Mechanisms of PAI-1 Induced Anti-Angiogenesis

PAI-1 诱导抗血管生成的机制

• 批准号: 6610017
• 负责人: MARY Jo MULLIGAN-KEHOE
• 金额: $ 27.65万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6610017
• 关键词: angiogenesis; angiostatins; animal tissue; apoptosis; atherosclerotic plaque; cell proliferation; focal adhesion kinase; growth factor receptors; heparan sulfate; human tissue; matrigel; metalloendopeptidases; plasmin; plasminogen activator; plasminogen activator inhibitors; protein protein interaction; recombinant proteins; tissue /cell culture; vascular endothelial growth factors; vascular endothelium

DESCRIPTION (provided by applicant): Endothelial cells lining the vascular wall are normally maintained in a differentiated, quiescent state by anti-angiogenic molecules. Pro-angiogneic molecules destabilize the quiescent endothelium into migratory, proliferative endothelial cells that form new capillary blood vessels. The steady turn over rate of the vascular endothelium is maintained by a tightly controlled balance of pro- and anti-angiogenic molecules that have cell survival and death functions, respectively. A shift in the balance can alter the turn over rate of the endothetium and disrupt vascular homeostasis. It has been shown that vascular endothelial growth factor (VEGF) has a role in atherosclerotic plaque development. This is supported by studies which show that angiogenesis is associated with increases in plasmin and metalloproteinase activity which increases plaque susceptibility to acute rupture or plaque destabilization. Several animal studies have shown a reduction in atherosclerotic plaque neovascularization and plaque growth after treatment with angiogenesis inhibitors. Plasminogen activator inhibitor-1 (PAl-1) is over expressed in the intimal layer in the atherosclerotic vessel wall in human coronary artery disease. This has led to one hypothesis that PAl-1 expression is a means of controlling localized plasminogen activators that contribute to extracellular matrix degradation and smooth muscle cell migration. We have constructed recombinant truncated PAl-1 (rPAI-1) proteins to examine the anti-angiogenic activity of PAl-1 in "inactive" conformations (absence of reactive center loop). One rPAI-1 protein, rPAI-123, has potent anti-angiogenic activity. The activity of rPAI-123 induces cleavage of plasmin into angiostatin and inhibits the bioavailability of VEGF. In this study, we will utilize rPAI-123 to: Aim I: Clarify the rPAI-123 interactions that induce cleavage of plasmin into angiostatin; Aim II: Determine if rPAI-123 inhibits VEGF release from heparan sulfate; and Aim Ill: Define the anti-angiogenic/pro-apoptotic signaling pathways in rPAI-123 treated aortic endothelial cells. Due to the potent anti-angiogenic activity of rPAI-123 protein, it may ultimately play a useful role in the treatment of diiseases characterized by excessive angiogenesis, such as progression and stabilization of atherosclerotic plaques, diabetic retinopathy, and certain types of cancer.

描述（由申请人提供）： 血管壁内衬的内皮细胞通常通过抗血管生成分子维持在分化的静止状态。促血管生成分子使静止的内皮不稳定，形成迁移、增殖的内皮细胞，从而形成新的毛细血管。血管内皮的稳定周转率是通过分别具有细胞存活和死亡功能的促血管生成分子和抗血管生成分子的严格控制的平衡来维持的。平衡的改变会改变内皮细胞的更新率并破坏血管稳态。研究表明，血管内皮生长因子（VEGF）在动脉粥样硬化斑块的形成中发挥作用。研究表明，血管生成与纤溶酶和金属蛋白酶活性增加有关，从而增加斑块对急性破裂或斑块不稳定的敏感性。几项动物研究表明，用血管生成抑制剂治疗后，动脉粥样硬化斑块新生血管形成和斑块生长减少。纤溶酶原激活剂抑制剂-1(PA1-1)在人冠状动脉疾病的动脉粥样硬化血管壁的内膜层中过度表达。这导致了一种假设：PA1-1表达是控制局部纤溶酶原激活剂的一种手段，该激活剂有助于细胞外基质降解和平滑肌细胞迁移。我们构建了重组截短的PAI-1(rPAI-1)蛋白以检查“非活性”构象(不存在反应性中心环)的PAl-1的抗血管生成活性。一种 rPAI-1 蛋白 rPAI-123 具有有效的抗血管生成活性。 rPAI-123 的活性诱导纤溶酶裂解为血管抑制素并抑制 VEGF 的生物利用度。在本研究中，我们将利用 rPAI-123 来： 目标 I：阐明 rPAI-123 诱导纤溶酶裂解为血管抑制素的相互作用；目标 II：确定 rPAI-123 是否抑制硫酸乙酰肝素释放 VEGF；目标III：定义rPAI-123处理的主动脉内皮细胞中的抗血管生成/促凋亡信号传导途径。由于rPAI-123蛋白具有强大的抗血管生成活性，它最终可能在治疗以过度血管生成为特征的疾病中发挥有用的作用，例如动脉粥样硬化斑块的进展和稳定、糖尿病视网膜病变和某些类型的癌症。