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Amplifluor-Based SNP Genotyping. Methods Mol Biol 2023; 2638:191-200. [PMID: 36781643 DOI: 10.1007/978-1-0716-3024-2_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Amplifluor, a genotyping system used to analyze single nucleotide polymorphisms (SNPs), is supplied by Merck-Millipore. Amplifluor is based on polymerase chain reaction (PCR) with two competing allele-specific primers and a SNP specific common reverse primer. Sequence information flanking SNP of interest and fluorescent plate reader for end-point measurement or qPCR machine for real time measurement are required for the execution of the Amplifluor assay. In this chapter, the principle and working protocol of the Amplifluor assay based on end-point fluorescence detection of SNP allele is presented with an example.
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Zhao Y, Zhang X, Han C, Cai Y, Li S, Hu X, Wu C, Guan X, Lu C, Nie X. Pharmacogenomics of Leukotriene Modifiers: A Systematic Review and Meta-Analysis. J Pers Med 2022; 12:jpm12071068. [PMID: 35887565 PMCID: PMC9316609 DOI: 10.3390/jpm12071068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 11/16/2022] Open
Abstract
Pharmacogenetics research on leukotriene modifiers (LTMs) for asthma has been developing rapidly, although pharmacogenetic testing for LTMs is not yet used in clinical practice. We performed a systematic review and meta-analysis on the impact of pharmacogenomics on LTMs response. Studies published until May 2022 were searched using PubMed, EMBASE, and Cochrane databases. Pharmacogenomics/genetics studies of patients with asthma using LTMs with or without other anti-asthmatic drugs were included. Statistical tests of the meta-analysis were performed with Review Manager (Revman, version 5.4, The Cochrane Collaboration, Copenhagen, Denmark) and R language and environment for statistical computing (version 4.1.0 for Windows, R Core Team, Vienna, Austria) software. In total, 31 studies with 8084 participants were included in the systematic review and five studies were also used to perform the meta-analysis. Two included studies were genome-wide association studies (GWAS), which showed different results. Furthermore, none of the SNPs investigated in candidate gene studies were identified in GWAS. In candidate gene studies, the most widely studied SNPs were ALOX5 (tandem repeats of the Sp1-binding domain and rs2115819), LTC4S-444A/C (rs730012), and SLCO2B1 (rs12422149), with relatively inconsistent conclusions. LTC4S-444A/C polymorphism did not show a significant effect in our meta-analysis (AA vs. AC (or AC + CC): −0.06, 95%CI: −0.16 to 0.05, p = 0.31). AA homozygotes had smaller improvements in parameters pertaining to lung functions (−0.14, 95%CI: −0.23 to −0.05, p = 0.002) in a subgroup of patients with non-selective CysLT receptor antagonists and patients without inhaled corticosteroids (ICS) (−0.11, 95%CI: −0.14 to −0.08, p < 0.00001), but not in other subgroups. Variability exists in the pharmacogenomics of LTMs treatment response. Our meta-analysis and systematic review found that LTC4S-444A/C may influence the treatment response of patients taking non-selective CysLT receptor antagonists for asthma, and patients taking LTMs not in combination with ICS for asthma. Future studies are needed to validate the pharmacogenomic influence on LTMs response.
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Affiliation(s)
- Yuxuan Zhao
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Xinyi Zhang
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Congxiao Han
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Yuchun Cai
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Sicong Li
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Xiaowen Hu
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Caiying Wu
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Xiaodong Guan
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
| | - Christine Lu
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA 02115, USA;
| | - Xiaoyan Nie
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; (Y.Z.); (X.Z.); (C.H.); (Y.C.); (S.L.); (X.H.); (C.W.); (X.G.)
