Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiogenesis is important in the pathophysiology of endometriosis, a condition characterized by implantation of ectopic endometrium in the peritoneal cavity. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor involved in physiological and pathological angiogenesis, and elevated levels of VEGF are found in peritoneal fluid of patients with endometriosis. Our aim was to investigate the site of expression and regulation of VEGF in endometriosis. VEGF immunoreactivity was found in tissue macrophages present in ectopic endometrium and in activated peritoneal fluid macrophages. Macrophage activation was highest in women with endometriosis, and media conditioned by peritoneal fluid macrophages from these women caused a VEGF-dependent increase in endothelial cell proliferation above that seen from normal women. Peritoneal fluid macrophages secreted VEGF in response to ovarian steroids, and this secretion was enhanced after activation with lipopolysaccharide. Peritoneal fluid macrophages expressed receptors for steroid hormones. VEGF receptors flt and KDR (kinase domain receptor) were also detected, suggesting autocrine regulation. During the menstrual cycle, expression of flt was constant but that of KDR was increased in the luteal phase, at which time the cells migrated in response to VEGF. KDR expression and the migratory response were significantly higher in patients with endometriosis. This study demonstrates that activated macrophages are a major source of VEGF in endometriosis and that this expression is regulated directly by ovarian steroids.
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PMID:Vascular endothelial growth factor is produced by peritoneal fluid macrophages in endometriosis and is regulated by ovarian steroids. 875 60

Vascular endothelial growth factor (VEGF) is an angiogenic peptide with vascular permeability and relaxing properties. This study assessed whether peritoneal macrophages of cirrhotic patients can be up-regulated to produce VEGF under proper stimulatory conditions. Macrophages were isolated from ascites. VEGF protein secretion and mRNA expression were measured in basal conditions and after stimulation with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), and interleukin-1 (IL-1). These substances induced a time- and dose-dependent increase in both VEGF production and transcript expression. Assays with actinomycin D showed that VEGF mRNA induction is secondary to both higher VEGF gene transcription and mRNA stability. Ascites and plasma concentration of VEGF was also measured in cirrhotic patients with (n = 15) and without (n = 10) spontaneous bacterial peritonitis (SBP). Plasma values did not differ between both groups of patients. However, ascites VEGF levels were higher in SBP patients than in noninfected cirrhotic patients (710 +/- 183 vs. 94 +/- 15 pg/mL; P <.025). These results indicate that cytokines and LPS markedly increase VEGF protein secretion and mRNA expression in macrophages of cirrhotic patients, and suggest that this substance could be an important mediator of the pronounced arterial vasodilation frequently occurring in SBP patients.
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PMID:Vascular endothelial growth factor production in peritoneal macrophages of cirrhotic patients: regulation by cytokines and bacterial lipopolysaccharide. 1009 46

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis and is constitutively expressed in the synovium of rheumatoid arthritis (RA). Over-expression of VEGF may play an important role in pathogenic vascularization and synovial hyperplasia of RA. In the present study, we examined whether disease-modifying anti-rheumatic drugs (DMARDs), including bucillamine (BUC), gold sodium thiomalate (GST), methotrexate (MTX) and salazosulfapiridine (SASP), act by inhibiting the production of VEGF by cultured synovial cells of patients with RA. Treatment of cultured synoviocytes with lipopolysaccharide (LPS) significantly increased VEGF production by cultured synovial cells. BUC significantly inhibited LPS-induced VEGF production, while GST tended to inhibit the production of VEGF. The inhibitory effects on VEGF production were dose-dependent. In contrast, MTX and SASP did not affect VEGF production. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that BUC also inhibited LPS-induced VEGF mRNA expression in RA synovial cells. The present study provides the first evidence that BUC inhibits VEGF production and the expression of its mRNA in synovial cells of RA patients. Our results indicate that the anti-rheumatic effects of BUC are mediated by suppression of angiogenesis and synovial proliferation in the RA synovium through the inhibition of VEGF production by synovial cells.
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PMID:Inhibitory effects of anti-rheumatic drugs on vascular endothelial growth factor in cultured rheumatoid synovial cells. 1033 31

