed and EMBASE electronic databases. A meta-analysis of relevant studies was performed. This meta-analysis included four case-control studies, containing 6,913 GD cases (Caucasian 3904, Han 3009) and 7,185 controls(Caucasian 4155, Han 3030). The combined results showed a significant difference in genotype distribution (-112A/G) between GD and control populations (A vs. G P = 1.53 × 10(-7); GG vs. AA+AG P = 6.78 × 10(-9)). Meta-analysis was performed using a fixed-effects model. Under the dominant model (GG/AA + GA), the AA and GA genotypes were significantly associated with GD (pooled OR = 1.24, 95 % CI 1.12-1.37). When the two European studies are combined, the AA and GA genotypes were also significantly associated with GD (pooled OR = 1.29, 95 % CI 1.20-1.39). This meta-analysis suggests that SCGB3A2 polymorphism at positions -112G>A was associated with GD both in Chinese and Caucasian population.

Association between the -112G/A polymorphism of uteroglobulin-related protein 1 gene and asthma risk: A meta-analysis

The aim of this study was to investigate the correlation between the -112G/A polymorphism of the uteroglobulin-related protein 1 (UGRP1) gene and asthma risk using meta-analysis. PubMed, BIOSIS Previews and EBSCOhost were searched, and data were extracted independently by two reviewers. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the strength of the associations. Statistical analysis was performed using Review Manager 5.2 and STATA 11.0 software. Six studies, involving 816 cases and 1,165 controls, were included in the analysis. The meta-analysis showed a significant correlation between the UGRP1-112G/A polymorphism and asthma for AA versus GG (P=0.01) and AA versus GA/GG (P=0.02). Furthermore, stratification by ethnicity revealed a significant correlation between the -112G/A polymorphism and asthma for A versus G (P=0.02), AA versus GG (P=0.01) and AA versus GA/GG (P=0.03) in Asians, but not in Caucasians. When stratified by atopy, a significant correlation was observed for A versus G (P=0.02) and AA/GA versus GG (P=0.04) in the mixed group. No correlation was observed for age stratification. Results of the current meta-analysis indicate that the -112G/A polymorphism of the UGRP1 gene is likely to contribute to asthma risk, particularly in the Asian population.

Uteroglobulin-related protein 1 and severity of respiratory syncytial virus infection in children admitted to hospital

There are several reports suggesting that genetic factors contribute to the severity of infection with the respiratory syncytial virus (RSV). Infants hospitalized with lower respiratory tract infection (LRTI) due to RSV are at a significantly increased risk for both recurrent wheezing and childhood asthma. Uteroglobin-related protein 1 (UGRP1) is a secretory protein expressed in the airways, and speculated to have anti-inflammatory activity. The presence of the -112G/A polymorphism in the UGRP1 promoter was found to have a significant correlation with asthma phenotype. Also plasma UGRP1 levels were shown to be associated both with this polymorphism and the severity of asthma. The study population consisted of 62 previously healthy infants, ≤12 months of age, who were hospitalized with RSV LRTI, and a control group of 99 healthy adults. Genotyping was performed by restriction fragment length polymorphism. UGRP1 serum levels were determined using ELISA. There were no significant differences in the overall distribution of UGRP1 -112G/A polymorphism genotypes or alleles between the hospitalized infants and healthy adults. A comparison of serum UGRP1 concentration measured at the time of admission and discharge between patients with and without the -112A allele revealed that there was no relation between the presence of the -112A allele and serum UGRP1 in hospitalized infants with RSV infection. Furthermore, there was no relationship between severity of RSV infection and genotype or serum UGRP1 concentration. These results suggest that UGRP1 does not have a major role in the development of severe RSV infection.

The genetic basis of graves' disease

The presented comprehensive review of current knowledge about genetic factors predisposing to Graves’ disease (GD) put emphasis on functional significance of observed associations. In particular, we discuss recent efforts aimed at refining diseases associations found within the HLA complex and implicating HLA class I as well as HLA-DPB1 loci. We summarize data regarding non-HLA genes such as PTPN22, CTLA4, CD40, TSHR and TG which have been extensively studied in respect to their role in GD. We review recent findings implicating variants of FCRL3 (gene for FC receptor-like-3 protein), SCGB3A2 (gene for secretory uteroglobin-related protein 1- UGRP1) as well as other unverified possible candidate genes for GD selected through their documented association with type 1 diabetes mellitus: Tenr–IL2–IL21, CAPSL (encoding calcyphosine-like protein), IFIH1(gene for interferon-induced helicase C domain 1), AFF3, CD226 and PTPN2. We also review reports on association of skewed X chromosome inactivation and fetal microchimerism with GD. Finally we discuss issues of genotype-phenotype correlations in GD.

Update of the human secretoglobin (SCGB) gene superfamily and an example of 'evolutionary bloom' of androgen-binding protein genes within the mouse Scgb gene superfamily

The secretoglobins (SCGBs) comprise a family of small, secreted proteins found in animals exclusively of mammalian lineage. There are 11 human SCGB genes and five pseudogenes. Interestingly, mice have 68 Scgb genes, four of which are highly orthologous to human SCGB genes; the remainder represent an 'evolutionary bloom' and make up a large gene family represented by only six counterparts in humans. SCGBs are found in high concentrations in many mammalian secretions, including fluids of the lung, lacrimal gland, salivary gland, prostate and uterus. Whereas the biological activities of most individual SCGBs have not been fully characterised, what already has been discovered suggests that this family has an important role in the modulation of inflammation, tissue repair and tumorigenesis. In mice, the large Scgb1b and Scgb2b gene families encode the androgen-binding proteins, which have been shown to play a role in mate selection. Although much has been learned about SCGBs in recent years, clearly more research remains to be done to allow a better understanding of the roles of these proteins in human health and disease. Such information is predicted to reveal valuable novel drug targets for the treatment of inflammation, as well as designing biomarkers that might identify tissue damage or cancer.

