Glomerular endothelial cells in culture express and secrete vascular endothelial growth factor

1994 ◽  
Vol 266 (1) ◽  
pp. F81-F88 ◽  
Author(s):  
K. Uchida ◽  
S. Uchida ◽  
K. Nitta ◽  
W. Yumura ◽  
F. Marumo ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Protein Kinase ◽  
Mrna Abundance ◽  
Vascular Endothelial ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Glomerular Endothelial Cells ◽  
Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) is a specific growth factor for endothelial cells, and its abundant expression has been reported in kidney glomeruli. In this study, we focused on glomerular endothelial cells (GEN) as a possible source of VEGF secretion and sought to uncover a potential autocrine role of VEGF for GEN. Ribonuclease protection assay demonstrated VEGF mRNA expression in cultured GEN, and 46-kDa VEGF protein was detected in the conditioned medium by immunoblot analysis using polyclonal antibody raised against the NH2-terminal portion of VEGF. Removal of fetal bovine serum (FBS) from the culture medium for 2 h decreased VEGF mRNA abundance, which was restored by the readdition of FBS (10%) within 2 h. The effect of FBS was completely abolished by protein kinase inhibitor H-7 (10 microM), suggesting that FBS-stimulated VEGF mRNA induction involves activation of protein kinases. The treatment of GEN with 10(-7) M 12-O-tetradecanoylphorbol-13-acetate (TPA) increased the VEGF mRNA abundance fivefold, supporting the idea that VEGF expression is regulated by protein kinase C. [3H]thymidine incorporation into GEN treated with TPA (10(-7) M) was inhibited by neutralizing antibody for VEGF. Thus VEGF was identified as an autocrine growth factor for GEN in vitro. Its physiological role might be the regulation of GEN proliferation, and the induction of VEGF expression by FBS and TPA suggests its involvement in the response of glomerular capillary endothelial cells to injury in certain pathophysiological states.

Expression of Vascular Endothelial Growth Factor in Human Monocyte/Macrophages Stimulated with Lipopolysaccharide

2001 ◽  
Vol 85 (01) ◽  
pp. 171-176 ◽  
Author(s):  
Hiroyuki Itaya ◽  
Hidemi Yoshida ◽  
Masayuki Koyama ◽  
Sohei Suzuki ◽  
Kei Satoh ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Map Kinase ◽  
Human Monocyte ◽  
P38 Map Kinase ◽  
Vascular Endothelial ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Endothelial Growth Factor

SummaryVascular endothelial growth factor (VEGF) is a mitogen for endothelial cells. We have studied the production of VEGF by human macrophages in response to lipopolysaccharide (LPS). Macrophages stimulated with LPS expressed VEGF mRNA and protein in concentration- and time-dependent manners. The LPS-induced expression of VEGF was inhibited by cycloheximide pretreatment, which suggested that synthesis of certain factor(s) is required for the LPS activity. The induction of VEGF was also suppressed by SB203580, an inhibitor of p38 mitogen-activated protein (MAP) kinase. These results suggest that the LPS-induced VEGF expression depends on the p38-mediated expression of c-Jun, which constitutes the AP-1 complex and binds to the AP-1 site in the VEGF promoter. Pretreatment of the cells with dexamethasone did not affect the LPS-induced upregulation of VEGF mRNA but strongly inhibited VEGF protein production, and the involvement of posttranscriptional regulation on VEGF expression by dexamethasone was suggested. The conditioned medium of LPS-stimulated macrophages enhanced the growth of cultured endothelial cells and it was inhibited by an antibody against VEGF. We conclude that macrophages produce VEGF in response to the stimulation with LPS, which may be partly mediated by the p38 MAP kinase pathway.

scholarly journals Hypoxic Regulation of Vascular Endothelial Growth Factor mRNA Stability Requires the Cooperation of Multiple RNA Elements

