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Induction of BMP4 in Vascular Smooth Muscle Cells by Shear Stress
Author(s) -
Rouhanizadeh Mahsa,
Lin Tiantian C,
Miller Jordan D,
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.a1176-b
Subject(s) - vascular smooth muscle , shear stress , bone morphogenetic protein 2 , bone morphogenetic protein 4 , pulsatile flow , messenger rna , chemistry , cell , medicine , anatomy , bone morphogenetic protein , endocrinology , biology , smooth muscle , materials science , in vitro , biochemistry , composite material , gene
Bone morphogenic protein‐4 (BMP4) promotes inflammatory responses and vascular calcification. Smooth muscle cells proliferation and migration occur in the denuded arteries post angioplasty. We assessed whether pulsatile shear stress (PSS) vs. oscillatory shear stress (OSS) regulated BMP2 and BMP4 expression in bovine aortic endothelial cell (BAEC) and vascular smooth muscle cell (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. BMP‐mRNA was measured with real‐time RT‐PCR Results a) VSMC (Fig. 1): OSS significantly up‐regulated BMP4 by 2.2‐fold and PSS by 1.64‐fold ( P <0.05, n=3) in VSMC. OSS significantly down‐regulated BMP2 by 0.32‐fold ( P < 0.05), but PSS‐induced down‐regulation was statistically insignificant. Control samples were under static condition. 1Smooth Muscle cell BMP mRNA expression b) BAEC (Fig. 2): OSS up‐regulated BMP2 by 2‐fold, and BMP4 by 1.5‐fold in BAEC. Similarly, PSS induced BMP2 and BMP4 expression by 1.6‐ and 1.4‐fold, respectively. However, these differences were statistically insignificant.2Endothelial BMP mRNA expressionDiscussion OSS was a stronger inducer of BMP4 expression in VSMC than PSS. The findings suggest that shear stress mediated increases in BMP4 expression may contribute to inflammation in the denuded regions of stented arteries.