Department of Immunopathology, Faculty of Medical Science and Postgraduate Training, Medical University of Lodz, Pomorska 251 str, 92-213 Lodz, Poland.
BMC Immunol. 2009 Dec 15;10:63. doi: 10.1186/1471-2172-10-63.
Cysteinyl leukotrienes are potent inflammatory mediators implicated in the pathogenesis of asthma. Human cysteinyl leukotriene receptor 1 (CYSLTR1) gene contains five exons that are variably spliced. Within its promoter few polymorphisms were described. To date, there has been no evidence about the expression of different splice variants of CysLT1 in asthma and their association with CYSLTR1 promoter polymorphisms.The goal of our study was to investigate CysLT1 alternative transcripts expression in asthmatic patients with different CYSLTR1 promoter haplotypes.The study groups consisted of 44 patients with asthma, diagnosed according to GINA 2008 criteria and 18 healthy subjects. Genomic DNA and total RNA was extracted from peripheral blood mononuclear cells. Real-time PCR was performed with specific primers for transcript I [GenBank:DQ131799] and II [GenBank:DQ131800]. Fragments of the CYSLTR1 promoter were amplified by PCR and sequenced directly to identify four single nucleotide polymorphisms: C/T [SNP:rs321029], A/C [SNP:rs2637204], A/G [SNP:rs2806489] and C/T [SNP:rs7066737].
The expression of CysLT1 transcript I and II in asthma did not differ from its expression in healthy control group. However, in major alleles homozygotic CAAC/CAAC women with asthma we found significantly higher expression of transcript I as compared to heterozygous CAAC/TCGC women in that loci. CysLT1 transcript I expression tended to negative correlation with episodes of acute respiratory infection in our asthmatic population. Moreover, expression of CysLT1 transcript II in CAAC/CAAC homozygotic women with asthma was significantly lower than in CAAC/CAAC healthy control females.
Genetic variants of CYSLTR1 promoter might be associated with gender specific expression of CysLT1 alternative transcripts in patients with asthma. CysLT1 splice variants expression might also correlate with the susceptibility to infection in asthmatic population.
半胱氨酰白三烯是一种强有力的炎症介质，参与哮喘的发病机制。人类半胱氨酰白三烯受体 1（CYSLTR1）基因包含五个可变剪接的外显子。在其启动子中，已经描述了少数多态性。迄今为止，尚无关于哮喘患者中 CysLT1 不同剪接变体的表达及其与 CYSLTR1 启动子多态性的关联的证据。我们的研究目的是研究不同 CYSLTR1 启动子单倍型的哮喘患者中 CysLT1 替代转录本的表达。研究组包括 44 名根据 GINA 2008 标准诊断为哮喘的患者和 18 名健康受试者。从外周血单核细胞中提取基因组 DNA 和总 RNA。使用转录本 I [GenBank:DQ131799]和 II [GenBank:DQ131800]的特异性引物进行实时 PCR。通过 PCR 扩增 CYSLTR1 启动子片段，并直接测序以鉴定四个单核苷酸多态性：C/T [SNP:rs321029]、A/C [SNP:rs2637204]、A/G [SNP:rs2806489]和 C/T [SNP:rs7066737]。
哮喘患者中 CysLT1 转录本 I 和 II 的表达与健康对照组无差异。然而，在哮喘中主要等位基因纯合 CAAC/CAAC 的女性中，与该位点杂合 CAAC/TCGC 的女性相比，我们发现转录本 I 的表达显著升高。在我们的哮喘人群中，CysLT1 转录本 I 的表达倾向于与急性呼吸道感染发作呈负相关。此外，哮喘中 CAAC/CAAC 纯合女性的 CysLT1 转录本 II 的表达明显低于 CAAC/CAAC 健康对照组女性。
CYSLTR1 启动子的遗传变异可能与哮喘患者中 CysLT1 替代转录本的性别特异性表达相关。CysLT1 剪接变体的表达也可能与哮喘人群中感染的易感性相关。
