Development of gene therapy for retinal neovascular disorders by controlling expression of VEGF

为了建立视网膜新生血管疾病的基因治疗，我们研究了vegf依赖性新生血管的调控机制。整合素alphaVbeta3， alphaVbeta5和这些配体，血栓反应蛋白-1 （TSP-1）和骨桥蛋白（OPN）被认为是血管生成的关键因素。我们在视网膜内皮细胞中发现，缺氧刺激通过VEGF刺激诱导这些整合素，并且在缺氧视网膜中TSP-1和OPN上调。这表明针对TSP-1或OPN的抗体可有效阻断新生血管。我们发现血管紧张素II （Angiotensin II， AII）通过AT-1受体和pkc依赖性上调视网膜内皮细胞中VEGF受体、KDR的表达。AII的这些作用诱导vegf依赖性新生血管形成。AII还能诱导视网膜周细胞中VEGF的表达，我们检测到转录因子AP-1介导了这一过程。这些数据表明，ACE抑制剂或AT-1受体抑制剂的药物治疗和AP-1的调节可能是缺血性视网膜血管生成疾病（如糖尿病视网膜病变）的有效治疗方法。我们还发现VEGF在手术切除脉络膜新生血管膜和糖尿病硬渗出物中的重要性。细胞因子，包括tnf - α或il -1 β诱导VEGF在视网膜色素上皮细胞中的表达，这表明细胞因子在视网膜色素上皮细胞中的重要性。黄斑变性中新生血管的形成。曲那司特最初是作为抗过敏药物开发的，它通过抑制视网膜内皮细胞中pkc依赖的信号转导来抑制vegf诱导的血管生成和血管渗透性。曲尼司特可能被证明是一种有效的抑制剂，以防止缺血性视网膜疾病的视网膜新生血管。我们的结论是，控制这些因素是有用的治疗缺血性视网膜新生血管疾病。

To establish the gene therapy for retinal neovascular disorders, we have examined the regulatory mechanism of VEGF-dependent neovascularization.Integlin alphaVbeta3, alphaVbeta5, and these ligans, thrombospondin-1 (TSP-1) and osteopontin (OPN) are considered to be key factors in angiogenesis. We found in retinal endothelial cells that hypoxic stimulation induces these integlins Through VEGF stimulation and, TSP-1 and OPN are upregulated in hypoxic retina. This shows that antibodies for TSP-1 or OPN are effective in blocking neovascularization. We found Angiotensin II (AII) upregulates VEGF receptor, KDR expression through AT-1 receptor and PKC-dependently in retinal endothelial cells. These effect of AII induces VEGF-dependent neovascularization. AII also induces VEGF expression in retinal pericytes and we detected transcriptional factor AP-1 mediates that. These data suggest a possibility that medication of ACE inhibitor or AT-1 receptor inhibitor, and regulation of AP-1 might be effective therapies for ischemic retinal angiogenic deseases such as diabetic retinopathy.We also found the importance of VEGF in surgically excised choroidal neovascular membranes and diabetic hard exudates. Cytokines, including TNF-alpha or IL-1beta induced the expression of VEGF in retinal pigment epithelial cells, and that shows the importance of cytokines in the. formation of neovascularization in macular degeneration.Tranilast, first developed as an anti-allergic drug, inhibited VEGF-induced angiogenesis and vasopermeability through suppression of PKC-dependent signal transduction in retinal endothelial cells. Tranilast might prove an effective inhibitor to prevent retinal neovascularization in ischemic retinal diseases.We concluded that controling these factors is useful as a therapy for ischemic retinal neovascular disorders.