NADPH oxidase activity selectively modulates vascular endothelial growth factor signaling pathways.
Vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) play critical roles in vascular physiology and pathophysiology. We have demonstrated previously that NADPH oxidase-derived ROS are required for VEGF-mediated migration and proliferation of endothelial cells. The goal of this study was to determine the extent to which VEGF signaling is coupled to NADPH oxidase activity. Human umbilical vein endothelial cells and/or human coronary artery endothelial cells were transfected with short interfering RNA against the p47(phox) subunit of NADPH oxidase, treated in the absence or presence of VEGF, and assayed for signaling, gene expression, and function. We show that NADPH oxidase activity is required for VEGF activation of phosphoinositide 3-kinase-Akt-forkhead, and p38 MAPK, but not ERK1/2 or JNK. The permissive role of NADPH oxidase on phosphoinositide 3-kinase-Akt-forkhead signaling is mediated at post-VEGF receptor levels and involves the nonreceptor tyrosine kinase Src. DNA microarrays revealed the existence of two distinct classes of VEGF-responsive genes, one that is ROS-dependent and another that is independent of ROS levels. VEGF-induced, thrombomodulin-dependent activation of protein C was dependent on NADPH oxidase activity, whereas VEGF-induced decay-accelerating factor-mediated protection of endothelial cells against complement-mediated lysis was not. Taken together, these findings suggest that NADPH oxidase-derived ROS selectively modulate some but not all the effects of VEGF on endothelial cell phenotypes.
Abid
Md Ruhul
MR
Division of Molecular and Vascular Medicine, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA. rabid@bidmc.harvard.edu
Spokes
Katherine C
KC
Shih
Shou-Ching
SC
Aird
William C
WC
D002478:Cells, Cultured; D005786:Gene Expression Regulation; D006801:Humans; D008954:Models, Biological; D019255:NADPH Oxidases / Q000378:metabolism*; D010084:Oxidation-Reduction; D010641:Phenotype; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011486:Protein C / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species; D015398:Signal Transduction; D018180:Thrombomodulin / Q000378:metabolism; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D011486:Protein C; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D018180:Thrombomodulin; D042461:Vascular Endothelial Growth Factor A; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases