Gene expression profiling of Human Umbilical Vein Endothelial Cells (HUVEC) after treatment with Erg or control antisense (GeneBloc)

The endothelial transcription factor Erg (Ets Related Gene) plays an important role in homeostasis and angiogenesis by regulating many endothelial functions including survival and junction stability. Here we show that Erg regulates endothelial cell migration. Transcriptome profiling of Erg-deficient endothelial cells (EC) identified 80 genes involved in cell migration as candidate Erg targets, including regulators of the Rho GTPases. Inhibition of Erg expression in human umbilical vein endothelial cells (HUVEC) resulted in decreased migration in vitro, whilst Erg over-expression using adenovirus caused increased migration. Live-cell imaging of Erg-deficient HUVEC showed a reduction in lamellipodia, in line with decreased motility. Both actin and tubulin cytoskeletons were disrupted in Erg-deficient EC, with a dramatic increase in tubulin acetylation. Amongst the most significant microarray hit was the cytosolic histone deacetylase (HDAC)-6, a regulator of cell migration. Rescue experiments confirmed that HDAC6 mediates the Erg-dependent regulation of tubulin acetylation and actin localization. The functional role of Erg in EC was studied by gene expressing profiling using three separate HUVEC isolates treated with either control antisense or Erg-specific antisense for 24 or 48 hours.

内皮转录因子Erg（Ets Related Gene，Ets相关基因）可通过调控包括细胞存活、连接稳定性在内的多种内皮细胞功能，在内稳态与血管生成过程中发挥重要作用。本研究证实Erg可调控内皮细胞的迁移行为。对Erg缺陷型内皮细胞（Endothelial Cell，EC）的转录组分析显示，共有80个参与细胞迁移的基因被鉴定为Erg的候选靶基因，其中包括Rho GTP酶（Rho GTPases）的调控因子。在人脐静脉内皮细胞（human umbilical vein endothelial cells，HUVEC）中抑制Erg的表达会导致体外迁移能力下降，而通过腺病毒过表达Erg则可增强细胞迁移能力。对Erg缺陷型HUVEC的活细胞成像观察发现，片状伪足形成减少，这与细胞迁移能力降低的结果一致。Erg缺陷的EC中，肌动蛋白与微管蛋白细胞骨架均发生紊乱，且微管蛋白乙酰化水平显著升高。在基因芯片筛选出的显著性最高的靶基因中，便包括胞质组蛋白去乙酰化酶（histone deacetylase，HDAC）6——一种细胞迁移调控因子。挽救实验证实，HDAC6介导了Erg依赖的微管蛋白乙酰化与肌动蛋白定位调控。本研究针对Erg在内皮细胞中的功能作用展开了分析：我们对分别经对照反义寡核苷酸或Erg特异性反义寡核苷酸处理24小时或48小时的3批独立HUVEC进行了基因表达谱分析。