Atherosclerosis is characterized by the infiltration of macrophages, accumulation of lipids, activation of endothelial cells and synthesis of extracellular matrix by vascular smooth muscle cells. However, there have been few atomic force microscopy (AFM) studies of the aortic intima in situ in the context of atherosclerosis. By employing a customized liquid cell for AFM, we investigated the aortic intima obtained from male C57BL/6 ApoE-deficient mice (ApoE^−/−) aged 14 weeks and male C57BL/6 ApoE-sufficient mice (ApoE^+/+) aged between 18 and 26 weeks that were fed a high-fat and high-cholesterol diet for 4 weeks and performed force spectroscopy mapping of the biomechanical properties of the intima. In the aortas of ApoE-deficient mice, the intima became stiffer than that of ApoE-sufficient mice. In addition, the cytoskeleton of endothelial cells was enlarged, and extracellular matrix accumulated. The biomechanical properties of the aortic intima are altered in early atherogenesis, which may be induced by the enlargement of the endothelial cell cytoskeleton and the increased synthesis of extracellular matrix by activated smooth muscle cells.

中文翻译：

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原子力显微镜在早期动脉粥样硬化背景下研究主动脉内膜的生物力学特性

动脉粥样硬化的特征是巨噬细胞的浸润、脂质的积累、内皮细胞的活化和血管平滑肌细胞合成细胞外基质。然而，在动脉粥样硬化的背景下，对主动脉内膜原位的原子力显微镜 (AFM) 研究很少。通过为 AFM 使用定制的液体细胞，我们研究了从14 周龄的雄性 C57BL /6 ApoE 缺陷小鼠 (ApoE ^{-/- ) 和雄性 C57BL/6 ApoE 充足小鼠 (ApoE +/+}) 年龄在 18 至 26 周之间，喂食高脂肪和高胆固醇饮食 4 周，并对内膜的生物力学特性进行力光谱映射。在 ApoE 缺陷小鼠的主动脉中，内膜变得比 ApoE 充足小鼠的内膜更硬。此外，内皮细胞的细胞骨架增大，细胞外基质积聚。主动脉内膜的生物力学特性在早期动脉粥样硬化形成中发生了改变，这可能是由于内皮细胞细胞骨架的扩大和活化的平滑肌细胞对细胞外基质的合成增加所致。