title: The effect of shear stress on human endothelial cells seeded on cylindrical viscoelastic conduits: an investigation of gene expression.
abstract: The present study assesses the effect of physiological shear stress on gene expression from human ECs (endothelial cells) seeded on a small-diameter cylindrical bypass graft constructed from nanocomposite based on poly(carbonate-silsesquioxane-bridge-urea)urethane. ECs were seeded on to 5-mm-diameter conduits, placed in a physiological flow circuit and exposed to 1 or 4 h of shear stress at 1.4+/-0.3 Pa. Subsets of conduits were incubated at 37 degrees C and 5% CO2/95% O2 for a further 4 h to determine if gene expression returned to basal levels. PCR was conducted for glyceraldehyde-3-phosphate dehydrogenase, TGFbeta-1 (transforming growth factor beta-1), COL-1 (collagen-1) and PECAM-1 (platelet/EC adhesion molecule-1). Increases in gene expression were seen following flow in nanocomposite conduits. These were significant at 4 h for TGFbeta-1, COL-1 and PECAM-1. After a 4 h recovery period, there were no significant differences in gene intensity, suggesting that this change is transient. These data prove that mRNA can be obtained from ECs seeded on tubular conduits and exposed to shear stress and that gene-expression studies can be successfully carried out. We believe this is a substantial improvement on studies based on flat sheets.
authors.affiliation: BTEC (Biomaterials and Tissue Engineering Centre), Academic Division of Surgical and Interventional Sciences, University College London, Rowland Hill, and Vascular Unit, Royal Free Hampstead NHS Trust Hospital, London NW3 2PF, UK.
authors.forename: Dina S
authors.initials: DS
authors.lastname: Vara
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Punshon
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Sales
authors.forename: George
authors.initials: G
authors.lastname: Hamilton
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Seifalian
mesh_terms: D040761:Biomimetic Materials / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis / Q000235:genetics; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis / Q000235:genetics; D011673:Pulsatile Flow; D012333:RNA, Messenger / Q000096:biosynthesis*; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis / Q000235:genetics; D014471:Umbilical Veins / Q000166:cytology* / Q000502:physiology
chemical_list: D024042:Collagen Type I; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases