Nitric oxide regulates angiogenesis through a functional switch involving thrombospondin-1
Nitric oxide regulates angiogenesis through a functional switch involving thrombospondin-1
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DOI：
10.1073/pnas.0502979102
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发表时间：
2005-09-13
影响因子：
11.1
通讯作者：
Wink, DA
中科院分区：
文献类型：
--
作者：
Ridnour, LA;Isenberg, JS;Wink, DA
一氧化氮（NO）供体在体外可刺激和抑制内皮细胞的增殖、迁移和分化，在体内可刺激和抑制血管生成。最近，我们已经显示了NO调节肿瘤细胞中p53-Ser-15 P、磷酸化细胞外信号调节激酶（pERK）和缺氧诱导因子Ia的不同阈值。由于这些信号通路也促进内皮细胞的生长和存活，我们研究了它们在静脉内皮细胞的血管生成反应和肌肉外植体的血管生长中的作用引起的NO。另外一种参与血管生成调节的蛋白质是血小板反应蛋白-1（TSP 1），一种已知影响内皮细胞粘附、迁移和增殖的基质细胞糖蛋白。在这里，我们证明了一个三相调节TSP 1介导的一个缓慢和长期的释放NO依赖于ERK磷酸化。在5%血清条件下，NO供体（0.1- 1，000 μ M）暴露24小时介导TSP 1蛋白表达的三相反应：0.1 μ M时降低，100 μ M时反弹，1，000 μ M时再次降低。在相同条件下，我们观察到P53磷酸化的剂量依赖性增加和pERK和丝裂原活化蛋白激酶磷酸酶-1的反向双相反应。低剂量NO对内皮细胞的生长刺激活性和对TSP 1表达的抑制均依赖于ERK。相反，外源性TSP 1抑制NO介导的pERK。这些结果表明，剂量依赖性的正反馈和负反馈回路之间存在NO和TSP 1。通过ERK丝裂原活化蛋白激酶途径的正反馈限制TSP 1表达可能有助于在低剂量NO下切换到促血管生成状态。
Nitric oxide (NO) donors have been shown to stimulate and inhibit the proliferation, migration, and differentiation of endothelial cells in vitro and angiogenesis in vivo. Recently, we have shown distinct thresholds for NO to regulate p53-Ser-15P, phosphorylated extracellular signal-regulated kinase (pERK), and hypoxia inducible factor la in tumor cells. Because these signaling pathways also promote the growth and survival of endothelial cells, we examined their roles in angiogenic responses of venous endothelial cells and vascular outgrowth of muscle explants elicited by NO. An additional protein involved in the regulation of angiogenesis is thrombospondin-1 (TSP1), a matricellular glycoprotein known to influence adhesion, migration, and proliferation of endothelial cells. Here we demonstrate a triphasic regulation of TSP1 mediated by a slow and prolonged release of NO that depends on ERK phosphorylation. Under conditions of 5% serum, a 24-h exposure of NO donor (0.1-1,000 mu M) mediated a triphasic response in the expression of TSP1 protein: decreasing at 0.1 mu M, rebounding at 100 mu M, and decreasing again at 1,000 mu M. Under the same conditions, we observed a dose-dependent increase in P53 phosphorylation and inverse biphasic responses of pERK and mitogen-activated protein kinase phosphatase-1. Both the growth-stimulating activity of low-dose NO for endothelial cells and suppression of TSP1 expression were ERK-dependent. Conversely, exogenous TSP1 suppressed No-mediated pERK. These results suggest that dose-dependent positive- and negative-feed back loops exist between NO and TSP1. Limiting TSP1 expression by positive feedback through the ERK mitogen-activated protein kinase pathway may facilitate switching to a proangiogenic state at low doses of NO.