- Correspondence:
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Cornejo-García JA, Perkins JR, Jurado-Escobar R, García-Martín E, Agúndez JA, Viguera E, Pérez-Sánchez N, Blanca-López N. Pharmacogenomics of Prostaglandin and Leukotriene Receptors. Front Pharmacol 2016; 7:316. [PMID: 27708579 PMCID: PMC5030812 DOI: 10.3389/fphar.2016.00316] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/02/2016] [Indexed: 01/15/2023] Open
Abstract
Individual genetic background together with environmental effects are thought to be behind many human complex diseases. A number of genetic variants, mainly single nucleotide polymorphisms (SNPs), have been shown to be associated with various pathological and inflammatory conditions, representing potential therapeutic targets. Prostaglandins (PTGs) and leukotrienes (LTs) are eicosanoids derived from arachidonic acid and related polyunsaturated fatty acids that participate in both normal homeostasis and inflammatory conditions. These bioactive lipid mediators are synthesized through two major multistep enzymatic pathways: PTGs by cyclooxygenase and LTs by 5-lipoxygenase. The main physiological effects of PTGs include vasodilation and vascular leakage (PTGE2); mast cell maturation, eosinophil recruitment, and allergic responses (PTGD2); vascular and respiratory smooth muscle contraction (PTGF2), and inhibition of platelet aggregation (PTGI2). LTB4 is mainly involved in neutrophil recruitment, vascular leakage, and epithelial barrier function, whereas cysteinyl LTs (CysLTs) (LTC4, LTD4, and LTE4) induce bronchoconstriction and neutrophil extravasation, and also participate in vascular leakage. PTGs and LTs exert their biological functions by binding to cognate receptors, which belong to the seven transmembrane, G protein-coupled receptor superfamily. SNPs in genes encoding these receptors may influence their functionality and have a role in disease susceptibility and drug treatment response. In this review we summarize SNPs in PTGs and LTs receptors and their relevance in human diseases. We also provide information on gene expression. Finally, we speculate on future directions for this topic.
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Affiliation(s)
- José A Cornejo-García
- Research Laboratory, International Business Information Management Association (IBIMA)-Regional University Hospital of Malaga, University of Málaga (UMA)Malaga, Spain; Allergy Unit, International Business Information Management Association (IBIMA)-Regional University Hospital of Malaga, University of Málaga (UMA)Malaga, Spain
| | - James R Perkins
- Research Laboratory, International Business Information Management Association (IBIMA)-Regional University Hospital of Malaga, University of Málaga (UMA) Malaga, Spain
| | - Raquel Jurado-Escobar
- Research Laboratory, International Business Information Management Association (IBIMA)-Regional University Hospital of Malaga, University of Málaga (UMA) Malaga, Spain
| | | | - José A Agúndez
- Department of Pharmacology, University of Extremadura Caceres, Spain
| | - Enrique Viguera
- Genetics Unit, Department of Cell Biology, Genetics and Physiology, Faculty of Sciences, University of Málaga Malaga, Spain
| | - Natalia Pérez-Sánchez
- Allergy Unit, International Business Information Management Association (IBIMA)-Regional University Hospital of Malaga, University of Málaga (UMA) Malaga, Spain
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Tanimoto J, Fujino H, Takahashi H, Murayama T. Human EP2 prostanoid receptors exhibit more constraints to mutations than human DP prostanoid receptors. FEBS Lett 2015; 589:766-72. [DOI: 10.1016/j.febslet.2015.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/03/2015] [Accepted: 02/04/2015] [Indexed: 01/25/2023]
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Abstract
The aim of this study was to explore whether prostaglandin D2 receptor (PTGDR) polymorphisms confer susceptibility to asthma. A meta-analysis was conducted on the associations between the PTGDR -549 C/T, -441 C/T, and -197 C/T polymorphisms and asthma using: (1) allele contrast, (2) the recessive model, (3) the dominant model, and (4) the additive model. Three polymorphism haplotypes were constructed in the order -549/-441/-179. Meta-analysis was performed on the haplotype CCC (high transcriptional activity) and of TCT (low transcriptional activity). A total of 13 separate comparative studies in 9 articles involving 7,155 patients with asthma and 7,285 control subjects were included in this meta-analysis. An association between asthma and the PTGDR -549 C/T polymorphism was found by allele contrast (OR = 1.133, 95 % CI = 1.004-1.279, P = 0.043). Ethnicity-specific meta-analysis showed an association between asthma and the PTGDR -549 C allele in Europeans (OR = 1.192, 95 % CI = 1.032-1.377, P = 0.017). Furthermore, stratifying subjects by age indicated an association between the PTGDR -549 C allele and asthma in adults (OR = 1.248, 95 % CI = 1.076-1.447, P = 0.003), but no association in children (OR = 0.933, 95 % CI = 0.756-1.154, P = 0.324). Analyses using the dominant and additive models showed the similar pattern as that observed for the PTGDR -549 C allele, that is, a significant association in Europeans and adults, but not in children. No association was found between asthma and the PTGDR -441 C/T or -197 C/T polymorphisms, and meta-analysis stratified by ethnicity and age also revealed no association between asthma and these polymorphisms. Furthermore, no association was found between asthma and the CCC and TCT haplotypes of PTGDR, and meta-analysis stratified by ethnicity and age revealed no association between asthma and the CCC and TCT PTGDR haplotypes. This meta-analysis demonstrates that the PTGDR -549 C/T polymorphism confers susceptibility to asthma in Europeans and adults. However, no association was found between the PTGDR 441 C/T and -197 C/T polymorphisms or the CCC and TCT haplotypes and asthma susceptibility.
