Tamilarasan K P, Kolluru Gopi Krishna, Rajaram Megha, Indhumathy M, Saranya R, Chatterjee Suvro
Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India.
BMC Cell Biol. 2006 Apr 4;7:17. doi: 10.1186/1471-2121-7-17.
Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in angiogenesis, we speculate a cross-talk between thalidomide and nitric oxide signaling pathway to define angiogenesis. The aim of present study is to understand the mechanistic aspects of thalidomide-mediated attenuation of angiogenesis induced by nitric oxide at the cellular level.
To study the cellular mechanism of thalidomide-mediated blocking of angiogenesis triggered by nitric oxide, we used two endothelial cell based models: 1) wound healing and 2) tube formation using ECV 304, an endothelial cell line. These cell-based models reflect pro-angiogenic events in vivo. We also studied the effects of thalidomide on nitric oxide mediated egg yolk angiogenesis. Thalidomide could block the formation of blood vessels both in absence and presence of nitric oxide. Thalidomide effects on migration of, and actin polymerization in, ECV 304 cells were studied at the single cell level using live cell imaging techniques and probes to detect nitric oxide.
Results demonstrate that thalidomide blocks nitric oxide-mediated angiogenesis in egg yolk model and also reduces the number of tubes formed in endothelial cell monolayers. We also observed that thalidomide arrests wound healing in presence and absence of nitric oxide in a dose-dependent fashion. Additionally, thalidomide promotes actin polymerization and antagonizes the formation of membrane extensions triggered by nitric oxide in endothelial cells. Experiments targeting single tube structure with thalidomide, followed by nitric oxide treatment, show that the tube structures are insensitive to thalidomide and nitric oxide. These observations suggest that thalidomide interferes with nitric oxide-induced migration of endothelial cells at the initial phase of angiogenesis before cells co-ordinate themselves to form organized tubes in endothelial cells and thereby inhibits angiogenesis.
Thalidomide exerts inhibitory effects on nitric oxide-mediated angiogenesis by altering sub-cellular actin polymerization pattern, which leads to inhibition of endothelial cell migration.
沙利度胺是一种免疫调节剂，可抑制血管生成。沙利度胺抗血管生成活性的机制尚未完全明确。由于一氧化氮参与血管生成，我们推测沙利度胺与一氧化氮信号通路之间存在相互作用以确定血管生成情况。本研究的目的是在细胞水平上了解沙利度胺介导的一氧化氮诱导的血管生成减弱的机制。
为研究沙利度胺介导的一氧化氮触发的血管生成阻断的细胞机制，我们使用了两种基于内皮细胞的模型：1）伤口愈合模型和2）使用内皮细胞系ECV 304的管形成模型。这些基于细胞的模型反映了体内的促血管生成事件。我们还研究了沙利度胺对一氧化氮介导的蛋黄血管生成的影响。无论有无一氧化氮，沙利度胺均可阻断血管形成。使用活细胞成像技术和检测一氧化氮的探针，在单细胞水平上研究了沙利度胺对ECV 304细胞迁移和肌动蛋白聚合的影响。
结果表明，沙利度胺在蛋黄模型中阻断一氧化氮介导的血管生成，并减少内皮细胞单层中形成的管的数量。我们还观察到，无论有无一氧化氮，沙利度胺均以剂量依赖性方式阻止伤口愈合。此外，沙利度胺促进肌动蛋白聚合，并拮抗一氧化氮在内皮细胞中触发的膜延伸的形成。用沙利度胺靶向单个管结构，随后进行一氧化氮处理的实验表明，管结构对沙利度胺和一氧化氮不敏感。这些观察结果表明沙利度胺在血管生成的初始阶段干扰一氧化氮诱导的内皮细胞迁移，在此之前细胞自身协调形成内皮细胞中有组织的管，从而抑制血管生成。
沙利度胺通过改变亚细胞肌动蛋白聚合模式对一氧化氮介导的血管生成发挥抑制作用，这导致内皮细胞迁移受到抑制。
