Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.14.3 (luciferase)
 38,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Th2 cytokines induce the release of vascular endothelial growth factor (VEGF) from cultured human airway smooth muscle cells. The objective of this study was to examine the mechanistic basis for IL-4- and IL-13-induced VEGF release and to determine whether genetic differences are responsible for donor-to-donor variability in VEGF release. We measured VEGF mRNA expression by real-time PCR, mRNA stability using actinomycin D, and promoter activity with a VEGF-promoter luciferase reporter construct. We measured IL-4- and IL-13-induced VEGF release in cells from 21 donors by ELISA, genotyped the cells for common single nucleotide polymorphisms in the IL-4R alpha (Ile50Val, Ser478Pro, and Gln551Arg) and VEGF (-460T/C, -160C/T, -152G/A, +405C/G and +936 C/T) genes, and stratified the data by IL-4R alpha and VEGF genotype. IL-4 and IL-13 increased VEGF release and VEGF mRNA expression. IL-4 also increased mRNA stability but did not affect VEGF promoter activity. There was marked donor-to-donor variability in VEGF release from smooth muscle cells. The presence of Val50, Pro478/Arg551, or the Val50/Pro478/Arg551 IL-4R alpha haplotype had little effect on VEGF release. VEGF genotype at +405 or +936 alone had no effect on VEGF release, whereas cells bearing at least one -460C/-152A/+405G VEGF allele had lower release of VEGF in response to IL-13 or IL-4 than cells with other genotypes. Our data suggest that IL-4 and IL-13 mediate their effects on VEGF expression post-transcriptionally and indicate that polymorphisms in the VEGF, but not the IL-4R alpha, gene affect VEGF release from smooth muscle cells.
 ...
PMID:Interleukin-13 and interleukin-4 induce vascular endothelial growth factor release from airway smooth muscle cells: role of vascular endothelial growth factor genotype. 1621 Jun 93

Repeats (27-nt) in intron 4 have been shown to play a cis-acting role in endothelial nitric oxide synthase (eNOS) promoter activity. We hypothesize that the 27-nt repeats could be the source of small nuclear RNA specifically regulating eNOS expression. In this study, we used synthesized 27-nt RNA duplex and found that the eNOS gene transcriptional efficiency was reduced 63% (0.047 +/- 0.009 vs. 0.126 +/- 0.015, P < 0.01) by nuclear run-on assay. In endothelial cells transfected with the 27-nt small RNA duplex, we found that the eNOS mRNA and protein levels were decreased by >64% (P < 0.01). Conversely, a randomly selected 27-nt from luciferase gene had no effect on the eNOS expression. Furthermore, this eNOS silencing effect appeared to be reversible under the stimulation of vascular endothelial growth factor (10 ng/ml), which is known to up-regulate eNOS expression. Using in situ hybridization and Northern blotting, we observed the presence of endogenous eNOS intron 4-derived 27-nt small RNA, which was confined to the nucleus. In summary, we demonstrated that intron-based microRNAs in eNOS can induce significant gene specific transcriptional suppression, which could be an effective negative feedback regulator for gene expression.
 ...
PMID:Regulation of endothelial nitric oxide synthase by small RNA. 1628 54

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.
 ...
PMID:All-trans retinoic acid inhibits vascular endothelial growth factor expression in a cell model of neutrophil activation. 1632 68

In its role as an endothelial cell proliferation and migration factor, vascular endothelial growth factor (VEGF) can affect peripheral circulation and therefore impact maximal oxygen consumption (Vo2 max). Because of the role of VEGF, and because variation in the VEGF gene has the ability to alter VEGF gene expression and VEGF protein level, we hypothesized that VEGF gene polymorphisms are related to VEGF gene expression in human myoblasts and Vo2 max before and after aerobic exercise training. We analyzed the effects of the VEGF -2578/-1154/-634 promoter region haplotype on VEGF gene expression by using a luciferase reporter assay in cultured human myoblasts and found that the AAG and CGC haplotypes resulted in significantly higher hypoxia-stimulated VEGF gene expression than the AGG and CGG haplotypes. Consistent with these results, we found that individuals with at least one copy of the AAG or CGC haplotype had higher Vo2 max before and after aerobic exercise training than did subjects with only the AGG and/or CGG haplotype. In conclusion, we found that VEGF -2578/-1154/-634 haplotype impacts VEGF gene expression in human myoblasts and is associated with Vo2 max. These results have potential implications for aerobic exercise training and may prove relevant in the study of pathological conditions that can be affected by angiogenesis, such as coronary artery disease and peripheral artery disease.
 ...
PMID:DNA sequence variation in the promoter region of the VEGF gene impacts VEGF gene expression and maximal oxygen consumption. 1633 27

