灯盏乙素对小型猪动脉粥样硬化模型颈总动脉斑块组织中基质金属蛋白酶-1、2、9表达的影响

Effects of Scutellarin on Expressions of MMP-1,2,9 in AS Plaques of Experimental Atherosclerotic Minipigs

目的:研究灯盏乙素(scutellarin)对小型猪实验性动脉粥样硬化(atherosclerosis,AS)斑块组织中MMP-1、2、9 mRNA和蛋白表达的影响。方法:实验动物随机分为6组(3只/组):假手术对照组、模型对照组、辛伐他汀2 mg/kg阳性对照组、灯盏乙素1.5 mg/kg、3 mg/kg和6 mg/kg组,均以1 mL/kg·d给药体积腹腔注射给药。假手术对照组动物仅做切开手术,不进行球囊损伤,其余实验组动物采用球囊损伤+高脂饲料喂养复制小型猪动脉粥样硬化模型,组织病理学检查不同剂量灯盏乙素治疗后对小型猪AS病变程度的影响。分别运用RT-PCR、Western blot和免疫组化检测不同剂量的灯盏乙素对小型猪AS模型颈总动脉斑块组织中MMP-1、2、9的mRNA和蛋白表达的影响。结果:病理学结果显示,AS模型对照组动物血管内膜明显增厚、大量胶原纤维沉积、内皮细胞损伤脱落,动脉壁上有不同程度的斑块形成,内有脂质沉积且有泡沫细胞形成。3、6 mg/kg灯盏乙素组治疗后,颈总动脉损伤和病变程度明显减轻,脂质斑块及泡沫细胞减少。与假手术对照组比较,AS模型对照组颈总动脉斑块组织中MMP-1、2、9的mRNA和蛋白表达显著上调(P<0.01)。与AS模型对照组相比,经灯盏乙素治疗后,小型猪颈总动脉斑块组织中MMP-1、2、9的mRNA和蛋白表达显著下调(P<0.01)。结论:灯盏乙素能够通过下调MMP-1、2、9 mRNA和蛋白的表达,减轻小型猪动脉粥样硬化模型颈总动脉血管的损伤和病变程度,且呈量效关系。

Objective:To explore the effects of scutellarin on mRNA and protein expressions of MMP-1,2,9 in AS plaques of experimental atherosclerotic minipigs.Methods:Animals were randomly divided into 6 groups,3 animals in each group:the shame operation group,the model group,the simvastatin positive group(2 mg/kg),scutellarin groups(6 mg/kg,3 mg/kg and 1.5 mg/kg).All animals were injected intraperitoneally with 1 mL/kg body weight daily.The minipigs in the sham operation group only underwent incision without the balloon injury,while high-fat diet combined with balloon injury was used in other experimental groups to replicate the atherosclerotic model.Pathological examination was used to monitor the effects of different doses of scutellarin on the carotid atherosclerosis in minipigs.RT-PCR,Western blot and immunohistochemistry methods were used to determine the effects of different doses of scutellarin on the mRNA and protein expressions of MMP-1,2,9 in AS common carotid artery plaques of minipigs.Results:The pathological results showed that the vascular intima was significantly thickened in the model group,a large amount of collagen fibers were deposited,endothelial cells were damaged and detached,and there were varying degrees of plaque formed on the arterial wall,in which lipid deposition occurred and foam cells formed.After treatment with scutellarin 3 and 6 mg/kg,the injury degree of common carotid artery was significantly alleviated,and the number of lipid plaques and foam cells was decreased.Compared with the sham operation group,the expressions of MMPs(MMP-1,2,9)mRNA and protein were significantly increased in AS model group,(P<0.01).Compared with the model group,the expressions of MMPs(MMP-1,2,9)mRNA and protein were decreased after scutellarin treatment(P<0.01).Conclusion:Scutellarin can significantly reduce the carotid artery injury in experimental atherosclerotic minipigs via down-regulating the mRNA and protein expressions of MMP-1,2,9 in AS plaque,which shows the dose-response relationship.