ABSTRACT
Nitric oxide (NO) seems to play a pivotal role in the vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation. This study was designed to investigate the role and intracellular signal pathway of endothelial nitric oxide synthase (eNOS) activation induced by VEGF. ECV 304 cells were treated with betaVEGF(165) and then cell proliferation, eNOS protein and mRNA expression levels were analyzed to elucidate the functional role of eNOS in cell proliferation induced by VEGF. After exposure of cells to betaVEGF(165) , eNOS activity and cell growth were increased by approximately two-fold in the betaVEGF(165) -treated cells compared to the untreated cells. In addition, VEGF stimulated eNOS expression at both the mRNA and protein levels in a dose-dependent manner. Phosphatidylinositol-3 kinase (PI-3K) inhibitors were used to assess PI-3K involvement in eNOS regulation. LY294002 was found to attenuate VEGF-stimulated eNOS expression. Wortmannin was not as effective as LY294002, but the reduction effect was detectable. Cells activated by VEGF showed increased ERK1/2 levels. Moreover, the VEGF-induced eNOS expression was reduced by the PD98059, MAPK pathway inhibitor. This suggests that eNOS expression might be regulated by PI-3K and the ERK1/2 signaling pathway. In conclusion, betaVEGF(165) induces ECV 304 cell proliferation via the NO produced by eNOS. In addition, eNOS may be regulated by the PI-3K or mitogen-activated protein kinase pathway.
Subject(s)
Phosphatidylinositol 3-Kinase/antagonists & inhibitors , Cell Division/drug effects , Cell Line , Endothelial Growth Factors/metabolism , Endothelium, Vascular/cytology , Gene Expression Regulation, Enzymologic , Lymphokines/metabolism , MAP Kinase Signaling System , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type III , Signal Transduction , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth FactorsABSTRACT
OBJECTIVE: To determine of the regulation of cyclooxygenase-2 (COX-2) expression by Interleukin-1beta in WISH cells. METHODS: Amnion WISH cells were incubated in media containing increasing concentrations of IL-1beta or with various inhibitors. Increased COX-2 expression was determined by Western blot analysis with anti-COX-2 antibody. Concomitant measurements of culture media PGE2 were made by an enzyme immunoassay. RESULTS: The COX-2 and prostaglandin E2 production induced by IL-1beta increased in a dose- and time-dependent manner. One of the regulating factors that induced COX-2 by IL-1beta was protein kinase C (PKC). PKC inhibitor, Ro 31-8220 was pretreated and continued treating by IL-1beta. Then, PKC inhibitor completely blocked COX-2 protein induction by IL-1beta. In contrast, COX-2 induction by IL-1beta after pretreating PKC stimulator, phobol 12-myristate 13-acetate was potentiated with synergism. Another factor in controlling COX-2 protein induction was identified as phosphatidylinositol 3-kinase (PI 3K). COX-2 protein induction by IL-1beta after pretreating PI 3K inhibitors, wortmannin and LY294002 strongly increased. This kind of result reflected that PI 3K act as negative regulator. COX-2 induction by IL-1beta was known to be regulated in not only transcription step, but also translation step after performing experiment of actinomycin and cycloheximide treatment. CONCLUSION: COX-2 protein and prostaglandin E2 production induced by IL-1beta were controlled by many factors in amnion cell. Among those factors, PKC and PI 3K have an important role, but their control mechanism act as positive and negative, respectively.