Variation in Uteroglobin-Related Protein 1 (UGRP1) gene is associated with allergic rhinitis in Singapore Chinese

Background

Uteroglobin-Related Protein 1 (UGRP1) is a secretoglobulin protein which has been suggested to play a role in lung inflammation and allergic diseases. UGRP1 has also been shown to be an important pneumoprotein, with diagnostic potential as a biomarker of lung damage. Previous genetic studies evaluating the association between variations on UGRP1 and allergic phenotypes have yielded mixed results. The aim of this present study was to identify genetic polymorphisms in UGRP1 and investigate if they were associated with asthma and allergic rhinitis in the Singapore Chinese population.

Methods

Resequencing of the UGRP1 gene was conducted on 40 randomly selected individuals from Singapore of ethnic Chinese origin. The polymorphisms identified were then tagged and genotyped in a population of 1893 Singapore Chinese individuals. Genetic associations were evaluated in this population comparing 795 individuals with allergic rhinitis, 718 with asthma (of which 337 had both asthma and allergic rhinitis) and 717 healthy controls with no history of allergy or allergic diseases.

Results

By resequencing the UGRP1 gene within our population, we identified 11 novel and 16 known single nucleotide polymorphisms (SNPs). TagSNPs were then genotyped, revealing a significant association between rs7726552 and allergic rhinitis (Odds Ratio: 0.81, 95% Confidence Interval: 0.66-0.98, P = 0.039). This association remained statistically significant when it was analyzed genotypically or when stratified according to haplotypes. When variations on UGRP1 were evaluated against asthma, no association was observed.

Conclusion

This study documents the association between polymorphisms in UGRP1 and allergic rhinitis, suggesting a potential role in its pathogenesis.

The cytokine-driven regulation of secretoglobins in normal human upper airway and their expression, particularly that of uteroglobin-related protein 1, in chronic rhinosinusitis

Background

The involvement of secretoglobins (SCGBs) other than SCGB1A1 (Clara cell 10-kDa protein, CC10) in human airway diseases remains unexplored. Among those SCGBs, SCGB3A2 (uteroglobin-related protein 1, UGRP1) is particularly interesting, given its structure and function similarities with SCGB1A1 (CC10). The aim of this study was to investigate the expression regulation of SCGBs other than SCGB1A1 (CC10) in human upper airway, and their potential involvement, particularly that of SCGB3A2 (UGRP1), in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP).

Methods

Eight SCGB family members including SCGB3A2 (UGRP1), SCGB1C1 (ligand binding protein RYD5), SCGB1D1 (lipophilin A), SCGB1D2 (lipophilin B), SCGB1D4 (interferon-γ inducible SCGB), SCGB2A1 (mammaglobin 2), SCGB2A2 (mammaglobin 1), and SCGB3A1 (uteroglobin-related protein 2) were studied. The regulation of SCGBs mRNA expression in normal nasal mucosa by proinflammatory, Th1, and Th2 cytokines was studied through nasal explant culture. SCGBs mRNA expression levels in CRSsNP and CRSwNP patients and controls were compared. The mRNA levels were detected by means of quantitative reverse transcriptase-polymerase chain reaction. The protein expression of SCGB3A2 (UGRP1) was analyzed using immunohistochemistry.

Results

The expression of SCGBs except SCGB1D2 (lipophilin B) could be found in upper airway and be differentially regulated by different cytokines. SCGB3A2 (UGRP1) mRNA expression was induced by Th1 cytokine, but suppressed by proinflammatory and Th2 cytokines. SCGBs mRNA expression was altered in CRS; particularly, SCGB3A2 (UGRP1) protein and mRNA expression was markedly decreased in both CRSsNP and CRSwNP and its protein levels inversely correlated with the number of total infiltrating cells, preoperative sinonasal CT scores, and postoperative endoscopy and symptom scores.

Conclusion

SCGBs except SCGB1D2 (lipophilin B) are expressed in human upper airway and their expression can be differentially regulated by inflammatory cytokines. SCGBs mRNA expression is altered in CRS. Reduced production of UGRP1, which is likely due, at least in part, to a local cytokine environment, may contribute to the hyper-inflammation in CRS and correlates with response to surgery.

The -112G>A polymorphism of the secretoglobin 3A2 (SCGB3A2) gene encoding uteroglobin-related protein 1 (UGRP1) increases risk for the development of Graves' disease in subsets of patients with elevated levels of immunoglobulin E

The human secretoglobin 3A2 (SCGB3A2) gene encoding secretory uteroglobin-related protein 1 (UGRP1) resides on the chromosome region 5q31-33 that harbors a susceptibility locus to several autoimmune and inflammatory diseases, including asthma and Graves' disease (GD). Recently, association between the marker rs1368408 (-112G >A), located in the promoter region of the SCGB3A2 gene, and susceptibility to GD was found in Chinese and UK Caucasians. The study aim was to evaluate whether this polymorphism confers GD susceptibility in a large population cohort comprising 1,474 Russian GD patients and 1,619 controls. The marker rs1368408 was studied using a TaqMan allele discrimination assay. Serum levels of UGRP1 and immunoglobulin E (IgE) were assessed using enzyme-linked immunosorbent assay (ELISA) analyses. Association between the allele A of SCGB3A2 and a higher risk of GD (odds ratio [OR] = 1.33, P = 2.9 × 10(-5)) was shown. Both affected and non-affected carriers of the higher risk genotype A/A had significantly decreased levels of serum UGRP1 compared to the subjects homozygous for G/G (93 ± 37 pg/ml vs. 132 ± 45 pg/ml, P = 0.0011 for GD patients; 77 ± 28 pg/ml vs. 119 ± 33 pg/ml, P = 0.0019 for controls). Serum IgE levels were significantly higher in non-affected subjects homozygous for A/A compared to control individuals homozygous for G/G (153 ± 46 IU/ml vs. 122 ± 40 IU/ml, P = 0.0095). Our data suggest that the carriage of the SCGB3A2 -112A/A variant increases the risk for GD in subsets of patients with elevated levels of IgE, a hallmark of allergic asthma. Therefore, the SCGB3A2 -112G >A polymorphism may be considered as a likely marker linking susceptibility to allergy/asthma and GD on chromosome 5q31-33.

