Cyclophilin A Is Required for Angiotensin II–Induced p47phox Translocation to Caveolae in Vascular Smooth Muscle Cells

• DOI: 10.1161/atvbaha.113.301894
• Publication Date: 2013-07-12T05:39:07Z
• Authors: Nwe Nwe Soe; Mark Sowden; Padmamalini Baskaran; Elaine M. Smolock; Yeonghwan Kim; Patrizia Nigro; Bradford C. Berk
• Keywords: Cypa

Angiotensin II (AngII) signal transduction in vascular smooth muscle cells (VSMC) is mediated by reactive oxygen species (ROS). Cyclophilin A (CyPA) a ubiquitously expressed cytosolic protein that possesses peptidyl-prolyl cis-trans isomerase activity, scaffold function, and significantly enhances AngII-induced ROS production VSMC. We hypothesized CyPA regulates generation promoting translocation of NADPH oxidase subunit p47phox to caveolae the plasma membrane.Overexpression CyPA-deficient VSMC (CyPA(-/-)VSMC) increased AngII-stimulated production. Nicotinamide adenine dinucleotide phosphate (NADPH) inhibitors (VAS2870 or diphenylene iodonium) attenuated p47phox-overexpressing CyPA(-/-)VSMC. Cell fractionation sucrose gradient analyses showed membrane translocation, specifically caveolae, was reduced CyPA(-/-)VSMC compared with wild-type-VSMC. Immunofluorescence studies demonstrated AngII colocalization membrane. In addition, immunoprecipitation followed immunoblotting actin interaction. cell cytoskeleton association Mechanistically, inhibition phosphorylation phox homology domain deletion Finally, cyclosporine CyPA-peptidyl-prolyl mutant, R55A, inhibited VSMC, suggesting activity required for their interaction.These findings provide mechanism which an important regulator through interaction cytoskeleton, caveolae.