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Abstract
A genetic contribution to develop chronic obstructive pulmonary disease (COPD) is well established. However, the specific genes responsible for enhanced risk or host differences in susceptibility to smoke exposure remain poorly understood. The goal of this review is to provide a comprehensive literature overview on the genetics of COPD, highlight the most promising findings during the last few years, and ultimately provide an updated COPD gene list. Candidate gene studies on COPD and related phenotypes indexed in PubMed before January 5, 2012 are tabulated. An exhaustive list of publications for any given gene was looked for. This well-documented COPD candidate-gene list is expected to serve many purposes for future replication studies and meta-analyses as well as for reanalyzing collected genomic data in the field. In addition, this review summarizes recent genetic loci identified by genome-wide association studies on COPD, lung function, and related complications. Assembling resources, integrative genomic approaches, and large sample sizes of well-phenotyped subjects is part of the path forward to elucidate the genetic basis of this debilitating disease.
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Affiliation(s)
- Yohan Bossé
- Centre de recherche Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, Canada.
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Isidoro-García M, Sanz C, García-Solaesa V, Pascual M, Pescador DB, Lorente F, Dávila I. PTGDR gene in asthma: a functional, genetic, and epigenetic study. Allergy 2011; 66:1553-62. [PMID: 21883277 DOI: 10.1111/j.1398-9995.2011.02685.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Asthma affects more than 300 million individuals in the world. Several studies have demonstrated the importance of the genetic component. The aim of this study is to develop a holistic approach, including genetic, epigenetic, and expression analysis to study the Prostaglandin D2 receptor gene (PTGDR) in asthmatic patients. METHODS In this study, 637 Caucasian individuals were included. Genetic variants were characterized by sequencing, and haplotype and diplotype combinations were established. Electrophoretic mobility shift assays (EMSAs) were performed with different promoter variants. An epigenetic analysis of PTGDR was for the first time developed by MassArray assays, and gene expression was determined by real-time polymerase chain reaction. RESULTS The -197T > C (Fisher's P = 0.028) and -613C > T (Fisher's P < 0.001) polymorphisms were found to be significantly associated with allergic asthma and allergy to pollen and mites, respectively. In addition, several haplotype and diplotype combinations were associated with different allergy and asthma phenotypes. The presence of the -613C > T SNP determined variations in the EMSAs. Moreover, consistent differences in the methylation and expression patterns were observed between asthmatic patients and controls determining a 2.34-fold increase of PTGDR gene expression in asthmatic patients. CONCLUSIONS Genetic combinations described have functional implications in the PTGDR promoter activity by changing the transcription factors affinity that will help characterize different risk groups. The differences observed in the transcription factors affinity and in the methylation pattern bring insight into different transcription regulation in these patients. To the best of our knowledge, this is the first work in which the implication of genetic and epigenetic factors of PTGDR has been characterized pointing to putative therapeutic targets.
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Affiliation(s)
- M Isidoro-García
- Department of Clinical Biochemistry, University Hospital of Salamanca, Spain.
