Previous studies have demonstrated the important role of angiotension II(AngII)in promoting proliferation of myofibroblasts(myoFbs)and myocardial fibrosis.However,the underlying mechanisms and the role of oxygen free ...Previous studies have demonstrated the important role of angiotension II(AngII)in promoting proliferation of myofibroblasts(myoFbs)and myocardial fibrosis.However,the underlying mechanisms and the role of oxygen free radicals in the proliferation of myofibroblasts induced by AngII are unclear.The present study was designed to shed light on this issue through exploration of AngII signaling pathways via in vitro experiments.Primary cultures of neonatal rat myoFbs were divided into five groups which were treated with AngII(10^(-8) to 10^(-6) M),AngII with the antioxidant N-acetyl-L-cysteine(NAC),or normal culture medium.We observed the proliferation of myoFbs as induced by AngII at different concentrations with MTT.Reactive oxygen species(ROS)levels in myoFbs were detected by monitoring the fluorescence of 2',7'-dichlorofluorescein.The contents and levels of oxygen free radicals(OH·)in the three groups were detected by spectrophotometer,immunocytochemical staining,and confocal fluorescence.Western blot and image analysis were used to measure membrane translocation and expression of phospho-protein kinase Ca.MyoFbs incubated with AngII(10^(-8) to 10^(-6) M)for 24 h increased their rate of proliferation,the content of OH·,and expression of ROS(P<0.01 vs.control group),whereas these parameters decreased in the presence of NAC.Immunocytochemistry,confocal fluorescence staining and image analysis showed that AngII could promote the translocation and expression of p-PKCα in membrane,and the antioxidant NAC blocked this increase(P<0.01).Western blot results also showed that NAC could inhibit the expression of p-PKCα.展开更多
目的观察吉法酯对双氯芬酸所致大鼠小肠损伤的预防作用,探讨其可能的预防保护机制。方法用小剂量双氯芬酸灌胃制备大鼠NSAID相关小肠损伤模型,24只健康雄性SD大鼠按照随机数字表法等分成3组:空白对照组、实验对照组、吉法酯保护组。空...目的观察吉法酯对双氯芬酸所致大鼠小肠损伤的预防作用,探讨其可能的预防保护机制。方法用小剂量双氯芬酸灌胃制备大鼠NSAID相关小肠损伤模型,24只健康雄性SD大鼠按照随机数字表法等分成3组:空白对照组、实验对照组、吉法酯保护组。空白对照组按10 ml·kg-1·d-1体质量生理盐水灌胃1次;实验对照组按7.8 mg·kg-1·d-1双氯芬酸溶液灌胃1次;吉法酯保护组造模前1天予吉法酯31.25 ml·kg-1·d-1灌胃1次;次日起,同等剂量吉法酯灌胃1 h后再予双氯芬酸7.8 ml·kg-1·d-1灌胃1次。5 d后处死所有大鼠,观察各组大鼠小肠黏膜大体及病理组织学改变,检测小肠上皮AngⅡ、NF-κB表达及血清TNF-α变化。结果小剂量双氯芬酸可致大鼠小肠黏膜广泛糜烂、多发溃疡,甚至出血、穿孔。吉法酯干预后,大鼠肠黏膜损伤明显减轻,多以肠黏膜局部充血、糜烂为主。实验对照组大鼠小肠大体损伤评分(4.38±1.41)及组织学评分(4.00±1.85)均较空白对照组(0.00±0.00;0.00±0.00)显著升高(P均<0.01);吉法酯保护组大体损伤评分(1.13±1.36)及组织学评分(1.75±0.71)均明显低于实验对照组(P均<0.05)。实验对照组血清TNF-α、肠黏膜NF-κB以及AngⅡ表达均明显高于空白对照组(22.20±5.42 vs 6.19±2.76、5.75±0.46 vs 1.38±1.19、4.33±1.51 vs 1.88±0.83,P均<0.05);通过吉法酯干预,血清TNF-α水平(13.03±6.30)较实验对照组显著降低,肠黏膜NF-κB表达(0.25±0.46)以及AngⅡ表达(1.50±1.31)均较实验对照组明显下降(P均<0.05)。结论吉法酯可下调炎症因子AngⅡ、NF-κB的表达,减少炎症因子TNF-α的释放,对双氯芬酸所致大鼠小肠黏膜损伤具有一定保护作用。展开更多
基金This study was supported by the National Basic Research Program(also called 973 Program No.2007CB512006)the National Natural Science Foundation of China(No.30873066/C180102).
