MODIFICATION OF LOW-DENSITY LIPOPROTEIN BY ENDOTHELIAL-CELLS INVOLVES LIPID-PEROXIDATION AND DEGRADATION OF LOW-DENSITY LIPOPROTEIN PHOSPHOLIPIDS
MODIFICATION OF LOW-DENSITY LIPOPROTEIN BY ENDOTHELIAL-CELLS INVOLVES LIPID-PEROXIDATION AND DEGRADATION OF LOW-DENSITY LIPOPROTEIN PHOSPHOLIPIDS
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DOI：
10.1073/pnas.81.12.3883
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发表时间：
1984-01-01
期刊：
影响因子：
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通讯作者：
STEINBERG, D
中科院分区：
文献类型：
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作者：
STEINBRECHER, UP;PARTHASARATHY, S;STEINBERG, D
低密度脂蛋白（LDL）与来自兔主动脉或人脐静脉的培养内皮细胞一起孵育时，会在几个方面发生改变（内皮细胞修饰的）。它被巨噬细胞降解的速度比在无细胞情况下类似孵育或与成纤维细胞一起孵育的LDL快得多。它的电泳迁移率增加，密度增加。抗氧化剂可完全阻止这些变化。如果培养基中的过渡金属用EDTA螯合，这些变化就不会发生。在内皮细胞修饰过程中，多达40%的LDL磷脂酰胆碱通过一种类似磷脂酶A2的活性被降解为溶血磷脂酰胆碱。当选择无细胞的孵育条件以通过延长低浓度LDL的孵育时间或增加Cu2 +浓度来促进氧化时，LDL发生的变化与在有细胞存在时非常相似，包括磷脂酰胆碱的降解。一些磷脂酶活性似乎与这些研究中使用的分离的LDL有关。提示存在一个复杂的过程，即内皮细胞通过涉及自由基产生和磷脂酶作用的机制来修饰LDL。
Low density lipoprotein (LDL) incubated with cultured endothelial cells from rabbit aorta or human umbilical vein is altered in several ways (EC-modified). It is degraded by macrophages much faster than LDL similarly incubated in the absence of cells or incubated with fibroblasts. Its electrophoretic mobility is increased. Its density is increased. Antioxidants completely prevent these changes. These changes do not take place if transition metals in the medium are chelated with EDTA. During EC-modification as much as 40% of the LDL phosphatidylcholine is degraded to lysophosphatidylcholine by a phospholipase A2-like activity. When incubation conditions in the absence of cells were selected to favor oxidation by extending the time of incubation of LDL at low concentrations, or by increasing the Cu2+ concentration. LDL underwent changes very similar to those occurring in the presence of cells, including degradation of phosphatidylcholine. Some phospholipase activity appears to be associated with the isolated LDL used in these studies. A complex process in which endothelial cells modify LDL by mechanisms involving generation of free radicals and action of phospholipase(s) is suggested.