TY - JOUR
T1 - Characterization of thrombin receptor expression during vascular lesion formation
AU - Wilcox, Josiah N.
AU - Rodriguez, Jose
AU - Subramanian, Romesh
AU - Ollerenshaw, Jeremy
AU - Zhong, Chizheng
AU - Hayzer, David J.
AU - Horaist, Christopher
AU - Hanson, Stephen R.
AU - Lumsden, Alan
AU - Salam, Tarek A.
AU - Kelly, Andrew B.
AU - Harker, Laurence A.
AU - Runge, Marschall
PY - 1994/12
Y1 - 1994/12
N2 - Blood vessels respond to injury by initiating cell proliferation and migration that result in vascular lesion formation. To determine the roles of thrombin and the thrombin receptor in this process, we characterized thrombin receptor expression in normal and injured arteries, thrombin receptor- mediated smooth muscle cell mitogenesis, and the regulation of thrombin receptor mRNA expression in vitro. Thrombin receptor mRNA was not detected in normal rat or baboon arteries by in situ hybridization. Immunohistochemistry using an antithrombin receptor antibody (TR-R9), directed against the thrombin cleavage site of the rat aortic smooth muscle cell thrombin receptor, revealed low-level staining for thrombin receptor protein in endothelial cells and smooth muscle cells of normal arteries. In contrast, balloon catheter injury increased thrombin mRNA expression in medial smooth muscle cells within 6 hours. This increased thrombin receptor expression continued within the media and in neointimal cells throughout vascular lesion formation, predominantly in areas of active cell proliferation. In vitro, α- thrombin stimulates rat aortic smooth muscle cell proliferation in a concentration-dependent manner. That thrombin receptor activation is required for the mitogenic response was confirmed by demonstrating that the polyclonal antibody TR-R9 inhibits thrombin-induced cell proliferation. Thrombin receptor mRNA synthesis was induced by both basic fibroblast growth factor (maximal stimulation of 1.8-fold at 1 hour) and platelet-derived growth factor (maximal stimulation of 2.4-fold at 8 and 24 hours) in quiesced cultured rat aortic smooth muscle cells. In summary, upregulation of smooth muscle cell thrombin receptor expression occurs very early after vascular injury and continues throughout neointimal development. In vitro, the mitogenic effects of thrombin are receptor-mediated, and thrombin receptor expression is regulated by growth factors with established roles in vascular lesion formation. These data are consistent with the hypothesis that thrombin, in concert with basic fibroblast growth factor and platelet- derived growth factor, is a mitogen for the initiation and maintenance of cell proliferation after vascular injury.
AB - Blood vessels respond to injury by initiating cell proliferation and migration that result in vascular lesion formation. To determine the roles of thrombin and the thrombin receptor in this process, we characterized thrombin receptor expression in normal and injured arteries, thrombin receptor- mediated smooth muscle cell mitogenesis, and the regulation of thrombin receptor mRNA expression in vitro. Thrombin receptor mRNA was not detected in normal rat or baboon arteries by in situ hybridization. Immunohistochemistry using an antithrombin receptor antibody (TR-R9), directed against the thrombin cleavage site of the rat aortic smooth muscle cell thrombin receptor, revealed low-level staining for thrombin receptor protein in endothelial cells and smooth muscle cells of normal arteries. In contrast, balloon catheter injury increased thrombin mRNA expression in medial smooth muscle cells within 6 hours. This increased thrombin receptor expression continued within the media and in neointimal cells throughout vascular lesion formation, predominantly in areas of active cell proliferation. In vitro, α- thrombin stimulates rat aortic smooth muscle cell proliferation in a concentration-dependent manner. That thrombin receptor activation is required for the mitogenic response was confirmed by demonstrating that the polyclonal antibody TR-R9 inhibits thrombin-induced cell proliferation. Thrombin receptor mRNA synthesis was induced by both basic fibroblast growth factor (maximal stimulation of 1.8-fold at 1 hour) and platelet-derived growth factor (maximal stimulation of 2.4-fold at 8 and 24 hours) in quiesced cultured rat aortic smooth muscle cells. In summary, upregulation of smooth muscle cell thrombin receptor expression occurs very early after vascular injury and continues throughout neointimal development. In vitro, the mitogenic effects of thrombin are receptor-mediated, and thrombin receptor expression is regulated by growth factors with established roles in vascular lesion formation. These data are consistent with the hypothesis that thrombin, in concert with basic fibroblast growth factor and platelet- derived growth factor, is a mitogen for the initiation and maintenance of cell proliferation after vascular injury.
KW - angioplasty
KW - atherosclerosis
KW - basic fibroblast growth factor
KW - platelet-derived growth factor
KW - restenosis
KW - thrombin
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U2 - 10.1161/01.RES.75.6.1029
DO - 10.1161/01.RES.75.6.1029
M3 - Article
C2 - 7955141
AN - SCOPUS:0027967395
VL - 75
SP - 1029
EP - 1038
JO - Circulation Research
JF - Circulation Research
SN - 0009-7330
IS - 6
ER -