scholarly journals All-Trans Retinoic Acid Inhibits Vascular Endothelial Growth Factor Expression in a Cell Model of Neutrophil Activation

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1264-1270 ◽  
Author(s):  
Meng Kian Tee ◽  
Jean-Louis Vigne ◽  
Robert N. Taylor

Infiltrating neutrophil granulocytes are a particularly rich source of vascular endothelial growth factor (VEGF) in the endometrium and may contribute to the angiogenesis of endometriosis lesions. The objective of this study is to evaluate the expression and regulation of VEGF in endometrial neutrophils and in a model of neutrophil differentiation relevant to endometriosis. Immunohistochemistry was performed on endometriosis patient biopsies and cultured neutrophil-like HL-60 cells were assessed. The study was set in a reproductive biology division within an academic medical center. Endometrial biopsies were performed on women with endometriosis and HL-60 cells were treated with all-trans retinoic acid (atRA) and dimethyl sulfoxide in vitro. Immunofluorescence histochemistry, VEGF mRNA and protein quantification, and transfection studies of VEGF gene promoter-luciferase constructs were all main outcome measures. Immunofluorescence studies verified the presence of neutrophils in eutopic endometrium from women with endometriosis. Examination of the regulation of VEGF using differentiated HL-60 cells as a model, revealed that atRA induced a dose- and time-dependent suppression of VEGF mRNA and protein. Transient transfection, truncation, EMSA, and site-directed mutagenesis of human VEGF promoter-luciferase constructs in HL-60 cells indicated that atRA repressed VEGF gene transcription via a direct repeat 1 element located between −443 and −431 bp relative to the transcription initiation site. Because retinoic acid is synthesized de novo in endometrial cells under the influence of progesterone, our findings suggest that the up-regulated VEGF and angiogenesis in tissue from women with endometriosis may reflect failure of neutrophil differentiation in these cases, and provide a rationale for retinoid therapy in this condition.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4632-4632
Author(s):  
Li Li ◽  
Ri Zhang ◽  
Jiannong Cen ◽  
Ziling Zhu

Abstract Background: Vascular endothelial growth factor (VEGF), one of the most potent mediators of angiogenesis, plays an important role in tumor cell proliferation and migration. Elevated VEGF levels are found in both the plasma and the bone marrow of patients with chronic myelogeneous leukemia(CML). Moreover, the CML-associated oncogene Bcr-Abl induces endogenous secretion of VEGF. The aim of this study was to construct a lentiviral vector-mediated RNA interference (RNAi) of vascular endothelial growth factor (VEGF) gene and to investigate the effects of RNAi inhibiting VEGF gene alone or in combination with imatinib on the proliferation and apoptosis of K562 leukemic cell line. Methods: A lentiviral expression vector containing short hairpin RNA (shRNA ) targeting VEGF was constructed and cotransfected with the pPACKH1 packaging plasmids mixture into 293T cells by Lipofectamine 2000. K562 cells were infected with the packaged lentivirus. The levels of VEGF mRNA and protein were detected by real-time quantitative RT- PCR, Western blot and ELISA. Cellular proliferation was determined by trypan blue exclusion and MTT assay. imatinib -induced apoptosis was analyzed by flow cytometry. Results: The lentiviral shRNA vector targeting VEGF has been constructed and transfected into K562 cells successfully. The expression of VEGF mRNA and protein in K562-shVEGF cells transfected with pRNAT-shRNA were significantly inhibited when compared with those of K562 and K562–con cells (mock transfection). The proliferation rate of K562-shVEGF cells slowed down. After imatinib treatment, the percentages of apoptotic cells in K562-shVEGF cells increased more significantly than those of K562 and K562–con cells. Conclusion: Suppression of VEGF by lentivirus-mediated RNAi could effectively inhibit proliferation and increase the sensitivity of K562 cells to imatinib. These results indicate that Bcr/Abl-targeting compound in combination with anti-angiogenic therapies may provide a potent therapeutic strategy to CML.


