【作者】 朱莉；

【导师】 周盛年； 董波；

【作者基本信息】 山东大学 ， 神经病学， 2008， 硕士

【摘要】 【目的】通过建立家兔食饵性动脉粥样硬化模型,探讨氟伐他汀对植物血凝素样氧化低密度脂蛋白受体-1(Lectin-like oxidized low-densitylipoprotein receptor-1,LOX-1)蛋白及基因表达的影响,以及其与动脉粥样硬化斑块稳定性的关系,进而阐明LOX-1在动脉粥样硬化发生发展中的重要作用,并为治疗动脉粥样硬化提供一条新的思路。【方法】将24只雄性新西兰大白兔按不同处理方式随机分为3组:正常对照组(control group,C组,n=8)、动脉粥样硬化模型组(atherosclerosis group,AS组,n=8)和氟伐他汀干预组(fluvastatin-treated group,FLUT组,n=8)。C组喂普通饮食,AS组喂高脂饮食,FLUT组喂高脂饮食的同时加用氟伐他汀干预,饲养16周后处死。取胸主动脉,分别行HE染色观察胸主动脉形态学变化,免疫组织化学染色检测LOX-1的蛋白表达水平及巨噬细胞在动脉粥样硬化斑块中的浸润水平,半定量逆转录多聚酶链式反应(reverse transcription polymerase chainreaction,RT-PCR)测定兔胸主动脉中LOX-1基因表达的水平。于0周、16周耳缘静脉取空腹血,测定血清总胆固醇(total cholesterol,TC)和低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)。【结果】1、胸主动脉形态学观察结果显示:AS组胸主动脉内膜明显增厚,管腔明显变窄,FLUT组较AS组内膜明显变薄,管腔显著扩大(P＜0.05),C组无斑块形成,内膜结构正常。2、血脂测定结果:0周时C组、AS组、FLUT组血清总胆固醇的浓度分别为0.81±0.22 mmol/L,0.81±0.21mmol/L,0.82±0.20mmol/L;16周时C组、AS组FLUT组血清总胆固醇的浓度分别为0.75±0.22 mmol/L,38.85±8.15mmol/L,16.68±5.92mmol/L;0周时C组、AS组、FLUT组血清低密度脂蛋白胆固醇的浓度分别为0.49±0.14mmol/L,0.51±0.13mmol/L,0.48±0.11mmol/L;16周时C组、AS组、FLUT组血清低密度脂蛋白胆固醇的浓度分别为0.44±0.04mmol/L,14.05±1.18mmol/L,7.64±0.80mmol/L。16周时AS组、FLUT组血清总胆固醇、低密度脂蛋白胆固醇浓度明显高于C组(P＜0.05),FLUT组与AS组血清总胆固醇、低密度脂蛋白胆固醇浓度有统计学差异(P＜0.05)。C组较0周无统计学差异,AS组与FLUT组均较各自0周时显著升高(P＜0.05)。3、LOX-1免疫组织化学染色分析结果显示:阳性颗粒主要表达在增厚的内膜中内皮细胞和泡沫细胞的胞浆及胞膜,AS组阳性染色信号的平均光密度值为0.2335±0.0149,FLUT组阳性染色信号的平均光密度值为0.1387±0.0129。AS组LOX-1抗原表达明显强于FLUT组(P＜0.05)。4、巨噬细胞免疫组织化学染色分析结果显示:阳性颗粒主要表达在增厚的内膜中巨噬细胞的胞浆部位,从免疫组化结果看,AS组巨噬细胞浸润明显多于正常饮食组(p＜0.01),FLUT组巨噬细胞浸润较高脂饮食组明显减少(P＜0.01)。5、逆转录聚合酶链反应检测结果显示:FLUT组(相对系数0.4215±0.1300)LOX-1 mRNA表达水平明显低于AS组(相对系数1.3617±0.1223,P＜0.05)。【结论】氟伐他汀能够抑制动脉粥样硬化兔胸主动脉LOX-1蛋白及基因的表达,同时明显减少巨噬细胞在动脉粥样硬化斑块中的浸润,这可能是它发挥内皮保护作用,抑制AS及增加AS斑块稳定性的机制之一。更多还原

【Abstract】 [Objective] To explore the intervention effects of fluvastatin on expression of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) and observe the relationship between expression of LOX-1 and the stability of atherosclerotic plaque, further elucidate the important role of LOX-1 during the development of atherosclerosis and provide a new thinking for the atherosclerotic treatment.[Methods] Twenty-four male NewZealand white rabbits were randomly and equally divided into three groups: control group(C group, n=8), fed with normal diet;atherosclerosis group(AS group, n=8), fed with high lipids diet and fluvastatin-treated group(FLUT group, n=8), fed with high lipids diet and treated with fluvastatin. They were fed for 16 weeks, the thoracic aortae were harvested, the concentrations of serum total cholesterol (TC) and low-density lipoprotein cholesterol(LDL-C) were measured. We used hematoxylin and eosin (HE) staining to observe the morphology of thoracic aortae and immunohistochemical staining to measure the expression of LOX-1 protein, the soakage of the macrophage in plaques was also examined by immunohistochemitry.The LOX-1 mRNA was analyzed by RT-PCR.[Results]1. The morphology of the thoracic aorta:the intima of thoracic aorta in fluvastatin-treated group was thinner than that in AS group(P<0.05), and the lumina of thoracic aorta in fluvastatin-treated group was larger than that in AS group(P<0.05),the intima structure of thoracic aorta in C group was normal, there was no plaque in it.2. The concentration of serum TC and LDL-C in AS group and FLUT group at 16 weeks was significant higher than that at 0 weeks (P<0.05), there was significant difference between AS group and FLUT group(P<0.05).3. The immunohistochemical staining results of LOX-1 : the buffy particle mainly expressed on plasm and membrane of endothelial cells and foam cells in incrassate intima , the average optical density value of LOX-1 positive staining signal in AS group and FLUT group was 0.2335±0.0149, 0.1387±0.0129, respectively, with significant difference between them(P<0.05).4. The immunohistochemical staining results of macrophage:the soakage of the macrophage in atherosclerotic plaque of AS group and FLUT group was significant higher than those of control group (p<0.05); the soakage of the macrophage in atherosclerotic plaque of FLUT group was significant lower than AS group(p<0.05).5. The relative value of LOX-1 mRNA in AS group and FLUT group was 0.6870±0.1278, 0.4300±0.1415, respectively, with significant difference between them(P<0.05).[Conclusion] Fluvastatin could inhibit the expression of LOX-1 and the soakage of macrophage in atherosclerotic plaques in aorta of atherosclerotic rabbit by significantly lowering serum TC and LDL-C, which may be one of mechanisms of its effect on endothelial protection and stabilizing the atherosclerotic plaques .更多还原