Expression of secretoglobin3A2 (SCGB3A2) in primary pulmonary carcinomas

Secretoglobin (SCGB) 3A2 is a downstream target gene for the thyroid transcription factor-1 (TITF1). SCGB3A2 plays a role as an anti-inflammatory agent, however, its role in primary pulmonary carcinomas has not been examined. We assessed immunohistochemical expression of SCGB3A2 in primary pulmonary carcinomas and evaluated the correlation between the expression and histopathological phenotypes and prognosis. One hundred and fifty-six primary lung cancers undergone for surgical resection were examined. The percentages of SCGB3A2 positive cells were scored and tumors had immunoreactivity in more than 10% of tumor cells were considered positive for SCGB3A2. Overall reactivity for SCGB3A2 was observed in 116 (74.4%) of 156 primary lung cancers. SCGB3A2 was predominantly expressed in adenocarcinomas (86.5%), compared with squamous cell carcinomas (50.0%) and small cell carcinomas (42.9%). The expression in papillary adenocarcinomas was seen at higher frequency than that in tubular adenocarcinomas. There was no significant relationship between SCGB3A2 expression and tumor differentiation, and pathological stage. Positive expression of SCGB3A2 was not associated with better survival rate. SCGB3A2 expression in primary pulmonary carcinomas is high, especially in adenocarcinomas. Our results indicate that SCGB3A2 has a potential to be a specific and useful marker for primary pulmonary adenocarcinomas.

Role of secretoglobin 3A2 in lung development

RATIONALE

Secretoglobin 3A2 (SCGB3A2) was originally identified as a downstream target in lung for the homeodomain transcription factor NKX2-1, whose null mutation resulted in severely hypoplastic lungs. A very low level of SCGB3A2 is expressed in lungs at Embryonic Day (E) 11.5 during mouse development, which markedly increases by E16.5, the time when lung undergoes dramatic morphologic changes, suggesting that SCGB3A2 may be involved in lung development in addition to a known role in lung inflammation.

OBJECTIVES

To determine whether SCGB3A2 plays a role in lung development.

METHODS

To assess a potential role for SCGB3A2 during early lung development, wild-type and Nkx2-1-null fetal lungs of early developmental stages were subjected to ex vivo organ culture in the presence of SCGB3A2. Nkx2-1-null fetuses were exposed to SCGB3A2 during early organogenesis period through intravenous administration of this protein to Nkx2-1-heterozygous pregnant females carrying these null fetuses. Cultured lungs and fetal lungs were subjected to histologic and immunohistochemical analyses. To assess a role for SCGB3A2 in late lung development, SCGB3A2 was administered to pregnant wild-type females during mid- to late organogenesis stages, and the preterm pups and/or their lungs were evaluated for extent of maturity using breathing motion, gross morphology and histology of lungs, expression of gestational stage-specific genes, and phospholipid profiles.

MEASUREMENTS AND MAIN RESULTS

SCGB3A2 significantly promoted both early and late stages of lung development.

CONCLUSIONS

SCGB3A2 is a novel growth factor in lung.

Environmental tobacco smoke and interleukin 4 polymorphism (C-589T) gene: environment interaction increases risk of wheezing in African-American infants

OBJECTIVES

To determine whether infants exposed to environmental tobacco smoke (ETS) having the interleukin 4 (IL-4) or interleukin 13 (IL-13) gene polymorphisms were at increased risk of wheezing.

STUDY DESIGN

A birth cohort of 758 infants was evaluated annually by a questionnaire, physical examination, and skin prick testing. DNA samples from 560 children were genotyped for IL-4 C-589T and IL-13 C-1112T. The relationship of ETS exposure and genotype with the outcome of wheezing was analyzed.

RESULTS

At the time of evaluation, mean age was 13.4 +/- 2.2 months. The prevalence of sensitization was 29%, and wheezing without a cold was 26.2%. The interaction of ETS exposure and the CT/TT genotypes for IL-4 C-589T showed a significant association with wheezing (odds ratio: 10.84; 95% confidence interval: 1.12-104.64, P = .04) in African-American infants.

CONCLUSIONS

In African-American infants with a family history of atopy, the interaction of ETS and IL-4 C-589T demonstrated a 10-fold risk associated with wheezing without a cold.

Plasma UGRP1 levels associate with promoter G-112A polymorphism and the severity of asthma

BACKGROUND

Uteroglobin-related protein 1 (UGRP1) is a secretory protein expressed in the airways and is speculated to have anti-inflammatory activity. In the mouse, its gene expression is down-regulated by interleukin (IL)-5 and -9, and up-regulated by IL-10. However, the precise role of UGRP1 in human inflammatory airway diseases such as asthma has not been clarified. The objectives of this study were to establish an ELISA system to quantify UGRP1 protein, and to examine whether plasma UGRP1 levels are associated with the G-112A polymorphism, asthma susceptibility, and its severity.

METHODS

152 asthma patients and 103 normal controls were involved in this study. Mice were immunized with recombinant UGRP1 and hybridoma cell lines were established. A sandwich ELISA system was established by using two monoclonal antibodies recognizing different epitopes. Plasma UGRP1 levels were measured with the ELISA system and the G-112A allele was detected by using real-time PCR.

RESULTS

An ELISA system was established that allowed determination of UGRP1 levels within the range of 9.6-1250 pg/ml. The mean plasma UGRP1 levels for subjects with -112A allele were significantly lower than those without it (p = 0.025). Although there was no significant difference in the plasma UGRP1 levels between asthma patients and controls (p = 0.13), severe asthma patients without oral corticosteroid had significantly lower plasma UGRP1 levels compared to mild- or moderate- asthma patients and controls (p = 0.004, 0.03 and 0.003, respectively).

CONCLUSIONS

The ELISA system for quantifying UGRP1 protein was established, and plasma UGRP1 levels were associated with the G-112A UGRP1 gene promoter polymorphism and the severity of asthma.