1999 ◽  
Vol 10 (4) ◽  
pp. 907-919 ◽  
Author(s):  
J. A. Dibbens ◽  
D. L. Miller ◽  
A. Damert ◽  
W. Risau ◽  
M. A. Vadas ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Vascular Endothelial ◽  
Coding Region ◽  
Vegf Gene ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Rapid Degradation ◽  
Multiple Regions ◽  
Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) is a key regulator of developmental, physiological, and tumor angiogenesis. Upregulation of VEGF expression by hypoxia appears to be a critical step in the neovascularization of solid cancers. The VEGF mRNA is intrinsically labile, but in response to hypoxia the mRNA is stabilized. We have systematically analyzed the regions in the VEGF mRNA that are responsible for its lability under normoxic conditions and for stabilization in response to hypoxia. We find that the VEGF mRNA not only contains destabilizing elements in its 3′ untranslated region (3′UTR), but also contains destabilizing elements in the 5′UTR and coding region. Each region can independently promote mRNA degradation, and together they act additively to effect rapid degradation under normoxic conditions. Stabilization of the mRNA in response to hypoxia is completely dependent on the cooperation of elements in each of the 5′UTR, coding region, and 3′UTR. Combinations of any of two of these three regions were completely ineffective in responding to hypoxia, whereas combining all three regions allowed recapitulation of the hypoxic stabilization seen with the endogenous VEGF mRNA. We conclude that multiple regions in the VEGF mRNA cooperate both to ensure the rapid degradation of the mRNA under normoxic conditions and to allow stabilization of the mRNA in response to hypoxia. Our findings highlight the complexity of VEGF gene expression and also reveal a mechanism of gene regulation that could become the target for strategies of therapeutic intervention.

scholarly journals Vascular endothelial growth factor gene and protein: strong expression in thyroiditis and thyroid carcinoma

1999 ◽  
Vol 161 (1) ◽  
pp. 41-49 ◽  
Author(s):  
M Klein ◽  
E Picard ◽  
JM Vignaud ◽  
B Marie ◽  
L Bresler ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Thyroid Carcinoma ◽  
Vascular Endothelial ◽  
Vegf Mrna ◽  
Normal Thyroid ◽  
Thyroid Carcinomas ◽  
Endothelial Growth Factor ◽  
Immunostaining Score

Angiogenesis is implicated in several pathological conditions, such as inflammation and tumor growth. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is a potent stimulator of endothelial cell proliferation in vitro and in vivo. The present work aimed to compare VEGF expression in human normal thyroid glands, thyroiditis tissue and thyroid carcinomas using immunohistochemistry and in situ hybridization (ISH). Both chronic lymphocytic thyroiditis and differentiated thyroid carcinomas were found to strongly express VEGF mRNA and encode larger amounts of VEGF than normal thyroid tissue as attested by a VEGF immunostaining score. In addition, tumor samples from patients with metastases showed a higher immunostaining score than their non-metastatic counterparts (P<0.05). Carcinomas with the greatest contents of VEGF mRNA and VEGF protein had the most intense mitogenic activity. Special focus on endothelial cells showed intense mitogenic activity in neoplastic tissues in contrast to the total quiescence of endothelial cells in non-tumoral tissues. An intense VEGF production by differentiated thyroid carcinoma, attested either by a higher immunostaining score or a strong VEGF mRNA expression using ISH, could be a promising marker of tumor aggressiveness and may also be useful as a predictor of metastatic potential.

Vascular Endothelial Growth Factor Enhances the Expression of Urokinase Receptor in Human Endothelial Cells via Protein Kinase C Activation

2001 ◽  
Vol 85 (02) ◽  
pp. 296-302 ◽  
Author(s):  
Marielle Kroon ◽  
Pieter Koolwijk ◽  
Mario Vermeer ◽  
Bea van der Vecht ◽  
Victor van Hinsbergh
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Receptor Expression ◽  
Vascular Endothelial ◽  
Human Endothelial Cells ◽  
Kinase C ◽  
Endothelial Growth Factor

SummaryAmong other proteolytic enzymes, the urokinase-type plasminogen activator (u-PA)/plasmin cascade contributes to cell migration and the formation of capillary-like structures in a fibrinous exudate. The u-PA receptor (u-PAR) focuses proteolytical activity on the cell surface of the endothelial cell and hereby accelerates the pericellular matrix degradation. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)-2 enhance u-PA receptor expression in human endothelial cells. In this paper we show that the protein kinase C (PKC) inhibitors Ro31-8220 and GF109203X inhibit VEGF165-induced u-PAR antigen expression in human endothelial cells, whereas PKC inhibition had no effect on FGF-2-induced u-PAR antigen enhancement. In addition, inhibition of PKC activity had no effect on VEGF165-or FGF-2-induced proliferation in human endothelial cells. We conclude that VEGF165 induces u-PAR via a PKC-dependent pathway, whereas proliferation is induced via a different pathway probably involving tyrosine phosphorylation of proteins downstream of the VEGF receptors.

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