Forooghian Farzin, Das Bikul
Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada.
Am J Ophthalmol. 2007 Nov;144(5):761-8. doi: 10.1016/j.ajo.2007.07.022. Epub 2007 Sep 17.
To compare the in vitro anti-angiogenic effects of inhibiting vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-alpha (HIF-1alpha) using ribonucleic acid (RNA) interference (RNAi).
Laboratory investigation.
VEGF or HIF-1alpha was antagonized in human retinal pigment epithelial (RPE) cells using RNAi, and then cells were cultured under hypoxia. Angiogenic proteins secreted into the media were measured using enzyme-linked immunosorbent assay. Media from hypoxic RPE cells was used to grow human umbilical vein endothelial cells (HUVECs). Capillary tube formation by HUVECs was quantified and compared to assess the effectiveness of angiogenesis.
RNAi targeting VEGF caused a significant decrease in VEGF in addition to several other clinically important angiogenic factors, including angiogenin, interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and tumor growth factor beta(1) (TGF-beta(1)). Although HIF-1alpha RNAi reduced the production of VEGF, angiogenin, and TGF-beta(1), we observed an increase in the levels of several other angiogenic factors like IL-6, IL-8, and MCP-1. RNAi of VEGF and HIF-1alpha was effective in inhibiting angiogenesis, although the effect was more pronounced for VEGF RNAi.
RNAi of VEGF and HIF-1alpha may have therapeutic potential in ischemic retinal diseases like diabetic retinopathy. Targeting VEGF seems to have the advantage of decreasing the production of several clinically important angiogenic factors, thereby effectively inhibiting angiogenesis. Antagonism of HIF-1alpha may lead to the overactivation of alternate transcription factors and their respective gene products, leading to less effective inhibition of angiogenesis.
使用核糖核酸（RNA）干扰（RNAi）比较抑制血管内皮生长因子（VEGF）和缺氧诱导因子1α（HIF-1α）的体外抗血管生成作用。
实验室研究。
使用RNAi在人视网膜色素上皮（RPE）细胞中拮抗VEGF或HIF-1α，然后在缺氧条件下培养细胞。使用酶联免疫吸附测定法测量分泌到培养基中的血管生成蛋白。来自缺氧RPE细胞的培养基用于培养人脐静脉内皮细胞（HUVEC）。对HUVEC形成的毛细管进行定量并比较，以评估血管生成的有效性。
靶向VEGF的RNAi除了导致VEGF显著减少外，还使其他几种临床上重要的血管生成因子显著减少，包括血管生成素、白细胞介素-6（IL-6）、白细胞介素-8（IL-8）、单核细胞趋化蛋白-1（MCP-1）和肿瘤生长因子β(1)（TGF-β(1)）。虽然HIF-1α RNAi降低了VEGF、血管生成素和TGF-β(1)的产生，但我们观察到其他几种血管生成因子如IL-6、IL-8和MCP-1的水平有所增加。VEGF和HIF-1α的RNAi在抑制血管生成方面是有效的，尽管VEGF RNAi的效果更明显。
VEGF和HIF-1α的RNAi在糖尿病视网膜病变等缺血性视网膜疾病中可能具有治疗潜力。靶向VEGF似乎具有减少几种临床上重要的血管生成因子产生的优势，从而有效抑制血管生成。拮抗HIF-1α可能导致替代转录因子及其各自基因产物的过度激活，从而导致对血管生成的抑制效果较差。
