ALOX5基因启动子SP-1结合位点多态性与儿童哮喘的相关性研究

Polymorphism of SP-1 binding motif in ALOX5 promoter may be associated with bronchial asthma susceptibility in Chinese Han children

目的探讨ALOX5基因启动子SP-1结合位点多态性和汉族儿童支气管哮喘发生的关联。方法选取88例支气管哮喘儿童为病例组,124例健康儿童为对照组。用聚合酶链反应-单链构象多态性(PCR-SSCP)分析ALOX5基因启动子SP-1结合位点多态性,采用实时荧光逆转PCR检测病例组和对照组ALOX5各基因型儿童外周血ALOX5 mRNA表达量。结果临床资料显示有家族史、非母乳喂养、有过敏史和被动吸烟与儿童支气管哮喘发病相关(P<0.05),性别、年龄差异无统计学意义(P>0.05)。经PCR-SSCP鉴定ALOX5有6种基因型,包括4/4、4/5、4/6、5/5、5/6和6/6;ALOX5基因多态性在汉族儿童中分布符合Hardy-Weirberg平衡(X^2=0.361,P>0.05)。等位基因4及基因型(4/4+4/5)在病例组和对照组中分布差异均有统计学意义(均P<0.05)。健康儿童ALOX5 mRNA表达量(0.20±0.14)显著低于哮喘儿童(0.28±0.15)(P<0.05);基因型(4/4+4/5)个体ALOX5mRNA表达量高于基因型(5/5+5/6)个体(P<0.05),其余各基因型组间差异均无统计学意义(均P>0.05)。结论 ALOX5基因启动子SP-1结合位点多态性可能与汉族儿童支气管哮喘相关,该位点调控ALOX5 mRNA表达。

Objective To investigate the association between polymorphism of SP- 1 binding motif in ALOX5 promoter and bronchial asthma susceptibility in Chinese Han children. Methods Eighty- nine children with bronchial asthma （case group） and 124 healthy children （control group） were enrol ed in the study. Polymerase chain reaction- single strand conforma-tion polymorphism （PCR- SSCP） were applied to detect the polymorphism of ALOX5. Expression ALOX5 mRNA in peripheral blood was analyzed by real- time PCR in different genotypes of case and control groups. Results Clinical data revealed that family history, non- breastfeeding, history of al ergies and passive smoking were the risk factors for bronchial asthma in Han chil-dren （P〈0.05）. Six genotypes of ALOX5 were identified by PCR- SSCP, including 4/4, 4/5, 4/6, 5/5, 5/6 and 6/6 genotypes. ALOX5 polymorphism in Han children was fitted with Hardy- Weinberg balance （χ^2=0.361, P〉0.05）.The distributions of Al ele 4 and genotypes （4/4＋4/5） in the case and control groups showed significant differences （P〈0.05）. Relative expression levels of ALOX5 mRNA in healthy children （0.20±0.14） was significantly lower than that in asthmatic children （0.28± 0.15） （P〈0.05）. The expression level of ALOX5 mRNA in genotypes （4/4＋4/5） individuals was higher than those in genotypes （5/5＋5/6） （P〈0.05）. Conclusion The polymorphism of SP- 1 binding motif in ALOX5 promoter may be associated with the occurrence of bronchial asthma in Chinese Han children, which modulates ALOX5 mRNA expression.