Tenascin-C在小鼠动脉粥样硬化斑块中的表达及靶向MR体内成像的实验研究

发布时间：2018-06-25 04:28

本文选题：动脉粥样硬化 + 载脂蛋白E类　；参考：《南京医科大学》2017年硕士论文

【摘要】：目的1.检测Tenascin-C在ApoE-/-小鼠动脉粥样硬化斑块形成过程中,不同时期(4、8、16、24、32w)表达的动态变化,探讨其表达特性。2.探讨MR靶向探针anti-Tenascin-C-USPIO在动脉粥样硬化斑块中的特异性成像,为临床动脉粥样硬化分子成像的应用提供实验依据。材料和方法1.取ApoE基因敲除(ApoE-/-)小鼠50只,高脂饲料喂养,建立小鼠动脉粥样硬化(AS)模型,C57BL/6小鼠50只为同源对照组,普通饮食喂养。分别于喂养第4、8、16、24、32周(w)时处死小鼠,检测血脂,显微镜观察斑块病理改变并进行定量分析,免疫组织化学方法检测动脉粥样硬化斑块内Tenascin-C的表达。2.20只ApoE-/-小鼠予高脂饮食喂养建立动脉粥样硬化模型,将其分为靶向探针组10只,对照组10只,分别喂养至16、24w,探针组注射anti-Tenascin-C-USPIO,对照组注射单纯USPIO(n=5/组/周),于注射24h后进行7.0T MR成像,检测斑块信号改变。成像后立刻取主动脉标本进行Tenascin-C免疫组化染色,并行普鲁士蓝染色,观察斑块内铁沉积。结果1.模型组总胆固醇(TC)、低密度脂蛋白(LDL)水平均高于对照组(P均0.05)。随着造模时间的进展,模型组斑块面积及斑块面积/管腔面积比值不断增加,各时期比较均有统计学意义(P0.05)。模型组斑块内Tenascin-C表达量随着AS进展而升高,AS 32w小鼠斑块内部Tenascin-C表达升高最显著,高于8、16、24w 小鼠(0.49±0.07vs0.04±0.02,0.12±0.03,0.21±0.04,P0.05)。2.靶向探针组的斑块信号改变率较对照组明显降低(16w:-15.65 ±0.78%vs.-3.43 ± 2.57%;24w:-26.38 ± 1.54%vs.-11.12 ± 1.60%,P0.05)。并且在靶向探针组中,24w时斑块的信号改变率较16w亦明显降低(P0.05)。免疫组化染色显示探针组Tenascin-C随着斑块进展表达升高,与MR图像斑块信号改变程度相一致。普鲁士蓝染色显示探针组斑块内较多蓝染颗粒,而对照组则极少。结论1.Tenascin-C的表达量随着斑块进展不断增加,主要表达于脂核周围及破裂的纤维帽中,Tenascin-C的表达水平变化可能与动脉粥样硬化进展及斑块不稳定性有关。2.7.0TMR可以对ApoE-/-小鼠动脉粥样硬化斑块模型进行活体评估。anti-Tenascin-C-USPIO探针可实现小鼠动脉粥样硬化斑块的靶向MR体内成像,用于监测斑块的进展,为动脉粥样硬化分子成像的进一步开展奠定了基础。
[Abstract]:Objective 1. To detect the dynamic changes of Tenascin-C expression in ApoE-r-mouse atherosclerotic plaques (ApoE-R-mice) at different stages (4 ~ 816 ~ 24 ~ 32w) and to explore its expression characteristics. 2. To investigate the specific imaging of Mr targeted probe anti-Tenascin-C-USPIO in atherosclerotic plaques, and to provide experimental evidence for the application of molecular imaging in clinical atherosclerosis. Materials and methods 1. Fifty ApoE knockout mice were fed with high fat diet and 50 C57BL / 6 mice were fed with common diet. The mice were killed after feeding for (w) at the 4th week of 816 and 2432 weeks, the blood lipids were detected, the pathological changes of plaques were observed by microscope and quantitative analysis was made. Immunohistochemical method was used to detect the expression of Tenascin-C in atherosclerotic plaques. 2.20 ApoE-r-mices were fed with high-fat diet to establish atherosclerosis model. They were divided into target probe group (n = 10) and control group (n = 10). The probe group was injected with anti-Tenascin-C-USPIOand the control group was injected with simple USPIO (5 / week). After 24 hours of injection, 7.0T Mr imaging was performed to detect the changes of plaque signal. Immediately after imaging, the aortic specimens were stained with Tenascin-C immunohistochemical staining and Prussian blue staining to observe the iron deposition in the plaques. Result 1. The levels of total cholesterol (TC) and low density lipoprotein (LDL) in the model group were higher than those in the control group (P 0.05). With the progress of modeling time the plaque area and plaque area / lumen area ratio in the model group increased continuously and there were significant differences in each period (P0.05). The expression of Tenascin-C in atherosclerotic plaques in the model group was significantly increased with the progression of atherosclerosis. The expression of Tenascin-C in the atherosclerotic plaques was significantly higher than that in the mice at 816 ~ 24w (0.49 卤0.07vs0.04 卤0.02 卤0.12 卤0.03 卤0.21 卤0.04p0.05) .2.The expression of Tenascin-C in atherosclerotic plaques was significantly higher than that in the control group. The change rate of plaque signal in the target probe group was significantly lower than that in the control group (16w:-15.65 卤0.78%vs.-3.43 卤2.57B, 24w: -26.38 卤1.54%vs.-11.12 卤1.60,P0.05). In the target probe group, the signal change rate of plaque at 24 weeks was significantly lower than that of 16 weeks (P0.05). Immunohistochemical staining showed that the expression of Tenascin-C in the probe group increased with the progression of plaque, which was consistent with the change of plaque signal in Mr images. Prussian blue staining showed that there were more blue-stained granules in the probe group than in the control group. Conclusions 1. The expression of Tenascin-C increased with the progression of plaque. The expression level of Tenascin-C mainly expressed around the adipoid nucleus and in the ruptured fibrous cap may be related to the progression of atherosclerosis and plaque instability. 2.7.0 TMR can be used to evaluate the ApoE-r-mouse model of atherosclerotic plaque in vivo. Anti-Tenascin-C-USPIO probe. In vivo Mr imaging of atherosclerotic plaques in mice can be achieved by acupuncture. It can be used to monitor the progress of plaque and lay the foundation for further development of atherosclerotic molecular imaging.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R543.5;R445.2

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