Uteroglobin: a steroid-inducible immunomodulatory protein that founded the Secretoglobin superfamily

Blastokinin or uteroglobin (UG) is a steroid-inducible, evolutionarily conserved, secreted protein that has been extensively studied from the standpoint of its structure and molecular biology. However, the physiological function(s) of UG still remains elusive. Isolated from the uterus of rabbits during early pregnancy, UG is the founding member of a growing superfamily of proteins called Secretoglobin (Scgb). Numerous studies demonstrated that UG is a multifunctional protein with antiinflammatory/ immunomodulatory properties. It inhibits soluble phospholipase A(2) activity and binds and perhaps sequesters hydrophobic ligands such as progesterone, retinols, polychlorinated biphenyls, phospholipids, and prostaglandins. In addition to its antiinflammatory activities, UG manifests antichemotactic, antiallergic, antitumorigenic, and embryonic growth-stimulatory activities. The tissue-specific expression of the UG gene is regulated by several steroid hormones, although a nonsteroid hormone, prolactin, further augments its expression in the uterus. The mucosal epithelia of virtually all organs that communicate with the external environment express UG, and it is present in the blood, urine, and other body fluids. Although the physiological functions of this protein are still under investigation, a single nucleotide polymorphism in the UG gene appears to be associated with several inflammatory/autoimmune diseases. Investigations with UG-knockout mice revealed that the absence of this protein leads to phenotypes that suggest its critical homeostatic role(s) against oxidative damage, inflammation, autoimmunity, and cancer. Recent studies on UG-binding proteins (receptors) provide further insight into the multifunctional nature of this protein. Based on its antiinflammatory and antiallergic properties, UG is a potential drug target.

Cloning, characterization and expression analysis of pufferfish interleukin-4 cDNA: The first evidence of Th2-type cytokine in fish

Interleukin-4 (IL-4) is one of the key cytokines in Th2 mediated immune responses, which has been shown to regulate the responses of many immune cytokines, such as interferon-gamma (IFN-gamma), interleukin-1 (IL-1) and TNF-alpha. Much work on IL-4 has been done in human and several mammal species while little in fish. In this study, we have cloned and characterized the full-length cDNA of IL-4 in Tetraodon. The Tetraodon IL-4 cDNA is 834bp in length and contains a short 5'UTR of 39bp, a 3'UTR of 375bp and an open reading frame of 420bp translating into a protein of 139aa with a predicted molecular mass of 16.131kDa. The Tetraodon IL-4-encoding gene with the same organization as the mammalians and birds consists of four exons and three introns. The encoded protein shows 11-16% identities to other homologues. RT-PCR was optimized to estimate the expression level of IL-4 in Tetraodon. The results showed that IL-4 is constitutively expressed in all selected tissues, including head kidney, spleen, liver, brain, gill, muscle and heart, although low levels were observed in head kidney, spleen, and liver. The ubiquitous expression of IL-4 is consistent with a postulated role in immune cytokines regulation. Stimulating the fish with a mixed stimulant that contained 2 microg ConA, 2 microg PHA, and 2 microg PMA, significantly up-regulated the expression of IL-4 in most tissues examined, which potentially indicated that IL-4 was involved in the immune inflammatory responses triggered by mitogens. This is the first report of cloning and characterization of IL-4 cDNA and gene in fish.

Antenatal risk factors, cytokines and the development of atopic disease in early childhood

Atopic diseases are complex entities influenced by an array of risk factors, including genetic predisposition, environmental allergens, antenatal exposures, infections and psychosocial factors. One proposed mechanism by which these risk factors contribute to the development of atopic disease is through changes in the production of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) cytokines. The objectives of this review are to discuss antenatal exposures that are associated with paediatric atopic diseases, to discuss the influence of the intrauterine environment on neonatal immune responses, to provide an overview of the Th1 and Th2 pathways and how they relate to atopic disease, and to summarise our current understanding of the association between cytokine responses in cord blood and the development of atopic disease in early childhood.

Uteroglobin-Related Protein 1 and Clara Cell Protein in Induced Sputum of Patients With Asthma and Rhinitis

RATIONALE

Uteroglobin-related protein 1 (UGRP1) and Clara cell protein (CC16), members of the secretoglobin family, increasingly appear to play a role in airway inflammatory response.

OBJECTIVE

To explore levels of UGRP1 and CC16 in induced sputum of patients with asthma and rhinitis.

METHODS

Induced-sputum samples of patients with asthma or rhinitis (n = 32 each; atopic asthma, n = 24; atopic rhinitis, n = 20) and from 19 nonsmoking nonatopic control subjects were analyzed for cytology and levels of UGRP1, CC16, and albumin.

MEASUREMENTS AND MAIN RESULTS

Sputum UGRP1 increased in both asthma and rhinitis, most strikingly so in asthma, in which changes were most significant in atopic individuals. By contrast, sputum CC16 did not change significantly in either condition, although it was positively correlated with UGRP1 in patients and control subjects. Changes in sputum UGRP1 in atopic asthma were not linked to permeability changes reflected by increased albumin levels but correlated positively with sputum macrophages and negatively with eosinophils. The observed differences in UGRP1 and CC16 may be linked to different cell populations being responsible for their secretion; UGRP1 is mainly secreted in larger conducting airways, whereas CC16 is mainly secreted by the nasal and peripheral airways epithelium.

CONCLUSIONS

The increase in UGRP1 but not of CC16 in asthma and rhinitis suggests that UGRP1 may play a role in these inflammatory diseases.

