Objective To explore the effect and mechanism of Toll like receptors 4(TLR4)in airway inflammation of asthma. Methods Asthma model were established in rats , the asthma airway smooth muscle cells (ASMCs) were isolated and cultured, and then randomly divided into control group and transfection group after spread to 6 generations, the transfection group was transfected using small molecule RNA interference technology and lipofection method, the control group was blank control. Levels of IL-5 ,IL-8 in cell culture supernatant were detected by ELISA , the expression of TLR4 protein and mRNA in cells were detected by RT-PCR and Western blot, 24 las after culture. Results The levels of IL-5, IL-8 and the expression of TLR4 protein and mRNA in transfection group were significantly lower than those in control group ( P ＜0.01 ). Conclusions TLR4 may aggravate the airway inflammation by contributing to synthesis and secretion of IL-5, IL-8 in asthmatic ASMCs,which provides a theoretical basis for the clinical targeted therapy.%目的 探讨TOLL样受体4(TLR4)在哮喘气道炎症反应中的作用及机制.方法 建立哮喘大鼠模型,分离、培养其气道平滑肌细胞(ASMCs),传至6代后随机分为转染组和对照组,转染组应用小分子RNA干扰技术、脂质体转染法进行小干扰RNA(siRNA)-TLR4转染,对照组为空白对照.培养24 h后应用ELISA法检测两组细胞培养上清液中IL-5、IL-8水平,应用RT-PCR和Western-blot法检测细胞中TLR4 mRNA和蛋白表达水平.结果 转染组IL-5、IL-8水平及TLR4 mRNA、蛋白表达水平均显著低于对照组(P均＜0.01).结论 TLR4可能通过促进ASMCs合成分泌IL-5、IL-8而加重哮喘气道炎症反应,此为临床靶向治疗提供了理论依据.
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