Guo Yan-Lin, Wang Shujie, Cao Dian J, Colman Robert W
Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
J Cell Biochem. 2003 Jun 1;89(3):622-32. doi: 10.1002/jcb.10536.
We previously reported that cleaved high molecular weight kininogen (HKa) and its domain 5 (D5) inhibit critical steps required for angiogenesis and in vivo neovascularization (Colman et al. 2000: Blood 95:543-550). We have further shown that D5 is able to induce apoptosis of endothelial cells, which may represent a critical part of the anti-angiogenic activity of HKa and D5 (Guo et al. 2001: Arterioscler Thromb Vasc Biol 21:1427-1433). In this study, we demonstrate that HKa- and D5-induced apoptosis is closely correlated with their anti-adhesive effect. An important new finding is that the apoptotic activity of HKa and D5 is highly regulated by their interactions with different extracellular matrix (ECM) proteins. HKa inhibited cell adhesion to vitronectin (Vn, 90%) and gelatin (Gel) (40%), but it had no apparent effect on cell adhesion to fibronectin (Fn). D5 showed a similar pattern on cell adhesion but was less potent than HKa. HKa induced apoptosis of endothelial cells grown on Vn and Gel but not cells grown on Fn which closely parallels with its anti-adhesive potency. Further results revealed that the anti-adhesive effect and the apoptotic effect of HKa are associated with its ability to inhibit phosphorylation of focal adhesion kinase (FAK) and paxillin, two important signal molecules required for cell adhesion and cell viability. We conclude that the anti-adhesive activity of HKa and D5 is responsible for their apoptotic effect and that Vn is likely an ECM component that mediates the effect of HKa and D5.
我们先前报道，裂解的高分子量激肽原（HKa）及其结构域5（D5）可抑制血管生成和体内新血管形成所需的关键步骤（科尔曼等人，2000年：《血液》95:543 - 550）。我们进一步表明，D5能够诱导内皮细胞凋亡，这可能是HKa和D5抗血管生成活性的关键部分（郭等人，2001年：《动脉硬化血栓与血管生物学》21:1427 - 1433）。在本研究中，我们证明HKa和D5诱导的凋亡与其抗黏附作用密切相关。一个重要的新发现是，HKa和D5的凋亡活性受其与不同细胞外基质（ECM）蛋白相互作用的高度调控。HKa抑制细胞与玻连蛋白（Vn，90%）和明胶（Gel）（40%）的黏附，但对细胞与纤连蛋白（Fn）的黏附无明显影响。D5在细胞黏附方面表现出类似模式，但效力低于HKa。HKa诱导在Vn和Gel上生长的内皮细胞凋亡，但不诱导在Fn上生长的细胞凋亡，这与其抗黏附效力密切平行。进一步结果显示，HKa的抗黏附作用和凋亡作用与其抑制黏着斑激酶（FAK）和桩蛋白磷酸化的能力相关，这两种是细胞黏附和细胞活力所需的重要信号分子。我们得出结论，HKa和D5的抗黏附活性是其凋亡作用的原因，并且Vn可能是介导HKa和D5作用的一种ECM成分。