Pharmacogenomics of beta2-agonist: key focus on signaling pathways

Asthma is one of the most common respiratory diseases, where inhalation and exhalation are obstructed due to narrowing of the airways by broncho-constriction or by inflammation. Among all the available anti-asthma therapies, beta2-agonists are the most effective bronchodilators available, and give rapid relief of asthma symptoms. Evidence suggests that the degree of beta2-agonist response varies greatly between patients and genetic factors have a major role in it. Despite several studies on the beta2-agonist pharmacogenetics, significant gaps in knowledge still remain and need to be resolved before the pharmacotyping of beta2-agonist responsiveness comes to clinical practice. As we know, beta2-agonists show their influence by targeting beta2-adrenergic receptors, leading to the activation of beta2-adrenergic receptors and its downstream cascade. Signaling through beta2-adrenergic receptors mediates numerous airway functions by regulating broncho-constriction and dilation pathways. Therefore, it is an important prerequisite to understand these pathways, which will assist in defining the variability in therapeutic responses for beta2-agonists. Owing to the complexity of the action of a beta2-agonist and its therapeutic response, a broader genomics approach will help in optimizing therapy for the individual patient. This might be achieved by considering and focusing on receptor/s at which the drug binds directly, signal transduction cascades or downstream proteins and proteins involved in the relaxation and constriction of the airway smooth muscle. Considering that a drug response may involve a large number of proteins, it seems unlikely that a single polymorphism or haplotype in a single gene would explain a high degree of drug response variability in a consistent fashion. Thus, it shows that a polygenic approach will be more appropriate. In order to follow this, the mode of action of the beta2-agonist and its downstream signaling cascade should essentially be assessed to resolve the beta2-agonist enigma.

Association of the RIP2 gene with childhood atopic asthma

BACKGROUND

Receptor-interacting protein (RIP)-2 is a serine/threonine kinase containing a caspase recruitment domain (CARD) that is involved in the Toll-like receptor-signaling pathway. Although associations between endotoxin exposure or respiratory infection and asthma have been recognized, the genetic influences in these conditions are unclear. The aim of our study was to examine whether polymorphisms or haplotypes in RIP2 were associated with childhood atopic asthma in a Japanese population.

METHODS

We screened the RIP2 gene for polymorphisms by direct sequencing and characterized the linkage disequilibrium (LD) mapping of the gene. Seven variants were genotyped in childhood atopic asthma (n = 300) and normal controls (n = 637) . We conducted case-control and case-only association studies between the variants and asthma-related phenotypes. Haplotype association analyses were also performed.

RESULTS

A total of 31 variants were identified and none of the alleles or haplotypes of RIP2 were associated with asthma susceptibility. In the case-only study, an association between an RIP2 promoter polymorphism and childhood severe asthma (P=0.0032; odds ratio (OR) 3.37, 95% confidence interval (CI) 1.45-7.87) was observed.

CONCLUSIONS

Although polymorphisms in RIP2 are not likely to be associated with the development of asthma, the genetic variants might contribute to asthma severity in the Japanese population.

Uteroglobin-related protein 1 expression suppresses allergic airway inflammation in mice

RATIONALE

Uteroglobin-related protein (UGRP) 1, which is highly expressed in the epithelial cells of the airways, has been suggested to play a role in lung inflammation.

OBJECTIVES

The aim of study was to understand the effect of overexpressed UGRP1 on lung inflammation in a mouse model of allergic airway inflammation.

METHODS

Ovalbumin-sensitized and -challenged mice, a model for allergic airway inflammation, were used in conjunction with recombinant adenovirus expressing UGRP1.

MEASUREMENTS AND MAIN RESULTS

We demonstrated that intranasal administration of adeno-UGRP1 successfully delivered UGRP1 to the epithelial cells of airways and markedly reduced the number of infiltrating inflammatory cells, particularly eosinophils, in lung tissue as well as the level of proinflammatory cytokines such as interleukin (IL)-4, IL-5, and IL-13 in bronchoalveolar lavage fluids. The healed phase of inflammation was clearly seen in the peripheral areas of adeno-UGRP1-treated mouse lungs.

CONCLUSION

These results demonstrate that UGRP1 can suppress inflammation in the mouse model of allergic airway inflammation. Based on this result, we propose UGRP1 as a novel therapeutic candidate for treating lung inflammation such as is found in asthma.

Association study between the IL4, IL13, IRF1 and UGRP1 genes in chromosomal 5q31 region and Chinese Graves' disease

Graves' disease (GD) was believed to be a polygenic disease. Several chromosomal regions were linked to GD, and the 5q31 chromosome regions containing several interleukin genes cluster were worth observing. In this study, IL4, IL13, IRF1 and UGRP1 genes were sequenced, and 5, 3, 7 and 7 polymorphisms respectively were discovered. Then an extended association study for the attracting polymorphisms was performed with 146 sporadic Graves' patients, 142 unrelated controls and the 54 multiplex Graves' families. However, the genotype and allele frequency distribution of these polymorphisms had similar distribution between the Graves' patients and unrelated controls, and transmission disequilibrium tests indicated that none of them showed dominant transmission from heterozygous parents to the affected offsprings. Comparison of the clinical variables of the Graves' patients indicated that the onset ages of the patients carrying TT at IRF1 6477 T/G locus were younger than those having variant allele (TG, GG); the difference was of statistical significance (P=0.005, Pc=0.020). Our association study revealed that, IL4, IL13, IRF1 and UGRP1 genes in chromosomal 5q31 regions might not confer susceptibility to Chinese GD. But those individuals who were TT homozygous at IRF1 6477 T/G locus seemed to be attacked by GD much earlier than others.

Interleukin-5 reduces the expression of uteroglobin-related protein (UGRP) 1 gene in allergic airway inflammation

Airway inflammation is thought to play a major role in the pathogenesis of bronchial asthma. The precise role of individual inflammatory cells, mediator and asthma related genes in allergic lung diseases is not completely understood. The uteroglobin-related protein (UGRP) 1 was proposed to be an asthma candidate gene and play a role in regulating lung inflammation, however its precise function in the airways remains obscure. In this investigation, we used a mouse model of allergic airway inflammation to establish a relationship between UGRP 1 and IL-5 in airway inflammation. Ovalbumin (OVA) challenged mice demonstrate eosinophilia in airway tissues and high levels of IL-5 in bronchoalveolar lavage (BAL) fluid analogous to that found in bronchial asthma. Interestingly, these "OVA-challenged" mice show down-regulation of Ugrp1 expression as compared with the control group. Regression analysis further demonstrates a significant negative correlation between Ugrp1 mRNA expression in the lung and IL-5 levels in BAL fluid with r = 0.948 and P < 0.0001 when IL-5 levels were normalized by log transformation. Intranasal instillation of IL-5 to mice revealed an inhibitory effect of IL-5 on the expression of Ugrp1 mRNA. Together, these results indicate an involvement of IL-5 in the down-regulation of Ugrp1 expression in airway inflammation such as allergic asthma disease.