Endothelial cells in culture were exposed during four hours to the apoptosis inducing agents endotoxin (lipopolysaccharide, LPS) and Fas-ligand mimicking antibody in various concentrations. With addition of a deletion primer as internal standard a competitive RT-PCR was performed to measure semi-quantitatively the expression of mRNA of Vascular endothelial growth factor (VEGF). It appeared that endothelial cells survive increasing amounts of LPS and show a concentration- and time-dependent increase in the expression of VEGF-mRNA. The same effect was found with Fas-ligation, although at high concentrations Fas-ligation induced no further increase, but even a decrease of VEGF expression, possibly related to cell damage. Apoptotic cells were rarely observed after LPS-stimulation, but simultaneous incubation with a blocking antibody to VEGF resulted in a significant increase in apoptosis. We hypothesize that endothelial cells are resistant to apoptosis induction by autocrine expression of VEGF under stress conditions.
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PMID:Apoptosis inducers endotoxin and Fas-ligation enhance the expression of vascular endothelial growth factor in human endothelial cells. 1047 96

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is highly expressed in the myocardium under various stimuli including hypoxia and ischemia. On the other hand, lipopolysaccharide (LPS) causes systemic inflammatory response syndrome (SIRS), which consists of systemic pathophysiological changes related to vascular hyperpermeability. To test the hypothesis that VEGF is one of the important mediators of SIRS, we examined effects of LPS on the VEGF expression and secretion in cultured neonatal rat ventricular myocytes. LPS (10 microg/ml) rapidly (within 1 h) augmented the levels of VEGF mRNA in these cells. Pharmacological inhibition of nucleic factor-kappaB or tyrosine kinases did not affect the LPS-induced augmentation of VEGF mRNA expression, while these treatments markedly suppressed the up-regulation of inducible nitric oxide synthase (iNOS) expression by LPS. The VEGF concentrations in the conditioned media were also significantly increased by the LPS treatment of 6 h. In conclusion, LPS augments VEGF expression and secretion in rat ventricular myocytes, suggesting that VEGF may be involved in pathogenesis of SIRS. LPS may induce VEGF mRNA through the signaling pathways that are distinct from those responsible for the iNOS induction.
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PMID:Lipopolysaccharide augments expression and secretion of vascular endothelial growth factor in rat ventricular myocytes. 1067 60

Vascular 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.
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PMID:Expression of vascular endothelial growth factor in human monocyte/macrophages stimulated with lipopolysaccharide. 1120 70

Capillary leakage and alveolar edema are hallmarks of acute lung injury (ALI). Neutrophils and serum macromolecules enter alveoli, promoting inflammation. Vascular endothelial growth factor (VEGF) causes plasma leakage in extrapulmonary vessels. Angiopoietin (Ang)-1 and -4 stabilize vessels, attenuating capillary leakage. We hypothesized that VEGF and Ang-1 and -4 modulate vessel leakage in the lung, contributing to the pathogenesis of ALI. We examined a murine model of lipopolysaccharide (LPS)-induced ALI. C57BL/6 and 129/J mice were studied at baseline and 24, 48, and 96 h after single or multiple doses of aerosolized LPS. Both strains exhibited time- and dose-dependent increases in inflammation and a deterioration of lung mechanics. Bronchoalveolar lavage (BAL) protein levels increased significantly, suggesting capillary leakage. Increased BAL neutrophil and total protein content correlated with time-dependent increased tissue VEGF and decreased Ang-1 and -4 levels, with peak VEGF and minimum Ang-1 and -4 expression after 96 h of LPS challenge. These data suggest that changes in the balance between VEGF and Ang-1 and -4 after LPS exposure may modulate neutrophil influx, protein leakage, and alveolar flooding during early ALI.
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PMID:Angiogenic growth factors in the pathophysiology of a murine model of acute lung injury. 1216 78

