Lysophosphatidylcholine activates extracellular signal-regulated kinases 1/2 through reactive oxygen species in rat vascular smooth muscle cells
Lysophosphatidylcholine activates extracellular signal-regulated kinases 1/2 through reactive oxygen species in rat vascular smooth muscle cells
复制标题
DOI：
10.1161/01.atv.0000015903.02749.71
复制
发表时间：
2002-05-01
影响因子：
8.7
通讯作者：
Eguchi, S
中科院分区：
文献类型：
--
作者：
Yamakawa, T;Tanaka, S;Eguchi, S
溶血磷脂酰胆碱通过激活细胞外信号调节激酶1/2(ERK1/2)作用于血管平滑肌细胞(VSMCs)，产生促有丝分裂反应。在本研究中，我们研究了活性氧物种(ROS)在溶菌素PC刺激培养的大鼠VSMCs激活ERK1/2过程中的重要性。用LysoPC处理3分钟后，细胞内ROS增加2倍，该作用可被NADH/NADPH氧化酶抑制剂二苯基碘(DPI)阻断。抗氧化剂N-乙酰-L-半胱氨酸、谷胱甘肽单酯或α-生育酚可抑制由溶酶PC激活的ERK1/2。在VSMC株系A10中也得到了几乎相同的结果。DPI可抑制ERK1/2的激活，而DPI不能抑制ERK1/2的激活。在A10细胞中表达的FLAG标记的p47Phox在LysoPC刺激2分钟后从胞浆移位到膜上。在A10细胞中过表达显性负性p47Phox抑制了LysoPC诱导的ERK激活。溶质PC激活ROS依赖的ERK似乎涉及蛋白激酶C和RAS依赖的RAF-1的激活。DPI和NAC也能抑制溶菌素PC诱导的c-fos表达和AP-1结合活性的增强。综上所述，这些数据表明，NADH/NADPH氧化酶产生的ROS参与了LysoPC诱导的ERK1/2的激活，并随后促进了VSMC的生长。
Lysophosphatidylcholine (lysoPC) acts on vascular smooth muscle cells (VSMCs) to produce a mitogenic response through the activation of extracellular signal-regulated kinases 1/2 (ERK1/2). In the present study, we examined the importance of reactive oxygen species (ROS) in lysoPC-stimulated ERK1/2 activation in cultured rat VSMCs. Treatment with lysoPC for 3 minutes caused a 2-fold increase in intracellular ROS that was blocked by the NADH/NADPH oxidase inhibitor, diphenylene iodonium (DPI). Antioxidants, N-acetyl-L-cysteine, glutathione monoester, or a-tocopherol, inhibited ERK1/2 activation by lysoPC. Almost identical results were obtained in the VSMC line A10. Pretreatment of VSMCs with DPI but not allopurinol or potassium cyanide (KCN) abrogated the activation of ERK1/2. The Flag-tagged p47phox expressed in A10 cells was translocated from the cytosol to the membrane after 2 minutes of stimulation with lysoPC. The overexpression of dominant-negative p47phox in A10 cells suppressed lysoPC-induced ERK activation. The ROS-dependent ERK activation by lysoPC seems to involve protein kinase C- and Ras-dependent raf-1 activation. Induction of c-fos expression and enhanced AP-1 binding activity by lysoPC were also inhibited by DPI and NAC. Taken together, these data suggest that ROS generated by NADH/NADPH oxidase contribute to lysoPC-induced activation of ERK1/2 and subsequent growth promotion in VSMCs.