摘要目的 探讨A20蛋白基因启动子区rs5029924位点单核苷酸多态性(single nucleotide polymorphism,SNP)与创伤后脓毒症之间的关系. 方法 采用PCR-DNA测序法检测103例创伤脓毒症组(A组)、120例创伤非脓毒症组(B组)、135例健康对照组(对照组)个体基因组rs5029924位点的基因分布,分析不同基因型与脓毒症易感性的关系.体外以脂多糖(lipopolysac charides,LPS)刺激不同基因型健康者的外周血细胞,利用荧光定量PCR技术测定A20 mRNA表达,流式细胞技术测定A20蛋白表达,ELISA技术分析TNF-α及IL-1β水平. 结果 对照组rs5029924的CC、CT、TT基因型频率为77.8％、20.0％和2.2％,而A组、B组分别为63.1％、34.0％、2.9％及83.3％、15.0％、1.7％.A组CC基因型频率显著低于B组及对照组(P＜0.05),而B组与对照组间差异无统计学意义(P＞0.05)；CT/TT基因型患脓毒症的危险性是CC基因型的2.397倍,T等位基因相对C等位基因也能显著增加脓毒症的发病风险(OR=2.056)；LPS刺激后,CC基因型个体外周血白细胞A20 mRNA和蛋白表达水平均显著高于CT/TT,而TNF-α及IL-1β3水平则显著低于CT/TT个体. 结论 rs5029924位点多态性与脓毒症易感性相关,可能是由于突变型通过影响启动子活性而降低A20表达,导致炎症失控.

abstractsObjective To investigate relationship of single nucleotide polymorphism (SNP)at rs5029924 locus in A20 promoter region and posttraumatic sepsis.Methods PCR-DNA sequencing was used to analyze different gene distribution at rs5029924 locus of 103 trauma patients with sepsis (Group A),120 trauma patients without sepsis (Group B) and 135 healthy peoples (control group).Relation of different genotypes at rs5029924 locus to sepsis susceptibility was analyzed.Peripheral blood cells of healthy peoples of different genotypes were stimulated using lipopolysaccharides (LPS) in vitro.Expression of A20 mRNA was measured by fluorescent quantitative PCR,expression of A20 protein by flow cytometry,and levels of TNF-α and IL-1β by ELISA method.Results Frequency of rs5029924 genotypes CC,CT and TT was respective 77.8％,20.0％ and 2.2％ in control group； 63.1％,34.0％ and 2.9％ in Group A； 83.3％,15.0％ and 1.7％ in Group B.Significantly lower frequency of CC genotype was observed in Group A when compared to Group B and control group (P ＜0.05),but no statistical differences were recorded between Group B and control group (P ＞ 0.05).CT/TT genotype increased risk coefficient of sepsis to 2.397-fold higher level when compared to CC genotype.Allele T increased prevalence of sepsis significantly as well (OR =2.056) when compared to allele C.After LPS treatment in vitro,CC genotype individuals revealed significantly higher levels of A20 mRNA and protein in peripheral blood leukocytes,but significantly lower levels of TNF-α and IL-1 β when compared to CT/TT genotype individuals.Conclusion Polymorphism of rs5029924 locus is associated with sepsis susceptibility and the reason may be that mutant genes affect promoter activity and down-regulate A20 expression,which fails to suppress inflammation.