快速构建不稳定型动脉粥样硬化小鼠模型的方法研究

Rapid establishment of atherosclerosis models with vulnerable plaques in mice

目的:比较研究多种动脉粥样硬化(AS)建模方式,建立一种快速构建不稳定型AS小鼠模型的方法。方法:将6周龄雄性ApoE^(-/-)小鼠随机分为4组,1组给予正常饲料,饲养28周,其余3组给予高脂饲料,分别建模8,12和16周;此外,设置1组C57BL/6小鼠作为对照组,喂养正常饲料28周。实验结束后,称量小鼠体重,取血并收集血浆,用于测定血脂水平;分离、收集主动脉、主动脉根和头臂动脉,进行斑块染色和免疫组化分析。结果:相比于对照组,正常饲喂的ApoE^(-/-)小鼠体内血糖、血脂水平发生紊乱,血管斑块面积显著增加,斑块部位巨噬细胞浸润增加;而高脂饮食诱导进一步加重了ApoE^(-/-)小鼠体内血糖和血脂水平的紊乱程度,导致血管斑块面积和斑块部位巨噬细胞的浸润进一步增加,斑块胶原含量和纤维帽厚度进一步减少;高脂饮食诱导16周后,ApoE^(-/-)小鼠斑块内的坏死核心面积显著增加,纤维帽变薄,形成了不稳定型动脉粥样硬化斑块。结论:采用高脂饮食诱导ApoE^(-/-)小鼠,建模16周,能够快速形成不稳定型动脉粥样硬化斑块,可用于AS斑块不稳定性机理及治疗药物的研究。

Objective: To establish a rapid mouse model of atherosclerosis( AS) bearing vulnerable plaques based on the optimization of feeding high fat food for weeks. Methods: The male ApoE-/-mice( 6-weeks old) were randomly divided into 4 groups. The first group was fed with normal diet for 28 weeks,and the other three groups were fed with commercial high fat food for 8,12 or 16 weeks,respectively. C57 BL/6 mice were fed with normal diet for 28 weeks as control group. At the end of experiments,mice were weighed and their plasma was collected for lipid assay. Moreover,the aortas,aortic root and brachiocephalic artery were separated for lesion staining and immunohistochemistry. Results: Compared with the control group,the ApoE-/-mice on normal diet had abnormal blood glucose and plasma lipid levels,which leaded to lesion augmentation and macrophage infiltration.More severe disorder of plasma lipid levels was found in the ApoE-/-mice on high fat diet,which directly resulted in further lesion augmentation,macrophage infiltration,collagen loss and fibrous cap thinning. After 16 weeks of induction with high-fat diet,the ApoE-/-mice exhibited massive macrophage infiltration in the aortic root plaque where the fibrous cap was thinning over large necrotic core. Conclusion: The optimal method to construct AS models with vulnerable lesions is as follows: 6-weeks old ApoE-/-mice fed with the commercial high-fat food D12079 B for 16 weeks. This standard method might be helpful for the mechanism research of plaque rupture or screening anti-atherosclerosis drugs.