Geldanamycin (GA), a benzoquinone ansamycin, is a naturally occurring inhibitor of heat shock protein (Hsp90), which regulates the transcription activity of hypoxia-inducible factor 1 (HIF-1alpha). Under hypoxia, HIF-1alpha is activated in tumor cells, and induces the transcription of vascular endothelial growth factor (VEGF), which is the prime regulator for angiogenesis. VEGF promotes the formation of new blood vessels by stimulating endothelial cell division and migration. This eventually forms a vascular network that allows for tumor growth and metastasis. In this study, we used GA to inhibit HIF-1alpha transcription function. Human prostate cancer DU-145 cells were incubated in a hypoxic chamber at 1% O(2) and 37 degrees C for different durations. Both mRNA and protein levels of HIF-1alpha and VEGF were upregulated under hypoxic conditions. We demonstrated that GA treatment of hypoxic DU-145 cells abolished the induction of HIF-1alpha protein in a time-dependent manner and decreased VEGF mRNA and its protein levels. The transient transfection of DU-145 cells with luciferase reporter gene construct (5HRE/hCMVmp-luc) showed that the transcriptional activity of HIF-1alpha was significantly induced in response to hypoxia, but inhibited by GA. In addition, using conditioned medium from GA-treated hypoxic cells led to a significant decrease in cell invasion in comparison with using conditioned medium from nontreated hypoxic cells. These data provide evidence for the important role of GA in inhibition of angiogenesis and also invasion mediated by HIF-1alpha in prostate cancer cells.
 ...
PMID:Effects of geldanamycin on HIF-1alpha mediated angiogenesis and invasion in prostate cancer cells. 1643 34

Hypoxia inducible factor (HIF), a master regulator of critical genes for cell survival under hypoxic conditions, is known to be related to tumorigenesis and progression of renal cell carcinoma. N-methylpyrrole (Py)-N-methylimidazole (Im) hairpin polyamides are synthetic organic compounds that recognize and bind to the minor grooves of specific DNA sequences. We synthesized three Py-Im hairpin polyamides targeting the flanking sequences of hypoxia responsive element (HRE; a binding site of HIF) in the promoter region of the vascular endothelial growth factor (VEGF) gene. The effects of the polyamides on HIF-induced transcription were evaluated by a luciferase assay using a reporter plasmid containing a VEGF promoter. Real time reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay were performed to examine the effects of the polyamides on the transcription and secretion of VEGF in A498 renal cell carcinoma cells, which have a frame-shift mutation in the von Hippel-Lindau gene. A combination of three Py-Im hairpin polyamides suppressed HIF-induced transcription in reporter assays using 293 cells and successfully suppressed transcription and translation of the VEGF gene in A498 cells. Inhibition of the HIF-HRE interaction was confirmed by an electrophoresis mobility shift assay. An approach using Py-Im hairpin polyamides may be a new strategy for the treatment of renal cell carcinoma.
 ...
PMID:Suppression of VEGF transcription in renal cell carcinoma cells by pyrrole-imidazole hairpin polyamides targeting the hypoxia responsive element. 1664 75

In oxygenated cells, hypoxia-inducible factor-1 (HIF-1) alpha subunits are rapidly degraded by a mechanism that involves ubiquitination by the von Hippel-Lindau tumor suppressor E3 ligase complex using 2-oxoglutarate as a substrate. We examined the effect of 2-oxoglutarate on the production of erythropoietin and vascular endothelial growth factor (VEGF). The expression of erythropoietin and VEGF protein were dose-dependently downregulated in Hep3B cells by the addition of 2-oxoglutarate. The promoter activity of VEGF-luciferase was dose-dependently downregulated by the addition of 2-oxoglutarate. Gel mobility shift assays revealed that the addition of 2-oxoglutarate dose-dependently inhibited HIF-1 binding activity, but did not affect GATA binding activity. Western blot analysis revealed that 2-oxoglutarate dose-dependently inhibited the HIF-1alpha protein level in Hep3B cells in hypoxic conditions. However, MG132 (the proteasome inhibitor) rescued the inhibition of HIF-1alpha protein expression by 2-oxoglutarate. Furthermore, under hypoxic conditions, 2-oxoglutarate dose-dependently inhibited tube formation in in vitro angiogenesis assays. These results indicate that 2-oxoglutarate treatment may be useful for the inhibition of angiogenesis.
 ...
PMID:2-Oxoglutarate downregulates expression of vascular endothelial growth factor and erythropoietin through decreasing hypoxia-inducible factor-1alpha and inhibits angiogenesis. 1688 94