Vascular endothelial growth factor (VEGF) plays multifunctional roles in vascular permeability, repair and remodelling processes, in addition to the maintenance of vascular structure and function. In the present study, the potential of airway epithelial cell lines, BEAS-2B cells and A549 cells, to release and express VEGF in unstimulated and stimulated conditions was evaluated. The secretion and expression of VEGF were evaluated by enzyme-linked immunosorbant assay and by reverse transcriptase-polymerase chain reaction. The isoforms of released VEGF were determined by high-performance liquid chromatography. BEAS-2B cells and A549 cells released VEGF constitutively. Interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha augmented the release of VEGF in a time- and dose-dependent manner. The released VEGF was 165 amino acid residues in either condition. Pseudomonas aeruginosa lipopolysaccharide (LPS), interferon (IFN)-gamma, smoke extract (SE), neutrophil elastase (NE), and bradykinin stimulated the release of VEGF. Keracinocyte growth factor (KGF), which reduces vascular permeability, also stimulated both cells to release VEGF. VEGF messenger ribonucleic acid (mRNA) was expressed both time- and dose-dependently at 2 h, and declined after 2 h in response to IL-1beta and TNF-alpha. The expression of VEGF mRNA in airway epithelial cells was also augmented by LPS, IFN-gamma, SE, NE, and KGF stimulation. These data suggest that airway epithelial cells may regulate the maintenance of vascular structure and function, as well as vascular permeability, repair and remodelling processes, in a variety of lung conditions by expressing vascular endothelial growth factor.
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PMID:Vascular endothelial growth factor mRNA and protein expression in airway epithelial cell lines in vitro. 1250 3

Vascular endothelial growth factor (VEGF) is the most endothelial cell-specific angiogenic factor characterised to date, and it is produced by a variety of cell types. In macrophages, VEGF has been shown to be upregulated by the inflammatory mediator lipopolysaccharide (LPS) and by engagement of CD40 by CD40 ligand (CD40L). Because LPS and CD40L activate nuclear factor-kappaB (NF-kappaB) in monocytes, we investigated in this study whether VEGF production in macrophages, when stimulated with either LPS or CD40L, is NF-kappaB-dependent. We used adenoviral constructs over-expressing either IkappaBalpha (AdvIkappaBalpha), the endogenous inhibitor of NF-kappaB, or a kinase-defective mutant of IKK-2 (AdvIKK-2dn), an upstream activator of IkappaBalpha, to infect normal human monocyte-derived macrophages. We observed that LPS-induced production of VEGF in human macrophages was almost completely inhibited (>90%) following adenoviral transfer of IkappaBalpha. In addition, we observed significant inhibition of the CD40L-induced VEGF production in macrophages following infection with AdvIkappaBalpha. Expression of IKK-2dn in macrophages decreased VEGF production in response to LPS or CD40L by approximately 50%, suggesting that in addition to IKK-2, other kinases might be involved in NF-kappaB activation. These results show for the first time that VEGF production in human macrophages is NF-kappaB dependent. NF-kappaB regulates many of the genes involved in immune and inflammatory responses, and our study adds the angiogenic cytokine VEGF to the list of NF-kappaB-dependent cytokines.
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PMID:VEGF expression in human macrophages is NF-kappaB-dependent: studies using adenoviruses expressing the endogenous NF-kappaB inhibitor IkappaBalpha and a kinase-defective form of the IkappaB kinase 2. 1253 67

Vascular endothelial growth factor (VEGF) has recently attracted attention as a potent inducer of vascular permeability and angiogenesis. Aberrant angiogenesis is often associated with lesion formation in chronic periodontitis. The aim of the present study was to investigate the properties of VEGF expression in human gingival fibroblasts (HGF) culture. HGF were stimulated with lipopolysaccharide (LPS), vesicle (Ve) and outer membrane protein (OMP) from Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. HGF constitutively produced VEGF and levels were significantly enhanced (P < 0.01) by stimulation with Ve and OMP from A. actinomycetemcomitans and P. gingivalis at concentrations of 10 microg/ml or higher. On the other hand, VEGF levels were not increased by LPS stimulation. VEGF mRNA expression was also observed in Ve- and OMP-stimulated HGF. A vascular permeability enhancement (VPE) assay was performed using guinea pigs to ascertain whether supernatant from cultures of Ve- and OMP-stimulated HGF enhance vascular permeability in vivo. Supernatant from cultures of Ve- and OMP-stimulated HGF strongly induced VPE. This was markedly suppressed upon simultaneous injection of anti-VEGF polyclonal antibodies with the supernatant. Heating and protease treatment of the stimulants reduced the VEGF enhancing levels in Ve and OMP in vitro. These results suggest that Ve and OMP may be crucial heat-labile and protease-sensitive components of periodontal pathogens that enhance VEGF expression. In addition, VEGF might be associated with the etiology of periodontitis in its early stages according to neovascularization stimulated by periodontal pathogens causing swelling and edema.
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PMID:Enhanced expression of vascular endothelial growth factor by periodontal pathogens in gingival fibroblasts. 1255 42


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