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Jamrozik EF, Warrington N, McClenaghan J, Hui J, Musk AW, James A, Beilby JP, Hansen J, DE Klerk NH, Palmer LJ. Functional haplotypes in the PTGDR gene fail to associate with asthma in two Australian populations. Respirology 2011; 16:359-66. [PMID: 21199159 DOI: 10.1111/j.1440-1843.2010.01917.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND AND OBJECTIVE Haplotypes in the promoter region of the prostanoid DP receptor (PTGDR) gene have been shown to functionally influence gene transcription and to be associated with asthma in two previous case-control studies in Caucasians. This study tested the association of PTGDR haplotypes with asthma phenotypes in two large Caucasian-Australian populations. These results were incorporated in a meta-analysis with previously published data to determine the overall role for these haplotypes in the risk of asthma. METHODS Three PTGDR promoter-region single nucleotide polymorphisms (SNP) were genotyped in 368 individuals from the Western Australian Twin Child Health study and 2988 individuals from the Busselton Health Study. Logistic regression and transition disequilibrium tests were used to assess whether SNP genotypes and three SNP haplotypes were associated with doctor-diagnosed asthma or intermediate quantitative traits. Longitudinal data from the Busselton Health Study were used to examine whether PTGDR influences changes in lung function over time. Meta-analysis incorporated the findings of this study with those of two previous studies in Caucasian populations. RESULTS Cross-sectional associations between PTGDR haplotypes and asthma phenotypes were non-significant (P > 0.05) in both populations. Longitudinal analyses of PTGDR and lung function were also non-significant. Meta-analysis, however, suggested that haplotype TCT was significantly associated with decreased risk of asthma (OR = 0.76; P = 0.02) while haplotype CCC was not significantly associated with asthma (OR = 1.30; P = 0.07). CONCLUSIONS These results suggest that despite the non-significant findings in the present study populations, PTGDR promoter haplotypes may account for a small but significant proportion of the risk of asthma in Caucasian populations.
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Affiliation(s)
- Euzebiusz F Jamrozik
- Centre for Genetic Epidemiology and Biostatistics, University of Western Australia, West Perth, Western Australia, Australia.
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Kang MJ, Kwon JW, Kim BJ, Yu J, Choi WA, Shin YJ, Hong SJ. Polymorphisms of the PTGDR and LTC4S influence responsiveness to leukotriene receptor antagonists in Korean children with asthma. J Hum Genet 2011; 56:284-9. [PMID: 21307858 DOI: 10.1038/jhg.2011.3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Activation of the prostaglandin D2 receptor (PTGDR) may contribute to pulmonary vasodilation, bronchoconstriction, recruitment of eosinophils, basophils and T-lymphocytes, and enhanced synthesis of leukotriene C4. We investigated whether polymorphisms of the leukotriene C4 synthase (LTC4S) -444A/C and PTGDR -441T/C were associated with clinical phenotypes and responsiveness to leukotriene receptor antagonist (LTRA) in Korean asthmatic children. We enrolled 270 normal and 870 asthmatic children. We prescribed montelukast (5 mg per day) to 100 of asthmatic children, and analyzed the responsiveness to LTRA by exercise challenge tests. Polymorphisms were genotyped by PCR-restriction fragment length polymorphism. As the number of minor alleles of the PTGDR -441T/C and LTC4S -444A/C polymorphisms increased, the log total eosinophil counts increased in atopic asthmatic children (P-value=0.03). We found a significant association between responsiveness to montelukast and the PTGDR polymorphism (P-value=0.038). However, the LTC4S -444A/C and PTGDR -441T/C were not associated with the susceptibility for asthma (LTC4S, AA versus AC+CC, adjusted odds ratio of 0.98 (95% confidence interval, 0.73-1.31); PTGDR, TT versus TC+CC, adjusted odds ratio of 0.90 (95% confidence interval, 0.68-1.19)) or clinical phenotypes (P-value>0.05). The effects of the PTGDR and LTC4S polymorphisms on the enhancement of eosinophil counts were additive in the Korean children with asthma. In addition, the PTGDR polymorphism seems to be associated with the responsiveness to LTRA. Therefore, therapies that target the PTGDR may be useful for modulating the responsiveness to LTRA.
