Altered gene expression of endothelial cell and atherosclerosis.

已有报道在人的主动脉中存在大的内皮细胞，特别是在动脉粥样硬化的病变上。它们有多个核，被称为“多核变异内皮细胞(MVECs)”。微血管内皮细胞表达P53抑癌基因，具有染色体非整倍体。在本研究期间，人们发现MVECs高表达低密度脂蛋白受体，并促进对天然低密度脂蛋白的摄取。最近的研究发现，MVECs表达小窝蛋白，但其密度与典型的小单核内皮细胞相似。然而，MVEC的空洞大小大于TEC。这可能反映了细胞表面低密度脂蛋白受体的过度表达。事实上，低密度脂蛋白-金摄取研究表明，微血管内皮细胞单位细胞表面积上的金粒子数量是对照组的4.5倍。低密度脂蛋白-金颗粒定位于细胞质膜小泡、内皮细胞内小体或溶酶体中，偶见腔面开口，而微血管内皮细胞内颗粒较少。这些结果表明，微血管内皮细胞具有比TEC更大的转运低密度脂蛋白的能力。低密度脂蛋白氧化发生在内皮细胞的细胞质中，尤其是在铁蛋白存在的情况下。低密度脂蛋白的细胞内氧化修饰(IOM-LDL)可被铁络合剂或抗氧化剂阻断。这些观察结果表明，内皮细胞存在IOM-低密度脂蛋白，它是由铁蛋白释放的铁催化的。微血管内皮细胞参与动脉粥样硬化病变的发生和发展。

Existence of large endothelial cells in the human aorta, especially on atherosclerotic lesions has been reported. They have multiple nuclei and are called "multinucleated variant endothelial cells (MVECs)". MVECs express p53 tumor suppressor gene and have chromosomal aneuploidy. During the present study period, it was found that MVECs over -expressed LDL receptor and have enhanced uptake of native LDL.In the latest study, caveolin expression was demonstrated in MVECs, but the density of it is similar to typical small mononuclear endothelial cells (TECs). However, the size of caveoles was greater in MVECs than TECs. This may reflect the overexpression of LDL receptor on the cell surface. In fact, LDL-gold uptake study demonstrated 4.5-fold greater amount of gold particles per cell surface unit area in the MVECs. The LDL-gold particles were located in plasmalemmal vesicles, and in endosomes or lysosomes of MVECs with occasional opening on the abluminal surface, whereas few particles were found in TECs. These findings indicate that MVECs have a greater capacity to transport LDL cholesterol than that of TECs.LDL oxidation was demonstrated in the cytoplasm of ECs, , especially of MVECs when cultured in the presence of ferritin. The intracellular oxidative modification of LDL (IOM-LDL) was blocked by iron chelator or antioxidants. These observations suggest that ECs have IOM-LDL which was catalyzed by iron released from ferritin. MVECs contribute to the development and advancement of atherosclerotic lesions.