1. Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells.
- Author
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Khoi PN, Park JS, Kim NH, and Jung YD
- Subjects
- Anthracenes pharmacology, Endothelial Cells metabolism, Flavonoids pharmacology, Humans, Imidazoles pharmacology, Mitogen-Activated Protein Kinases antagonists & inhibitors, NF-kappa B metabolism, Protein Kinase Inhibitors pharmacology, Pyridines pharmacology, RNA, Messenger chemistry, RNA, Messenger genetics, Receptors, Urokinase Plasminogen Activator genetics, Reverse Transcriptase Polymerase Chain Reaction, Transcription Factor AP-1 metabolism, Endothelial Cells drug effects, MAP Kinase Signaling System drug effects, Mitogen-Activated Protein Kinases metabolism, Nicotine pharmacology, Reactive Oxygen Species metabolism, Receptors, Urokinase Plasminogen Activator metabolism
- Abstract
Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H(2)O(2)) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H(2)O(2) increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2012
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