Japanese Foundation for Cardiovascular Research, Funabashi, Japan.
PLoS One. 2012;7(11):e50678. doi: 10.1371/journal.pone.0050678. Epub 2012 Nov 28.
Low-density lipoprotein (LDL) is an important risk factor for coronary artery disease. However, its localization in human coronary plaques is not well understood. The present study was performed to visualize LDL in human coronary artery wall.
(1) The fluorescence characteristic of LDL was investigated by color fluorescent microscopy (CFM) with excitation at 470-nm and emission at 515-nm using Nile blue dye (NB) as a biomarker. (2) Native LDL in 40 normal segments, 42 white plaques and 35 yellow plaques (20 with necrotic core) of human coronary arteries was investigated by color fluorescent angioscopy (CFA) and CFM.
(1) NB elicited a brown, golden and red fluorescence characteristic of LDL, apolipoprotein B-100, and lysophosphatidylcholine/triglyceride, respectively. (2) The % incidence of LDL in normal segments, white, and yellow plaques was 25, 38 and 14 by CFA and 42, 42 and 14 by CFM scan of their luminal surface, respectively, indicating lower incidence (p<0.05) of LDL in yellow plaques than white plaques, and no significant differences in detection sensitivity between CFA and CFM. By CFM transected surface scan, LDL deposited more frequently and more diffusely in white plaques and yellow plaques without necrotic core (NC) than normal segments and yellow plaques with NC. LDL was localized to fibrous cap in yellow plaques with NC. Co-deposition of LDL with other lipid components was observed frequently in white plaques and yellow plaques without NC.
(1) Taken into consideration of the well-known process of coronary plaque growth, the results of the present study suggest that LDL begins to deposit before plaque formation; increasingly deposits with plaque growth, often co-depositing with other lipid components; and disappears after necrotic core formation. (2) CFA is feasible for visualization of LDL in human coronary artery wall.
低密度脂蛋白（LDL）是冠心病的一个重要危险因素。然而，其在人冠状动脉斑块中的定位并不清楚。本研究旨在观察 LDL 在人冠状动脉壁中的定位。
（1）采用尼罗蓝染料（NB）作为生物标志物，通过 470nm 激发和 515nm 发射的彩色荧光显微镜（CFM）研究 LDL 的荧光特征。（2）通过彩色荧光血管镜（CFA）和 CFM 研究 40 个正常节段、42 个白色斑块和 35 个黄色斑块（20 个有坏死核心）中的天然 LDL。
（1）NB 分别呈现出 LDL、载脂蛋白 B-100 和溶血磷脂酰胆碱/甘油三酯的棕、金和红色荧光特征。（2）CFA 显示正常节段、白色和黄色斑块中 LDL 的发生率分别为 25%、38%和 14%，CFM 扫描其管腔表面的发生率分别为 42%、42%和 14%，表明黄色斑块中 LDL 的发生率较低（p<0.05），且 CFA 和 CFM 的检测灵敏度无显著差异。CFM 横切表面扫描显示，白色斑块和无坏死核心（NC）的黄色斑块中，LDL 沉积更频繁且更弥散，而正常节段和有 NC 的黄色斑块则较少。黄色斑块中的 LDL 定位于纤维帽。在无 NC 的白色和黄色斑块中，常观察到 LDL 与其他脂质成分的共同沉积。
（1）考虑到冠状动脉斑块生长的已知过程，本研究结果表明，LDL 在斑块形成之前就开始沉积；随着斑块生长而不断沉积，常与其他脂质成分共同沉积；在坏死核心形成后消失。（2）CFA 可用于观察人冠状动脉壁中的 LDL。
