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Spatial variations regulation of expression of CuZn‐SOD and Mn‐SOD by shear stress in vascular tissue
Author(s) -
Rouhanizadeh Mahsa,
Lin Tiantian C,
Chu Yi,
Heistad Donald,
Hsiai Tzung K
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1452-c
Subject(s) - sod2 , shear stress , vascular smooth muscle , extracellular , chemistry , pulsatile flow , superoxide dismutase , medicine , andrology , endocrinology , biology , anatomy , oxidative stress , materials science , microbiology and biotechnology , smooth muscle , composite material
There are important spatial variations between shear stress and focal and eccentric atherosclerotic lesions. We tested whether pulsatile shear stress (PSS) vs. oscillatory shear stress (OSS) regulates SOD isoforms; namely, SOD1 (CuZn‐SOD), SOD2 (Mn‐SOD), and SOD3 (extracellular SOD), in bovine aortic endothelial cells (BAEC) and vascular smooth muscle cells (VSMC). Methods Confluent BAEC and VSMC monolayers were exposed to PSS at a mean shear stress (τ ave ) of 23 dyn.cm −2 and a temporal gradient (∂τ/∂ t) at 71 dyn.cm . −2. sec −2 ; and OSS at τ ave = 0.02 ± 3 dyn.cm −2 in a dynamic parallel plate flow system for 4 hours. SOD‐mRNA isoforms were measured with real‐time RT‐PCR. Results a)BAEC (Fig. 1 ): SOD2 was significantly up‐regulated in BAEC in response to shear stress ( P <0.05, n=3). PSS increased SOD2 expression by 10‐fold and OSS by 5‐fold. SOD1 was increased by 2‐fold in response to PSS, but remained unchanged in response to OSS. SOD3 did not respond to shear stress. 1Endothelial SOD mRNA expressionb)VSMC (Fig. 2 ): SOD2 was up‐regulated in SMC in response to PSS by 2‐fold, but was down‐regulated in response to OSS (P < 0.05, n=3). SOD1 expressed the similar trend, but was statistically insignificant. SOD3 expression was statistically insignificant. 2Smooth muscle SOD mRNA expressionConclusion Shear stress increased expression of SOD1 and ‐2 suggesting that spatial variations in shear stress may contribute to spatial differences in vascular oxidative stress.