Gene therapy with the vascular endothelial growth factor (VEGF) gene is a potential treatment for many disorders or injuries with ischemia. However, unregulated expression of VEGF may induce pathological angiogenesis, promoting tumor growth, diabetic proliferative retinopathy and rupture of atherosclerotic plaque. Therefore, the effective regulation of the gene expression is one of the requirements for the VEGF gene therapy. In this research, we evaluated the hypoxia-inducible gene expression system with the erythropoietin (Epo) enhancer and the Epo 3'-untranslated region (UTR). The luciferase plasmids were constructed with the Epo enhancer (pEpo-SV-Luc), the Epo 3'-UTR (pSV-Luc-EpoUTR) or both (pEpo-SV-Luc-EpoUTR). The polyethylenimine/plasmid complexes were transfected to 293 or A7R5 cells and the cells were incubated under normoxia or hypoxia. The results showed that the Epo enhancer or Epo 3'-UTR increased the target gene expression under hypoxia. pEpo-SV-Luc-EpoUTR showed the highest luciferase expression. The VEGF expression plasmid with the Epo enhancer and 3'-UTR was also constructed. The VEGF expression by pEpo-SV-VEGF-EpoUTR showed the highest specificity of the gene expression in the hypoxic cells. The results suggest that the VEGF plasmid with the Epo enhancer and the Epo 3'-UTR may be useful for gene therapy for ischemic diseases.
 ...
PMID:Hypoxia-inducible gene expression system using the erythropoietin enhancer and 3'-untranslated region for the VEGF gene therapy. 1696 97

Hypoxia-inducible factor-alpha (Hif-alpha) plays an important role in tumor growth by increasing resistance to apoptosis and the production of angiogenic factors, such as vascular endothelial growth factor (VEGF). Therefore, Hif-alpha is an attractive target for development of novel cancer therapeutics. We have generated Chinese hamster ovary cells, which stably express luciferase reporter construct under the control of a hypoxia response element to screen 15,000 compounds. We identified 40 compounds that inhibited hypoxic up-regulation of luciferase, and the top 30 compounds were further screened in a secondary assay using MDA-468 breast cancer cell line. Eight compounds were shown to inhibit VEGF expression in hypoxic cells at subtoxic concentrations. Three top putative Hif inhibitors, DJ12, DJ15, and DJ30, were chosen for further analysis. Transient transfection of cells with hypoxia-regulated luciferase reporter plasmids further validated that these compounds inhibit hypoxia up-regulated genes. All three compounds failed to inhibit Hif-1alpha protein levels but they did inhibit induction of downstream targets of Hif-alpha under hypoxia. Two of the three compounds were cell type specific, whereas compound DJ12 inhibited VEGF at subtoxic levels in breast cancer cell lines MDA-468 and ZR-75, melanoma cell line MDA-435, and pVHL mutant renal cancer cell lines RCC4 and 786-0. Compound DJ12 down-regulated mRNA of downstream targets of Hif-alpha, and significantly inhibited Hif-1alpha transactivation activity by blocking Hif-1alpha hypoxia response element-DNA binding. Our cell-based approach and deconvolution of the inhibitory effect of DJ12 has identified a novel compound that targets the hypoxia pathway by inhibiting Hif-alpha-inducible transcription.
 ...
PMID:Identification of novel small-molecule inhibitors of hypoxia-inducible factor-1 transactivation and DNA binding. 1698 52

Ginsenoside-Rg1, the most prevalent active constituent of ginseng, is a potent proangiogenic factor of vascular endothelial cells. This suggests that Rg1 may be a new modality for angiotherapy. Rg1 can activate the glucocorticoid receptor (GR). However, the regulatory steps downstream from GR that promote Rg1-induced angiogenesis have not been elucidated. Here we showed for the first time that Rg1 was a potent stimulator of vascular endothelial growth factor (VEGF) expression in human umbilical vein endothelial cells, and importantly this induction was mediated through a phosphatidylinositol 3-kinase (PI3K)/Akt and beta-catenin/T-cell factor-dependent pathway via the GR. Rg1 stimulation resulted in an increase in the level of beta-catenin, culminating its nuclear accumulation, and subsequent activation of VEGF expression. Transfection of a stable form of beta-catenin (S37A) or the use of a glycogen synthase kinase 3beta inhibitor to stabilize beta-catenin induced VEGF synthesis, whereas small interfering RNA-mediated down-regulation of beta-catenin did not, confirming that the effect was beta-catenin-specific. Using a luciferase reporter gene assay, we observed that Rg1 increased T-cell factor/lymphoid enhancer factor transcriptional activity. These events were mediated via a PI3K-dependent phosphorylation of the inhibitory Ser9 residue of glycogen synthase kinase 3beta. In addition, the GR antagonist RU486 was able to inhibit Rg1-induced PI3K/Akt and beta-catenin activation. These findings provide new insights into the mechanism responsible for Rg1 functions.
 ...
PMID:Ginsenoside-Rg1 induces vascular endothelial growth factor expression through the glucocorticoid receptor-related phosphatidylinositol 3-kinase/Akt and beta-catenin/T-cell factor-dependent pathway in human endothelial cells. 1700 23


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>