Oxidative stress and expression of p22phox are involved in the up-regulation of tissue factor in vascular smooth muscle cells in response to activated platelets.
Vascular injury after balloon angioplasty results in the rapid activation of platelets leading to the release of growth factors and vasoactive substances. In addition, up-regulation of tissue factor (TF) and an increased production of reactive oxygen species (ROS) have been detected at sites of vascular injury. We investigated whether platelet-derived products (PDP) released from activated human platelets increase ROS production, resulting in the induction of TF expression in vascular smooth muscle cells (SMC). PDP induced a time- and concentration-dependent increase in ROS generation in cultured SMC that was mediated mainly by PDGF-AB and TGF-beta1 and impaired by the flavin inhibitor diphenylene iodonium. Increased ROS formation was associated with enhanced mRNA levels of the small NAD(P)H oxidase subunit p22phox or its smooth muscle isoform. Transient transfection with a p22phox antisense vector decreased PDP-induced ROS generation. PDP up-regulated TF mRNA expression, which was redox sensitive and reduced by transfection of the p22phox antisense vector. In addition, PDP-stimulated reporter gene activity of two TF promoter constructs was decreased by coexpression of the p22phox antisense vector. These results indicate that activated platelets up-regulate TF expression and that this response involves ROS generation and a p22phox-containing NAD(P)H oxidase in SMC.
Institut für Kardiovaskuläre Physiologie, Klinikum der J. W. Goethe-Universität, 60590 Frankfurt/Main, Germany. A.Goerlach@em.uni-frankfurt.de
A
A
Görlach
R P
RP
Brandes
S
S
Bassus
N
N
Kronemann
C M
CM
Kirchmaier
R
R
Busse
V B
VB
Schini-Kerth
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D002478:Cells, Cultured; D003574:Cytochrome c Group / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D009252:NADPH Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D019255:NADPH Oxidases; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D015539:Platelet Activation / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects
D003574:Cytochrome c Group; D026901:Membrane Transport Proteins; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta; C095477:platelet-derived growth factor AB; D013925:Thromboplastin; D019255:NADPH Oxidases; C086986:CYBA protein, human; D009252:NADPH Dehydrogenase