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Affiliation(s)
- Mi-Jin Kang
- Asan Institute for Life Sciences, University of Ulsan, Seoul, Korea
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Abstract
Advances have been made in defining the mechanisms for the control of allergic airway inflammation in response to inhaled antigens. Several genes, including ADAM33, DPP10, PHF11, GPRA, TIM-1, PDE4D, OPN3, and ORMDL3, have been implicated in the pathogenesis and susceptibility to atopy and asthma. Growing evidence associates asthma with a systemic propensity for allergic T-helper type 2 cytokines. Disordered coagulation and fibrinolysis also exacerbate asthma symptoms. Balance among functionally distinct dendritic cell subsets contributes to the outcome of T-cell-mediated immunity. Allergen-specific T-regulatory cells play a pivotal role in the development of tolerance to allergens and immune suppression. The major emphasis on immunotherapy for asthma during the past decade has been to direct the immune response to a type 1 response, or immune tolerance. In this review, we discuss the current information on the pathogenesis of allergic airway inflammation and potential immunotherapy, which could be beneficial in the treatment of airway inflammation, allergy, and asthma.
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Affiliation(s)
- Devendra K Agrawal
- Center for Clinical and Translational Science, Creighton University School of Medicine, CRISS II, Room 510, Omaha, NE 68178, USA.
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Prostanoid DP receptor (PTGDR) variants in mothers with post-coital associated preterm births: preliminary observations. J Perinatol 2010; 30:33-7. [PMID: 19710676 DOI: 10.1038/jp.2009.127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To describe prostanoid DP receptor (PTGDR) variants in women with preterm births who admitted to coital activity (CA) within 24 h of labor. STUDY DESIGN To achieve >80% statistical power, a pilot case-control study compared 24 premature births from mothers with CA (Group 1), 30 mothers of premature infants who did not have CA (Group 2 non-coital activity) and 95 non-coital activity mothers with term births (Group 3 controls). Four functional PTDGR single nucleotide polymorphisms (SNPs) were evaluated: T-549C, C-441/T, T-197C and G+1044A. PHASE 2.0.2 and SAS 9.2 were used for analysis. RESULT All SNPs were in Hardy-Weinberg equilibrium in controls. The C-441/T genotype frequency was significantly increased among Group 1 women relative to Group 2 and 3 women (odds ratio (OR): 30.1, 95% confidence interval (CI) 6.9-191 and 25.7 95%CI 25.7-not computible, respectively). Of the possible haplotypes among the groups, the TCTG haplotype (T-549C, C-441/T, T-197C and G+1044A) was significantly more frequent in Group 1 women compared with the control groups (OR 53.4, 95%CI 10.3-554.8). CONCLUSIONS A differential genomic pattern of PTGDR polymorphisms was identified in a sub-set of mothers which was associated with an increased risk of post-coital preterm birth.
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Philip G, van Adelsberg J, Loeys T, Liu N, Wong P, Lai E, Dass SB, Reiss TF. Clinical studies of the DP1 antagonist laropiprant in asthma and allergic rhinitis. J Allergy Clin Immunol 2009; 124:942-8.e1-9. [PMID: 19748656 DOI: 10.1016/j.jaci.2009.07.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 06/15/2009] [Accepted: 07/07/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Prostaglandin D(2) is a proinflammatory mediator believed to be important in asthma and allergic rhinitis (AR). Allelic variants in the prostaglandin D(2) receptor type 1 (DP1) gene (PTGDR) have been suggested to be associated with asthma susceptibility. OBJECTIVES We sought to investigate the efficacy of the DP1 antagonist laropiprant (alone or with montelukast) in asthma and seasonal AR and explore whether sequence variations in PTGDR are associated with asthma severity. METHODS For asthma, in a double-blind crossover study, 100 patients with persistent asthma were randomized to placebo or laropiprant, 300 mg/d for 3 weeks, followed by addition of montelukast, 10 mg/d for 2 weeks. PTGDR promoter haplotypes were categorized as high, medium, or low transcriptional efficiency. The primary efficacy end point was FEV(1). For AR, in a double-blind parallel-group study, 767 patients sensitized to a regionally prevalent fall allergen with symptomatic fall rhinitis were allocated to laropiprant, 25 mg/d or 100 mg/d; cetirizine, 10mg/d; or placebo for 2 weeks. The primary end point was the Daytime Nasal Symptoms Score. RESULTS For asthma, no significant differences in FEV(1) or asthma symptoms were noted for laropiprant versus placebo or laropiprant plus montelukast vs montelukast (differences between montelukast and placebo: P <or= .001). No clear association was seen between haplotype pair (ie, diplotype) and asthma severity. For AR, although cetirizine (vs placebo) demonstrated an improvement in the Daytime Nasal Symptoms Score (P < .001), laropiprant did not. CONCLUSION Laropiprant did not demonstrate efficacy in asthmatic patients or patients with AR. Variations in PTGDR did not appear related to baseline asthma severity or treatment response (NCT00533208; NCT00783601).
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Leung TF, Li CY, Kong APS, Chan IHS, Ng MCY, Chan MHM, So WY, Wong GWK, Lam CWK, Chan JCN. PTGDR is not a major candidate gene for asthma and atopy in Chinese children. Pediatr Allergy Immunol 2009; 20:556-62. [PMID: 19220773 DOI: 10.1111/j.1399-3038.2008.00835.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Airway sensitization requires the expression of prostanoid DP receptor in mice. Recent studies reported that polymorphisms in the gene encoding prostanoid DP receptor (PTGDR) were associated with asthma in White people and Black people, but this association could not be replicated among Latinos and Koreans. This study investigated the association between asthma-related traits and six single nucleotide polymorphisms (SNPs) of PTGDR in Chinese children, consisted of 308 asthmatics and 368 non-allergic controls. Plasma total and aeroallergen-specific immunoglobulin E were measured by immunoassays. PTGDR SNPs were determined by multiplex SNaPshot genotyping. All polymorphic markers followed Hardy-Weinberg equilibrium except G1044A in the controls (p = 0.021). The linkage disequilibrium (LD) scores for these SNPs were moderate to high, and in particular, T-549C and C-441T were in strong LD. Significant interethnic variations in PTGDR alleles and haplotypes (up to 41%) were found in our subjects when compared with White people or Latinos. Asthma diagnosis, atopy and aeroallergen sensitization did not differ among children with different PTGDR genotypes (p > 0.15 for all). Linear regression showed weakly significant associations between T-197C and G1044A of PTGDR and spirometric variables. PTGDR haplotypes were not associated with asthma and atopy phenotypes (p > 0.09 for all). Our results do not support PTGDR to be a major candidate gene for asthma traits in Chinese children.
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Affiliation(s)
- Ting Fan Leung
- Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
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Sanz C, Isidoro-García M, Dávila I, de Pedro MP, Méndez SDA, Padrón J, Ruiz-SanFrancisco A, Lorente F. A new PTGDR promoter polymorphism in a population of children with asthma. Pediatr Allergy Immunol 2009; 20:151-6. [PMID: 18811623 DOI: 10.1111/j.1399-3038.2008.00772.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Recently, functional genetic variants of the PTGDR gene have been associated with asthma. The objective of this work was to study polymorphisms of the promoter region of PTGDR and their haplotype and diplotype combinations in a Spanish population of children with asthma. In this study, 200 Caucasian individuals were included. Asthma was specialist-physician diagnosed according to the ATS criteria. The polymorphisms were analyzed by direct sequencing. In the study, the new polymorphism (-613C > T) in the promoter region of PTGDR was analyzed. The CT genotype was more common in controls (17%) than in patients with asthma (1%) (p-value = 0.0003; OR, 0.057; 95% CI, 0.007-0.441). The CCCT CCCC diplotype (promoter positions -613, -549, -441, and -197) was more frequent in the group of patients with asthma [Fisher's p-value = 0.012; OR, 10.24; 95% CI (1.25-83.68)]; this diplotype is unambiguous. To our knowledge, this is the first study of -613C > T PTGDR polymorphism in patients. This analysis provides more complete information on influence of diplotype combinations of PTGDR polymorphisms in asthma.