Association of the hCLCA1 gene with childhood and adult asthma

Asthma is caused by bronchial inflammation. This inflammation involves mucus overproduction and hypersecretion. Recently, a mouse model of asthma showed that gob-5 is involved in the pathogenesis of asthma. The gob-5 gene is involved in mucus secretion and its expression is upregulated upon antigen attack in sensitized mice. The observation suggests that human homologue of gob-5, hCLCA1 (human calcium-dependent chloride channel-1), may be involved in human disease. We screened for single-nucleotide polymorphisms (SNPs) in hCLCA1 in the Japanese population. We identified eight SNPs, and performed association studies using 384 child patients with asthma, 480 adult patients with asthma, and 672 controls. In haplotype analysis, we found a different haplotype distribution pattern between controls and childhood asthma (P<0.0001) and between controls and adult asthma (P=0.0031). We identified a high-risk haplotype (CATCAAGT haplotype; P=0.0014) and a low-risk haplotype (TGCCAAGT haplotype; P=0.00010) in cases of childhood asthma. In diplotype analysis, patients who had the CATCAAGT haplotype showed a higher risk for childhood asthma than those who did not (P=0.0011). Individuals who had the TGCCAAGT haplotype showed a lower risk for childhood asthma than those who did not (P<0.0001). Our data suggested that variation of the hCLCA1 gene affects patients' susceptibility for asthma.

Variations in the C3, C3a receptor, and C5 genes affect susceptibility to bronchial asthma

Bronchial asthma (BA) is a common chronic inflammatory disease characterized by hyperresponsive airways, excess mucus production, eosinophil activation, and the production of IgE. The complement system plays an immunoregulatory role at the interface of innate and acquired immunities. Recent studies have provided evidence that C3, C3a receptor, and C5 are linked to airway hyperresponsiveness. To determine whether genetic variations in the genes of the complement system affect susceptibility to BA, we screened single nucleotide polymorphisms (SNPs) in C3, C5, the C3a receptor gene (C3AR1), and the C5a receptor gene (C5R1) and performed association studies in the Japanese population. The results of this SNP case-control study suggested an association between 4896C/T in the C3 gene and atopic childhood BA (P = 0.0078) as well as adult BA (P = 0.010). When patient data were stratified according to elevated total IgE levels, 4896C/T was more closely associated with adult BA (P = 0.0016). A patient-only association study suggested that severity of childhood BA was associated with 1526G/A of the C3AR1 gene (P = 0.0057). We identified a high-risk haplotype of the C3 gene for childhood (P = 0.0021) and adult BA (P = 0.0058) and a low-risk haplotype for adult BA (P = 0.00011). We also identified a haplotype of the C5 gene that was protective against childhood BA (P = 1.4 x 10(-6)) and adult BA (P = 0.00063). These results suggest that the C3 and C5 pathways of the complement system play important roles in the pathogenesis of BA and that polymorphisms of these genes affect susceptibility to BA.

Decreased expression of uteroglobin-related protein 1 in inflamed mouse airways is mediated by IL-9

Uteroglobin-related protein 1 (UGRP1) is a secretory protein, highly expressed in epithelial cells of airways. Although an involvement of UGRP1 in the pathogenesis of asthma has been suggested, its function in airways remains unclear. In the present study, a relationship between airway inflammation, UGRP1 expression, and interleukin-9 (IL-9), an asthma candidate gene, was evaluated by using a murine model of allergic bronchial asthma. A severe airway inflammation accompanied by airway eosinophilia and elevation of IL-9 in bronchoalveolar lavage (BAL) fluids was observed after ovalbumin (OVA) challenge to OVA-sensitized mice. In this animal model of airway inflammation, lung Ugrp1 mRNA expression was greatly decreased compared with control mice. A significant inverse correlation between lung Ugrp1 mRNA levels and IL-9 levels in BAL fluid was demonstrated by regression analysis (r = 0.616, P = 0.023). Immunohistochemical analysis revealed a distinct localization of UGRP1 in airway epithelial cells of control mice, whereas UGRP1 staining was patchy and faint in inflamed airways. Intranasal administration of IL-9 to naive mice decreased the level of Ugrp1 expression in lungs. These findings suggest that UGRP1 is downregulated in inflamed airways, such as allergic asthmatics, and IL-9 might be an important mediator for modulating UGRP1 expression.

Uteroglobin-related protein 1(UGRP1) gene polymorphisms and atopic asthma in the Indian population

BACKGROUND

The secretory protein, uteroglobin-related protein 1 (UGRP1), is mainly expressed in the lung and trachea and has recently been implicated in asthma. The -112 G to A transition in the promoter was reported to be associated with asthma in the Japanese population. However, this has not been replicated in other studies. The aim of this study was to find the association of UGRP1 gene polymorphisms with atopic asthma in the Indian population using a case-control (NP=165, NC=160) and a family-based (60 trios) design.

METHODS

Polymorphisms in the promoter region and the first exon and first intron of the UGRP1 gene were determined by direct sequencing.

RESULTS

The previously identified G-112A and C222A polymorphisms were found to be in complete linkage disequilibrium (LD) (D'=1) in our population. However, no new polymorphism has been identified in this region. When G-112A polymorphism was analyzed in the cases and controls, no significant difference was observed either at the allele (p=0.68) or at the genotype (p=0.83) levels. Moreover, in our family-based study, we observed no significant deviation of allelic transmission from random proportions (p=0.41). Similarly, when we analyzed our genotypic results for serum total IgE levels, no significant association was observed, in both case-control as well as family-based designs.

CONCLUSIONS

Our results suggest that the G-112A and C222A polymorphisms do not play a significant role in the genetic predisposition of UGRP1 gene in atopic asthma in the Indian population.

