Brandes Ralf P, Harenkamp Sabine, Schürmann Christoph, Josipovic Ivana, Rashid Beliza, Rezende Flavia, Löwe Oliver, Moll Franziska, Epah Jeremy, Eresch Jeanette, Nayak Arnab, Kopaliani Irakli, Penski Cornelia, Mittelbronn Michel, Weissmann Norbert, Schröder Katrin
From the Institute for Cardiovascular Physiology (R.P.B., S.H., C.S., I.J., B.R., F.R., O.L., F.M., J.E., K.S.), Pharmazentrum Frankfurt (J.E.), Institute for Biochemistry II (A.N.), and Neurological Institute (Edinger Institute) (C.P., M.M.), Goethe University, Frankfurt, Germany; Department of Physiology, Medical Faculty, TU Dresden, Dresden, Germany (I.K.); Justus-Liebig Universität Giessen, Giessen, Germany (N.W.); and German Center for Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany (R.P.B., C.S., I.J., F.R., O.L., F.M., K.S.).
Arterioscler Thromb Vasc Biol. 2016 Aug;36(8):1558-65. doi: 10.1161/ATVBAHA.116.307132. Epub 2016 Jun 9.
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.
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 α-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.
NoxO1 stimulates α-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.
烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶产生的活性氧有助于血管生成和血管修复。NADPH氧化酶组装蛋白1（NoxO1）是一种促进组成型活性NADPH氧化酶组装的胞质蛋白。我们推测NoxO1也有助于血管系统中基础活性氧的形成，从而调节血管生成。
构建了NoxO1基因敲除小鼠，并在培养细胞和体内研究血管生成。与野生型动物相比，NoxO1基因敲除小鼠发育中的视网膜和股动脉结扎后的血管生成增加。球体生长试验显示，NoxO1基因敲除的肺内皮细胞（LEC）比野生型LEC具有更强的血管生成能力和更像尖端细胞的表型。通常，Notch信号通路可使内皮细胞从尖端细胞表型转变为茎细胞表型。NoxO1基因敲除的LEC在配体刺激下，由于Notch细胞内结构域释放减弱，Notch信号传导减弱。这种释放是由涉及α-分泌酶ADAM17的蛋白水解切割介导的。为了达到最大活性，ADAM17必须被氧化，NoxO1的过表达促进了这种激活模式。此外，与野生型LEC相比，NoxO1基因敲除的LEC中ADAM17的活性降低。
NoxO1可能通过活性氧介导的氧化作用刺激α-分泌酶活性。NoxO1的缺失减弱了Notch信号传导，从而促进了尖端细胞表型，导致血管生成增加。
