c-Src induces phosphorylation and translocation of p47phox: role in superoxide generation by angiotensin II in human vascular smooth muscle cells

Touyz, R.M. , Yao, G. and Schriffin, E.L. (2003) c-Src induces phosphorylation and translocation of p47phox: role in superoxide generation by angiotensin II in human vascular smooth muscle cells. Arteriosclerosis, Thrombosis, and Vascular Biology, 23(6), pp. 981-987. (doi: 10.1161/01.ATV.0000069236.27911.68)

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Abstract

<b>Objectives—</b> The aim of this study was to determine molecular mechanisms whereby c-Src regulates angiotensin II (Ang II)-mediated NAD(P)H oxidase-derived ·O2− in human vascular smooth muscle cells (VSMCs).<p></p> <b>Methods and Results—</b> VSMCs from human small arteries were studied. Ang II increased NAD(P)H oxidase-mediated generation of ·O2− and H2O2 (P<0.01). PP2, c-Src inhibitor, attenuated these effects by 70% to 80%. Immunoprecipitation of p47phox, followed by immunoblotting with antiphosphoserine antibody, demonstrated a rapid increase (1.5- to 2-fold) in p47phox phosphorylation in Ang II-stimulated cells. This was associated with p47phox translocation from cytosol to membrane, as assessed by immunoblotting and immunofluorescence. PP2 abrogated these effects. Long-term Ang II stimulation (6 to 24 hours) increased NAD(P)H oxidase subunit expression. c-Src inhibition decreased abundance of gp91phox, p22phox, and p47phox. Confirmation of c-Src-dependent regulation of NAD(P)H oxidase was tested in VSMCs from c-Src−/− mice. Ang II-induced ·O2− generation was lower in c-Src−/− than c-Src+/+ counterparts. This was associated with decreased p47phox phosphorylation, blunted Ang II-stimulated NAD(P)H oxidase activation, and failure of Ang II to increase subunit expression.<p></p> <b>Conclusions—</b> c-Src regulates NAD(P)H oxidase-derived ·O2− generation acutely by stimulating p47phox phosphorylation and translocation and chronically by increasing protein content of gp91phox, p22phox, and p47phox in Ang II-stimulated cells. These novel findings identify NAD(P)H oxidase subunits, particularly p47phox, as downstream targets of c-Src.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Touyz, Professor Rhian
Authors: Touyz, R.M., Yao, G., and Schriffin, E.L.
College/School:College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Arteriosclerosis, Thrombosis, and Vascular Biology
Publisher:American Heart Association
ISSN:1079-5642
ISSN (Online):1524-4636
Published Online:27 March 2003

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