Interleukin-10 Induces Uteroglobin-related Protein (UGRP) 1 Gene Expression in Lung Epithelial Cells through Homeodomain Transcription Factor T/EBP/NKX2.1

UGRP1 is a downstream target gene for homeodomain transcription factor T/EBP/NKX2.1, which is predominantly expressed in lung epithelial cells, and may play an anti-inflammatory role in lung inflammation. To understand the role of UGRP1 in inflammation, its expression was investigated in relation to cytokine signaling. In vivo experiments using mouse embryonic lung organ culture and intranasal administration of interleukin (IL) 10 revealed that constitutive expression of Ugrp1 mRNA is enhanced by IL-10. Increase of protein levels was also demonstrated by immunohistochemistry using embryonic lungs. This IL-10 induction of Ugrp1 gene expression occurs at the transcriptional level when examined using mouse embryonic lung primary cultures. In human lung NCI-H441 cells that in contrast to mouse lung cells, do not exhibit constitutive expression of the gene, expression of the UGRP1 gene was induced in a rapid and stable fashion. Two T/EBP, but not STAT3, binding sites located in the human UGRP1 gene promoter are responsible for IL-10 induction of the UGRP1 gene as judged by transfection, gel shift, and chromatin immunoprecipitation analyses. The IL-10 receptor chains, IL-10R1 and IL-10R2, are expressed in H441 cells, however, STAT3 was only weakly activated upon IL-10 treatment. In contrast, STAT3 was strongly activated when the cells were treated with other cytokines such as IL-22 and interferon-beta but UGRP1 expression was not increased. Together these results demonstrate that IL-10 induces UGRP1 gene expression in lung epithelial cells through a T/EBP/NKX2.1-dependent pathway. The results further suggest that UGRP1 might be a target for IL-10 anti-inflammatory activities in the lung.

Inflammation in allergic asthma: initiating events, immunological response and risk factors

Allergic asthma affects 155 million people worldwide. Currently, it is a disease that can be controlled by diverse therapeutic approaches but that cannot be cured. This means that asthma is one of the most expensive diseases for healthcare systems in developed countries. Efficient prevention strategies are therefore greatly needed to reduce both individual morbidity and national economic burdens. This requires a detailed knowledge of the immunological and physiological mechanisms involved in asthma. This review synthesizes current understanding about the immunobiology of IgE-mediated asthma. It discusses the initiating events, the main immunological and inflammatory processes, and addresses the importance of risk factors in the development and maintenance of allergic diseases. Finally, it integrates these concepts in a theoretical causal model for atopic asthma.

The mouse salivary androgen-binding protein (ABP) gene cluster on chromosomes 7: characterization and evolutionary relationships

Mouse salivary androgen-binding protein (ABP) is a pair of dimers, composed of an alpha subunit disulfide bridged to either a beta or a gamma subunit. It has been proposed that each subunit is encoded by a distinct gene: Abpa, Abpb, and Abpg for the alpha, beta, and gamma subunits, respectively. We report here the structures and sequences of the genes that encode these three subunits. Each gene has three exons separated by two introns. Mouse salivary ABP is a member of the secretoglobin family, and we compare the structure of the three ABP subunit genes to those of 18 other mammalian secretoglobins. We map the three genes as a gene cluster located 10 cM from the centromere of Chromosome (Chr) 7 and show that Abpa is the closest of the three to the gene for glucose phosphate isomerase (GPI) and that Abpg is the closest to the centromere, with Abpb mapping between them. Abpa is oriented in the opposite direction to Abpb and Abpg, with its 5' end directed toward their 5' ends. We compare the location of these genes with other secretoglobin genes in the mouse genome and with the known locations of secretoglobin genes in the human genome and present evidence that strong positive selection has driven the divergence of the coding regions of Abpb and Abpg since the putative duplication event that created them.

Recent development in genomic and proteomic research for asthma

PURPOSE OF REVIEW

Asthma is a complex genetic disorder with a heterogeneous phenotype attributed to the interactions among many genes and the environment. This review highlights recent developments in asthma genomic and proteomic research.

RECENT FINDINGS

Numerous loci and candidate genes have been reported to show linkage and association of asthma and the asthma-associated phenotypes, atopy, elevated immunoglobulin E (IgE) levels, and bronchial hyperresponsiveness to alleles of microsatellite markers and single nucleotide polymorphisms within specific cytokine/chemokine, and IgE regulating genes. Although many studies reporting these observations are compelling, only a few genes conferring significant risk have been mapped. Although significant progress has been made in the field of asthma genetics in the past decade, the clinical implications of the genetic variations within the numerous candidate asthma genes, which have been found to associate with the expression of the asthmatic phenotype, remain largely undetermined. However, in the past year the scientific community has benefited from postgenomic discoveries, with the recent cloning of two asthma genes, ADAM 33 and PHF11, and this has generated new information that is benefiting others.

SUMMARY

The asthma genetics field has advanced considerably in recent years, with new information being generated that has led to improved understanding of the pathobiology underlying this complex disorder. This has also generated interest in the study of gene-gene interaction and how linkage disequilibrium blocks and haplotypes can be used as functional units to pinpoint mutations and capture relative risk of mutated genes in complex disorders.

Association studies for asthma and atopic diseases: a comprehensive review of the literature

Hundreds of genetic association studies on asthma-related phenotypes have been conducted in different populations. To date, variants in 64 genes have been reported to be associated with asthma or related traits in at least one study. Of these, 33 associations were replicated in a second study, 9 associations were not replicated either in a second study or a second sample in the same study, and 22 associations were reported in just a single published study. These results suggest the potential for a great amount of heterogeneity underlying asthma. However, many of these studies are methodologically limited and their interpretation hampered by small sample sizes.