文摘Previous studies have demonstrated the important role of angiotension II(AngII)in promoting proliferation of myofibroblasts(myoFbs)and myocardial fibrosis.However,the underlying mechanisms and the role of oxygen free radicals in the proliferation of myofibroblasts induced by AngII are unclear.The present study was designed to shed light on this issue through exploration of AngII signaling pathways via in vitro experiments.Primary cultures of neonatal rat myoFbs were divided into five groups which were treated with AngII(10^(-8) to 10^(-6) M),AngII with the antioxidant N-acetyl-L-cysteine(NAC),or normal culture medium.We observed the proliferation of myoFbs as induced by AngII at different concentrations with MTT.Reactive oxygen species(ROS)levels in myoFbs were detected by monitoring the fluorescence of 2',7'-dichlorofluorescein.The contents and levels of oxygen free radicals(OH·)in the three groups were detected by spectrophotometer,immunocytochemical staining,and confocal fluorescence.Western blot and image analysis were used to measure membrane translocation and expression of phospho-protein kinase Ca.MyoFbs incubated with AngII(10^(-8) to 10^(-6) M)for 24 h increased their rate of proliferation,the content of OH·,and expression of ROS(P<0.01 vs.control group),whereas these parameters decreased in the presence of NAC.Immunocytochemistry,confocal fluorescence staining and image analysis showed that AngII could promote the translocation and expression of p-PKCα in membrane,and the antioxidant NAC blocked this increase(P<0.01).Western blot results also showed that NAC could inhibit the expression of p-PKCα.
文摘目的观察吉法酯对双氯芬酸所致大鼠小肠损伤的预防作用,探讨其可能的预防保护机制。方法用小剂量双氯芬酸灌胃制备大鼠NSAID相关小肠损伤模型,24只健康雄性SD大鼠按照随机数字表法等分成3组:空白对照组、实验对照组、吉法酯保护组。空白对照组按10 ml·kg-1·d-1体质量生理盐水灌胃1次;实验对照组按7.8 mg·kg-1·d-1双氯芬酸溶液灌胃1次;吉法酯保护组造模前1天予吉法酯31.25 ml·kg-1·d-1灌胃1次;次日起,同等剂量吉法酯灌胃1 h后再予双氯芬酸7.8 ml·kg-1·d-1灌胃1次。5 d后处死所有大鼠,观察各组大鼠小肠黏膜大体及病理组织学改变,检测小肠上皮AngⅡ、NF-κB表达及血清TNF-α变化。结果小剂量双氯芬酸可致大鼠小肠黏膜广泛糜烂、多发溃疡,甚至出血、穿孔。吉法酯干预后,大鼠肠黏膜损伤明显减轻,多以肠黏膜局部充血、糜烂为主。实验对照组大鼠小肠大体损伤评分(4.38±1.41)及组织学评分(4.00±1.85)均较空白对照组(0.00±0.00;0.00±0.00)显著升高(P均<0.01);吉法酯保护组大体损伤评分(1.13±1.36)及组织学评分(1.75±0.71)均明显低于实验对照组(P均<0.05)。实验对照组血清TNF-α、肠黏膜NF-κB以及AngⅡ表达均明显高于空白对照组(22.20±5.42 vs 6.19±2.76、5.75±0.46 vs 1.38±1.19、4.33±1.51 vs 1.88±0.83,P均<0.05);通过吉法酯干预,血清TNF-α水平(13.03±6.30)较实验对照组显著降低,肠黏膜NF-κB表达(0.25±0.46)以及AngⅡ表达(1.50±1.31)均较实验对照组明显下降(P均<0.05)。结论吉法酯可下调炎症因子AngⅡ、NF-κB的表达,减少炎症因子TNF-α的释放,对双氯芬酸所致大鼠小肠黏膜损伤具有一定保护作用。
