金荞麦对克雷伯杆菌肺炎大鼠肺组织中TLR2／4，MyD88 mRNA和IκB-α表达的影响

Effect of Jinqiaomai on expression of TLR2/4,MyD88 mRNA and IκB-α in lung tissue of rats with Klebsiella pneumonia

目的:研究金荞麦对克雷伯杆菌肺炎大鼠肺组织损伤的保护作用机制。方法:复制克雷伯杆菌肺炎大鼠模型。随机将雄性SD大鼠分成对照组、模型组、金荞麦高、中、低剂量组(6,3,1.5 g.kg-1)、左氧氟沙星(25 mg.kg-1)组、金荞麦(3g.kg-1)+左氧氟沙星组(25 mg.kg-1)。测大鼠肺组织匀浆中IL-1β,ICAM-1,INF-γ;电镜观察肺组织的超微结构改变,RT-PCR检测肺组织TLR2/4,MyD88 mRNA表达;采用Western Blot方法分析IκB-α的表达。结果:模型组大鼠的肺脏组织损伤明显,模型组大鼠肺组织匀浆中IL-1β,ICAM-1及INF-γ含量升高(P<0.05或P<0.01),模型组大鼠肺组织中TLR2/4,MyD88 mRNA和IκB-α蛋白异常高表达(P<0.05或P<0.01)。与模型组相比,金荞麦各剂量均能明显降低肺组织匀浆中IL-1β和ICAM-1(P<0.05或P<0.01),金荞麦高剂量可明显降低肺组织匀浆中INF-γ含量(P<0.05),金荞麦高、中剂量可明显降低肺组织中TLR2/4,MyD88 mRNA和IκB-α的表达。结论:TLR2/4,MyD88 mRNA和IκB-α蛋白的表达上调参与了肺炎大鼠肺脏组织的损伤,金荞麦可通过下调其表达来保护肺炎大鼠肺组织的损伤作用。

Objective ： To study the mechanism of protective effect of Jinqiaomai （ JQM ） on lung injury induced by Klebsiella pneumonia in rats. Method ： The model of rats with Klebsiella pneumonia was established. The male SD rats were randomly divided into control group, model group, JQM （6, 3, 1.5 g·kg^-1 ） three groups , levofloxaein （25 mg ·kg^-1 ） group, JQM （3 g ·kg^-1 ） ＋ levofloxacin （25 mg ·kg^-1 ） group. The contents of IL-1/3, ICAM-1 and INF-γ in the lung tissue homogenate were measured by radio- y and Elisa. TLR2/4 mRNA and MyD88 mRNA expression were detected by RT-PCR. IκB-α expression was detected by Western Blot. Result： The rats of model group had obvious lung injury, but those of JQM, JQM ＋ levofloxacin and levofloxacin groups had less injury. The contents of IL-1α, ICAM-1 and INF-γ in lung tissue homogenate and the expressions of TLR2/4 mRNA, MyD88 mRNA and IκB-α in lung of model group were significantly higher than those in the control group （ P 〈 0. 05 or P 〈 0.01 ）, while IL-1β, ICAM-1 and INF--γ of JQM groups were significantly lower than those of model group（P 〈0. 05 or P 〈0. 01 ）. The expressions of TLR2/4 mRNA,MyD88 mRNA and IκB-α of JQM （6,3 g ·kg^-1） groups were significantly lower than those of model group（ P 〈 0. 05 or P 〈 0. 01 ）. Conclusion： The lung injury induced by Klebsiella pneumonia is related to TLR2/4, MyD88 mRNA and IκB-α. To decrease the excessive expression of TLR2/4, MyD88 mRNA and IκB-α might be the main mechanism of protective effect of Jinqiaomai on lung injury.