槲皮素对矽肺大鼠转化生长因子β1信号转导通路的调节作用

Regulation of Quercetin on Expression of TGF-β1 Singal Transduction Pathway in Lung of Silicotic Rats

[目的]观察槲皮素(quercetin)对矽肺大鼠转化生长因子β1(transforming growth factor beta 1,TGF-β1)信号转导通路的调节作用。[方法]将75只SPF(specific-pathogen-free)级Wistar雄性大鼠随机分为对照组、模型组、槲皮素治疗组,每组25只。模型组与槲皮素治疗组大鼠采用非暴露法气管内一次性注入二氧化硅(SiO2)悬液(250 mg/kg)复制动物矽肺模型。槲皮素治疗组自注射SiO2后每天腹腔注射含50 mg/kg槲皮素的生理盐水1.0 mL,对照组以同样方法注入等量生理盐水,共连续处理14 d。分别在注射SiO2后第3、7、14、21、28天处死动物。应用羟脯氨酸试剂盒检测肺组织中总胶原蛋白含量,免疫组织化学法检测肺组织TGF-β1表达,蛋白免疫印迹(Western blot)法检测TGF-β1直接底物p-Smad3/7蛋白表达情况。[结果]模型组肺组织中总胶原蛋白含量与同期对照组比较明显增加,分别是对照组的6.28、13.11、11.59倍(P<0.01)。槲皮素治疗组与模型组相比,总胶原蛋白含量明显下降,分别是同期模型组的43.05%、38.92%、37.40%(P<0.01)。槲皮素治疗组的TGF-β1阳性表达低于模型组,而明显高于对照组;各时间点与对照组比较,差异有统计学意义(P<0.01,P<0.05)。模型组大鼠肺组织中p-Smad3表达量高于对照组及槲皮素治疗组;各时间点比较,差异均有统计学意义(P<0.01)。槲皮素治疗组各时间点与相应模型组相比,p-Smad3表达减少,但仍高于相应对照组(P<0.01)。模型组大鼠肺组织中p-Smad7表达量低于对照组及槲皮素治疗组;各时间点比较,差异均有统计学意义(P<0.01)。槲皮素治疗组各时间点与对照组、模型组相比,p-Smad7表达量升高(P<0.01)。[结论]槲皮素通过减少Smad3蛋白表达,增加Smad7蛋白表达,抑制矽肺过程中胶原蛋白的产生。

[Objective] To explore the regulation role of quercetin on the expression of transforming growth factor （TGF）-beta 1 signal transduction pathway in the lung of silicotic rats. [Methods] Totally 75 specific-pathogen-free （SPF） male Wistar rats were randomly divided into three groups： a control group, a model group, and a quercetin group. The rat silicosis model was induced by intratracheal instillation of silicosis （250 mg/kg） , and the quercetin group was treated by quercetin with 50 mg/kg/1.0 mL saline after injection of SiO2, while the rats in the control group were given sodium chloride in the same condition. The rats in all groups were put to death on the 3th, 7th, 14th, 21th, 28th days after the silicosis model established. The content of total collagen in lung tissue was determined by hydroxyproline kits. The expression of TGF-β1 protein and p-Smad3/7 in lung tissue samples were evaluated by immunohistochemistry and Western blot technique. [Results] The contents of total collagen in the model group were 6.28, 13.11, 11.59 times of the values in the controls in the same periods respectively （P 〈 0.01）. The contents of total collagen in the quercetin group were 43.05%, 38.92%, and 37.40% of the corresponding values in the model group in the same periods respectively （P 〈 0.01）. The expression levels of TGF-β1 were lower in the quercetin group than in the model group in the same periods and higher than in the control group （P 〈 0.01 and P 〈 0.05, respectively）. The expression levels of p-Smad3 were higher in the model group than in the quercetin group and in the control group in the same periods （P 〈 0.01）, but were lower in the quercetin group than in the model group and higher than in the control group in the same periods （P 〈 0.01）. The expression levels of p-Smad7 were lower in the model group than in the control group and in the quercetin group in the same periods （P 〈 0.01）, but were higher in the quercetin group than in the model group or in the control group at each designed time spot （P 〈 0.01）. [Conclusion] Quercetin could lower the expression of Smad3, increase the expression of Smad7, and then inhibit the collagen protein in silicotic rats.