1999 ◽  
Vol 10 (4) ◽  
pp. 907-919 ◽  
Author(s):  
J. A. Dibbens ◽  
D. L. Miller ◽  
A. Damert ◽  
W. Risau ◽  
M. A. Vadas ◽  
...  

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.


Blood ◽  
2002 ◽  
Vol 100 (10) ◽  
pp. 3767-3775 ◽  
Author(s):  
Matthias Mayerhofer ◽  
Peter Valent ◽  
Wolfgang R. Sperr ◽  
James D. Griffin ◽  
Christian Sillaber

Recent data suggest that vascular endothelial growth factor (VEGF), a cytokine involved in autocrine growth of tumor cells and tumor angiogenesis, is up-regulated and plays a potential role in myelogenous leukemias. In chronic myelogenous leukemia (CML), VEGF is expressed at high levels in the bone marrow and peripheral blood. We show here that the CML-associated oncogene BCR/ABL induces VEGF gene expression in growth factor–dependent Ba/F3 cells. Whereas starved cells were found to contain only baseline levels of VEGF mRNA, Ba/F3 cells induced to express BCR/ABL exhibited substantial amounts of VEGF mRNA. BCR/ABL also induced VEGF promoter activity and increased VEGF protein levels in Ba/F3 cells. Moreover, BCR/ABL was found to promote the expression of functionally active hypoxia-inducible factor-1 (HIF-1), a major transcriptional regulator of VEGF gene expression. BCR/ABL-induced VEGF gene expression was counteracted by the phosphoinositide 3-kinase (PI3-kinase) inhibitor LY294002 and rapamycin, an antagonist of mammalian target of rapamycin (mTOR), but not by inhibition of the mitogen-activated protein kinase pathway. Similarly, BCR/ABL-dependent HIF-1α expression was inhibited by the addition of LY294002 and rapamycin. Together, our data show that BCR/ABL induces VEGF- and HIF-1α gene expression through a pathway involving PI3-kinase and mTOR. BCR/ABL-induced VEGF expression may contribute to the pathogenesis and increased angiogenesis in CML.


2018 ◽  
Vol 26 (10) ◽  
pp. 1351-1359 ◽  
Author(s):  
Cecilia Y. Cheung ◽  
Debra F. Anderson ◽  
Marion Rouzaire ◽  
Loïc Blanchon ◽  
Vincent Sapin ◽  
...  

Vascular endothelial growth factor (VEGF) has been proposed as an important regulator of amniotic fluid absorption across the amnion into the fetal vasculature on the surface of the placenta. However, the activators of VEGF expression and action in the amnion have not been identified. Using the pregnant sheep model, we aimed to investigate the presence of the retinoic acid (RA) pathway in ovine amnion and to determine its effect on VEGF expression. Further, we explored relationships between RA receptors and VEGF and tested the hypothesis that RA modulates intramembranous absorption (IMA) through induction of amnion VEGF in sheep fetuses subjected to altered IMA rates. Our study showed that RA receptor isoforms were expressed in sheep amnion, and RA response elements (RAREs) were identified in ovine RARβ and VEGF gene promoters. In ovine amnion cells, RA treatment upregulated RARβ messenger RNA (mRNA) and increased VEGF transcript levels. In sheep fetuses, increases in IMA rate was associated with elevated VEGF mRNA levels in the amnion but not in the chorion. Further, RARβ mRNA was positively correlated with VEGF mRNA levels in the amnion and not chorion. We conclude that an RA pathway is present in ovine fetal membranes and that RA is capable of inducing VEGF. The finding of a positive relationship between amnion VEGF and RARβ during altered IMA rate suggests that the retinoid pathway may play a role through VEGF in regulating intramembranous transport across the amnion.


