title: Connective tissue growth factor is released from platelets under high shear stress and is differentially expressed in endothelium along atherosclerotic plaques.
abstract: Connective tissue growth factor (CTGF) is overexpressed in atherosclerotic blood vessels. To further investigate the role of CTGF in atherosclerosis, we examined whether CTGF is released from platelets by high shear stress, and whether the expression of CTGF along the atherosclerotic lesions depends on local hemodynamic conditions. Human platelets were subjected to 10 dyn/cm2 or 120 dyn/cm2 and analysed by Western blotting. Furthermore, longitudinal sections of 25 carotid plaques were immunohistochemically analysed for the endothelial expression of CTGF. A very low CTGF amount was secreted from platelets at low shear stress (11.4 +/- 3.9% of total CTGF in platelets). On the contrary, high shear stress caused a markedly increased CTGF release from platelets (29 +/- 13.8%, p = 0.07 vs low shear stress, n = 4). Immunohistochemical analyses showed that the mean numbers of CTGF-positive endothelial cells were significantly higher up-stream as compared with down-stream regions of the luminal surface of atherosclerotic vessels (21.3 +/- 3.6 vs 13.9 +/- 2.8 down-stream, p < 0.001). Moreover, in plaques undergoing intimal neovascularization, newly formed vessels accumulated particularly in up-stream parts of the lesions. In conclusion, this study demonstrated that CTGF is released from platelets by high shear stress. Furthermore, disturbed flow along atherosclerotic vessels may induce endothelial CTGF expression and contribute to the progress of atherosclerotic lesions.
authors.affiliation: Medical Clinic II, University of Erlangen-Nuremberg, Germany. Iwona_Cicha@yahoo.com
authors.forename: Iwona
authors.initials: I
authors.lastname: Cicha
authors.forename: Atilla
authors.initials: A
authors.lastname: Yilmaz
authors.forename: Yoji
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Nobuji
authors.initials: N
authors.lastname: Maeda
authors.forename: Werner G
authors.initials: WG
authors.lastname: Daniel
authors.forename: Margarete
authors.initials: M
authors.lastname: Goppelt-Struebe
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Garlichs
mesh_terms: D050197:Atherosclerosis / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D002340:Carotid Artery Diseases / Q000378:metabolism; D016893:Carotid Stenosis / Q000378:metabolism; D055513:Connective Tissue Growth Factor; D018056:Hemorheology; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D013314:Stress, Mechanical
chemical_list: C526317:CCN2 protein, human; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D055513:Connective Tissue Growth Factor