云南汉族人群Tim-3基因启动子区多态性与支气管哮喘的关联研究

Association Analysis of Tim-3 Promoter Polymorphism With Bronchial Asthma in a Han Population of Yunnan Province

目的阐明Tim-3基因多态性及其mRNA表达水平与云南汉族人群支气管哮喘发病之间的关联。方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法和熔解曲线法,对180名云南汉族支气管哮喘患者和180名健康体检者Tim-3启动子区位点-1516G>T和-574T>G的基因多态性进行检测,同时采用逆转录-实时定量PCR(qRT-PCR)的方法检测和分析支气管哮喘组和健康体检组样本之间Tim-3mRNA的表达差异,并采用散射比浊测定法检测样本血浆中IgE的水平。结果Tim-3启动子区多态性位点-1516G>T和-574T>G的基因型及等位基因频率差异在支气管哮喘病人组和健康体检组之间具有统计学意义(P<0.05);支气管哮喘组和健康体检组中Tim-3的mRNA表达有明显差异(P<0.001);支气管哮喘组和健康体检组中血浆IgE的表达有明显差异(P<0.001);支气管哮喘病人两位点TT基因型Tim-3mRNA表达水平均高于GG型和GT型;携带Tim-3-1516GT基因型的支气管哮喘病人,IgE表达高于GG基因型,携带Tim-3-574GG和GT的支气管哮喘病人,其IgE表达明显高于携带Tim-3-574TT基因型的病人。结论云南汉族人群Tim-3启动子区多态性位点-1516G>T和-574T>G的基因多态性与支气管哮喘遗传易感性相关;相比于健康体检者,支气管哮喘组患者的Tim-3mRNA和IgE的表达明显升高;支气管哮喘者Tim-3基因两位点不同基因型会影响Tim-3mRNA和血浆IgE的表达水平。

Objective To clarify the association between Tim-3 gene polymorphism and its mRNA expression level and the incidence of bronchial asthma(BA)in Yunnan Han population.Methods Polymerase chain reaction-restriction fragment length polymorphism analysis(PCR-RFLP)and Melting curve method were used to detect the polymorphisms of-1516 G>T and-574 T>G sites of Tim-3 gene in 180 BA patients and 180 controls,at the same time,qRT-PCR and turbidimetry were used to detect the expression level of Tim-3 mRNA and plasma total immunoglobulin E(IgE)in disease group and healthy group.Results There were statistically significant differences in genotype and allele frequency of-1516 G>T and-574 T>G between BA and control groups(P<0.05);There was a statistically significant difference in the expression of Tim-3 mRNA between the BA and control group(P<0.05)and there was also a statistically significant difference in plasma IgE levels between the BA and control group(P<0.001);The mRNA expression level of TT genotype of two sites in BA patients was higher than that of GG and GT genotype;Patients carrying Tim-3-1516 GT genotype has higher IgE lever than patients carrying GG genotype,patients carrying Tim-3-574 GG and GT genotypes had significantly higher IgE levels than patients carrying-574 TT genotype.Conclusion The polymorphism of-1516 G>T and-574 T>G gene polymorphisms in the Tim-3 promoter region of the Han population in Yunnan is associated with genetic susceptibility to BA;Compared with healthy people,the expression of Tim-3 mRNA and IgE in patients with BA is significantly increased;In BA group,different genotypes of two sites of Tim-3 gene will affect the expression levels of TIM-3 mRNA and plasma IgE.