The Cytosolic NADPH Oxidase Subunit NoxO1 Promotes an Endothelial Stalk Cell Phenotype
The Cytosolic NADPH Oxidase Subunit NoxO1 Promotes an Endothelial Stalk Cell Phenotype
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DOI：
10.1161/atvbaha.116.307132
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发表时间：
2016-08-01
影响因子：
8.7
通讯作者：
Schroeder, Katrin
中科院分区：
文献类型：
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作者：
Brandes, Ralf P.;Harenkamp, Sabine;Schroeder, Katrin
目的研究烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶产生的活性氧在血管新生和血管修复中的作用。NADPH氧化酶组织者1（NoxO 1）是促进组成型活性NADPH氧化酶组装的胞质蛋白。我们推测，NoxO 1也有助于基础活性氧在血管系统中的形成，从而调节血管生成。方法和结果产生了一个NoxO 1基因敲除小鼠，并在培养的细胞和体内血管生成进行了研究。与野生型动物相比，NoxO 1（-/-）中发育中的视网膜和股动脉结扎后的血管生成增加。球体生长分析显示NoxO 1（-/-）肺内皮细胞（LEC）的血管生成能力更强，比野生型LEC更像尖端细胞的表型。通常通过Notch途径的信号传导将内皮细胞从尖端转变为柄细胞表型。NoxO 1（-/-）LEC表现出减弱的Notch信号传导，这是配体刺激时Notch胞内结构域释放减弱的结果。这种释放是介导的蛋白水解裂解涉及的-分泌酶ADAM 17。为了获得最大的活性，ADAM 17必须被氧化，NoxO 1的过表达促进了这种激活模式。结论NoxO 1可能通过活性氧介导的氧化作用刺激β-分泌酶活性。NoxO 1的缺失减弱Notch信号传导，从而促进尖端细胞表型，导致血管生成增加。
Objective Reactive oxygen species generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases contribute to angiogenesis and vascular repair. NADPH oxidase organizer 1 (NoxO1) is a cytosolic protein facilitating assembly of constitutively active NADPH oxidases. We speculate that NoxO1 also contributes to basal reactive oxygen species formation in the vascular system and thus modulates angiogenesis.Approach and Results A NoxO1 knockout mouse was generated, and angiogenesis was studied in cultured cells and in vivo. Angiogenesis of the developing retina and after femoral artery ligation was increased in NoxO1(-/-) when compared with wild-type animals. Spheroid outgrowth assays revealed greater angiogenic capacity of NoxO1(-/-) lung endothelial cells (LECs) and a more tip-cell-like phenotype than wild-type LECs. Usually signaling by the Notch pathway switches endothelial cells from a tip into a stalk cell phenotype. NoxO1(-/-) LECs exhibited attenuated Notch signaling as a consequence of an attenuated release of the Notch intracellular domain on ligand stimulation. This release is mediated by proteolytic cleavage involving the -secretase ADAM17. For maximal activity, ADAM17 has to be oxidized, and overexpression of NoxO1 promoted this mode of activation. Moreover, the activity of ADAM17 was reduced in NoxO1(-/-) LECs when compared with wild-type LECs.Conclusions NoxO1 stimulates -secretase activity probably through reactive oxygen species-mediated oxidation. Deletion of NoxO1 attenuates Notch signaling and thereby promotes a tip-cell phenotype that results in increased angiogenesis.