蛋氨酸诱导ApoE基因敲除小鼠主动脉不稳定斑块形成模型的研究  

Methionine induces ApoE gene knockout mice to establish vulnerable aortic plaque model

作　　者：徐志红[1] 陆国平[2] 席锐[2] 吴春芳[2] 

机构地区：[1]上海交通大学医学院附属瑞金医院老年病科,上海200025 [2]上海交通大学医学院附属瑞金医院心脏科,上海200025

出　　处：《上海交通大学学报（医学版）》2010年第9期1115-1120,共6页Journal of Shanghai Jiao tong University:Medical Science

摘　　要：目的通过2%(wt/vol)L-蛋氨酸负荷诱导ApoE基因缺陷小鼠,建立高同型半胱氨酸(Hcy)血症的动脉粥样硬化(AS)易损斑块模型。方法将60只6周龄C57BL/6J系ApoE基因缺陷小鼠随机分为三组,每组20只。对照组:给予同剂量饮用水灌胃;高蛋氨酸组:给予2%(wt/vol)L-蛋氨酸灌胃;极高蛋氨酸组:给予[3%(wt/vol)L-蛋氨酸灌胃。另设正常小鼠作为正常对照组(n=20)。1个月和2月后分别测定血清Hcy和血脂变化,并通过斑块HE、VanGieson(EVG)弹性纤维染色和EVG苦味酸复红法胶原染色及anti-MAC3单克隆抗体标记来检测斑块大小、纤维帽厚度、胶原比例和炎症浸润程度的变化。TUNEL法检测主动脉血管组织中细胞凋亡情况。结果高蛋氨酸负荷可诱导ApoE基因缺陷小鼠AS易损斑块产生,且随负荷提高和时间延长程度加重,与对照组比较差异有统计学意义(P<0.05);凋亡细胞在脂核区大量积聚;内皮细胞水肿变性;血管平滑肌细胞(SMCs)由收缩型向合成型转变,胞质疏松,水肿变性,内质网扩张,胞质内空泡增多以及肌丝溶解;并可见核固缩的凋亡SMCs。结论高蛋氨酸饮食可诱导apoE基因缺陷小鼠出现高Hcy血症,从而生成AS易损斑块。斑块内SMCs增生与凋亡现象并存。Objective To induce vulnerable aortic plaque model in atherosclerosis of homocysteine by 2%（wt/vol） L-methionine in ApoE gene knockout mice.Methods Sixty 6-week old C57BL/6J ApoE gene knockout mice were randomly divided into three groups,with 20 rats in each group.Same amount of drinking water was administered to rats in control group,rats in high methionine group were intragastrically administrated with 2%（wt/vol） L-methionine,and those in extremely higher methionine group were intragastrically administrated with 3%（wt/vol） L-methionine.Besides,another 20 normal rats were served as normal control group.Serum homocysteine and lipid changes were detected one month and two months later,and the changes of plaque size,thickness of fibrous cap,collagen ratio and inflammatory infiltration degree were measured by HE,EVG elastic fiber staining and collagen staining of plaque and anti-MAC3 monoclonal antibody labeling.Cell apoptosis in aortic tissues was determined by TUNEL method.Results High methionine dose-dependently and time-dependently induced the development of vulnerable aortic plaque in atherosclerosis in ApoE gene knockout mice.Vascular smooth muscle cells exhibited increasement of vacuole and lysome,dilatation of endoplasmic reticulum and deformation of mitochondria.The endothelial cells were edematous and deforming.The apoptosis cells existed simultaneously in the lipid core.ConclusionHigh methionine diet could induce hyperhomocysteinemia in ApoE gene knockout mice,which may promote the development of vulnerable plaque in atherosclerosis.Proliferation and apoptosis of vascular smooth muscle cells coexisted in plaque.

关 键 词：同型半胱氨酸 蛋氨酸 APOE基因 动脉粥样硬化 

分 类 号：R541.4[医药卫生—心血管疾病] R-332[医药卫生—内科学]