title: Pigment epithelium-derived factor (PEDF) blocks angiotensin II signaling in endothelial cells via suppression of NADPH oxidase: a novel anti-oxidative mechanism of PEDF.
abstract: Angiotensin II (Ang II), the dominant effector of the renin-angiotensin system, regulates numerous inflammatory-proliferative responses in vascular wall cells and is thus involved in atherosclerosis. We have previously shown that pigment epithelium-derived factor (PEDF) inhibits advanced glycation end-product-induced pericyte apoptosis, thereby exerting beneficial effects on diabetic retinopathy. However, a role for PEDF in vascular inflammation and atherosclerosis remains to be elucidated. In this study, we have examined whether PEDF inhibits the Ang-II-induced endothelial cell (EC) activation in vitro and the way that it might achieve this effect. Ang II significantly induced redox-sensitive transcriptional factor NF-kappaB activation and subsequent monocyte chemoattractant protein-1 expression in human umbilical vein ECs (HUVEC), both of which were completely inhibited by PEDF or the anti-oxidant N-acetylcysteine. PEDF or diphenylene iodonium, an inhibitor of NADPH oxidase, inhibited Ang-II-induced intracellular reactive oxygen species (ROS) generation in HUVEC. Furthermore, PEDF inhibited Ang-II-induced up-regulation of mRNA levels of p22phox, Nox4, and gp91phox/Nox2, which are membrane components of NADPH oxidase, and its enzymatic activity in HUVEC. Antisense, but not sense, DNAs against p22phox, Nox4, or gp91phox/Nox2 were found significantly to inhibit Ang-II-induced ROS generation in HUVEC. These results demonstrate that PEDF inhibits Ang-II-induced EC activation by suppressing NADPH-oxidase-mediated ROS generation and that PEDF may play a protective role in the development and progression of atherosclerosis.
authors.affiliation: Department of Internal Medicine III, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan. shoichi@med.kurume-u.ac.jp
authors.forename: Sho-Ichi
authors.initials: S
authors.lastname: Yamagishi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakamura
authors.forename: Seiji
authors.initials: S
authors.lastname: Ueda
authors.forename: Seiya
authors.initials: S
authors.lastname: Kato
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Imaizumi
mesh_terms: D000804:Angiotensin II / Q000037:antagonists & inhibitors* / Q000502:physiology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015843:Serpins / Q000378:metabolism*; D015398:Signal Transduction; D014471:Umbilical Veins; D015854:Up-Regulation; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D000804:Angiotensin II; D018932:Chemokine CCL2; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; D016328:NF-kappa B; D009414:Nerve Growth Factors; D010750:Phosphoproteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor; C056558:CYBB protein, human; C498910:NOX4 protein, human; C086986:CYBA protein, human