INSERM U1039, Radiopharmaceutiques Biocliniques, Grenoble, France.
Arterioscler Thromb Vasc Biol. 2011 May;31(5):1007-10. doi: 10.1161/ATVBAHA.111.225227. Epub 2011 Mar 10.
Despite the fact that mechanical stresses are well recognized as key determinants for atherosclerotic plaque rupture, very little is known about stress amplitude and distribution in atherosclerotic lesions, even in the standard apolipoprotein E (apoE)-/- mouse model of atherosclerosis. Our objectives were to combine immunohistology, atomic force microscopy measurements, and finite element computational analysis for the accurate quantification of stress amplitude and distribution in apoE-/- mouse aortic atherosclerotic lesions.
Residual stresses and strains were released by radially cutting aortic arch segments from 7- to 30-week-old pathological apoE-/- (n=25) and healthy control mice (n=20). Immunohistology, atomic force microscopy, and biomechanical modeling taking into account regional residual stresses and strains were performed. Maximum stress values were observed in the normal arterial wall (276±71 kPa), whereas low values (<20 kPa) were observed in all plaque areas. Stress distribution was not correlated to macrophage infiltration.
Low mechanical stress amplitude was observed in apoE-/- mouse aortic atherosclerotic lesions. This original study provides a basis for further investigations aimed at determining whether low stress levels are responsible for the apparently higher stability of murine aortic atherosclerotic lesions.
尽管机械应力已被公认为动脉粥样硬化斑块破裂的关键决定因素，但对于动脉粥样硬化病变中的应力幅度和分布，即使在动脉粥样硬化的标准载脂蛋白 E（apoE）-/-小鼠模型中，也知之甚少。我们的目标是结合免疫组织化学、原子力显微镜测量和有限元计算分析，准确量化 apoE-/-小鼠主动脉粥样硬化病变中的应力幅度和分布。
从 7 至 30 周龄的病理性 apoE-/-（n=25）和健康对照小鼠（n=20）的主动脉弓段中径向切割，以释放残余应力和应变。进行免疫组织化学、原子力显微镜和考虑到局部残余应力和应变的生物力学建模。在正常动脉壁中观察到最大的应力值（276±71kPa），而在所有斑块区域中均观察到较低的应力值（<20kPa）。应力分布与巨噬细胞浸润无关。
在 apoE-/-小鼠主动脉粥样硬化病变中观察到低机械应力幅度。这项原始研究为进一步研究提供了基础，旨在确定低应力水平是否是导致鼠主动脉粥样硬化病变明显更高稳定性的原因。
