title: Laminar shear stress up-regulates peroxiredoxins (PRX) in endothelial cells: PRX 1 as a mechanosensitive antioxidant.
abstract: Shear stress plays a significant role in endothelial cell biology and atherosclerosis development. Previous work by our group has shown that fluid flow stimulates important functional changes in cells through protein expression regulation. Peroxiredoxins (PRX) are a family of antioxidant enzymes but have yet to be investigated in response to shear stress. Studies have shown that oscillatory shear stress (OS) increases reactive oxygen species (ROS) levels in endothelial cells, whereas laminar shear stress (LS) blocks this response. We hypothesized that PRX are responsible for the anti-oxidative effect of LS. To test this hypothesis, bovine aortic endothelial cells (BAEC) were subjected to LS (15 dyn/cm(2)), OS (+/-5 dyn/cm(2), 1 Hz), or static conditions for 24 h. Using Western blot and immunofluorescence staining, all six isoforms of PRX were identified in BAEC. When compared with OS and static, exposure to chronic LS up-regulated PRX 1 levels intracellularly. LS also increased expression of PRX 5 relative to static controls, but not OS. PRX exhibited broad subcellular localization, with distribution in the cytoplasm, Golgi, mitochondria, and intermediate filaments. In addition, PRX 1 knock down, using specific small interference RNA, attenuated LS-dependent reactive oxygen species reduction in BAEC. However, PRX 5 depletion did not. Together, these results suggest that PRX 1 is a novel mechanosensitive antioxidant, playing an important role in shear-dependent regulation of endothelial biology and atherosclerosis.
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Mowbray
authors.affiliation: Division of Life and Pharmaceutical Sciences and the Center for Cell Signaling and Drug Discovery Research, Seoul 120-750, Korea.
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Kang
authors.affiliation: Division of Life and Pharmaceutical Sciences and the Center for Cell Signaling and Drug Discovery Research, Seoul 120-750, Korea.
authors.forename: Sue Goo
authors.initials: SG
authors.lastname: Rhee
authors.affiliation: Division of Life and Pharmaceutical Sciences and the Center for Cell Signaling and Drug Discovery Research, Seoul 120-750, Korea; Department of Life Sciences, Ewha Womans University, Seoul 120-750, Korea. Electronic address: kangsw@ewha.ac.kr.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322; Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia 30322. Electronic address: hanjoong.jo@bme.gatech.edu.
authors.forename: Hanjoong
authors.initials: H
authors.lastname: Jo
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002417:Cattle; D002457:Cell Extracts; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D040542:Mechanotransduction, Cellular; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D013314:Stress, Mechanical; D013347:Subcellular Fractions; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D002457:Cell Extracts; D034741:RNA, Small Interfering; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins