Role of lysophosphatidylcholine in the inhibition of endothelial cell motility by oxidized low density lipoprotein
Role of lysophosphatidylcholine in the inhibition of endothelial cell motility by oxidized low density lipoprotein
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DOI：
10.1172/jci118728
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发表时间：
1996-06-15
影响因子：
15.9
通讯作者：
Fox, PL
中科院分区：
文献类型：
--
作者：
Murugesan, G;Fox, PL
内皮细胞（EC）的运动是血管发育和修复所必需的。我们之前的研究表明，被过渡金属氧化的LDL几乎完全抑制体外血管EC的创面愈合迁移反应。我们现在报道了溶血磷脂酰胆碱（lysoPC），氧化LDL的脂质成分，在脂蛋白的抗迁移活性中起重要作用，纯化的1-棕榈酰溶血胆碱在12-15 μ M时具有半最大活性，在20 μ M时几乎完全抑制运动；lysoPC的抑制浓度与其在氧化LDL中的丰度一致，抑制不是由于细胞毒性，因为蛋白质合成不受影响，并且由于去除lysoPC后EC运动恢复，溶血磷脂活性依赖于脂质结构，含有1位C-16或C-18饱和脂肪酸的lysoPC具有抗迁移作用，但含有c -小于或等于14的饱和脂肪酸或多不饱和脂肪酸的lysoPC不具有抗迁移作用。对不同头组的1-棕榈酰溶脂活性进行了测定，结果表明，溶血磷脂酰肌醇的抗迁移作用强于溶血磷脂酰甘油和溶血磷脂酰胆碱，而溶血磷脂酰丝氨酸和溶血磷脂酰乙醇胺的抗迁移作用强于溶血磷脂酰胆碱。单甘油酯无活性，而溶血磷酸酯有促迁移活性，这些结果与头群大小一致，而不是电荷作为活性的关键决定因素。为了证明完整脂蛋白中的溶血磷脂具有活性，用蜂毒磷脂酶A(2) （PLA(2)）处理LDL。修饰后的脂蛋白抑制EC运动的程度与铁氧化LDL相同，并且抗迁移活性与形成的lysoPC的数量相关。为了确定氧化LDL中存在的lysoPC的抗迁移活性，用正相高效液相色谱法对氧化LDL的脂质提取物进行了分离，与lysoPC相结合的部分与总提取物的活性几乎相同，证实了lysoPC（或共洗脱脂质）是氧化LDL中的主要抗迁移分子。这些研究表明，在体外，氧化LDL中的溶磷脂限制了EC伤口愈合反应，并提示溶脂可能在体内限制剥脱性损伤后内皮细胞再生中起作用。
Endothelial cell (EC) movement is required for the development and repair of blood vessels. We have previously shown that LDL oxidized by transition metals almost completely suppressed tile wound-healing migratory response of vascular EC in vitro. We now report that lysophosphatidylcholine (lysoPC), a lipid component of oxidized LDL, has an important role in the antimigratory activity of the lipoprotein, Purified 1-palmitoyl lysoPC inhibited movement with a half-maximal activity at 12-15 mu M, and near complete inhibition at 20 mu M; the inhibitory concentration of lysoPC was consistent with its abundance in oxidized LDL, The inhibition was not due to cytotoxicity since protein synthesis was unaffected and since EC movement was restored after removal of lysoPC, Lysophospholipid activity was dependent on Lipid structure, LysoPC's containing 1-Position C-16 or C-18 saturated fatty acids were antimigratory, but those containing C-less than or equal to 14 saturated fatty acids or polyunsaturated fatty acids were not, The activity of 1-palmitoyl lysolipids with various head groups was examined, Lysophosphatidylinositol was more antimigratory than lysophosphatidylglycerol and lysophosphatidylcholine, which were more potent than lysophosphatidylserine and lysophosphatidylethanolamine. Monoglyceride was inactive while lysophosphatidate had promigratory activity, These results are consistent with head group size rather than charge as a critical determinant of activity. To show that lysophospholipids within an intact lipoprotein were active, LDL was treated with bee venom phospholipase A(2) (PLA(2)). The modified lipoprotein inhibited EC movement to the same extent as iron-oxidized LDL and antimigratory activity correlated with the amount of lysoPC formed, To determine antimigratory activity of lysoPC present in oxidized LDL, lipid extracts from oxidized LDL were fractionated by normal phase HPLC, The fraction comigrating with lysoPC had nearly the same activity as the total extract confirming that lysoPC (or a co-eluting lipid) was a major antimigratory molecule in oxidized LDL, These studies demonstrate that lysoPC in oxidized LDL limit EC wound healing responses in vitro, and suggest a possible role for lysolipids in limiting endothelial regeneration after a denuding injury in vivo.