Activation of actin polymerization by phosphatidic acid derived from phosphatidylcholine in IIC9 fibroblasts.
Activation of actin polymerization by phosphatidic acid derived from phosphatidylcholine in IIC9 fibroblasts.
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DOI：
10.1083/jcb.123.6.1789
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发表时间：
1993-12
期刊：
影响因子：
--
通讯作者：
Exton JH
中科院分区：
文献类型：
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作者：
Ha KS;Exton JH
α-凝血酶诱导IIC 9成纤维细胞的细胞形态从半圆形变为细长形，伴随着应力纤维的增加。用来自色褐链霉菌的磷脂酶D（PLD）和外源性磷脂酸（PA）孵育细胞引起类似的形态学变化，而血小板衍生生长因子（PDGF）和佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）诱导不同的变化，例如，破坏应力纤维和细胞变圆。α-凝血酶、PDGF和外源性PLD使PA增加20- 40%，PMA产生较小的增加。α-凝血酶和外源性PLD产生的丝状肌动蛋白（F-肌动蛋白），持续至少60分钟的量迅速增加。然而，PDGF产生的F-肌动蛋白在1分钟和PMA的瞬时增加没有引起显着的变化。除了50微克/毫升外，二辛酰甘油无效。从蜡状芽孢杆菌磷脂酶C，增加二酰基甘油（DAG），但不PA，没有改变F-肌动蛋白含量。蛋白激酶C（PKC）的下调并不阻断α-凝血酶诱导的肌动蛋白聚合。H-7也是无效的。外源性PA激活肌动蛋白聚合，在0.01微克/毫升时具有显著作用，在1微克/毫升时最大增加。没有其他磷脂测试，包括聚磷酸肌醇，显着激活肌动蛋白聚合。PDGF部分抑制PA诱导的肌动蛋白聚合后，在1分钟的初始增加。PMA完全或大部分阻断PA或PLD诱导的肌动蛋白聚合。这些结果表明，PC衍生的PA，而不是DAG或PKC，激活IIC 9成纤维细胞中的肌动蛋白聚合，并表明PDGF和PMA对PA诱导的肌动蛋白聚合具有抑制作用。
alpha-Thrombin induced a change in the cell morphology of IIC9 fibroblasts from a semiround to an elongated form, accompanied by an increase in stress fibers. Incubation of the cells with phospholipase D (PLD) from Streptomyces chromofuscus and exogenous phosphatidic acid (PA) caused similar morphological changes, whereas platelet-derived growth factor (PDGF) and phorbol 12-myristate 13-acetate (PMA) induced different changes, e.g., disruption of stress fibers and cell rounding. alpha-Thrombin, PDGF, and exogenous PLD increased PA by 20-40%, and PMA produced a smaller increase. alpha-Thrombin and exogenous PLD produced rapid increases in the amount of filamentous actin (F-actin) that were sustained for at least 60 min. However, PDGF produced a transient increase of F-actin at 1 min and PMA caused no significant change. Dioctanoylglycerol was ineffective except at 50 micrograms/ml. Phospholipase C from Bacillus cereus, which increased diacylglycerol (DAG) but not PA, did not change F-actin content. Down-regulation of protein kinase C (PKC) did not block actin polymerization induced by alpha-thrombin. H-7 was also ineffective. Exogenous PA activated actin polymerization with a significant effect at 0.01 microgram/ml and a maximal increase at 1 microgram/ml. No other phospholipids tested, including polyphosphoinositides, significantly activated actin polymerization. PDGF partially inhibited PA-induced actin polymerization after an initial increase at 1 min. PMA completely or largely blocked actin polymerization induced by PA or PLD. These results show that PC-derived PA, but not DAG or PKC, activates actin polymerization in IIC9 fibroblasts, and indicate that PDGF and PMA have inhibitory effects on PA-induced actin polymerization.