Polymorphisms in the 5'-untranslated region of the human serotonin receptor 1B (HTR1B) gene affect gene expression

We present evidence of complex balancing regulation of HTR1B transcription by common polymorphisms in its promoter. Computational analysis of the HTR1B gene predicted that a 5' segment, spanning common DNA sequence variations, T-261G, A-161T, and -182INS/DEL-181, contained a putative functional promoter. Using a secreted alkaline phosphatase (SEAP) reporter gene system, we found that the haplotype -261G_-182INS-181_A-161 enhanced transcriptional activity 2.3-fold compared with the haplotype T-261_-182INS-181_A-161. Conversely, -161T reversed this, and the net effect when -261G and -161T were in the same haplotype (-261G_-182INS-181_-161T) was equivalent to the major haplotype (T-261_-182INS-181_A-161). Electrophoretic mobility shift experiments showed that -261G and -161T modify the binding of transcription factors (TFs): -261G generates a new AP2 binding site, while alleles A-161 and -161T exhibit different binding characteristics to AP1. T-261G and A-161T were found to be in linkage disequilibrium (LD) with G861C in a European ancestry population. Interestingly, G861C has been reported to be associated with several psychiatric disorders. Our results indicate that HTR1B is the target of substantial transcriptional genetic regulation by common haplotypes, which are in LD with the HTR1B single-nucleotide polymorphism (SNP) most commonly used in association studies.

Association of uteroglobulin-related protein 1 with bronchial asthma

BACKGROUND

Chromosomal region 5q31 harbours a number of genes associated with atopic phenotypes, for example the genes coding for interleukin (IL) 4, IL13 and the beta(2)-adrenoreceptor. A new gene within this region was identified only very recently. The encoded protein - uteroglobin-related protein 1 (UGRP1) - is thought to act as an anti-inflammatory agent and is mainly expressed in the lung and trachea. The functional promoter polymorphism A-112G in UGRP1 was shown to be associated with bronchial asthma in a Japanese population. We were thus interested in finding out whether the polymorphism so far identified or others within UGRP1 were associated with bronchial asthma in a German Caucasian population.

METHODS

We performed direct genomic sequencing of the promoter and coding region of UGRP1 in 15 asthmatic children and 15 controls. The identified polymorphisms were genotyped by means of RFLP. Statistical analysis was performed with the Armitage trend test.

RESULTS

We identified 5 non-coding variants, 4 of which being described for the first time. Three polymorphisms were common and typed in 182 asthmatic children and 270 controls. None of the polymorphisms were associated with bronchial asthma in our population.

CONCLUSIONS

We conclude from our data that UGRP1 does not play a major role in the development of bronchial asthma in our Caucasian population.

Genetic variants of the IL13 and IL4 genes and atopic diseases in at-risk children

We studied a cohort containing 368 children at high risk of developing atopy and atopic disorders and 540 parents of those children to investigate whether the IL13 Arg130Gln and C-1112 T polymorphisms were associated with these outcomes. We also investigated whether haplotypes consisting of any two polymorphisms of IL13 Arg130Gln, IL13 C-1112 T and IL4 C-589 T were associated with these phenotypes. In 288 white children, the IL13 130Gln allele was associated with atopy (RR=1.9, P=0.047), and with atopic dermatitis (RR=2.5, P=0.014). The associations were confirmed using a family-based test of association (P=0.027 and 0.030, respectively) in all subjects. In white subjects there were associations of haplotypes consisting of IL13 Arg130Gln and IL4 C-589 T with atopic dermatitis (P=0.006) and with atopy (P=0.009). Our data suggest that the IL13 Arg130Gln polymorphism and haplotypes consisting of IL13 Arg130Gln and IL4 C-589 T were associated with the development of atopy and atopic dermatitis at 24 months of age.

No evidence for association between the -112G/A polymorphism of UGRP1 and childhood atopic asthma

BACKGROUND

Susceptibility to asthma is known to involve genetic factors. Genome-wide screens have indicated that the chromosome 5q31-q34 region is linked to and/or associated with asthma. A new gene, named UGRP1 and reported by Niimi et al., encodes uteroglobin-related protein and is expressed in the lung and trachea. Niimi et al. showed the -112G/A polymorphism of the UGRP1 gene to be associated with asthma in a case-control study.

OBJECTIVE

The objective of the present study was to replicate this association and confirm the possible role of the UGRP1-112G/A polymorphism in the aetiology of childhood asthma in a Japanese population.

METHODS AND RESULTS

We conducted a transmission disequilibrium test (TDT) in 131 families identified through paediatric patients being treated for asthma. A case-control study was also carried out by comparing the probands and 137 unrelated non-atopic non-asthmatic Japanese children and 211 unrelated healthy Japanese adults. The -112G/A polymorphism was genotyped by the PCR-RFLP method. The TDT revealed that the -112A allele was not preferentially transmitted to asthma-affected children (P=0.85). Neither the presence of at least one A allele in an individual's genotype (sum of the G/A and A/A genotypes) nor the -112A allele was more prevalent among the asthma subjects than among the control subjects.

CONCLUSION

Our findings indicate that the UGRP1-112G/A polymorphism does not play a substantial role in genetic predisposition to childhood asthma in this Japanese population.

Secretoglobins SCGB3A1 and SCGB3A2 define secretory cell subsets in mouse and human airways

Clara cell secretory protein (CCSP) is expressed abundantly within the conducting airway epithelium and is thought to have immunoregulatory functions. Differences in the localization of CCSP between mouse and human airways led us to hypothesize that functional homologues of CCSP may compensate for the lack of CCSP expression in proximal airway locations. We previously identified an expressed sequence tag (W82219) whose expression is induced within Clara cells of CCSP knockout mice. Expressed sequence tag W82219 is distantly related to CCSP and represents a member of a new subfamily of secretoglobins (MmSCGB3A2). Another member of the mouse SCGB3 family (MmSCGB3A1) as well as human orthologues (HsSCGB3A1 and HsSCGB3A2) that possess structural homology to CCSP were identified, suggesting they may share common functional properties. SCGB3A1 messenger RNA localizes to a subset of SCGB3A2-expressing cells within bronchi of both mouse and neonatal human lungs. CCSP, SCGB3A1, and SCGB3A2 were decreased in airways of neonates with bronchopulmonary dysplasia and in mice after airway injury. We conclude that secretory cells of the conducting airway epithelium express distinct members of the secretoglobin family in a partially overlapping fashion. Altered expression of secretoglobins in airway disease may contribute to immunoregulatory perturbations commonly seen in chronic airway disease.