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，我们研究了依赖血管内皮生长因子的新生血管形成的调控机制。整合素αVbeta3、αVbeta5以及这些配体、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，低氧刺激通过刺激血管内皮生长因子诱导这些整合蛋白的表达，TSP-1和OPN在低氧视网膜中表达上调。这表明抗TSP-1或OPN抗体在阻断新生血管方面是有效的。我们发现血管紧张素II(AII)通过AT-1受体和PKC依赖地上调视网膜内皮细胞中血管内皮生长因子受体、KDR的表达。AII的这些作用诱导依赖于血管内皮生长因子的新生血管形成。AII还诱导视网膜周细胞表达血管内皮生长因子，我们检测到转录因子AP-1介导了这一过程。这些数据提示，血管紧张素转换酶抑制剂或血管紧张素转换酶1受体抑制剂的药物治疗以及AP-1的调节可能是治疗糖尿病视网膜病变等缺血性视网膜血管生成疾病的有效方法。我们还发现了手术切除的脉络膜新生血管膜和糖尿病硬性渗出物中血管内皮生长因子的重要性。细胞因子包括肿瘤坏死因子-α或白介素1-β诱导视网膜色素上皮细胞表达血管内皮生长因子，说明细胞因子在视网膜色素上皮细胞损伤中的重要作用。黄斑变性新生血管的形成。曲尼司特最初是作为一种抗过敏药物开发的，通过抑制视网膜内皮细胞中依赖于PKC的信号转导，抑制了血管内皮生长因子诱导的血管生成和血管通透性。曲尼司特可能被证明是一种有效的抑制缺血性视网膜疾病视网膜新生血管的药物。我们得出结论，控制这些因素是治疗缺血性视网膜新生血管疾病的有效方法。

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.