Rodriguez Fiona, Vacaru Andrei, Overvoorde John, den Hertog Jeroen
Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Dev Biol. 2008 Dec 1;324(1):122-30. doi: 10.1016/j.ydbio.2008.09.011. Epub 2008 Sep 23.
Dep1 is a transmembrane protein-tyrosine phosphatase (PTP) that is expressed in vascular endothelial cells and has tumor suppressor activity. Mouse models with gene targeted Dep1 either show vascular defects, or do not show any defects at all. We used the zebrafish to investigate the role of Dep1 in early development. The zebrafish genome encodes two highly homologous Dep1 genes, Dep1a and Dep1b. Morpholinos specific for Dep1a and Dep1b induced defects in vasculature, resulting in defective blood circulation. However, Green Fluorescent Protein expression in fli1a::gfp1 transgenic embryos and cdh5 expression, markers of vascular endothelial cells, were normal upon Dep1a- and Dep1b-MO injection. Molecular markers indicated that arterial specification was reduced and venous markers were expanded in Dep1 morphants. Moreover, the Dep1a/Dep1b knockdowns were rescued by inhibition of Phosphatidylinositol-3 kinase (PI3K) and by expression of active Notch and Grl/Hey2. Our results suggest a model in which Dep1 acts upstream in a signaling pathway inhibiting PI3K, resulting in expression of Notch and Grl, thus regulating arterial specification in development.
Dep1是一种跨膜蛋白酪氨酸磷酸酶（PTP），在血管内皮细胞中表达并具有肿瘤抑制活性。基因靶向Dep1的小鼠模型要么表现出血管缺陷，要么根本没有任何缺陷。我们利用斑马鱼来研究Dep1在早期发育中的作用。斑马鱼基因组编码两个高度同源的Dep1基因，Dep1a和Dep1b。针对Dep1a和Dep1b的吗啉代寡核苷酸诱导血管系统缺陷，导致血液循环不良。然而，在注射Dep1a-和Dep1b-MO后，fli1a::gfp1转基因胚胎中的绿色荧光蛋白表达以及血管内皮细胞标记物cdh5的表达均正常。分子标记表明，Dep1 morphants中动脉特化减少，静脉标记物增加。此外，通过抑制磷脂酰肌醇-3激酶（PI3K）以及表达活性Notch和Grl/Hey2可挽救Dep1a/Dep1b基因敲低。我们的结果提示了一种模型，其中Dep1在抑制PI3K的信号通路中起上游作用，导致Notch和Grl的表达，从而在发育过程中调节动脉特化。
