Minami Takashi, Kuivenhoven Jan Albert, Evans Valerie, Kodama Tatsuhiko, Rosenberg Robert D, Aird William C
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro Tokyo, 153-8904.
Arterioscler Thromb Vasc Biol. 2003 Nov 1;23(11):2041-7. doi: 10.1161/01.ATV.0000089326.63053.9A. Epub 2003 Jul 31.
Tie-2 is an endothelial cell-specific receptor tyrosine kinase that is involved in the remodeling of blood vessels and angiogenesis. Our goal was to characterize Tie-2 promoter function as a means of providing insight into the mechanisms of endothelial cell-specific gene regulation.
When targeted to the Hprt locus of mice, a small Tie-2 promoter fragment (containing a 300-bp intronic enhancer coupled upstream to a 423-bp core promoter) (T-short) directed widespread endothelial cell expression in vivo. The T-short promoter contains 2 clusters of Ets sites, one in the first exon, the other in the intronic enhancer. In cultured endothelial cells, a combined mutation of the Ets motifs resulted in a significant reduction in promoter activity. Consistent with these results, the same Ets mutations resulted in a loss of detectable expression of the T-short promoter in all vascular beds with the notable exception of the brain.
These results suggest that the T-short promoter contains information for widespread expression in the vascular tree, Ets sites are necessary for in vivo promoter activity, and the shorter Tie-2 fragment may be useful as a tool to direct heterologous gene expression within the intact endothelium.
Tie-2是一种内皮细胞特异性受体酪氨酸激酶，参与血管重塑和血管生成。我们的目标是对Tie-2启动子功能进行表征，以此深入了解内皮细胞特异性基因调控机制。
当靶向小鼠的Hprt基因座时，一个小的Tie-2启动子片段（包含一个与上游423 bp核心启动子相连的300 bp内含子增强子）（T-short）在体内引导广泛的内皮细胞表达。T-short启动子包含2个Ets位点簇，一个在第一个外显子中，另一个在内含子增强子中。在培养的内皮细胞中，Ets基序的联合突变导致启动子活性显著降低。与这些结果一致，相同的Ets突变导致T-short启动子在除脑以外的所有血管床中均失去可检测到的表达。
这些结果表明，T-short启动子包含在血管树中广泛表达的信息，Ets位点对于体内启动子活性是必需的，较短的Tie-2片段可能作为在完整内皮中指导异源基因表达的工具。
