title: Pharmacological inhibition of RhoA signaling prevents connective tissue growth factor induction in endothelial cells exposed to non-uniform shear stress.
abstract: Shear stress changes play an important role in atheroma formation. This study focussed on atherogenic protein expression under non-uniform shear stress and the pharmacological modulation of shear-related endothelial dysfunction. Bifurcating flow-through cell culture slides were used to expose HUVECs to steady laminar or non-uniform shear stress for 18 h at 10 dyn/cm(2). Protein expression was determined by immunofluorescence, and quantified using MetaVue software. Laminar shear stress resulted in cell alignment, reduced F-actin fibers, and significant induction of endothelial nitric oxide synthase expression. Under non-uniform shear stress at bifurcations, minor upregulation of adhesion molecules was observed. Connective tissue growth factor (CTGF) was significantly downregulated by laminar shear stress and induced in cells exposed to non-uniform shear stress. CTGF upregulation by non-uniform shear stress was RhoA-dependent, because it was almost completely inhibited in cells transfected with dominant negative RhoA-N19, and when cells were treated with 1 micromol/L simvastatin during flow. Pre-incubation of HUVECs with inhibitors of Rho-associated kinase before exposure to flow significantly suppressed the CTGF induction in regions of non-uniform shear stress. In conclusion, non-uniform shear stress-dependent CTGF expression requires active RhoA and can be prevented pharmacologically. Interference with shear stress-induced protein expression may inhibit endothelial dysfunction in atheroprone vessel regions.
authors: Medical Clinic 2, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address: Iwona_Cicha@yahoo.com.
authors: Iwona
authors: I
authors: Cicha
authors: Medical Clinic 4, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Margarete
authors: M
authors: Goppelt-Struebe
authors: Medical Clinic 4, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Susanne
authors: S
authors: Muehlich
authors: Medical Clinic 2, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Atilla
authors: A
authors: Yilmaz
authors: Medical Clinic 2, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Dorette
authors: D
authors: Raaz
authors: Medical Clinic 2, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Werner G
authors: WG
authors: Daniel
authors: Medical Clinic 2, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Christoph D
authors: CD
authors: Garlichs
mesh_terms: D050197:Atherosclerosis / Q000188:drug therapy / Q000503:physiopathology; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D017874:Immediate-Early Proteins / Q000187:drug effects / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D012212:Rheology; D015398:Signal Transduction / Q000187:drug effects; D019821:Simvastatin / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology; D054460:rho-Associated Kinases / Q000187:drug effects; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism
chemical_list: C526317:CCN2 protein, human; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D055513:Connective Tissue Growth Factor; D019821:Simvastatin; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein