Development of quantitative analysis method of the atherosclerotic lesions in gene targeted mice

定量分析动脉粥样硬化病变最可靠的方法之一是直接测量组织切片上的病变大小。在本研究中，我们选择了动脉粥样硬化早期发生的主动脉瓣和升主动脉的横截面。以主动脉瓣为标志，很容易定位切片位置。在实际操作中，选择穿过主动脉瓣与升主动脉的4个切片，通过图像分析显微镜系统测量每个切片的动脉粥样硬化面积。通过该方法定量证明，在巨噬细胞清道夫受体（macrophage scavenger receptor， MSR）缺失的情况下，LDL受体缺陷小鼠动脉粥样硬化的进展受到抑制。除MSR外的其他清除率受体，如CD36、MARCO受体和CD68/Macrosialin，被认为与其余病变处巨噬细胞的脂质摄取有关。该方法也可用于抗动脉粥样硬化药物的评价。结果表明，新研制的抗氧化剂BO-653能有效降低ApoE缺陷小鼠的动脉粥样硬化损伤大小。虽然目前的图像分析显微镜系统的引入使我们能够非常方便地对动脉粥样硬化进行定量分析，但最近的研究表明，动脉粥样硬化的性质与急性冠状动脉综合征的危象有关，而不是与动脉狭窄的程度有关。软质动脉粥样硬化富含巨噬细胞，易导致动脉粥样硬化破裂。由此可见，对于动脉粥样硬化病变的评价，仅仅比较病变的大小是不够的，评价动脉粥样硬化本身的病理性质似乎很重要。这似乎是未来的研究课题。

One of the most reliable methods for the quantitative analysis of atherosclerotic lesions is direct measurement of the lesion size on tissue sections. In this study, we selected the cross-sections through the aortic valve and ascending aorta where the atherosclerosis occurs at very early stage. Using the aortic valve as a marker, the place of the sectioning is easily oriented. In practice, the four slices crossing aortic valve and ascending aorta were selected, and the area of atherosclerosis in each section was measured by the image analysis microscope system.Using this method, it was quantitatively proven that the progress of the atherosclerosis in LDL receptor deficient mice was suppressed in the absence of macrophage scavenger receptor (MSR). Other scavenger receptors than MSR such as CD36, MARCO receptor, and CD68/Macrosialin were considered to concern in the lipid uptake of the macrophages at the remaining lesion. This method was also available for the evaluation of anti-atherosclerosis drugs. The measurement showed that a newly developed antioxidant (BO-653) was effective to reduce the atherosclerotic lesion size in ApoE deficient mice.Though the introduction of the present image analysis microscope system enabled us to carry out the quantitative analysis of the atherosclerosis very conveniently, it has been shown recently that the nature of the atheroma is more concerned to the crisis of the acute coronary syndrome than the degree of stenosis of the artery. Soft atheroma which is rich in macrophages is easy to cause atheroma rupture. From this fact, for the evaluation of the atherosclerosis lesion, it was not sufficient to compare the lesion size only, and it seemed to be important to evaluate the pathological nature of the atheroma itself. This seemed to be the future research subject.