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Affiliation(s)
- Catalina Sanz
- Department of Allergy, University of Salamanca, Salamanca, Spain
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Oguma T, Asano K, Ishizaka A. Role of prostaglandin D(2) and its receptors in the pathophysiology of asthma. Allergol Int 2008; 57:307-12. [PMID: 18946232 DOI: 10.2332/allergolint.08-rai-0033] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Indexed: 12/31/2022] Open
Abstract
Prostaglandin D(2) (PGD(2)) is one of the most abundant lipid mediators present in the airways of asthmatics. However, little was known of the role it plays in the pathophysiology of asthma, until the identification of DP (DP1, PTGDR) and CRTH2 (DP2), two PGD(2)-specific transmembrane receptors with different distribution and intracellular signaling. Pharmacological tools, such as receptor-specific agonists and antagonists, and genetically-engineered mice, which lack either DP or CRTH2, have helped understand the complex effects of PGD(2) in allergic inflammation of the airways. Furthermore, genetic association studies have shown a positive linkage of the genetic polymorphisms in DP and CRTH2, with asthma phenotypes from specific ethnic backgrounds, further highlighting the importance of PGD(2) and its receptors in the pathophysiology of asthma.
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Affiliation(s)
- Tsuyoshi Oguma
- Department of Medicine, Keio University School of Medicine,Tokyo, Japan
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Abstract
PURPOSE OF REVIEW There is wide variation in the global epidemiology of allergic diseases, and the prevalence rates of asthma and allergy differ significantly among different Asian populations. The diversity of environment and ethnic background in Asia provide excellent opportunities for research into the environmental and genetic determinants of asthma and allergies. This review summarizes important lessons learnt from research findings from Asia on asthma and allergy. RECENT FINDINGS Recent epidemiologic studies revealed wide variation and increasing prevalence of asthma and allergy in many Asian countries. Comparative studies of population of the same ethnic background living in different environments revealed important environmental risk factors for asthma. Ambient air pollution plays an important role in the morbidity of patients with asthma but does not seem to affect the prevalence of asthma. There were many genetic association studies for allergic diseases from Asia. These studies identified novel gene targets, such as CD40, DCNP1 and PTGS2, for asthma and allergen sensitization whereas many others replicated the genetic associations on known candidate genes for asthma and atopic dermatitis. SUMMARY Epidemiologic and genetic researches in Asia advance our knowledge on the disease prevalence, healthcare burden and pathogenesis of asthma and allergy.
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Contopoulos-Ioannidis DG, Kouri I, Ioannidis JP. Pharmacogenetics of the response to beta 2 agonist drugs: a systematic overview of the field. Pharmacogenomics 2008; 8:933-58. [PMID: 17716228 DOI: 10.2217/14622416.8.8.933] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The response to beta2-agonist treatment shows large repeatability within individuals and may thus be determined by genetic influences. Here we present a systematic overview of the available genetic association and linkage data for beta2-agonist treatment response. Systematic searches identified 66 eligible articles, as of March 2007, pertaining either to B2AR gene polymorphisms and short-acting or long-acting beta2-agonists or to another 29 different genes. We systematize these study results according to gene, agent and type of outcomes addressed. The systematic review highlights major challenges in the field, including extreme multiplicity of analyses; lack of consensus for main phenotypes of interest; typically small sample sizes; and poor replicability of the proposed genetic variants. Future studies will benefit from standardization of analyses and outcomes, hypothesis-free genome-wide association testing platforms, potentially additional fine mapping around new discovered variants, and large-scale collaborative studies with prospective plans for replication among several teams, with transparent public recording of all data.