2008 ◽  
Vol 197 (2) ◽  
pp. 309-314 ◽  
Author(s):  
Angélica Morales ◽  
Sumiko Morimoto ◽  
Lorenza Díaz ◽  
Guillermo Robles ◽  
Vicente Díaz-Sánchez

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an endothelial cell mitogen, expressed essentially in steroidogenic cells. Recently, the expression of EG-VEGF in normal human pancreas and pancreatic adenocarcinoma has been demonstrated. Epidemiologically, pancreatic carcinogenesis is more frequent in males than females, and given that androgen receptors and testosterone biotransformation have been described in pancreas, we hypothesized that testosterone could participate in the regulation of EG-VEGF expression. In this study, we investigated the regulation of EG-VEGF gene expression by testosterone in normal rat pancreatic tissue and rat insulinoma cells (RINm5F). Total RNA was extracted from rat pancreas and cultured cells. Gene expression was studied by real-time PCR and protein detection by immunohistochemistry. Serum testosterone was quantified by RIA. Results showed that EG-VEGF is expressed predominantly in pancreatic islets and vascular endothelium, as well as in RINm5F cells. EG-VEGF gene expression was lower in the pancreas of rats with higher testosterone serum levels. A similar effect that was reverted by flutamide was observed in testosterone-treated RINm5F cells. In summary, testosterone down-regulated EG-VEGF gene expression in rat pancreatic tissue and RINm5F cells. This effect could be mediated by the androgen receptor. To our knowledge, this is the first time that a direct effect of testosterone on EG-VEGF gene expression in rat pancreas and RINm5F cells is demonstrated.


2017 ◽  
Vol 89 (5) ◽  
pp. 60-64 ◽  
Author(s):  
A V Shevchenko ◽  
V F Prokofyev ◽  
M A Korolev ◽  
N E Banshchikova ◽  
V I Konenkov

Aim. To analyze polymorphism in the regulatory regions of the vascular endothelial growth factor (VEGF) gene in female patients with rheumatoid arthritis (RA). Subjects and methods. The investigation enrolled 257 female patients with RA. A control group consisted of 297 women without chronic diseases. The investigators examined the single-nucleotide polymorphism of VEGF-А2578С in the promoter region (rs699947) and that of VEGF+С936Т 3 in the retranslated region (rs3025039) of the gene. Genotyping was performed by restriction fragment length polymorphism analysis. Results. There was an increase in the frequency of VEGF+936 CT and a reduction in that of the VEGF+936СС genotypes in the seronegative patients as compared to the healthy women. The VEGF+936СС genotype frequency was higher in the patients with seropositive RA than in the subgroup of seronegative patients. The frequency of the VEGF-2578СС genotype was increased in the patients with RA and rheumatoid nodules, as compared to the healthy women. Conclusion. The data presented suggest that the presence of certain VEGF gene variants located in the regulatory regions may reflect the nature of immunopathological mechanisms in RA.


1993 ◽  
Vol 4 (12) ◽  
pp. 1317-1326 ◽  
Author(s):  
J E Park ◽  
G A Keller ◽  
N Ferrara

Vascular endothelial growth factor (VEGF)mRNA undergoes alternative splicing events that generate four different homodimeric isoforms, VEGF121, VEGF165, VEGF189, or VEGF206. VEGF121 is a nonheparin-binding acidic protein, which is freely diffusible. The longer forms, VEGF189 or VEGF206, are highly basic proteins tightly bound to extracellular heparin-containing proteoglycans. VEGF165 has intermediate properties. To determine the localization of VEGF isoforms, transfected human embryonic kidney CEN4 cells expressing VEGF165, VEGF189, or VEGF206 were stained by immunofluorescence with a specific monoclonal antibody. The staining was found in patches and streaks suggestive of extracellular matrix (ECM). VEGF165 was observed largely in Golgi apparatus-like structures. Immunogold labeling of cells expressing VEGF189 or VEGF206 revealed that the staining was localized to the subepithelial ECM. VEGF associated with the ECM was bioactive, because endothelial cells cultured on ECM derived from cells expressing VEGF189 or VEGF206 were markedly stimulated to proliferate. In addition, ECM-bound VEGF can be released into a soluble and bioactive form by heparin or plasmin. ECM-bound VEGF189 and VEGF206 have molecular masses consistent with the intact polypeptides. The ECM may represent an important source of VEGF and angiogenic potential.


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