TY - JOUR
T1 - Stimulation of a vascular smooth muscle cell NAD(P)H oxidase by thrombin
T2 - Evidence that p47(phox) may participate in forming this oxidase in vitro and in vivo
AU - Patterson, Cam
AU - Ruef, Johannes
AU - Madamanchi, Nageswara R.
AU - Barry-Lane, Patricia
AU - Hu, Zhaoyong
AU - Horaist, Chris
AU - Ballinger, Carol A.
AU - Brasier, Alan R.
AU - Bode, Christoph
AU - Runge, Marschall S.
PY - 1999/7/9
Y1 - 1999/7/9
N2 - Thrombin is a potent vascular smooth muscle cell (VSMC) mitogen. Because recent evidence implicates reactive oxygen intermediates (ROI) in VSMC proliferation in general and atherogenesis in particular, we investigated whether ROI generation is necessary for thrombin-induced mitogenesis. Treatment of human aortic smooth muscle cells with thrombin increased DNA synthesis, an effect that was antagonized by diphenyleneiodonium but not by other inhibitors of cellular oxidase systems. This effect of thrombin was accompanied by increased O2/·- and H2O2 generation and NADH/NADPH consumption. ROI generation in response to thrombin pretreatment could also be blocked by diphenyleneiodonium, suggesting that the NAD(P)H oxidase was necessary for ROI generation and thrombin-induced mitogenesis. Because of observed differences between the VSMC and neutrophil oxidase, we examined whether the cytosolic components of the phagocytic NAD(P)H oxidase were present in VSMC. p47(phox) and Rac2 were present in VSMC. Furthermore, thrombin increased expression of p47(phox) and Rac2 and stimulated their translocation to the cell membrane. We examined whether p47(phox) might be similarly regulated in vivo in a rat aorta balloon injury model and found that p47(phox) protein was increased after injury. Immunocytochemistry localized expression of p47(phox) to the neointima and media of injured arteries. Our data demonstrate that generation of O2/·- and H2O2 is required for thrombin-mediated mitogenesis in VSMC and that p47(phox) is regulated by thrombin in vitro and is associated with vascular lesion formation in vivo.
AB - Thrombin is a potent vascular smooth muscle cell (VSMC) mitogen. Because recent evidence implicates reactive oxygen intermediates (ROI) in VSMC proliferation in general and atherogenesis in particular, we investigated whether ROI generation is necessary for thrombin-induced mitogenesis. Treatment of human aortic smooth muscle cells with thrombin increased DNA synthesis, an effect that was antagonized by diphenyleneiodonium but not by other inhibitors of cellular oxidase systems. This effect of thrombin was accompanied by increased O2/·- and H2O2 generation and NADH/NADPH consumption. ROI generation in response to thrombin pretreatment could also be blocked by diphenyleneiodonium, suggesting that the NAD(P)H oxidase was necessary for ROI generation and thrombin-induced mitogenesis. Because of observed differences between the VSMC and neutrophil oxidase, we examined whether the cytosolic components of the phagocytic NAD(P)H oxidase were present in VSMC. p47(phox) and Rac2 were present in VSMC. Furthermore, thrombin increased expression of p47(phox) and Rac2 and stimulated their translocation to the cell membrane. We examined whether p47(phox) might be similarly regulated in vivo in a rat aorta balloon injury model and found that p47(phox) protein was increased after injury. Immunocytochemistry localized expression of p47(phox) to the neointima and media of injured arteries. Our data demonstrate that generation of O2/·- and H2O2 is required for thrombin-mediated mitogenesis in VSMC and that p47(phox) is regulated by thrombin in vitro and is associated with vascular lesion formation in vivo.
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U2 - 10.1074/jbc.274.28.19814
DO - 10.1074/jbc.274.28.19814
M3 - Article
C2 - 10391925
AN - SCOPUS:0033538516
SN - 0021-9258
VL - 274
SP - 19814
EP - 19822
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 28
ER -