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Li J, Liu Q, Wang P, Li H, Wei C, Guo C, Gong Y. Lack of association between three promoter polymorphisms of PTGDR gene and asthma in a Chinese Han population. Int J Immunogenet 2007; 34:353-7. [PMID: 17845306 DOI: 10.1111/j.1744-313x.2007.00699.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The PTGDR gene has been suggested to be an asthma susceptibility gene in previous genome-wide linkage studies as well as in functional studies in a mouse model of asthma. Recently, promoter polymorphisms of the PTGDR gene have been reported to be associated with asthma in American and European populations. In order to determine the association of PTGDR promoter polymorphisms and asthma susceptibility in a Chinese Han population, three promoter single nucleotide polymorphisms (SNP) -549T/C, -441C/T, and -197T/C were genotyped in 336 patients with asthma and 264 healthy controls. Asthma was diagnosed according to the American Thoracic Society (ATS) criteria. SNPs -549T/C and -441C/T were genotyped by Tetra-primer Amplification Refractory Mutation System PCR method and -197T/C by polymerase chain reaction-restriction fragment length polymorphism method. Unlike the results observed in American and European populations, none of the three SNPs nor any haplotypes in the PTGDR promoter region were found to be associated with asthma susceptibility in this Chinese Han population (all P-value > 0.05). The frequencies for both high-transcriptional-efficiency haplotype (CCC) and low-transcriptional-efficiency haplotype (TCT) were lower than 1% in patients and controls, significantly different from those observed in American and European populations. These results suggest that the three PTGDR gene promoter polymorphisms studied are not important risk factors for asthma susceptibility in the Chinese Han population.
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Affiliation(s)
- J Li
- Key Laboratory of Experimental Teratology, Ministry of Education, China
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Finkelman FD, Vercelli D. Advances in asthma, allergy mechanisms, and genetics in 2006. J Allergy Clin Immunol 2007; 120:544-50. [PMID: 17610942 DOI: 10.1016/j.jaci.2007.05.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 05/08/2007] [Accepted: 05/11/2007] [Indexed: 10/23/2022]
Abstract
This review discusses the main advances in animal models of allergic airway disease and genetics of asthma and allergy published in the Journal in 2006. This work highlighted and extended what has become the central dogma of allergic pathogenesis by highlighting the mechanisms involved in inducing a T(H)2 response and in determining how T(H)2 cytokines induce the allergic airway disease phenotype. By so doing, they have identified a considerable number of potential therapeutic targets. Genetic analyses, on the other hand, revealed novel, potentially important candidate genes, confirmed known ones, and refined our understanding of the putative role played by others, sometimes positively, sometimes negatively. These data reiterate allergic inflammation is a classic complex genetic disease-that is, a disorder in which multiple and distinct genetic determinants variously interact with one another and with relevant environmental exposures to result in clinical phenotypes that, although superficially similar, involve distinct genetic pathways and represent the outcome of distinct pathogenetic mechanisms.
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Affiliation(s)
- Fred D Finkelman
- Division of Immunology, University of Cincinnati, Cincinnati, Ohio, USA
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Zhu G, Vestbo J, Lenney W, Silverman M, Whyte M, Helms P, Anderson WH, Pillai SG. Association of PTGDR gene polymorphisms with asthma in two Caucasian populations. Genes Immun 2007; 8:398-403. [PMID: 17538632 DOI: 10.1038/sj.gene.6364399] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The prostanoid DP receptor (PTGDR) is shown to be involved in the asthma patho-physiology and the results from the published genetic association studies are inconsistent. Four single nucleotide polymorphisms (SNPs) in PTGDR were genotyped in 342 and 294 families from UK and Denmark respectively. Asthma and asthma-related phenotypes were analyzed using family-based association analyses. In the UK families, a promoter polymorphism (-731A/G) showed significant associations with asthma (P=0.0022), atopic asthma (P=0.0044), bronchial hyperreactivity or BHR (P=0.00120) and strict asthma (P=0.0008). The P-values for asthma, BHR and strict asthma were significant even after the most stringent correction for the number of markers and the number of phenotypes analyzed (<0.0031). An intronic polymorphism (+6651C/T) also showed significant associations with asthma (P=0.0302), atopic asthma (P=0.0131), BHR (P=0.0249) and strict asthma (P=0.0261). In the Danish families, an intronic polymorphism (+6541C/T) showed significant associations with asthma (P=0.0071), atopic asthma (P=0.0348), BHR (P=0.0033) and strict asthma (P=0.0381). The results of haplotype analyses supported the ones of the single SNP analyses. Thus, we demonstrated significant evidence of association between polymorphisms in PTGDR with asthma phenotypes in the two Caucasian populations.
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Affiliation(s)
- G Zhu
- Medical Genetics, Glaxo SmithKline, Research Triangle Park, NC 27709, USA
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