miR-200b 靶向 Ets-1 并受低氧下调,从而诱导内皮细胞的血管生成反应。
miR-200b targets Ets-1 and is down-regulated by hypoxia to induce angiogenic response of endothelial cells.
机构信息
Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
出版信息
J Biol Chem. 2011 Jan 21;286(3):2047-56. doi: 10.1074/jbc.M110.158790. Epub 2010 Nov 16.
The miR-200 family plays a crucial role in epithelial to mesenchymal transition via controlling cell migration and polarity. We hypothesized that miR-200b, one miR-200 family member, could regulate angiogenic responses via modulating endothelial cell migration. Delivery of the miR-200b mimic in human microvascular endothelial cells (HMECs) suppressed the angiogenic response, whereas miR-200b-depleted HMECs exhibited elevated angiogenesis in vitro, as evidenced by Matrigel® tube formation and cell migration. Using in silico studies, miR target reporter assay, and Western blot analysis revealed that v-ets erythroblastosis virus E26 oncogene homolog 1 (Ets-1), a crucial angiogenesis-related transcription factor, serves as a novel direct target of miR-200b. Knocking down endogenous Ets-1 simulated an anti-angiogenic response of the miR-200b mimic-transfected cells. Certain Ets-1-associated genes, namely matrix metalloproteinase 1 and vascular endothelial growth factor receptor 2, were negatively regulated by miR-200b. Overexpression of Ets-1 rescued miR-200b-dependent impairment in angiogenic response and suppression of Ets-1-associated gene expression. Both hypoxia as well as HIF-1α stabilization inhibited miR-200b expression and elevated Ets-1 expression. Experiments to identify how miR-200b modulates angiogenesis under a low oxygen environment illustrated that hypoxia-induced miR-200b down-regulation de-repressed Ets-1 expression to promote angiogenesis. This study provides the first evidence that hypoxia-sensitive miR-200b is involved in induction of angiogenesis via directly targeting Ets-1 in HMECs.
miR-200 家族通过控制细胞迁移和极性在上皮间质转化中发挥关键作用。我们假设 miR-200 家族成员之一 miR-200b 通过调节内皮细胞迁移来调节血管生成反应。在人微血管内皮细胞(HMEC)中递送 miR-200b 模拟物可抑制血管生成反应,而 miR-200b 耗尽的 HMEC 表现出体外血管生成增加,这体现在 Matrigel®管形成和细胞迁移中。通过计算机研究、miR 靶标报告测定和 Western blot 分析表明,v-ets 红细胞生成病毒 E26 癌基因同源物 1(Ets-1),一种关键的血管生成相关转录因子,作为 miR-200b 的新型直接靶标。敲低内源性 Ets-1 模拟了 miR-200b 模拟物转染细胞的抗血管生成反应。某些 Ets-1 相关基因,即基质金属蛋白酶 1 和血管内皮生长因子受体 2,受 miR-200b 的负调控。Ets-1 的过表达挽救了 miR-200b 依赖性血管生成反应损伤和抑制 Ets-1 相关基因表达。缺氧和 HIF-1α 稳定均抑制 miR-200b 的表达并增加 Ets-1 的表达。鉴定 miR-200b 在低氧环境下如何调节血管生成的实验表明,缺氧诱导的 miR-200b 下调去抑制 Ets-1 的表达以促进血管生成。本研究首次证明,缺氧敏感的 miR-200b 通过直接靶向 HMEC 中的 Ets-1 参与诱导血管生成。